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v5.4
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *	Intel IO-APIC support for multi-Pentium hosts.
   4 *
   5 *	Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
   6 *
   7 *	Many thanks to Stig Venaas for trying out countless experimental
   8 *	patches and reporting/debugging problems patiently!
   9 *
  10 *	(c) 1999, Multiple IO-APIC support, developed by
  11 *	Ken-ichi Yaku <yaku@css1.kbnes.nec.co.jp> and
  12 *      Hidemi Kishimoto <kisimoto@css1.kbnes.nec.co.jp>,
  13 *	further tested and cleaned up by Zach Brown <zab@redhat.com>
  14 *	and Ingo Molnar <mingo@redhat.com>
  15 *
  16 *	Fixes
  17 *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
  18 *					thanks to Eric Gilmore
  19 *					and Rolf G. Tews
  20 *					for testing these extensively
  21 *	Paul Diefenbaugh	:	Added full ACPI support
  22 *
  23 * Historical information which is worth to be preserved:
  24 *
  25 * - SiS APIC rmw bug:
  26 *
  27 *	We used to have a workaround for a bug in SiS chips which
  28 *	required to rewrite the index register for a read-modify-write
  29 *	operation as the chip lost the index information which was
  30 *	setup for the read already. We cache the data now, so that
  31 *	workaround has been removed.
  32 */
  33
  34#include <linux/mm.h>
  35#include <linux/interrupt.h>
  36#include <linux/irq.h>
  37#include <linux/init.h>
  38#include <linux/delay.h>
  39#include <linux/sched.h>
  40#include <linux/pci.h>
  41#include <linux/mc146818rtc.h>
  42#include <linux/compiler.h>
  43#include <linux/acpi.h>
  44#include <linux/export.h>
  45#include <linux/syscore_ops.h>
  46#include <linux/freezer.h>
  47#include <linux/kthread.h>
  48#include <linux/jiffies.h>	/* time_after() */
  49#include <linux/slab.h>
  50#include <linux/memblock.h>
  51
  52#include <asm/irqdomain.h>
  53#include <asm/io.h>
  54#include <asm/smp.h>
  55#include <asm/cpu.h>
  56#include <asm/desc.h>
  57#include <asm/proto.h>
  58#include <asm/acpi.h>
  59#include <asm/dma.h>
  60#include <asm/timer.h>
  61#include <asm/time.h>
  62#include <asm/i8259.h>
  63#include <asm/setup.h>
  64#include <asm/irq_remapping.h>
  65#include <asm/hw_irq.h>
  66
  67#include <asm/apic.h>
  68
  69#define	for_each_ioapic(idx)		\
  70	for ((idx) = 0; (idx) < nr_ioapics; (idx)++)
  71#define	for_each_ioapic_reverse(idx)	\
  72	for ((idx) = nr_ioapics - 1; (idx) >= 0; (idx)--)
  73#define	for_each_pin(idx, pin)		\
  74	for ((pin) = 0; (pin) < ioapics[(idx)].nr_registers; (pin)++)
  75#define	for_each_ioapic_pin(idx, pin)	\
  76	for_each_ioapic((idx))		\
  77		for_each_pin((idx), (pin))
  78#define for_each_irq_pin(entry, head) \
  79	list_for_each_entry(entry, &head, list)
  80
  81static DEFINE_RAW_SPINLOCK(ioapic_lock);
  82static DEFINE_MUTEX(ioapic_mutex);
  83static unsigned int ioapic_dynirq_base;
  84static int ioapic_initialized;
  85
  86struct irq_pin_list {
  87	struct list_head list;
  88	int apic, pin;
  89};
  90
  91struct mp_chip_data {
  92	struct list_head irq_2_pin;
  93	struct IO_APIC_route_entry entry;
  94	int trigger;
  95	int polarity;
  96	u32 count;
  97	bool isa_irq;
  98};
  99
 100struct mp_ioapic_gsi {
 101	u32 gsi_base;
 102	u32 gsi_end;
 103};
 104
 105static struct ioapic {
 106	/*
 107	 * # of IRQ routing registers
 108	 */
 109	int nr_registers;
 110	/*
 111	 * Saved state during suspend/resume, or while enabling intr-remap.
 112	 */
 113	struct IO_APIC_route_entry *saved_registers;
 114	/* I/O APIC config */
 115	struct mpc_ioapic mp_config;
 116	/* IO APIC gsi routing info */
 117	struct mp_ioapic_gsi  gsi_config;
 118	struct ioapic_domain_cfg irqdomain_cfg;
 119	struct irq_domain *irqdomain;
 120	struct resource *iomem_res;
 121} ioapics[MAX_IO_APICS];
 122
 123#define mpc_ioapic_ver(ioapic_idx)	ioapics[ioapic_idx].mp_config.apicver
 124
 125int mpc_ioapic_id(int ioapic_idx)
 126{
 127	return ioapics[ioapic_idx].mp_config.apicid;
 128}
 129
 130unsigned int mpc_ioapic_addr(int ioapic_idx)
 131{
 132	return ioapics[ioapic_idx].mp_config.apicaddr;
 133}
 134
 135static inline struct mp_ioapic_gsi *mp_ioapic_gsi_routing(int ioapic_idx)
 136{
 137	return &ioapics[ioapic_idx].gsi_config;
 138}
 139
 140static inline int mp_ioapic_pin_count(int ioapic)
 141{
 142	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic);
 143
 144	return gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
 145}
 146
 147static inline u32 mp_pin_to_gsi(int ioapic, int pin)
 148{
 149	return mp_ioapic_gsi_routing(ioapic)->gsi_base + pin;
 150}
 151
 152static inline bool mp_is_legacy_irq(int irq)
 153{
 154	return irq >= 0 && irq < nr_legacy_irqs();
 155}
 156
 157/*
 158 * Initialize all legacy IRQs and all pins on the first IOAPIC
 159 * if we have legacy interrupt controller. Kernel boot option "pirq="
 160 * may rely on non-legacy pins on the first IOAPIC.
 161 */
 162static inline int mp_init_irq_at_boot(int ioapic, int irq)
 163{
 164	if (!nr_legacy_irqs())
 165		return 0;
 166
 167	return ioapic == 0 || mp_is_legacy_irq(irq);
 168}
 169
 170static inline struct irq_domain *mp_ioapic_irqdomain(int ioapic)
 171{
 172	return ioapics[ioapic].irqdomain;
 173}
 174
 175int nr_ioapics;
 176
 177/* The one past the highest gsi number used */
 178u32 gsi_top;
 179
 180/* MP IRQ source entries */
 181struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
 182
 183/* # of MP IRQ source entries */
 184int mp_irq_entries;
 185
 186#ifdef CONFIG_EISA
 187int mp_bus_id_to_type[MAX_MP_BUSSES];
 188#endif
 189
 190DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES);
 191
 192int skip_ioapic_setup;
 193
 194/**
 195 * disable_ioapic_support() - disables ioapic support at runtime
 196 */
 197void disable_ioapic_support(void)
 198{
 199#ifdef CONFIG_PCI
 200	noioapicquirk = 1;
 201	noioapicreroute = -1;
 202#endif
 203	skip_ioapic_setup = 1;
 204}
 205
 206static int __init parse_noapic(char *str)
 207{
 208	/* disable IO-APIC */
 209	disable_ioapic_support();
 210	return 0;
 211}
 212early_param("noapic", parse_noapic);
 213
 214/* Will be called in mpparse/acpi/sfi codes for saving IRQ info */
 215void mp_save_irq(struct mpc_intsrc *m)
 216{
 217	int i;
 218
 219	apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
 220		" IRQ %02x, APIC ID %x, APIC INT %02x\n",
 221		m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbus,
 222		m->srcbusirq, m->dstapic, m->dstirq);
 223
 224	for (i = 0; i < mp_irq_entries; i++) {
 225		if (!memcmp(&mp_irqs[i], m, sizeof(*m)))
 226			return;
 227	}
 228
 229	memcpy(&mp_irqs[mp_irq_entries], m, sizeof(*m));
 230	if (++mp_irq_entries == MAX_IRQ_SOURCES)
 231		panic("Max # of irq sources exceeded!!\n");
 232}
 233
 234static void alloc_ioapic_saved_registers(int idx)
 235{
 236	size_t size;
 237
 238	if (ioapics[idx].saved_registers)
 239		return;
 240
 241	size = sizeof(struct IO_APIC_route_entry) * ioapics[idx].nr_registers;
 242	ioapics[idx].saved_registers = kzalloc(size, GFP_KERNEL);
 243	if (!ioapics[idx].saved_registers)
 244		pr_err("IOAPIC %d: suspend/resume impossible!\n", idx);
 245}
 246
 247static void free_ioapic_saved_registers(int idx)
 248{
 249	kfree(ioapics[idx].saved_registers);
 250	ioapics[idx].saved_registers = NULL;
 251}
 252
 253int __init arch_early_ioapic_init(void)
 254{
 255	int i;
 256
 257	if (!nr_legacy_irqs())
 258		io_apic_irqs = ~0UL;
 259
 260	for_each_ioapic(i)
 261		alloc_ioapic_saved_registers(i);
 262
 263	return 0;
 264}
 265
 266struct io_apic {
 267	unsigned int index;
 268	unsigned int unused[3];
 269	unsigned int data;
 270	unsigned int unused2[11];
 271	unsigned int eoi;
 272};
 273
 274static __attribute_const__ struct io_apic __iomem *io_apic_base(int idx)
 275{
 276	return (void __iomem *) __fix_to_virt(FIX_IO_APIC_BASE_0 + idx)
 277		+ (mpc_ioapic_addr(idx) & ~PAGE_MASK);
 278}
 279
 280static inline void io_apic_eoi(unsigned int apic, unsigned int vector)
 281{
 282	struct io_apic __iomem *io_apic = io_apic_base(apic);
 283	writel(vector, &io_apic->eoi);
 284}
 285
 286unsigned int native_io_apic_read(unsigned int apic, unsigned int reg)
 287{
 288	struct io_apic __iomem *io_apic = io_apic_base(apic);
 289	writel(reg, &io_apic->index);
 290	return readl(&io_apic->data);
 291}
 292
 293static void io_apic_write(unsigned int apic, unsigned int reg,
 294			  unsigned int value)
 295{
 296	struct io_apic __iomem *io_apic = io_apic_base(apic);
 297
 298	writel(reg, &io_apic->index);
 299	writel(value, &io_apic->data);
 300}
 301
 302union entry_union {
 303	struct { u32 w1, w2; };
 304	struct IO_APIC_route_entry entry;
 305};
 306
 307static struct IO_APIC_route_entry __ioapic_read_entry(int apic, int pin)
 308{
 309	union entry_union eu;
 310
 311	eu.w1 = io_apic_read(apic, 0x10 + 2 * pin);
 312	eu.w2 = io_apic_read(apic, 0x11 + 2 * pin);
 313
 314	return eu.entry;
 315}
 316
 317static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
 318{
 319	union entry_union eu;
 320	unsigned long flags;
 321
 322	raw_spin_lock_irqsave(&ioapic_lock, flags);
 323	eu.entry = __ioapic_read_entry(apic, pin);
 324	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 325
 326	return eu.entry;
 327}
 328
 329/*
 330 * When we write a new IO APIC routing entry, we need to write the high
 331 * word first! If the mask bit in the low word is clear, we will enable
 332 * the interrupt, and we need to make sure the entry is fully populated
 333 * before that happens.
 334 */
 335static void __ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
 336{
 337	union entry_union eu = {{0, 0}};
 338
 339	eu.entry = e;
 340	io_apic_write(apic, 0x11 + 2*pin, eu.w2);
 341	io_apic_write(apic, 0x10 + 2*pin, eu.w1);
 342}
 343
 344static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
 345{
 346	unsigned long flags;
 347
 348	raw_spin_lock_irqsave(&ioapic_lock, flags);
 349	__ioapic_write_entry(apic, pin, e);
 350	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 351}
 352
 353/*
 354 * When we mask an IO APIC routing entry, we need to write the low
 355 * word first, in order to set the mask bit before we change the
 356 * high bits!
 357 */
 358static void ioapic_mask_entry(int apic, int pin)
 359{
 360	unsigned long flags;
 361	union entry_union eu = { .entry.mask = IOAPIC_MASKED };
 362
 363	raw_spin_lock_irqsave(&ioapic_lock, flags);
 364	io_apic_write(apic, 0x10 + 2*pin, eu.w1);
 365	io_apic_write(apic, 0x11 + 2*pin, eu.w2);
 366	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 367}
 368
 369/*
 370 * The common case is 1:1 IRQ<->pin mappings. Sometimes there are
 371 * shared ISA-space IRQs, so we have to support them. We are super
 372 * fast in the common case, and fast for shared ISA-space IRQs.
 373 */
 374static int __add_pin_to_irq_node(struct mp_chip_data *data,
 375				 int node, int apic, int pin)
 376{
 377	struct irq_pin_list *entry;
 378
 379	/* don't allow duplicates */
 380	for_each_irq_pin(entry, data->irq_2_pin)
 381		if (entry->apic == apic && entry->pin == pin)
 382			return 0;
 383
 384	entry = kzalloc_node(sizeof(struct irq_pin_list), GFP_ATOMIC, node);
 385	if (!entry) {
 386		pr_err("can not alloc irq_pin_list (%d,%d,%d)\n",
 387		       node, apic, pin);
 388		return -ENOMEM;
 389	}
 390	entry->apic = apic;
 391	entry->pin = pin;
 392	list_add_tail(&entry->list, &data->irq_2_pin);
 393
 394	return 0;
 395}
 396
 397static void __remove_pin_from_irq(struct mp_chip_data *data, int apic, int pin)
 398{
 399	struct irq_pin_list *tmp, *entry;
 400
 401	list_for_each_entry_safe(entry, tmp, &data->irq_2_pin, list)
 402		if (entry->apic == apic && entry->pin == pin) {
 403			list_del(&entry->list);
 404			kfree(entry);
 405			return;
 406		}
 407}
 408
 409static void add_pin_to_irq_node(struct mp_chip_data *data,
 410				int node, int apic, int pin)
 411{
 412	if (__add_pin_to_irq_node(data, node, apic, pin))
 413		panic("IO-APIC: failed to add irq-pin. Can not proceed\n");
 414}
 415
 416/*
 417 * Reroute an IRQ to a different pin.
 418 */
 419static void __init replace_pin_at_irq_node(struct mp_chip_data *data, int node,
 420					   int oldapic, int oldpin,
 421					   int newapic, int newpin)
 422{
 423	struct irq_pin_list *entry;
 424
 425	for_each_irq_pin(entry, data->irq_2_pin) {
 426		if (entry->apic == oldapic && entry->pin == oldpin) {
 427			entry->apic = newapic;
 428			entry->pin = newpin;
 429			/* every one is different, right? */
 430			return;
 431		}
 432	}
 433
 434	/* old apic/pin didn't exist, so just add new ones */
 435	add_pin_to_irq_node(data, node, newapic, newpin);
 436}
 437
 438static void io_apic_modify_irq(struct mp_chip_data *data,
 439			       int mask_and, int mask_or,
 440			       void (*final)(struct irq_pin_list *entry))
 441{
 442	union entry_union eu;
 443	struct irq_pin_list *entry;
 444
 445	eu.entry = data->entry;
 446	eu.w1 &= mask_and;
 447	eu.w1 |= mask_or;
 448	data->entry = eu.entry;
 449
 450	for_each_irq_pin(entry, data->irq_2_pin) {
 451		io_apic_write(entry->apic, 0x10 + 2 * entry->pin, eu.w1);
 452		if (final)
 453			final(entry);
 454	}
 455}
 456
 457static void io_apic_sync(struct irq_pin_list *entry)
 458{
 459	/*
 460	 * Synchronize the IO-APIC and the CPU by doing
 461	 * a dummy read from the IO-APIC
 462	 */
 463	struct io_apic __iomem *io_apic;
 464
 465	io_apic = io_apic_base(entry->apic);
 466	readl(&io_apic->data);
 467}
 468
 469static void mask_ioapic_irq(struct irq_data *irq_data)
 470{
 471	struct mp_chip_data *data = irq_data->chip_data;
 472	unsigned long flags;
 473
 474	raw_spin_lock_irqsave(&ioapic_lock, flags);
 475	io_apic_modify_irq(data, ~0, IO_APIC_REDIR_MASKED, &io_apic_sync);
 476	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 477}
 478
 479static void __unmask_ioapic(struct mp_chip_data *data)
 480{
 481	io_apic_modify_irq(data, ~IO_APIC_REDIR_MASKED, 0, NULL);
 482}
 483
 484static void unmask_ioapic_irq(struct irq_data *irq_data)
 485{
 486	struct mp_chip_data *data = irq_data->chip_data;
 487	unsigned long flags;
 488
 489	raw_spin_lock_irqsave(&ioapic_lock, flags);
 490	__unmask_ioapic(data);
 491	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 492}
 493
 494/*
 495 * IO-APIC versions below 0x20 don't support EOI register.
 496 * For the record, here is the information about various versions:
 497 *     0Xh     82489DX
 498 *     1Xh     I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
 499 *     2Xh     I/O(x)APIC which is PCI 2.2 Compliant
 500 *     30h-FFh Reserved
 501 *
 502 * Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
 503 * version as 0x2. This is an error with documentation and these ICH chips
 504 * use io-apic's of version 0x20.
 505 *
 506 * For IO-APIC's with EOI register, we use that to do an explicit EOI.
 507 * Otherwise, we simulate the EOI message manually by changing the trigger
 508 * mode to edge and then back to level, with RTE being masked during this.
 509 */
 510static void __eoi_ioapic_pin(int apic, int pin, int vector)
 511{
 512	if (mpc_ioapic_ver(apic) >= 0x20) {
 513		io_apic_eoi(apic, vector);
 514	} else {
 515		struct IO_APIC_route_entry entry, entry1;
 516
 517		entry = entry1 = __ioapic_read_entry(apic, pin);
 518
 519		/*
 520		 * Mask the entry and change the trigger mode to edge.
 521		 */
 522		entry1.mask = IOAPIC_MASKED;
 523		entry1.trigger = IOAPIC_EDGE;
 524
 525		__ioapic_write_entry(apic, pin, entry1);
 526
 527		/*
 528		 * Restore the previous level triggered entry.
 529		 */
 530		__ioapic_write_entry(apic, pin, entry);
 531	}
 532}
 533
 534static void eoi_ioapic_pin(int vector, struct mp_chip_data *data)
 535{
 536	unsigned long flags;
 537	struct irq_pin_list *entry;
 538
 539	raw_spin_lock_irqsave(&ioapic_lock, flags);
 540	for_each_irq_pin(entry, data->irq_2_pin)
 541		__eoi_ioapic_pin(entry->apic, entry->pin, vector);
 542	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 543}
 544
 545static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
 546{
 547	struct IO_APIC_route_entry entry;
 548
 549	/* Check delivery_mode to be sure we're not clearing an SMI pin */
 550	entry = ioapic_read_entry(apic, pin);
 551	if (entry.delivery_mode == dest_SMI)
 552		return;
 553
 554	/*
 555	 * Make sure the entry is masked and re-read the contents to check
 556	 * if it is a level triggered pin and if the remote-IRR is set.
 557	 */
 558	if (entry.mask == IOAPIC_UNMASKED) {
 559		entry.mask = IOAPIC_MASKED;
 560		ioapic_write_entry(apic, pin, entry);
 561		entry = ioapic_read_entry(apic, pin);
 562	}
 563
 564	if (entry.irr) {
 565		unsigned long flags;
 566
 567		/*
 568		 * Make sure the trigger mode is set to level. Explicit EOI
 569		 * doesn't clear the remote-IRR if the trigger mode is not
 570		 * set to level.
 571		 */
 572		if (entry.trigger == IOAPIC_EDGE) {
 573			entry.trigger = IOAPIC_LEVEL;
 574			ioapic_write_entry(apic, pin, entry);
 575		}
 576		raw_spin_lock_irqsave(&ioapic_lock, flags);
 577		__eoi_ioapic_pin(apic, pin, entry.vector);
 578		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 579	}
 580
 581	/*
 582	 * Clear the rest of the bits in the IO-APIC RTE except for the mask
 583	 * bit.
 584	 */
 585	ioapic_mask_entry(apic, pin);
 586	entry = ioapic_read_entry(apic, pin);
 587	if (entry.irr)
 588		pr_err("Unable to reset IRR for apic: %d, pin :%d\n",
 589		       mpc_ioapic_id(apic), pin);
 590}
 591
 592void clear_IO_APIC (void)
 593{
 594	int apic, pin;
 595
 596	for_each_ioapic_pin(apic, pin)
 597		clear_IO_APIC_pin(apic, pin);
 598}
 599
 600#ifdef CONFIG_X86_32
 601/*
 602 * support for broken MP BIOSs, enables hand-redirection of PIRQ0-7 to
 603 * specific CPU-side IRQs.
 604 */
 605
 606#define MAX_PIRQS 8
 607static int pirq_entries[MAX_PIRQS] = {
 608	[0 ... MAX_PIRQS - 1] = -1
 609};
 610
 611static int __init ioapic_pirq_setup(char *str)
 612{
 613	int i, max;
 614	int ints[MAX_PIRQS+1];
 615
 616	get_options(str, ARRAY_SIZE(ints), ints);
 617
 618	apic_printk(APIC_VERBOSE, KERN_INFO
 619			"PIRQ redirection, working around broken MP-BIOS.\n");
 620	max = MAX_PIRQS;
 621	if (ints[0] < MAX_PIRQS)
 622		max = ints[0];
 623
 624	for (i = 0; i < max; i++) {
 625		apic_printk(APIC_VERBOSE, KERN_DEBUG
 626				"... PIRQ%d -> IRQ %d\n", i, ints[i+1]);
 627		/*
 628		 * PIRQs are mapped upside down, usually.
 629		 */
 630		pirq_entries[MAX_PIRQS-i-1] = ints[i+1];
 631	}
 632	return 1;
 633}
 634
 635__setup("pirq=", ioapic_pirq_setup);
 636#endif /* CONFIG_X86_32 */
 637
 638/*
 639 * Saves all the IO-APIC RTE's
 640 */
 641int save_ioapic_entries(void)
 642{
 643	int apic, pin;
 644	int err = 0;
 645
 646	for_each_ioapic(apic) {
 647		if (!ioapics[apic].saved_registers) {
 648			err = -ENOMEM;
 649			continue;
 650		}
 651
 652		for_each_pin(apic, pin)
 653			ioapics[apic].saved_registers[pin] =
 654				ioapic_read_entry(apic, pin);
 655	}
 656
 657	return err;
 658}
 659
 660/*
 661 * Mask all IO APIC entries.
 662 */
 663void mask_ioapic_entries(void)
 664{
 665	int apic, pin;
 666
 667	for_each_ioapic(apic) {
 668		if (!ioapics[apic].saved_registers)
 669			continue;
 670
 671		for_each_pin(apic, pin) {
 672			struct IO_APIC_route_entry entry;
 673
 674			entry = ioapics[apic].saved_registers[pin];
 675			if (entry.mask == IOAPIC_UNMASKED) {
 676				entry.mask = IOAPIC_MASKED;
 677				ioapic_write_entry(apic, pin, entry);
 678			}
 679		}
 680	}
 681}
 682
 683/*
 684 * Restore IO APIC entries which was saved in the ioapic structure.
 685 */
 686int restore_ioapic_entries(void)
 687{
 688	int apic, pin;
 689
 690	for_each_ioapic(apic) {
 691		if (!ioapics[apic].saved_registers)
 692			continue;
 693
 694		for_each_pin(apic, pin)
 695			ioapic_write_entry(apic, pin,
 696					   ioapics[apic].saved_registers[pin]);
 697	}
 698	return 0;
 699}
 700
 701/*
 702 * Find the IRQ entry number of a certain pin.
 703 */
 704static int find_irq_entry(int ioapic_idx, int pin, int type)
 705{
 706	int i;
 707
 708	for (i = 0; i < mp_irq_entries; i++)
 709		if (mp_irqs[i].irqtype == type &&
 710		    (mp_irqs[i].dstapic == mpc_ioapic_id(ioapic_idx) ||
 711		     mp_irqs[i].dstapic == MP_APIC_ALL) &&
 712		    mp_irqs[i].dstirq == pin)
 713			return i;
 714
 715	return -1;
 716}
 717
 718/*
 719 * Find the pin to which IRQ[irq] (ISA) is connected
 720 */
 721static int __init find_isa_irq_pin(int irq, int type)
 722{
 723	int i;
 724
 725	for (i = 0; i < mp_irq_entries; i++) {
 726		int lbus = mp_irqs[i].srcbus;
 727
 728		if (test_bit(lbus, mp_bus_not_pci) &&
 729		    (mp_irqs[i].irqtype == type) &&
 730		    (mp_irqs[i].srcbusirq == irq))
 731
 732			return mp_irqs[i].dstirq;
 733	}
 734	return -1;
 735}
 736
 737static int __init find_isa_irq_apic(int irq, int type)
 738{
 739	int i;
 740
 741	for (i = 0; i < mp_irq_entries; i++) {
 742		int lbus = mp_irqs[i].srcbus;
 743
 744		if (test_bit(lbus, mp_bus_not_pci) &&
 745		    (mp_irqs[i].irqtype == type) &&
 746		    (mp_irqs[i].srcbusirq == irq))
 747			break;
 748	}
 749
 750	if (i < mp_irq_entries) {
 751		int ioapic_idx;
 752
 753		for_each_ioapic(ioapic_idx)
 754			if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic)
 755				return ioapic_idx;
 756	}
 757
 758	return -1;
 759}
 760
 761#ifdef CONFIG_EISA
 762/*
 763 * EISA Edge/Level control register, ELCR
 764 */
 765static int EISA_ELCR(unsigned int irq)
 766{
 767	if (irq < nr_legacy_irqs()) {
 768		unsigned int port = 0x4d0 + (irq >> 3);
 769		return (inb(port) >> (irq & 7)) & 1;
 770	}
 771	apic_printk(APIC_VERBOSE, KERN_INFO
 772			"Broken MPtable reports ISA irq %d\n", irq);
 773	return 0;
 774}
 775
 776#endif
 777
 778/* ISA interrupts are always active high edge triggered,
 779 * when listed as conforming in the MP table. */
 780
 781#define default_ISA_trigger(idx)	(IOAPIC_EDGE)
 782#define default_ISA_polarity(idx)	(IOAPIC_POL_HIGH)
 783
 784/* EISA interrupts are always polarity zero and can be edge or level
 785 * trigger depending on the ELCR value.  If an interrupt is listed as
 786 * EISA conforming in the MP table, that means its trigger type must
 787 * be read in from the ELCR */
 788
 789#define default_EISA_trigger(idx)	(EISA_ELCR(mp_irqs[idx].srcbusirq))
 790#define default_EISA_polarity(idx)	default_ISA_polarity(idx)
 791
 792/* PCI interrupts are always active low level triggered,
 793 * when listed as conforming in the MP table. */
 794
 795#define default_PCI_trigger(idx)	(IOAPIC_LEVEL)
 796#define default_PCI_polarity(idx)	(IOAPIC_POL_LOW)
 797
 798static int irq_polarity(int idx)
 799{
 800	int bus = mp_irqs[idx].srcbus;
 801
 802	/*
 803	 * Determine IRQ line polarity (high active or low active):
 804	 */
 805	switch (mp_irqs[idx].irqflag & MP_IRQPOL_MASK) {
 806	case MP_IRQPOL_DEFAULT:
 807		/* conforms to spec, ie. bus-type dependent polarity */
 808		if (test_bit(bus, mp_bus_not_pci))
 809			return default_ISA_polarity(idx);
 810		else
 811			return default_PCI_polarity(idx);
 812	case MP_IRQPOL_ACTIVE_HIGH:
 813		return IOAPIC_POL_HIGH;
 814	case MP_IRQPOL_RESERVED:
 815		pr_warn("IOAPIC: Invalid polarity: 2, defaulting to low\n");
 816		/* fall through */
 817	case MP_IRQPOL_ACTIVE_LOW:
 818	default: /* Pointless default required due to do gcc stupidity */
 819		return IOAPIC_POL_LOW;
 820	}
 821}
 822
 823#ifdef CONFIG_EISA
 824static int eisa_irq_trigger(int idx, int bus, int trigger)
 825{
 826	switch (mp_bus_id_to_type[bus]) {
 827	case MP_BUS_PCI:
 828	case MP_BUS_ISA:
 829		return trigger;
 830	case MP_BUS_EISA:
 831		return default_EISA_trigger(idx);
 832	}
 833	pr_warn("IOAPIC: Invalid srcbus: %d defaulting to level\n", bus);
 834	return IOAPIC_LEVEL;
 835}
 836#else
 837static inline int eisa_irq_trigger(int idx, int bus, int trigger)
 838{
 839	return trigger;
 840}
 841#endif
 842
 843static int irq_trigger(int idx)
 844{
 845	int bus = mp_irqs[idx].srcbus;
 846	int trigger;
 847
 848	/*
 849	 * Determine IRQ trigger mode (edge or level sensitive):
 850	 */
 851	switch (mp_irqs[idx].irqflag & MP_IRQTRIG_MASK) {
 852	case MP_IRQTRIG_DEFAULT:
 853		/* conforms to spec, ie. bus-type dependent trigger mode */
 854		if (test_bit(bus, mp_bus_not_pci))
 855			trigger = default_ISA_trigger(idx);
 856		else
 857			trigger = default_PCI_trigger(idx);
 858		/* Take EISA into account */
 859		return eisa_irq_trigger(idx, bus, trigger);
 860	case MP_IRQTRIG_EDGE:
 861		return IOAPIC_EDGE;
 862	case MP_IRQTRIG_RESERVED:
 863		pr_warn("IOAPIC: Invalid trigger mode 2 defaulting to level\n");
 864		/* fall through */
 865	case MP_IRQTRIG_LEVEL:
 866	default: /* Pointless default required due to do gcc stupidity */
 867		return IOAPIC_LEVEL;
 868	}
 869}
 870
 871void ioapic_set_alloc_attr(struct irq_alloc_info *info, int node,
 872			   int trigger, int polarity)
 873{
 874	init_irq_alloc_info(info, NULL);
 875	info->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
 876	info->ioapic_node = node;
 877	info->ioapic_trigger = trigger;
 878	info->ioapic_polarity = polarity;
 879	info->ioapic_valid = 1;
 880}
 881
 882#ifndef CONFIG_ACPI
 883int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity);
 884#endif
 885
 886static void ioapic_copy_alloc_attr(struct irq_alloc_info *dst,
 887				   struct irq_alloc_info *src,
 888				   u32 gsi, int ioapic_idx, int pin)
 889{
 890	int trigger, polarity;
 891
 892	copy_irq_alloc_info(dst, src);
 893	dst->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
 894	dst->ioapic_id = mpc_ioapic_id(ioapic_idx);
 895	dst->ioapic_pin = pin;
 896	dst->ioapic_valid = 1;
 897	if (src && src->ioapic_valid) {
 898		dst->ioapic_node = src->ioapic_node;
 899		dst->ioapic_trigger = src->ioapic_trigger;
 900		dst->ioapic_polarity = src->ioapic_polarity;
 901	} else {
 902		dst->ioapic_node = NUMA_NO_NODE;
 903		if (acpi_get_override_irq(gsi, &trigger, &polarity) >= 0) {
 904			dst->ioapic_trigger = trigger;
 905			dst->ioapic_polarity = polarity;
 906		} else {
 907			/*
 908			 * PCI interrupts are always active low level
 909			 * triggered.
 910			 */
