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   1// SPDX-License-Identifier: GPL-2.0
   2
   3#define pr_fmt(fmt)     "DMAR-IR: " fmt
   4
   5#include <linux/interrupt.h>
   6#include <linux/dmar.h>
   7#include <linux/spinlock.h>
   8#include <linux/slab.h>
   9#include <linux/jiffies.h>
  10#include <linux/hpet.h>
  11#include <linux/pci.h>
  12#include <linux/irq.h>
  13#include <linux/intel-iommu.h>
  14#include <linux/acpi.h>
  15#include <linux/irqdomain.h>
  16#include <linux/crash_dump.h>
  17#include <asm/io_apic.h>
  18#include <asm/smp.h>
  19#include <asm/cpu.h>
  20#include <asm/irq_remapping.h>
  21#include <asm/pci-direct.h>
  22#include <asm/msidef.h>
  23
  24#include "irq_remapping.h"
  25
  26enum irq_mode {
  27	IRQ_REMAPPING,
  28	IRQ_POSTING,
  29};
  30
  31struct ioapic_scope {
  32	struct intel_iommu *iommu;
  33	unsigned int id;
  34	unsigned int bus;	/* PCI bus number */
  35	unsigned int devfn;	/* PCI devfn number */
  36};
  37
  38struct hpet_scope {
  39	struct intel_iommu *iommu;
  40	u8 id;
  41	unsigned int bus;
  42	unsigned int devfn;
  43};
  44
  45struct irq_2_iommu {
  46	struct intel_iommu *iommu;
  47	u16 irte_index;
  48	u16 sub_handle;
  49	u8  irte_mask;
  50	enum irq_mode mode;
  51};
  52
  53struct intel_ir_data {
  54	struct irq_2_iommu			irq_2_iommu;
  55	struct irte				irte_entry;
  56	union {
  57		struct msi_msg			msi_entry;
  58	};
  59};
  60
  61#define IR_X2APIC_MODE(mode) (mode ? (1 << 11) : 0)
  62#define IRTE_DEST(dest) ((eim_mode) ? dest : dest << 8)
  63
  64static int __read_mostly eim_mode;
  65static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
  66static struct hpet_scope ir_hpet[MAX_HPET_TBS];
  67
  68/*
  69 * Lock ordering:
  70 * ->dmar_global_lock
  71 *	->irq_2_ir_lock
  72 *		->qi->q_lock
  73 *	->iommu->register_lock
  74 * Note:
  75 * intel_irq_remap_ops.{supported,prepare,enable,disable,reenable} are called
  76 * in single-threaded environment with interrupt disabled, so no need to tabke
  77 * the dmar_global_lock.
  78 */
  79DEFINE_RAW_SPINLOCK(irq_2_ir_lock);
  80static const struct irq_domain_ops intel_ir_domain_ops;
  81
  82static void iommu_disable_irq_remapping(struct intel_iommu *iommu);
  83static int __init parse_ioapics_under_ir(void);
  84
  85static bool ir_pre_enabled(struct intel_iommu *iommu)
  86{
  87	return (iommu->flags & VTD_FLAG_IRQ_REMAP_PRE_ENABLED);
  88}
  89
  90static void clear_ir_pre_enabled(struct intel_iommu *iommu)
  91{
  92	iommu->flags &= ~VTD_FLAG_IRQ_REMAP_PRE_ENABLED;
  93}
  94
  95static void init_ir_status(struct intel_iommu *iommu)
  96{
  97	u32 gsts;
  98
  99	gsts = readl(iommu->reg + DMAR_GSTS_REG);
 100	if (gsts & DMA_GSTS_IRES)
 101		iommu->flags |= VTD_FLAG_IRQ_REMAP_PRE_ENABLED;
 102}
 103
 104static int alloc_irte(struct intel_iommu *iommu,
 105		      struct irq_2_iommu *irq_iommu, u16 count)
 106{
 107	struct ir_table *table = iommu->ir_table;
 108	unsigned int mask = 0;
 109	unsigned long flags;
 110	int index;
 111
 112	if (!count || !irq_iommu)
 113		return -1;
 114
 115	if (count > 1) {
 116		count = __roundup_pow_of_two(count);
 117		mask = ilog2(count);
 118	}
 119
 120	if (mask > ecap_max_handle_mask(iommu->ecap)) {
 121		pr_err("Requested mask %x exceeds the max invalidation handle"
