Linux Audio

Check our new training course

Loading...
v6.8
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *	Local APIC handling, local APIC timers
   4 *
   5 *	(c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
   6 *
   7 *	Fixes
   8 *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
   9 *					thanks to Eric Gilmore
  10 *					and Rolf G. Tews
  11 *					for testing these extensively.
  12 *	Maciej W. Rozycki	:	Various updates and fixes.
  13 *	Mikael Pettersson	:	Power Management for UP-APIC.
  14 *	Pavel Machek and
  15 *	Mikael Pettersson	:	PM converted to driver model.
  16 */
  17
  18#include <linux/perf_event.h>
  19#include <linux/kernel_stat.h>
  20#include <linux/mc146818rtc.h>
  21#include <linux/acpi_pmtmr.h>
  22#include <linux/clockchips.h>
  23#include <linux/interrupt.h>
  24#include <linux/memblock.h>
  25#include <linux/ftrace.h>
  26#include <linux/ioport.h>
  27#include <linux/export.h>
  28#include <linux/syscore_ops.h>
  29#include <linux/delay.h>
  30#include <linux/timex.h>
  31#include <linux/i8253.h>
  32#include <linux/dmar.h>
  33#include <linux/init.h>
  34#include <linux/cpu.h>
  35#include <linux/dmi.h>
  36#include <linux/smp.h>
  37#include <linux/mm.h>
  38
  39#include <xen/xen.h>
  40
  41#include <asm/trace/irq_vectors.h>
  42#include <asm/irq_remapping.h>
  43#include <asm/pc-conf-reg.h>
  44#include <asm/perf_event.h>
  45#include <asm/x86_init.h>
 
  46#include <linux/atomic.h>
  47#include <asm/barrier.h>
  48#include <asm/mpspec.h>
  49#include <asm/i8259.h>
  50#include <asm/proto.h>
  51#include <asm/traps.h>
  52#include <asm/apic.h>
  53#include <asm/acpi.h>
  54#include <asm/io_apic.h>
  55#include <asm/desc.h>
  56#include <asm/hpet.h>
  57#include <asm/mtrr.h>
  58#include <asm/time.h>
  59#include <asm/smp.h>
  60#include <asm/mce.h>
  61#include <asm/tsc.h>
  62#include <asm/hypervisor.h>
  63#include <asm/cpu_device_id.h>
  64#include <asm/intel-family.h>
  65#include <asm/irq_regs.h>
  66#include <asm/cpu.h>
  67
  68#include "local.h"
  69
  70unsigned int num_processors;
  71
  72unsigned disabled_cpus;
  73
  74/* Processor that is doing the boot up */
  75u32 boot_cpu_physical_apicid __ro_after_init = BAD_APICID;
  76EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
  77
  78u8 boot_cpu_apic_version __ro_after_init;
 
 
 
 
 
  79
  80/*
  81 * Bitmask of physically existing CPUs:
  82 */
  83physid_mask_t phys_cpu_present_map;
  84
  85/*
  86 * Processor to be disabled specified by kernel parameter
  87 * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
  88 * avoid undefined behaviour caused by sending INIT from AP to BSP.
  89 */
  90static u32 disabled_cpu_apicid __ro_after_init = BAD_APICID;
  91
  92/*
  93 * This variable controls which CPUs receive external NMIs.  By default,
  94 * external NMIs are delivered only to the BSP.
  95 */
  96static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP;
  97
  98/*
  99 * Hypervisor supports 15 bits of APIC ID in MSI Extended Destination ID
 100 */
 101static bool virt_ext_dest_id __ro_after_init;
 102
 103/* For parallel bootup. */
 104unsigned long apic_mmio_base __ro_after_init;
 105
 106static inline bool apic_accessible(void)
 107{
 108	return x2apic_mode || apic_mmio_base;
 109}
 110
 111/*
 112 * Map cpu index to physical APIC ID
 113 */
 114DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_apicid, BAD_APICID);
 
 115DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
 116EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
 
 117EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
 118
 119#ifdef CONFIG_X86_32
 
 
 
 
 
 
 
 
 
 120/* Local APIC was disabled by the BIOS and enabled by the kernel */
 121static int enabled_via_apicbase __ro_after_init;
 122
 123/*
 124 * Handle interrupt mode configuration register (IMCR).
 125 * This register controls whether the interrupt signals
 126 * that reach the BSP come from the master PIC or from the
 127 * local APIC. Before entering Symmetric I/O Mode, either
 128 * the BIOS or the operating system must switch out of
 129 * PIC Mode by changing the IMCR.
 130 */
 131static inline void imcr_pic_to_apic(void)
 132{
 
 
 133	/* NMI and 8259 INTR go through APIC */
 134	pc_conf_set(PC_CONF_MPS_IMCR, 0x01);
 135}
 136
 137static inline void imcr_apic_to_pic(void)
 138{
 
 
 139	/* NMI and 8259 INTR go directly to BSP */
 140	pc_conf_set(PC_CONF_MPS_IMCR, 0x00);
 141}
 142#endif
 143
 144/*
 145 * Knob to control our willingness to enable the local APIC.
 146 *
 147 * +1=force-enable
 148 */
 149static int force_enable_local_apic __initdata;
 150
 151/*
 152 * APIC command line parameters
 153 */
 154static int __init parse_lapic(char *arg)
 155{
 156	if (IS_ENABLED(CONFIG_X86_32) && !arg)
 157		force_enable_local_apic = 1;
 158	else if (arg && !strncmp(arg, "notscdeadline", 13))
 159		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
 160	return 0;
 161}
 162early_param("lapic", parse_lapic);
 163
 164#ifdef CONFIG_X86_64
 165static int apic_calibrate_pmtmr __initdata;
 166static __init int setup_apicpmtimer(char *s)
 167{
 168	apic_calibrate_pmtmr = 1;
 169	notsc_setup(NULL);
 170	return 1;
 171}
 172__setup("apicpmtimer", setup_apicpmtimer);
 173#endif
 174
 175static unsigned long mp_lapic_addr __ro_after_init;
 176bool apic_is_disabled __ro_after_init;
 177/* Disable local APIC timer from the kernel commandline or via dmi quirk */
 178static int disable_apic_timer __initdata;
 179/* Local APIC timer works in C2 */
 180int local_apic_timer_c2_ok __ro_after_init;
 181EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
 182
 
 
 183/*
 184 * Debug level, exported for io_apic.c
 185 */
 186int apic_verbosity __ro_after_init;
 187
 188int pic_mode __ro_after_init;
 189
 190/* Have we found an MP table */
 191int smp_found_config __ro_after_init;
 192
 193static struct resource lapic_resource = {
 194	.name = "Local APIC",
 195	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
 196};
 197
 198unsigned int lapic_timer_period = 0;
 199
 200static void apic_pm_activate(void);
 201
 
 
 202/*
 203 * Get the LAPIC version
 204 */
 205static inline int lapic_get_version(void)
 206{
 207	return GET_APIC_VERSION(apic_read(APIC_LVR));
 208}
 209
 210/*
 211 * Check, if the APIC is integrated or a separate chip
 212 */
 213static inline int lapic_is_integrated(void)
 214{
 
 
 
 215	return APIC_INTEGRATED(lapic_get_version());
 
 216}
 217
 218/*
 219 * Check, whether this is a modern or a first generation APIC
 220 */
 221static int modern_apic(void)
 222{
 223	/* AMD systems use old APIC versions, so check the CPU */
 224	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
 225	    boot_cpu_data.x86 >= 0xf)
 226		return 1;
 227
 228	/* Hygon systems use modern APIC */
 229	if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
 230		return 1;
 231
 232	return lapic_get_version() >= 0x14;
 233}
 234
 235/*
 236 * right after this call apic become NOOP driven
 237 * so apic->write/read doesn't do anything
 238 */
 239static void __init apic_disable(void)
 240{
 241	apic_install_driver(&apic_noop);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 242}
 243
 244void native_apic_icr_write(u32 low, u32 id)
 245{
 246	unsigned long flags;
 247
 248	local_irq_save(flags);
 249	apic_write(APIC_ICR2, SET_XAPIC_DEST_FIELD(id));
 250	apic_write(APIC_ICR, low);
 251	local_irq_restore(flags);
 252}
 253
 254u64 native_apic_icr_read(void)
 255{
 256	u32 icr1, icr2;
 257
 258	icr2 = apic_read(APIC_ICR2);
 259	icr1 = apic_read(APIC_ICR);
 260
 261	return icr1 | ((u64)icr2 << 32);
 262}
 263
 264#ifdef CONFIG_X86_32
 265/**
 266 * get_physical_broadcast - Get number of physical broadcast IDs
 267 */
 268int get_physical_broadcast(void)
 269{
 270	return modern_apic() ? 0xff : 0xf;
 271}
 272#endif
 273
 274/**
 275 * lapic_get_maxlvt - get the maximum number of local vector table entries
 276 */
 277int lapic_get_maxlvt(void)
 278{
 
 
 
 279	/*
 280	 * - we always have APIC integrated on 64bit mode
 281	 * - 82489DXs do not report # of LVT entries
 282	 */
 283	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
 284}
 285
 286/*
 287 * Local APIC timer
 288 */
 289
 290/* Clock divisor */
 291#define APIC_DIVISOR 16
 292#define TSC_DIVISOR  8
 293
 294/* i82489DX specific */
 295#define		I82489DX_BASE_DIVIDER		(((0x2) << 18))
 296
 297/*
 298 * This function sets up the local APIC timer, with a timeout of
 299 * 'clocks' APIC bus clock. During calibration we actually call
 300 * this function twice on the boot CPU, once with a bogus timeout
 301 * value, second time for real. The other (noncalibrating) CPUs
 302 * call this function only once, with the real, calibrated value.
 303 *
 304 * We do reads before writes even if unnecessary, to get around the
 305 * P5 APIC double write bug.
 306 */
 307static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
 308{
 309	unsigned int lvtt_value, tmp_value;
 310
 311	lvtt_value = LOCAL_TIMER_VECTOR;
 312	if (!oneshot)
 313		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
 314	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
 315		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
 316
 317	/*
 318	 * The i82489DX APIC uses bit 18 and 19 for the base divider.  This
 319	 * overlaps with bit 18 on integrated APICs, but is not documented
 320	 * in the SDM. No problem though. i82489DX equipped systems do not
 321	 * have TSC deadline timer.
 322	 */
 323	if (!lapic_is_integrated())
 324		lvtt_value |= I82489DX_BASE_DIVIDER;
 325
 326	if (!irqen)
 327		lvtt_value |= APIC_LVT_MASKED;
 328
 329	apic_write(APIC_LVTT, lvtt_value);
 330
 331	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
 332		/*
 333		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
 334		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
 335		 * According to Intel, MFENCE can do the serialization here.
 336		 */
 337		asm volatile("mfence" : : : "memory");
 
 
 338		return;
 339	}
 340
 341	/*
 342	 * Divide PICLK by 16
 343	 */
 344	tmp_value = apic_read(APIC_TDCR);
 345	apic_write(APIC_TDCR,
 346		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
 347		APIC_TDR_DIV_16);
 348
 349	if (!oneshot)
 350		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
 351}
 352
 353/*
 354 * Setup extended LVT, AMD specific
 355 *
 356 * Software should use the LVT offsets the BIOS provides.  The offsets
 357 * are determined by the subsystems using it like those for MCE
 358 * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
 359 * are supported. Beginning with family 10h at least 4 offsets are
 360 * available.
 361 *
 362 * Since the offsets must be consistent for all cores, we keep track
 363 * of the LVT offsets in software and reserve the offset for the same
 364 * vector also to be used on other cores. An offset is freed by
 365 * setting the entry to APIC_EILVT_MASKED.
 366 *
 367 * If the BIOS is right, there should be no conflicts. Otherwise a
 368 * "[Firmware Bug]: ..." error message is generated. However, if
 369 * software does not properly determines the offsets, it is not
 370 * necessarily a BIOS bug.
 371 */
 372
 373static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
 374
 375static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
 376{
 377	return (old & APIC_EILVT_MASKED)
 378		|| (new == APIC_EILVT_MASKED)
 379		|| ((new & ~APIC_EILVT_MASKED) == old);
 380}
 381
 382static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
 383{
 384	unsigned int rsvd, vector;
 385
 386	if (offset >= APIC_EILVT_NR_MAX)
 387		return ~0;
 388
 389	rsvd = atomic_read(&eilvt_offsets[offset]);
 390	do {
 391		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
 392		if (vector && !eilvt_entry_is_changeable(vector, new))
 393			/* may not change if vectors are different */
 394			return rsvd;
 395	} while (!atomic_try_cmpxchg(&eilvt_offsets[offset], &rsvd, new));
 
 396
 397	rsvd = new & ~APIC_EILVT_MASKED;
 398	if (rsvd && rsvd != vector)
 399		pr_info("LVT offset %d assigned for vector 0x%02x\n",
 400			offset, rsvd);
 401
 402	return new;
 403}
 404
 405/*
 406 * If mask=1, the LVT entry does not generate interrupts while mask=0
 407 * enables the vector. See also the BKDGs. Must be called with
 408 * preemption disabled.
 409 */
 410
 411int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
 412{
 413	unsigned long reg = APIC_EILVTn(offset);
 414	unsigned int new, old, reserved;
 415
 416	new = (mask << 16) | (msg_type << 8) | vector;
 417	old = apic_read(reg);
 418	reserved = reserve_eilvt_offset(offset, new);
 419
 420	if (reserved != new) {
 421		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
 422		       "vector 0x%x, but the register is already in use for "
 423		       "vector 0x%x on another cpu\n",
 424		       smp_processor_id(), reg, offset, new, reserved);
 425		return -EINVAL;
 426	}
 427
 428	if (!eilvt_entry_is_changeable(old, new)) {
 429		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
 430		       "vector 0x%x, but the register is already in use for "
 431		       "vector 0x%x on this cpu\n",
 432		       smp_processor_id(), reg, offset, new, old);
 433		return -EBUSY;
 434	}
 435
 436	apic_write(reg, new);
 437
 438	return 0;
 439}
 440EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
 441
 442/*
 443 * Program the next event, relative to now
 444 */
 445static int lapic_next_event(unsigned long delta,
 446			    struct clock_event_device *evt)
 447{
 448	apic_write(APIC_TMICT, delta);
 449	return 0;
 450}
 451
 452static int lapic_next_deadline(unsigned long delta,
 453			       struct clock_event_device *evt)
 454{
 455	u64 tsc;
 456
 457	/* This MSR is special and need a special fence: */
 458	weak_wrmsr_fence();
 459
 460	tsc = rdtsc();
 461	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
 462	return 0;
 463}
 464
 465static int lapic_timer_shutdown(struct clock_event_device *evt)
 466{
 467	unsigned int v;
 468
 469	/* Lapic used as dummy for broadcast ? */
 470	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
 471		return 0;
 472
 473	v = apic_read(APIC_LVTT);
 474	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
 475	apic_write(APIC_LVTT, v);
 476	apic_write(APIC_TMICT, 0);
 477	return 0;
 478}
 479
 480static inline int
 481lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
 482{
 483	/* Lapic used as dummy for broadcast ? */
 484	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
 485		return 0;
 486
 487	__setup_APIC_LVTT(lapic_timer_period, oneshot, 1);
 488	return 0;
 489}
 490
 491static int lapic_timer_set_periodic(struct clock_event_device *evt)
 492{
 493	return lapic_timer_set_periodic_oneshot(evt, false);
 494}
 495
 496static int lapic_timer_set_oneshot(struct clock_event_device *evt)
 497{
 498	return lapic_timer_set_periodic_oneshot(evt, true);
 499}
 500
 501/*
 502 * Local APIC timer broadcast function
 503 */
 504static void lapic_timer_broadcast(const struct cpumask *mask)
 505{
 506#ifdef CONFIG_SMP
 507	__apic_send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
 508#endif
 509}
 510
 511
 512/*
 513 * The local apic timer can be used for any function which is CPU local.
 514 */
 515static struct clock_event_device lapic_clockevent = {
 516	.name				= "lapic",
 517	.features			= CLOCK_EVT_FEAT_PERIODIC |
 518					  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
 519					  | CLOCK_EVT_FEAT_DUMMY,
 520	.shift				= 32,
 521	.set_state_shutdown		= lapic_timer_shutdown,
 522	.set_state_periodic		= lapic_timer_set_periodic,
 523	.set_state_oneshot		= lapic_timer_set_oneshot,
 524	.set_state_oneshot_stopped	= lapic_timer_shutdown,
 525	.set_next_event			= lapic_next_event,
 526	.broadcast			= lapic_timer_broadcast,
 527	.rating				= 100,
 528	.irq				= -1,
 529};
 530static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
 531
 532static const struct x86_cpu_id deadline_match[] __initconst = {
 533	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x2, 0x2), 0x3a), /* EP */
 534	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x4, 0x4), 0x0f), /* EX */
 535
 536	X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_X,	0x0b000020),
 537
 538	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x2, 0x2), 0x00000011),
 539	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x3, 0x3), 0x0700000e),
 540	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x4, 0x4), 0x0f00000c),
 541	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x5, 0x5), 0x0e000003),
 542
 543	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x3, 0x3), 0x01000136),
 544	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x4, 0x4), 0x02000014),
 545	X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x5, 0xf), 0),
 546
 547	X86_MATCH_INTEL_FAM6_MODEL( HASWELL,		0x22),
 548	X86_MATCH_INTEL_FAM6_MODEL( HASWELL_L,		0x20),
 549	X86_MATCH_INTEL_FAM6_MODEL( HASWELL_G,		0x17),
 550
 551	X86_MATCH_INTEL_FAM6_MODEL( BROADWELL,		0x25),
 552	X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_G,	0x17),
 553
 554	X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE_L,		0xb2),
 555	X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE,		0xb2),
 556
 557	X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE_L,		0x52),
 558	X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE,		0x52),
 559
 560	{},
 561};
 562
 563static __init bool apic_validate_deadline_timer(void)
 564{
 565	const struct x86_cpu_id *m;
 566	u32 rev;
 567
 568	if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
 569		return false;
 570	if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 571		return true;
 572
 573	m = x86_match_cpu(deadline_match);
 574	if (!m)
 575		return true;
 576
 577	rev = (u32)m->driver_data;
 578
 579	if (boot_cpu_data.microcode >= rev)
 580		return true;
 581
 582	setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
 583	pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
 584	       "please update microcode to version: 0x%x (or later)\n", rev);
 585	return false;
 586}
 587
 588/*
 589 * Setup the local APIC timer for this CPU. Copy the initialized values
 590 * of the boot CPU and register the clock event in the framework.
 591 */
 592static void setup_APIC_timer(void)
 593{
 594	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 595
 596	if (this_cpu_has(X86_FEATURE_ARAT)) {
 597		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
 598		/* Make LAPIC timer preferable over percpu HPET */
 599		lapic_clockevent.rating = 150;
 600	}
 601
 602	memcpy(levt, &lapic_clockevent, sizeof(*levt));
 603	levt->cpumask = cpumask_of(smp_processor_id());
 604
 605	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
 606		levt->name = "lapic-deadline";
 607		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
 608				    CLOCK_EVT_FEAT_DUMMY);
 609		levt->set_next_event = lapic_next_deadline;
 610		clockevents_config_and_register(levt,
 611						tsc_khz * (1000 / TSC_DIVISOR),
 612						0xF, ~0UL);
 613	} else
 614		clockevents_register_device(levt);
 615}
 616
 617/*
 618 * Install the updated TSC frequency from recalibration at the TSC
 619 * deadline clockevent devices.
 620 */
 621static void __lapic_update_tsc_freq(void *info)
 622{
 623	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 624
 625	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
 626		return;
 627
 628	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
 629}
 630
 631void lapic_update_tsc_freq(void)
 632{
 633	/*
 634	 * The clockevent device's ->mult and ->shift can both be
 635	 * changed. In order to avoid races, schedule the frequency
 636	 * update code on each CPU.
 637	 */
 638	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
 639}
 640
 641/*
 642 * In this functions we calibrate APIC bus clocks to the external timer.
 643 *
 644 * We want to do the calibration only once since we want to have local timer
 645 * irqs synchronous. CPUs connected by the same APIC bus have the very same bus
 646 * frequency.
 647 *
 648 * This was previously done by reading the PIT/HPET and waiting for a wrap
 649 * around to find out, that a tick has elapsed. I have a box, where the PIT
 650 * readout is broken, so it never gets out of the wait loop again. This was
 651 * also reported by others.
 652 *
 653 * Monitoring the jiffies value is inaccurate and the clockevents
 654 * infrastructure allows us to do a simple substitution of the interrupt
 655 * handler.
 656 *
 657 * The calibration routine also uses the pm_timer when possible, as the PIT
 658 * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
 659 * back to normal later in the boot process).
 660 */
 661
 662#define LAPIC_CAL_LOOPS		(HZ/10)
 663
 664static __initdata int lapic_cal_loops = -1;
 665static __initdata long lapic_cal_t1, lapic_cal_t2;
 666static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
 667static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
 668static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
 669
 670/*
 671 * Temporary interrupt handler and polled calibration function.
 672 */
 673static void __init lapic_cal_handler(struct clock_event_device *dev)
 674{
 675	unsigned long long tsc = 0;
 676	long tapic = apic_read(APIC_TMCCT);
 677	unsigned long pm = acpi_pm_read_early();
 678
 679	if (boot_cpu_has(X86_FEATURE_TSC))
 680		tsc = rdtsc();
 681
 682	switch (lapic_cal_loops++) {
 683	case 0:
 684		lapic_cal_t1 = tapic;
 685		lapic_cal_tsc1 = tsc;
 686		lapic_cal_pm1 = pm;
 687		lapic_cal_j1 = jiffies;
 688		break;
 689
 690	case LAPIC_CAL_LOOPS:
 691		lapic_cal_t2 = tapic;
 692		lapic_cal_tsc2 = tsc;
 693		if (pm < lapic_cal_pm1)
 694			pm += ACPI_PM_OVRRUN;
 695		lapic_cal_pm2 = pm;
 696		lapic_cal_j2 = jiffies;
 697		break;
 698	}
 699}
 700
 701static int __init
 702calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
 703{
 704	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
 705	const long pm_thresh = pm_100ms / 100;
 706	unsigned long mult;
 707	u64 res;
 708
 709#ifndef CONFIG_X86_PM_TIMER
 710	return -1;
 711#endif
 712
 713	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
 714
 715	/* Check, if the PM timer is available */
 716	if (!deltapm)
 717		return -1;
 718
 719	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
 720
 721	if (deltapm > (pm_100ms - pm_thresh) &&
 722	    deltapm < (pm_100ms + pm_thresh)) {
 723		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
 724		return 0;
 725	}
 726
 727	res = (((u64)deltapm) *  mult) >> 22;
 728	do_div(res, 1000000);
 729	pr_warn("APIC calibration not consistent "
 730		"with PM-Timer: %ldms instead of 100ms\n", (long)res);
 731
 732	/* Correct the lapic counter value */
 733	res = (((u64)(*delta)) * pm_100ms);
 734	do_div(res, deltapm);
 735	pr_info("APIC delta adjusted to PM-Timer: "
 736		"%lu (%ld)\n", (unsigned long)res, *delta);
 737	*delta = (long)res;
 738
 739	/* Correct the tsc counter value */
 740	if (boot_cpu_has(X86_FEATURE_TSC)) {
 741		res = (((u64)(*deltatsc)) * pm_100ms);
 742		do_div(res, deltapm);
 743		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
 744					  "PM-Timer: %lu (%ld)\n",
 745					(unsigned long)res, *deltatsc);
 746		*deltatsc = (long)res;
 747	}
 748
 749	return 0;
 750}
 751
 752static int __init lapic_init_clockevent(void)
 753{
 754	if (!lapic_timer_period)
 755		return -1;
 756
 757	/* Calculate the scaled math multiplication factor */
 758	lapic_clockevent.mult = div_sc(lapic_timer_period/APIC_DIVISOR,
 759					TICK_NSEC, lapic_clockevent.shift);
 760	lapic_clockevent.max_delta_ns =
 761		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
 762	lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
 763	lapic_clockevent.min_delta_ns =
 764		clockevent_delta2ns(0xF, &lapic_clockevent);
 765	lapic_clockevent.min_delta_ticks = 0xF;
 766
 767	return 0;
 768}
 769
 770bool __init apic_needs_pit(void)
 771{
 772	/*
 773	 * If the frequencies are not known, PIT is required for both TSC
 774	 * and apic timer calibration.
 775	 */
 776	if (!tsc_khz || !cpu_khz)
 777		return true;
 778
 779	/* Is there an APIC at all or is it disabled? */
 780	if (!boot_cpu_has(X86_FEATURE_APIC) || apic_is_disabled)
 781		return true;
 782
 783	/*
 784	 * If interrupt delivery mode is legacy PIC or virtual wire without
 785	 * configuration, the local APIC timer won't be set up. Make sure
 786	 * that the PIT is initialized.
 787	 */
 788	if (apic_intr_mode == APIC_PIC ||
 789	    apic_intr_mode == APIC_VIRTUAL_WIRE_NO_CONFIG)
 790		return true;
 791
 792	/* Virt guests may lack ARAT, but still have DEADLINE */
 793	if (!boot_cpu_has(X86_FEATURE_ARAT))
 794		return true;
 795
 796	/* Deadline timer is based on TSC so no further PIT action required */
 797	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
 798		return false;
 799
 800	/* APIC timer disabled? */
 801	if (disable_apic_timer)
 802		return true;
 803	/*
 804	 * The APIC timer frequency is known already, no PIT calibration
 805	 * required. If unknown, let the PIT be initialized.
 806	 */
 807	return lapic_timer_period == 0;
 808}
 809
 810static int __init calibrate_APIC_clock(void)
 811{
 812	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 813	u64 tsc_perj = 0, tsc_start = 0;
 814	unsigned long jif_start;
 815	unsigned long deltaj;
 816	long delta, deltatsc;
 817	int pm_referenced = 0;
 818
 819	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
 820		return 0;
 821
 822	/*
 823	 * Check if lapic timer has already been calibrated by platform
 824	 * specific routine, such as tsc calibration code. If so just fill
 825	 * in the clockevent structure and return.
 826	 */
 827	if (!lapic_init_clockevent()) {
 