 911			dst->ioapic_trigger = IOAPIC_LEVEL;
 912			dst->ioapic_polarity = IOAPIC_POL_LOW;
 913		}
 914	}
 915}
 916
 917static int ioapic_alloc_attr_node(struct irq_alloc_info *info)
 918{
 919	return (info && info->ioapic_valid) ? info->ioapic_node : NUMA_NO_NODE;
 920}
 921
 922static void mp_register_handler(unsigned int irq, unsigned long trigger)
 923{
 924	irq_flow_handler_t hdl;
 925	bool fasteoi;
 926
 927	if (trigger) {
 928		irq_set_status_flags(irq, IRQ_LEVEL);
 929		fasteoi = true;
 930	} else {
 931		irq_clear_status_flags(irq, IRQ_LEVEL);
 932		fasteoi = false;
 933	}
 934
 935	hdl = fasteoi ? handle_fasteoi_irq : handle_edge_irq;
 936	__irq_set_handler(irq, hdl, 0, fasteoi ? "fasteoi" : "edge");
 937}
 938
 939static bool mp_check_pin_attr(int irq, struct irq_alloc_info *info)
 940{
 941	struct mp_chip_data *data = irq_get_chip_data(irq);
 942
 943	/*
 944	 * setup_IO_APIC_irqs() programs all legacy IRQs with default trigger
 945	 * and polarity attirbutes. So allow the first user to reprogram the
 946	 * pin with real trigger and polarity attributes.
 947	 */
 948	if (irq < nr_legacy_irqs() && data->count == 1) {
 949		if (info->ioapic_trigger != data->trigger)
 950			mp_register_handler(irq, info->ioapic_trigger);
 951		data->entry.trigger = data->trigger = info->ioapic_trigger;
 952		data->entry.polarity = data->polarity = info->ioapic_polarity;
 953	}
 954
 955	return data->trigger == info->ioapic_trigger &&
 956	       data->polarity == info->ioapic_polarity;
 957}
 958
 959static int alloc_irq_from_domain(struct irq_domain *domain, int ioapic, u32 gsi,
 960				 struct irq_alloc_info *info)
 961{
 962	bool legacy = false;
 963	int irq = -1;
 964	int type = ioapics[ioapic].irqdomain_cfg.type;
 965
 966	switch (type) {
 967	case IOAPIC_DOMAIN_LEGACY:
 968		/*
 969		 * Dynamically allocate IRQ number for non-ISA IRQs in the first
 970		 * 16 GSIs on some weird platforms.
 971		 */
 972		if (!ioapic_initialized || gsi >= nr_legacy_irqs())
 973			irq = gsi;
 974		legacy = mp_is_legacy_irq(irq);
 975		break;
 976	case IOAPIC_DOMAIN_STRICT:
 977		irq = gsi;
 978		break;
 979	case IOAPIC_DOMAIN_DYNAMIC:
 980		break;
 981	default:
 982		WARN(1, "ioapic: unknown irqdomain type %d\n", type);
 983		return -1;
 984	}
 985
 986	return __irq_domain_alloc_irqs(domain, irq, 1,
 987				       ioapic_alloc_attr_node(info),
 988				       info, legacy, NULL);
 989}
 990
 991/*
 992 * Need special handling for ISA IRQs because there may be multiple IOAPIC pins
 993 * sharing the same ISA IRQ number and irqdomain only supports 1:1 mapping
 994 * between IOAPIC pin and IRQ number. A typical IOAPIC has 24 pins, pin 0-15 are
 995 * used for legacy IRQs and pin 16-23 are used for PCI IRQs (PIRQ A-H).
 996 * When ACPI is disabled, only legacy IRQ numbers (IRQ0-15) are available, and
 997 * some BIOSes may use MP Interrupt Source records to override IRQ numbers for
 998 * PIRQs instead of reprogramming the interrupt routing logic. Thus there may be
 999 * multiple pins sharing the same legacy IRQ number when ACPI is disabled.
1000 */
1001static int alloc_isa_irq_from_domain(struct irq_domain *domain,
1002				     int irq, int ioapic, int pin,
1003				     struct irq_alloc_info *info)
1004{
1005	struct mp_chip_data *data;
1006	struct irq_data *irq_data = irq_get_irq_data(irq);
1007	int node = ioapic_alloc_attr_node(info);
1008
1009	/*
1010	 * Legacy ISA IRQ has already been allocated, just add pin to
1011	 * the pin list assoicated with this IRQ and program the IOAPIC
1012	 * entry. The IOAPIC entry
1013	 */
1014	if (irq_data && irq_data->parent_data) {
1015		if (!mp_check_pin_attr(irq, info))
1016			return -EBUSY;
1017		if (__add_pin_to_irq_node(irq_data->chip_data, node, ioapic,
1018					  info->ioapic_pin))
1019			return -ENOMEM;
1020	} else {
1021		info->flags |= X86_IRQ_ALLOC_LEGACY;
1022		irq = __irq_domain_alloc_irqs(domain, irq, 1, node, info, true,
1023					      NULL);
1024		if (irq >= 0) {
1025			irq_data = irq_domain_get_irq_data(domain, irq);
1026			data = irq_data->chip_data;
1027			data->isa_irq = true;
1028		}
1029	}
1030
1031	return irq;
1032}
1033
1034static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
1035			     unsigned int flags, struct irq_alloc_info *info)
1036{
1037	int irq;
1038	bool legacy = false;
1039	struct irq_alloc_info tmp;
1040	struct mp_chip_data *data;
1041	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
1042
1043	if (!domain)
1044		return -ENOSYS;
1045
1046	if (idx >= 0 && test_bit(mp_irqs[idx].srcbus, mp_bus_not_pci)) {
1047		irq = mp_irqs[idx].srcbusirq;
1048		legacy = mp_is_legacy_irq(irq);
1049	}
1050
1051	mutex_lock(&ioapic_mutex);
1052	if (!(flags & IOAPIC_MAP_ALLOC)) {
1053		if (!legacy) {
1054			irq = irq_find_mapping(domain, pin);
1055			if (irq == 0)
1056				irq = -ENOENT;
1057		}
1058	} else {
1059		ioapic_copy_alloc_attr(&tmp, info, gsi, ioapic, pin);
1060		if (legacy)
1061			irq = alloc_isa_irq_from_domain(domain, irq,
1062							ioapic, pin, &tmp);
1063		else if ((irq = irq_find_mapping(domain, pin)) == 0)
1064			irq = alloc_irq_from_domain(domain, ioapic, gsi, &tmp);
1065		else if (!mp_check_pin_attr(irq, &tmp))
1066			irq = -EBUSY;
1067		if (irq >= 0) {
1068			data = irq_get_chip_data(irq);
1069			data->count++;
1070		}
1071	}
1072	mutex_unlock(&ioapic_mutex);
1073
1074	return irq;
1075}
1076
1077static int pin_2_irq(int idx, int ioapic, int pin, unsigned int flags)
1078{
1079	u32 gsi = mp_pin_to_gsi(ioapic, pin);
1080
1081	/*
1082	 * Debugging check, we are in big trouble if this message pops up!
1083	 */
1084	if (mp_irqs[idx].dstirq != pin)
1085		pr_err("broken BIOS or MPTABLE parser, ayiee!!\n");
1086
1087#ifdef CONFIG_X86_32
1088	/*
1089	 * PCI IRQ command line redirection. Yes, limits are hardcoded.
1090	 */
1091	if ((pin >= 16) && (pin <= 23)) {
1092		if (pirq_entries[pin-16] != -1) {
1093			if (!pirq_entries[pin-16]) {
1094				apic_printk(APIC_VERBOSE, KERN_DEBUG
1095						"disabling PIRQ%d\n", pin-16);
1096			} else {
1097				int irq = pirq_entries[pin-16];
1098				apic_printk(APIC_VERBOSE, KERN_DEBUG
1099						"using PIRQ%d -> IRQ %d\n",
1100						pin-16, irq);
1101				return irq;
1102			}
1103		}
1104	}
1105#endif
1106
1107	return  mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, NULL);
1108}
1109
1110int mp_map_gsi_to_irq(u32 gsi, unsigned int flags, struct irq_alloc_info *info)
1111{
1112	int ioapic, pin, idx;
1113
1114	ioapic = mp_find_ioapic(gsi);
1115	if (ioapic < 0)
1116		return -ENODEV;
1117
1118	pin = mp_find_ioapic_pin(ioapic, gsi);
1119	idx = find_irq_entry(ioapic, pin, mp_INT);
1120	if ((flags & IOAPIC_MAP_CHECK) && idx < 0)
1121		return -ENODEV;
1122
1123	return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, info);
1124}
1125
1126void mp_unmap_irq(int irq)
1127{
1128	struct irq_data *irq_data = irq_get_irq_data(irq);
1129	struct mp_chip_data *data;
1130
1131	if (!irq_data || !irq_data->domain)
1132		return;
1133
1134	data = irq_data->chip_data;
1135	if (!data || data->isa_irq)
1136		return;
1137
1138	mutex_lock(&ioapic_mutex);
1139	if (--data->count == 0)
1140		irq_domain_free_irqs(irq, 1);
1141	mutex_unlock(&ioapic_mutex);
1142}
1143
1144/*
1145 * Find a specific PCI IRQ entry.
1146 * Not an __init, possibly needed by modules
1147 */
1148int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin)
1149{
1150	int irq, i, best_ioapic = -1, best_idx = -1;
1151
1152	apic_printk(APIC_DEBUG,
1153		    "querying PCI -> IRQ mapping bus:%d, slot:%d, pin:%d.\n",
1154		    bus, slot, pin);
1155	if (test_bit(bus, mp_bus_not_pci)) {
1156		apic_printk(APIC_VERBOSE,
1157			    "PCI BIOS passed nonexistent PCI bus %d!\n", bus);
1158		return -1;
1159	}
1160
1161	for (i = 0; i < mp_irq_entries; i++) {
1162		int lbus = mp_irqs[i].srcbus;
1163		int ioapic_idx, found = 0;
1164
1165		if (bus != lbus || mp_irqs[i].irqtype != mp_INT ||
1166		    slot != ((mp_irqs[i].srcbusirq >> 2) & 0x1f))
1167			continue;
1168
1169		for_each_ioapic(ioapic_idx)
1170			if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic ||
1171			    mp_irqs[i].dstapic == MP_APIC_ALL) {
1172				found = 1;
1173				break;
1174			}
1175		if (!found)
1176			continue;
1177
1178		/* Skip ISA IRQs */
1179		irq = pin_2_irq(i, ioapic_idx, mp_irqs[i].dstirq, 0);
1180		if (irq > 0 && !IO_APIC_IRQ(irq))
1181			continue;
1182
1183		if (pin == (mp_irqs[i].srcbusirq & 3)) {
1184			best_idx = i;
1185			best_ioapic = ioapic_idx;
1186			goto out;
1187		}
1188
1189		/*
1190		 * Use the first all-but-pin matching entry as a
1191		 * best-guess fuzzy result for broken mptables.
1192		 */
1193		if (best_idx < 0) {
1194			best_idx = i;
1195			best_ioapic = ioapic_idx;
1196		}
1197	}
1198	if (best_idx < 0)
1199		return -1;
1200
1201out:
1202	return pin_2_irq(best_idx, best_ioapic, mp_irqs[best_idx].dstirq,
1203			 IOAPIC_MAP_ALLOC);
1204}
1205EXPORT_SYMBOL(IO_APIC_get_PCI_irq_vector);
1206
1207static struct irq_chip ioapic_chip, ioapic_ir_chip;
1208
1209static void __init setup_IO_APIC_irqs(void)
1210{
1211	unsigned int ioapic, pin;
1212	int idx;
1213
1214	apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");
1215
1216	for_each_ioapic_pin(ioapic, pin) {
1217		idx = find_irq_entry(ioapic, pin, mp_INT);
1218		if (idx < 0)
1219			apic_printk(APIC_VERBOSE,
1220				    KERN_DEBUG " apic %d pin %d not connected\n",
1221				    mpc_ioapic_id(ioapic), pin);
1222		else
1223			pin_2_irq(idx, ioapic, pin,
1224				  ioapic ? 0 : IOAPIC_MAP_ALLOC);
1225	}
1226}
1227
1228void ioapic_zap_locks(void)
1229{
1230	raw_spin_lock_init(&ioapic_lock);
1231}
1232
1233static void io_apic_print_entries(unsigned int apic, unsigned int nr_entries)
1234{
1235	int i;
1236	char buf[256];
1237	struct IO_APIC_route_entry entry;
1238	struct IR_IO_APIC_route_entry *ir_entry = (void *)&entry;
1239
1240	printk(KERN_DEBUG "IOAPIC %d:\n", apic);
1241	for (i = 0; i <= nr_entries; i++) {
1242		entry = ioapic_read_entry(apic, i);
1243		snprintf(buf, sizeof(buf),
1244			 " pin%02x, %s, %s, %s, V(%02X), IRR(%1d), S(%1d)",
1245			 i,
1246			 entry.mask == IOAPIC_MASKED ? "disabled" : "enabled ",
1247			 entry.trigger == IOAPIC_LEVEL ? "level" : "edge ",
1248			 entry.polarity == IOAPIC_POL_LOW ? "low " : "high",
1249			 entry.vector, entry.irr, entry.delivery_status);
1250		if (ir_entry->format)
1251			printk(KERN_DEBUG "%s, remapped, I(%04X),  Z(%X)\n",
1252			       buf, (ir_entry->index2 << 15) | ir_entry->index,
1253			       ir_entry->zero);
1254		else
1255			printk(KERN_DEBUG "%s, %s, D(%02X), M(%1d)\n",
1256			       buf,
1257			       entry.dest_mode == IOAPIC_DEST_MODE_LOGICAL ?
1258			       "logical " : "physical",
1259			       entry.dest, entry.delivery_mode);
1260	}
1261}
1262
1263static void __init print_IO_APIC(int ioapic_idx)
1264{
1265	union IO_APIC_reg_00 reg_00;
1266	union IO_APIC_reg_01 reg_01;
1267	union IO_APIC_reg_02 reg_02;
1268	union IO_APIC_reg_03 reg_03;
1269	unsigned long flags;
1270
1271	raw_spin_lock_irqsave(&ioapic_lock, flags);
1272	reg_00.raw = io_apic_read(ioapic_idx, 0);
1273	reg_01.raw = io_apic_read(ioapic_idx, 1);
1274	if (reg_01.bits.version >= 0x10)
1275		reg_02.raw = io_apic_read(ioapic_idx, 2);
1276	if (reg_01.bits.version >= 0x20)
1277		reg_03.raw = io_apic_read(ioapic_idx, 3);
1278	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1279
1280	printk(KERN_DEBUG "IO APIC #%d......\n", mpc_ioapic_id(ioapic_idx));
1281	printk(KERN_DEBUG ".... register #00: %08X\n", reg_00.raw);
1282	printk(KERN_DEBUG ".......    : physical APIC id: %02X\n", reg_00.bits.ID);
1283	printk(KERN_DEBUG ".......    : Delivery Type: %X\n", reg_00.bits.delivery_type);
1284	printk(KERN_DEBUG ".......    : LTS          : %X\n", reg_00.bits.LTS);
1285
1286	printk(KERN_DEBUG ".... register #01: %08X\n", *(int *)&reg_01);
1287	printk(KERN_DEBUG ".......     : max redirection entries: %02X\n",
1288		reg_01.bits.entries);
1289
1290	printk(KERN_DEBUG ".......     : PRQ implemented: %X\n", reg_01.bits.PRQ);
1291	printk(KERN_DEBUG ".......     : IO APIC version: %02X\n",
1292		reg_01.bits.version);
1293
1294	/*
1295	 * Some Intel chipsets with IO APIC VERSION of 0x1? don't have reg_02,
1296	 * but the value of reg_02 is read as the previous read register
1297	 * value, so ignore it if reg_02 == reg_01.
1298	 */
1299	if (reg_01.bits.version >= 0x10 && reg_02.raw != reg_01.raw) {
1300		printk(KERN_DEBUG ".... register #02: %08X\n", reg_02.raw);
1301		printk(KERN_DEBUG ".......     : arbitration: %02X\n", reg_02.bits.arbitration);
1302	}
1303
1304	/*
1305	 * Some Intel chipsets with IO APIC VERSION of 0x2? don't have reg_02
1306	 * or reg_03, but the value of reg_0[23] is read as the previous read
1307	 * register value, so ignore it if reg_03 == reg_0[12].
1308	 */
1309	if (reg_01.bits.version >= 0x20 && reg_03.raw != reg_02.raw &&
1310	    reg_03.raw != reg_01.raw) {
1311		printk(KERN_DEBUG ".... register #03: %08X\n", reg_03.raw);
1312		printk(KERN_DEBUG ".......     : Boot DT    : %X\n", reg_03.bits.boot_DT);
1313	}
1314
1315	printk(KERN_DEBUG ".... IRQ redirection table:\n");
1316	io_apic_print_entries(ioapic_idx, reg_01.bits.entries);
1317}
1318
1319void __init print_IO_APICs(void)
1320{
1321	int ioapic_idx;
1322	unsigned int irq;
1323
1324	printk(KERN_DEBUG "number of MP IRQ sources: %d.\n", mp_irq_entries);
1325	for_each_ioapic(ioapic_idx)
1326		printk(KERN_DEBUG "number of IO-APIC #%d registers: %d.\n",
1327		       mpc_ioapic_id(ioapic_idx),
1328		       ioapics[ioapic_idx].nr_registers);
1329
1330	/*
1331	 * We are a bit conservative about what we expect.  We have to
1332	 * know about every hardware change ASAP.
1333	 */
1334	printk(KERN_INFO "testing the IO APIC.......................\n");
1335
1336	for_each_ioapic(ioapic_idx)
1337		print_IO_APIC(ioapic_idx);
1338
1339	printk(KERN_DEBUG "IRQ to pin mappings:\n");
1340	for_each_active_irq(irq) {
1341		struct irq_pin_list *entry;
1342		struct irq_chip *chip;
1343		struct mp_chip_data *data;
1344
1345		chip = irq_get_chip(irq);
1346		if (chip != &ioapic_chip && chip != &ioapic_ir_chip)
1347			continue;
1348		data = irq_get_chip_data(irq);
1349		if (!data)
1350			continue;
1351		if (list_empty(&data->irq_2_pin))
1352			continue;
1353
1354		printk(KERN_DEBUG "IRQ%d ", irq);
1355		for_each_irq_pin(entry, data->irq_2_pin)
1356			pr_cont("-> %d:%d", entry->apic, entry->pin);
1357		pr_cont("\n");
1358	}
1359
1360	printk(KERN_INFO ".................................... done.\n");
1361}
1362
1363/* Where if anywhere is the i8259 connect in external int mode */
1364static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
1365
1366void __init enable_IO_APIC(void)
1367{
1368	int i8259_apic, i8259_pin;
1369	int apic, pin;
1370
1371	if (skip_ioapic_setup)
1372		nr_ioapics = 0;
1373
1374	if (!nr_legacy_irqs() || !nr_ioapics)
1375		return;
1376
1377	for_each_ioapic_pin(apic, pin) {
1378		/* See if any of the pins is in ExtINT mode */
1379		struct IO_APIC_route_entry entry = ioapic_read_entry(apic, pin);
1380
1381		/* If the interrupt line is enabled and in ExtInt mode
1382		 * I have found the pin where the i8259 is connected.
1383		 */
1384		if ((entry.mask == 0) && (entry.delivery_mode == dest_ExtINT)) {
1385			ioapic_i8259.apic = apic;
1386			ioapic_i8259.pin  = pin;
1387			goto found_i8259;
1388		}
1389	}
1390 found_i8259:
1391	/* Look to see what if the MP table has reported the ExtINT */
1392	/* If we could not find the appropriate pin by looking at the ioapic
1393	 * the i8259 probably is not connected the ioapic but give the
1394	 * mptable a chance anyway.
1395	 */
1396	i8259_pin  = find_isa_irq_pin(0, mp_ExtINT);
1397	i8259_apic = find_isa_irq_apic(0, mp_ExtINT);
1398	/* Trust the MP table if nothing is setup in the hardware */
1399	if ((ioapic_i8259.pin == -1) && (i8259_pin >= 0)) {
1400		printk(KERN_WARNING "ExtINT not setup in hardware but reported by MP table\n");
1401		ioapic_i8259.pin  = i8259_pin;
1402		ioapic_i8259.apic = i8259_apic;
1403	}
1404	/* Complain if the MP table and the hardware disagree */
1405	if (((ioapic_i8259.apic != i8259_apic) || (ioapic_i8259.pin != i8259_pin)) &&
1406		(i8259_pin >= 0) && (ioapic_i8259.pin >= 0))
1407	{
1408		printk(KERN_WARNING "ExtINT in hardware and MP table differ\n");
1409	}
1410
1411	/*
1412	 * Do not trust the IO-APIC being empty at bootup
1413	 */
1414	clear_IO_APIC();
1415}
1416
1417void native_restore_boot_irq_mode(void)
1418{
1419	/*
1420	 * If the i8259 is routed through an IOAPIC
1421	 * Put that IOAPIC in virtual wire mode
1422	 * so legacy interrupts can be delivered.
1423	 */
1424	if (ioapic_i8259.pin != -1) {
1425		struct IO_APIC_route_entry entry;
1426
1427		memset(&entry, 0, sizeof(entry));
1428		entry.mask		= IOAPIC_UNMASKED;
1429		entry.trigger		= IOAPIC_EDGE;
1430		entry.polarity		= IOAPIC_POL_HIGH;
1431		entry.dest_mode		= IOAPIC_DEST_MODE_PHYSICAL;
1432		entry.delivery_mode	= dest_ExtINT;
1433		entry.dest		= read_apic_id();
1434
1435		/*
1436		 * Add it to the IO-APIC irq-routing table:
1437		 */
1438		ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, entry);
1439	}
1440
1441	if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
1442		disconnect_bsp_APIC(ioapic_i8259.pin != -1);
1443}
1444
1445void restore_boot_irq_mode(void)
1446{
1447	if (!nr_legacy_irqs())
1448		return;
1449
1450	x86_apic_ops.restore();
1451}
1452
1453#ifdef CONFIG_X86_32
1454/*
1455 * function to set the IO-APIC physical IDs based on the
1456 * values stored in the MPC table.
1457 *
1458 * by Matt Domsch <Matt_Domsch@dell.com>  Tue Dec 21 12:25:05 CST 1999
1459 */
1460void __init setup_ioapic_ids_from_mpc_nocheck(void)
1461{
1462	union IO_APIC_reg_00 reg_00;
1463	physid_mask_t phys_id_present_map;
1464	int ioapic_idx;
1465	int i;
1466	unsigned char old_id;
1467	unsigned long flags;
1468
1469	/*
1470	 * This is broken; anything with a real cpu count has to
1471	 * circumvent this idiocy regardless.
1472	 */
1473	apic->ioapic_phys_id_map(&phys_cpu_present_map, &phys_id_present_map);
1474
1475	/*
1476	 * Set the IOAPIC ID to the value stored in the MPC table.
1477	 */
1478	for_each_ioapic(ioapic_idx) {
1479		/* Read the register 0 value */
1480		raw_spin_lock_irqsave(&ioapic_lock, flags);
1481		reg_00.raw = io_apic_read(ioapic_idx, 0);
1482		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1483
1484		old_id = mpc_ioapic_id(ioapic_idx);
1485
1486		if (mpc_ioapic_id(ioapic_idx) >= get_physical_broadcast()) {
1487			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID is %d in the MPC table!...\n",
1488				ioapic_idx, mpc_ioapic_id(ioapic_idx));
1489			printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
1490				reg_00.bits.ID);
1491			ioapics[ioapic_idx].mp_config.apicid = reg_00.bits.ID;
1492		}
1493
1494		/*
1495		 * Sanity check, is the ID really free? Every APIC in a
1496		 * system must have a unique ID or we get lots of nice
1497		 * 'stuck on smp_invalidate_needed IPI wait' messages.
1498		 */
1499		if (apic->check_apicid_used(&phys_id_present_map,
1500					    mpc_ioapic_id(ioapic_idx))) {
1501			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID %d is already used!...\n",
1502				ioapic_idx, mpc_ioapic_id(ioapic_idx));
1503			for (i = 0; i < get_physical_broadcast(); i++)
1504				if (!physid_isset(i, phys_id_present_map))
1505					break;
1506			if (i >= get_physical_broadcast())
1507				panic("Max APIC ID exceeded!\n");
1508			printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
1509				i);
1510			physid_set(i, phys_id_present_map);
1511			ioapics[ioapic_idx].mp_config.apicid = i;
1512		} else {
1513			physid_mask_t tmp;
1514			apic->apicid_to_cpu_present(mpc_ioapic_id(ioapic_idx),
1515						    &tmp);
1516			apic_printk(APIC_VERBOSE, "Setting %d in the "
1517					"phys_id_present_map\n",
1518					mpc_ioapic_id(ioapic_idx));
1519			physids_or(phys_id_present_map, phys_id_present_map, tmp);
1520		}
1521
1522		/*
1523		 * We need to adjust the IRQ routing table
1524		 * if the ID changed.
1525		 */
1526		if (old_id != mpc_ioapic_id(ioapic_idx))
1527			for (i = 0; i < mp_irq_entries; i++)
1528				if (mp_irqs[i].dstapic == old_id)
1529					mp_irqs[i].dstapic
1530						= mpc_ioapic_id(ioapic_idx);
1531
1532		/*
1533		 * Update the ID register according to the right value
1534		 * from the MPC table if they are different.
1535		 */
1536		if (mpc_ioapic_id(ioapic_idx) == reg_00.bits.ID)
1537			continue;
1538
1539		apic_printk(APIC_VERBOSE, KERN_INFO
1540			"...changing IO-APIC physical APIC ID to %d ...",
1541			mpc_ioapic_id(ioapic_idx));
1542
1543		reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
1544		raw_spin_lock_irqsave(&ioapic_lock, flags);
1545		io_apic_write(ioapic_idx, 0, reg_00.raw);
1546		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1547
1548		/*
1549		 * Sanity check
1550		 */
1551		raw_spin_lock_irqsave(&ioapic_lock, flags);
1552		reg_00.raw = io_apic_read(ioapic_idx, 0);
1553		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1554		if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx))
1555			pr_cont("could not set ID!\n");
1556		else
1557			apic_printk(APIC_VERBOSE, " ok.\n");
1558	}
1559}
1560
1561void __init setup_ioapic_ids_from_mpc(void)
1562{
1563
1564	if (acpi_ioapic)
1565		return;
1566	/*
1567	 * Don't check I/O APIC IDs for xAPIC systems.  They have
1568	 * no meaning without the serial APIC bus.
1569	 */
1570	if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
1571		|| APIC_XAPIC(boot_cpu_apic_version))
1572		return;
1573	setup_ioapic_ids_from_mpc_nocheck();
1574}
1575#endif
1576
1577int no_timer_check __initdata;
1578
1579static int __init notimercheck(char *s)
1580{
1581	no_timer_check = 1;
1582	return 1;
1583}
1584__setup("no_timer_check", notimercheck);
1585
1586static void __init delay_with_tsc(void)
1587{
1588	unsigned long long start, now;
1589	unsigned long end = jiffies + 4;
1590
1591	start = rdtsc();
1592
1593	/*
1594	 * We don't know the TSC frequency yet, but waiting for
1595	 * 40000000000/HZ TSC cycles is safe:
1596	 * 4 GHz == 10 jiffies
1597	 * 1 GHz == 40 jiffies
1598	 */
1599	do {
1600		rep_nop();
1601		now = rdtsc();
1602	} while ((now - start) < 40000000000ULL / HZ &&
1603		time_before_eq(jiffies, end));
1604}
1605
1606static void __init delay_without_tsc(void)
1607{
1608	unsigned long end = jiffies + 4;
1609	int band = 1;
1610
1611	/*
1612	 * We don't know any frequency yet, but waiting for
1613	 * 40940000000/HZ cycles is safe:
1614	 * 4 GHz == 10 jiffies
1615	 * 1 GHz == 40 jiffies
1616	 * 1 << 1 + 1 << 2 +...+ 1 << 11 = 4094
1617	 */
1618	do {
1619		__delay(((1U << band++) * 10000000UL) / HZ);
1620	} while (band < 12 && time_before_eq(jiffies, end));
1621}
1622
1623/*
1624 * There is a nasty bug in some older SMP boards, their mptable lies
1625 * about the timer IRQ. We do the following to work around the situation:
1626 *
1627 *	- timer IRQ defaults to IO-APIC IRQ
1628 *	- if this function detects that timer IRQs are defunct, then we fall
1629 *	  back to ISA timer IRQs
1630 */
1631static int __init timer_irq_works(void)
1632{
1633	unsigned long t1 = jiffies;
1634	unsigned long flags;
1635
1636	if (no_timer_check)
1637		return 1;
1638
1639	local_save_flags(flags);
1640	local_irq_enable();
1641
1642	if (boot_cpu_has(X86_FEATURE_TSC))
1643		delay_with_tsc();
1644	else
1645		delay_without_tsc();
1646
1647	local_irq_restore(flags);
1648
1649	/*
1650	 * Expect a few ticks at least, to be sure some possible
1651	 * glue logic does not lock up after one or two first
1652	 * ticks in a non-ExtINT mode.  Also the local APIC
1653	 * might have cached one ExtINT interrupt.  Finally, at
1654	 * least one tick may be lost due to delays.
1655	 */
1656
1657	/* jiffies wrap? */
1658	if (time_after(jiffies, t1 + 4))
1659		return 1;
1660	return 0;
1661}
1662
1663/*
1664 * In the SMP+IOAPIC case it might happen that there are an unspecified
1665 * number of pending IRQ events unhandled. These cases are very rare,
1666 * so we 'resend' these IRQs via IPIs, to the same CPU. It's much
1667 * better to do it this way as thus we do not have to be aware of
1668 * 'pending' interrupts in the IRQ path, except at this point.
1669 */
1670/*
1671 * Edge triggered needs to resend any interrupt
1672 * that was delayed but this is now handled in the device
1673 * independent code.
1674 */
1675
1676/*
1677 * Starting up a edge-triggered IO-APIC interrupt is
1678 * nasty - we need to make sure that we get the edge.
1679 * If it is already asserted for some reason, we need
1680 * return 1 to indicate that is was pending.
1681 *
1682 * This is not complete - we should be able to fake
1683 * an edge even if it isn't on the 8259A...
1684 */
1685static unsigned int startup_ioapic_irq(struct irq_data *data)
1686{
1687	int was_pending = 0, irq = data->irq;
1688	unsigned long flags;
1689
1690	raw_spin_lock_irqsave(&ioapic_lock, flags);
1691	if (irq < nr_legacy_irqs()) {
1692		legacy_pic->mask(irq);
1693		if (legacy_pic->irq_pending(irq))
1694			was_pending = 1;
1695	}
1696	__unmask_ioapic(data->chip_data);
1697	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1698
1699	return was_pending;
1700}
1701
1702atomic_t irq_mis_count;
1703
1704#ifdef CONFIG_GENERIC_PENDING_IRQ
1705static bool io_apic_level_ack_pending(struct mp_chip_data *data)
1706{
1707	struct irq_pin_list *entry;
1708	unsigned long flags;
1709
1710	raw_spin_lock_irqsave(&ioapic_lock, flags);
1711	for_each_irq_pin(entry, data->irq_2_pin) {
1712		unsigned int reg;
1713		int pin;
1714
1715		pin = entry->pin;
1716		reg = io_apic_read(entry->apic, 0x10 + pin*2);
1717		/* Is the remote IRR bit set? */
1718		if (reg & IO_APIC_REDIR_REMOTE_IRR) {
1719			raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1720			return true;
1721		}
1722	}
1723	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1724
1725	return false;
1726}
1727
1728static inline bool ioapic_irqd_mask(struct irq_data *data)
1729{
1730	/* If we are moving the irq we need to mask it */
1731	if (unlikely(irqd_is_setaffinity_pending(data))) {
1732		mask_ioapic_irq(data);
 