 122		       " mask value %Lx\n", mask,
 123		       ecap_max_handle_mask(iommu->ecap));
 124		return -1;
 125	}
 126
 127	raw_spin_lock_irqsave(&irq_2_ir_lock, flags);
 128	index = bitmap_find_free_region(table->bitmap,
 129					INTR_REMAP_TABLE_ENTRIES, mask);
 130	if (index < 0) {
 131		pr_warn("IR%d: can't allocate an IRTE\n", iommu->seq_id);
 132	} else {
 133		irq_iommu->iommu = iommu;
 134		irq_iommu->irte_index =  index;
 135		irq_iommu->sub_handle = 0;
 136		irq_iommu->irte_mask = mask;
 137		irq_iommu->mode = IRQ_REMAPPING;
 138	}
 139	raw_spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 140
 141	return index;
 142}
 143
 144static int qi_flush_iec(struct intel_iommu *iommu, int index, int mask)
 145{
 146	struct qi_desc desc;
 147
 148	desc.qw0 = QI_IEC_IIDEX(index) | QI_IEC_TYPE | QI_IEC_IM(mask)
 149		   | QI_IEC_SELECTIVE;
 150	desc.qw1 = 0;
 151	desc.qw2 = 0;
 152	desc.qw3 = 0;
 153
 154	return qi_submit_sync(&desc, iommu);
 155}
 156
 157static int modify_irte(struct irq_2_iommu *irq_iommu,
 158		       struct irte *irte_modified)
 159{
 160	struct intel_iommu *iommu;
 161	unsigned long flags;
 162	struct irte *irte;
 163	int rc, index;
 164
 165	if (!irq_iommu)
 166		return -1;
 167
 168	raw_spin_lock_irqsave(&irq_2_ir_lock, flags);
 169
 170	iommu = irq_iommu->iommu;
 171
 172	index = irq_iommu->irte_index + irq_iommu->sub_handle;
 173	irte = &iommu->ir_table->base[index];
 174
 175#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE)
 176	if ((irte->pst == 1) || (irte_modified->pst == 1)) {
 177		bool ret;
 178
 179		ret = cmpxchg_double(&irte->low, &irte->high,
 180				     irte->low, irte->high,
 181				     irte_modified->low, irte_modified->high);
 182		/*
 183		 * We use cmpxchg16 to atomically update the 128-bit IRTE,
 184		 * and it cannot be updated by the hardware or other processors
 185		 * behind us, so the return value of cmpxchg16 should be the
 186		 * same as the old value.
 187		 */
 188		WARN_ON(!ret);
 189	} else
 190#endif
 191	{
 192		set_64bit(&irte->low, irte_modified->low);
 193		set_64bit(&irte->high, irte_modified->high);
 194	}
 195	__iommu_flush_cache(iommu, irte, sizeof(*irte));
 196
 197	rc = qi_flush_iec(iommu, index, 0);
 198
 199	/* Update iommu mode according to the IRTE mode */
 200	irq_iommu->mode = irte->pst ? IRQ_POSTING : IRQ_REMAPPING;
 201	raw_spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 202
 203	return rc;
 204}
 205
 206static struct intel_iommu *map_hpet_to_ir(u8 hpet_id)
 207{
 208	int i;
 209
 210	for (i = 0; i < MAX_HPET_TBS; i++)
 211		if (ir_hpet[i].id == hpet_id && ir_hpet[i].iommu)
 212			return ir_hpet[i].iommu;
 213	return NULL;
 214}
 215
 216static struct intel_iommu *map_ioapic_to_ir(int apic)
 217{
 218	int i;
 219
 220	for (i = 0; i < MAX_IO_APICS; i++)
 221		if (ir_ioapic[i].id == apic && ir_ioapic[i].iommu)
 222			return ir_ioapic[i].iommu;
 223	return NULL;
 224}
 225
 226static struct intel_iommu *map_dev_to_ir(struct pci_dev *dev)
 227{
 228	struct dmar_drhd_unit *drhd;
 229
 230	drhd = dmar_find_matched_drhd_unit(dev);
 231	if (!drhd)
 232		return NULL;
 233
 234	return drhd->iommu;
 235}
 236
 237static int clear_entries(struct irq_2_iommu *irq_iommu)
 238{
 239	struct irte *start, *entry, *end;
 240	struct intel_iommu *iommu;
 241	int index;
 242