 
 
 828		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
 829			    lapic_timer_period);
 830		/*
 831		 * Direct calibration methods must have an always running
 832		 * local APIC timer, no need for broadcast timer.
 833		 */
 
 
 834		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
 835		return 0;
 836	}
 837
 838	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
 839		    "calibrating APIC timer ...\n");
 840
 841	/*
 842	 * There are platforms w/o global clockevent devices. Instead of
 843	 * making the calibration conditional on that, use a polling based
 844	 * approach everywhere.
 845	 */
 846	local_irq_disable();
 847
 
 
 
 
 848	/*
 849	 * Setup the APIC counter to maximum. There is no way the lapic
 850	 * can underflow in the 100ms detection time frame
 851	 */
 852	__setup_APIC_LVTT(0xffffffff, 0, 0);
 853
 854	/*
 855	 * Methods to terminate the calibration loop:
 856	 *  1) Global clockevent if available (jiffies)
 857	 *  2) TSC if available and frequency is known
 858	 */
 859	jif_start = READ_ONCE(jiffies);
 860
 861	if (tsc_khz) {
 862		tsc_start = rdtsc();
 863		tsc_perj = div_u64((u64)tsc_khz * 1000, HZ);
 864	}
 865
 866	/*
 867	 * Enable interrupts so the tick can fire, if a global
 868	 * clockevent device is available
 869	 */
 870	local_irq_enable();
 871
 872	while (lapic_cal_loops <= LAPIC_CAL_LOOPS) {
 873		/* Wait for a tick to elapse */
 874		while (1) {
 875			if (tsc_khz) {
 876				u64 tsc_now = rdtsc();
 877				if ((tsc_now - tsc_start) >= tsc_perj) {
 878					tsc_start += tsc_perj;
 879					break;
 880				}
 881			} else {
 882				unsigned long jif_now = READ_ONCE(jiffies);
 883
 884				if (time_after(jif_now, jif_start)) {
 885					jif_start = jif_now;
 886					break;
 887				}
 888			}
 889			cpu_relax();
 890		}
 891
 892		/* Invoke the calibration routine */
 893		local_irq_disable();
 894		lapic_cal_handler(NULL);
 895		local_irq_enable();
 896	}
 897
 898	local_irq_disable();
 899
 
 
 
 900	/* Build delta t1-t2 as apic timer counts down */
 901	delta = lapic_cal_t1 - lapic_cal_t2;
 902	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
 903
 904	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
 905
 906	/* we trust the PM based calibration if possible */
 907	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
 908					&delta, &deltatsc);
 909
 910	lapic_timer_period = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
 911	lapic_init_clockevent();
 
 
 
 
 
 
 
 912
 913	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
 914	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
 915	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
 916		    lapic_timer_period);
 917
 918	if (boot_cpu_has(X86_FEATURE_TSC)) {
 919		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
 920			    "%ld.%04ld MHz.\n",
 921			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
 922			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
 923	}
 924
 925	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
 926		    "%u.%04u MHz.\n",
 927		    lapic_timer_period / (1000000 / HZ),
 928		    lapic_timer_period % (1000000 / HZ));
 929
 930	/*
 931	 * Do a sanity check on the APIC calibration result
 932	 */
 933	if (lapic_timer_period < (1000000 / HZ)) {
 934		local_irq_enable();
 935		pr_warn("APIC frequency too slow, disabling apic timer\n");
 936		return -1;
 937	}
 938
 939	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
 940
 941	/*
 942	 * PM timer calibration failed or not turned on so lets try APIC
 943	 * timer based calibration, if a global clockevent device is
 944	 * available.
 945	 */
 946	if (!pm_referenced && global_clock_event) {
 947		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
 948
 949		/*
 950		 * Setup the apic timer manually
 951		 */
 952		levt->event_handler = lapic_cal_handler;
 953		lapic_timer_set_periodic(levt);
 954		lapic_cal_loops = -1;
 955
 956		/* Let the interrupts run */
 957		local_irq_enable();
 958
 959		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
 960			cpu_relax();
 961
 962		/* Stop the lapic timer */
 963		local_irq_disable();
 964		lapic_timer_shutdown(levt);
 965
 966		/* Jiffies delta */
 967		deltaj = lapic_cal_j2 - lapic_cal_j1;
 968		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
 969
 970		/* Check, if the jiffies result is consistent */
 971		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
 972			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
 973		else
 974			levt->features |= CLOCK_EVT_FEAT_DUMMY;
 975	}
 976	local_irq_enable();
 977
 978	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
 979		pr_warn("APIC timer disabled due to verification failure\n");
 980		return -1;
 981	}
 982
 983	return 0;
 984}
 985
 986/*
 987 * Setup the boot APIC
 988 *
 989 * Calibrate and verify the result.
 990 */
 991void __init setup_boot_APIC_clock(void)
 992{
 993	/*
 994	 * The local apic timer can be disabled via the kernel
 995	 * commandline or from the CPU detection code. Register the lapic
 996	 * timer as a dummy clock event source on SMP systems, so the
 997	 * broadcast mechanism is used. On UP systems simply ignore it.
 998	 */
 999	if (disable_apic_timer) {
1000		pr_info("Disabling APIC timer\n");
1001		/* No broadcast on UP ! */
1002		if (num_possible_cpus() > 1) {
1003			lapic_clockevent.mult = 1;
1004			setup_APIC_timer();
1005		}
1006		return;
1007	}
1008
1009	if (calibrate_APIC_clock()) {
1010		/* No broadcast on UP ! */
1011		if (num_possible_cpus() > 1)
1012			setup_APIC_timer();
1013		return;
1014	}
1015
1016	/*
1017	 * If nmi_watchdog is set to IO_APIC, we need the
1018	 * PIT/HPET going.  Otherwise register lapic as a dummy
1019	 * device.
1020	 */
1021	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
1022
1023	/* Setup the lapic or request the broadcast */
1024	setup_APIC_timer();
1025	amd_e400_c1e_apic_setup();
1026}
1027
1028void setup_secondary_APIC_clock(void)
1029{
1030	setup_APIC_timer();
1031	amd_e400_c1e_apic_setup();
1032}
1033
1034/*
1035 * The guts of the apic timer interrupt
1036 */
1037static void local_apic_timer_interrupt(void)
1038{
1039	struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
 
1040
1041	/*
1042	 * Normally we should not be here till LAPIC has been initialized but
1043	 * in some cases like kdump, its possible that there is a pending LAPIC
1044	 * timer interrupt from previous kernel's context and is delivered in
1045	 * new kernel the moment interrupts are enabled.
1046	 *
1047	 * Interrupts are enabled early and LAPIC is setup much later, hence
1048	 * its possible that when we get here evt->event_handler is NULL.
1049	 * Check for event_handler being NULL and discard the interrupt as
1050	 * spurious.
1051	 */
1052	if (!evt->event_handler) {
1053		pr_warn("Spurious LAPIC timer interrupt on cpu %d\n",
1054			smp_processor_id());
1055		/* Switch it off */
1056		lapic_timer_shutdown(evt);
1057		return;
1058	}
1059
1060	/*
1061	 * the NMI deadlock-detector uses this.
1062	 */
1063	inc_irq_stat(apic_timer_irqs);
1064
1065	evt->event_handler(evt);
1066}
1067
1068/*
1069 * Local APIC timer interrupt. This is the most natural way for doing
1070 * local interrupts, but local timer interrupts can be emulated by
1071 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1072 *
1073 * [ if a single-CPU system runs an SMP kernel then we call the local
1074 *   interrupt as well. Thus we cannot inline the local irq ... ]
1075 */
1076DEFINE_IDTENTRY_SYSVEC(sysvec_apic_timer_interrupt)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1077{
1078	struct pt_regs *old_regs = set_irq_regs(regs);
1079
1080	apic_eoi();
 
 
 
 
 
 
 
 
1081	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1082	local_apic_timer_interrupt();
1083	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
 
1084
1085	set_irq_regs(old_regs);
1086}
1087
 
 
 
 
 
1088/*
1089 * Local APIC start and shutdown
1090 */
1091
1092/**
1093 * clear_local_APIC - shutdown the local APIC
1094 *
1095 * This is called, when a CPU is disabled and before rebooting, so the state of
1096 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1097 * leftovers during boot.
1098 */
1099void clear_local_APIC(void)
1100{
1101	int maxlvt;
1102	u32 v;
1103
1104	if (!apic_accessible())
 
1105		return;
1106
1107	maxlvt = lapic_get_maxlvt();
1108	/*
1109	 * Masking an LVT entry can trigger a local APIC error
1110	 * if the vector is zero. Mask LVTERR first to prevent this.
1111	 */
1112	if (maxlvt >= 3) {
1113		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1114		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1115	}
1116	/*
1117	 * Careful: we have to set masks only first to deassert
1118	 * any level-triggered sources.
1119	 */
1120	v = apic_read(APIC_LVTT);
1121	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1122	v = apic_read(APIC_LVT0);
1123	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1124	v = apic_read(APIC_LVT1);
1125	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1126	if (maxlvt >= 4) {
1127		v = apic_read(APIC_LVTPC);
1128		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1129	}
1130
1131	/* lets not touch this if we didn't frob it */
1132#ifdef CONFIG_X86_THERMAL_VECTOR
1133	if (maxlvt >= 5) {
1134		v = apic_read(APIC_LVTTHMR);
1135		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1136	}
1137#endif
1138#ifdef CONFIG_X86_MCE_INTEL
1139	if (maxlvt >= 6) {
1140		v = apic_read(APIC_LVTCMCI);
1141		if (!(v & APIC_LVT_MASKED))
1142			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1143	}
1144#endif
1145
1146	/*
1147	 * Clean APIC state for other OSs:
1148	 */
1149	apic_write(APIC_LVTT, APIC_LVT_MASKED);
1150	apic_write(APIC_LVT0, APIC_LVT_MASKED);
1151	apic_write(APIC_LVT1, APIC_LVT_MASKED);
1152	if (maxlvt >= 3)
1153		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1154	if (maxlvt >= 4)
1155		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1156
1157	/* Integrated APIC (!82489DX) ? */
1158	if (lapic_is_integrated()) {
1159		if (maxlvt > 3)
1160			/* Clear ESR due to Pentium errata 3AP and 11AP */
1161			apic_write(APIC_ESR, 0);
1162		apic_read(APIC_ESR);
1163	}
1164}
1165
1166/**
1167 * apic_soft_disable - Clears and software disables the local APIC on hotplug
1168 *
1169 * Contrary to disable_local_APIC() this does not touch the enable bit in
1170 * MSR_IA32_APICBASE. Clearing that bit on systems based on the 3 wire APIC
1171 * bus would require a hardware reset as the APIC would lose track of bus
1172 * arbitration. On systems with FSB delivery APICBASE could be disabled,
1173 * but it has to be guaranteed that no interrupt is sent to the APIC while
1174 * in that state and it's not clear from the SDM whether it still responds
1175 * to INIT/SIPI messages. Stay on the safe side and use software disable.
1176 */
1177void apic_soft_disable(void)
1178{
1179	u32 value;
 
 
 
 
1180
1181	clear_local_APIC();
1182
1183	/* Soft disable APIC (implies clearing of registers for 82489DX!). */
 
 
 