1733		return true;
1734	}
1735	return false;
1736}
1737
1738static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked)
1739{
1740	if (unlikely(masked)) {
1741		/* Only migrate the irq if the ack has been received.
1742		 *
1743		 * On rare occasions the broadcast level triggered ack gets
1744		 * delayed going to ioapics, and if we reprogram the
1745		 * vector while Remote IRR is still set the irq will never
1746		 * fire again.
1747		 *
1748		 * To prevent this scenario we read the Remote IRR bit
1749		 * of the ioapic.  This has two effects.
1750		 * - On any sane system the read of the ioapic will
1751		 *   flush writes (and acks) going to the ioapic from
1752		 *   this cpu.
1753		 * - We get to see if the ACK has actually been delivered.
1754		 *
1755		 * Based on failed experiments of reprogramming the
1756		 * ioapic entry from outside of irq context starting
1757		 * with masking the ioapic entry and then polling until
1758		 * Remote IRR was clear before reprogramming the
1759		 * ioapic I don't trust the Remote IRR bit to be
1760		 * completey accurate.
1761		 *
1762		 * However there appears to be no other way to plug
1763		 * this race, so if the Remote IRR bit is not
1764		 * accurate and is causing problems then it is a hardware bug
1765		 * and you can go talk to the chipset vendor about it.
1766		 */
1767		if (!io_apic_level_ack_pending(data->chip_data))
1768			irq_move_masked_irq(data);
1769		unmask_ioapic_irq(data);
 