 243	if (irq_iommu->sub_handle)
 244		return 0;
 245
 246	iommu = irq_iommu->iommu;
 247	index = irq_iommu->irte_index;
 248
 249	start = iommu->ir_table->base + index;
 250	end = start + (1 << irq_iommu->irte_mask);
 251
 252	for (entry = start; entry < end; entry++) {
 253		set_64bit(&entry->low, 0);
 254		set_64bit(&entry->high, 0);
 255	}
 256	bitmap_release_region(iommu->ir_table->bitmap, index,
 257			      irq_iommu->irte_mask);
 258
 259	return qi_flush_iec(iommu, index, irq_iommu->irte_mask);
 260}
 261
 262/*
 263 * source validation type
 264 */
 265#define SVT_NO_VERIFY		0x0  /* no verification is required */
 266#define SVT_VERIFY_SID_SQ	0x1  /* verify using SID and SQ fields */
 267#define SVT_VERIFY_BUS		0x2  /* verify bus of request-id */
 268
 269/*
 270 * source-id qualifier
 271 */
 272#define SQ_ALL_16	0x0  /* verify all 16 bits of request-id */
 273#define SQ_13_IGNORE_1	0x1  /* verify most significant 13 bits, ignore
 274			      * the third least significant bit
 275			      */
 276#define SQ_13_IGNORE_2	0x2  /* verify most significant 13 bits, ignore
 277			      * the second and third least significant bits
 278			      */
 279#define SQ_13_IGNORE_3	0x3  /* verify most significant 13 bits, ignore
 280			      * the least three significant bits
 281			      */
 282
 283/*
 284 * set SVT, SQ and SID fields of irte to verify
 285 * source ids of interrupt requests
 286 */
 287static void set_irte_sid(struct irte *irte, unsigned int svt,
 288			 unsigned int sq, unsigned int sid)
 289{
 290	if (disable_sourceid_checking)
 291		svt = SVT_NO_VERIFY;
 292	irte->svt = svt;
 293	irte->sq = sq;
 294	irte->sid = sid;
 295}
 296
 297/*
 298 * Set an IRTE to match only the bus number. Interrupt requests that reference
 299 * this IRTE must have a requester-id whose bus number is between or equal
 300 * to the start_bus and end_bus arguments.
 301 */
 302static void set_irte_verify_bus(struct irte *irte, unsigned int start_bus,
 303				unsigned int end_bus)
 304{
 305	set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16,
 306		     (start_bus << 8) | end_bus);
 307}
 308
 309static int set_ioapic_sid(struct irte *irte, int apic)
 310{
 311	int i;
 312	u16 sid = 0;
 313
 314	if (!irte)
 315		return -1;
 316
 317	down_read(&dmar_global_lock);
 318	for (i = 0; i < MAX_IO_APICS; i++) {
 319		if (ir_ioapic[i].iommu && ir_ioapic[i].id == apic) {
 320			sid = (ir_ioapic[i].bus << 8) | ir_ioapic[i].devfn;
 321			break;
 322		}
 323	}
 324	up_read(&dmar_global_lock);
 325
 326	if (sid == 0) {
 327		pr_warn("Failed to set source-id of IOAPIC (%d)\n", apic);
 328		return -1;
 329	}
 330
 331	set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16, sid);
 332
 333	return 0;
 334}
 335
 336static int set_hpet_sid(struct irte *irte, u8 id)
 337{
 338	int i;
 339	u16 sid = 0;
 340
 341	if (!irte)
 342		return -1;
 343
 344	down_read(&dmar_global_lock);
 345	for (i = 0; i < MAX_HPET_TBS; i++) {
 346		if (ir_hpet[i].iommu && ir_hpet[i].id == id) {
 347			sid = (ir_hpet[i].bus << 8) | ir_hpet[i].devfn;
 348			break;
 349		}
 350	}
 351	up_read(&dmar_global_lock);
 352
 353	if (sid == 0) {
 354		pr_warn("Failed to set source-id of HPET block (%d)\n", id);
 355		return -1;
 356	}
 357
 358	/*
 359	 * Should really use SQ_ALL_16. Some platforms are broken.