1184	value = apic_read(APIC_SPIV);
1185	value &= ~APIC_SPIV_APIC_ENABLED;
1186	apic_write(APIC_SPIV, value);
1187}
1188
1189/**
1190 * disable_local_APIC - clear and disable the local APIC
1191 */
1192void disable_local_APIC(void)
1193{
1194	if (!apic_accessible())
1195		return;
1196
1197	apic_soft_disable();
1198
1199#ifdef CONFIG_X86_32
1200	/*
1201	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1202	 * restore the disabled state.
1203	 */
1204	if (enabled_via_apicbase) {
1205		unsigned int l, h;
1206
1207		rdmsr(MSR_IA32_APICBASE, l, h);
1208		l &= ~MSR_IA32_APICBASE_ENABLE;
1209		wrmsr(MSR_IA32_APICBASE, l, h);
1210	}
1211#endif
1212}
1213
1214/*
1215 * If Linux enabled the LAPIC against the BIOS default disable it down before
1216 * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
1217 * not power-off.  Additionally clear all LVT entries before disable_local_APIC
1218 * for the case where Linux didn't enable the LAPIC.
1219 */
1220void lapic_shutdown(void)
1221{
1222	unsigned long flags;
1223
1224	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1225		return;
1226
1227	local_irq_save(flags);
1228
1229#ifdef CONFIG_X86_32
1230	if (!enabled_via_apicbase)
1231		clear_local_APIC();
1232	else
1233#endif
1234		disable_local_APIC();
1235
1236
1237	local_irq_restore(flags);
1238}
1239
1240/**
1241 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1242 */
1243void __init sync_Arb_IDs(void)
1244{
1245	/*
1246	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1247	 * needed on AMD.
1248	 */
1249	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1250		return;
1251
1252	/*
1253	 * Wait for idle.
1254	 */
1255	apic_wait_icr_idle();
1256
1257	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1258	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1259			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1260}
1261
1262enum apic_intr_mode_id apic_intr_mode __ro_after_init;
1263
1264static int __init __apic_intr_mode_select(void)
1265{
1266	/* Check kernel option */
1267	if (apic_is_disabled) {
1268		pr_info("APIC disabled via kernel command line\n");
1269		return APIC_PIC;
1270	}
1271
1272	/* Check BIOS */
1273#ifdef CONFIG_X86_64
1274	/* On 64-bit, the APIC must be integrated, Check local APIC only */
1275	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1276		apic_is_disabled = true;
1277		pr_info("APIC disabled by BIOS\n");
1278		return APIC_PIC;
1279	}
1280#else
1281	/* On 32-bit, the APIC may be integrated APIC or 82489DX */
1282
1283	/* Neither 82489DX nor integrated APIC ? */
1284	if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1285		apic_is_disabled = true;
1286		return APIC_PIC;
1287	}
1288
1289	/* If the BIOS pretends there is an integrated APIC ? */
1290	if (!boot_cpu_has(X86_FEATURE_APIC) &&
1291		APIC_INTEGRATED(boot_cpu_apic_version)) {
1292		apic_is_disabled = true;
1293		pr_err(FW_BUG "Local APIC not detected, force emulation\n");
1294		return APIC_PIC;
1295	}
1296#endif
1297
1298	/* Check MP table or ACPI MADT configuration */
1299	if (!smp_found_config) {
1300		disable_ioapic_support();
1301		if (!acpi_lapic) {
1302			pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1303			return APIC_VIRTUAL_WIRE_NO_CONFIG;
1304		}
1305		return APIC_VIRTUAL_WIRE;
1306	}
1307
1308#ifdef CONFIG_SMP
1309	/* If SMP should be disabled, then really disable it! */
1310	if (!setup_max_cpus) {
1311		pr_info("APIC: SMP mode deactivated\n");
1312		return APIC_SYMMETRIC_IO_NO_ROUTING;
1313	}
1314#endif
1315
1316	return APIC_SYMMETRIC_IO;
1317}
1318
1319/* Select the interrupt delivery mode for the BSP */
1320void __init apic_intr_mode_select(void)
1321{
1322	apic_intr_mode = __apic_intr_mode_select();
1323}
1324
1325/*
1326 * An initial setup of the virtual wire mode.
1327 */
1328void __init init_bsp_APIC(void)
1329{
1330	unsigned int value;
1331
1332	/*
1333	 * Don't do the setup now if we have a SMP BIOS as the
1334	 * through-I/O-APIC virtual wire mode might be active.
1335	 */
1336	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1337		return;
1338
1339	/*
1340	 * Do not trust the local APIC being empty at bootup.
1341	 */
1342	clear_local_APIC();
1343
1344	/*
1345	 * Enable APIC.
1346	 */
1347	value = apic_read(APIC_SPIV);
1348	value &= ~APIC_VECTOR_MASK;
1349	value |= APIC_SPIV_APIC_ENABLED;
1350
1351#ifdef CONFIG_X86_32
1352	/* This bit is reserved on P4/Xeon and should be cleared */
1353	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1354	    (boot_cpu_data.x86 == 15))
1355		value &= ~APIC_SPIV_FOCUS_DISABLED;
1356	else
1357#endif
1358		value |= APIC_SPIV_FOCUS_DISABLED;
1359	value |= SPURIOUS_APIC_VECTOR;
1360	apic_write(APIC_SPIV, value);
1361
1362	/*
1363	 * Set up the virtual wire mode.
1364	 */
1365	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1366	value = APIC_DM_NMI;
1367	if (!lapic_is_integrated())		/* 82489DX */
1368		value |= APIC_LVT_LEVEL_TRIGGER;
1369	if (apic_extnmi == APIC_EXTNMI_NONE)
1370		value |= APIC_LVT_MASKED;
1371	apic_write(APIC_LVT1, value);
1372}
1373
1374static void __init apic_bsp_setup(bool upmode);
1375
1376/* Init the interrupt delivery mode for the BSP */
1377void __init apic_intr_mode_init(void)
1378{
1379	bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1380
1381	switch (apic_intr_mode) {
1382	case APIC_PIC:
1383		pr_info("APIC: Keep in PIC mode(8259)\n");
1384		return;
1385	case APIC_VIRTUAL_WIRE:
1386		pr_info("APIC: Switch to virtual wire mode setup\n");
1387		break;
1388	case APIC_VIRTUAL_WIRE_NO_CONFIG:
1389		pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1390		upmode = true;
1391		break;
1392	case APIC_SYMMETRIC_IO:
1393		pr_info("APIC: Switch to symmetric I/O mode setup\n");
1394		break;
1395	case APIC_SYMMETRIC_IO_NO_ROUTING:
1396		pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1397		break;
1398	}
1399
1400	x86_64_probe_apic();
1401
1402	x86_32_install_bigsmp();
1403
1404	if (x86_platform.apic_post_init)
1405		x86_platform.apic_post_init();
1406
1407	apic_bsp_setup(upmode);
1408}
1409
1410static void lapic_setup_esr(void)
1411{
1412	unsigned int oldvalue, value, maxlvt;
1413
1414	if (!lapic_is_integrated()) {
1415		pr_info("No ESR for 82489DX.\n");
1416		return;
1417	}
1418
1419	if (apic->disable_esr) {
1420		/*
1421		 * Something untraceable is creating bad interrupts on
1422		 * secondary quads ... for the moment, just leave the
1423		 * ESR disabled - we can't do anything useful with the
1424		 * errors anyway - mbligh
1425		 */
1426		pr_info("Leaving ESR disabled.\n");
1427		return;
1428	}
1429
1430	maxlvt = lapic_get_maxlvt();
1431	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1432		apic_write(APIC_ESR, 0);
1433	oldvalue = apic_read(APIC_ESR);
1434
1435	/* enables sending errors */
1436	value = ERROR_APIC_VECTOR;
1437	apic_write(APIC_LVTERR, value);
1438
1439	/*
1440	 * spec says clear errors after enabling vector.
1441	 */
1442	if (maxlvt > 3)
1443		apic_write(APIC_ESR, 0);
1444	value = apic_read(APIC_ESR);
1445	if (value != oldvalue)
1446		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1447			"vector: 0x%08x  after: 0x%08x\n",
1448			oldvalue, value);
1449}
1450
1451#define APIC_IR_REGS		APIC_ISR_NR
1452#define APIC_IR_BITS		(APIC_IR_REGS * 32)
1453#define APIC_IR_MAPSIZE		(APIC_IR_BITS / BITS_PER_LONG)
1454
1455union apic_ir {
1456	unsigned long	map[APIC_IR_MAPSIZE];
1457	u32		regs[APIC_IR_REGS];
1458};
1459
1460static bool apic_check_and_ack(union apic_ir *irr, union apic_ir *isr)
1461{
1462	int i, bit;
1463
1464	/* Read the IRRs */
1465	for (i = 0; i < APIC_IR_REGS; i++)
1466		irr->regs[i] = apic_read(APIC_IRR + i * 0x10);
1467
1468	/* Read the ISRs */
1469	for (i = 0; i < APIC_IR_REGS; i++)
1470		isr->regs[i] = apic_read(APIC_ISR + i * 0x10);
1471
1472	/*
1473	 * If the ISR map is not empty. ACK the APIC and run another round
1474	 * to verify whether a pending IRR has been unblocked and turned
1475	 * into a ISR.
1476	 */
1477	if (!bitmap_empty(isr->map, APIC_IR_BITS)) {
1478		/*
1479		 * There can be multiple ISR bits set when a high priority
1480		 * interrupt preempted a lower priority one. Issue an ACK
1481		 * per set bit.
1482		 */
1483		for_each_set_bit(bit, isr->map, APIC_IR_BITS)
1484			apic_eoi();
1485		return true;
1486	}
1487
1488	return !bitmap_empty(irr->map, APIC_IR_BITS);
1489}
1490
1491/*
1492 * After a crash, we no longer service the interrupts and a pending
1493 * interrupt from previous kernel might still have ISR bit set.
1494 *
1495 * Most probably by now the CPU has serviced that pending interrupt and it
1496 * might not have done the apic_eoi() because it thought, interrupt
1497 * came from i8259 as ExtInt. LAPIC did not get EOI so it does not clear
1498 * the ISR bit and cpu thinks it has already serviced the interrupt. Hence
1499 * a vector might get locked. It was noticed for timer irq (vector
1500 * 0x31). Issue an extra EOI to clear ISR.
1501 *
1502 * If there are pending IRR bits they turn into ISR bits after a higher
1503 * priority ISR bit has been acked.
1504 */
1505static void apic_pending_intr_clear(void)
1506{
1507	union apic_ir irr, isr;
1508	unsigned int i;
1509
1510	/* 512 loops are way oversized and give the APIC a chance to obey. */
1511	for (i = 0; i < 512; i++) {
1512		if (!apic_check_and_ack(&irr, &isr))
1513			return;
1514	}
1515	/* Dump the IRR/ISR content if that failed */
1516	pr_warn("APIC: Stale IRR: %256pb ISR: %256pb\n", irr.map, isr.map);
1517}
1518
1519/**
1520 * setup_local_APIC - setup the local APIC
1521 *
1522 * Used to setup local APIC while initializing BSP or bringing up APs.
1523 * Always called with preemption disabled.
1524 */
1525static void setup_local_APIC(void)
1526{
1527	int cpu = smp_processor_id();
1528	unsigned int value;
 
 
 
1529
1530	if (apic_is_disabled) {
 
 
 
1531		disable_ioapic_support();
1532		return;
1533	}
1534
1535	/*
1536	 * If this comes from kexec/kcrash the APIC might be enabled in
1537	 * SPIV. Soft disable it before doing further initialization.
1538	 */
1539	value = apic_read(APIC_SPIV);
1540	value &= ~APIC_SPIV_APIC_ENABLED;
1541	apic_write(APIC_SPIV, value);
1542
1543#ifdef CONFIG_X86_32
1544	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1545	if (lapic_is_integrated() && apic->disable_esr) {
1546		apic_write(APIC_ESR, 0);
1547		apic_write(APIC_ESR, 0);
1548		apic_write(APIC_ESR, 0);
1549		apic_write(APIC_ESR, 0);
1550	}
1551#endif
1552	/* Validate that the APIC is registered if required */
1553	BUG_ON(apic->apic_id_registered && !apic->apic_id_registered());
 
 
 
 
 
1554
1555	/*
1556	 * Intel recommends to set DFR, LDR and TPR before enabling
1557	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1558	 * document number 292116).
1559	 *
1560	 * Except for APICs which operate in physical destination mode.
 
 
 
 
 
 
1561	 */
1562	if (apic->init_apic_ldr)
1563		apic->init_apic_ldr();
 
 
 
 
1564
1565	/*
1566	 * Set Task Priority to 'accept all except vectors 0-31'.  An APIC
1567	 * vector in the 16-31 range could be delivered if TPR == 0, but we
1568	 * would think it's an exception and terrible things will happen.  We
1569	 * never change this later on.
1570	 */
1571	value = apic_read(APIC_TASKPRI);
1572	value &= ~APIC_TPRI_MASK;
1573	value |= 0x10;
1574	apic_write(APIC_TASKPRI, value);
1575
1576	/* Clear eventually stale ISR/IRR bits */
1577	apic_pending_intr_clear();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1578
1579	/*
1580	 * Now that we are all set up, enable the APIC
1581	 */
1582	value = apic_read(APIC_SPIV);
1583	value &= ~APIC_VECTOR_MASK;
1584	/*
1585	 * Enable APIC
1586	 */
1587	value |= APIC_SPIV_APIC_ENABLED;
1588
1589#ifdef CONFIG_X86_32
1590	/*
1591	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1592	 * certain networking cards. If high frequency interrupts are
1593	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1594	 * entry is masked/unmasked at a high rate as well then sooner or
1595	 * later IOAPIC line gets 'stuck', no more interrupts are received
1596	 * from the device. If focus CPU is disabled then the hang goes
1597	 * away, oh well :-(
1598	 *
1599	 * [ This bug can be reproduced easily with a level-triggered
1600	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1601	 *   BX chipset. ]
1602	 */
1603	/*
1604	 * Actually disabling the focus CPU check just makes the hang less
1605	 * frequent as it makes the interrupt distribution model be more
1606	 * like LRU than MRU (the short-term load is more even across CPUs).
1607	 */
1608
1609	/*
1610	 * - enable focus processor (bit==0)
1611	 * - 64bit mode always use processor focus
1612	 *   so no need to set it
1613	 */
1614	value &= ~APIC_SPIV_FOCUS_DISABLED;
1615#endif
1616
1617	/*
1618	 * Set spurious IRQ vector
1619	 */
1620	value |= SPURIOUS_APIC_VECTOR;
1621	apic_write(APIC_SPIV, value);
1622
1623	perf_events_lapic_init();
1624
1625	/*
1626	 * Set up LVT0, LVT1:
1627	 *
1628	 * set up through-local-APIC on the boot CPU's LINT0. This is not
1629	 * strictly necessary in pure symmetric-IO mode, but sometimes
1630	 * we delegate interrupts to the 8259A.
1631	 */
1632	/*
1633	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1634	 */
1635	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1636	if (!cpu && (pic_mode || !value || ioapic_is_disabled)) {
1637		value = APIC_DM_EXTINT;
1638		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1639	} else {
1640		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1641		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1642	}
1643	apic_write(APIC_LVT0, value);
1644
1645	/*
1646	 * Only the BSP sees the LINT1 NMI signal by default. This can be
1647	 * modified by apic_extnmi= boot option.
1648	 */
1649	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1650	    apic_extnmi == APIC_EXTNMI_ALL)
1651		value = APIC_DM_NMI;
1652	else
1653		value = APIC_DM_NMI | APIC_LVT_MASKED;
1654
1655	/* Is 82489DX ? */
1656	if (!lapic_is_integrated())
1657		value |= APIC_LVT_LEVEL_TRIGGER;
1658	apic_write(APIC_LVT1, value);
1659
1660#ifdef CONFIG_X86_MCE_INTEL
1661	/* Recheck CMCI information after local APIC is up on CPU #0 */
1662	if (!cpu)
1663		cmci_recheck();
1664#endif
1665}
1666
1667static void end_local_APIC_setup(void)
1668{
1669	lapic_setup_esr();
1670
1671#ifdef CONFIG_X86_32
1672	{
1673		unsigned int value;
1674		/* Disable the local apic timer */
1675		value = apic_read(APIC_LVTT);
1676		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1677		apic_write(APIC_LVTT, value);
1678	}
1679#endif
1680
1681	apic_pm_activate();
1682}
1683
1684/*
1685 * APIC setup function for application processors. Called from smpboot.c
1686 */
1687void apic_ap_setup(void)
1688{
1689	setup_local_APIC();
1690	end_local_APIC_setup();
1691}
1692
1693static __init void cpu_set_boot_apic(void);
1694
1695static __init void apic_read_boot_cpu_id(bool x2apic)
1696{
1697	/*
1698	 * This can be invoked from check_x2apic() before the APIC has been
1699	 * selected. But that code knows for sure that the BIOS enabled
1700	 * X2APIC.
1701	 */
1702	if (x2apic) {
1703		boot_cpu_physical_apicid = native_apic_msr_read(APIC_ID);
1704		boot_cpu_apic_version = GET_APIC_VERSION(native_apic_msr_read(APIC_LVR));
1705	} else {
1706		boot_cpu_physical_apicid = read_apic_id();
1707		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
1708	}
1709	cpu_set_boot_apic();
1710}
1711
1712#ifdef CONFIG_X86_X2APIC
1713int x2apic_mode;
1714EXPORT_SYMBOL_GPL(x2apic_mode);
1715
1716enum {
1717	X2APIC_OFF,
1718	X2APIC_DISABLED,
1719	/* All states below here have X2APIC enabled */
1720	X2APIC_ON,
1721	X2APIC_ON_LOCKED
1722};
1723static int x2apic_state;
1724
1725static bool x2apic_hw_locked(void)
1726{
1727	u64 ia32_cap;
1728	u64 msr;
1729
1730	ia32_cap = x86_read_arch_cap_msr();
1731	if (ia32_cap & ARCH_CAP_XAPIC_DISABLE) {
1732		rdmsrl(MSR_IA32_XAPIC_DISABLE_STATUS, msr);
1733		return (msr & LEGACY_XAPIC_DISABLED);
1734	}
1735	return false;
1736}
1737
1738static void __x2apic_disable(void)
1739{
1740	u64 msr;
1741
1742	if (!boot_cpu_has(X86_FEATURE_APIC))
1743		return;
1744
1745	rdmsrl(MSR_IA32_APICBASE, msr);
1746	if (!(msr & X2APIC_ENABLE))
1747		return;
1748	/* Disable xapic and x2apic first and then reenable xapic mode */
1749	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1750	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1751	printk_once(KERN_INFO "x2apic disabled\n");
1752}
1753
1754static void __x2apic_enable(void)
1755{
1756	u64 msr;
1757
1758	rdmsrl(MSR_IA32_APICBASE, msr);
1759	if (msr & X2APIC_ENABLE)
1760		return;
1761	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1762	printk_once(KERN_INFO "x2apic enabled\n");
1763}
1764
1765static int __init setup_nox2apic(char *str)
1766{
1767	if (x2apic_enabled()) {
1768		u32 apicid = native_apic_msr_read(APIC_ID);
1769
1770		if (apicid >= 255) {
1771			pr_warn("Apicid: %08x, cannot enforce nox2apic\n",
1772				apicid);
1773			return 0;
1774		}
1775		if (x2apic_hw_locked()) {
1776			pr_warn("APIC locked in x2apic mode, can't disable\n");
1777			return 0;
1778		}
1779		pr_warn("x2apic already enabled.\n");
1780		__x2apic_disable();
1781	}
1782	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1783	x2apic_state = X2APIC_DISABLED;
1784	x2apic_mode = 0;
1785	return 0;
1786}
1787early_param("nox2apic", setup_nox2apic);
1788
1789/* Called from cpu_init() to enable x2apic on (secondary) cpus */
1790void x2apic_setup(void)
1791{
1792	/*
1793	 * Try to make the AP's APIC state match that of the BSP,  but if the
1794	 * BSP is unlocked and the AP is locked then there is a state mismatch.
1795	 * Warn about the mismatch in case a GP fault occurs due to a locked AP
1796	 * trying to be turned off.
1797	 */
1798	if (x2apic_state != X2APIC_ON_LOCKED && x2apic_hw_locked())
1799		pr_warn("x2apic lock mismatch between BSP and AP.\n");
1800	/*
1801	 * If x2apic is not in ON or LOCKED state, disable it if already enabled
1802	 * from BIOS.
1803	 */
1804	if (x2apic_state < X2APIC_ON) {
1805		__x2apic_disable();
1806		return;
1807	}
1808	__x2apic_enable();
1809}
1810
1811static __init void apic_set_fixmap(void);
1812
1813static __init void x2apic_disable(void)
1814{
1815	u32 x2apic_id, state = x2apic_state;
1816
1817	x2apic_mode = 0;
1818	x2apic_state = X2APIC_DISABLED;
1819
1820	if (state != X2APIC_ON)
1821		return;
1822
1823	x2apic_id = read_apic_id();
1824	if (x2apic_id >= 255)
1825		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1826
1827	if (x2apic_hw_locked()) {
1828		pr_warn("Cannot disable locked x2apic, id: %08x\n", x2apic_id);
1829		return;
1830	}
1831
1832	__x2apic_disable();
1833	apic_set_fixmap();
1834}
1835
1836static __init void x2apic_enable(void)
1837{
1838	if (x2apic_state != X2APIC_OFF)
1839		return;
1840
1841	x2apic_mode = 1;
1842	x2apic_state = X2APIC_ON;
1843	__x2apic_enable();
1844}
1845
1846static __init void try_to_enable_x2apic(int remap_mode)
1847{
1848	if (x2apic_state == X2APIC_DISABLED)
1849		return;
1850
1851	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1852		u32 apic_limit = 255;
1853
1854		/*
1855		 * Using X2APIC without IR is not architecturally supported
1856		 * on bare metal but may be supported in guests.
1857		 */
1858		if (!x86_init.hyper.x2apic_available()) {
 
1859			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1860			x2apic_disable();
1861			return;
1862		}
1863
1864		/*
1865		 * If the hypervisor supports extended destination ID in
1866		 * MSI, that increases the maximum APIC ID that can be
1867		 * used for non-remapped IRQ domains.
1868		 */
1869		if (x86_init.hyper.msi_ext_dest_id()) {
1870			virt_ext_dest_id = 1;
1871			apic_limit = 32767;
1872		}
1873
1874		/*
1875		 * Without IR, all CPUs can be addressed by IOAPIC/MSI only
1876		 * in physical mode, and CPUs with an APIC ID that cannot
1877		 * be addressed must not be brought online.
1878		 */
1879		x2apic_set_max_apicid(apic_limit);
1880		x2apic_phys = 1;
1881	}
1882	x2apic_enable();
1883}
1884
1885void __init check_x2apic(void)
1886{
1887	if (x2apic_enabled()) {
1888		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1889		x2apic_mode = 1;
1890		if (x2apic_hw_locked())
1891			x2apic_state = X2APIC_ON_LOCKED;
1892		else
1893			x2apic_state = X2APIC_ON;
1894		apic_read_boot_cpu_id(true);
1895	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1896		x2apic_state = X2APIC_DISABLED;
1897	}
1898}
1899#else /* CONFIG_X86_X2APIC */
1900void __init check_x2apic(void)
1901{
1902	if (!apic_is_x2apic_enabled())
1903		return;
1904	/*
1905	 * Checkme: Can we simply turn off x2APIC here instead of disabling the APIC?
1906	 */
1907	pr_err("Kernel does not support x2APIC, please recompile with CONFIG_X86_X2APIC.\n");
1908	pr_err("Disabling APIC, expect reduced performance and functionality.\n");
1909
1910	apic_is_disabled = true;
1911	setup_clear_cpu_cap(X86_FEATURE_APIC);
1912}
 
1913
1914static inline void try_to_enable_x2apic(int remap_mode) { }
1915static inline void __x2apic_enable(void) { }
1916#endif /* !CONFIG_X86_X2APIC */
1917
 
 
 
 
 
 
 
 
 
 
 
1918void __init enable_IR_x2apic(void)
1919{
1920	unsigned long flags;
1921	int ret, ir_stat;
1922
1923	if (ioapic_is_disabled) {
1924		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1925		return;
1926	}
1927
1928	ir_stat = irq_remapping_prepare();
1929	if (ir_stat < 0 && !x2apic_supported())
1930		return;
1931
1932	ret = save_ioapic_entries();
1933	if (ret) {
1934		pr_info("Saving IO-APIC state failed: %d\n", ret);
1935		return;
1936	}
1937
1938	local_irq_save(flags);
1939	legacy_pic->mask_all();
1940	mask_ioapic_entries();
1941
1942	/* If irq_remapping_prepare() succeeded, try to enable it */
1943	if (ir_stat >= 0)
1944		ir_stat = irq_remapping_enable();
1945	/* ir_stat contains the remap mode or an error code */
1946	try_to_enable_x2apic(ir_stat);
1947
1948	if (ir_stat < 0)
1949		restore_ioapic_entries();
1950	legacy_pic->restore_mask();
1951	local_irq_restore(flags);
1952}
1953
1954#ifdef CONFIG_X86_64
1955/*
1956 * Detect and enable local APICs on non-SMP boards.
1957 * Original code written by Keir Fraser.
1958 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1959 * not correctly set up (usually the APIC timer won't work etc.)
1960 */
1961static bool __init detect_init_APIC(void)
1962{
1963	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1964		pr_info("No local APIC present\n");
1965		return false;
1966	}
1967
1968	register_lapic_address(APIC_DEFAULT_PHYS_BASE);
1969	return true;
1970}
1971#else
1972
1973static bool __init apic_verify(unsigned long addr)
1974{
1975	u32 features, h, l;
1976
1977	/*
1978	 * The APIC feature bit should now be enabled
1979	 * in `cpuid'
1980	 */
1981	features = cpuid_edx(1);
1982	if (!(features & (1 << X86_FEATURE_APIC))) {
1983		pr_warn("Could not enable APIC!\n");
1984		return false;
1985	}
1986	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
 