 
1770	}
1771}
1772#else
1773static inline bool ioapic_irqd_mask(struct irq_data *data)
1774{
1775	return false;
1776}
1777static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked)
1778{
1779}
1780#endif
1781
1782static void ioapic_ack_level(struct irq_data *irq_data)
1783{
1784	struct irq_cfg *cfg = irqd_cfg(irq_data);
1785	unsigned long v;
1786	bool masked;
1787	int i;
1788
1789	irq_complete_move(cfg);
1790	masked = ioapic_irqd_mask(irq_data);
1791
1792	/*
1793	 * It appears there is an erratum which affects at least version 0x11
1794	 * of I/O APIC (that's the 82093AA and cores integrated into various
1795	 * chipsets).  Under certain conditions a level-triggered interrupt is
1796	 * erroneously delivered as edge-triggered one but the respective IRR
1797	 * bit gets set nevertheless.  As a result the I/O unit expects an EOI
1798	 * message but it will never arrive and further interrupts are blocked
1799	 * from the source.  The exact reason is so far unknown, but the
1800	 * phenomenon was observed when two consecutive interrupt requests
1801	 * from a given source get delivered to the same CPU and the source is
1802	 * temporarily disabled in between.
1803	 *
1804	 * A workaround is to simulate an EOI message manually.  We achieve it
1805	 * by setting the trigger mode to edge and then to level when the edge
1806	 * trigger mode gets detected in the TMR of a local APIC for a
1807	 * level-triggered interrupt.  We mask the source for the time of the
1808	 * operation to prevent an edge-triggered interrupt escaping meanwhile.
1809	 * The idea is from Manfred Spraul.  --macro
1810	 *
1811	 * Also in the case when cpu goes offline, fixup_irqs() will forward
1812	 * any unhandled interrupt on the offlined cpu to the new cpu
1813	 * destination that is handling the corresponding interrupt. This
1814	 * interrupt forwarding is done via IPI's. Hence, in this case also
1815	 * level-triggered io-apic interrupt will be seen as an edge
1816	 * interrupt in the IRR. And we can't rely on the cpu's EOI
1817	 * to be broadcasted to the IO-APIC's which will clear the remoteIRR
1818	 * corresponding to the level-triggered interrupt. Hence on IO-APIC's
1819	 * supporting EOI register, we do an explicit EOI to clear the
1820	 * remote IRR and on IO-APIC's which don't have an EOI register,
1821	 * we use the above logic (mask+edge followed by unmask+level) from
1822	 * Manfred Spraul to clear the remote IRR.
1823	 */
1824	i = cfg->vector;
1825	v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
1826
1827	/*
1828	 * We must acknowledge the irq before we move it or the acknowledge will
1829	 * not propagate properly.
1830	 */
1831	ack_APIC_irq();
1832
1833	/*
1834	 * Tail end of clearing remote IRR bit (either by delivering the EOI
1835	 * message via io-apic EOI register write or simulating it using
1836	 * mask+edge followed by unnask+level logic) manually when the
1837	 * level triggered interrupt is seen as the edge triggered interrupt
1838	 * at the cpu.
1839	 */
1840	if (!(v & (1 << (i & 0x1f)))) {
1841		atomic_inc(&irq_mis_count);
1842		eoi_ioapic_pin(cfg->vector, irq_data->chip_data);
1843	}
1844
1845	ioapic_irqd_unmask(irq_data, masked);
1846}
1847
1848static void ioapic_ir_ack_level(struct irq_data *irq_data)
1849{
1850	struct mp_chip_data *data = irq_data->chip_data;
1851
1852	/*
1853	 * Intr-remapping uses pin number as the virtual vector
1854	 * in the RTE. Actual vector is programmed in
1855	 * intr-remapping table entry. Hence for the io-apic
1856	 * EOI we use the pin number.
1857	 */
1858	apic_ack_irq(irq_data);
1859	eoi_ioapic_pin(data->entry.vector, data);
1860}
1861
1862static void ioapic_configure_entry(struct irq_data *irqd)
1863{
1864	struct mp_chip_data *mpd = irqd->chip_data;
1865	struct irq_cfg *cfg = irqd_cfg(irqd);
1866	struct irq_pin_list *entry;
1867
1868	/*
1869	 * Only update when the parent is the vector domain, don't touch it
1870	 * if the parent is the remapping domain. Check the installed
1871	 * ioapic chip to verify that.
1872	 */
1873	if (irqd->chip == &ioapic_chip) {
1874		mpd->entry.dest = cfg->dest_apicid;
1875		mpd->entry.vector = cfg->vector;
1876	}
1877	for_each_irq_pin(entry, mpd->irq_2_pin)
1878		__ioapic_write_entry(entry->apic, entry->pin, mpd->entry);
1879}
1880
1881static int ioapic_set_affinity(struct irq_data *irq_data,
1882			       const struct cpumask *mask, bool force)
1883{
1884	struct irq_data *parent = irq_data->parent_data;
1885	unsigned long flags;
1886	int ret;
1887
1888	ret = parent->chip->irq_set_affinity(parent, mask, force);
1889	raw_spin_lock_irqsave(&ioapic_lock, flags);
1890	if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE)
1891		ioapic_configure_entry(irq_data);
1892	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1893
1894	return ret;
1895}
1896
1897/*
1898 * Interrupt shutdown masks the ioapic pin, but the interrupt might already
1899 * be in flight, but not yet serviced by the target CPU. That means
1900 * __synchronize_hardirq() would return and claim that everything is calmed
1901 * down. So free_irq() would proceed and deactivate the interrupt and free
1902 * resources.
1903 *
1904 * Once the target CPU comes around to service it it will find a cleared
1905 * vector and complain. While the spurious interrupt is harmless, the full
1906 * release of resources might prevent the interrupt from being acknowledged
1907 * which keeps the hardware in a weird state.
1908 *
1909 * Verify that the corresponding Remote-IRR bits are clear.
1910 */
1911static int ioapic_irq_get_chip_state(struct irq_data *irqd,
1912				   enum irqchip_irq_state which,
1913				   bool *state)
1914{
1915	struct mp_chip_data *mcd = irqd->chip_data;
1916	struct IO_APIC_route_entry rentry;
1917	struct irq_pin_list *p;
1918
1919	if (which != IRQCHIP_STATE_ACTIVE)
1920		return -EINVAL;
1921
1922	*state = false;
1923	raw_spin_lock(&ioapic_lock);
1924	for_each_irq_pin(p, mcd->irq_2_pin) {
1925		rentry = __ioapic_read_entry(p->apic, p->pin);
1926		/*
1927		 * The remote IRR is only valid in level trigger mode. It's
1928		 * meaning is undefined for edge triggered interrupts and
1929		 * irrelevant because the IO-APIC treats them as fire and
1930		 * forget.
1931		 */
1932		if (rentry.irr && rentry.trigger) {
1933			*state = true;
1934			break;
1935		}
1936	}
1937	raw_spin_unlock(&ioapic_lock);
1938	return 0;
1939}
1940
1941static struct irq_chip ioapic_chip __read_mostly = {
1942	.name			= "IO-APIC",
1943	.irq_startup		= startup_ioapic_irq,
1944	.irq_mask		= mask_ioapic_irq,
1945	.irq_unmask		= unmask_ioapic_irq,
1946	.irq_ack		= irq_chip_ack_parent,
1947	.irq_eoi		= ioapic_ack_level,
1948	.irq_set_affinity	= ioapic_set_affinity,
1949	.irq_retrigger		= irq_chip_retrigger_hierarchy,
1950	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
1951	.flags			= IRQCHIP_SKIP_SET_WAKE,
1952};
1953
1954static struct irq_chip ioapic_ir_chip __read_mostly = {
1955	.name			= "IR-IO-APIC",
1956	.irq_startup		= startup_ioapic_irq,
1957	.irq_mask		= mask_ioapic_irq,
1958	.irq_unmask		= unmask_ioapic_irq,
1959	.irq_ack		= irq_chip_ack_parent,
1960	.irq_eoi		= ioapic_ir_ack_level,
1961	.irq_set_affinity	= ioapic_set_affinity,
1962	.irq_retrigger		= irq_chip_retrigger_hierarchy,
1963	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
1964	.flags			= IRQCHIP_SKIP_SET_WAKE,
1965};
1966
1967static inline void init_IO_APIC_traps(void)
1968{
1969	struct irq_cfg *cfg;
1970	unsigned int irq;
1971
1972	for_each_active_irq(irq) {
1973		cfg = irq_cfg(irq);
1974		if (IO_APIC_IRQ(irq) && cfg && !cfg->vector) {
1975			/*
1976			 * Hmm.. We don't have an entry for this,
1977			 * so default to an old-fashioned 8259
1978			 * interrupt if we can..
1979			 */
1980			if (irq < nr_legacy_irqs())
1981				legacy_pic->make_irq(irq);
1982			else
1983				/* Strange. Oh, well.. */
1984				irq_set_chip(irq, &no_irq_chip);
1985		}
1986	}
1987}
1988
1989/*
1990 * The local APIC irq-chip implementation:
1991 */
1992
1993static void mask_lapic_irq(struct irq_data *data)
1994{
1995	unsigned long v;
1996
1997	v = apic_read(APIC_LVT0);
1998	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1999}
2000
2001static void unmask_lapic_irq(struct irq_data *data)
2002{
2003	unsigned long v;
2004
2005	v = apic_read(APIC_LVT0);
2006	apic_write(APIC_LVT0, v & ~APIC_LVT_MASKED);
2007}
2008
2009static void ack_lapic_irq(struct irq_data *data)
2010{
2011	ack_APIC_irq();
2012}
2013
2014static struct irq_chip lapic_chip __read_mostly = {
2015	.name		= "local-APIC",
2016	.irq_mask	= mask_lapic_irq,
2017	.irq_unmask	= unmask_lapic_irq,
2018	.irq_ack	= ack_lapic_irq,
2019};
2020
2021static void lapic_register_intr(int irq)
2022{
2023	irq_clear_status_flags(irq, IRQ_LEVEL);
2024	irq_set_chip_and_handler_name(irq, &lapic_chip, handle_edge_irq,
2025				      "edge");
2026}
2027
2028/*
2029 * This looks a bit hackish but it's about the only one way of sending
2030 * a few INTA cycles to 8259As and any associated glue logic.  ICR does
2031 * not support the ExtINT mode, unfortunately.  We need to send these
2032 * cycles as some i82489DX-based boards have glue logic that keeps the
2033 * 8259A interrupt line asserted until INTA.  --macro
2034 */
2035static inline void __init unlock_ExtINT_logic(void)
2036{
2037	int apic, pin, i;
2038	struct IO_APIC_route_entry entry0, entry1;
2039	unsigned char save_control, save_freq_select;
2040
2041	pin  = find_isa_irq_pin(8, mp_INT);
2042	if (pin == -1) {
2043		WARN_ON_ONCE(1);
2044		return;
2045	}
2046	apic = find_isa_irq_apic(8, mp_INT);
2047	if (apic == -1) {
2048		WARN_ON_ONCE(1);
2049		return;
2050	}
2051
2052	entry0 = ioapic_read_entry(apic, pin);
2053	clear_IO_APIC_pin(apic, pin);
2054
2055	memset(&entry1, 0, sizeof(entry1));
2056
2057	entry1.dest_mode = IOAPIC_DEST_MODE_PHYSICAL;
2058	entry1.mask = IOAPIC_UNMASKED;
2059	entry1.dest = hard_smp_processor_id();
2060	entry1.delivery_mode = dest_ExtINT;
2061	entry1.polarity = entry0.polarity;
2062	entry1.trigger = IOAPIC_EDGE;
2063	entry1.vector = 0;
2064
2065	ioapic_write_entry(apic, pin, entry1);
2066
2067	save_control = CMOS_READ(RTC_CONTROL);
2068	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
2069	CMOS_WRITE((save_freq_select & ~RTC_RATE_SELECT) | 0x6,
2070		   RTC_FREQ_SELECT);
2071	CMOS_WRITE(save_control | RTC_PIE, RTC_CONTROL);
2072
2073	i = 100;
2074	while (i-- > 0) {
2075		mdelay(10);
2076		if ((CMOS_READ(RTC_INTR_FLAGS) & RTC_PF) == RTC_PF)
2077			i -= 10;
2078	}
2079
2080	CMOS_WRITE(save_control, RTC_CONTROL);
2081	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
2082	clear_IO_APIC_pin(apic, pin);
2083
2084	ioapic_write_entry(apic, pin, entry0);
2085}
2086
2087static int disable_timer_pin_1 __initdata;
2088/* Actually the next is obsolete, but keep it for paranoid reasons -AK */
2089static int __init disable_timer_pin_setup(char *arg)
2090{
2091	disable_timer_pin_1 = 1;
2092	return 0;
2093}
2094early_param("disable_timer_pin_1", disable_timer_pin_setup);
2095
2096static int mp_alloc_timer_irq(int ioapic, int pin)
2097{
2098	int irq = -1;
2099	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
2100
2101	if (domain) {
2102		struct irq_alloc_info info;
2103
2104		ioapic_set_alloc_attr(&info, NUMA_NO_NODE, 0, 0);
2105		info.ioapic_id = mpc_ioapic_id(ioapic);
2106		info.ioapic_pin = pin;
2107		mutex_lock(&ioapic_mutex);
2108		irq = alloc_isa_irq_from_domain(domain, 0, ioapic, pin, &info);
2109		mutex_unlock(&ioapic_mutex);
2110	}
2111
2112	return irq;
2113}
2114
2115/*
2116 * This code may look a bit paranoid, but it's supposed to cooperate with
2117 * a wide range of boards and BIOS bugs.  Fortunately only the timer IRQ
2118 * is so screwy.  Thanks to Brian Perkins for testing/hacking this beast
2119 * fanatically on his truly buggy board.
2120 *
2121 * FIXME: really need to revamp this for all platforms.
2122 */
2123static inline void __init check_timer(void)
2124{
2125	struct irq_data *irq_data = irq_get_irq_data(0);
2126	struct mp_chip_data *data = irq_data->chip_data;
2127	struct irq_cfg *cfg = irqd_cfg(irq_data);
2128	int node = cpu_to_node(0);
2129	int apic1, pin1, apic2, pin2;
2130	unsigned long flags;
2131	int no_pin1 = 0;
2132
2133	if (!global_clock_event)
2134		return;
2135
2136	local_irq_save(flags);
2137
2138	/*
2139	 * get/set the timer IRQ vector:
2140	 */
2141	legacy_pic->mask(0);
2142
2143	/*
2144	 * As IRQ0 is to be enabled in the 8259A, the virtual
2145	 * wire has to be disabled in the local APIC.  Also
2146	 * timer interrupts need to be acknowledged manually in
2147	 * the 8259A for the i82489DX when using the NMI
2148	 * watchdog as that APIC treats NMIs as level-triggered.
2149	 * The AEOI mode will finish them in the 8259A
2150	 * automatically.
2151	 */
2152	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
2153	legacy_pic->init(1);
2154
2155	pin1  = find_isa_irq_pin(0, mp_INT);
2156	apic1 = find_isa_irq_apic(0, mp_INT);
2157	pin2  = ioapic_i8259.pin;
2158	apic2 = ioapic_i8259.apic;
2159
2160	apic_printk(APIC_QUIET, KERN_INFO "..TIMER: vector=0x%02X "
2161		    "apic1=%d pin1=%d apic2=%d pin2=%d\n",
2162		    cfg->vector, apic1, pin1, apic2, pin2);
2163
2164	/*
2165	 * Some BIOS writers are clueless and report the ExtINTA
2166	 * I/O APIC input from the cascaded 8259A as the timer
2167	 * interrupt input.  So just in case, if only one pin
2168	 * was found above, try it both directly and through the
2169	 * 8259A.
2170	 */
2171	if (pin1 == -1) {
2172		panic_if_irq_remap("BIOS bug: timer not connected to IO-APIC");
2173		pin1 = pin2;
2174		apic1 = apic2;
2175		no_pin1 = 1;
2176	} else if (pin2 == -1) {
2177		pin2 = pin1;
2178		apic2 = apic1;
2179	}
2180
2181	if (pin1 != -1) {
2182		/* Ok, does IRQ0 through the IOAPIC work? */
2183		if (no_pin1) {
2184			mp_alloc_timer_irq(apic1, pin1);
2185		} else {
2186			/*
2187			 * for edge trigger, it's already unmasked,
2188			 * so only need to unmask if it is level-trigger
2189			 * do we really have level trigger timer?
2190			 */
2191			int idx;
2192			idx = find_irq_entry(apic1, pin1, mp_INT);
2193			if (idx != -1 && irq_trigger(idx))
2194				unmask_ioapic_irq(irq_get_irq_data(0));
2195		}
2196		irq_domain_deactivate_irq(irq_data);
2197		irq_domain_activate_irq(irq_data, false);
2198		if (timer_irq_works()) {
2199			if (disable_timer_pin_1 > 0)
2200				clear_IO_APIC_pin(0, pin1);
2201			goto out;
2202		}
2203		panic_if_irq_remap("timer doesn't work through Interrupt-remapped IO-APIC");
2204		local_irq_disable();
2205		clear_IO_APIC_pin(apic1, pin1);
2206		if (!no_pin1)
2207			apic_printk(APIC_QUIET, KERN_ERR "..MP-BIOS bug: "
2208				    "8254 timer not connected to IO-APIC\n");
2209
2210		apic_printk(APIC_QUIET, KERN_INFO "...trying to set up timer "
2211			    "(IRQ0) through the 8259A ...\n");
2212		apic_printk(APIC_QUIET, KERN_INFO
2213			    "..... (found apic %d pin %d) ...\n", apic2, pin2);
2214		/*
2215		 * legacy devices should be connected to IO APIC #0
2216		 */
2217		replace_pin_at_irq_node(data, node, apic1, pin1, apic2, pin2);
2218		irq_domain_deactivate_irq(irq_data);
2219		irq_domain_activate_irq(irq_data, false);
2220		legacy_pic->unmask(0);
2221		if (timer_irq_works()) {
2222			apic_printk(APIC_QUIET, KERN_INFO "....... works.\n");
2223			goto out;
2224		}
2225		/*
2226		 * Cleanup, just in case ...
2227		 */
2228		local_irq_disable();
2229		legacy_pic->mask(0);
2230		clear_IO_APIC_pin(apic2, pin2);
2231		apic_printk(APIC_QUIET, KERN_INFO "....... failed.\n");
2232	}
2233
2234	apic_printk(APIC_QUIET, KERN_INFO
2235		    "...trying to set up timer as Virtual Wire IRQ...\n");
2236
2237	lapic_register_intr(0);
2238	apic_write(APIC_LVT0, APIC_DM_FIXED | cfg->vector);	/* Fixed mode */
2239	legacy_pic->unmask(0);
2240
2241	if (timer_irq_works()) {
2242		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
2243		goto out;
2244	}
2245	local_irq_disable();
2246	legacy_pic->mask(0);
2247	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | cfg->vector);
2248	apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");
2249
2250	apic_printk(APIC_QUIET, KERN_INFO
2251		    "...trying to set up timer as ExtINT IRQ...\n");
2252
2253	legacy_pic->init(0);
2254	legacy_pic->make_irq(0);
2255	apic_write(APIC_LVT0, APIC_DM_EXTINT);
 
2256
2257	unlock_ExtINT_logic();
2258
2259	if (timer_irq_works()) {
2260		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
2261		goto out;
2262	}
2263	local_irq_disable();
2264	apic_printk(APIC_QUIET, KERN_INFO "..... failed :(.\n");
2265	if (apic_is_x2apic_enabled())
2266		apic_printk(APIC_QUIET, KERN_INFO
2267			    "Perhaps problem with the pre-enabled x2apic mode\n"
2268			    "Try booting with x2apic and interrupt-remapping disabled in the bios.\n");
2269	panic("IO-APIC + timer doesn't work!  Boot with apic=debug and send a "
2270		"report.  Then try booting with the 'noapic' option.\n");
2271out:
2272	local_irq_restore(flags);
2273}
2274
2275/*
2276 * Traditionally ISA IRQ2 is the cascade IRQ, and is not available
2277 * to devices.  However there may be an I/O APIC pin available for
2278 * this interrupt regardless.  The pin may be left unconnected, but
2279 * typically it will be reused as an ExtINT cascade interrupt for
2280 * the master 8259A.  In the MPS case such a pin will normally be
2281 * reported as an ExtINT interrupt in the MP table.  With ACPI
2282 * there is no provision for ExtINT interrupts, and in the absence
2283 * of an override it would be treated as an ordinary ISA I/O APIC
2284 * interrupt, that is edge-triggered and unmasked by default.  We
2285 * used to do this, but it caused problems on some systems because
2286 * of the NMI watchdog and sometimes IRQ0 of the 8254 timer using
2287 * the same ExtINT cascade interrupt to drive the local APIC of the
2288 * bootstrap processor.  Therefore we refrain from routing IRQ2 to
2289 * the I/O APIC in all cases now.  No actual device should request
2290 * it anyway.  --macro
2291 */
2292#define PIC_IRQS	(1UL << PIC_CASCADE_IR)
2293
2294static int mp_irqdomain_create(int ioapic)
2295{
2296	struct irq_alloc_info info;
2297	struct irq_domain *parent;
2298	int hwirqs = mp_ioapic_pin_count(ioapic);
2299	struct ioapic *ip = &ioapics[ioapic];
2300	struct ioapic_domain_cfg *cfg = &ip->irqdomain_cfg;
2301	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic);
2302	struct fwnode_handle *fn;
2303	char *name = "IO-APIC";
2304
2305	if (cfg->type == IOAPIC_DOMAIN_INVALID)
2306		return 0;
2307
2308	init_irq_alloc_info(&info, NULL);
2309	info.type = X86_IRQ_ALLOC_TYPE_IOAPIC;
2310	info.ioapic_id = mpc_ioapic_id(ioapic);
2311	parent = irq_remapping_get_ir_irq_domain(&info);
2312	if (!parent)
2313		parent = x86_vector_domain;
2314	else
2315		name = "IO-APIC-IR";
2316
2317	/* Handle device tree enumerated APICs proper */
2318	if (cfg->dev) {
2319		fn = of_node_to_fwnode(cfg->dev);
2320	} else {
2321		fn = irq_domain_alloc_named_id_fwnode(name, ioapic);
2322		if (!fn)
2323			return -ENOMEM;
2324	}
2325
2326	ip->irqdomain = irq_domain_create_linear(fn, hwirqs, cfg->ops,
2327						 (void *)(long)ioapic);
2328
2329	/* Release fw handle if it was allocated above */
2330	if (!cfg->dev)
2331		irq_domain_free_fwnode(fn);
2332
2333	if (!ip->irqdomain)
2334		return -ENOMEM;
 