 360	 * While we figure out the right quirks for these broken platforms, use
 361	 * SQ_13_IGNORE_3 for now.
 362	 */
 363	set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_13_IGNORE_3, sid);
 364
 365	return 0;
 366}
 367
 368struct set_msi_sid_data {
 369	struct pci_dev *pdev;
 370	u16 alias;
 371	int count;
 372	int busmatch_count;
 373};
 374
 375static int set_msi_sid_cb(struct pci_dev *pdev, u16 alias, void *opaque)
 376{
 377	struct set_msi_sid_data *data = opaque;
 378
 379	if (data->count == 0 || PCI_BUS_NUM(alias) == PCI_BUS_NUM(data->alias))
 380		data->busmatch_count++;
 381
 382	data->pdev = pdev;
 383	data->alias = alias;
 384	data->count++;
 385
 386	return 0;
 387}
 388
 389static int set_msi_sid(struct irte *irte, struct pci_dev *dev)
 390{
 391	struct set_msi_sid_data data;
 392
 393	if (!irte || !dev)
 394		return -1;
 395
 396	data.count = 0;
 397	data.busmatch_count = 0;
 398	pci_for_each_dma_alias(dev, set_msi_sid_cb, &data);
 399
 400	/*
 401	 * DMA alias provides us with a PCI device and alias.  The only case
 402	 * where the it will return an alias on a different bus than the
 403	 * device is the case of a PCIe-to-PCI bridge, where the alias is for
 404	 * the subordinate bus.  In this case we can only verify the bus.
 405	 *
 406	 * If there are multiple aliases, all with the same bus number,
 407	 * then all we can do is verify the bus. This is typical in NTB
 408	 * hardware which use proxy IDs where the device will generate traffic
 409	 * from multiple devfn numbers on the same bus.
 410	 *
 411	 * If the alias device is on a different bus than our source device
 412	 * then we have a topology based alias, use it.
 413	 *
 414	 * Otherwise, the alias is for a device DMA quirk and we cannot
 415	 * assume that MSI uses the same requester ID.  Therefore use the
 416	 * original device.
 417	 */
 418	if (PCI_BUS_NUM(data.alias) != data.pdev->bus->number)
 419		set_irte_verify_bus(irte, PCI_BUS_NUM(data.alias),
 420				    dev->bus->number);
 421	else if (data.count >= 2 && data.busmatch_count == data.count)
 422		set_irte_verify_bus(irte, dev->bus->number, dev->bus->number);
 423	else if (data.pdev->bus->number != dev->bus->number)
 424		set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16, data.alias);
 425	else
 426		set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16,
 427			     pci_dev_id(dev));
 428
 429	return 0;
 430}
 431
 432static int iommu_load_old_irte(struct intel_iommu *iommu)
 433{
 434	struct irte *old_ir_table;
 435	phys_addr_t irt_phys;
 436	unsigned int i;
 437	size_t size;
 438	u64 irta;
 439
 440	/* Check whether the old ir-table has the same size as ours */
 441	irta = dmar_readq(iommu->reg + DMAR_IRTA_REG);
 442	if ((irta & INTR_REMAP_TABLE_REG_SIZE_MASK)
 443	     != INTR_REMAP_TABLE_REG_SIZE)
 444		return -EINVAL;
 445
 446	irt_phys = irta & VTD_PAGE_MASK;
 447	size     = INTR_REMAP_TABLE_ENTRIES*sizeof(struct irte);
 448
 449	/* Map the old IR table */
 450	old_ir_table = memremap(irt_phys, size, MEMREMAP_WB);
 451	if (!old_ir_table)
 452		return -ENOMEM;
 453
 454	/* Copy data over */
 455	memcpy(iommu->ir_table->base, old_ir_table, size);
 456
 457	__iommu_flush_cache(iommu, iommu->ir_table->base, size);
 458
 459	/*
 460	 * Now check the table for used entries and mark those as
 461	 * allocated in the bitmap
 462	 */
 463	for (i = 0; i < INTR_REMAP_TABLE_ENTRIES; i++) {
 464		if (iommu->ir_table->base[i].present)
 465			bitmap_set(iommu->ir_table->bitmap, i, 1);
 466	}
 467