1987
1988	/* The BIOS may have set up the APIC at some other address */
1989	if (boot_cpu_data.x86 >= 6) {
1990		rdmsr(MSR_IA32_APICBASE, l, h);
1991		if (l & MSR_IA32_APICBASE_ENABLE)
1992			addr = l & MSR_IA32_APICBASE_BASE;
1993	}
1994
1995	register_lapic_address(addr);
1996	pr_info("Found and enabled local APIC!\n");
1997	return true;
1998}
1999
2000bool __init apic_force_enable(unsigned long addr)
2001{
2002	u32 h, l;
2003
2004	if (apic_is_disabled)
2005		return false;
2006
2007	/*
2008	 * Some BIOSes disable the local APIC in the APIC_BASE
2009	 * MSR. This can only be done in software for Intel P6 or later
2010	 * and AMD K7 (Model > 1) or later.
2011	 */
2012	if (boot_cpu_data.x86 >= 6) {
2013		rdmsr(MSR_IA32_APICBASE, l, h);
2014		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
2015			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
2016			l &= ~MSR_IA32_APICBASE_BASE;
2017			l |= MSR_IA32_APICBASE_ENABLE | addr;
2018			wrmsr(MSR_IA32_APICBASE, l, h);
2019			enabled_via_apicbase = 1;
2020		}
2021	}
2022	return apic_verify(addr);
2023}
2024
2025/*
2026 * Detect and initialize APIC
2027 */
2028static bool __init detect_init_APIC(void)
2029{
2030	/* Disabled by kernel option? */
2031	if (apic_is_disabled)
2032		return false;
2033
2034	switch (boot_cpu_data.x86_vendor) {
2035	case X86_VENDOR_AMD:
2036		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
2037		    (boot_cpu_data.x86 >= 15))
2038			break;
2039		goto no_apic;
2040	case X86_VENDOR_HYGON:
2041		break;
2042	case X86_VENDOR_INTEL:
2043		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
2044		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
2045			break;
2046		goto no_apic;
2047	default:
2048		goto no_apic;
2049	}
2050
2051	if (!boot_cpu_has(X86_FEATURE_APIC)) {
2052		/*
2053		 * Over-ride BIOS and try to enable the local APIC only if
2054		 * "lapic" specified.
2055		 */
2056		if (!force_enable_local_apic) {
2057			pr_info("Local APIC disabled by BIOS -- "
2058				"you can enable it with \"lapic\"\n");
2059			return false;
2060		}
2061		if (!apic_force_enable(APIC_DEFAULT_PHYS_BASE))
2062			return false;
2063	} else {
2064		if (!apic_verify(APIC_DEFAULT_PHYS_BASE))
2065			return false;
2066	}
2067
2068	apic_pm_activate();
2069
2070	return true;
2071
2072no_apic:
2073	pr_info("No local APIC present or hardware disabled\n");
2074	return false;
2075}
2076#endif
2077
2078/**
2079 * init_apic_mappings - initialize APIC mappings
2080 */
2081void __init init_apic_mappings(void)
2082{
2083	if (apic_validate_deadline_timer())
2084		pr_info("TSC deadline timer available\n");
2085
2086	if (x2apic_mode)
 
2087		return;
 
2088
2089	if (!smp_found_config) {
2090		if (!detect_init_APIC()) {
2091			pr_info("APIC: disable apic facility\n");
2092			apic_disable();
2093		}
2094		num_processors = 1;
 
 
 
 
 
 
 
 
2095	}
2096}
2097
2098static __init void apic_set_fixmap(void)
2099{
2100	set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);
2101	apic_mmio_base = APIC_BASE;
2102	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2103		    apic_mmio_base, mp_lapic_addr);
2104	apic_read_boot_cpu_id(false);
 
 
 
 
 
 
 
 
 
2105}
2106
2107void __init register_lapic_address(unsigned long address)
2108{
2109	/* This should only happen once */
2110	WARN_ON_ONCE(mp_lapic_addr);
2111	mp_lapic_addr = address;
2112
2113	if (!x2apic_mode)
2114		apic_set_fixmap();
 
 
 
 
 
 
 
2115}
2116
2117/*
2118 * Local APIC interrupts
2119 */
2120
2121/*
2122 * Common handling code for spurious_interrupt and spurious_vector entry
2123 * points below. No point in allowing the compiler to inline it twice.
2124 */
2125static noinline void handle_spurious_interrupt(u8 vector)
2126{
2127	u32 v;
2128
2129	trace_spurious_apic_entry(vector);
2130
2131	inc_irq_stat(irq_spurious_count);
2132
2133	/*
2134	 * If this is a spurious interrupt then do not acknowledge
2135	 */
2136	if (vector == SPURIOUS_APIC_VECTOR) {
2137		/* See SDM vol 3 */
2138		pr_info("Spurious APIC interrupt (vector 0xFF) on CPU#%d, should never happen.\n",
2139			smp_processor_id());
2140		goto out;
2141	}
2142
2143	/*
2144	 * If it is a vectored one, verify it's set in the ISR. If set,
2145	 * acknowledge it.
 
2146	 */
2147	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2148	if (v & (1 << (vector & 0x1f))) {
2149		pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Acked\n",
2150			vector, smp_processor_id());
2151		apic_eoi();
2152	} else {
2153		pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Not pending!\n",
2154			vector, smp_processor_id());
2155	}
2156out:
2157	trace_spurious_apic_exit(vector);
2158}
2159
2160/**
2161 * spurious_interrupt - Catch all for interrupts raised on unused vectors
2162 * @regs:	Pointer to pt_regs on stack
2163 * @vector:	The vector number
2164 *
2165 * This is invoked from ASM entry code to catch all interrupts which
2166 * trigger on an entry which is routed to the common_spurious idtentry
2167 * point.
2168 */
2169DEFINE_IDTENTRY_IRQ(spurious_interrupt)
2170{
2171	handle_spurious_interrupt(vector);
 
 
2172}
2173
2174DEFINE_IDTENTRY_SYSVEC(sysvec_spurious_apic_interrupt)
2175{
2176	handle_spurious_interrupt(SPURIOUS_APIC_VECTOR);
 
 
 
 
 
 
2177}
2178
2179/*
2180 * This interrupt should never happen with our APIC/SMP architecture
2181 */
2182DEFINE_IDTENTRY_SYSVEC(sysvec_error_interrupt)
2183{
 
 
2184	static const char * const error_interrupt_reason[] = {
2185		"Send CS error",		/* APIC Error Bit 0 */
2186		"Receive CS error",		/* APIC Error Bit 1 */
2187		"Send accept error",		/* APIC Error Bit 2 */
2188		"Receive accept error",		/* APIC Error Bit 3 */
2189		"Redirectable IPI",		/* APIC Error Bit 4 */
2190		"Send illegal vector",		/* APIC Error Bit 5 */
2191		"Received illegal vector",	/* APIC Error Bit 6 */
2192		"Illegal register address",	/* APIC Error Bit 7 */
2193	};
2194	u32 v, i = 0;
2195
2196	trace_error_apic_entry(ERROR_APIC_VECTOR);
2197
2198	/* First tickle the hardware, only then report what went on. -- REW */
2199	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
2200		apic_write(APIC_ESR, 0);
2201	v = apic_read(APIC_ESR);
2202	apic_eoi();
2203	atomic_inc(&irq_err_count);
2204
2205	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2206		    smp_processor_id(), v);
2207
2208	v &= 0xff;
2209	while (v) {
2210		if (v & 0x1)
2211			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2212		i++;
2213		v >>= 1;
2214	}
2215
2216	apic_printk(APIC_DEBUG, KERN_CONT "\n");
2217
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2218	trace_error_apic_exit(ERROR_APIC_VECTOR);
 
2219}
2220
2221/**
2222 * connect_bsp_APIC - attach the APIC to the interrupt system
2223 */
2224static void __init connect_bsp_APIC(void)
2225{
2226#ifdef CONFIG_X86_32
2227	if (pic_mode) {
2228		/*
2229		 * Do not trust the local APIC being empty at bootup.
2230		 */
2231		clear_local_APIC();
2232		/*
2233		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
2234		 * local APIC to INT and NMI lines.
2235		 */
2236		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2237				"enabling APIC mode.\n");
2238		imcr_pic_to_apic();
2239	}
2240#endif
2241}
2242
2243/**
2244 * disconnect_bsp_APIC - detach the APIC from the interrupt system
2245 * @virt_wire_setup:	indicates, whether virtual wire mode is selected
2246 *
2247 * Virtual wire mode is necessary to deliver legacy interrupts even when the
2248 * APIC is disabled.
2249 */
2250void disconnect_bsp_APIC(int virt_wire_setup)
2251{
2252	unsigned int value;
2253
2254#ifdef CONFIG_X86_32
2255	if (pic_mode) {
2256		/*
2257		 * Put the board back into PIC mode (has an effect only on
2258		 * certain older boards).  Note that APIC interrupts, including
2259		 * IPIs, won't work beyond this point!  The only exception are
2260		 * INIT IPIs.
2261		 */
2262		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2263				"entering PIC mode.\n");
2264		imcr_apic_to_pic();
2265		return;
2266	}
2267#endif
2268
2269	/* Go back to Virtual Wire compatibility mode */
2270
2271	/* For the spurious interrupt use vector F, and enable it */
2272	value = apic_read(APIC_SPIV);
2273	value &= ~APIC_VECTOR_MASK;
2274	value |= APIC_SPIV_APIC_ENABLED;
2275	value |= 0xf;
2276	apic_write(APIC_SPIV, value);
2277
2278	if (!virt_wire_setup) {
2279		/*
2280		 * For LVT0 make it edge triggered, active high,
2281		 * external and enabled
2282		 */
2283		value = apic_read(APIC_LVT0);
2284		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2285			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2286			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2287		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2288		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2289		apic_write(APIC_LVT0, value);
2290	} else {
2291		/* Disable LVT0 */
2292		apic_write(APIC_LVT0, APIC_LVT_MASKED);
2293	}
2294
2295	/*
2296	 * For LVT1 make it edge triggered, active high,
2297	 * nmi and enabled
2298	 */
2299	value = apic_read(APIC_LVT1);
2300	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2301			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2302			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2303	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2304	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2305	apic_write(APIC_LVT1, value);
2306}
2307
2308/*
2309 * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2310 * contiguously, it equals to current allocated max logical CPU ID plus 1.
2311 * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2312 * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2313 *
2314 * NOTE: Reserve 0 for BSP.
2315 */
2316static int nr_logical_cpuids = 1;
2317
2318/*
2319 * Used to store mapping between logical CPU IDs and APIC IDs.
2320 */
2321u32 cpuid_to_apicid[] = { [0 ... NR_CPUS - 1] = BAD_APICID, };
2322
2323bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
2324{
2325	return phys_id == (u64)cpuid_to_apicid[cpu];
2326}
2327
2328#ifdef CONFIG_SMP
2329static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
2330{
2331	/* Isolate the SMT bit(s) in the APICID and check for 0 */
2332	u32 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
2333
2334	if (smp_num_siblings == 1 || !(apicid & mask))
2335		cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
2336}
2337
2338/*
2339 * Due to the utter mess of CPUID evaluation smp_num_siblings is not valid
2340 * during early boot. Initialize the primary thread mask before SMP
2341 * bringup.
2342 */
2343static int __init smp_init_primary_thread_mask(void)
2344{
2345	unsigned int cpu;
2346
2347	/*
2348	 * XEN/PV provides either none or useless topology information.
2349	 * Pretend that all vCPUs are primary threads.
2350	 */
2351	if (xen_pv_domain()) {
2352		cpumask_copy(&__cpu_primary_thread_mask, cpu_possible_mask);
2353		return 0;
2354	}
2355
2356	for (cpu = 0; cpu < nr_logical_cpuids; cpu++)
2357		cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
2358	return 0;
2359}
2360early_initcall(smp_init_primary_thread_mask);
2361#else
2362static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { }
2363#endif
2364
2365/*
2366 * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2367 * and cpuid_to_apicid[] synchronized.
2368 */
2369static int allocate_logical_cpuid(int apicid)
2370{
2371	int i;
2372
2373	/*
2374	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2375	 * check if the kernel has allocated a cpuid for it.
2376	 */
2377	for (i = 0; i < nr_logical_cpuids; i++) {
2378		if (cpuid_to_apicid[i] == apicid)
2379			return i;
2380	}
2381
2382	/* Allocate a new cpuid. */
2383	if (nr_logical_cpuids >= nr_cpu_ids) {
2384		WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2385			     "Processor %d/0x%x and the rest are ignored.\n",
2386			     nr_cpu_ids, nr_logical_cpuids, apicid);
2387		return -EINVAL;
2388	}
2389
2390	cpuid_to_apicid[nr_logical_cpuids] = apicid;
2391	return nr_logical_cpuids++;
2392}
2393
2394static void cpu_update_apic(int cpu, u32 apicid)
2395{
2396#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2397	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2398#endif
2399	set_cpu_possible(cpu, true);
2400	physid_set(apicid, phys_cpu_present_map);
2401	set_cpu_present(cpu, true);
2402	num_processors++;
2403
2404	if (system_state != SYSTEM_BOOTING)
2405		cpu_mark_primary_thread(cpu, apicid);
2406}
2407
2408static __init void cpu_set_boot_apic(void)
2409{
2410	cpuid_to_apicid[0] = boot_cpu_physical_apicid;
2411	cpu_update_apic(0, boot_cpu_physical_apicid);
2412	x86_32_probe_bigsmp_early();
2413}
2414
2415int generic_processor_info(int apicid)
2416{
2417	int cpu, max = nr_cpu_ids;
 
 
2418
2419	/* The boot CPU must be set before MADT/MPTABLE parsing happens */
2420	if (cpuid_to_apicid[0] == BAD_APICID)
2421		panic("Boot CPU APIC not registered yet\n");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2422
2423	if (apicid == boot_cpu_physical_apicid)
2424		return 0;
 
2425
2426	if (disabled_cpu_apicid == apicid) {
2427		int thiscpu = num_processors + disabled_cpus;
 
2428
2429		pr_warn("APIC: Disabling requested cpu. Processor %d/0x%x ignored.\n",
2430			thiscpu, apicid);
 
 
 
 
 
 
 
 
 
 
2431
2432		disabled_cpus++;
2433		return -ENODEV;
2434	}
2435
2436	if (num_processors >= nr_cpu_ids) {
2437		int thiscpu = max + disabled_cpus;
2438
2439		pr_warn("APIC: NR_CPUS/possible_cpus limit of %i reached. "
2440			"Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
 
 
 
2441
2442		disabled_cpus++;
2443		return -EINVAL;
2444	}
2445
2446	cpu = allocate_logical_cpuid(apicid);
2447	if (cpu < 0) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2448		disabled_cpus++;
2449		return -EINVAL;
2450	}
2451
2452	cpu_update_apic(cpu, apicid);
2453	return cpu;
2454}
2455
 
 
 
 
 
 
 
 
 
2456
2457void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
2458			   bool dmar)
2459{
2460	memset(msg, 0, sizeof(*msg));
2461
2462	msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
2463	msg->arch_addr_lo.dest_mode_logical = apic->dest_mode_logical;
2464	msg->arch_addr_lo.destid_0_7 = cfg->dest_apicid & 0xFF;
2465
2466	msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_FIXED;
2467	msg->arch_data.vector = cfg->vector;
2468
2469	msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
2470	/*
2471	 * Only the IOMMU itself can use the trick of putting destination
2472	 * APIC ID into the high bits of the address. Anything else would
2473	 * just be writing to memory if it tried that, and needs IR to
2474	 * address APICs which can't be addressed in the normal 32-bit
2475	 * address range at 0xFFExxxxx. That is typically just 8 bits, but
2476	 * some hypervisors allow the extended destination ID field in bits
2477	 * 5-11 to be used, giving support for 15 bits of APIC IDs in total.
2478	 */
2479	if (dmar)
2480		msg->arch_addr_hi.destid_8_31 = cfg->dest_apicid >> 8;
2481	else if (virt_ext_dest_id && cfg->dest_apicid < 0x8000)
2482		msg->arch_addr_lo.virt_destid_8_14 = cfg->dest_apicid >> 8;
2483	else
2484		WARN_ON_ONCE(cfg->dest_apicid > 0xFF);
2485}
2486
2487u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid)
 
 
2488{
2489	u32 dest = msg->arch_addr_lo.destid_0_7;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2490
2491	if (extid)
2492		dest |= msg->arch_addr_hi.destid_8_31 << 8;
2493	return dest;
 
 
 
2494}
2495EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid);
2496
2497static void __init apic_bsp_up_setup(void)
2498{
2499#ifdef CONFIG_X86_64
2500	apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
 
 
 
 
 
 
 
 
 
2501#endif
2502	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2503}
2504
2505/**
2506 * apic_bsp_setup - Setup function for local apic and io-apic
2507 * @upmode:		Force UP mode (for APIC_init_uniprocessor)
 
 
 
2508 */
2509static void __init apic_bsp_setup(bool upmode)
2510{
 
 
2511	connect_bsp_APIC();
2512	if (upmode)
2513		apic_bsp_up_setup();
2514	setup_local_APIC();
2515
 
 
 
 
 
2516	enable_IO_APIC();
2517	end_local_APIC_setup();
2518	irq_remap_enable_fault_handling();
2519	setup_IO_APIC();
2520	lapic_update_legacy_vectors();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2521}
2522
2523#ifdef CONFIG_UP_LATE_INIT
2524void __init up_late_init(void)
2525{
2526	if (apic_intr_mode == APIC_PIC)
2527		return;
2528
2529	/* Setup local timer */
2530	x86_init.timers.setup_percpu_clockev();
2531}
2532#endif
2533
2534/*
2535 * Power management
2536 */
2537#ifdef CONFIG_PM
2538
2539static struct {
2540	/*
2541	 * 'active' is true if the local APIC was enabled by us and
2542	 * not the BIOS; this signifies that we are also responsible
2543	 * for disabling it before entering apm/acpi suspend
2544	 */
2545	int active;
2546	/* r/w apic fields */
2547	u32 apic_id;
2548	unsigned int apic_taskpri;
2549	unsigned int apic_ldr;
2550	unsigned int apic_dfr;
2551	unsigned int apic_spiv;
2552	unsigned int apic_lvtt;
2553	unsigned int apic_lvtpc;
2554	unsigned int apic_lvt0;
2555	unsigned int apic_lvt1;
2556	unsigned int apic_lvterr;
2557	unsigned int apic_tmict;
2558	unsigned int apic_tdcr;
2559	unsigned int apic_thmr;
2560	unsigned int apic_cmci;
2561} apic_pm_state;
2562
2563static int lapic_suspend(void)
2564{
2565	unsigned long flags;
2566	int maxlvt;
2567
2568	if (!apic_pm_state.active)
2569		return 0;
2570
2571	maxlvt = lapic_get_maxlvt();
2572
2573	apic_pm_state.apic_id = apic_read(APIC_ID);
2574	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2575	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2576	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2577	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2578	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2579	if (maxlvt >= 4)
2580		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2581	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2582	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2583	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2584	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2585	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2586#ifdef CONFIG_X86_THERMAL_VECTOR
2587	if (maxlvt >= 5)
2588		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2589#endif
2590#ifdef CONFIG_X86_MCE_INTEL
2591	if (maxlvt >= 6)
2592		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2593#endif
2594
2595	local_irq_save(flags);
2596
2597	/*
2598	 * Mask IOAPIC before disabling the local APIC to prevent stale IRR
2599	 * entries on some implementations.
2600	 */
2601	mask_ioapic_entries();
2602
2603	disable_local_APIC();
2604
2605	irq_remapping_disable();
2606
2607	local_irq_restore(flags);
2608	return 0;
2609}
2610
2611static void lapic_resume(void)
2612{
2613	unsigned int l, h;
2614	unsigned long flags;
2615	int maxlvt;
2616
2617	if (!apic_pm_state.active)
2618		return;
2619
2620	local_irq_save(flags);
2621
2622	/*
2623	 * IO-APIC and PIC have their own resume routines.
2624	 * We just mask them here to make sure the interrupt
2625	 * subsystem is completely quiet while we enable x2apic
2626	 * and interrupt-remapping.
2627	 */
2628	mask_ioapic_entries();
2629	legacy_pic->mask_all();
2630
2631	if (x2apic_mode) {
2632		__x2apic_enable();
2633	} else {
2634		/*
2635		 * Make sure the APICBASE points to the right address
2636		 *
2637		 * FIXME! This will be wrong if we ever support suspend on
2638		 * SMP! We'll need to do this as part of the CPU restore!
2639		 */
2640		if (boot_cpu_data.x86 >= 6) {
2641			rdmsr(MSR_IA32_APICBASE, l, h);
2642			l &= ~MSR_IA32_APICBASE_BASE;
2643			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2644			wrmsr(MSR_IA32_APICBASE, l, h);
2645		}
2646	}
2647
2648	maxlvt = lapic_get_maxlvt();
2649	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2650	apic_write(APIC_ID, apic_pm_state.apic_id);
2651	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2652	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2653	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2654	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2655	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2656	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2657#ifdef CONFIG_X86_THERMAL_VECTOR
2658	if (maxlvt >= 5)
2659		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2660#endif
2661#ifdef CONFIG_X86_MCE_INTEL
2662	if (maxlvt >= 6)
2663		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2664#endif
2665	if (maxlvt >= 4)
2666		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2667	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2668	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2669	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2670	apic_write(APIC_ESR, 0);
2671	apic_read(APIC_ESR);
2672	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2673	apic_write(APIC_ESR, 0);
2674	apic_read(APIC_ESR);
2675
2676	irq_remapping_reenable(x2apic_mode);
2677
2678	local_irq_restore(flags);
2679}
2680
2681/*
2682 * This device has no shutdown method - fully functioning local APICs
2683 * are needed on every CPU up until machine_halt/restart/poweroff.
2684 */
2685
2686static struct syscore_ops lapic_syscore_ops = {
2687	.resume		= lapic_resume,
2688	.suspend	= lapic_suspend,
2689};
2690
2691static void apic_pm_activate(void)
2692{
2693	apic_pm_state.active = 1;
2694}
2695
2696static int __init init_lapic_sysfs(void)
2697{
2698	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2699	if (boot_cpu_has(X86_FEATURE_APIC))
2700		register_syscore_ops(&lapic_syscore_ops);
2701
2702	return 0;
2703}
2704
2705/* local apic needs to resume before other devices access its registers. */
2706core_initcall(init_lapic_sysfs);
2707
2708#else	/* CONFIG_PM */
2709
2710static void apic_pm_activate(void) { }
2711
2712#endif	/* CONFIG_PM */
2713
2714#ifdef CONFIG_X86_64
2715
2716static int multi_checked;
2717static int multi;
2718
2719static int set_multi(const struct dmi_system_id *d)
2720{
2721	if (multi)
2722		return 0;
2723	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2724	multi = 1;
2725	return 0;
2726}
2727
2728static const struct dmi_system_id multi_dmi_table[] = {
2729	{
2730		.callback = set_multi,
2731		.ident = "IBM System Summit2",
2732		.matches = {
2733			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2734			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2735		},
2736	},
2737	{}
2738};
2739
2740static void dmi_check_multi(void)
2741{
2742	if (multi_checked)
2743		return;
2744
2745	dmi_check_system(multi_dmi_table);
2746	multi_checked = 1;
2747}
2748
2749/*
2750 * apic_is_clustered_box() -- Check if we can expect good TSC
2751 *
2752 * Thus far, the major user of this is IBM's Summit2 series:
2753 * Clustered boxes may have unsynced TSC problems if they are
2754 * multi-chassis.
2755 * Use DMI to check them
2756 */
2757int apic_is_clustered_box(void)
2758{
2759	dmi_check_multi();
2760	return multi;
2761}
2762#endif
2763
2764/*
2765 * APIC command line parameters
2766 */
2767static int __init setup_disableapic(char *arg)
2768{
2769	apic_is_disabled = true;
2770	setup_clear_cpu_cap(X86_FEATURE_APIC);
2771	return 0;
2772}
2773early_param("disableapic", setup_disableapic);
2774
2775/* same as disableapic, for compatibility */
2776static int __init setup_nolapic(char *arg)
2777{
2778	return setup_disableapic(arg);
2779}
2780early_param("nolapic", setup_nolapic);
2781
2782static int __init parse_lapic_timer_c2_ok(char *arg)
2783{
2784	local_apic_timer_c2_ok = 1;
2785	return 0;
2786}
2787early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2788
2789static int __init parse_disable_apic_timer(char *arg)
2790{
2791	disable_apic_timer = 1;
2792	return 0;
2793}
2794early_param("noapictimer", parse_disable_apic_timer);
2795
2796static int __init parse_nolapic_timer(char *arg)
2797{
2798	disable_apic_timer = 1;
2799	return 0;
2800}
2801early_param("nolapic_timer", parse_nolapic_timer);
2802
2803static int __init apic_set_verbosity(char *arg)
2804{
2805	if (!arg)  {
2806		if (IS_ENABLED(CONFIG_X86_32))
2807			return -EINVAL;
2808
2809		ioapic_is_disabled = false;
2810		return 0;
 