2335
2336	ip->irqdomain->parent = parent;
2337
2338	if (cfg->type == IOAPIC_DOMAIN_LEGACY ||
2339	    cfg->type == IOAPIC_DOMAIN_STRICT)
2340		ioapic_dynirq_base = max(ioapic_dynirq_base,
2341					 gsi_cfg->gsi_end + 1);
2342
2343	return 0;
2344}
2345
2346static void ioapic_destroy_irqdomain(int idx)
2347{
 
 
 
2348	if (ioapics[idx].irqdomain) {
2349		irq_domain_remove(ioapics[idx].irqdomain);
 
 
2350		ioapics[idx].irqdomain = NULL;
2351	}
2352}
2353
2354void __init setup_IO_APIC(void)
2355{
2356	int ioapic;
2357
2358	if (skip_ioapic_setup || !nr_ioapics)
2359		return;
2360
2361	io_apic_irqs = nr_legacy_irqs() ? ~PIC_IRQS : ~0UL;
2362
2363	apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
2364	for_each_ioapic(ioapic)
2365		BUG_ON(mp_irqdomain_create(ioapic));
2366
2367	/*
2368         * Set up IO-APIC IRQ routing.
2369         */
2370	x86_init.mpparse.setup_ioapic_ids();
2371
2372	sync_Arb_IDs();
2373	setup_IO_APIC_irqs();
2374	init_IO_APIC_traps();
2375	if (nr_legacy_irqs())
2376		check_timer();
2377
2378	ioapic_initialized = 1;
2379}
2380
2381static void resume_ioapic_id(int ioapic_idx)
2382{
2383	unsigned long flags;
2384	union IO_APIC_reg_00 reg_00;
2385
2386	raw_spin_lock_irqsave(&ioapic_lock, flags);
2387	reg_00.raw = io_apic_read(ioapic_idx, 0);
2388	if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx)) {
2389		reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
2390		io_apic_write(ioapic_idx, 0, reg_00.raw);
2391	}
2392	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2393}
2394
2395static void ioapic_resume(void)
2396{
2397	int ioapic_idx;
2398
2399	for_each_ioapic_reverse(ioapic_idx)
2400		resume_ioapic_id(ioapic_idx);
2401
2402	restore_ioapic_entries();
2403}
2404
2405static struct syscore_ops ioapic_syscore_ops = {
2406	.suspend = save_ioapic_entries,
2407	.resume = ioapic_resume,
2408};
2409
2410static int __init ioapic_init_ops(void)
2411{
2412	register_syscore_ops(&ioapic_syscore_ops);
2413
2414	return 0;
2415}
2416
2417device_initcall(ioapic_init_ops);
2418
2419static int io_apic_get_redir_entries(int ioapic)
2420{
2421	union IO_APIC_reg_01	reg_01;
2422	unsigned long flags;
2423
2424	raw_spin_lock_irqsave(&ioapic_lock, flags);
2425	reg_01.raw = io_apic_read(ioapic, 1);
2426	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2427
2428	/* The register returns the maximum index redir index
2429	 * supported, which is one less than the total number of redir
2430	 * entries.
2431	 */
2432	return reg_01.bits.entries + 1;
2433}
2434
2435unsigned int arch_dynirq_lower_bound(unsigned int from)
2436{
2437	/*
2438	 * dmar_alloc_hwirq() may be called before setup_IO_APIC(), so use
2439	 * gsi_top if ioapic_dynirq_base hasn't been initialized yet.
2440	 */
2441	if (!ioapic_initialized)
2442		return gsi_top;
2443	/*
2444	 * For DT enabled machines ioapic_dynirq_base is irrelevant and not
2445	 * updated. So simply return @from if ioapic_dynirq_base == 0.
2446	 */
2447	return ioapic_dynirq_base ? : from;
2448}
2449
2450#ifdef CONFIG_X86_32
2451static int io_apic_get_unique_id(int ioapic, int apic_id)
2452{
2453	union IO_APIC_reg_00 reg_00;
2454	static physid_mask_t apic_id_map = PHYSID_MASK_NONE;
2455	physid_mask_t tmp;
2456	unsigned long flags;
2457	int i = 0;
2458
2459	/*
2460	 * The P4 platform supports up to 256 APIC IDs on two separate APIC
2461	 * buses (one for LAPICs, one for IOAPICs), where predecessors only
2462	 * supports up to 16 on one shared APIC bus.
2463	 *
2464	 * TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full
2465	 *      advantage of new APIC bus architecture.
2466	 */
2467
2468	if (physids_empty(apic_id_map))
2469		apic->ioapic_phys_id_map(&phys_cpu_present_map, &apic_id_map);
2470
2471	raw_spin_lock_irqsave(&ioapic_lock, flags);
2472	reg_00.raw = io_apic_read(ioapic, 0);
2473	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2474
2475	if (apic_id >= get_physical_broadcast()) {
2476		printk(KERN_WARNING "IOAPIC[%d]: Invalid apic_id %d, trying "
2477			"%d\n", ioapic, apic_id, reg_00.bits.ID);
2478		apic_id = reg_00.bits.ID;
2479	}
2480
2481	/*
2482	 * Every APIC in a system must have a unique ID or we get lots of nice
2483	 * 'stuck on smp_invalidate_needed IPI wait' messages.
2484	 */
2485	if (apic->check_apicid_used(&apic_id_map, apic_id)) {
2486
2487		for (i = 0; i < get_physical_broadcast(); i++) {
2488			if (!apic->check_apicid_used(&apic_id_map, i))
2489				break;
2490		}
2491
2492		if (i == get_physical_broadcast())
2493			panic("Max apic_id exceeded!\n");
2494
2495		printk(KERN_WARNING "IOAPIC[%d]: apic_id %d already used, "
2496			"trying %d\n", ioapic, apic_id, i);
2497
2498		apic_id = i;
2499	}
2500
2501	apic->apicid_to_cpu_present(apic_id, &tmp);
2502	physids_or(apic_id_map, apic_id_map, tmp);
2503
2504	if (reg_00.bits.ID != apic_id) {
2505		reg_00.bits.ID = apic_id;
2506
2507		raw_spin_lock_irqsave(&ioapic_lock, flags);
2508		io_apic_write(ioapic, 0, reg_00.raw);
2509		reg_00.raw = io_apic_read(ioapic, 0);
2510		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2511
2512		/* Sanity check */
2513		if (reg_00.bits.ID != apic_id) {
2514			pr_err("IOAPIC[%d]: Unable to change apic_id!\n",
2515			       ioapic);
2516			return -1;
2517		}
2518	}
2519
2520	apic_printk(APIC_VERBOSE, KERN_INFO
2521			"IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id);
2522
2523	return apic_id;
2524}
2525
2526static u8 io_apic_unique_id(int idx, u8 id)
2527{
2528	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
2529	    !APIC_XAPIC(boot_cpu_apic_version))
2530		return io_apic_get_unique_id(idx, id);
2531	else
2532		return id;
2533}
2534#else
2535static u8 io_apic_unique_id(int idx, u8 id)
2536{
2537	union IO_APIC_reg_00 reg_00;
2538	DECLARE_BITMAP(used, 256);
2539	unsigned long flags;
2540	u8 new_id;
2541	int i;
2542
2543	bitmap_zero(used, 256);
2544	for_each_ioapic(i)
2545		__set_bit(mpc_ioapic_id(i), used);
2546
2547	/* Hand out the requested id if available */
2548	if (!test_bit(id, used))
2549		return id;
2550
2551	/*
2552	 * Read the current id from the ioapic and keep it if
2553	 * available.
2554	 */
2555	raw_spin_lock_irqsave(&ioapic_lock, flags);
2556	reg_00.raw = io_apic_read(idx, 0);
2557	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2558	new_id = reg_00.bits.ID;
2559	if (!test_bit(new_id, used)) {
2560		apic_printk(APIC_VERBOSE, KERN_INFO
2561			"IOAPIC[%d]: Using reg apic_id %d instead of %d\n",
2562			 idx, new_id, id);
2563		return new_id;
2564	}
2565
2566	/*
2567	 * Get the next free id and write it to the ioapic.
2568	 */
2569	new_id = find_first_zero_bit(used, 256);
2570	reg_00.bits.ID = new_id;
2571	raw_spin_lock_irqsave(&ioapic_lock, flags);
2572	io_apic_write(idx, 0, reg_00.raw);
2573	reg_00.raw = io_apic_read(idx, 0);
2574	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2575	/* Sanity check */
2576	BUG_ON(reg_00.bits.ID != new_id);
2577
2578	return new_id;
2579}
2580#endif
2581
2582static int io_apic_get_version(int ioapic)
2583{
2584	union IO_APIC_reg_01	reg_01;
2585	unsigned long flags;
2586
2587	raw_spin_lock_irqsave(&ioapic_lock, flags);
2588	reg_01.raw = io_apic_read(ioapic, 1);
2589	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2590
2591	return reg_01.bits.version;
2592}
2593
2594int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity)
2595{
2596	int ioapic, pin, idx;
2597
2598	if (skip_ioapic_setup)
2599		return -1;
2600
2601	ioapic = mp_find_ioapic(gsi);
2602	if (ioapic < 0)
2603		return -1;
2604
2605	pin = mp_find_ioapic_pin(ioapic, gsi);
2606	if (pin < 0)
2607		return -1;
2608
2609	idx = find_irq_entry(ioapic, pin, mp_INT);
2610	if (idx < 0)
2611		return -1;
2612
2613	*trigger = irq_trigger(idx);
2614	*polarity = irq_polarity(idx);
2615	return 0;
2616}
2617
2618/*
2619 * This function updates target affinity of IOAPIC interrupts to include
2620 * the CPUs which came online during SMP bringup.
2621 */
2622#define IOAPIC_RESOURCE_NAME_SIZE 11
2623
2624static struct resource *ioapic_resources;
2625
2626static struct resource * __init ioapic_setup_resources(void)
2627{
2628	unsigned long n;
2629	struct resource *res;
2630	char *mem;
2631	int i;
2632
2633	if (nr_ioapics == 0)
2634		return NULL;
2635
2636	n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
2637	n *= nr_ioapics;
2638
2639	mem = memblock_alloc(n, SMP_CACHE_BYTES);
2640	if (!mem)
2641		panic("%s: Failed to allocate %lu bytes\n", __func__, n);
2642	res = (void *)mem;
2643
2644	mem += sizeof(struct resource) * nr_ioapics;
2645
2646	for_each_ioapic(i) {
2647		res[i].name = mem;
2648		res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
2649		snprintf(mem, IOAPIC_RESOURCE_NAME_SIZE, "IOAPIC %u", i);
2650		mem += IOAPIC_RESOURCE_NAME_SIZE;
2651		ioapics[i].iomem_res = &res[i];
2652	}
2653
2654	ioapic_resources = res;
2655
2656	return res;
2657}
2658
2659void __init io_apic_init_mappings(void)
2660{
2661	unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
2662	struct resource *ioapic_res;
2663	int i;
2664
2665	ioapic_res = ioapic_setup_resources();
2666	for_each_ioapic(i) {
2667		if (smp_found_config) {
2668			ioapic_phys = mpc_ioapic_addr(i);
2669#ifdef CONFIG_X86_32
2670			if (!ioapic_phys) {
2671				printk(KERN_ERR
2672				       "WARNING: bogus zero IO-APIC "
2673				       "address found in MPTABLE, "
2674				       "disabling IO/APIC support!\n");
2675				smp_found_config = 0;
2676				skip_ioapic_setup = 1;
2677				goto fake_ioapic_page;
2678			}
2679#endif
2680		} else {
2681#ifdef CONFIG_X86_32
2682fake_ioapic_page:
2683#endif
2684			ioapic_phys = (unsigned long)memblock_alloc(PAGE_SIZE,
2685								    PAGE_SIZE);
2686			if (!ioapic_phys)
2687				panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
2688				      __func__, PAGE_SIZE, PAGE_SIZE);
2689			ioapic_phys = __pa(ioapic_phys);
2690		}
2691		set_fixmap_nocache(idx, ioapic_phys);
2692		apic_printk(APIC_VERBOSE, "mapped IOAPIC to %08lx (%08lx)\n",
2693			__fix_to_virt(idx) + (ioapic_phys & ~PAGE_MASK),
2694			ioapic_phys);
2695		idx++;
2696
2697		ioapic_res->start = ioapic_phys;
2698		ioapic_res->end = ioapic_phys + IO_APIC_SLOT_SIZE - 1;
2699		ioapic_res++;
2700	}
2701}
2702
2703void __init ioapic_insert_resources(void)
2704{
2705	int i;
2706	struct resource *r = ioapic_resources;
2707
2708	if (!r) {
2709		if (nr_ioapics > 0)
2710			printk(KERN_ERR
2711				"IO APIC resources couldn't be allocated.\n");
2712		return;
2713	}
2714
2715	for_each_ioapic(i) {
2716		insert_resource(&iomem_resource, r);
2717		r++;
2718	}
2719}
2720
2721int mp_find_ioapic(u32 gsi)
2722{
2723	int i;
2724
2725	if (nr_ioapics == 0)
2726		return -1;
2727
2728	/* Find the IOAPIC that manages this GSI. */
2729	for_each_ioapic(i) {
2730		struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(i);
2731		if (gsi >= gsi_cfg->gsi_base && gsi <= gsi_cfg->gsi_end)
2732			return i;
2733	}
2734
2735	printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
2736	return -1;
2737}
2738
2739int mp_find_ioapic_pin(int ioapic, u32 gsi)
2740{
2741	struct mp_ioapic_gsi *gsi_cfg;
2742
2743	if (WARN_ON(ioapic < 0))
2744		return -1;
2745
2746	gsi_cfg = mp_ioapic_gsi_routing(ioapic);
2747	if (WARN_ON(gsi > gsi_cfg->gsi_end))
2748		return -1;
2749
2750	return gsi - gsi_cfg->gsi_base;
2751}
2752
2753static int bad_ioapic_register(int idx)
2754{
2755	union IO_APIC_reg_00 reg_00;
2756	union IO_APIC_reg_01 reg_01;
2757	union IO_APIC_reg_02 reg_02;
2758
2759	reg_00.raw = io_apic_read(idx, 0);
2760	reg_01.raw = io_apic_read(idx, 1);
2761	reg_02.raw = io_apic_read(idx, 2);
2762
2763	if (reg_00.raw == -1 && reg_01.raw == -1 && reg_02.raw == -1) {
2764		pr_warn("I/O APIC 0x%x registers return all ones, skipping!\n",
2765			mpc_ioapic_addr(idx));
2766		return 1;
2767	}
2768
2769	return 0;
2770}
2771
2772static int find_free_ioapic_entry(void)
2773{
2774	int idx;
2775
2776	for (idx = 0; idx < MAX_IO_APICS; idx++)
2777		if (ioapics[idx].nr_registers == 0)
2778			return idx;
2779
2780	return MAX_IO_APICS;
2781}
2782
2783/**
2784 * mp_register_ioapic - Register an IOAPIC device
2785 * @id:		hardware IOAPIC ID
2786 * @address:	physical address of IOAPIC register area
2787 * @gsi_base:	base of GSI associated with the IOAPIC
2788 * @cfg:	configuration information for the IOAPIC
2789 */
2790int mp_register_ioapic(int id, u32 address, u32 gsi_base,
2791		       struct ioapic_domain_cfg *cfg)
2792{
2793	bool hotplug = !!ioapic_initialized;
2794	struct mp_ioapic_gsi *gsi_cfg;
2795	int idx, ioapic, entries;
2796	u32 gsi_end;
2797
2798	if (!address) {
2799		pr_warn("Bogus (zero) I/O APIC address found, skipping!\n");
2800		return -EINVAL;
2801	}
2802	for_each_ioapic(ioapic)
2803		if (ioapics[ioapic].mp_config.apicaddr == address) {
2804			pr_warn("address 0x%x conflicts with IOAPIC%d\n",
2805				address, ioapic);
2806			return -EEXIST;
2807		}
2808
2809	idx = find_free_ioapic_entry();
2810	if (idx >= MAX_IO_APICS) {
2811		pr_warn("Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
2812			MAX_IO_APICS, idx);
2813		return -ENOSPC;
2814	}
2815
2816	ioapics[idx].mp_config.type = MP_IOAPIC;
2817	ioapics[idx].mp_config.flags = MPC_APIC_USABLE;
2818	ioapics[idx].mp_config.apicaddr = address;
2819
2820	set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
2821	if (bad_ioapic_register(idx)) {
2822		clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2823		return -ENODEV;
2824	}
2825
2826	ioapics[idx].mp_config.apicid = io_apic_unique_id(idx, id);
2827	ioapics[idx].mp_config.apicver = io_apic_get_version(idx);
2828
2829	/*
2830	 * Build basic GSI lookup table to facilitate gsi->io_apic lookups
2831	 * and to prevent reprogramming of IOAPIC pins (PCI GSIs).
2832	 */
2833	entries = io_apic_get_redir_entries(idx);
2834	gsi_end = gsi_base + entries - 1;
2835	for_each_ioapic(ioapic) {
2836		gsi_cfg = mp_ioapic_gsi_routing(ioapic);
2837		if ((gsi_base >= gsi_cfg->gsi_base &&
2838		     gsi_base <= gsi_cfg->gsi_end) ||
2839		    (gsi_end >= gsi_cfg->gsi_base &&
2840		     gsi_end <= gsi_cfg->gsi_end)) {
2841			pr_warn("GSI range [%u-%u] for new IOAPIC conflicts with GSI[%u-%u]\n",
2842				gsi_base, gsi_end,
2843				gsi_cfg->gsi_base, gsi_cfg->gsi_end);
2844			clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2845			return -ENOSPC;
2846		}
2847	}
2848	gsi_cfg = mp_ioapic_gsi_routing(idx);
2849	gsi_cfg->gsi_base = gsi_base;
2850	gsi_cfg->gsi_end = gsi_end;
2851
2852	ioapics[idx].irqdomain = NULL;
2853	ioapics[idx].irqdomain_cfg = *cfg;
2854
2855	/*
2856	 * If mp_register_ioapic() is called during early boot stage when
2857	 * walking ACPI/SFI/DT tables, it's too early to create irqdomain,
2858	 * we are still using bootmem allocator. So delay it to setup_IO_APIC().
2859	 */
2860	if (hotplug) {
2861		if (mp_irqdomain_create(idx)) {
2862			clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2863			return -ENOMEM;
2864		}
2865		alloc_ioapic_saved_registers(idx);
2866	}
2867
2868	if (gsi_cfg->gsi_end >= gsi_top)
2869		gsi_top = gsi_cfg->gsi_end + 1;
2870	if (nr_ioapics <= idx)
2871		nr_ioapics = idx + 1;
2872
2873	/* Set nr_registers to mark entry present */
2874	ioapics[idx].nr_registers = entries;
2875
2876	pr_info("IOAPIC[%d]: apic_id %d, version %d, address 0x%x, GSI %d-%d\n",
2877		idx, mpc_ioapic_id(idx),
2878		mpc_ioapic_ver(idx), mpc_ioapic_addr(idx),
2879		gsi_cfg->gsi_base, gsi_cfg->gsi_end);
2880
2881	return 0;
2882}
2883
2884int mp_unregister_ioapic(u32 gsi_base)
2885{
2886	int ioapic, pin;
2887	int found = 0;
2888
2889	for_each_ioapic(ioapic)
2890		if (ioapics[ioapic].gsi_config.gsi_base == gsi_base) {
2891			found = 1;
2892			break;
2893		}
2894	if (!found) {
2895		pr_warn("can't find IOAPIC for GSI %d\n", gsi_base);
2896		return -ENODEV;
2897	}
2898
2899	for_each_pin(ioapic, pin) {
2900		u32 gsi = mp_pin_to_gsi(ioapic, pin);
2901		int irq = mp_map_gsi_to_irq(gsi, 0, NULL);
2902		struct mp_chip_data *data;
2903
2904		if (irq >= 0) {
2905			data = irq_get_chip_data(irq);
2906			if (data && data->count) {
2907				pr_warn("pin%d on IOAPIC%d is still in use.\n",
2908					pin, ioapic);
2909				return -EBUSY;
2910			}
2911		}
2912	}
2913
2914	/* Mark entry not present */
2915	ioapics[ioapic].nr_registers  = 0;
2916	ioapic_destroy_irqdomain(ioapic);
2917	free_ioapic_saved_registers(ioapic);
2918	if (ioapics[ioapic].iomem_res)
2919		release_resource(ioapics[ioapic].iomem_res);
2920	clear_fixmap(FIX_IO_APIC_BASE_0 + ioapic);
2921	memset(&ioapics[ioapic], 0, sizeof(ioapics[ioapic]));
2922
2923	return 0;
2924}
2925
2926int mp_ioapic_registered(u32 gsi_base)
2927{
2928	int ioapic;
2929
2930	for_each_ioapic(ioapic)
2931		if (ioapics[ioapic].gsi_config.gsi_base == gsi_base)
2932			return 1;
2933
2934	return 0;
2935}
2936
2937static void mp_irqdomain_get_attr(u32 gsi, struct mp_chip_data *data,
2938				  struct irq_alloc_info *info)
2939{
2940	if (info && info->ioapic_valid) {
2941		data->trigger = info->ioapic_trigger;
2942		data->polarity = info->ioapic_polarity;
2943	} else if (acpi_get_override_irq(gsi, &data->trigger,
2944					 &data->polarity) < 0) {
2945		/* PCI interrupts are always active low level triggered. */
2946		data->trigger = IOAPIC_LEVEL;
2947		data->polarity = IOAPIC_POL_LOW;
2948	}
2949}
2950
2951static void mp_setup_entry(struct irq_cfg *cfg, struct mp_chip_data *data,
2952			   struct IO_APIC_route_entry *entry)
2953{
2954	memset(entry, 0, sizeof(*entry));
2955	entry->delivery_mode = apic->irq_delivery_mode;
2956	entry->dest_mode     = apic->irq_dest_mode;
2957	entry->dest	     = cfg->dest_apicid;
2958	entry->vector	     = cfg->vector;
2959	entry->trigger	     = data->trigger;
2960	entry->polarity	     = data->polarity;
2961	/*
2962	 * Mask level triggered irqs. Edge triggered irqs are masked
2963	 * by the irq core code in case they fire.
2964	 */
2965	if (data->trigger == IOAPIC_LEVEL)
2966		entry->mask = IOAPIC_MASKED;
2967	else
2968		entry->mask = IOAPIC_UNMASKED;
2969}
2970
2971int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
2972		       unsigned int nr_irqs, void *arg)
2973{
2974	int ret, ioapic, pin;
2975	struct irq_cfg *cfg;
2976	struct irq_data *irq_data;
2977	struct mp_chip_data *data;
2978	struct irq_alloc_info *info = arg;
2979	unsigned long flags;
2980
2981	if (!info || nr_irqs > 1)
2982		return -EINVAL;
2983	irq_data = irq_domain_get_irq_data(domain, virq);
2984	if (!irq_data)
2985		return -EINVAL;
2986
2987	ioapic = mp_irqdomain_ioapic_idx(domain);
2988	pin = info->ioapic_pin;
2989	if (irq_find_mapping(domain, (irq_hw_number_t)pin) > 0)
2990		return -EEXIST;
2991
2992	data = kzalloc(sizeof(*data), GFP_KERNEL);
2993	if (!data)
2994		return -ENOMEM;
2995
2996	info->ioapic_entry = &data->entry;
2997	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
2998	if (ret < 0) {
2999		kfree(data);
3000		return ret;
3001	}
3002
3003	INIT_LIST_HEAD(&data->irq_2_pin);
3004	irq_data->hwirq = info->ioapic_pin;
3005	irq_data->chip = (domain->parent == x86_vector_domain) ?
3006			  &ioapic_chip : &ioapic_ir_chip;
3007	irq_data->chip_data = data;
3008	mp_irqdomain_get_attr(mp_pin_to_gsi(ioapic, pin), data, info);
3009
3010	cfg = irqd_cfg(irq_data);
3011	add_pin_to_irq_node(data, ioapic_alloc_attr_node(info), ioapic, pin);
3012
3013	local_irq_save(flags);
3014	if (info->ioapic_entry)
3015		mp_setup_entry(cfg, data, info->ioapic_entry);
3016	mp_register_handler(virq, data->trigger);
3017	if (virq < nr_legacy_irqs())
3018		legacy_pic->mask(virq);
3019	local_irq_restore(flags);
3020
3021	apic_printk(APIC_VERBOSE, KERN_DEBUG
3022		    "IOAPIC[%d]: Set routing entry (%d-%d -> 0x%x -> IRQ %d Mode:%i Active:%i Dest:%d)\n",
3023		    ioapic, mpc_ioapic_id(ioapic), pin, cfg->vector,
3024		    virq, data->trigger, data->polarity, cfg->dest_apicid);
3025
3026	return 0;
3027}
3028
3029void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq,
3030		       unsigned int nr_irqs)
3031{
3032	struct irq_data *irq_data;
3033	struct mp_chip_data *data;
3034
3035	BUG_ON(nr_irqs != 1);
3036	irq_data = irq_domain_get_irq_data(domain, virq);
3037	if (irq_data && irq_data->chip_data) {
3038		data = irq_data->chip_data;
3039		__remove_pin_from_irq(data, mp_irqdomain_ioapic_idx(domain),
3040				      (int)irq_data->hwirq);
3041		WARN_ON(!list_empty(&data->irq_2_pin));
3042		kfree(irq_data->chip_data);
3043	}
3044	irq_domain_free_irqs_top(domain, virq, nr_irqs);
3045}
3046
3047int mp_irqdomain_activate(struct irq_domain *domain,
3048			  struct irq_data *irq_data, bool reserve)
3049{
3050	unsigned long flags;
3051
3052	raw_spin_lock_irqsave(&ioapic_lock, flags);
3053	ioapic_configure_entry(irq_data);
3054	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
3055	return 0;
3056}
3057
3058void mp_irqdomain_deactivate(struct irq_domain *domain,
3059			     struct irq_data *irq_data)
3060{
3061	/* It won't be called for IRQ with multiple IOAPIC pins associated */
3062	ioapic_mask_entry(mp_irqdomain_ioapic_idx(domain),
3063			  (int)irq_data->hwirq);
3064}
3065
3066int mp_irqdomain_ioapic_idx(struct irq_domain *domain)
3067{
3068	return (int)(long)domain->host_data;
3069}
3070
3071const struct irq_domain_ops mp_ioapic_irqdomain_ops = {
3072	.alloc		= mp_irqdomain_alloc,
3073	.free		= mp_irqdomain_free,
3074	.activate	= mp_irqdomain_activate,
3075	.deactivate	= mp_irqdomain_deactivate,
3076};
v5.9
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *	Intel IO-APIC support for multi-Pentium hosts.
   4 *
   5 *	Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
   6 *
   7 *	Many thanks to Stig Venaas for trying out countless experimental
   8 *	patches and reporting/debugging problems patiently!
   9 *
  10 *	(c) 1999, Multiple IO-APIC support, developed by
  11 *	Ken-ichi Yaku <yaku@css1.kbnes.nec.co.jp> and
  12 *      Hidemi Kishimoto <kisimoto@css1.kbnes.nec.co.jp>,
  13 *	further tested and cleaned up by Zach Brown <zab@redhat.com>
  14 *	and Ingo Molnar <mingo@redhat.com>
  15 *
  16 *	Fixes
  17 *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
  18 *					thanks to Eric Gilmore
  19 *					and Rolf G. Tews
  20 *					for testing these extensively
  21 *	Paul Diefenbaugh	:	Added full ACPI support
  22 *
  23 * Historical information which is worth to be preserved:
  24 *
  25 * - SiS APIC rmw bug:
  26 *
  27 *	We used to have a workaround for a bug in SiS chips which
  28 *	required to rewrite the index register for a read-modify-write
  29 *	operation as the chip lost the index information which was
  30 *	setup for the read already. We cache the data now, so that
  31 *	workaround has been removed.
  32 */
  33
  34#include <linux/mm.h>
  35#include <linux/interrupt.h>
  36#include <linux/irq.h>
  37#include <linux/init.h>
  38#include <linux/delay.h>
  39#include <linux/sched.h>
  40#include <linux/pci.h>
  41#include <linux/mc146818rtc.h>
  42#include <linux/compiler.h>
  43#include <linux/acpi.h>
  44#include <linux/export.h>
  45#include <linux/syscore_ops.h>
  46#include <linux/freezer.h>
  47#include <linux/kthread.h>
  48#include <linux/jiffies.h>	/* time_after() */
  49#include <linux/slab.h>
  50#include <linux/memblock.h>
  51
  52#include <asm/irqdomain.h>
  53#include <asm/io.h>
  54#include <asm/smp.h>
  55#include <asm/cpu.h>
  56#include <asm/desc.h>
  57#include <asm/proto.h>
  58#include <asm/acpi.h>
  59#include <asm/dma.h>
  60#include <asm/timer.h>
  61#include <asm/time.h>
  62#include <asm/i8259.h>
  63#include <asm/setup.h>
  64#include <asm/irq_remapping.h>
  65#include <asm/hw_irq.h>
  66
  67#include <asm/apic.h>
  68
  69#define	for_each_ioapic(idx)		\
  70	for ((idx) = 0; (idx) < nr_ioapics; (idx)++)
  71#define	for_each_ioapic_reverse(idx)	\
  72	for ((idx) = nr_ioapics - 1; (idx) >= 0; (idx)--)
  73#define	for_each_pin(idx, pin)		\
  74	for ((pin) = 0; (pin) < ioapics[(idx)].nr_registers; (pin)++)
  75#define	for_each_ioapic_pin(idx, pin)	\
  76	for_each_ioapic((idx))		\
  77		for_each_pin((idx), (pin))
  78#define for_each_irq_pin(entry, head) \
  79	list_for_each_entry(entry, &head, list)
  80
  81static DEFINE_RAW_SPINLOCK(ioapic_lock);
  82static DEFINE_MUTEX(ioapic_mutex);
  83static unsigned int ioapic_dynirq_base;
  84static int ioapic_initialized;
  85
  86struct irq_pin_list {
  87	struct list_head list;
  88	int apic, pin;
  89};
  90
  91struct mp_chip_data {
  92	struct list_head irq_2_pin;
  93	struct IO_APIC_route_entry entry;
  94	int trigger;
  95	int polarity;
  96	u32 count;
  97	bool isa_irq;
  98};
  99
 100struct mp_ioapic_gsi {
 101	u32 gsi_base;
 102	u32 gsi_end;
 103};
 104
 105static struct ioapic {
 106	/*
 107	 * # of IRQ routing registers
 108	 */
 109	int nr_registers;
 110	/*
 111	 * Saved state during suspend/resume, or while enabling intr-remap.
 112	 */
 113	struct IO_APIC_route_entry *saved_registers;
 114	/* I/O APIC config */
 115	struct mpc_ioapic mp_config;
 116	/* IO APIC gsi routing info */
 117	struct mp_ioapic_gsi  gsi_config;
 118	struct ioapic_domain_cfg irqdomain_cfg;
 119	struct irq_domain *irqdomain;
 120	struct resource *iomem_res;
 121} ioapics[MAX_IO_APICS];
 122
 123#define mpc_ioapic_ver(ioapic_idx)	ioapics[ioapic_idx].mp_config.apicver
 124
 125int mpc_ioapic_id(int ioapic_idx)
 126{
 127	return ioapics[ioapic_idx].mp_config.apicid;
 128}
 129
 130unsigned int mpc_ioapic_addr(int ioapic_idx)
 131{
 132	return ioapics[ioapic_idx].mp_config.apicaddr;
 133}
 134
 135static inline struct mp_ioapic_gsi *mp_ioapic_gsi_routing(int ioapic_idx)
 136{
 137	return &ioapics[ioapic_idx].gsi_config;
 138}
 139
 140static inline int mp_ioapic_pin_count(int ioapic)
 141{
 142	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic);
 143
 144	return gsi_cfg->gsi_end - gsi_cfg->gsi_base + 1;
 145}
 146
 147static inline u32 mp_pin_to_gsi(int ioapic, int pin)
 148{
 149	return mp_ioapic_gsi_routing(ioapic)->gsi_base + pin;
 150}
 151
 152static inline bool mp_is_legacy_irq(int irq)
 153{
 154	return irq >= 0 && irq < nr_legacy_irqs();
 155}
 156
 