 468	memunmap(old_ir_table);
 469
 470	return 0;
 471}
 472
 473
 474static void iommu_set_irq_remapping(struct intel_iommu *iommu, int mode)
 475{
 476	unsigned long flags;
 477	u64 addr;
 478	u32 sts;
 479
 480	addr = virt_to_phys((void *)iommu->ir_table->base);
 481
 482	raw_spin_lock_irqsave(&iommu->register_lock, flags);
 483
 484	dmar_writeq(iommu->reg + DMAR_IRTA_REG,
 485		    (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
 486
 487	/* Set interrupt-remapping table pointer */
 488	writel(iommu->gcmd | DMA_GCMD_SIRTP, iommu->reg + DMAR_GCMD_REG);
 489
 490	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 491		      readl, (sts & DMA_GSTS_IRTPS), sts);
 492	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 493
 494	/*
 495	 * Global invalidation of interrupt entry cache to make sure the
 496	 * hardware uses the new irq remapping table.
 497	 */
 498	qi_global_iec(iommu);
 499}
 500
 501static void iommu_enable_irq_remapping(struct intel_iommu *iommu)
 502{
 503	unsigned long flags;
 504	u32 sts;
 505
 506	raw_spin_lock_irqsave(&iommu->register_lock, flags);
 507
 508	/* Enable interrupt-remapping */
 509	iommu->gcmd |= DMA_GCMD_IRE;
 510	iommu->gcmd &= ~DMA_GCMD_CFI;  /* Block compatibility-format MSIs */
 511	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 512
 513	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 514		      readl, (sts & DMA_GSTS_IRES), sts);
 515
 516	/*
 517	 * With CFI clear in the Global Command register, we should be
 518	 * protected from dangerous (i.e. compatibility) interrupts
 519	 * regardless of x2apic status.  Check just to be sure.
 520	 */
 521	if (sts & DMA_GSTS_CFIS)
 522		WARN(1, KERN_WARNING
 523			"Compatibility-format IRQs enabled despite intr remapping;\n"
 524			"you are vulnerable to IRQ injection.\n");
 525
 526	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 527}
 528
 529static int intel_setup_irq_remapping(struct intel_iommu *iommu)
 530{
 531	struct ir_table *ir_table;
 532	struct fwnode_handle *fn;
 533	unsigned long *bitmap;
 534	struct page *pages;
 535
 536	if (iommu->ir_table)
 537		return 0;
 538
 539	ir_table = kzalloc(sizeof(struct ir_table), GFP_KERNEL);
 540	if (!ir_table)
 541		return -ENOMEM;
 542
 543	pages = alloc_pages_node(iommu->node, GFP_KERNEL | __GFP_ZERO,
 544				 INTR_REMAP_PAGE_ORDER);
 545	if (!pages) {
 546		pr_err("IR%d: failed to allocate pages of order %d\n",
 547		       iommu->seq_id, INTR_REMAP_PAGE_ORDER);
 548		goto out_free_table;
 549	}
 550
 551	bitmap = bitmap_zalloc(INTR_REMAP_TABLE_ENTRIES, GFP_ATOMIC);
 552	if (bitmap == NULL) {
 553		pr_err("IR%d: failed to allocate bitmap\n", iommu->seq_id);
 554		goto out_free_pages;
 555	}
 556
 557	fn = irq_domain_alloc_named_id_fwnode("INTEL-IR", iommu->seq_id);
 558	if (!fn)
 559		goto out_free_bitmap;
 560
 561	iommu->ir_domain =
 562		irq_domain_create_hierarchy(arch_get_ir_parent_domain(),
 563					    0, INTR_REMAP_TABLE_ENTRIES,
 564					    fn, &intel_ir_domain_ops,
 565					    iommu);
 566	irq_domain_free_fwnode(fn);
 567	if (!iommu->ir_domain) {
 568		pr_err("IR%d: failed to allocate irqdomain\n", iommu->seq_id);
 569		goto out_free_bitmap;
 570	}
 571	iommu->ir_msi_domain =
 572		arch_create_remap_msi_irq_domain(iommu->ir_domain,
 573						 "INTEL-IR-MSI",
 574						 iommu->seq_id);
 575
 576	ir_table->base = page_address(pages);
 577	ir_table->bitmap = bitmap;
 578	iommu->ir_table = ir_table;
 579
 580	/*
 581	 * If the queued invalidation is already initialized,
 582	 * shouldn't disable it.