 
2811	}
2812
2813	if (strcmp("debug", arg) == 0)
2814		apic_verbosity = APIC_DEBUG;
2815	else if (strcmp("verbose", arg) == 0)
2816		apic_verbosity = APIC_VERBOSE;
2817#ifdef CONFIG_X86_64
2818	else {
2819		pr_warn("APIC Verbosity level %s not recognised"
2820			" use apic=verbose or apic=debug\n", arg);
2821		return -EINVAL;
2822	}
2823#endif
2824
2825	return 0;
2826}
2827early_param("apic", apic_set_verbosity);
2828
2829static int __init lapic_insert_resource(void)
2830{
2831	if (!apic_mmio_base)
2832		return -1;
2833
2834	/* Put local APIC into the resource map. */
2835	lapic_resource.start = apic_mmio_base;
2836	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2837	insert_resource(&iomem_resource, &lapic_resource);
2838
2839	return 0;
2840}
2841
2842/*
2843 * need call insert after e820__reserve_resources()
2844 * that is using request_resource
2845 */
2846late_initcall(lapic_insert_resource);
2847
2848static int __init apic_set_disabled_cpu_apicid(char *arg)
2849{
2850	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2851		return -EINVAL;
2852
2853	return 0;
2854}
2855early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2856
2857static int __init apic_set_extnmi(char *arg)
2858{
2859	if (!arg)
2860		return -EINVAL;
2861
2862	if (!strncmp("all", arg, 3))
2863		apic_extnmi = APIC_EXTNMI_ALL;
2864	else if (!strncmp("none", arg, 4))
2865		apic_extnmi = APIC_EXTNMI_NONE;
2866	else if (!strncmp("bsp", arg, 3))
2867		apic_extnmi = APIC_EXTNMI_BSP;
2868	else {
2869		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2870		return -EINVAL;
2871	}
2872
2873	return 0;
2874}
2875early_param("apic_extnmi", apic_set_extnmi);
v4.10.11
 
   1/*
   2 *	Local APIC handling, local APIC timers
   3 *
   4 *	(c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
   5 *
   6 *	Fixes
   7 *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
   8 *					thanks to Eric Gilmore
   9 *					and Rolf G. Tews
  10 *					for testing these extensively.
  11 *	Maciej W. Rozycki	:	Various updates and fixes.
  12 *	Mikael Pettersson	:	Power Management for UP-APIC.
  13 *	Pavel Machek and
  14 *	Mikael Pettersson	:	PM converted to driver model.
  15 */
  16
  17#include <linux/perf_event.h>
  18#include <linux/kernel_stat.h>
  19#include <linux/mc146818rtc.h>
  20#include <linux/acpi_pmtmr.h>
  21#include <linux/clockchips.h>
  22#include <linux/interrupt.h>
  23#include <linux/bootmem.h>
  24#include <linux/ftrace.h>
  25#include <linux/ioport.h>
  26#include <linux/export.h>
  27#include <linux/syscore_ops.h>
  28#include <linux/delay.h>
  29#include <linux/timex.h>
  30#include <linux/i8253.h>
  31#include <linux/dmar.h>
  32#include <linux/init.h>
  33#include <linux/cpu.h>
  34#include <linux/dmi.h>
  35#include <linux/smp.h>
  36#include <linux/mm.h>
  37
 
 
  38#include <asm/trace/irq_vectors.h>
  39#include <asm/irq_remapping.h>
 
  40#include <asm/perf_event.h>
  41#include <asm/x86_init.h>
  42#include <asm/pgalloc.h>
  43#include <linux/atomic.h>
 
  44#include <asm/mpspec.h>
  45#include <asm/i8259.h>
  46#include <asm/proto.h>
 
  47#include <asm/apic.h>
 
  48#include <asm/io_apic.h>
  49#include <asm/desc.h>
  50#include <asm/hpet.h>
  51#include <asm/mtrr.h>
  52#include <asm/time.h>
  53#include <asm/smp.h>
  54#include <asm/mce.h>
  55#include <asm/tsc.h>
  56#include <asm/hypervisor.h>
 
 
 
 
 
 
  57
  58unsigned int num_processors;
  59
  60unsigned disabled_cpus;
  61
  62/* Processor that is doing the boot up */
  63unsigned int boot_cpu_physical_apicid = -1U;
  64EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
  65
  66u8 boot_cpu_apic_version;
  67
  68/*
  69 * The highest APIC ID seen during enumeration.
  70 */
  71static unsigned int max_physical_apicid;
  72
  73/*
  74 * Bitmask of physically existing CPUs:
  75 */
  76physid_mask_t phys_cpu_present_map;
  77
  78/*
  79 * Processor to be disabled specified by kernel parameter
  80 * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
  81 * avoid undefined behaviour caused by sending INIT from AP to BSP.
  82 */
  83static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID;
  84
  85/*
  86 * This variable controls which CPUs receive external NMIs.  By default,
  87 * external NMIs are delivered only to the BSP.
  88 */
  89static int apic_extnmi = APIC_EXTNMI_BSP;
 
 
 
 
 
 
 
 
 
 
 
 
 
  90
  91/*
  92 * Map cpu index to physical APIC ID
  93 */
  94DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
  95DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
  96DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
  97EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
  98EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
  99EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
 100
 101#ifdef CONFIG_X86_32
 102
 103/*
 104 * On x86_32, the mapping between cpu and logical apicid may vary
 105 * depending on apic in use.  The following early percpu variable is
 106 * used for the mapping.  This is where the behaviors of x86_64 and 32
 107 * actually diverge.  Let's keep it ugly for now.
 108 */
 109DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
 110
 111/* Local APIC was disabled by the BIOS and enabled by the kernel */
 112static int enabled_via_apicbase;
 113
 114/*
 115 * Handle interrupt mode configuration register (IMCR).
 116 * This register controls whether the interrupt signals
 117 * that reach the BSP come from the master PIC or from the
 118 * local APIC. Before entering Symmetric I/O Mode, either
 119 * the BIOS or the operating system must switch out of
 120 * PIC Mode by changing the IMCR.
 121 */
 122static inline void imcr_pic_to_apic(void)
 123{
 124	/* select IMCR register */
 125	outb(0x70, 0x22);
 126	/* NMI and 8259 INTR go through APIC */
 127	outb(0x01, 0x23);
 128}
 129
 130static inline void imcr_apic_to_pic(void)
 131{
 132	/* select IMCR register */
 133	outb(0x70, 0x22);
 134	/* NMI and 8259 INTR go directly to BSP */
 135	outb(0x00, 0x23);
 136}
 137#endif
 138
 139/*
 140 * Knob to control our willingness to enable the local APIC.
 141 *
 142 * +1=force-enable
 143 */
 144static int force_enable_local_apic __initdata;
 145
 146/*
 147 * APIC command line parameters
 148 */
 149static int __init parse_lapic(char *arg)
 150{
 151	if (IS_ENABLED(CONFIG_X86_32) && !arg)
 152		force_enable_local_apic = 1;
 153	else if (arg && !strncmp(arg, "notscdeadline", 13))
 154		setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
 155	return 0;
 156}
 157early_param("lapic", parse_lapic);
 158
 159#ifdef CONFIG_X86_64
 160static int apic_calibrate_pmtmr __initdata;
 161static __init int setup_apicpmtimer(char *s)
 162{
 163	apic_calibrate_pmtmr = 1;
 164	notsc_setup(NULL);
 165	return 0;
 166}
 167__setup("apicpmtimer", setup_apicpmtimer);
 168#endif
 169
 170unsigned long mp_lapic_addr;
 171int disable_apic;
 172/* Disable local APIC timer from the kernel commandline or via dmi quirk */
 173static int disable_apic_timer __initdata;
 174/* Local APIC timer works in C2 */
 175int local_apic_timer_c2_ok;
 176EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
 177
 178int first_system_vector = FIRST_SYSTEM_VECTOR;
 179
 180/*
 181 * Debug level, exported for io_apic.c
 182 */
 183unsigned int apic_verbosity;
 184
 185int pic_mode;
 186
 187/* Have we found an MP table */
 188int smp_found_config;
 189
 190static struct resource lapic_resource = {
 191	.name = "Local APIC",
 192	.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
 193};
 194
 195unsigned int lapic_timer_frequency = 0;
 196
 197static void apic_pm_activate(void);
 198
 199static unsigned long apic_phys;
 200
 201/*
 202 * Get the LAPIC version
 203 */
 204static inline int lapic_get_version(void)
 205{
 206	return GET_APIC_VERSION(apic_read(APIC_LVR));
 207}
 208
 209/*
 210 * Check, if the APIC is integrated or a separate chip
 211 */
 212static inline int lapic_is_integrated(void)
 213{
 214#ifdef CONFIG_X86_64
 215	return 1;
 216#else
 217	return APIC_INTEGRATED(lapic_get_version());
 218#endif
 219}
 220
 221/*
 222 * Check, whether this is a modern or a first generation APIC
 223 */
 224static int modern_apic(void)
 225{
 226	/* AMD systems use old APIC versions, so check the CPU */
 227	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
 228	    boot_cpu_data.x86 >= 0xf)
 229		return 1;
 
 
 
 
 
 230	return lapic_get_version() >= 0x14;
 231}
 232
 233/*
 234 * right after this call apic become NOOP driven
 235 * so apic->write/read doesn't do anything
 236 */
 237static void __init apic_disable(void)
 238{
 239	pr_info("APIC: switched to apic NOOP\n");
 240	apic = &apic_noop;
 241}
 242
 243void native_apic_wait_icr_idle(void)
 244{
 245	while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
 246		cpu_relax();
 247}
 248
 249u32 native_safe_apic_wait_icr_idle(void)
 250{
 251	u32 send_status;
 252	int timeout;
 253
 254	timeout = 0;
 255	do {
 256		send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
 257		if (!send_status)
 258			break;
 259		inc_irq_stat(icr_read_retry_count);
 260		udelay(100);
 261	} while (timeout++ < 1000);
 262
 263	return send_status;
 264}
 265
 266void native_apic_icr_write(u32 low, u32 id)
 267{
 268	unsigned long flags;
 269
 270	local_irq_save(flags);
 271	apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
 272	apic_write(APIC_ICR, low);
 273	local_irq_restore(flags);
 274}
 275
 276u64 native_apic_icr_read(void)
 277{
 278	u32 icr1, icr2;
 279
 280	icr2 = apic_read(APIC_ICR2);
 281	icr1 = apic_read(APIC_ICR);
 282
 283	return icr1 | ((u64)icr2 << 32);
 284}
 285
 286#ifdef CONFIG_X86_32
 287/**
 288 * get_physical_broadcast - Get number of physical broadcast IDs
 289 */
 290int get_physical_broadcast(void)
 291{
 292	return modern_apic() ? 0xff : 0xf;
 293}
 294#endif
 295
 296/**
 297 * lapic_get_maxlvt - get the maximum number of local vector table entries
 298 */
 299int lapic_get_maxlvt(void)
 300{
 301	unsigned int v;
 302
 303	v = apic_read(APIC_LVR);
 304	/*
 305	 * - we always have APIC integrated on 64bit mode
 306	 * - 82489DXs do not report # of LVT entries
 307	 */
 308	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
 309}
 310
 311/*
 312 * Local APIC timer
 313 */
 314
 315/* Clock divisor */
 316#define APIC_DIVISOR 16
 317#define TSC_DIVISOR  8
 318
 
 
 
 319/*
 320 * This function sets up the local APIC timer, with a timeout of
 321 * 'clocks' APIC bus clock. During calibration we actually call
 322 * this function twice on the boot CPU, once with a bogus timeout
 323 * value, second time for real. The other (noncalibrating) CPUs
 324 * call this function only once, with the real, calibrated value.
 325 *
 326 * We do reads before writes even if unnecessary, to get around the
 327 * P5 APIC double write bug.
 328 */
 329static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
 330{
 331	unsigned int lvtt_value, tmp_value;
 332
 333	lvtt_value = LOCAL_TIMER_VECTOR;
 334	if (!oneshot)
 335		lvtt_value |= APIC_LVT_TIMER_PERIODIC;
 336	else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
 337		lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
 338
 
 
 
 
 
 
 339	if (!lapic_is_integrated())
 340		lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
 341
 342	if (!irqen)
 343		lvtt_value |= APIC_LVT_MASKED;
 344
 345	apic_write(APIC_LVTT, lvtt_value);
 346
 347	if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
 348		/*
 349		 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
 350		 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
 351		 * According to Intel, MFENCE can do the serialization here.
 352		 */
 353		asm volatile("mfence" : : : "memory");
 354
 355		printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
 356		return;
 357	}
 358
 359	/*
 360	 * Divide PICLK by 16
 361	 */
 362	tmp_value = apic_read(APIC_TDCR);
 363	apic_write(APIC_TDCR,
 364		(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
 365		APIC_TDR_DIV_16);
 366
 367	if (!oneshot)
 368		apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
 369}
 370
 371/*
 372 * Setup extended LVT, AMD specific
 373 *
 374 * Software should use the LVT offsets the BIOS provides.  The offsets
 375 * are determined by the subsystems using it like those for MCE
 376 * threshold or IBS.  On K8 only offset 0 (APIC500) and MCE interrupts
 377 * are supported. Beginning with family 10h at least 4 offsets are
 378 * available.
 379 *
 380 * Since the offsets must be consistent for all cores, we keep track
 381 * of the LVT offsets in software and reserve the offset for the same
 382 * vector also to be used on other cores. An offset is freed by
 383 * setting the entry to APIC_EILVT_MASKED.
 384 *
 385 * If the BIOS is right, there should be no conflicts. Otherwise a
 386 * "[Firmware Bug]: ..." error message is generated. However, if
 387 * software does not properly determines the offsets, it is not
 388 * necessarily a BIOS bug.
 389 */
 390
 391static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
 392
 393static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
 394{
 395	return (old & APIC_EILVT_MASKED)
 396		|| (new == APIC_EILVT_MASKED)
 397		|| ((new & ~APIC_EILVT_MASKED) == old);
 398}
 399
 400static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
 401{
 402	unsigned int rsvd, vector;
 403
 404	if (offset >= APIC_EILVT_NR_MAX)
 405		return ~0;
 406
 407	rsvd = atomic_read(&eilvt_offsets[offset]);
 408	do {
 409		vector = rsvd & ~APIC_EILVT_MASKED;	/* 0: unassigned */
 410		if (vector && !eilvt_entry_is_changeable(vector, new))
 411			/* may not change if vectors are different */
 412			return rsvd;
 413		rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
 414	} while (rsvd != new);
 415
 416	rsvd &= ~APIC_EILVT_MASKED;
 417	if (rsvd && rsvd != vector)
 418		pr_info("LVT offset %d assigned for vector 0x%02x\n",
 419			offset, rsvd);
 420
 421	return new;
 422}
 423
 424/*
 425 * If mask=1, the LVT entry does not generate interrupts while mask=0
 426 * enables the vector. See also the BKDGs. Must be called with
 427 * preemption disabled.
 428 */
 429
 430int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
 431{
 432	unsigned long reg = APIC_EILVTn(offset);
 433	unsigned int new, old, reserved;
 434
 435	new = (mask << 16) | (msg_type << 8) | vector;
 436	old = apic_read(reg);
 437	reserved = reserve_eilvt_offset(offset, new);
 438
 439	if (reserved != new) {
 440		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
 441		       "vector 0x%x, but the register is already in use for "
 442		       "vector 0x%x on another cpu\n",
 443		       smp_processor_id(), reg, offset, new, reserved);
 444		return -EINVAL;
 445	}
 446
 447	if (!eilvt_entry_is_changeable(old, new)) {
 448		pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
 449		       "vector 0x%x, but the register is already in use for "
 450		       "vector 0x%x on this cpu\n",
 451		       smp_processor_id(), reg, offset, new, old);
 452		return -EBUSY;
 453	}
 454
 455	apic_write(reg, new);
 456
 457	return 0;
 458}
 459EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
 460
 461/*
 462 * Program the next event, relative to now
 463 */
 464static int lapic_next_event(unsigned long delta,
 465			    struct clock_event_device *evt)
 466{
 467	apic_write(APIC_TMICT, delta);
 468	return 0;
 469}
 470
 471static int lapic_next_deadline(unsigned long delta,
 472			       struct clock_event_device *evt)
 473{
 474	u64 tsc;
 475
 
 
 
 476	tsc = rdtsc();
 477	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
 478	return 0;
 479}
 480
 481static int lapic_timer_shutdown(struct clock_event_device *evt)
 482{
 483	unsigned int v;
 484
 485	/* Lapic used as dummy for broadcast ? */
 486	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
 487		return 0;
 488
 489	v = apic_read(APIC_LVTT);
 490	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
 491	apic_write(APIC_LVTT, v);
 492	apic_write(APIC_TMICT, 0);
 493	return 0;
 494}
 495
 496static inline int
 497lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
 498{
 499	/* Lapic used as dummy for broadcast ? */
 500	if (evt->features & CLOCK_EVT_FEAT_DUMMY)
 501		return 0;
 502
 503	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
 504	return 0;
 505}
 506
 507static int lapic_timer_set_periodic(struct clock_event_device *evt)
 508{
 509	return lapic_timer_set_periodic_oneshot(evt, false);
 510}
 511
 512static int lapic_timer_set_oneshot(struct clock_event_device *evt)
 513{
 514	return lapic_timer_set_periodic_oneshot(evt, true);
 515}
 516
 517/*
 518 * Local APIC timer broadcast function
 519 */
 520static void lapic_timer_broadcast(const struct cpumask *mask)
 521{
 522#ifdef CONFIG_SMP
 523	apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
 524#endif
 525}
 526
 527
 528/*
 529 * The local apic timer can be used for any function which is CPU local.
 530 */
 531static struct clock_event_device lapic_clockevent = {
 532	.name			= "lapic",
 533	.features		= CLOCK_EVT_FEAT_PERIODIC |
 534				  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
 535				  | CLOCK_EVT_FEAT_DUMMY,
 536	.shift			= 32,
 537	.set_state_shutdown	= lapic_timer_shutdown,
 538	.set_state_periodic	= lapic_timer_set_periodic,
 539	.set_state_oneshot	= lapic_timer_set_oneshot,
 540	.set_next_event		= lapic_next_event,
 541	.broadcast		= lapic_timer_broadcast,
 542	.rating			= 100,
 543	.irq			= -1,
 
 544};
 545static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
 546
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 547/*
 548 * Setup the local APIC timer for this CPU. Copy the initialized values
 549 * of the boot CPU and register the clock event in the framework.
 550 */
 551static void setup_APIC_timer(void)
 552{
 553	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 554
 555	if (this_cpu_has(X86_FEATURE_ARAT)) {
 556		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
 557		/* Make LAPIC timer preferrable over percpu HPET */
 558		lapic_clockevent.rating = 150;
 559	}
 560
 561	memcpy(levt, &lapic_clockevent, sizeof(*levt));
 562	levt->cpumask = cpumask_of(smp_processor_id());
 563
 564	if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
 