 
 
 
 
 
 
 
 
 
 
 
 
 157static inline struct irq_domain *mp_ioapic_irqdomain(int ioapic)
 158{
 159	return ioapics[ioapic].irqdomain;
 160}
 161
 162int nr_ioapics;
 163
 164/* The one past the highest gsi number used */
 165u32 gsi_top;
 166
 167/* MP IRQ source entries */
 168struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
 169
 170/* # of MP IRQ source entries */
 171int mp_irq_entries;
 172
 173#ifdef CONFIG_EISA
 174int mp_bus_id_to_type[MAX_MP_BUSSES];
 175#endif
 176
 177DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES);
 178
 179int skip_ioapic_setup;
 180
 181/**
 182 * disable_ioapic_support() - disables ioapic support at runtime
 183 */
 184void disable_ioapic_support(void)
 185{
 186#ifdef CONFIG_PCI
 187	noioapicquirk = 1;
 188	noioapicreroute = -1;
 189#endif
 190	skip_ioapic_setup = 1;
 191}
 192
 193static int __init parse_noapic(char *str)
 194{
 195	/* disable IO-APIC */
 196	disable_ioapic_support();
 197	return 0;
 198}
 199early_param("noapic", parse_noapic);
 200
 201/* Will be called in mpparse/acpi/sfi codes for saving IRQ info */
 202void mp_save_irq(struct mpc_intsrc *m)
 203{
 204	int i;
 205
 206	apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
 207		" IRQ %02x, APIC ID %x, APIC INT %02x\n",
 208		m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbus,
 209		m->srcbusirq, m->dstapic, m->dstirq);
 210
 211	for (i = 0; i < mp_irq_entries; i++) {
 212		if (!memcmp(&mp_irqs[i], m, sizeof(*m)))
 213			return;
 214	}
 215
 216	memcpy(&mp_irqs[mp_irq_entries], m, sizeof(*m));
 217	if (++mp_irq_entries == MAX_IRQ_SOURCES)
 218		panic("Max # of irq sources exceeded!!\n");
 219}
 220
 221static void alloc_ioapic_saved_registers(int idx)
 222{
 223	size_t size;
 224
 225	if (ioapics[idx].saved_registers)
 226		return;
 227
 228	size = sizeof(struct IO_APIC_route_entry) * ioapics[idx].nr_registers;
 229	ioapics[idx].saved_registers = kzalloc(size, GFP_KERNEL);
 230	if (!ioapics[idx].saved_registers)
 231		pr_err("IOAPIC %d: suspend/resume impossible!\n", idx);
 232}
 233
 234static void free_ioapic_saved_registers(int idx)
 235{
 236	kfree(ioapics[idx].saved_registers);
 237	ioapics[idx].saved_registers = NULL;
 238}
 239
 240int __init arch_early_ioapic_init(void)
 241{
 242	int i;
 243
 244	if (!nr_legacy_irqs())
 245		io_apic_irqs = ~0UL;
 246
 247	for_each_ioapic(i)
 248		alloc_ioapic_saved_registers(i);
 249
 250	return 0;
 251}
 252
 253struct io_apic {
 254	unsigned int index;
 255	unsigned int unused[3];
 256	unsigned int data;
 257	unsigned int unused2[11];
 258	unsigned int eoi;
 259};
 260
 261static __attribute_const__ struct io_apic __iomem *io_apic_base(int idx)
 262{
 263	return (void __iomem *) __fix_to_virt(FIX_IO_APIC_BASE_0 + idx)
 264		+ (mpc_ioapic_addr(idx) & ~PAGE_MASK);
 265}
 266
 267static inline void io_apic_eoi(unsigned int apic, unsigned int vector)
 268{
 269	struct io_apic __iomem *io_apic = io_apic_base(apic);
 270	writel(vector, &io_apic->eoi);
 271}
 272
 273unsigned int native_io_apic_read(unsigned int apic, unsigned int reg)
 274{
 275	struct io_apic __iomem *io_apic = io_apic_base(apic);
 276	writel(reg, &io_apic->index);
 277	return readl(&io_apic->data);
 278}
 279
 280static void io_apic_write(unsigned int apic, unsigned int reg,
 281			  unsigned int value)
 282{
 283	struct io_apic __iomem *io_apic = io_apic_base(apic);
 284
 285	writel(reg, &io_apic->index);
 286	writel(value, &io_apic->data);
 287}
 288
 289union entry_union {
 290	struct { u32 w1, w2; };
 291	struct IO_APIC_route_entry entry;
 292};
 293
 294static struct IO_APIC_route_entry __ioapic_read_entry(int apic, int pin)
 295{
 296	union entry_union eu;
 297
 298	eu.w1 = io_apic_read(apic, 0x10 + 2 * pin);
 299	eu.w2 = io_apic_read(apic, 0x11 + 2 * pin);
 300
 301	return eu.entry;
 302}
 303
 304static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin)
 305{
 306	union entry_union eu;
 307	unsigned long flags;
 308
 309	raw_spin_lock_irqsave(&ioapic_lock, flags);
 310	eu.entry = __ioapic_read_entry(apic, pin);
 311	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 312
 313	return eu.entry;
 314}
 315
 316/*
 317 * When we write a new IO APIC routing entry, we need to write the high
 318 * word first! If the mask bit in the low word is clear, we will enable
 319 * the interrupt, and we need to make sure the entry is fully populated
 320 * before that happens.
 321 */
 322static void __ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
 323{
 324	union entry_union eu = {{0, 0}};
 325
 326	eu.entry = e;
 327	io_apic_write(apic, 0x11 + 2*pin, eu.w2);
 328	io_apic_write(apic, 0x10 + 2*pin, eu.w1);
 329}
 330
 331static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e)
 332{
 333	unsigned long flags;
 334
 335	raw_spin_lock_irqsave(&ioapic_lock, flags);
 336	__ioapic_write_entry(apic, pin, e);
 337	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 338}
 339
 340/*
 341 * When we mask an IO APIC routing entry, we need to write the low
 342 * word first, in order to set the mask bit before we change the
 343 * high bits!
 344 */
 345static void ioapic_mask_entry(int apic, int pin)
 346{
 347	unsigned long flags;
 348	union entry_union eu = { .entry.mask = IOAPIC_MASKED };
 349
 350	raw_spin_lock_irqsave(&ioapic_lock, flags);
 351	io_apic_write(apic, 0x10 + 2*pin, eu.w1);
 352	io_apic_write(apic, 0x11 + 2*pin, eu.w2);
 353	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 354}
 355
 356/*
 357 * The common case is 1:1 IRQ<->pin mappings. Sometimes there are
 358 * shared ISA-space IRQs, so we have to support them. We are super
 359 * fast in the common case, and fast for shared ISA-space IRQs.
 360 */
 361static int __add_pin_to_irq_node(struct mp_chip_data *data,
 362				 int node, int apic, int pin)
 363{
 364	struct irq_pin_list *entry;
 365
 366	/* don't allow duplicates */
 367	for_each_irq_pin(entry, data->irq_2_pin)
 368		if (entry->apic == apic && entry->pin == pin)
 369			return 0;
 370
 371	entry = kzalloc_node(sizeof(struct irq_pin_list), GFP_ATOMIC, node);
 372	if (!entry) {
 373		pr_err("can not alloc irq_pin_list (%d,%d,%d)\n",
 374		       node, apic, pin);
 375		return -ENOMEM;
 376	}
 377	entry->apic = apic;
 378	entry->pin = pin;
 379	list_add_tail(&entry->list, &data->irq_2_pin);
 380
 381	return 0;
 382}
 383
 384static void __remove_pin_from_irq(struct mp_chip_data *data, int apic, int pin)
 385{
 386	struct irq_pin_list *tmp, *entry;
 387
 388	list_for_each_entry_safe(entry, tmp, &data->irq_2_pin, list)
 389		if (entry->apic == apic && entry->pin == pin) {
 390			list_del(&entry->list);
 391			kfree(entry);
 392			return;
 393		}
 394}
 395
 396static void add_pin_to_irq_node(struct mp_chip_data *data,
 397				int node, int apic, int pin)
 398{
 399	if (__add_pin_to_irq_node(data, node, apic, pin))
 400		panic("IO-APIC: failed to add irq-pin. Can not proceed\n");
 401}
 402
 403/*
 404 * Reroute an IRQ to a different pin.
 405 */
 406static void __init replace_pin_at_irq_node(struct mp_chip_data *data, int node,
 407					   int oldapic, int oldpin,
 408					   int newapic, int newpin)
 409{
 410	struct irq_pin_list *entry;
 411
 412	for_each_irq_pin(entry, data->irq_2_pin) {
 413		if (entry->apic == oldapic && entry->pin == oldpin) {
 414			entry->apic = newapic;
 415			entry->pin = newpin;
 416			/* every one is different, right? */
 417			return;
 418		}
 419	}
 420
 421	/* old apic/pin didn't exist, so just add new ones */
 422	add_pin_to_irq_node(data, node, newapic, newpin);
 423}
 424
 425static void io_apic_modify_irq(struct mp_chip_data *data,
 426			       int mask_and, int mask_or,
 427			       void (*final)(struct irq_pin_list *entry))
 428{
 429	union entry_union eu;
 430	struct irq_pin_list *entry;
 431
 432	eu.entry = data->entry;
 433	eu.w1 &= mask_and;
 434	eu.w1 |= mask_or;
 435	data->entry = eu.entry;
 436
 437	for_each_irq_pin(entry, data->irq_2_pin) {
 438		io_apic_write(entry->apic, 0x10 + 2 * entry->pin, eu.w1);
 439		if (final)
 440			final(entry);
 441	}
 442}
 443
 444static void io_apic_sync(struct irq_pin_list *entry)
 445{
 446	/*
 447	 * Synchronize the IO-APIC and the CPU by doing
 448	 * a dummy read from the IO-APIC
 449	 */
 450	struct io_apic __iomem *io_apic;
 451
 452	io_apic = io_apic_base(entry->apic);
 453	readl(&io_apic->data);
 454}
 455
 456static void mask_ioapic_irq(struct irq_data *irq_data)
 457{
 458	struct mp_chip_data *data = irq_data->chip_data;
 459	unsigned long flags;
 460
 461	raw_spin_lock_irqsave(&ioapic_lock, flags);
 462	io_apic_modify_irq(data, ~0, IO_APIC_REDIR_MASKED, &io_apic_sync);
 463	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 464}
 465
 466static void __unmask_ioapic(struct mp_chip_data *data)
 467{
 468	io_apic_modify_irq(data, ~IO_APIC_REDIR_MASKED, 0, NULL);
 469}
 470
 471static void unmask_ioapic_irq(struct irq_data *irq_data)
 472{
 473	struct mp_chip_data *data = irq_data->chip_data;
 474	unsigned long flags;
 475
 476	raw_spin_lock_irqsave(&ioapic_lock, flags);
 477	__unmask_ioapic(data);
 478	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 479}
 480
 481/*
 482 * IO-APIC versions below 0x20 don't support EOI register.
 483 * For the record, here is the information about various versions:
 484 *     0Xh     82489DX
 485 *     1Xh     I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
 486 *     2Xh     I/O(x)APIC which is PCI 2.2 Compliant
 487 *     30h-FFh Reserved
 488 *
 489 * Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
 490 * version as 0x2. This is an error with documentation and these ICH chips
 491 * use io-apic's of version 0x20.
 492 *
 493 * For IO-APIC's with EOI register, we use that to do an explicit EOI.
 494 * Otherwise, we simulate the EOI message manually by changing the trigger
 495 * mode to edge and then back to level, with RTE being masked during this.
 496 */
 497static void __eoi_ioapic_pin(int apic, int pin, int vector)
 498{
 499	if (mpc_ioapic_ver(apic) >= 0x20) {
 500		io_apic_eoi(apic, vector);
 501	} else {
 502		struct IO_APIC_route_entry entry, entry1;
 503
 504		entry = entry1 = __ioapic_read_entry(apic, pin);
 505
 506		/*
 507		 * Mask the entry and change the trigger mode to edge.
 508		 */
 509		entry1.mask = IOAPIC_MASKED;
 510		entry1.trigger = IOAPIC_EDGE;
 511
 512		__ioapic_write_entry(apic, pin, entry1);
 513
 514		/*
 515		 * Restore the previous level triggered entry.
 516		 */
 517		__ioapic_write_entry(apic, pin, entry);
 518	}
 519}
 520
 521static void eoi_ioapic_pin(int vector, struct mp_chip_data *data)
 522{
 523	unsigned long flags;
 524	struct irq_pin_list *entry;
 525
 526	raw_spin_lock_irqsave(&ioapic_lock, flags);
 527	for_each_irq_pin(entry, data->irq_2_pin)
 528		__eoi_ioapic_pin(entry->apic, entry->pin, vector);
 529	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 530}
 531
 532static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
 533{
 534	struct IO_APIC_route_entry entry;
 535
 536	/* Check delivery_mode to be sure we're not clearing an SMI pin */
 537	entry = ioapic_read_entry(apic, pin);
 538	if (entry.delivery_mode == dest_SMI)
 539		return;
 540
 541	/*
 542	 * Make sure the entry is masked and re-read the contents to check
 543	 * if it is a level triggered pin and if the remote-IRR is set.
 544	 */
 545	if (entry.mask == IOAPIC_UNMASKED) {
 546		entry.mask = IOAPIC_MASKED;
 547		ioapic_write_entry(apic, pin, entry);
 548		entry = ioapic_read_entry(apic, pin);
 549	}
 550
 551	if (entry.irr) {
 552		unsigned long flags;
 553
 554		/*
 555		 * Make sure the trigger mode is set to level. Explicit EOI
 556		 * doesn't clear the remote-IRR if the trigger mode is not
 557		 * set to level.
 558		 */
 559		if (entry.trigger == IOAPIC_EDGE) {
 560			entry.trigger = IOAPIC_LEVEL;
 561			ioapic_write_entry(apic, pin, entry);
 562		}
 563		raw_spin_lock_irqsave(&ioapic_lock, flags);
 564		__eoi_ioapic_pin(apic, pin, entry.vector);
 565		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 566	}
 567
 568	/*
 569	 * Clear the rest of the bits in the IO-APIC RTE except for the mask
 570	 * bit.
 571	 */
 572	ioapic_mask_entry(apic, pin);
 573	entry = ioapic_read_entry(apic, pin);
 574	if (entry.irr)
 575		pr_err("Unable to reset IRR for apic: %d, pin :%d\n",
 576		       mpc_ioapic_id(apic), pin);
 577}
 578
 579void clear_IO_APIC (void)
 580{
 581	int apic, pin;
 582
 583	for_each_ioapic_pin(apic, pin)
 584		clear_IO_APIC_pin(apic, pin);
 585}
 586
 587#ifdef CONFIG_X86_32
 588/*
 589 * support for broken MP BIOSs, enables hand-redirection of PIRQ0-7 to
 590 * specific CPU-side IRQs.
 591 */
 592
 593#define MAX_PIRQS 8
 594static int pirq_entries[MAX_PIRQS] = {
 595	[0 ... MAX_PIRQS - 1] = -1
 596};
 597
 598static int __init ioapic_pirq_setup(char *str)
 599{
 600	int i, max;
 601	int ints[MAX_PIRQS+1];
 602
 603	get_options(str, ARRAY_SIZE(ints), ints);
 604
 605	apic_printk(APIC_VERBOSE, KERN_INFO
 606			"PIRQ redirection, working around broken MP-BIOS.\n");
 607	max = MAX_PIRQS;
 608	if (ints[0] < MAX_PIRQS)
 609		max = ints[0];
 610
 611	for (i = 0; i < max; i++) {
 612		apic_printk(APIC_VERBOSE, KERN_DEBUG
 613				"... PIRQ%d -> IRQ %d\n", i, ints[i+1]);
 614		/*
 615		 * PIRQs are mapped upside down, usually.
 616		 */
 617		pirq_entries[MAX_PIRQS-i-1] = ints[i+1];
 618	}
 619	return 1;
 620}
 621
 622__setup("pirq=", ioapic_pirq_setup);
 623#endif /* CONFIG_X86_32 */
 624
 625/*
 626 * Saves all the IO-APIC RTE's
 627 */
 628int save_ioapic_entries(void)
 629{
 630	int apic, pin;
 631	int err = 0;
 632
 633	for_each_ioapic(apic) {
 634		if (!ioapics[apic].saved_registers) {
 635			err = -ENOMEM;
 636			continue;
 637		}
 638
 639		for_each_pin(apic, pin)
 640			ioapics[apic].saved_registers[pin] =
 641				ioapic_read_entry(apic, pin);
 642	}
 643
 644	return err;
 645}
 646
 647/*
 648 * Mask all IO APIC entries.
 649 */
 650void mask_ioapic_entries(void)
 651{
 652	int apic, pin;
 653
 654	for_each_ioapic(apic) {
 655		if (!ioapics[apic].saved_registers)
 656			continue;
 657
 658		for_each_pin(apic, pin) {
 659			struct IO_APIC_route_entry entry;
 660
 661			entry = ioapics[apic].saved_registers[pin];
 662			if (entry.mask == IOAPIC_UNMASKED) {
 663				entry.mask = IOAPIC_MASKED;
 664				ioapic_write_entry(apic, pin, entry);
 665			}
 666		}
 667	}
 668}
 669
 670/*
 671 * Restore IO APIC entries which was saved in the ioapic structure.
 672 */
 673int restore_ioapic_entries(void)
 674{
 675	int apic, pin;
 676
 677	for_each_ioapic(apic) {
 678		if (!ioapics[apic].saved_registers)
 679			continue;
 680
 681		for_each_pin(apic, pin)
 682			ioapic_write_entry(apic, pin,
 683					   ioapics[apic].saved_registers[pin]);
 684	}
 685	return 0;
 686}
 687
 688/*
 689 * Find the IRQ entry number of a certain pin.
 690 */
 691static int find_irq_entry(int ioapic_idx, int pin, int type)
 692{
 693	int i;
 694
 695	for (i = 0; i < mp_irq_entries; i++)
 696		if (mp_irqs[i].irqtype == type &&
 697		    (mp_irqs[i].dstapic == mpc_ioapic_id(ioapic_idx) ||
 698		     mp_irqs[i].dstapic == MP_APIC_ALL) &&
 699		    mp_irqs[i].dstirq == pin)
 700			return i;
 701
 702	return -1;
 703}
 704
 705/*
 706 * Find the pin to which IRQ[irq] (ISA) is connected
 707 */
 708static int __init find_isa_irq_pin(int irq, int type)
 709{
 710	int i;
 711
 712	for (i = 0; i < mp_irq_entries; i++) {
 713		int lbus = mp_irqs[i].srcbus;
 714
 715		if (test_bit(lbus, mp_bus_not_pci) &&
 716		    (mp_irqs[i].irqtype == type) &&
 717		    (mp_irqs[i].srcbusirq == irq))
 718
 719			return mp_irqs[i].dstirq;
 720	}
 721	return -1;
 722}
 723
 724static int __init find_isa_irq_apic(int irq, int type)
 725{
 726	int i;
 727
 728	for (i = 0; i < mp_irq_entries; i++) {
 729		int lbus = mp_irqs[i].srcbus;
 730
 731		if (test_bit(lbus, mp_bus_not_pci) &&
 732		    (mp_irqs[i].irqtype == type) &&
 733		    (mp_irqs[i].srcbusirq == irq))
 734			break;
 735	}
 736
 737	if (i < mp_irq_entries) {
 738		int ioapic_idx;
 739
 740		for_each_ioapic(ioapic_idx)
 741			if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic)
 742				return ioapic_idx;
 743	}
 744
 745	return -1;
 746}
 747
 748#ifdef CONFIG_EISA
 749/*
 750 * EISA Edge/Level control register, ELCR
 751 */
 752static int EISA_ELCR(unsigned int irq)
 753{
 754	if (irq < nr_legacy_irqs()) {
 755		unsigned int port = 0x4d0 + (irq >> 3);
 756		return (inb(port) >> (irq & 7)) & 1;
 757	}
 758	apic_printk(APIC_VERBOSE, KERN_INFO
 759			"Broken MPtable reports ISA irq %d\n", irq);
 760	return 0;
 761}
 762
 763#endif
 764
 765/* ISA interrupts are always active high edge triggered,
 766 * when listed as conforming in the MP table. */
 767
 768#define default_ISA_trigger(idx)	(IOAPIC_EDGE)
 769#define default_ISA_polarity(idx)	(IOAPIC_POL_HIGH)
 770
 771/* EISA interrupts are always polarity zero and can be edge or level
 772 * trigger depending on the ELCR value.  If an interrupt is listed as
 773 * EISA conforming in the MP table, that means its trigger type must
 774 * be read in from the ELCR */
 775
 776#define default_EISA_trigger(idx)	(EISA_ELCR(mp_irqs[idx].srcbusirq))
 777#define default_EISA_polarity(idx)	default_ISA_polarity(idx)
 778
 779/* PCI interrupts are always active low level triggered,
 780 * when listed as conforming in the MP table. */
 781
 782#define default_PCI_trigger(idx)	(IOAPIC_LEVEL)
 783#define default_PCI_polarity(idx)	(IOAPIC_POL_LOW)
 784
 785static int irq_polarity(int idx)
 786{
 787	int bus = mp_irqs[idx].srcbus;
 788
 789	/*
 790	 * Determine IRQ line polarity (high active or low active):
 791	 */
 792	switch (mp_irqs[idx].irqflag & MP_IRQPOL_MASK) {
 793	case MP_IRQPOL_DEFAULT:
 794		/* conforms to spec, ie. bus-type dependent polarity */
 795		if (test_bit(bus, mp_bus_not_pci))
 796			return default_ISA_polarity(idx);
 797		else
 798			return default_PCI_polarity(idx);
 799	case MP_IRQPOL_ACTIVE_HIGH:
 800		return IOAPIC_POL_HIGH;
 801	case MP_IRQPOL_RESERVED:
 802		pr_warn("IOAPIC: Invalid polarity: 2, defaulting to low\n");
 803		fallthrough;
 804	case MP_IRQPOL_ACTIVE_LOW:
 805	default: /* Pointless default required due to do gcc stupidity */
 806		return IOAPIC_POL_LOW;
 807	}
 808}
 809
 810#ifdef CONFIG_EISA
 811static int eisa_irq_trigger(int idx, int bus, int trigger)
 812{
 813	switch (mp_bus_id_to_type[bus]) {
 814	case MP_BUS_PCI:
 815	case MP_BUS_ISA:
 816		return trigger;
 817	case MP_BUS_EISA:
 818		return default_EISA_trigger(idx);
 819	}
 820	pr_warn("IOAPIC: Invalid srcbus: %d defaulting to level\n", bus);
 821	return IOAPIC_LEVEL;
 822}
 823#else
 824static inline int eisa_irq_trigger(int idx, int bus, int trigger)
 825{
 826	return trigger;
 827}
 828#endif
 829
 830static int irq_trigger(int idx)
 831{
 832	int bus = mp_irqs[idx].srcbus;
 833	int trigger;
 834
 835	/*
 836	 * Determine IRQ trigger mode (edge or level sensitive):
 837	 */
 838	switch (mp_irqs[idx].irqflag & MP_IRQTRIG_MASK) {
 839	case MP_IRQTRIG_DEFAULT:
 840		/* conforms to spec, ie. bus-type dependent trigger mode */
 841		if (test_bit(bus, mp_bus_not_pci))
 842			trigger = default_ISA_trigger(idx);
 843		else
 844			trigger = default_PCI_trigger(idx);
 845		/* Take EISA into account */
 846		return eisa_irq_trigger(idx, bus, trigger);
 847	case MP_IRQTRIG_EDGE:
 848		return IOAPIC_EDGE;
 849	case MP_IRQTRIG_RESERVED:
 850		pr_warn("IOAPIC: Invalid trigger mode 2 defaulting to level\n");
 851		fallthrough;
 852	case MP_IRQTRIG_LEVEL:
 853	default: /* Pointless default required due to do gcc stupidity */
 854		return IOAPIC_LEVEL;
 855	}
 856}
 857
 858void ioapic_set_alloc_attr(struct irq_alloc_info *info, int node,
 859			   int trigger, int polarity)
 860{
 861	init_irq_alloc_info(info, NULL);
 862	info->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
 863	info->ioapic_node = node;
 864	info->ioapic_trigger = trigger;
 865	info->ioapic_polarity = polarity;
 866	info->ioapic_valid = 1;
 867}
 868
 869#ifndef CONFIG_ACPI
 870int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity);
 871#endif
 872
 873static void ioapic_copy_alloc_attr(struct irq_alloc_info *dst,
 874				   struct irq_alloc_info *src,
 875				   u32 gsi, int ioapic_idx, int pin)
 876{
 877	int trigger, polarity;
 878
 879	copy_irq_alloc_info(dst, src);
 880	dst->type = X86_IRQ_ALLOC_TYPE_IOAPIC;
 881	dst->ioapic_id = mpc_ioapic_id(ioapic_idx);
 882	dst->ioapic_pin = pin;
 883	dst->ioapic_valid = 1;
 884	if (src && src->ioapic_valid) {
 885		dst->ioapic_node = src->ioapic_node;
 886		dst->ioapic_trigger = src->ioapic_trigger;
 887		dst->ioapic_polarity = src->ioapic_polarity;
 888	} else {
 889		dst->ioapic_node = NUMA_NO_NODE;
 890		if (acpi_get_override_irq(gsi, &trigger, &polarity) >= 0) {
 891			dst->ioapic_trigger = trigger;
 892			dst->ioapic_polarity = polarity;
 893		} else {
 894			/*
 895			 * PCI interrupts are always active low level
 896			 * triggered.
 897			 */
 898			dst->ioapic_trigger = IOAPIC_LEVEL;
 899			dst->ioapic_polarity = IOAPIC_POL_LOW;
 900		}
 901	}
 902}
 903
 904static int ioapic_alloc_attr_node(struct irq_alloc_info *info)
 905{
 906	return (info && info->ioapic_valid) ? info->ioapic_node : NUMA_NO_NODE;
 907}
 908
 909static void mp_register_handler(unsigned int irq, unsigned long trigger)
 910{
 911	irq_flow_handler_t hdl;
 912	bool fasteoi;
 913
 914	if (trigger) {
 915		irq_set_status_flags(irq, IRQ_LEVEL);
 916		fasteoi = true;
 917	} else {
 918		irq_clear_status_flags(irq, IRQ_LEVEL);
 919		fasteoi = false;
 920	}
 921
 922	hdl = fasteoi ? handle_fasteoi_irq : handle_edge_irq;
 923	__irq_set_handler(irq, hdl, 0, fasteoi ? "fasteoi" : "edge");
 924}
 925
 926static bool mp_check_pin_attr(int irq, struct irq_alloc_info *info)
 927{
 928	struct mp_chip_data *data = irq_get_chip_data(irq);
 929
 930	/*
 931	 * setup_IO_APIC_irqs() programs all legacy IRQs with default trigger
 932	 * and polarity attirbutes. So allow the first user to reprogram the
 933	 * pin with real trigger and polarity attributes.
 934	 */
 935	if (irq < nr_legacy_irqs() && data->count == 1) {
 936		if (info->ioapic_trigger != data->trigger)
 937			mp_register_handler(irq, info->ioapic_trigger);
 938		data->entry.trigger = data->trigger = info->ioapic_trigger;
 939		data->entry.polarity = data->polarity = info->ioapic_polarity;
 940	}
 941
 942	return data->trigger == info->ioapic_trigger &&
 943	       data->polarity == info->ioapic_polarity;
 944}
 945
 946static int alloc_irq_from_domain(struct irq_domain *domain, int ioapic, u32 gsi,
 947				 struct irq_alloc_info *info)
 948{
 949	bool legacy = false;
 950	int irq = -1;
 951	int type = ioapics[ioapic].irqdomain_cfg.type;
 952
 953	switch (type) {
 954	case IOAPIC_DOMAIN_LEGACY:
 955		/*
 956		 * Dynamically allocate IRQ number for non-ISA IRQs in the first
 957		 * 16 GSIs on some weird platforms.
 958		 */
 959		if (!ioapic_initialized || gsi >= nr_legacy_irqs())
 960			irq = gsi;
 961		legacy = mp_is_legacy_irq(irq);
 962		break;
 963	case IOAPIC_DOMAIN_STRICT:
 964		irq = gsi;
 965		break;
 966	case IOAPIC_DOMAIN_DYNAMIC:
 967		break;
 968	default:
 969		WARN(1, "ioapic: unknown irqdomain type %d\n", type);
 970		return -1;
 971	}
 972
 973	return __irq_domain_alloc_irqs(domain, irq, 1,
 974				       ioapic_alloc_attr_node(info),
 975				       info, legacy, NULL);
 976}
 977
 978/*
 979 * Need special handling for ISA IRQs because there may be multiple IOAPIC pins
 980 * sharing the same ISA IRQ number and irqdomain only supports 1:1 mapping
 981 * between IOAPIC pin and IRQ number. A typical IOAPIC has 24 pins, pin 0-15 are
 982 * used for legacy IRQs and pin 16-23 are used for PCI IRQs (PIRQ A-H).
 983 * When ACPI is disabled, only legacy IRQ numbers (IRQ0-15) are available, and
 984 * some BIOSes may use MP Interrupt Source records to override IRQ numbers for
 985 * PIRQs instead of reprogramming the interrupt routing logic. Thus there may be
 986 * multiple pins sharing the same legacy IRQ number when ACPI is disabled.
 987 */
 988static int alloc_isa_irq_from_domain(struct irq_domain *domain,
 989				     int irq, int ioapic, int pin,
 990				     struct irq_alloc_info *info)
 991{
 992	struct mp_chip_data *data;
 993	struct irq_data *irq_data = irq_get_irq_data(irq);
 994	int node = ioapic_alloc_attr_node(info);
 995
 996	/*
 997	 * Legacy ISA IRQ has already been allocated, just add pin to
 998	 * the pin list assoicated with this IRQ and program the IOAPIC
 999	 * entry. The IOAPIC entry
1000	 */
1001	if (irq_data && irq_data->parent_data) {
1002		if (!mp_check_pin_attr(irq, info))
1003			return -EBUSY;
1004		if (__add_pin_to_irq_node(irq_data->chip_data, node, ioapic,
1005					  info->ioapic_pin))
1006			return -ENOMEM;
1007	} else {
1008		info->flags |= X86_IRQ_ALLOC_LEGACY;
1009		irq = __irq_domain_alloc_irqs(domain, irq, 1, node, info, true,
1010					      NULL);
1011		if (irq >= 0) {
1012			irq_data = irq_domain_get_irq_data(domain, irq);
1013			data = irq_data->chip_data;
1014			data->isa_irq = true;
1015		}
1016	}
1017
1018	return irq;
1019}
1020
1021static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin,
1022			     unsigned int flags, struct irq_alloc_info *info)
1023{
1024	int irq;
1025	bool legacy = false;
1026	struct irq_alloc_info tmp;
1027	struct mp_chip_data *data;
1028	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
1029
1030	if (!domain)
1031		return -ENOSYS;
1032
1033	if (idx >= 0 && test_bit(mp_irqs[idx].srcbus, mp_bus_not_pci)) {
1034		irq = mp_irqs[idx].srcbusirq;
1035		legacy = mp_is_legacy_irq(irq);
1036	}
1037
1038	mutex_lock(&ioapic_mutex);
1039	if (!(flags & IOAPIC_MAP_ALLOC)) {
1040		if (!legacy) {
1041			irq = irq_find_mapping(domain, pin);
1042			if (irq == 0)
1043				irq = -ENOENT;
1044		}
1045	} else {
1046		ioapic_copy_alloc_attr(&tmp, info, gsi, ioapic, pin);
1047		if (legacy)
1048			irq = alloc_isa_irq_from_domain(domain, irq,
1049							ioapic, pin, &tmp);
1050		else if ((irq = irq_find_mapping(domain, pin)) == 0)
1051			irq = alloc_irq_from_domain(domain, ioapic, gsi, &tmp);
1052		else if (!mp_check_pin_attr(irq, &tmp))
1053			irq = -EBUSY;
1054		if (irq >= 0) {
1055			data = irq_get_chip_data(irq);
1056			data->count++;
1057		}
1058	}
1059	mutex_unlock(&ioapic_mutex);
1060
1061	return irq;
1062}
1063
1064static int pin_2_irq(int idx, int ioapic, int pin, unsigned int flags)
1065{
1066	u32 gsi = mp_pin_to_gsi(ioapic, pin);
1067
1068	/*
1069	 * Debugging check, we are in big trouble if this message pops up!
1070	 */
1071	if (mp_irqs[idx].dstirq != pin)
1072		pr_err("broken BIOS or MPTABLE parser, ayiee!!\n");
1073
1074#ifdef CONFIG_X86_32
1075	/*
1076	 * PCI IRQ command line redirection. Yes, limits are hardcoded.
1077	 */
1078	if ((pin >= 16) && (pin <= 23)) {
1079		if (pirq_entries[pin-16] != -1) {
1080			if (!pirq_entries[pin-16]) {
1081				apic_printk(APIC_VERBOSE, KERN_DEBUG
1082						"disabling PIRQ%d\n", pin-16);
1083			} else {
1084				int irq = pirq_entries[pin-16];
1085				apic_printk(APIC_VERBOSE, KERN_DEBUG
1086						"using PIRQ%d -> IRQ %d\n",
1087						pin-16, irq);
1088				return irq;
1089			}
1090		}
1091	}
1092#endif
1093
1094	return  mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, NULL);
1095}
1096
1097int mp_map_gsi_to_irq(u32 gsi, unsigned int flags, struct irq_alloc_info *info)
1098{
1099	int ioapic, pin, idx;
1100
1101	ioapic = mp_find_ioapic(gsi);
1102	if (ioapic < 0)
1103		return -ENODEV;
1104
1105	pin = mp_find_ioapic_pin(ioapic, gsi);
1106	idx = find_irq_entry(ioapic, pin, mp_INT);
1107	if ((flags & IOAPIC_MAP_CHECK) && idx < 0)
1108		return -ENODEV;
1109
1110	return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, info);
1111}
1112
1113void mp_unmap_irq(int irq)
1114{
1115	struct irq_data *irq_data = irq_get_irq_data(irq);
1116	struct mp_chip_data *data;
1117
1118	if (!irq_data || !irq_data->domain)
1119		return;
1120
1121	data = irq_data->chip_data;
1122	if (!data || data->isa_irq)
1123		return;
1124
1125	mutex_lock(&ioapic_mutex);
1126	if (--data->count == 0)
1127		irq_domain_free_irqs(irq, 1);
1128	mutex_unlock(&ioapic_mutex);
1129}
1130
1131/*
1132 * Find a specific PCI IRQ entry.
1133 * Not an __init, possibly needed by modules
1134 */
1135int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin)
1136{
1137	int irq, i, best_ioapic = -1, best_idx = -1;
1138
1139	apic_printk(APIC_DEBUG,
1140		    "querying PCI -> IRQ mapping bus:%d, slot:%d, pin:%d.\n",
1141		    bus, slot, pin);
1142	if (test_bit(bus, mp_bus_not_pci)) {
1143		apic_printk(APIC_VERBOSE,
1144			    "PCI BIOS passed nonexistent PCI bus %d!\n", bus);
1145		return -1;
1146	}
1147
1148	for (i = 0; i < mp_irq_entries; i++) {
1149		int lbus = mp_irqs[i].srcbus;
1150		int ioapic_idx, found = 0;
1151
1152		if (bus != lbus || mp_irqs[i].irqtype != mp_INT ||
1153		    slot != ((mp_irqs[i].srcbusirq >> 2) & 0x1f))
1154			continue;
1155
1156		for_each_ioapic(ioapic_idx)
1157			if (mpc_ioapic_id(ioapic_idx) == mp_irqs[i].dstapic ||
1158			    mp_irqs[i].dstapic == MP_APIC_ALL) {
1159				found = 1;
1160				break;
1161			}
1162		if (!found)
1163			continue;
1164
1165		/* Skip ISA IRQs */
1166		irq = pin_2_irq(i, ioapic_idx, mp_irqs[i].dstirq, 0);
1167		if (irq > 0 && !IO_APIC_IRQ(irq))
1168			continue;
1169
1170		if (pin == (mp_irqs[i].srcbusirq & 3)) {
1171			best_idx = i;
1172			best_ioapic = ioapic_idx;
1173			goto out;
1174		}
1175
1176		/*
1177		 * Use the first all-but-pin matching entry as a
1178		 * best-guess fuzzy result for broken mptables.
1179		 */
1180		if (best_idx < 0) {
1181			best_idx = i;
1182			best_ioapic = ioapic_idx;
1183		}
1184	}
1185	if (best_idx < 0)
1186		return -1;
1187
1188out:
1189	return pin_2_irq(best_idx, best_ioapic, mp_irqs[best_idx].dstirq,
1190			 IOAPIC_MAP_ALLOC);
1191}
1192EXPORT_SYMBOL(IO_APIC_get_PCI_irq_vector);
1193
1194static struct irq_chip ioapic_chip, ioapic_ir_chip;
1195
1196static void __init setup_IO_APIC_irqs(void)
1197{
1198	unsigned int ioapic, pin;
1199	int idx;
1200
1201	apic_printk(APIC_VERBOSE, KERN_DEBUG "init IO_APIC IRQs\n");
1202
1203	for_each_ioapic_pin(ioapic, pin) {
1204		idx = find_irq_entry(ioapic, pin, mp_INT);
1205		if (idx < 0)
1206			apic_printk(APIC_VERBOSE,
1207				    KERN_DEBUG " apic %d pin %d not connected\n",
1208				    mpc_ioapic_id(ioapic), pin);
1209		else
1210			pin_2_irq(idx, ioapic, pin,
1211				  ioapic ? 0 : IOAPIC_MAP_ALLOC);
1212	}
1213}
1214
1215void ioapic_zap_locks(void)
1216{
1217	raw_spin_lock_init(&ioapic_lock);
1218}
1219
1220static void io_apic_print_entries(unsigned int apic, unsigned int nr_entries)
1221{
1222	int i;
1223	char buf[256];
1224	struct IO_APIC_route_entry entry;
1225	struct IR_IO_APIC_route_entry *ir_entry = (void *)&entry;
1226
1227	printk(KERN_DEBUG "IOAPIC %d:\n", apic);
1228	for (i = 0; i <= nr_entries; i++) {
1229		entry = ioapic_read_entry(apic, i);
1230		snprintf(buf, sizeof(buf),
1231			 " pin%02x, %s, %s, %s, V(%02X), IRR(%1d), S(%1d)",
1232			 i,
1233			 entry.mask == IOAPIC_MASKED ? "disabled" : "enabled ",
1234			 entry.trigger == IOAPIC_LEVEL ? "level" : "edge ",
1235			 entry.polarity == IOAPIC_POL_LOW ? "low " : "high",
1236			 entry.vector, entry.irr, entry.delivery_status);
1237		if (ir_entry->format)
1238			printk(KERN_DEBUG "%s, remapped, I(%04X),  Z(%X)\n",
1239			       buf, (ir_entry->index2 << 15) | ir_entry->index,
1240			       ir_entry->zero);
1241		else
1242			printk(KERN_DEBUG "%s, %s, D(%02X), M(%1d)\n",
1243			       buf,
1244			       entry.dest_mode == IOAPIC_DEST_MODE_LOGICAL ?
1245			       "logical " : "physical",
1246			       entry.dest, entry.delivery_mode);
1247	}
1248}
1249
1250static void __init print_IO_APIC(int ioapic_idx)
1251{
1252	union IO_APIC_reg_00 reg_00;
1253	union IO_APIC_reg_01 reg_01;
1254	union IO_APIC_reg_02 reg_02;
1255	union IO_APIC_reg_03 reg_03;
1256	unsigned long flags;
1257
1258	raw_spin_lock_irqsave(&ioapic_lock, flags);
1259	reg_00.raw = io_apic_read(ioapic_idx, 0);
1260	reg_01.raw = io_apic_read(ioapic_idx, 1);
1261	if (reg_01.bits.version >= 0x10)
1262		reg_02.raw = io_apic_read(ioapic_idx, 2);
1263	if (reg_01.bits.version >= 0x20)
1264		reg_03.raw = io_apic_read(ioapic_idx, 3);
1265	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1266
1267	printk(KERN_DEBUG "IO APIC #%d......\n", mpc_ioapic_id(ioapic_idx));
1268	printk(KERN_DEBUG ".... register #00: %08X\n", reg_00.raw);
1269	printk(KERN_DEBUG ".......    : physical APIC id: %02X\n", reg_00.bits.ID);
1270	printk(KERN_DEBUG ".......    : Delivery Type: %X\n", reg_00.bits.delivery_type);
1271	printk(KERN_DEBUG ".......    : LTS          : %X\n", reg_00.bits.LTS);
1272
1273	printk(KERN_DEBUG ".... register #01: %08X\n", *(int *)&reg_01);
1274	printk(KERN_DEBUG ".......     : max redirection entries: %02X\n",
1275		reg_01.bits.entries);
1276
1277	printk(KERN_DEBUG ".......     : PRQ implemented: %X\n", reg_01.bits.PRQ);
1278	printk(KERN_DEBUG ".......     : IO APIC version: %02X\n",
1279		reg_01.bits.version);
1280
1281	/*
1282	 * Some Intel chipsets with IO APIC VERSION of 0x1? don't have reg_02,
1283	 * but the value of reg_02 is read as the previous read register
1284	 * value, so ignore it if reg_02 == reg_01.
1285	 */
1286	if (reg_01.bits.version >= 0x10 && reg_02.raw != reg_01.raw) {
1287		printk(KERN_DEBUG ".... register #02: %08X\n", reg_02.raw);
1288		printk(KERN_DEBUG ".......     : arbitration: %02X\n", reg_02.bits.arbitration);
1289	}
1290
1291	/*
1292	 * Some Intel chipsets with IO APIC VERSION of 0x2? don't have reg_02
1293	 * or reg_03, but the value of reg_0[23] is read as the previous read
1294	 * register value, so ignore it if reg_03 == reg_0[12].
1295	 */
1296	if (reg_01.bits.version >= 0x20 && reg_03.raw != reg_02.raw &&
1297	    reg_03.raw != reg_01.raw) {
1298		printk(KERN_DEBUG ".... register #03: %08X\n", reg_03.raw);
1299		printk(KERN_DEBUG ".......     : Boot DT    : %X\n", reg_03.bits.boot_DT);