 583	 */
 584	if (!iommu->qi) {
 585		/*
 586		 * Clear previous faults.
 587		 */
 588		dmar_fault(-1, iommu);
 589		dmar_disable_qi(iommu);
 590
 591		if (dmar_enable_qi(iommu)) {
 592			pr_err("Failed to enable queued invalidation\n");
 593			goto out_free_bitmap;
 594		}
 595	}
 596
 597	init_ir_status(iommu);
 598
 599	if (ir_pre_enabled(iommu)) {
 600		if (!is_kdump_kernel()) {
 601			pr_warn("IRQ remapping was enabled on %s but we are not in kdump mode\n",
 602				iommu->name);
 603			clear_ir_pre_enabled(iommu);
 604			iommu_disable_irq_remapping(iommu);
 605		} else if (iommu_load_old_irte(iommu))
 606			pr_err("Failed to copy IR table for %s from previous kernel\n",
 607			       iommu->name);
 608		else
 609			pr_info("Copied IR table for %s from previous kernel\n",
 610				iommu->name);
 611	}
 612
 613	iommu_set_irq_remapping(iommu, eim_mode);
 614
 615	return 0;
 616
 617out_free_bitmap:
 618	bitmap_free(bitmap);
 619out_free_pages:
 620	__free_pages(pages, INTR_REMAP_PAGE_ORDER);
 621out_free_table:
 622	kfree(ir_table);
 623
 624	iommu->ir_table  = NULL;
 625
 626	return -ENOMEM;
 627}
 628
 629static void intel_teardown_irq_remapping(struct intel_iommu *iommu)
 630{
 631	if (iommu && iommu->ir_table) {
 632		if (iommu->ir_msi_domain) {
 633			irq_domain_remove(iommu->ir_msi_domain);
 634			iommu->ir_msi_domain = NULL;
 635		}
 636		if (iommu->ir_domain) {
 637			irq_domain_remove(iommu->ir_domain);
 638			iommu->ir_domain = NULL;
 639		}
 640		free_pages((unsigned long)iommu->ir_table->base,
 641			   INTR_REMAP_PAGE_ORDER);
 642		bitmap_free(iommu->ir_table->bitmap);
 643		kfree(iommu->ir_table);
 644		iommu->ir_table = NULL;
 645	}
 646}
 647
 648/*
 649 * Disable Interrupt Remapping.
 650 */
 651static void iommu_disable_irq_remapping(struct intel_iommu *iommu)
 652{
 653	unsigned long flags;
 654	u32 sts;
 655
 656	if (!ecap_ir_support(iommu->ecap))
 657		return;
 658
 659	/*
 660	 * global invalidation of interrupt entry cache before disabling
 661	 * interrupt-remapping.