 565		levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
 566				    CLOCK_EVT_FEAT_DUMMY);
 567		levt->set_next_event = lapic_next_deadline;
 568		clockevents_config_and_register(levt,
 569						tsc_khz * (1000 / TSC_DIVISOR),
 570						0xF, ~0UL);
 571	} else
 572		clockevents_register_device(levt);
 573}
 574
 575/*
 576 * Install the updated TSC frequency from recalibration at the TSC
 577 * deadline clockevent devices.
 578 */
 579static void __lapic_update_tsc_freq(void *info)
 580{
 581	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 582
 583	if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
 584		return;
 585
 586	clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
 587}
 588
 589void lapic_update_tsc_freq(void)
 590{
 591	/*
 592	 * The clockevent device's ->mult and ->shift can both be
 593	 * changed. In order to avoid races, schedule the frequency
 594	 * update code on each CPU.
 595	 */
 596	on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
 597}
 598
 599/*
 600 * In this functions we calibrate APIC bus clocks to the external timer.
 601 *
 602 * We want to do the calibration only once since we want to have local timer
 603 * irqs syncron. CPUs connected by the same APIC bus have the very same bus
 604 * frequency.
 605 *
 606 * This was previously done by reading the PIT/HPET and waiting for a wrap
 607 * around to find out, that a tick has elapsed. I have a box, where the PIT
 608 * readout is broken, so it never gets out of the wait loop again. This was
 609 * also reported by others.
 610 *
 611 * Monitoring the jiffies value is inaccurate and the clockevents
 612 * infrastructure allows us to do a simple substitution of the interrupt
 613 * handler.
 614 *
 615 * The calibration routine also uses the pm_timer when possible, as the PIT
 616 * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
 617 * back to normal later in the boot process).
 618 */
 619
 620#define LAPIC_CAL_LOOPS		(HZ/10)
 621
 622static __initdata int lapic_cal_loops = -1;
 623static __initdata long lapic_cal_t1, lapic_cal_t2;
 624static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
 625static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
 626static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
 627
 628/*
 629 * Temporary interrupt handler.
 630 */
 631static void __init lapic_cal_handler(struct clock_event_device *dev)
 632{
 633	unsigned long long tsc = 0;
 634	long tapic = apic_read(APIC_TMCCT);
 635	unsigned long pm = acpi_pm_read_early();
 636
 637	if (boot_cpu_has(X86_FEATURE_TSC))
 638		tsc = rdtsc();
 639
 640	switch (lapic_cal_loops++) {
 641	case 0:
 642		lapic_cal_t1 = tapic;
 643		lapic_cal_tsc1 = tsc;
 644		lapic_cal_pm1 = pm;
 645		lapic_cal_j1 = jiffies;
 646		break;
 647
 648	case LAPIC_CAL_LOOPS:
 649		lapic_cal_t2 = tapic;
 650		lapic_cal_tsc2 = tsc;
 651		if (pm < lapic_cal_pm1)
 652			pm += ACPI_PM_OVRRUN;
 653		lapic_cal_pm2 = pm;
 654		lapic_cal_j2 = jiffies;
 655		break;
 656	}
 657}
 658
 659static int __init
 660calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
 661{
 662	const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
 663	const long pm_thresh = pm_100ms / 100;
 664	unsigned long mult;
 665	u64 res;
 666
 667#ifndef CONFIG_X86_PM_TIMER
 668	return -1;
 669#endif
 670
 671	apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
 672
 673	/* Check, if the PM timer is available */
 674	if (!deltapm)
 675		return -1;
 676
 677	mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
 678
 679	if (deltapm > (pm_100ms - pm_thresh) &&
 680	    deltapm < (pm_100ms + pm_thresh)) {
 681		apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
 682		return 0;
 683	}
 684
 685	res = (((u64)deltapm) *  mult) >> 22;
 686	do_div(res, 1000000);
 687	pr_warning("APIC calibration not consistent "
 688		   "with PM-Timer: %ldms instead of 100ms\n",(long)res);
 689
 690	/* Correct the lapic counter value */
 691	res = (((u64)(*delta)) * pm_100ms);
 692	do_div(res, deltapm);
 693	pr_info("APIC delta adjusted to PM-Timer: "
 694		"%lu (%ld)\n", (unsigned long)res, *delta);
 695	*delta = (long)res;
 696
 697	/* Correct the tsc counter value */
 698	if (boot_cpu_has(X86_FEATURE_TSC)) {
 699		res = (((u64)(*deltatsc)) * pm_100ms);
 700		do_div(res, deltapm);
 701		apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
 702					  "PM-Timer: %lu (%ld)\n",
 703					(unsigned long)res, *deltatsc);
 704		*deltatsc = (long)res;
 705	}
 706
 707	return 0;
 708}
 709
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 710static int __init calibrate_APIC_clock(void)
 711{
 712	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 713	void (*real_handler)(struct clock_event_device *dev);
 
 714	unsigned long deltaj;
 715	long delta, deltatsc;
 716	int pm_referenced = 0;
 717
 718	/**
 719	 * check if lapic timer has already been calibrated by platform
 720	 * specific routine, such as tsc calibration code. if so, we just fill
 
 
 
 721	 * in the clockevent structure and return.
 722	 */
 723
 724	if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
 725		return 0;
 726	} else if (lapic_timer_frequency) {
 727		apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
 728				lapic_timer_frequency);
 729		lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
 730					TICK_NSEC, lapic_clockevent.shift);
 731		lapic_clockevent.max_delta_ns =
 732			clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
 733		lapic_clockevent.min_delta_ns =
 734			clockevent_delta2ns(0xF, &lapic_clockevent);
 735		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
 736		return 0;
 737	}
 738
 739	apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
 740		    "calibrating APIC timer ...\n");
 741
 
 
 
 
 
 742	local_irq_disable();
 743
 744	/* Replace the global interrupt handler */
 745	real_handler = global_clock_event->event_handler;
 746	global_clock_event->event_handler = lapic_cal_handler;
 747
 748	/*
 749	 * Setup the APIC counter to maximum. There is no way the lapic
 750	 * can underflow in the 100ms detection time frame
 751	 */
 752	__setup_APIC_LVTT(0xffffffff, 0, 0);
 753
 754	/* Let the interrupts run */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 755	local_irq_enable();
 756
 757	while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
 758		cpu_relax();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 759
 760	local_irq_disable();
 761
 762	/* Restore the real event handler */
 763	global_clock_event->event_handler = real_handler;
 764
 765	/* Build delta t1-t2 as apic timer counts down */
 766	delta = lapic_cal_t1 - lapic_cal_t2;
 767	apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
 768
 769	deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
 770
 771	/* we trust the PM based calibration if possible */
 772	pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
 773					&delta, &deltatsc);
 774
 775	/* Calculate the scaled math multiplication factor */
 776	lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
 777				       lapic_clockevent.shift);
 778	lapic_clockevent.max_delta_ns =
 779		clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
 780	lapic_clockevent.min_delta_ns =
 781		clockevent_delta2ns(0xF, &lapic_clockevent);
 782
 783	lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
 784
 785	apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
 786	apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
 787	apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
 788		    lapic_timer_frequency);
 789
 790	if (boot_cpu_has(X86_FEATURE_TSC)) {
 791		apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
 792			    "%ld.%04ld MHz.\n",
 793			    (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
 794			    (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
 795	}
 796
 797	apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
 798		    "%u.%04u MHz.\n",
 799		    lapic_timer_frequency / (1000000 / HZ),
 800		    lapic_timer_frequency % (1000000 / HZ));
 801
 802	/*
 803	 * Do a sanity check on the APIC calibration result
 804	 */
 805	if (lapic_timer_frequency < (1000000 / HZ)) {
 806		local_irq_enable();
 807		pr_warning("APIC frequency too slow, disabling apic timer\n");
 808		return -1;
 809	}
 810
 811	levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
 812
 813	/*
 814	 * PM timer calibration failed or not turned on
 815	 * so lets try APIC timer based calibration
 
 816	 */
 817	if (!pm_referenced) {
 818		apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
 819
 820		/*
 821		 * Setup the apic timer manually
 822		 */
 823		levt->event_handler = lapic_cal_handler;
 824		lapic_timer_set_periodic(levt);
 825		lapic_cal_loops = -1;
 826
 827		/* Let the interrupts run */
 828		local_irq_enable();
 829
 830		while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
 831			cpu_relax();
 832
 833		/* Stop the lapic timer */
 834		local_irq_disable();
 835		lapic_timer_shutdown(levt);
 836
 837		/* Jiffies delta */
 838		deltaj = lapic_cal_j2 - lapic_cal_j1;
 839		apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
 840
 841		/* Check, if the jiffies result is consistent */
 842		if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
 843			apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
 844		else
 845			levt->features |= CLOCK_EVT_FEAT_DUMMY;
 846	}
 847	local_irq_enable();
 848
 849	if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
 850		pr_warning("APIC timer disabled due to verification failure\n");
 851			return -1;
 852	}
 853
 854	return 0;
 855}
 856
 857/*
 858 * Setup the boot APIC
 859 *
 860 * Calibrate and verify the result.
 861 */
 862void __init setup_boot_APIC_clock(void)
 863{
 864	/*
 865	 * The local apic timer can be disabled via the kernel
 866	 * commandline or from the CPU detection code. Register the lapic
 867	 * timer as a dummy clock event source on SMP systems, so the
 868	 * broadcast mechanism is used. On UP systems simply ignore it.
 869	 */
 870	if (disable_apic_timer) {
 871		pr_info("Disabling APIC timer\n");
 872		/* No broadcast on UP ! */
 873		if (num_possible_cpus() > 1) {
 874			lapic_clockevent.mult = 1;
 875			setup_APIC_timer();
 876		}
 877		return;
 878	}
 879
 880	if (calibrate_APIC_clock()) {
 881		/* No broadcast on UP ! */
 882		if (num_possible_cpus() > 1)
 883			setup_APIC_timer();
 884		return;
 885	}
 886
 887	/*
 888	 * If nmi_watchdog is set to IO_APIC, we need the
 889	 * PIT/HPET going.  Otherwise register lapic as a dummy
 890	 * device.
 891	 */
 892	lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
 893
 894	/* Setup the lapic or request the broadcast */
 895	setup_APIC_timer();
 896	amd_e400_c1e_apic_setup();
 897}
 898
 899void setup_secondary_APIC_clock(void)
 900{
 901	setup_APIC_timer();
 902	amd_e400_c1e_apic_setup();
 903}
 904
 905/*
 906 * The guts of the apic timer interrupt
 907 */
 908static void local_apic_timer_interrupt(void)
 909{
 910	int cpu = smp_processor_id();
 911	struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
 912
 913	/*
 914	 * Normally we should not be here till LAPIC has been initialized but
 915	 * in some cases like kdump, its possible that there is a pending LAPIC
 916	 * timer interrupt from previous kernel's context and is delivered in
 917	 * new kernel the moment interrupts are enabled.
 918	 *
 919	 * Interrupts are enabled early and LAPIC is setup much later, hence
 920	 * its possible that when we get here evt->event_handler is NULL.
 921	 * Check for event_handler being NULL and discard the interrupt as
 922	 * spurious.
 923	 */
 924	if (!evt->event_handler) {
 925		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
 
 926		/* Switch it off */
 927		lapic_timer_shutdown(evt);
 928		return;
 929	}
 930
 931	/*
 932	 * the NMI deadlock-detector uses this.
 933	 */
 934	inc_irq_stat(apic_timer_irqs);
 935
 936	evt->event_handler(evt);
 937}
 938
 939/*
 940 * Local APIC timer interrupt. This is the most natural way for doing
 941 * local interrupts, but local timer interrupts can be emulated by
 942 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
 943 *
 944 * [ if a single-CPU system runs an SMP kernel then we call the local
 945 *   interrupt as well. Thus we cannot inline the local irq ... ]
 946 */
 947__visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
 948{
 949	struct pt_regs *old_regs = set_irq_regs(regs);
 950
 951	/*
 952	 * NOTE! We'd better ACK the irq immediately,
 953	 * because timer handling can be slow.
 954	 *
 955	 * update_process_times() expects us to have done irq_enter().
 956	 * Besides, if we don't timer interrupts ignore the global
 957	 * interrupt lock, which is the WrongThing (tm) to do.
 958	 */
 959	entering_ack_irq();
 960	local_apic_timer_interrupt();
 961	exiting_irq();
 962
 963	set_irq_regs(old_regs);
 964}
 965
 966__visible void __irq_entry smp_trace_apic_timer_interrupt(struct pt_regs *regs)
 967{
 968	struct pt_regs *old_regs = set_irq_regs(regs);
 969
 970	/*
 971	 * NOTE! We'd better ACK the irq immediately,
 972	 * because timer handling can be slow.
 973	 *
 974	 * update_process_times() expects us to have done irq_enter().
 975	 * Besides, if we don't timer interrupts ignore the global
 976	 * interrupt lock, which is the WrongThing (tm) to do.
 977	 */
 978	entering_ack_irq();
 979	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
 980	local_apic_timer_interrupt();
 981	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
 982	exiting_irq();
 983
 984	set_irq_regs(old_regs);
 985}
 986
 987int setup_profiling_timer(unsigned int multiplier)
 988{
 989	return -EINVAL;
 990}
 991
 992/*
 993 * Local APIC start and shutdown
 994 */
 995
 996/**
 997 * clear_local_APIC - shutdown the local APIC
 998 *
 999 * This is called, when a CPU is disabled and before rebooting, so the state of
1000 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1001 * leftovers during boot.
1002 */
1003void clear_local_APIC(void)
1004{
1005	int maxlvt;
1006	u32 v;
1007
1008	/* APIC hasn't been mapped yet */
1009	if (!x2apic_mode && !apic_phys)
1010		return;
1011
1012	maxlvt = lapic_get_maxlvt();
1013	/*
1014	 * Masking an LVT entry can trigger a local APIC error
1015	 * if the vector is zero. Mask LVTERR first to prevent this.
1016	 */
1017	if (maxlvt >= 3) {
1018		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1019		apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1020	}
1021	/*
1022	 * Careful: we have to set masks only first to deassert
1023	 * any level-triggered sources.
1024	 */
1025	v = apic_read(APIC_LVTT);
1026	apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1027	v = apic_read(APIC_LVT0);
1028	apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1029	v = apic_read(APIC_LVT1);
1030	apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1031	if (maxlvt >= 4) {
1032		v = apic_read(APIC_LVTPC);
1033		apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1034	}
1035
1036	/* lets not touch this if we didn't frob it */
1037#ifdef CONFIG_X86_THERMAL_VECTOR
1038	if (maxlvt >= 5) {
1039		v = apic_read(APIC_LVTTHMR);
1040		apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1041	}
1042#endif
1043#ifdef CONFIG_X86_MCE_INTEL
1044	if (maxlvt >= 6) {
1045		v = apic_read(APIC_LVTCMCI);
1046		if (!(v & APIC_LVT_MASKED))
1047			apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1048	}
1049#endif
1050
1051	/*
1052	 * Clean APIC state for other OSs:
1053	 */
1054	apic_write(APIC_LVTT, APIC_LVT_MASKED);
1055	apic_write(APIC_LVT0, APIC_LVT_MASKED);
1056	apic_write(APIC_LVT1, APIC_LVT_MASKED);
1057	if (maxlvt >= 3)
1058		apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1059	if (maxlvt >= 4)
1060		apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1061
1062	/* Integrated APIC (!82489DX) ? */
1063	if (lapic_is_integrated()) {
1064		if (maxlvt > 3)
1065			/* Clear ESR due to Pentium errata 3AP and 11AP */
1066			apic_write(APIC_ESR, 0);
1067		apic_read(APIC_ESR);
1068	}
1069}
1070
1071/**
1072 * disable_local_APIC - clear and disable the local APIC
 
 
 
 
 
 
 
 
1073 */
1074void disable_local_APIC(void)
1075{
1076	unsigned int value;
1077
1078	/* APIC hasn't been mapped yet */
1079	if (!x2apic_mode && !apic_phys)
1080		return;
1081
1082	clear_local_APIC();
1083
1084	/*
1085	 * Disable APIC (implies clearing of registers
1086	 * for 82489DX!).
1087	 */
1088	value = apic_read(APIC_SPIV);
1089	value &= ~APIC_SPIV_APIC_ENABLED;
1090	apic_write(APIC_SPIV, value);
 
 
 
 
 
 
 
 
 
 
 
1091
1092#ifdef CONFIG_X86_32
1093	/*
1094	 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1095	 * restore the disabled state.
1096	 */
1097	if (enabled_via_apicbase) {
1098		unsigned int l, h;
1099
1100		rdmsr(MSR_IA32_APICBASE, l, h);
1101		l &= ~MSR_IA32_APICBASE_ENABLE;
1102		wrmsr(MSR_IA32_APICBASE, l, h);
1103	}
1104#endif
1105}
1106
1107/*
1108 * If Linux enabled the LAPIC against the BIOS default disable it down before
1109 * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
1110 * not power-off.  Additionally clear all LVT entries before disable_local_APIC
1111 * for the case where Linux didn't enable the LAPIC.
1112 */
1113void lapic_shutdown(void)
1114{
1115	unsigned long flags;
1116
1117	if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1118		return;
1119
1120	local_irq_save(flags);
1121
1122#ifdef CONFIG_X86_32
1123	if (!enabled_via_apicbase)
1124		clear_local_APIC();
1125	else
1126#endif
1127		disable_local_APIC();
1128
1129
1130	local_irq_restore(flags);
1131}
1132
1133/**
1134 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1135 */
1136void __init sync_Arb_IDs(void)
1137{
1138	/*
1139	 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1140	 * needed on AMD.
1141	 */
1142	if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1143		return;
1144
1145	/*
1146	 * Wait for idle.
1147	 */
1148	apic_wait_icr_idle();
1149
1150	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1151	apic_write(APIC_ICR, APIC_DEST_ALLINC |
1152			APIC_INT_LEVELTRIG | APIC_DM_INIT);
1153}
1154
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1155/*
1156 * An initial setup of the virtual wire mode.
1157 */
1158void __init init_bsp_APIC(void)
1159{
1160	unsigned int value;
1161
1162	/*
1163	 * Don't do the setup now if we have a SMP BIOS as the
1164	 * through-I/O-APIC virtual wire mode might be active.
1165	 */
1166	if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1167		return;
1168
1169	/*
1170	 * Do not trust the local APIC being empty at bootup.
1171	 */
1172	clear_local_APIC();
1173
1174	/*
1175	 * Enable APIC.
1176	 */
1177	value = apic_read(APIC_SPIV);
1178	value &= ~APIC_VECTOR_MASK;
1179	value |= APIC_SPIV_APIC_ENABLED;
1180
1181#ifdef CONFIG_X86_32
1182	/* This bit is reserved on P4/Xeon and should be cleared */
1183	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1184	    (boot_cpu_data.x86 == 15))
1185		value &= ~APIC_SPIV_FOCUS_DISABLED;
1186	else
1187#endif
1188		value |= APIC_SPIV_FOCUS_DISABLED;
1189	value |= SPURIOUS_APIC_VECTOR;
1190	apic_write(APIC_SPIV, value);
1191
1192	/*
1193	 * Set up the virtual wire mode.
1194	 */
1195	apic_write(APIC_LVT0, APIC_DM_EXTINT);
1196	value = APIC_DM_NMI;
1197	if (!lapic_is_integrated())		/* 82489DX */
1198		value |= APIC_LVT_LEVEL_TRIGGER;
1199	if (apic_extnmi == APIC_EXTNMI_NONE)
1200		value |= APIC_LVT_MASKED;
1201	apic_write(APIC_LVT1, value);
1202}
1203
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1204static void lapic_setup_esr(void)
1205{
1206	unsigned int oldvalue, value, maxlvt;
1207
1208	if (!lapic_is_integrated()) {
1209		pr_info("No ESR for 82489DX.\n");
1210		return;
1211	}
1212
1213	if (apic->disable_esr) {
1214		/*
1215		 * Something untraceable is creating bad interrupts on
1216		 * secondary quads ... for the moment, just leave the
1217		 * ESR disabled - we can't do anything useful with the
1218		 * errors anyway - mbligh
1219		 */
1220		pr_info("Leaving ESR disabled.\n");
1221		return;
1222	}
1223
1224	maxlvt = lapic_get_maxlvt();
1225	if (maxlvt > 3)		/* Due to the Pentium erratum 3AP. */
1226		apic_write(APIC_ESR, 0);
1227	oldvalue = apic_read(APIC_ESR);
1228
1229	/* enables sending errors */
1230	value = ERROR_APIC_VECTOR;
1231	apic_write(APIC_LVTERR, value);
1232
1233	/*
1234	 * spec says clear errors after enabling vector.
1235	 */
1236	if (maxlvt > 3)
1237		apic_write(APIC_ESR, 0);
1238	value = apic_read(APIC_ESR);
1239	if (value != oldvalue)
1240		apic_printk(APIC_VERBOSE, "ESR value before enabling "
1241			"vector: 0x%08x  after: 0x%08x\n",
1242			oldvalue, value);
1243}
1244
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1245/**
1246 * setup_local_APIC - setup the local APIC
1247 *
1248 * Used to setup local APIC while initializing BSP or bringin up APs.
1249 * Always called with preemption disabled.
1250 */
1251void setup_local_APIC(void)
1252{
1253	int cpu = smp_processor_id();
1254	unsigned int value, queued;
1255	int i, j, acked = 0;
1256	unsigned long long tsc = 0, ntsc;
1257	long long max_loops = cpu_khz ? cpu_khz : 1000000;
1258
1259	if (boot_cpu_has(X86_FEATURE_TSC))
1260		tsc = rdtsc();
1261
1262	if (disable_apic) {
1263		disable_ioapic_support();
1264		return;
1265	}
1266
 
 
 
 
 
 
 
 
1267#ifdef CONFIG_X86_32
1268	/* Pound the ESR really hard over the head with a big hammer - mbligh */
1269	if (lapic_is_integrated() && apic->disable_esr) {
1270		apic_write(APIC_ESR, 0);
1271		apic_write(APIC_ESR, 0);
1272		apic_write(APIC_ESR, 0);
1273		apic_write(APIC_ESR, 0);
1274	}
1275#endif
1276	perf_events_lapic_init();
1277
1278	/*
1279	 * Double-check whether this APIC is really registered.
1280	 * This is meaningless in clustered apic mode, so we skip it.
1281	 */
1282	BUG_ON(!apic->apic_id_registered());
1283
1284	/*
1285	 * Intel recommends to set DFR, LDR and TPR before enabling
1286	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
1287	 * document number 292116).  So here it goes...
1288	 */
1289	apic->init_apic_ldr();
1290
1291#ifdef CONFIG_X86_32
1292	/*
1293	 * APIC LDR is initialized.  If logical_apicid mapping was
1294	 * initialized during get_smp_config(), make sure it matches the
1295	 * actual value.
1296	 */
1297	i = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1298	WARN_ON(i != BAD_APICID && i != logical_smp_processor_id());
1299	/* always use the value from LDR */
1300	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1301		logical_smp_processor_id();
1302#endif
1303
1304	/*
1305	 * Set Task Priority to 'accept all'. We never change this
1306	 * later on.
 