1300	}
1301
1302	printk(KERN_DEBUG ".... IRQ redirection table:\n");
1303	io_apic_print_entries(ioapic_idx, reg_01.bits.entries);
1304}
1305
1306void __init print_IO_APICs(void)
1307{
1308	int ioapic_idx;
1309	unsigned int irq;
1310
1311	printk(KERN_DEBUG "number of MP IRQ sources: %d.\n", mp_irq_entries);
1312	for_each_ioapic(ioapic_idx)
1313		printk(KERN_DEBUG "number of IO-APIC #%d registers: %d.\n",
1314		       mpc_ioapic_id(ioapic_idx),
1315		       ioapics[ioapic_idx].nr_registers);
1316
1317	/*
1318	 * We are a bit conservative about what we expect.  We have to
1319	 * know about every hardware change ASAP.
1320	 */
1321	printk(KERN_INFO "testing the IO APIC.......................\n");
1322
1323	for_each_ioapic(ioapic_idx)
1324		print_IO_APIC(ioapic_idx);
1325
1326	printk(KERN_DEBUG "IRQ to pin mappings:\n");
1327	for_each_active_irq(irq) {
1328		struct irq_pin_list *entry;
1329		struct irq_chip *chip;
1330		struct mp_chip_data *data;
1331
1332		chip = irq_get_chip(irq);
1333		if (chip != &ioapic_chip && chip != &ioapic_ir_chip)
1334			continue;
1335		data = irq_get_chip_data(irq);
1336		if (!data)
1337			continue;
1338		if (list_empty(&data->irq_2_pin))
1339			continue;
1340
1341		printk(KERN_DEBUG "IRQ%d ", irq);
1342		for_each_irq_pin(entry, data->irq_2_pin)
1343			pr_cont("-> %d:%d", entry->apic, entry->pin);
1344		pr_cont("\n");
1345	}
1346
1347	printk(KERN_INFO ".................................... done.\n");
1348}
1349
1350/* Where if anywhere is the i8259 connect in external int mode */
1351static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
1352
1353void __init enable_IO_APIC(void)
1354{
1355	int i8259_apic, i8259_pin;
1356	int apic, pin;
1357
1358	if (skip_ioapic_setup)
1359		nr_ioapics = 0;
1360
1361	if (!nr_legacy_irqs() || !nr_ioapics)
1362		return;
1363
1364	for_each_ioapic_pin(apic, pin) {
1365		/* See if any of the pins is in ExtINT mode */
1366		struct IO_APIC_route_entry entry = ioapic_read_entry(apic, pin);
1367
1368		/* If the interrupt line is enabled and in ExtInt mode
1369		 * I have found the pin where the i8259 is connected.
1370		 */
1371		if ((entry.mask == 0) && (entry.delivery_mode == dest_ExtINT)) {
1372			ioapic_i8259.apic = apic;
1373			ioapic_i8259.pin  = pin;
1374			goto found_i8259;
1375		}
1376	}
1377 found_i8259:
1378	/* Look to see what if the MP table has reported the ExtINT */
1379	/* If we could not find the appropriate pin by looking at the ioapic
1380	 * the i8259 probably is not connected the ioapic but give the
1381	 * mptable a chance anyway.
1382	 */
1383	i8259_pin  = find_isa_irq_pin(0, mp_ExtINT);
1384	i8259_apic = find_isa_irq_apic(0, mp_ExtINT);
1385	/* Trust the MP table if nothing is setup in the hardware */
1386	if ((ioapic_i8259.pin == -1) && (i8259_pin >= 0)) {
1387		printk(KERN_WARNING "ExtINT not setup in hardware but reported by MP table\n");
1388		ioapic_i8259.pin  = i8259_pin;
1389		ioapic_i8259.apic = i8259_apic;
1390	}
1391	/* Complain if the MP table and the hardware disagree */
1392	if (((ioapic_i8259.apic != i8259_apic) || (ioapic_i8259.pin != i8259_pin)) &&
1393		(i8259_pin >= 0) && (ioapic_i8259.pin >= 0))
1394	{
1395		printk(KERN_WARNING "ExtINT in hardware and MP table differ\n");
1396	}
1397
1398	/*
1399	 * Do not trust the IO-APIC being empty at bootup
1400	 */
1401	clear_IO_APIC();
1402}
1403
1404void native_restore_boot_irq_mode(void)
1405{
1406	/*
1407	 * If the i8259 is routed through an IOAPIC
1408	 * Put that IOAPIC in virtual wire mode
1409	 * so legacy interrupts can be delivered.
1410	 */
1411	if (ioapic_i8259.pin != -1) {
1412		struct IO_APIC_route_entry entry;
1413
1414		memset(&entry, 0, sizeof(entry));
1415		entry.mask		= IOAPIC_UNMASKED;
1416		entry.trigger		= IOAPIC_EDGE;
1417		entry.polarity		= IOAPIC_POL_HIGH;
1418		entry.dest_mode		= IOAPIC_DEST_MODE_PHYSICAL;
1419		entry.delivery_mode	= dest_ExtINT;
1420		entry.dest		= read_apic_id();
1421
1422		/*
1423		 * Add it to the IO-APIC irq-routing table:
1424		 */
1425		ioapic_write_entry(ioapic_i8259.apic, ioapic_i8259.pin, entry);
1426	}
1427
1428	if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
1429		disconnect_bsp_APIC(ioapic_i8259.pin != -1);
1430}
1431
1432void restore_boot_irq_mode(void)
1433{
1434	if (!nr_legacy_irqs())
1435		return;
1436
1437	x86_apic_ops.restore();
1438}
1439
1440#ifdef CONFIG_X86_32
1441/*
1442 * function to set the IO-APIC physical IDs based on the
1443 * values stored in the MPC table.
1444 *
1445 * by Matt Domsch <Matt_Domsch@dell.com>  Tue Dec 21 12:25:05 CST 1999
1446 */
1447void __init setup_ioapic_ids_from_mpc_nocheck(void)
1448{
1449	union IO_APIC_reg_00 reg_00;
1450	physid_mask_t phys_id_present_map;
1451	int ioapic_idx;
1452	int i;
1453	unsigned char old_id;
1454	unsigned long flags;
1455
1456	/*
1457	 * This is broken; anything with a real cpu count has to
1458	 * circumvent this idiocy regardless.
1459	 */
1460	apic->ioapic_phys_id_map(&phys_cpu_present_map, &phys_id_present_map);
1461
1462	/*
1463	 * Set the IOAPIC ID to the value stored in the MPC table.
1464	 */
1465	for_each_ioapic(ioapic_idx) {
1466		/* Read the register 0 value */
1467		raw_spin_lock_irqsave(&ioapic_lock, flags);
1468		reg_00.raw = io_apic_read(ioapic_idx, 0);
1469		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1470
1471		old_id = mpc_ioapic_id(ioapic_idx);
1472
1473		if (mpc_ioapic_id(ioapic_idx) >= get_physical_broadcast()) {
1474			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID is %d in the MPC table!...\n",
1475				ioapic_idx, mpc_ioapic_id(ioapic_idx));
1476			printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
1477				reg_00.bits.ID);
1478			ioapics[ioapic_idx].mp_config.apicid = reg_00.bits.ID;
1479		}
1480
1481		/*
1482		 * Sanity check, is the ID really free? Every APIC in a
1483		 * system must have a unique ID or we get lots of nice
1484		 * 'stuck on smp_invalidate_needed IPI wait' messages.
1485		 */
1486		if (apic->check_apicid_used(&phys_id_present_map,
1487					    mpc_ioapic_id(ioapic_idx))) {
1488			printk(KERN_ERR "BIOS bug, IO-APIC#%d ID %d is already used!...\n",
1489				ioapic_idx, mpc_ioapic_id(ioapic_idx));
1490			for (i = 0; i < get_physical_broadcast(); i++)
1491				if (!physid_isset(i, phys_id_present_map))
1492					break;
1493			if (i >= get_physical_broadcast())
1494				panic("Max APIC ID exceeded!\n");
1495			printk(KERN_ERR "... fixing up to %d. (tell your hw vendor)\n",
1496				i);
1497			physid_set(i, phys_id_present_map);
1498			ioapics[ioapic_idx].mp_config.apicid = i;
1499		} else {
1500			physid_mask_t tmp;
1501			apic->apicid_to_cpu_present(mpc_ioapic_id(ioapic_idx),
1502						    &tmp);
1503			apic_printk(APIC_VERBOSE, "Setting %d in the "
1504					"phys_id_present_map\n",
1505					mpc_ioapic_id(ioapic_idx));
1506			physids_or(phys_id_present_map, phys_id_present_map, tmp);
1507		}
1508
1509		/*
1510		 * We need to adjust the IRQ routing table
1511		 * if the ID changed.
1512		 */
1513		if (old_id != mpc_ioapic_id(ioapic_idx))
1514			for (i = 0; i < mp_irq_entries; i++)
1515				if (mp_irqs[i].dstapic == old_id)
1516					mp_irqs[i].dstapic
1517						= mpc_ioapic_id(ioapic_idx);
1518
1519		/*
1520		 * Update the ID register according to the right value
1521		 * from the MPC table if they are different.
1522		 */
1523		if (mpc_ioapic_id(ioapic_idx) == reg_00.bits.ID)
1524			continue;
1525
1526		apic_printk(APIC_VERBOSE, KERN_INFO
1527			"...changing IO-APIC physical APIC ID to %d ...",
1528			mpc_ioapic_id(ioapic_idx));
1529
1530		reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
1531		raw_spin_lock_irqsave(&ioapic_lock, flags);
1532		io_apic_write(ioapic_idx, 0, reg_00.raw);
1533		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1534
1535		/*
1536		 * Sanity check
1537		 */
1538		raw_spin_lock_irqsave(&ioapic_lock, flags);
1539		reg_00.raw = io_apic_read(ioapic_idx, 0);
1540		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1541		if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx))
1542			pr_cont("could not set ID!\n");
1543		else
1544			apic_printk(APIC_VERBOSE, " ok.\n");
1545	}
1546}
1547
1548void __init setup_ioapic_ids_from_mpc(void)
1549{
1550
1551	if (acpi_ioapic)
1552		return;
1553	/*
1554	 * Don't check I/O APIC IDs for xAPIC systems.  They have
1555	 * no meaning without the serial APIC bus.
1556	 */
1557	if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
1558		|| APIC_XAPIC(boot_cpu_apic_version))
1559		return;
1560	setup_ioapic_ids_from_mpc_nocheck();
1561}
1562#endif
1563
1564int no_timer_check __initdata;
1565
1566static int __init notimercheck(char *s)
1567{
1568	no_timer_check = 1;
1569	return 1;
1570}
1571__setup("no_timer_check", notimercheck);
1572
1573static void __init delay_with_tsc(void)
1574{
1575	unsigned long long start, now;
1576	unsigned long end = jiffies + 4;
1577
1578	start = rdtsc();
1579
1580	/*
1581	 * We don't know the TSC frequency yet, but waiting for
1582	 * 40000000000/HZ TSC cycles is safe:
1583	 * 4 GHz == 10 jiffies
1584	 * 1 GHz == 40 jiffies
1585	 */
1586	do {
1587		rep_nop();
1588		now = rdtsc();
1589	} while ((now - start) < 40000000000ULL / HZ &&
1590		time_before_eq(jiffies, end));
1591}
1592
1593static void __init delay_without_tsc(void)
1594{
1595	unsigned long end = jiffies + 4;
1596	int band = 1;
1597
1598	/*
1599	 * We don't know any frequency yet, but waiting for
1600	 * 40940000000/HZ cycles is safe:
1601	 * 4 GHz == 10 jiffies
1602	 * 1 GHz == 40 jiffies
1603	 * 1 << 1 + 1 << 2 +...+ 1 << 11 = 4094
1604	 */
1605	do {
1606		__delay(((1U << band++) * 10000000UL) / HZ);
1607	} while (band < 12 && time_before_eq(jiffies, end));
1608}
1609
1610/*
1611 * There is a nasty bug in some older SMP boards, their mptable lies
1612 * about the timer IRQ. We do the following to work around the situation:
1613 *
1614 *	- timer IRQ defaults to IO-APIC IRQ
1615 *	- if this function detects that timer IRQs are defunct, then we fall
1616 *	  back to ISA timer IRQs
1617 */
1618static int __init timer_irq_works(void)
1619{
1620	unsigned long t1 = jiffies;
1621	unsigned long flags;
1622
1623	if (no_timer_check)
1624		return 1;
1625
1626	local_save_flags(flags);
1627	local_irq_enable();
1628
1629	if (boot_cpu_has(X86_FEATURE_TSC))
1630		delay_with_tsc();
1631	else
1632		delay_without_tsc();
1633
1634	local_irq_restore(flags);
1635
1636	/*
1637	 * Expect a few ticks at least, to be sure some possible
1638	 * glue logic does not lock up after one or two first
1639	 * ticks in a non-ExtINT mode.  Also the local APIC
1640	 * might have cached one ExtINT interrupt.  Finally, at
1641	 * least one tick may be lost due to delays.
1642	 */
1643
1644	/* jiffies wrap? */
1645	if (time_after(jiffies, t1 + 4))
1646		return 1;
1647	return 0;
1648}
1649
1650/*
1651 * In the SMP+IOAPIC case it might happen that there are an unspecified
1652 * number of pending IRQ events unhandled. These cases are very rare,
1653 * so we 'resend' these IRQs via IPIs, to the same CPU. It's much
1654 * better to do it this way as thus we do not have to be aware of
1655 * 'pending' interrupts in the IRQ path, except at this point.
1656 */
1657/*
1658 * Edge triggered needs to resend any interrupt
1659 * that was delayed but this is now handled in the device
1660 * independent code.
1661 */
1662
1663/*
1664 * Starting up a edge-triggered IO-APIC interrupt is
1665 * nasty - we need to make sure that we get the edge.
1666 * If it is already asserted for some reason, we need
1667 * return 1 to indicate that is was pending.
1668 *
1669 * This is not complete - we should be able to fake
1670 * an edge even if it isn't on the 8259A...
1671 */
1672static unsigned int startup_ioapic_irq(struct irq_data *data)
1673{
1674	int was_pending = 0, irq = data->irq;
1675	unsigned long flags;
1676
1677	raw_spin_lock_irqsave(&ioapic_lock, flags);
1678	if (irq < nr_legacy_irqs()) {
1679		legacy_pic->mask(irq);
1680		if (legacy_pic->irq_pending(irq))
1681			was_pending = 1;
1682	}
1683	__unmask_ioapic(data->chip_data);
1684	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1685
1686	return was_pending;
1687}
1688
1689atomic_t irq_mis_count;
1690
1691#ifdef CONFIG_GENERIC_PENDING_IRQ
1692static bool io_apic_level_ack_pending(struct mp_chip_data *data)
1693{
1694	struct irq_pin_list *entry;
1695	unsigned long flags;
1696
1697	raw_spin_lock_irqsave(&ioapic_lock, flags);
1698	for_each_irq_pin(entry, data->irq_2_pin) {
1699		unsigned int reg;
1700		int pin;
1701
1702		pin = entry->pin;
1703		reg = io_apic_read(entry->apic, 0x10 + pin*2);
1704		/* Is the remote IRR bit set? */
1705		if (reg & IO_APIC_REDIR_REMOTE_IRR) {
1706			raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1707			return true;
1708		}
1709	}
1710	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1711
1712	return false;
1713}
1714
1715static inline bool ioapic_prepare_move(struct irq_data *data)
1716{
1717	/* If we are moving the IRQ we need to mask it */
1718	if (unlikely(irqd_is_setaffinity_pending(data))) {
1719		if (!irqd_irq_masked(data))
1720			mask_ioapic_irq(data);
1721		return true;
1722	}
1723	return false;
1724}
1725
1726static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
1727{
1728	if (unlikely(moveit)) {
1729		/* Only migrate the irq if the ack has been received.
1730		 *
1731		 * On rare occasions the broadcast level triggered ack gets
1732		 * delayed going to ioapics, and if we reprogram the
1733		 * vector while Remote IRR is still set the irq will never
1734		 * fire again.
1735		 *
1736		 * To prevent this scenario we read the Remote IRR bit
1737		 * of the ioapic.  This has two effects.
1738		 * - On any sane system the read of the ioapic will
1739		 *   flush writes (and acks) going to the ioapic from
1740		 *   this cpu.
1741		 * - We get to see if the ACK has actually been delivered.
1742		 *
1743		 * Based on failed experiments of reprogramming the
1744		 * ioapic entry from outside of irq context starting
1745		 * with masking the ioapic entry and then polling until
1746		 * Remote IRR was clear before reprogramming the
1747		 * ioapic I don't trust the Remote IRR bit to be
1748		 * completey accurate.
1749		 *
1750		 * However there appears to be no other way to plug
1751		 * this race, so if the Remote IRR bit is not
1752		 * accurate and is causing problems then it is a hardware bug
1753		 * and you can go talk to the chipset vendor about it.
1754		 */
1755		if (!io_apic_level_ack_pending(data->chip_data))
1756			irq_move_masked_irq(data);
1757		/* If the IRQ is masked in the core, leave it: */
1758		if (!irqd_irq_masked(data))
1759			unmask_ioapic_irq(data);
1760	}
1761}
1762#else
1763static inline bool ioapic_prepare_move(struct irq_data *data)
1764{
1765	return false;
1766}
1767static inline void ioapic_finish_move(struct irq_data *data, bool moveit)
1768{
1769}
1770#endif
1771
1772static void ioapic_ack_level(struct irq_data *irq_data)
1773{
1774	struct irq_cfg *cfg = irqd_cfg(irq_data);
1775	unsigned long v;
1776	bool moveit;
1777	int i;
1778
1779	irq_complete_move(cfg);
1780	moveit = ioapic_prepare_move(irq_data);
1781
1782	/*
1783	 * It appears there is an erratum which affects at least version 0x11
1784	 * of I/O APIC (that's the 82093AA and cores integrated into various
1785	 * chipsets).  Under certain conditions a level-triggered interrupt is
1786	 * erroneously delivered as edge-triggered one but the respective IRR
1787	 * bit gets set nevertheless.  As a result the I/O unit expects an EOI
1788	 * message but it will never arrive and further interrupts are blocked
1789	 * from the source.  The exact reason is so far unknown, but the
1790	 * phenomenon was observed when two consecutive interrupt requests
1791	 * from a given source get delivered to the same CPU and the source is
1792	 * temporarily disabled in between.
1793	 *
1794	 * A workaround is to simulate an EOI message manually.  We achieve it
1795	 * by setting the trigger mode to edge and then to level when the edge
1796	 * trigger mode gets detected in the TMR of a local APIC for a
1797	 * level-triggered interrupt.  We mask the source for the time of the
1798	 * operation to prevent an edge-triggered interrupt escaping meanwhile.
1799	 * The idea is from Manfred Spraul.  --macro
1800	 *
1801	 * Also in the case when cpu goes offline, fixup_irqs() will forward
1802	 * any unhandled interrupt on the offlined cpu to the new cpu
1803	 * destination that is handling the corresponding interrupt. This
1804	 * interrupt forwarding is done via IPI's. Hence, in this case also
1805	 * level-triggered io-apic interrupt will be seen as an edge
1806	 * interrupt in the IRR. And we can't rely on the cpu's EOI
1807	 * to be broadcasted to the IO-APIC's which will clear the remoteIRR
1808	 * corresponding to the level-triggered interrupt. Hence on IO-APIC's
1809	 * supporting EOI register, we do an explicit EOI to clear the
1810	 * remote IRR and on IO-APIC's which don't have an EOI register,
1811	 * we use the above logic (mask+edge followed by unmask+level) from
1812	 * Manfred Spraul to clear the remote IRR.
1813	 */
1814	i = cfg->vector;
1815	v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
1816
1817	/*
1818	 * We must acknowledge the irq before we move it or the acknowledge will
1819	 * not propagate properly.
1820	 */
1821	ack_APIC_irq();
1822
1823	/*
1824	 * Tail end of clearing remote IRR bit (either by delivering the EOI
1825	 * message via io-apic EOI register write or simulating it using
1826	 * mask+edge followed by unnask+level logic) manually when the
1827	 * level triggered interrupt is seen as the edge triggered interrupt
1828	 * at the cpu.
1829	 */
1830	if (!(v & (1 << (i & 0x1f)))) {
1831		atomic_inc(&irq_mis_count);
1832		eoi_ioapic_pin(cfg->vector, irq_data->chip_data);
1833	}
1834
1835	ioapic_finish_move(irq_data, moveit);
1836}
1837
1838static void ioapic_ir_ack_level(struct irq_data *irq_data)
1839{
1840	struct mp_chip_data *data = irq_data->chip_data;
1841
1842	/*
1843	 * Intr-remapping uses pin number as the virtual vector
1844	 * in the RTE. Actual vector is programmed in
1845	 * intr-remapping table entry. Hence for the io-apic
1846	 * EOI we use the pin number.
1847	 */
1848	apic_ack_irq(irq_data);
1849	eoi_ioapic_pin(data->entry.vector, data);
1850}
1851
1852static void ioapic_configure_entry(struct irq_data *irqd)
1853{
1854	struct mp_chip_data *mpd = irqd->chip_data;
1855	struct irq_cfg *cfg = irqd_cfg(irqd);
1856	struct irq_pin_list *entry;
1857
1858	/*
1859	 * Only update when the parent is the vector domain, don't touch it
1860	 * if the parent is the remapping domain. Check the installed
1861	 * ioapic chip to verify that.
1862	 */
1863	if (irqd->chip == &ioapic_chip) {
1864		mpd->entry.dest = cfg->dest_apicid;
1865		mpd->entry.vector = cfg->vector;
1866	}
1867	for_each_irq_pin(entry, mpd->irq_2_pin)
1868		__ioapic_write_entry(entry->apic, entry->pin, mpd->entry);
1869}
1870
1871static int ioapic_set_affinity(struct irq_data *irq_data,
1872			       const struct cpumask *mask, bool force)
1873{
1874	struct irq_data *parent = irq_data->parent_data;
1875	unsigned long flags;
1876	int ret;
1877
1878	ret = parent->chip->irq_set_affinity(parent, mask, force);
1879	raw_spin_lock_irqsave(&ioapic_lock, flags);
1880	if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE)
1881		ioapic_configure_entry(irq_data);
1882	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
1883
1884	return ret;
1885}
1886
1887/*
1888 * Interrupt shutdown masks the ioapic pin, but the interrupt might already
1889 * be in flight, but not yet serviced by the target CPU. That means
1890 * __synchronize_hardirq() would return and claim that everything is calmed
1891 * down. So free_irq() would proceed and deactivate the interrupt and free
1892 * resources.
1893 *
1894 * Once the target CPU comes around to service it it will find a cleared
1895 * vector and complain. While the spurious interrupt is harmless, the full
1896 * release of resources might prevent the interrupt from being acknowledged
1897 * which keeps the hardware in a weird state.
1898 *
1899 * Verify that the corresponding Remote-IRR bits are clear.
1900 */
1901static int ioapic_irq_get_chip_state(struct irq_data *irqd,
1902				   enum irqchip_irq_state which,
1903				   bool *state)
1904{
1905	struct mp_chip_data *mcd = irqd->chip_data;
1906	struct IO_APIC_route_entry rentry;
1907	struct irq_pin_list *p;
1908
1909	if (which != IRQCHIP_STATE_ACTIVE)
1910		return -EINVAL;
1911
1912	*state = false;
1913	raw_spin_lock(&ioapic_lock);
1914	for_each_irq_pin(p, mcd->irq_2_pin) {
1915		rentry = __ioapic_read_entry(p->apic, p->pin);
1916		/*
1917		 * The remote IRR is only valid in level trigger mode. It's
1918		 * meaning is undefined for edge triggered interrupts and
1919		 * irrelevant because the IO-APIC treats them as fire and
1920		 * forget.
1921		 */
1922		if (rentry.irr && rentry.trigger) {
1923			*state = true;
1924			break;
1925		}
1926	}
1927	raw_spin_unlock(&ioapic_lock);
1928	return 0;
1929}
1930
1931static struct irq_chip ioapic_chip __read_mostly = {
1932	.name			= "IO-APIC",
1933	.irq_startup		= startup_ioapic_irq,
1934	.irq_mask		= mask_ioapic_irq,
1935	.irq_unmask		= unmask_ioapic_irq,
1936	.irq_ack		= irq_chip_ack_parent,
1937	.irq_eoi		= ioapic_ack_level,
1938	.irq_set_affinity	= ioapic_set_affinity,
1939	.irq_retrigger		= irq_chip_retrigger_hierarchy,
1940	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
1941	.flags			= IRQCHIP_SKIP_SET_WAKE,
1942};
1943
1944static struct irq_chip ioapic_ir_chip __read_mostly = {
1945	.name			= "IR-IO-APIC",
1946	.irq_startup		= startup_ioapic_irq,
1947	.irq_mask		= mask_ioapic_irq,
1948	.irq_unmask		= unmask_ioapic_irq,
1949	.irq_ack		= irq_chip_ack_parent,
1950	.irq_eoi		= ioapic_ir_ack_level,
1951	.irq_set_affinity	= ioapic_set_affinity,
1952	.irq_retrigger		= irq_chip_retrigger_hierarchy,
1953	.irq_get_irqchip_state	= ioapic_irq_get_chip_state,
1954	.flags			= IRQCHIP_SKIP_SET_WAKE,
1955};
1956
1957static inline void init_IO_APIC_traps(void)
1958{
1959	struct irq_cfg *cfg;
1960	unsigned int irq;
1961
1962	for_each_active_irq(irq) {
1963		cfg = irq_cfg(irq);
1964		if (IO_APIC_IRQ(irq) && cfg && !cfg->vector) {
1965			/*
1966			 * Hmm.. We don't have an entry for this,
1967			 * so default to an old-fashioned 8259
1968			 * interrupt if we can..
1969			 */
1970			if (irq < nr_legacy_irqs())
1971				legacy_pic->make_irq(irq);
1972			else
1973				/* Strange. Oh, well.. */
1974				irq_set_chip(irq, &no_irq_chip);
1975		}
1976	}
1977}
1978
1979/*
1980 * The local APIC irq-chip implementation:
1981 */
1982
1983static void mask_lapic_irq(struct irq_data *data)
1984{
1985	unsigned long v;
1986
1987	v = apic_read(APIC_LVT0);
1988	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1989}
1990
1991static void unmask_lapic_irq(struct irq_data *data)
1992{
1993	unsigned long v;
1994
1995	v = apic_read(APIC_LVT0);
1996	apic_write(APIC_LVT0, v & ~APIC_LVT_MASKED);
1997}
1998
1999static void ack_lapic_irq(struct irq_data *data)
2000{
2001	ack_APIC_irq();
2002}
2003
2004static struct irq_chip lapic_chip __read_mostly = {
2005	.name		= "local-APIC",
2006	.irq_mask	= mask_lapic_irq,
2007	.irq_unmask	= unmask_lapic_irq,
2008	.irq_ack	= ack_lapic_irq,
2009};
2010
2011static void lapic_register_intr(int irq)
2012{
2013	irq_clear_status_flags(irq, IRQ_LEVEL);
2014	irq_set_chip_and_handler_name(irq, &lapic_chip, handle_edge_irq,
2015				      "edge");
2016}
2017
2018/*
2019 * This looks a bit hackish but it's about the only one way of sending
2020 * a few INTA cycles to 8259As and any associated glue logic.  ICR does
2021 * not support the ExtINT mode, unfortunately.  We need to send these
2022 * cycles as some i82489DX-based boards have glue logic that keeps the
2023 * 8259A interrupt line asserted until INTA.  --macro
2024 */
2025static inline void __init unlock_ExtINT_logic(void)
2026{
2027	int apic, pin, i;
2028	struct IO_APIC_route_entry entry0, entry1;
2029	unsigned char save_control, save_freq_select;
2030
2031	pin  = find_isa_irq_pin(8, mp_INT);
2032	if (pin == -1) {
2033		WARN_ON_ONCE(1);
2034		return;
2035	}
2036	apic = find_isa_irq_apic(8, mp_INT);
2037	if (apic == -1) {
2038		WARN_ON_ONCE(1);
2039		return;
2040	}
2041
2042	entry0 = ioapic_read_entry(apic, pin);
2043	clear_IO_APIC_pin(apic, pin);
2044
2045	memset(&entry1, 0, sizeof(entry1));
2046
2047	entry1.dest_mode = IOAPIC_DEST_MODE_PHYSICAL;
2048	entry1.mask = IOAPIC_UNMASKED;
2049	entry1.dest = hard_smp_processor_id();
2050	entry1.delivery_mode = dest_ExtINT;
2051	entry1.polarity = entry0.polarity;
2052	entry1.trigger = IOAPIC_EDGE;
2053	entry1.vector = 0;
2054
2055	ioapic_write_entry(apic, pin, entry1);
2056
2057	save_control = CMOS_READ(RTC_CONTROL);
2058	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
2059	CMOS_WRITE((save_freq_select & ~RTC_RATE_SELECT) | 0x6,
2060		   RTC_FREQ_SELECT);
2061	CMOS_WRITE(save_control | RTC_PIE, RTC_CONTROL);
2062
2063	i = 100;
2064	while (i-- > 0) {
2065		mdelay(10);
2066		if ((CMOS_READ(RTC_INTR_FLAGS) & RTC_PF) == RTC_PF)
2067			i -= 10;
2068	}
2069
2070	CMOS_WRITE(save_control, RTC_CONTROL);
2071	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
2072	clear_IO_APIC_pin(apic, pin);
2073
2074	ioapic_write_entry(apic, pin, entry0);
2075}
2076
2077static int disable_timer_pin_1 __initdata;
2078/* Actually the next is obsolete, but keep it for paranoid reasons -AK */
2079static int __init disable_timer_pin_setup(char *arg)
2080{
2081	disable_timer_pin_1 = 1;
2082	return 0;
2083}
2084early_param("disable_timer_pin_1", disable_timer_pin_setup);
2085
2086static int mp_alloc_timer_irq(int ioapic, int pin)
2087{
2088	int irq = -1;
2089	struct irq_domain *domain = mp_ioapic_irqdomain(ioapic);
2090
2091	if (domain) {
2092		struct irq_alloc_info info;
2093
2094		ioapic_set_alloc_attr(&info, NUMA_NO_NODE, 0, 0);
2095		info.ioapic_id = mpc_ioapic_id(ioapic);
2096		info.ioapic_pin = pin;
2097		mutex_lock(&ioapic_mutex);
2098		irq = alloc_isa_irq_from_domain(domain, 0, ioapic, pin, &info);
2099		mutex_unlock(&ioapic_mutex);
2100	}
2101
2102	return irq;
2103}
2104
2105/*
2106 * This code may look a bit paranoid, but it's supposed to cooperate with
2107 * a wide range of boards and BIOS bugs.  Fortunately only the timer IRQ
2108 * is so screwy.  Thanks to Brian Perkins for testing/hacking this beast
2109 * fanatically on his truly buggy board.
2110 *
2111 * FIXME: really need to revamp this for all platforms.
2112 */
2113static inline void __init check_timer(void)
2114{
2115	struct irq_data *irq_data = irq_get_irq_data(0);
2116	struct mp_chip_data *data = irq_data->chip_data;
2117	struct irq_cfg *cfg = irqd_cfg(irq_data);
2118	int node = cpu_to_node(0);
2119	int apic1, pin1, apic2, pin2;
2120	unsigned long flags;
2121	int no_pin1 = 0;
2122
2123	if (!global_clock_event)
2124		return;
2125
2126	local_irq_save(flags);
2127
2128	/*
2129	 * get/set the timer IRQ vector:
2130	 */
2131	legacy_pic->mask(0);
2132
2133	/*
2134	 * As IRQ0 is to be enabled in the 8259A, the virtual
2135	 * wire has to be disabled in the local APIC.  Also
2136	 * timer interrupts need to be acknowledged manually in
2137	 * the 8259A for the i82489DX when using the NMI
2138	 * watchdog as that APIC treats NMIs as level-triggered.
2139	 * The AEOI mode will finish them in the 8259A
2140	 * automatically.
2141	 */
2142	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
2143	legacy_pic->init(1);
2144
2145	pin1  = find_isa_irq_pin(0, mp_INT);
2146	apic1 = find_isa_irq_apic(0, mp_INT);
2147	pin2  = ioapic_i8259.pin;
2148	apic2 = ioapic_i8259.apic;
2149
2150	apic_printk(APIC_QUIET, KERN_INFO "..TIMER: vector=0x%02X "
2151		    "apic1=%d pin1=%d apic2=%d pin2=%d\n",
2152		    cfg->vector, apic1, pin1, apic2, pin2);
2153
2154	/*
2155	 * Some BIOS writers are clueless and report the ExtINTA
2156	 * I/O APIC input from the cascaded 8259A as the timer
2157	 * interrupt input.  So just in case, if only one pin
2158	 * was found above, try it both directly and through the
2159	 * 8259A.
2160	 */
2161	if (pin1 == -1) {
2162		panic_if_irq_remap("BIOS bug: timer not connected to IO-APIC");
2163		pin1 = pin2;
2164		apic1 = apic2;
2165		no_pin1 = 1;
2166	} else if (pin2 == -1) {
2167		pin2 = pin1;
2168		apic2 = apic1;
2169	}
2170
2171	if (pin1 != -1) {
2172		/* Ok, does IRQ0 through the IOAPIC work? */
2173		if (no_pin1) {
2174			mp_alloc_timer_irq(apic1, pin1);
2175		} else {
2176			/*
2177			 * for edge trigger, it's already unmasked,
2178			 * so only need to unmask if it is level-trigger
2179			 * do we really have level trigger timer?
2180			 */
2181			int idx;
2182			idx = find_irq_entry(apic1, pin1, mp_INT);
2183			if (idx != -1 && irq_trigger(idx))
2184				unmask_ioapic_irq(irq_get_irq_data(0));
2185		}
2186		irq_domain_deactivate_irq(irq_data);
2187		irq_domain_activate_irq(irq_data, false);
2188		if (timer_irq_works()) {
2189			if (disable_timer_pin_1 > 0)
2190				clear_IO_APIC_pin(0, pin1);
2191			goto out;
2192		}
2193		panic_if_irq_remap("timer doesn't work through Interrupt-remapped IO-APIC");
2194		local_irq_disable();
2195		clear_IO_APIC_pin(apic1, pin1);
2196		if (!no_pin1)
2197			apic_printk(APIC_QUIET, KERN_ERR "..MP-BIOS bug: "
2198				    "8254 timer not connected to IO-APIC\n");
2199
2200		apic_printk(APIC_QUIET, KERN_INFO "...trying to set up timer "
2201			    "(IRQ0) through the 8259A ...\n");
2202		apic_printk(APIC_QUIET, KERN_INFO
2203			    "..... (found apic %d pin %d) ...\n", apic2, pin2);
2204		/*
2205		 * legacy devices should be connected to IO APIC #0
2206		 */
2207		replace_pin_at_irq_node(data, node, apic1, pin1, apic2, pin2);
2208		irq_domain_deactivate_irq(irq_data);
2209		irq_domain_activate_irq(irq_data, false);
2210		legacy_pic->unmask(0);
2211		if (timer_irq_works()) {
2212			apic_printk(APIC_QUIET, KERN_INFO "....... works.\n");
2213			goto out;
2214		}
2215		/*
2216		 * Cleanup, just in case ...
2217		 */
2218		local_irq_disable();
2219		legacy_pic->mask(0);
2220		clear_IO_APIC_pin(apic2, pin2);
2221		apic_printk(APIC_QUIET, KERN_INFO "....... failed.\n");
2222	}
2223
2224	apic_printk(APIC_QUIET, KERN_INFO
2225		    "...trying to set up timer as Virtual Wire IRQ...\n");
2226
2227	lapic_register_intr(0);
2228	apic_write(APIC_LVT0, APIC_DM_FIXED | cfg->vector);	/* Fixed mode */
2229	legacy_pic->unmask(0);
2230
2231	if (timer_irq_works()) {
2232		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
2233		goto out;
2234	}
2235	local_irq_disable();
2236	legacy_pic->mask(0);
2237	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | cfg->vector);
2238	apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");
2239
2240	apic_printk(APIC_QUIET, KERN_INFO
2241		    "...trying to set up timer as ExtINT IRQ...\n");
2242
2243	legacy_pic->init(0);
2244	legacy_pic->make_irq(0);
2245	apic_write(APIC_LVT0, APIC_DM_EXTINT);
2246	legacy_pic->unmask(0);
2247
2248	unlock_ExtINT_logic();
2249
2250	if (timer_irq_works()) {
2251		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
2252		goto out;
2253	}
2254	local_irq_disable();
2255	apic_printk(APIC_QUIET, KERN_INFO "..... failed :(.\n");
2256	if (apic_is_x2apic_enabled())
2257		apic_printk(APIC_QUIET, KERN_INFO
2258			    "Perhaps problem with the pre-enabled x2apic mode\n"
2259			    "Try booting with x2apic and interrupt-remapping disabled in the bios.\n");
2260	panic("IO-APIC + timer doesn't work!  Boot with apic=debug and send a "
2261		"report.  Then try booting with the 'noapic' option.\n");
2262out:
2263	local_irq_restore(flags);
2264}
2265
2266/*
2267 * Traditionally ISA IRQ2 is the cascade IRQ, and is not available
2268 * to devices.  However there may be an I/O APIC pin available for
2269 * this interrupt regardless.  The pin may be left unconnected, but
2270 * typically it will be reused as an ExtINT cascade interrupt for
2271 * the master 8259A.  In the MPS case such a pin will normally be
2272 * reported as an ExtINT interrupt in the MP table.  With ACPI
2273 * there is no provision for ExtINT interrupts, and in the absence
2274 * of an override it would be treated as an ordinary ISA I/O APIC
2275 * interrupt, that is edge-triggered and unmasked by default.  We
2276 * used to do this, but it caused problems on some systems because
2277 * of the NMI watchdog and sometimes IRQ0 of the 8254 timer using
2278 * the same ExtINT cascade interrupt to drive the local APIC of the
2279 * bootstrap processor.  Therefore we refrain from routing IRQ2 to
2280 * the I/O APIC in all cases now.  No actual device should request
2281 * it anyway.  --macro
2282 */
2283#define PIC_IRQS	(1UL << PIC_CASCADE_IR)
2284
2285static int mp_irqdomain_create(int ioapic)
2286{
2287	struct irq_alloc_info info;
2288	struct irq_domain *parent;
2289	int hwirqs = mp_ioapic_pin_count(ioapic);
2290	struct ioapic *ip = &ioapics[ioapic];
2291	struct ioapic_domain_cfg *cfg = &ip->irqdomain_cfg;
2292	struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(ioapic);
2293	struct fwnode_handle *fn;
2294	char *name = "IO-APIC";
2295
2296	if (cfg->type == IOAPIC_DOMAIN_INVALID)
2297		return 0;
2298
2299	init_irq_alloc_info(&info, NULL);
2300	info.type = X86_IRQ_ALLOC_TYPE_IOAPIC;
2301	info.ioapic_id = mpc_ioapic_id(ioapic);
2302	parent = irq_remapping_get_ir_irq_domain(&info);
2303	if (!parent)
2304		parent = x86_vector_domain;
2305	else
2306		name = "IO-APIC-IR";
2307
2308	/* Handle device tree enumerated APICs proper */
2309	if (cfg->dev) {
2310		fn = of_node_to_fwnode(cfg->dev);
2311	} else {
2312		fn = irq_domain_alloc_named_id_fwnode(name, ioapic);
2313		if (!fn)
2314			return -ENOMEM;
2315	}
2316
2317	ip->irqdomain = irq_domain_create_linear(fn, hwirqs, cfg->ops,
2318						 (void *)(long)ioapic);
2319
2320	if (!ip->irqdomain) {
2321		/* Release fw handle if it was allocated above */
2322		if (!cfg->dev)
2323			irq_domain_free_fwnode(fn);
 