 662	 */
 663	qi_global_iec(iommu);
 664
 665	raw_spin_lock_irqsave(&iommu->register_lock, flags);
 666
 667	sts = readl(iommu->reg + DMAR_GSTS_REG);
 668	if (!(sts & DMA_GSTS_IRES))
 669		goto end;
 670
 671	iommu->gcmd &= ~DMA_GCMD_IRE;
 672	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 673
 674	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 675		      readl, !(sts & DMA_GSTS_IRES), sts);
 676
 677end:
 678	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 679}
 680
 681static int __init dmar_x2apic_optout(void)
 682{
 683	struct acpi_table_dmar *dmar;
 684	dmar = (struct acpi_table_dmar *)dmar_tbl;
 685	if (!dmar || no_x2apic_optout)
 686		return 0;
 687	return dmar->flags & DMAR_X2APIC_OPT_OUT;
 688}
 689
 690static void __init intel_cleanup_irq_remapping(void)
 691{
 692	struct dmar_drhd_unit *drhd;
 693	struct intel_iommu *iommu;
 694
 695	for_each_iommu(iommu, drhd) {
 696		if (ecap_ir_support(iommu->ecap)) {
 697			iommu_disable_irq_remapping(iommu);
 698			intel_teardown_irq_remapping(iommu);
 699		}
 700	}
 701
 702	if (x2apic_supported())
 703		pr_warn("Failed to enable irq remapping. You are vulnerable to irq-injection attacks.\n");
 704}
 705
 706static int __init intel_prepare_irq_remapping(void)
 707{
 708	struct dmar_drhd_unit *drhd;
 709	struct intel_iommu *iommu;
 710	int eim = 0;
 711
 712	if (irq_remap_broken) {
 713		pr_warn("This system BIOS has enabled interrupt remapping\n"
 714			"on a chipset that contains an erratum making that\n"
 715			"feature unstable.  To maintain system stability\n"
 716			"interrupt remapping is being disabled.  Please\n"
 717			"contact your BIOS vendor for an update\n");
 718		add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
 719		return -ENODEV;
 720	}
 721
 722	if (dmar_table_init() < 0)
 723		return -ENODEV;
 724
 725	if (!dmar_ir_support())
 726		return -ENODEV;
 727
 728	if (parse_ioapics_under_ir()) {
 729		pr_info("Not enabling interrupt remapping\n");
 730		goto error;
 731	}
 732
 733	/* First make sure all IOMMUs support IRQ remapping */
 734	for_each_iommu(iommu, drhd)
 735		if (!ecap_ir_support(iommu->ecap))
 736			goto error;
 737
 738	/* Detect remapping mode: lapic or x2apic */
 739	if (x2apic_supported()) {
 740		eim = !dmar_x2apic_optout();
 741		if (!eim) {
 742			pr_info("x2apic is disabled because BIOS sets x2apic opt out bit.");
 743			pr_info("Use 'intremap=no_x2apic_optout' to override the BIOS setting.\n");
 744		}
 745	}
 746
 747	for_each_iommu(iommu, drhd) {
 748		if (eim && !ecap_eim_support(iommu->ecap)) {
 749			pr_info("%s does not support EIM\n", iommu->name);
 750			eim = 0;
 751		}
 752	}
 753
 754	eim_mode = eim;
 755	if (eim)
 756		pr_info("Queued invalidation will be enabled to support x2apic and Intr-remapping.\n");
 757
 758	/* Do the initializations early */
 759	for_each_iommu(iommu, drhd) {
 760		if (intel_setup_irq_remapping(iommu)) {
 761			pr_err("Failed to setup irq remapping for %s\n",
 762			       iommu->name);
 763			goto error;
 764		}
 765	}
 766
 767	return 0;
 768
 769error:
 770	intel_cleanup_irq_remapping();
 771	return -ENODEV;
 772}
 773
 774/*
 775 * Set Posted-Interrupts capability.
 776 */
 777static inline void set_irq_posting_cap(void)
 778{
 779	struct dmar_drhd_unit *drhd;
 780	struct intel_iommu *iommu;
 781
 782	if (!disable_irq_post) {
 783		/*
 784		 * If IRTE is in posted format, the 'pda' field goes across the
 785		 * 64-bit boundary, we need use cmpxchg16b to atomically update
 786		 * it. We only expose posted-interrupt when X86_FEATURE_CX16
 787		 * is supported. Actually, hardware platforms supporting PI
 788		 * should have X86_FEATURE_CX16 support, this has been confirmed
 789		 * with Intel hardware guys.