 
1307	 */
1308	value = apic_read(APIC_TASKPRI);
1309	value &= ~APIC_TPRI_MASK;
 
1310	apic_write(APIC_TASKPRI, value);
1311
1312	/*
1313	 * After a crash, we no longer service the interrupts and a pending
1314	 * interrupt from previous kernel might still have ISR bit set.
1315	 *
1316	 * Most probably by now CPU has serviced that pending interrupt and
1317	 * it might not have done the ack_APIC_irq() because it thought,
1318	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1319	 * does not clear the ISR bit and cpu thinks it has already serivced
1320	 * the interrupt. Hence a vector might get locked. It was noticed
1321	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1322	 */
1323	do {
1324		queued = 0;
1325		for (i = APIC_ISR_NR - 1; i >= 0; i--)
1326			queued |= apic_read(APIC_IRR + i*0x10);
1327
1328		for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1329			value = apic_read(APIC_ISR + i*0x10);
1330			for (j = 31; j >= 0; j--) {
1331				if (value & (1<<j)) {
1332					ack_APIC_irq();
1333					acked++;
1334				}
1335			}
1336		}
1337		if (acked > 256) {
1338			printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
1339			       acked);
1340			break;
1341		}
1342		if (queued) {
1343			if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) {
1344				ntsc = rdtsc();
1345				max_loops = (cpu_khz << 10) - (ntsc - tsc);
1346			} else
1347				max_loops--;
1348		}
1349	} while (queued && max_loops > 0);
1350	WARN_ON(max_loops <= 0);
1351
1352	/*
1353	 * Now that we are all set up, enable the APIC
1354	 */
1355	value = apic_read(APIC_SPIV);
1356	value &= ~APIC_VECTOR_MASK;
1357	/*
1358	 * Enable APIC
1359	 */
1360	value |= APIC_SPIV_APIC_ENABLED;
1361
1362#ifdef CONFIG_X86_32
1363	/*
1364	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1365	 * certain networking cards. If high frequency interrupts are
1366	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1367	 * entry is masked/unmasked at a high rate as well then sooner or
1368	 * later IOAPIC line gets 'stuck', no more interrupts are received
1369	 * from the device. If focus CPU is disabled then the hang goes
1370	 * away, oh well :-(
1371	 *
1372	 * [ This bug can be reproduced easily with a level-triggered
1373	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
1374	 *   BX chipset. ]
1375	 */
1376	/*
1377	 * Actually disabling the focus CPU check just makes the hang less
1378	 * frequent as it makes the interrupt distributon model be more
1379	 * like LRU than MRU (the short-term load is more even across CPUs).
1380	 */
1381
1382	/*
1383	 * - enable focus processor (bit==0)
1384	 * - 64bit mode always use processor focus
1385	 *   so no need to set it
1386	 */
1387	value &= ~APIC_SPIV_FOCUS_DISABLED;
1388#endif
1389
1390	/*
1391	 * Set spurious IRQ vector
1392	 */
1393	value |= SPURIOUS_APIC_VECTOR;
1394	apic_write(APIC_SPIV, value);
1395
 
 
1396	/*
1397	 * Set up LVT0, LVT1:
1398	 *
1399	 * set up through-local-APIC on the BP's LINT0. This is not
1400	 * strictly necessary in pure symmetric-IO mode, but sometimes
1401	 * we delegate interrupts to the 8259A.
1402	 */
1403	/*
1404	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1405	 */
1406	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1407	if (!cpu && (pic_mode || !value)) {
1408		value = APIC_DM_EXTINT;
1409		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1410	} else {
1411		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1412		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1413	}
1414	apic_write(APIC_LVT0, value);
1415
1416	/*
1417	 * Only the BSP sees the LINT1 NMI signal by default. This can be
1418	 * modified by apic_extnmi= boot option.
1419	 */
1420	if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1421	    apic_extnmi == APIC_EXTNMI_ALL)
1422		value = APIC_DM_NMI;
1423	else
1424		value = APIC_DM_NMI | APIC_LVT_MASKED;
1425	if (!lapic_is_integrated())		/* 82489DX */
 
 
1426		value |= APIC_LVT_LEVEL_TRIGGER;
1427	apic_write(APIC_LVT1, value);
1428
1429#ifdef CONFIG_X86_MCE_INTEL
1430	/* Recheck CMCI information after local APIC is up on CPU #0 */
1431	if (!cpu)
1432		cmci_recheck();
1433#endif
1434}
1435
1436static void end_local_APIC_setup(void)
1437{
1438	lapic_setup_esr();
1439
1440#ifdef CONFIG_X86_32
1441	{
1442		unsigned int value;
1443		/* Disable the local apic timer */
1444		value = apic_read(APIC_LVTT);
1445		value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1446		apic_write(APIC_LVTT, value);
1447	}
1448#endif
1449
1450	apic_pm_activate();
1451}
1452
1453/*
1454 * APIC setup function for application processors. Called from smpboot.c
1455 */
1456void apic_ap_setup(void)
1457{
1458	setup_local_APIC();
1459	end_local_APIC_setup();
1460}
1461
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1462#ifdef CONFIG_X86_X2APIC
1463int x2apic_mode;
 
1464
1465enum {
1466	X2APIC_OFF,
 
 
1467	X2APIC_ON,
1468	X2APIC_DISABLED,
1469};
1470static int x2apic_state;
1471
 
 
 
 
 
 
 
 
 
 
 
 
 
1472static void __x2apic_disable(void)
1473{
1474	u64 msr;
1475
1476	if (!boot_cpu_has(X86_FEATURE_APIC))
1477		return;
1478
1479	rdmsrl(MSR_IA32_APICBASE, msr);
1480	if (!(msr & X2APIC_ENABLE))
1481		return;
1482	/* Disable xapic and x2apic first and then reenable xapic mode */
1483	wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1484	wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1485	printk_once(KERN_INFO "x2apic disabled\n");
1486}
1487
1488static void __x2apic_enable(void)
1489{
1490	u64 msr;
1491
1492	rdmsrl(MSR_IA32_APICBASE, msr);
1493	if (msr & X2APIC_ENABLE)
1494		return;
1495	wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1496	printk_once(KERN_INFO "x2apic enabled\n");
1497}
1498
1499static int __init setup_nox2apic(char *str)
1500{
1501	if (x2apic_enabled()) {
1502		int apicid = native_apic_msr_read(APIC_ID);
1503
1504		if (apicid >= 255) {
1505			pr_warning("Apicid: %08x, cannot enforce nox2apic\n",
1506				   apicid);
1507			return 0;
1508		}
1509		pr_warning("x2apic already enabled.\n");
 
 
 
 
1510		__x2apic_disable();
1511	}
1512	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1513	x2apic_state = X2APIC_DISABLED;
1514	x2apic_mode = 0;
1515	return 0;
1516}
1517early_param("nox2apic", setup_nox2apic);
1518
1519/* Called from cpu_init() to enable x2apic on (secondary) cpus */
1520void x2apic_setup(void)
1521{
1522	/*
1523	 * If x2apic is not in ON state, disable it if already enabled
 
 
 
 
 
 
 
 
1524	 * from BIOS.
1525	 */
1526	if (x2apic_state != X2APIC_ON) {
1527		__x2apic_disable();
1528		return;
1529	}
1530	__x2apic_enable();
1531}
1532
 
 
1533static __init void x2apic_disable(void)
1534{
1535	u32 x2apic_id, state = x2apic_state;
1536
1537	x2apic_mode = 0;
1538	x2apic_state = X2APIC_DISABLED;
1539
1540	if (state != X2APIC_ON)
1541		return;
1542
1543	x2apic_id = read_apic_id();
1544	if (x2apic_id >= 255)
1545		panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1546
 
 
 
 
 
1547	__x2apic_disable();
1548	register_lapic_address(mp_lapic_addr);
1549}
1550
1551static __init void x2apic_enable(void)
1552{
1553	if (x2apic_state != X2APIC_OFF)
1554		return;
1555
1556	x2apic_mode = 1;
1557	x2apic_state = X2APIC_ON;
1558	__x2apic_enable();
1559}
1560
1561static __init void try_to_enable_x2apic(int remap_mode)
1562{
1563	if (x2apic_state == X2APIC_DISABLED)
1564		return;
1565
1566	if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1567		/* IR is required if there is APIC ID > 255 even when running
1568		 * under KVM
 
 
 
1569		 */
1570		if (max_physical_apicid > 255 ||
1571		    !hypervisor_x2apic_available()) {
1572			pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1573			x2apic_disable();
1574			return;
1575		}
1576
1577		/*
1578		 * without IR all CPUs can be addressed by IOAPIC/MSI
1579		 * only in physical mode
 
 
 
 
 
 
 
 
 
 
 
1580		 */
 
1581		x2apic_phys = 1;
1582	}
1583	x2apic_enable();
1584}
1585
1586void __init check_x2apic(void)
1587{
1588	if (x2apic_enabled()) {
1589		pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1590		x2apic_mode = 1;
1591		x2apic_state = X2APIC_ON;
 
 
 
 
1592	} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1593		x2apic_state = X2APIC_DISABLED;
1594	}
1595}
1596#else /* CONFIG_X86_X2APIC */
1597static int __init validate_x2apic(void)
1598{
1599	if (!apic_is_x2apic_enabled())
1600		return 0;
1601	/*
1602	 * Checkme: Can we simply turn off x2apic here instead of panic?
1603	 */
1604	panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
 
 
 
 
1605}
1606early_initcall(validate_x2apic);
1607
1608static inline void try_to_enable_x2apic(int remap_mode) { }
1609static inline void __x2apic_enable(void) { }
1610#endif /* !CONFIG_X86_X2APIC */
1611
1612static int __init try_to_enable_IR(void)
1613{
1614#ifdef CONFIG_X86_IO_APIC
1615	if (!x2apic_enabled() && skip_ioapic_setup) {
1616		pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1617		return -1;
1618	}
1619#endif
1620	return irq_remapping_enable();
1621}
1622
1623void __init enable_IR_x2apic(void)
1624{
1625	unsigned long flags;
1626	int ret, ir_stat;
1627
1628	if (skip_ioapic_setup)
 
1629		return;
 
1630
1631	ir_stat = irq_remapping_prepare();
1632	if (ir_stat < 0 && !x2apic_supported())
1633		return;
1634
1635	ret = save_ioapic_entries();
1636	if (ret) {
1637		pr_info("Saving IO-APIC state failed: %d\n", ret);
1638		return;
1639	}
1640
1641	local_irq_save(flags);
1642	legacy_pic->mask_all();
1643	mask_ioapic_entries();
1644
1645	/* If irq_remapping_prepare() succeeded, try to enable it */
1646	if (ir_stat >= 0)
1647		ir_stat = try_to_enable_IR();
1648	/* ir_stat contains the remap mode or an error code */
1649	try_to_enable_x2apic(ir_stat);
1650
1651	if (ir_stat < 0)
1652		restore_ioapic_entries();
1653	legacy_pic->restore_mask();
1654	local_irq_restore(flags);
1655}
1656
1657#ifdef CONFIG_X86_64
1658/*
1659 * Detect and enable local APICs on non-SMP boards.
1660 * Original code written by Keir Fraser.
1661 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1662 * not correctly set up (usually the APIC timer won't work etc.)
1663 */
1664static int __init detect_init_APIC(void)
1665{
1666	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1667		pr_info("No local APIC present\n");
1668		return -1;
1669	}
1670
1671	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1672	return 0;
1673}
1674#else
1675
1676static int __init apic_verify(void)
1677{
1678	u32 features, h, l;
1679
1680	/*
1681	 * The APIC feature bit should now be enabled
1682	 * in `cpuid'
1683	 */
1684	features = cpuid_edx(1);
1685	if (!(features & (1 << X86_FEATURE_APIC))) {
1686		pr_warning("Could not enable APIC!\n");
1687		return -1;
1688	}
1689	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1690	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1691
1692	/* The BIOS may have set up the APIC at some other address */
1693	if (boot_cpu_data.x86 >= 6) {
1694		rdmsr(MSR_IA32_APICBASE, l, h);
1695		if (l & MSR_IA32_APICBASE_ENABLE)
1696			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1697	}
1698
 
1699	pr_info("Found and enabled local APIC!\n");
1700	return 0;
1701}
1702
1703int __init apic_force_enable(unsigned long addr)
1704{
1705	u32 h, l;
1706
1707	if (disable_apic)
1708		return -1;
1709
1710	/*
1711	 * Some BIOSes disable the local APIC in the APIC_BASE
1712	 * MSR. This can only be done in software for Intel P6 or later
1713	 * and AMD K7 (Model > 1) or later.
1714	 */
1715	if (boot_cpu_data.x86 >= 6) {
1716		rdmsr(MSR_IA32_APICBASE, l, h);
1717		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1718			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1719			l &= ~MSR_IA32_APICBASE_BASE;
1720			l |= MSR_IA32_APICBASE_ENABLE | addr;
1721			wrmsr(MSR_IA32_APICBASE, l, h);
1722			enabled_via_apicbase = 1;
1723		}
1724	}
1725	return apic_verify();
1726}
1727
1728/*
1729 * Detect and initialize APIC
1730 */
1731static int __init detect_init_APIC(void)
1732{
1733	/* Disabled by kernel option? */
1734	if (disable_apic)
1735		return -1;
1736
1737	switch (boot_cpu_data.x86_vendor) {
1738	case X86_VENDOR_AMD:
1739		if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1740		    (boot_cpu_data.x86 >= 15))
1741			break;
1742		goto no_apic;
 
 
1743	case X86_VENDOR_INTEL:
1744		if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1745		    (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
1746			break;
1747		goto no_apic;
1748	default:
1749		goto no_apic;
1750	}
1751
1752	if (!boot_cpu_has(X86_FEATURE_APIC)) {
1753		/*
1754		 * Over-ride BIOS and try to enable the local APIC only if
1755		 * "lapic" specified.
1756		 */
1757		if (!force_enable_local_apic) {
1758			pr_info("Local APIC disabled by BIOS -- "
1759				"you can enable it with \"lapic\"\n");
1760			return -1;
1761		}
1762		if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1763			return -1;
1764	} else {
1765		if (apic_verify())
1766			return -1;
1767	}
1768
1769	apic_pm_activate();
1770
1771	return 0;
1772
1773no_apic:
1774	pr_info("No local APIC present or hardware disabled\n");
1775	return -1;
1776}
1777#endif
1778
1779/**
1780 * init_apic_mappings - initialize APIC mappings
1781 */
1782void __init init_apic_mappings(void)
1783{
1784	unsigned int new_apicid;
 
1785
1786	if (x2apic_mode) {
1787		boot_cpu_physical_apicid = read_apic_id();
1788		return;
1789	}
1790
1791	/* If no local APIC can be found return early */
1792	if (!smp_found_config && detect_init_APIC()) {
1793		/* lets NOP'ify apic operations */
1794		pr_info("APIC: disable apic facility\n");
1795		apic_disable();
1796	} else {
1797		apic_phys = mp_lapic_addr;
1798
1799		/*
1800		 * acpi lapic path already maps that address in
1801		 * acpi_register_lapic_address()
1802		 */
1803		if (!acpi_lapic && !smp_found_config)
1804			register_lapic_address(apic_phys);
1805	}
 
1806
1807	/*
1808	 * Fetch the APIC ID of the BSP in case we have a
1809	 * default configuration (or the MP table is broken).
1810	 */
1811	new_apicid = read_apic_id();
1812	if (boot_cpu_physical_apicid != new_apicid) {
1813		boot_cpu_physical_apicid = new_apicid;
1814		/*
1815		 * yeah -- we lie about apic_version
1816		 * in case if apic was disabled via boot option
1817		 * but it's not a problem for SMP compiled kernel
1818		 * since smp_sanity_check is prepared for such a case
1819		 * and disable smp mode
1820		 */
1821		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
1822	}
1823}
1824
1825void __init register_lapic_address(unsigned long address)
1826{
 
 
1827	mp_lapic_addr = address;
1828
1829	if (!x2apic_mode) {
1830		set_fixmap_nocache(FIX_APIC_BASE, address);
1831		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1832			    APIC_BASE, address);
1833	}
1834	if (boot_cpu_physical_apicid == -1U) {
1835		boot_cpu_physical_apicid  = read_apic_id();
1836		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
1837	}
1838}
1839
1840/*
1841 * Local APIC interrupts
1842 */
1843
1844/*
1845 * This interrupt should _never_ happen with our APIC/SMP architecture
 
1846 */
1847static void __smp_spurious_interrupt(u8 vector)
1848{
1849	u32 v;
1850
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1851	/*
1852	 * Check if this really is a spurious interrupt and ACK it
1853	 * if it is a vectored one.  Just in case...
1854	 * Spurious interrupts should not be ACKed.
1855	 */
1856	v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
1857	if (v & (1 << (vector & 0x1f)))
1858		ack_APIC_irq();
1859
1860	inc_irq_stat(irq_spurious_count);
1861
1862	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1863	pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
1864		"should never happen.\n", vector, smp_processor_id());
 
 
1865}
1866
1867__visible void smp_spurious_interrupt(struct pt_regs *regs)
 
 
 
 
 
 
 
 
 
1868{
1869	entering_irq();
1870	__smp_spurious_interrupt(~regs->orig_ax);
1871	exiting_irq();
1872}
1873
1874__visible void smp_trace_spurious_interrupt(struct pt_regs *regs)
1875{
1876	u8 vector = ~regs->orig_ax;
1877
1878	entering_irq();
1879	trace_spurious_apic_entry(vector);
1880	__smp_spurious_interrupt(vector);
1881	trace_spurious_apic_exit(vector);
1882	exiting_irq();
1883}
1884
1885/*
1886 * This interrupt should never happen with our APIC/SMP architecture
1887 */
1888static void __smp_error_interrupt(struct pt_regs *regs)
1889{
1890	u32 v;
1891	u32 i = 0;
1892	static const char * const error_interrupt_reason[] = {
1893		"Send CS error",		/* APIC Error Bit 0 */
1894		"Receive CS error",		/* APIC Error Bit 1 */
1895		"Send accept error",		/* APIC Error Bit 2 */
1896		"Receive accept error",		/* APIC Error Bit 3 */
1897		"Redirectable IPI",		/* APIC Error Bit 4 */
1898		"Send illegal vector",		/* APIC Error Bit 5 */
1899		"Received illegal vector",	/* APIC Error Bit 6 */
1900		"Illegal register address",	/* APIC Error Bit 7 */
1901	};
 
 
 