2324		return -ENOMEM;
2325	}
2326
2327	ip->irqdomain->parent = parent;
2328
2329	if (cfg->type == IOAPIC_DOMAIN_LEGACY ||
2330	    cfg->type == IOAPIC_DOMAIN_STRICT)
2331		ioapic_dynirq_base = max(ioapic_dynirq_base,
2332					 gsi_cfg->gsi_end + 1);
2333
2334	return 0;
2335}
2336
2337static void ioapic_destroy_irqdomain(int idx)
2338{
2339	struct ioapic_domain_cfg *cfg = &ioapics[idx].irqdomain_cfg;
2340	struct fwnode_handle *fn = ioapics[idx].irqdomain->fwnode;
2341
2342	if (ioapics[idx].irqdomain) {
2343		irq_domain_remove(ioapics[idx].irqdomain);
2344		if (!cfg->dev)
2345			irq_domain_free_fwnode(fn);
2346		ioapics[idx].irqdomain = NULL;
2347	}
2348}
2349
2350void __init setup_IO_APIC(void)
2351{
2352	int ioapic;
2353
2354	if (skip_ioapic_setup || !nr_ioapics)
2355		return;
2356
2357	io_apic_irqs = nr_legacy_irqs() ? ~PIC_IRQS : ~0UL;
2358
2359	apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
2360	for_each_ioapic(ioapic)
2361		BUG_ON(mp_irqdomain_create(ioapic));
2362
2363	/*
2364         * Set up IO-APIC IRQ routing.
2365         */
2366	x86_init.mpparse.setup_ioapic_ids();
2367
2368	sync_Arb_IDs();
2369	setup_IO_APIC_irqs();
2370	init_IO_APIC_traps();
2371	if (nr_legacy_irqs())
2372		check_timer();
2373
2374	ioapic_initialized = 1;
2375}
2376
2377static void resume_ioapic_id(int ioapic_idx)
2378{
2379	unsigned long flags;
2380	union IO_APIC_reg_00 reg_00;
2381
2382	raw_spin_lock_irqsave(&ioapic_lock, flags);
2383	reg_00.raw = io_apic_read(ioapic_idx, 0);
2384	if (reg_00.bits.ID != mpc_ioapic_id(ioapic_idx)) {
2385		reg_00.bits.ID = mpc_ioapic_id(ioapic_idx);
2386		io_apic_write(ioapic_idx, 0, reg_00.raw);
2387	}
2388	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2389}
2390
2391static void ioapic_resume(void)
2392{
2393	int ioapic_idx;
2394
2395	for_each_ioapic_reverse(ioapic_idx)
2396		resume_ioapic_id(ioapic_idx);
2397
2398	restore_ioapic_entries();
2399}
2400
2401static struct syscore_ops ioapic_syscore_ops = {
2402	.suspend = save_ioapic_entries,
2403	.resume = ioapic_resume,
2404};
2405
2406static int __init ioapic_init_ops(void)
2407{
2408	register_syscore_ops(&ioapic_syscore_ops);
2409
2410	return 0;
2411}
2412
2413device_initcall(ioapic_init_ops);
2414
2415static int io_apic_get_redir_entries(int ioapic)
2416{
2417	union IO_APIC_reg_01	reg_01;
2418	unsigned long flags;
2419
2420	raw_spin_lock_irqsave(&ioapic_lock, flags);
2421	reg_01.raw = io_apic_read(ioapic, 1);
2422	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2423
2424	/* The register returns the maximum index redir index
2425	 * supported, which is one less than the total number of redir
2426	 * entries.
2427	 */
2428	return reg_01.bits.entries + 1;
2429}
2430
2431unsigned int arch_dynirq_lower_bound(unsigned int from)
2432{
2433	/*
2434	 * dmar_alloc_hwirq() may be called before setup_IO_APIC(), so use
2435	 * gsi_top if ioapic_dynirq_base hasn't been initialized yet.
2436	 */
2437	if (!ioapic_initialized)
2438		return gsi_top;
2439	/*
2440	 * For DT enabled machines ioapic_dynirq_base is irrelevant and not
2441	 * updated. So simply return @from if ioapic_dynirq_base == 0.
2442	 */
2443	return ioapic_dynirq_base ? : from;
2444}
2445
2446#ifdef CONFIG_X86_32
2447static int io_apic_get_unique_id(int ioapic, int apic_id)
2448{
2449	union IO_APIC_reg_00 reg_00;
2450	static physid_mask_t apic_id_map = PHYSID_MASK_NONE;
2451	physid_mask_t tmp;
2452	unsigned long flags;
2453	int i = 0;
2454
2455	/*
2456	 * The P4 platform supports up to 256 APIC IDs on two separate APIC
2457	 * buses (one for LAPICs, one for IOAPICs), where predecessors only
2458	 * supports up to 16 on one shared APIC bus.
2459	 *
2460	 * TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full
2461	 *      advantage of new APIC bus architecture.
2462	 */
2463
2464	if (physids_empty(apic_id_map))
2465		apic->ioapic_phys_id_map(&phys_cpu_present_map, &apic_id_map);
2466
2467	raw_spin_lock_irqsave(&ioapic_lock, flags);
2468	reg_00.raw = io_apic_read(ioapic, 0);
2469	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2470
2471	if (apic_id >= get_physical_broadcast()) {
2472		printk(KERN_WARNING "IOAPIC[%d]: Invalid apic_id %d, trying "
2473			"%d\n", ioapic, apic_id, reg_00.bits.ID);
2474		apic_id = reg_00.bits.ID;
2475	}
2476
2477	/*
2478	 * Every APIC in a system must have a unique ID or we get lots of nice
2479	 * 'stuck on smp_invalidate_needed IPI wait' messages.
2480	 */
2481	if (apic->check_apicid_used(&apic_id_map, apic_id)) {
2482
2483		for (i = 0; i < get_physical_broadcast(); i++) {
2484			if (!apic->check_apicid_used(&apic_id_map, i))
2485				break;
2486		}
2487
2488		if (i == get_physical_broadcast())
2489			panic("Max apic_id exceeded!\n");
2490
2491		printk(KERN_WARNING "IOAPIC[%d]: apic_id %d already used, "
2492			"trying %d\n", ioapic, apic_id, i);
2493
2494		apic_id = i;
2495	}
2496
2497	apic->apicid_to_cpu_present(apic_id, &tmp);
2498	physids_or(apic_id_map, apic_id_map, tmp);
2499
2500	if (reg_00.bits.ID != apic_id) {
2501		reg_00.bits.ID = apic_id;
2502
2503		raw_spin_lock_irqsave(&ioapic_lock, flags);
2504		io_apic_write(ioapic, 0, reg_00.raw);
2505		reg_00.raw = io_apic_read(ioapic, 0);
2506		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2507
2508		/* Sanity check */
2509		if (reg_00.bits.ID != apic_id) {
2510			pr_err("IOAPIC[%d]: Unable to change apic_id!\n",
2511			       ioapic);
2512			return -1;
2513		}
2514	}
2515
2516	apic_printk(APIC_VERBOSE, KERN_INFO
2517			"IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id);
2518
2519	return apic_id;
2520}
2521
2522static u8 io_apic_unique_id(int idx, u8 id)
2523{
2524	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
2525	    !APIC_XAPIC(boot_cpu_apic_version))
2526		return io_apic_get_unique_id(idx, id);
2527	else
2528		return id;
2529}
2530#else
2531static u8 io_apic_unique_id(int idx, u8 id)
2532{
2533	union IO_APIC_reg_00 reg_00;
2534	DECLARE_BITMAP(used, 256);
2535	unsigned long flags;
2536	u8 new_id;
2537	int i;
2538
2539	bitmap_zero(used, 256);
2540	for_each_ioapic(i)
2541		__set_bit(mpc_ioapic_id(i), used);
2542
2543	/* Hand out the requested id if available */
2544	if (!test_bit(id, used))
2545		return id;
2546
2547	/*
2548	 * Read the current id from the ioapic and keep it if
2549	 * available.
2550	 */
2551	raw_spin_lock_irqsave(&ioapic_lock, flags);
2552	reg_00.raw = io_apic_read(idx, 0);
2553	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2554	new_id = reg_00.bits.ID;
2555	if (!test_bit(new_id, used)) {
2556		apic_printk(APIC_VERBOSE, KERN_INFO
2557			"IOAPIC[%d]: Using reg apic_id %d instead of %d\n",
2558			 idx, new_id, id);
2559		return new_id;
2560	}
2561
2562	/*
2563	 * Get the next free id and write it to the ioapic.
2564	 */
2565	new_id = find_first_zero_bit(used, 256);
2566	reg_00.bits.ID = new_id;
2567	raw_spin_lock_irqsave(&ioapic_lock, flags);
2568	io_apic_write(idx, 0, reg_00.raw);
2569	reg_00.raw = io_apic_read(idx, 0);
2570	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2571	/* Sanity check */
2572	BUG_ON(reg_00.bits.ID != new_id);
2573
2574	return new_id;
2575}
2576#endif
2577
2578static int io_apic_get_version(int ioapic)
2579{
2580	union IO_APIC_reg_01	reg_01;
2581	unsigned long flags;
2582
2583	raw_spin_lock_irqsave(&ioapic_lock, flags);
2584	reg_01.raw = io_apic_read(ioapic, 1);
2585	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
2586
2587	return reg_01.bits.version;
2588}
2589
2590int acpi_get_override_irq(u32 gsi, int *trigger, int *polarity)
2591{
2592	int ioapic, pin, idx;
2593
2594	if (skip_ioapic_setup)
2595		return -1;
2596
2597	ioapic = mp_find_ioapic(gsi);
2598	if (ioapic < 0)
2599		return -1;
2600
2601	pin = mp_find_ioapic_pin(ioapic, gsi);
2602	if (pin < 0)
2603		return -1;
2604
2605	idx = find_irq_entry(ioapic, pin, mp_INT);
2606	if (idx < 0)
2607		return -1;
2608
2609	*trigger = irq_trigger(idx);
2610	*polarity = irq_polarity(idx);
2611	return 0;
2612}
2613
2614/*
2615 * This function updates target affinity of IOAPIC interrupts to include
2616 * the CPUs which came online during SMP bringup.
2617 */
2618#define IOAPIC_RESOURCE_NAME_SIZE 11
2619
2620static struct resource *ioapic_resources;
2621
2622static struct resource * __init ioapic_setup_resources(void)
2623{
2624	unsigned long n;
2625	struct resource *res;
2626	char *mem;
2627	int i;
2628
2629	if (nr_ioapics == 0)
2630		return NULL;
2631
2632	n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
2633	n *= nr_ioapics;
2634
2635	mem = memblock_alloc(n, SMP_CACHE_BYTES);
2636	if (!mem)
2637		panic("%s: Failed to allocate %lu bytes\n", __func__, n);
2638	res = (void *)mem;
2639
2640	mem += sizeof(struct resource) * nr_ioapics;
2641
2642	for_each_ioapic(i) {
2643		res[i].name = mem;
2644		res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
2645		snprintf(mem, IOAPIC_RESOURCE_NAME_SIZE, "IOAPIC %u", i);
2646		mem += IOAPIC_RESOURCE_NAME_SIZE;
2647		ioapics[i].iomem_res = &res[i];
2648	}
2649
2650	ioapic_resources = res;
2651
2652	return res;
2653}
2654
2655void __init io_apic_init_mappings(void)
2656{
2657	unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
2658	struct resource *ioapic_res;
2659	int i;
2660
2661	ioapic_res = ioapic_setup_resources();
2662	for_each_ioapic(i) {
2663		if (smp_found_config) {
2664			ioapic_phys = mpc_ioapic_addr(i);
2665#ifdef CONFIG_X86_32
2666			if (!ioapic_phys) {
2667				printk(KERN_ERR
2668				       "WARNING: bogus zero IO-APIC "
2669				       "address found in MPTABLE, "
2670				       "disabling IO/APIC support!\n");
2671				smp_found_config = 0;
2672				skip_ioapic_setup = 1;
2673				goto fake_ioapic_page;
2674			}
2675#endif
2676		} else {
2677#ifdef CONFIG_X86_32
2678fake_ioapic_page:
2679#endif
2680			ioapic_phys = (unsigned long)memblock_alloc(PAGE_SIZE,
2681								    PAGE_SIZE);
2682			if (!ioapic_phys)
2683				panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
2684				      __func__, PAGE_SIZE, PAGE_SIZE);
2685			ioapic_phys = __pa(ioapic_phys);
2686		}
2687		set_fixmap_nocache(idx, ioapic_phys);
2688		apic_printk(APIC_VERBOSE, "mapped IOAPIC to %08lx (%08lx)\n",
2689			__fix_to_virt(idx) + (ioapic_phys & ~PAGE_MASK),
2690			ioapic_phys);
2691		idx++;
2692
2693		ioapic_res->start = ioapic_phys;
2694		ioapic_res->end = ioapic_phys + IO_APIC_SLOT_SIZE - 1;
2695		ioapic_res++;
2696	}
2697}
2698
2699void __init ioapic_insert_resources(void)
2700{
2701	int i;
2702	struct resource *r = ioapic_resources;
2703
2704	if (!r) {
2705		if (nr_ioapics > 0)
2706			printk(KERN_ERR
2707				"IO APIC resources couldn't be allocated.\n");
2708		return;
2709	}
2710
2711	for_each_ioapic(i) {
2712		insert_resource(&iomem_resource, r);
2713		r++;
2714	}
2715}
2716
2717int mp_find_ioapic(u32 gsi)
2718{
2719	int i;
2720
2721	if (nr_ioapics == 0)
2722		return -1;
2723
2724	/* Find the IOAPIC that manages this GSI. */
2725	for_each_ioapic(i) {
2726		struct mp_ioapic_gsi *gsi_cfg = mp_ioapic_gsi_routing(i);
2727		if (gsi >= gsi_cfg->gsi_base && gsi <= gsi_cfg->gsi_end)
2728			return i;
2729	}
2730
2731	printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
2732	return -1;
2733}
2734
2735int mp_find_ioapic_pin(int ioapic, u32 gsi)
2736{
2737	struct mp_ioapic_gsi *gsi_cfg;
2738
2739	if (WARN_ON(ioapic < 0))
2740		return -1;
2741
2742	gsi_cfg = mp_ioapic_gsi_routing(ioapic);
2743	if (WARN_ON(gsi > gsi_cfg->gsi_end))
2744		return -1;
2745
2746	return gsi - gsi_cfg->gsi_base;
2747}
2748
2749static int bad_ioapic_register(int idx)
2750{
2751	union IO_APIC_reg_00 reg_00;
2752	union IO_APIC_reg_01 reg_01;
2753	union IO_APIC_reg_02 reg_02;
2754
2755	reg_00.raw = io_apic_read(idx, 0);
2756	reg_01.raw = io_apic_read(idx, 1);
2757	reg_02.raw = io_apic_read(idx, 2);
2758
2759	if (reg_00.raw == -1 && reg_01.raw == -1 && reg_02.raw == -1) {
2760		pr_warn("I/O APIC 0x%x registers return all ones, skipping!\n",
2761			mpc_ioapic_addr(idx));
2762		return 1;
2763	}
2764
2765	return 0;
2766}
2767
2768static int find_free_ioapic_entry(void)
2769{
2770	int idx;
2771
2772	for (idx = 0; idx < MAX_IO_APICS; idx++)
2773		if (ioapics[idx].nr_registers == 0)
2774			return idx;
2775
2776	return MAX_IO_APICS;
2777}
2778
2779/**
2780 * mp_register_ioapic - Register an IOAPIC device
2781 * @id:		hardware IOAPIC ID
2782 * @address:	physical address of IOAPIC register area
2783 * @gsi_base:	base of GSI associated with the IOAPIC
2784 * @cfg:	configuration information for the IOAPIC
2785 */
2786int mp_register_ioapic(int id, u32 address, u32 gsi_base,
2787		       struct ioapic_domain_cfg *cfg)
2788{
2789	bool hotplug = !!ioapic_initialized;
2790	struct mp_ioapic_gsi *gsi_cfg;
2791	int idx, ioapic, entries;
2792	u32 gsi_end;
2793
2794	if (!address) {
2795		pr_warn("Bogus (zero) I/O APIC address found, skipping!\n");
2796		return -EINVAL;
2797	}
2798	for_each_ioapic(ioapic)
2799		if (ioapics[ioapic].mp_config.apicaddr == address) {
2800			pr_warn("address 0x%x conflicts with IOAPIC%d\n",
2801				address, ioapic);
2802			return -EEXIST;
2803		}
2804
2805	idx = find_free_ioapic_entry();
2806	if (idx >= MAX_IO_APICS) {
2807		pr_warn("Max # of I/O APICs (%d) exceeded (found %d), skipping\n",
2808			MAX_IO_APICS, idx);
2809		return -ENOSPC;
2810	}
2811
2812	ioapics[idx].mp_config.type = MP_IOAPIC;
2813	ioapics[idx].mp_config.flags = MPC_APIC_USABLE;
2814	ioapics[idx].mp_config.apicaddr = address;
2815
2816	set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
2817	if (bad_ioapic_register(idx)) {
2818		clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2819		return -ENODEV;
2820	}
2821
2822	ioapics[idx].mp_config.apicid = io_apic_unique_id(idx, id);
2823	ioapics[idx].mp_config.apicver = io_apic_get_version(idx);
2824
2825	/*
2826	 * Build basic GSI lookup table to facilitate gsi->io_apic lookups
2827	 * and to prevent reprogramming of IOAPIC pins (PCI GSIs).
2828	 */
2829	entries = io_apic_get_redir_entries(idx);
2830	gsi_end = gsi_base + entries - 1;
2831	for_each_ioapic(ioapic) {
2832		gsi_cfg = mp_ioapic_gsi_routing(ioapic);
2833		if ((gsi_base >= gsi_cfg->gsi_base &&
2834		     gsi_base <= gsi_cfg->gsi_end) ||
2835		    (gsi_end >= gsi_cfg->gsi_base &&
2836		     gsi_end <= gsi_cfg->gsi_end)) {
2837			pr_warn("GSI range [%u-%u] for new IOAPIC conflicts with GSI[%u-%u]\n",
2838				gsi_base, gsi_end,
2839				gsi_cfg->gsi_base, gsi_cfg->gsi_end);
2840			clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2841			return -ENOSPC;
2842		}
2843	}
2844	gsi_cfg = mp_ioapic_gsi_routing(idx);
2845	gsi_cfg->gsi_base = gsi_base;
2846	gsi_cfg->gsi_end = gsi_end;
2847
2848	ioapics[idx].irqdomain = NULL;
2849	ioapics[idx].irqdomain_cfg = *cfg;
2850
2851	/*
2852	 * If mp_register_ioapic() is called during early boot stage when
2853	 * walking ACPI/SFI/DT tables, it's too early to create irqdomain,
2854	 * we are still using bootmem allocator. So delay it to setup_IO_APIC().
2855	 */
2856	if (hotplug) {
2857		if (mp_irqdomain_create(idx)) {
2858			clear_fixmap(FIX_IO_APIC_BASE_0 + idx);
2859			return -ENOMEM;
2860		}
2861		alloc_ioapic_saved_registers(idx);
2862	}
2863
2864	if (gsi_cfg->gsi_end >= gsi_top)
2865		gsi_top = gsi_cfg->gsi_end + 1;
2866	if (nr_ioapics <= idx)
2867		nr_ioapics = idx + 1;
2868
2869	/* Set nr_registers to mark entry present */
2870	ioapics[idx].nr_registers = entries;
2871
2872	pr_info("IOAPIC[%d]: apic_id %d, version %d, address 0x%x, GSI %d-%d\n",
2873		idx, mpc_ioapic_id(idx),
2874		mpc_ioapic_ver(idx), mpc_ioapic_addr(idx),
2875		gsi_cfg->gsi_base, gsi_cfg->gsi_end);
2876
2877	return 0;
2878}
2879
2880int mp_unregister_ioapic(u32 gsi_base)
2881{
2882	int ioapic, pin;
2883	int found = 0;
2884
2885	for_each_ioapic(ioapic)
2886		if (ioapics[ioapic].gsi_config.gsi_base == gsi_base) {
2887			found = 1;
2888			break;
2889		}
2890	if (!found) {
2891		pr_warn("can't find IOAPIC for GSI %d\n", gsi_base);
2892		return -ENODEV;
2893	}
2894
2895	for_each_pin(ioapic, pin) {
2896		u32 gsi = mp_pin_to_gsi(ioapic, pin);
2897		int irq = mp_map_gsi_to_irq(gsi, 0, NULL);
2898		struct mp_chip_data *data;
2899
2900		if (irq >= 0) {
2901			data = irq_get_chip_data(irq);
2902			if (data && data->count) {
2903				pr_warn("pin%d on IOAPIC%d is still in use.\n",
2904					pin, ioapic);
2905				return -EBUSY;
2906			}
2907		}
2908	}
2909
2910	/* Mark entry not present */
2911	ioapics[ioapic].nr_registers  = 0;
2912	ioapic_destroy_irqdomain(ioapic);
2913	free_ioapic_saved_registers(ioapic);
2914	if (ioapics[ioapic].iomem_res)
2915		release_resource(ioapics[ioapic].iomem_res);
2916	clear_fixmap(FIX_IO_APIC_BASE_0 + ioapic);
2917	memset(&ioapics[ioapic], 0, sizeof(ioapics[ioapic]));
2918
2919	return 0;
2920}
2921
2922int mp_ioapic_registered(u32 gsi_base)
2923{
2924	int ioapic;
2925
2926	for_each_ioapic(ioapic)
2927		if (ioapics[ioapic].gsi_config.gsi_base == gsi_base)
2928			return 1;
2929
2930	return 0;
2931}
2932
2933static void mp_irqdomain_get_attr(u32 gsi, struct mp_chip_data *data,
2934				  struct irq_alloc_info *info)
2935{
2936	if (info && info->ioapic_valid) {
2937		data->trigger = info->ioapic_trigger;
2938		data->polarity = info->ioapic_polarity;
2939	} else if (acpi_get_override_irq(gsi, &data->trigger,
2940					 &data->polarity) < 0) {
2941		/* PCI interrupts are always active low level triggered. */
2942		data->trigger = IOAPIC_LEVEL;
2943		data->polarity = IOAPIC_POL_LOW;
2944	}
2945}
2946
2947static void mp_setup_entry(struct irq_cfg *cfg, struct mp_chip_data *data,
2948			   struct IO_APIC_route_entry *entry)
2949{
2950	memset(entry, 0, sizeof(*entry));
2951	entry->delivery_mode = apic->irq_delivery_mode;
2952	entry->dest_mode     = apic->irq_dest_mode;
2953	entry->dest	     = cfg->dest_apicid;
2954	entry->vector	     = cfg->vector;
2955	entry->trigger	     = data->trigger;
2956	entry->polarity	     = data->polarity;
2957	/*
2958	 * Mask level triggered irqs. Edge triggered irqs are masked
2959	 * by the irq core code in case they fire.
2960	 */
2961	if (data->trigger == IOAPIC_LEVEL)
2962		entry->mask = IOAPIC_MASKED;
2963	else
2964		entry->mask = IOAPIC_UNMASKED;
2965}
2966
2967int mp_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
2968		       unsigned int nr_irqs, void *arg)
2969{
2970	int ret, ioapic, pin;
2971	struct irq_cfg *cfg;
2972	struct irq_data *irq_data;
2973	struct mp_chip_data *data;
2974	struct irq_alloc_info *info = arg;
2975	unsigned long flags;
2976
2977	if (!info || nr_irqs > 1)
2978		return -EINVAL;
2979	irq_data = irq_domain_get_irq_data(domain, virq);
2980	if (!irq_data)
2981		return -EINVAL;
2982
2983	ioapic = mp_irqdomain_ioapic_idx(domain);
2984	pin = info->ioapic_pin;
2985	if (irq_find_mapping(domain, (irq_hw_number_t)pin) > 0)
2986		return -EEXIST;
2987
2988	data = kzalloc(sizeof(*data), GFP_KERNEL);
2989	if (!data)
2990		return -ENOMEM;
2991
2992	info->ioapic_entry = &data->entry;
2993	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
2994	if (ret < 0) {
2995		kfree(data);
2996		return ret;
2997	}
2998
2999	INIT_LIST_HEAD(&data->irq_2_pin);
3000	irq_data->hwirq = info->ioapic_pin;
3001	irq_data->chip = (domain->parent == x86_vector_domain) ?
3002			  &ioapic_chip : &ioapic_ir_chip;
3003	irq_data->chip_data = data;
3004	mp_irqdomain_get_attr(mp_pin_to_gsi(ioapic, pin), data, info);
3005
3006	cfg = irqd_cfg(irq_data);
3007	add_pin_to_irq_node(data, ioapic_alloc_attr_node(info), ioapic, pin);
3008
3009	local_irq_save(flags);
3010	if (info->ioapic_entry)
3011		mp_setup_entry(cfg, data, info->ioapic_entry);
3012	mp_register_handler(virq, data->trigger);
3013	if (virq < nr_legacy_irqs())
3014		legacy_pic->mask(virq);
3015	local_irq_restore(flags);
3016
3017	apic_printk(APIC_VERBOSE, KERN_DEBUG
3018		    "IOAPIC[%d]: Set routing entry (%d-%d -> 0x%x -> IRQ %d Mode:%i Active:%i Dest:%d)\n",
3019		    ioapic, mpc_ioapic_id(ioapic), pin, cfg->vector,
3020		    virq, data->trigger, data->polarity, cfg->dest_apicid);
3021
3022	return 0;
3023}
3024
3025void mp_irqdomain_free(struct irq_domain *domain, unsigned int virq,
3026		       unsigned int nr_irqs)
3027{
3028	struct irq_data *irq_data;
3029	struct mp_chip_data *data;
3030
3031	BUG_ON(nr_irqs != 1);
3032	irq_data = irq_domain_get_irq_data(domain, virq);
3033	if (irq_data && irq_data->chip_data) {
3034		data = irq_data->chip_data;
3035		__remove_pin_from_irq(data, mp_irqdomain_ioapic_idx(domain),
3036				      (int)irq_data->hwirq);
3037		WARN_ON(!list_empty(&data->irq_2_pin));
3038		kfree(irq_data->chip_data);
3039	}
3040	irq_domain_free_irqs_top(domain, virq, nr_irqs);
3041}
3042
3043int mp_irqdomain_activate(struct irq_domain *domain,
3044			  struct irq_data *irq_data, bool reserve)
3045{
3046	unsigned long flags;
3047
3048	raw_spin_lock_irqsave(&ioapic_lock, flags);
3049	ioapic_configure_entry(irq_data);
3050	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
3051	return 0;
3052}
3053
3054void mp_irqdomain_deactivate(struct irq_domain *domain,
3055			     struct irq_data *irq_data)
3056{
3057	/* It won't be called for IRQ with multiple IOAPIC pins associated */
3058	ioapic_mask_entry(mp_irqdomain_ioapic_idx(domain),
3059			  (int)irq_data->hwirq);
3060}
3061
3062int mp_irqdomain_ioapic_idx(struct irq_domain *domain)
3063{
3064	return (int)(long)domain->host_data;
3065}
3066
3067const struct irq_domain_ops mp_ioapic_irqdomain_ops = {
3068	.alloc		= mp_irqdomain_alloc,
3069	.free		= mp_irqdomain_free,
3070	.activate	= mp_irqdomain_activate,
3071	.deactivate	= mp_irqdomain_deactivate,
3072};