1902
1903	/* First tickle the hardware, only then report what went on. -- REW */
1904	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
1905		apic_write(APIC_ESR, 0);
1906	v = apic_read(APIC_ESR);
1907	ack_APIC_irq();
1908	atomic_inc(&irq_err_count);
1909
1910	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
1911		    smp_processor_id(), v);
1912
1913	v &= 0xff;
1914	while (v) {
1915		if (v & 0x1)
1916			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
1917		i++;
1918		v >>= 1;
1919	}
1920
1921	apic_printk(APIC_DEBUG, KERN_CONT "\n");
1922
1923}
1924
1925__visible void smp_error_interrupt(struct pt_regs *regs)
1926{
1927	entering_irq();
1928	__smp_error_interrupt(regs);
1929	exiting_irq();
1930}
1931
1932__visible void smp_trace_error_interrupt(struct pt_regs *regs)
1933{
1934	entering_irq();
1935	trace_error_apic_entry(ERROR_APIC_VECTOR);
1936	__smp_error_interrupt(regs);
1937	trace_error_apic_exit(ERROR_APIC_VECTOR);
1938	exiting_irq();
1939}
1940
1941/**
1942 * connect_bsp_APIC - attach the APIC to the interrupt system
1943 */
1944static void __init connect_bsp_APIC(void)
1945{
1946#ifdef CONFIG_X86_32
1947	if (pic_mode) {
1948		/*
1949		 * Do not trust the local APIC being empty at bootup.
1950		 */
1951		clear_local_APIC();
1952		/*
1953		 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
1954		 * local APIC to INT and NMI lines.
1955		 */
1956		apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1957				"enabling APIC mode.\n");
1958		imcr_pic_to_apic();
1959	}
1960#endif
1961}
1962
1963/**
1964 * disconnect_bsp_APIC - detach the APIC from the interrupt system
1965 * @virt_wire_setup:	indicates, whether virtual wire mode is selected
1966 *
1967 * Virtual wire mode is necessary to deliver legacy interrupts even when the
1968 * APIC is disabled.
1969 */
1970void disconnect_bsp_APIC(int virt_wire_setup)
1971{
1972	unsigned int value;
1973
1974#ifdef CONFIG_X86_32
1975	if (pic_mode) {
1976		/*
1977		 * Put the board back into PIC mode (has an effect only on
1978		 * certain older boards).  Note that APIC interrupts, including
1979		 * IPIs, won't work beyond this point!  The only exception are
1980		 * INIT IPIs.
1981		 */
1982		apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1983				"entering PIC mode.\n");
1984		imcr_apic_to_pic();
1985		return;
1986	}
1987#endif
1988
1989	/* Go back to Virtual Wire compatibility mode */
1990
1991	/* For the spurious interrupt use vector F, and enable it */
1992	value = apic_read(APIC_SPIV);
1993	value &= ~APIC_VECTOR_MASK;
1994	value |= APIC_SPIV_APIC_ENABLED;
1995	value |= 0xf;
1996	apic_write(APIC_SPIV, value);
1997
1998	if (!virt_wire_setup) {
1999		/*
2000		 * For LVT0 make it edge triggered, active high,
2001		 * external and enabled
2002		 */
2003		value = apic_read(APIC_LVT0);
2004		value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2005			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2006			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2007		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2008		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2009		apic_write(APIC_LVT0, value);
2010	} else {
2011		/* Disable LVT0 */
2012		apic_write(APIC_LVT0, APIC_LVT_MASKED);
2013	}
2014
2015	/*
2016	 * For LVT1 make it edge triggered, active high,
2017	 * nmi and enabled
2018	 */
2019	value = apic_read(APIC_LVT1);
2020	value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2021			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2022			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2023	value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2024	value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2025	apic_write(APIC_LVT1, value);
2026}
2027
2028/*
2029 * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2030 * contiguously, it equals to current allocated max logical CPU ID plus 1.
2031 * All allocated CPU ID should be in [0, nr_logical_cpuidi), so the maximum of
2032 * nr_logical_cpuids is nr_cpu_ids.
2033 *
2034 * NOTE: Reserve 0 for BSP.
2035 */
2036static int nr_logical_cpuids = 1;
2037
2038/*
2039 * Used to store mapping between logical CPU IDs and APIC IDs.
2040 */
2041static int cpuid_to_apicid[] = {
2042	[0 ... NR_CPUS - 1] = -1,
2043};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2044
2045/*
2046 * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2047 * and cpuid_to_apicid[] synchronized.
2048 */
2049static int allocate_logical_cpuid(int apicid)
2050{
2051	int i;
2052
2053	/*
2054	 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2055	 * check if the kernel has allocated a cpuid for it.
2056	 */
2057	for (i = 0; i < nr_logical_cpuids; i++) {
2058		if (cpuid_to_apicid[i] == apicid)
2059			return i;
2060	}
2061
2062	/* Allocate a new cpuid. */
2063	if (nr_logical_cpuids >= nr_cpu_ids) {
2064		WARN_ONCE(1, "Only %d processors supported."
2065			     "Processor %d/0x%x and the rest are ignored.\n",
2066			     nr_cpu_ids - 1, nr_logical_cpuids, apicid);
2067		return -1;
2068	}
2069
2070	cpuid_to_apicid[nr_logical_cpuids] = apicid;
2071	return nr_logical_cpuids++;
2072}
2073
2074int __generic_processor_info(int apicid, int version, bool enabled)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2075{
2076	int cpu, max = nr_cpu_ids;
2077	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2078				phys_cpu_present_map);
2079
2080	/*
2081	 * boot_cpu_physical_apicid is designed to have the apicid
2082	 * returned by read_apic_id(), i.e, the apicid of the
2083	 * currently booting-up processor. However, on some platforms,
2084	 * it is temporarily modified by the apicid reported as BSP
2085	 * through MP table. Concretely:
2086	 *
2087	 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2088	 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2089	 *
2090	 * This function is executed with the modified
2091	 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2092	 * parameter doesn't work to disable APs on kdump 2nd kernel.
2093	 *
2094	 * Since fixing handling of boot_cpu_physical_apicid requires
2095	 * another discussion and tests on each platform, we leave it
2096	 * for now and here we use read_apic_id() directly in this
2097	 * function, generic_processor_info().
2098	 */
2099	if (disabled_cpu_apicid != BAD_APICID &&
2100	    disabled_cpu_apicid != read_apic_id() &&
2101	    disabled_cpu_apicid == apicid) {
2102		int thiscpu = num_processors + disabled_cpus;
2103
2104		pr_warning("APIC: Disabling requested cpu."
2105			   " Processor %d/0x%x ignored.\n",
2106			   thiscpu, apicid);
2107
2108		disabled_cpus++;
2109		return -ENODEV;
2110	}
2111
2112	/*
2113	 * If boot cpu has not been detected yet, then only allow upto
2114	 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2115	 */
2116	if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2117	    apicid != boot_cpu_physical_apicid) {
2118		int thiscpu = max + disabled_cpus - 1;
2119
2120		pr_warning(
2121			"APIC: NR_CPUS/possible_cpus limit of %i almost"
2122			" reached. Keeping one slot for boot cpu."
2123			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2124
2125		disabled_cpus++;
2126		return -ENODEV;
2127	}
2128
2129	if (num_processors >= nr_cpu_ids) {
2130		int thiscpu = max + disabled_cpus;
2131
2132		if (enabled) {
2133			pr_warning("APIC: NR_CPUS/possible_cpus limit of %i "
2134				   "reached. Processor %d/0x%x ignored.\n",
2135				   max, thiscpu, apicid);
2136		}
2137
2138		disabled_cpus++;
2139		return -EINVAL;
2140	}
2141
2142	if (apicid == boot_cpu_physical_apicid) {
2143		/*
2144		 * x86_bios_cpu_apicid is required to have processors listed
2145		 * in same order as logical cpu numbers. Hence the first
2146		 * entry is BSP, and so on.
2147		 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2148		 * for BSP.
2149		 */
2150		cpu = 0;
2151
2152		/* Logical cpuid 0 is reserved for BSP. */
2153		cpuid_to_apicid[0] = apicid;
2154	} else {
2155		cpu = allocate_logical_cpuid(apicid);
2156		if (cpu < 0) {
2157			disabled_cpus++;
2158			return -EINVAL;
2159		}
2160	}
2161
2162	/*
2163	 * Validate version
2164	 */
2165	if (version == 0x0) {
2166		pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2167			   cpu, apicid);
2168		version = 0x10;
2169	}
2170
2171	if (version != boot_cpu_apic_version) {
2172		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2173			boot_cpu_apic_version, cpu, version);
2174	}
2175
2176	if (apicid > max_physical_apicid)
2177		max_physical_apicid = apicid;
2178
2179#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2180	early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2181	early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2182#endif
2183#ifdef CONFIG_X86_32
2184	early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2185		apic->x86_32_early_logical_apicid(cpu);
2186#endif
2187	set_cpu_possible(cpu, true);
2188
2189	if (enabled) {
2190		num_processors++;
2191		physid_set(apicid, phys_cpu_present_map);
2192		set_cpu_present(cpu, true);
2193	} else {
2194		disabled_cpus++;
 
2195	}
2196
 
2197	return cpu;
2198}
2199
2200int generic_processor_info(int apicid, int version)
2201{
2202	return __generic_processor_info(apicid, version, true);
2203}
2204
2205int hard_smp_processor_id(void)
2206{
2207	return read_apic_id();
2208}
2209
2210void default_init_apic_ldr(void)
 
2211{
2212	unsigned long val;
2213
2214	apic_write(APIC_DFR, APIC_DFR_VALUE);
2215	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
2216	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
2217	apic_write(APIC_LDR, val);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2218}
2219
2220int default_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
2221				   const struct cpumask *andmask,
2222				   unsigned int *apicid)
2223{
2224	unsigned int cpu;
2225
2226	for_each_cpu_and(cpu, cpumask, andmask) {
2227		if (cpumask_test_cpu(cpu, cpu_online_mask))
2228			break;
2229	}
2230
2231	if (likely(cpu < nr_cpu_ids)) {
2232		*apicid = per_cpu(x86_cpu_to_apicid, cpu);
2233		return 0;
2234	}
2235
2236	return -EINVAL;
2237}
2238
2239/*
2240 * Override the generic EOI implementation with an optimized version.
2241 * Only called during early boot when only one CPU is active and with
2242 * interrupts disabled, so we know this does not race with actual APIC driver
2243 * use.
2244 */
2245void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2246{
2247	struct apic **drv;
2248
2249	for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2250		/* Should happen once for each apic */
2251		WARN_ON((*drv)->eoi_write == eoi_write);
2252		(*drv)->native_eoi_write = (*drv)->eoi_write;
2253		(*drv)->eoi_write = eoi_write;
2254	}
2255}
 
2256
2257static void __init apic_bsp_up_setup(void)
2258{
2259#ifdef CONFIG_X86_64
2260	apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
2261#else
2262	/*
2263	 * Hack: In case of kdump, after a crash, kernel might be booting
2264	 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2265	 * might be zero if read from MP tables. Get it from LAPIC.
2266	 */
2267# ifdef CONFIG_CRASH_DUMP
2268	boot_cpu_physical_apicid = read_apic_id();
2269# endif
2270#endif
2271	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2272}
2273
2274/**
2275 * apic_bsp_setup - Setup function for local apic and io-apic
2276 * @upmode:		Force UP mode (for APIC_init_uniprocessor)
2277 *
2278 * Returns:
2279 * apic_id of BSP APIC
2280 */
2281int __init apic_bsp_setup(bool upmode)
2282{
2283	int id;
2284
2285	connect_bsp_APIC();
2286	if (upmode)
2287		apic_bsp_up_setup();
2288	setup_local_APIC();
2289
2290	if (x2apic_mode)
2291		id = apic_read(APIC_LDR);
2292	else
2293		id = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
2294
2295	enable_IO_APIC();
2296	end_local_APIC_setup();
2297	irq_remap_enable_fault_handling();
2298	setup_IO_APIC();
2299	/* Setup local timer */
2300	x86_init.timers.setup_percpu_clockev();
2301	return id;
2302}
2303
2304/*
2305 * This initializes the IO-APIC and APIC hardware if this is
2306 * a UP kernel.
2307 */
2308int __init APIC_init_uniprocessor(void)
2309{
2310	if (disable_apic) {
2311		pr_info("Apic disabled\n");
2312		return -1;
2313	}
2314#ifdef CONFIG_X86_64
2315	if (!boot_cpu_has(X86_FEATURE_APIC)) {
2316		disable_apic = 1;
2317		pr_info("Apic disabled by BIOS\n");
2318		return -1;
2319	}
2320#else
2321	if (!smp_found_config && !boot_cpu_has(X86_FEATURE_APIC))
2322		return -1;
2323
2324	/*
2325	 * Complain if the BIOS pretends there is one.
2326	 */
2327	if (!boot_cpu_has(X86_FEATURE_APIC) &&
2328	    APIC_INTEGRATED(boot_cpu_apic_version)) {
2329		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
2330			boot_cpu_physical_apicid);
2331		return -1;
2332	}
2333#endif
2334
2335	if (!smp_found_config)
2336		disable_ioapic_support();
2337
2338	default_setup_apic_routing();
2339	apic_bsp_setup(true);
2340	return 0;
2341}
2342
2343#ifdef CONFIG_UP_LATE_INIT
2344void __init up_late_init(void)
2345{
2346	APIC_init_uniprocessor();
 
 
 
 
2347}
2348#endif
2349
2350/*
2351 * Power management
2352 */
2353#ifdef CONFIG_PM
2354
2355static struct {
2356	/*
2357	 * 'active' is true if the local APIC was enabled by us and
2358	 * not the BIOS; this signifies that we are also responsible
2359	 * for disabling it before entering apm/acpi suspend
2360	 */
2361	int active;
2362	/* r/w apic fields */
2363	unsigned int apic_id;
2364	unsigned int apic_taskpri;
2365	unsigned int apic_ldr;
2366	unsigned int apic_dfr;
2367	unsigned int apic_spiv;
2368	unsigned int apic_lvtt;
2369	unsigned int apic_lvtpc;
2370	unsigned int apic_lvt0;
2371	unsigned int apic_lvt1;
2372	unsigned int apic_lvterr;
2373	unsigned int apic_tmict;
2374	unsigned int apic_tdcr;
2375	unsigned int apic_thmr;
2376	unsigned int apic_cmci;
2377} apic_pm_state;
2378
2379static int lapic_suspend(void)
2380{
2381	unsigned long flags;
2382	int maxlvt;
2383
2384	if (!apic_pm_state.active)
2385		return 0;
2386
2387	maxlvt = lapic_get_maxlvt();
2388
2389	apic_pm_state.apic_id = apic_read(APIC_ID);
2390	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2391	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2392	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2393	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2394	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2395	if (maxlvt >= 4)
2396		apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2397	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2398	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2399	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2400	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2401	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2402#ifdef CONFIG_X86_THERMAL_VECTOR
2403	if (maxlvt >= 5)
2404		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2405#endif
2406#ifdef CONFIG_X86_MCE_INTEL
2407	if (maxlvt >= 6)
2408		apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2409#endif
2410
2411	local_irq_save(flags);
 
 
 
 
 
 
 
2412	disable_local_APIC();
2413
2414	irq_remapping_disable();
2415
2416	local_irq_restore(flags);
2417	return 0;
2418}
2419
2420static void lapic_resume(void)
2421{
2422	unsigned int l, h;
2423	unsigned long flags;
2424	int maxlvt;
2425
2426	if (!apic_pm_state.active)
2427		return;
2428
2429	local_irq_save(flags);
2430
2431	/*
2432	 * IO-APIC and PIC have their own resume routines.
2433	 * We just mask them here to make sure the interrupt
2434	 * subsystem is completely quiet while we enable x2apic
2435	 * and interrupt-remapping.
2436	 */
2437	mask_ioapic_entries();
2438	legacy_pic->mask_all();
2439
2440	if (x2apic_mode) {
2441		__x2apic_enable();
2442	} else {
2443		/*
2444		 * Make sure the APICBASE points to the right address
2445		 *
2446		 * FIXME! This will be wrong if we ever support suspend on
2447		 * SMP! We'll need to do this as part of the CPU restore!
2448		 */
2449		if (boot_cpu_data.x86 >= 6) {
2450			rdmsr(MSR_IA32_APICBASE, l, h);
2451			l &= ~MSR_IA32_APICBASE_BASE;
2452			l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2453			wrmsr(MSR_IA32_APICBASE, l, h);
2454		}
2455	}
2456
2457	maxlvt = lapic_get_maxlvt();
2458	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2459	apic_write(APIC_ID, apic_pm_state.apic_id);
2460	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2461	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2462	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2463	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2464	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2465	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2466#ifdef CONFIG_X86_THERMAL_VECTOR
2467	if (maxlvt >= 5)
2468		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2469#endif
2470#ifdef CONFIG_X86_MCE_INTEL
2471	if (maxlvt >= 6)
2472		apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2473#endif
2474	if (maxlvt >= 4)
2475		apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2476	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2477	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2478	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2479	apic_write(APIC_ESR, 0);
2480	apic_read(APIC_ESR);
2481	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2482	apic_write(APIC_ESR, 0);
2483	apic_read(APIC_ESR);
2484
2485	irq_remapping_reenable(x2apic_mode);
2486
2487	local_irq_restore(flags);
2488}
2489
2490/*
2491 * This device has no shutdown method - fully functioning local APICs
2492 * are needed on every CPU up until machine_halt/restart/poweroff.
2493 */
2494
2495static struct syscore_ops lapic_syscore_ops = {
2496	.resume		= lapic_resume,
2497	.suspend	= lapic_suspend,
2498};
2499
2500static void apic_pm_activate(void)
2501{
2502	apic_pm_state.active = 1;
2503}
2504
2505static int __init init_lapic_sysfs(void)
2506{
2507	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2508	if (boot_cpu_has(X86_FEATURE_APIC))
2509		register_syscore_ops(&lapic_syscore_ops);
2510
2511	return 0;
2512}
2513
2514/* local apic needs to resume before other devices access its registers. */
2515core_initcall(init_lapic_sysfs);
2516
2517#else	/* CONFIG_PM */
2518
2519static void apic_pm_activate(void) { }
2520
2521#endif	/* CONFIG_PM */
2522
2523#ifdef CONFIG_X86_64
2524
2525static int multi_checked;
2526static int multi;
2527
2528static int set_multi(const struct dmi_system_id *d)
2529{
2530	if (multi)
2531		return 0;
2532	pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2533	multi = 1;
2534	return 0;
2535}
2536
2537static const struct dmi_system_id multi_dmi_table[] = {
2538	{
2539		.callback = set_multi,
2540		.ident = "IBM System Summit2",
2541		.matches = {
2542			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2543			DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2544		},
2545	},
2546	{}
2547};
2548
2549static void dmi_check_multi(void)
2550{
2551	if (multi_checked)
2552		return;
2553
2554	dmi_check_system(multi_dmi_table);
2555	multi_checked = 1;
2556}
2557
2558/*
2559 * apic_is_clustered_box() -- Check if we can expect good TSC
2560 *
2561 * Thus far, the major user of this is IBM's Summit2 series:
2562 * Clustered boxes may have unsynced TSC problems if they are
2563 * multi-chassis.
2564 * Use DMI to check them
2565 */
2566int apic_is_clustered_box(void)
2567{
2568	dmi_check_multi();
2569	return multi;
2570}
2571#endif
2572
2573/*
2574 * APIC command line parameters
2575 */
2576static int __init setup_disableapic(char *arg)
2577{
2578	disable_apic = 1;
2579	setup_clear_cpu_cap(X86_FEATURE_APIC);
2580	return 0;
2581}
2582early_param("disableapic", setup_disableapic);
2583
2584/* same as disableapic, for compatibility */
2585static int __init setup_nolapic(char *arg)
2586{
2587	return setup_disableapic(arg);
2588}
2589early_param("nolapic", setup_nolapic);
2590
2591static int __init parse_lapic_timer_c2_ok(char *arg)
2592{
2593	local_apic_timer_c2_ok = 1;
2594	return 0;
2595}
2596early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2597
2598static int __init parse_disable_apic_timer(char *arg)
2599{
2600	disable_apic_timer = 1;
2601	return 0;
2602}
2603early_param("noapictimer", parse_disable_apic_timer);
2604
2605static int __init parse_nolapic_timer(char *arg)
2606{
2607	disable_apic_timer = 1;
2608	return 0;
2609}
2610early_param("nolapic_timer", parse_nolapic_timer);
2611
2612static int __init apic_set_verbosity(char *arg)
2613{
2614	if (!arg)  {
2615#ifdef CONFIG_X86_64
2616		skip_ioapic_setup = 0;
 
 
2617		return 0;
2618#endif
2619		return -EINVAL;
2620	}
2621
2622	if (strcmp("debug", arg) == 0)
2623		apic_verbosity = APIC_DEBUG;
2624	else if (strcmp("verbose", arg) == 0)
2625		apic_verbosity = APIC_VERBOSE;
 
2626	else {
2627		pr_warning("APIC Verbosity level %s not recognised"
2628			" use apic=verbose or apic=debug\n", arg);
2629		return -EINVAL;
2630	}
 
2631
2632	return 0;
2633}
2634early_param("apic", apic_set_verbosity);
2635
2636static int __init lapic_insert_resource(void)
2637{
2638	if (!apic_phys)
2639		return -1;
2640
2641	/* Put local APIC into the resource map. */
2642	lapic_resource.start = apic_phys;
2643	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2644	insert_resource(&iomem_resource, &lapic_resource);
2645
2646	return 0;
2647}
2648
2649/*
2650 * need call insert after e820_reserve_resources()
2651 * that is using request_resource
2652 */
2653late_initcall(lapic_insert_resource);
2654
2655static int __init apic_set_disabled_cpu_apicid(char *arg)
2656{
2657	if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2658		return -EINVAL;
2659
2660	return 0;
2661}
2662early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2663
2664static int __init apic_set_extnmi(char *arg)
2665{
2666	if (!arg)
2667		return -EINVAL;
2668
2669	if (!strncmp("all", arg, 3))
2670		apic_extnmi = APIC_EXTNMI_ALL;
2671	else if (!strncmp("none", arg, 4))
2672		apic_extnmi = APIC_EXTNMI_NONE;
2673	else if (!strncmp("bsp", arg, 3))
2674		apic_extnmi = APIC_EXTNMI_BSP;
2675	else {
2676		pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2677		return -EINVAL;
2678	}
2679
2680	return 0;
2681}
2682early_param("apic_extnmi", apic_set_extnmi);