 790		 */
 791		if (boot_cpu_has(X86_FEATURE_CX16))
 792			intel_irq_remap_ops.capability |= 1 << IRQ_POSTING_CAP;
 793
 794		for_each_iommu(iommu, drhd)
 795			if (!cap_pi_support(iommu->cap)) {
 796				intel_irq_remap_ops.capability &=
 797						~(1 << IRQ_POSTING_CAP);
 798				break;
 799			}
 800	}
 801}
 802
 803static int __init intel_enable_irq_remapping(void)
 804{
 805	struct dmar_drhd_unit *drhd;
 806	struct intel_iommu *iommu;
 807	bool setup = false;
 808
 809	/*
 810	 * Setup Interrupt-remapping for all the DRHD's now.
 811	 */
 812	for_each_iommu(iommu, drhd) {
 813		if (!ir_pre_enabled(iommu))
 814			iommu_enable_irq_remapping(iommu);
 815		setup = true;
 816	}
 817
 818	if (!setup)
 819		goto error;
 820
 821	irq_remapping_enabled = 1;
 822
 823	set_irq_posting_cap();
 824
 825	pr_info("Enabled IRQ remapping in %s mode\n", eim_mode ? "x2apic" : "xapic");
 826
 827	return eim_mode ? IRQ_REMAP_X2APIC_MODE : IRQ_REMAP_XAPIC_MODE;
 828
 829error:
 830	intel_cleanup_irq_remapping();
 831	return -1;
 832}
 833
 834static int ir_parse_one_hpet_scope(struct acpi_dmar_device_scope *scope,
 835				   struct intel_iommu *iommu,
 836				   struct acpi_dmar_hardware_unit *drhd)
 837{
 838	struct acpi_dmar_pci_path *path;
 839	u8 bus;
 840	int count, free = -1;
 841
 842	bus = scope->bus;
 843	path = (struct acpi_dmar_pci_path *)(scope + 1);
 844	count = (scope->length - sizeof(struct acpi_dmar_device_scope))
 845		/ sizeof(struct acpi_dmar_pci_path);
 846
 847	while (--count > 0) {
 848		/*
 849		 * Access PCI directly due to the PCI
 850		 * subsystem isn't initialized yet.
 851		 */
 852		bus = read_pci_config_byte(bus, path->device, path->function,
 853					   PCI_SECONDARY_BUS);
 854		path++;
 855	}
 856
 857	for (count = 0; count < MAX_HPET_TBS; count++) {
 858		if (ir_hpet[count].iommu == iommu &&
 859		    ir_hpet[count].id == scope->enumeration_id)
 860			return 0;
 861		else if (ir_hpet[count].iommu == NULL && free == -1)
 862			free = count;
 863	}
 864	if (free == -1) {
 865		pr_warn("Exceeded Max HPET blocks\n");
 866		return -ENOSPC;
 867	}
 868
 869	ir_hpet[free].iommu = iommu;
 870	ir_hpet[free].id    = scope->enumeration_id;
 871	ir_hpet[free].bus   = bus;
 872	ir_hpet[free].devfn = PCI_DEVFN(path->device, path->function);
 873	pr_info("HPET id %d under DRHD base 0x%Lx\n",
 874		scope->enumeration_id, drhd->address);
 875
 876	return 0;
 877}
 878
 879static int ir_parse_one_ioapic_scope(struct acpi_dmar_device_scope *scope,
 880				     struct intel_iommu *iommu,
 881				     struct acpi_dmar_hardware_unit *drhd)
 882{
 883	struct acpi_dmar_pci_path *path;
 884	u8 bus;
 885	int count, free = -1;
 886
 887	bus = scope->bus;
 888	path = (struct acpi_dmar_pci_path *)(scope + 1);
 889	count = (scope->length - sizeof(struct acpi_dmar_device_scope))
 890		/ sizeof(struct acpi_dmar_pci_path);
 891
 892	while (--count > 0) {
 893		/*
 894		 * Access PCI directly due to the PCI
 895		 * subsystem isn't initialized yet.
 896		 */
 897		bus = read_pci_config_byte(bus, path->device, path->function,
 898					   PCI_SECONDARY_BUS);
 899		path++;
 900	}
 901
 902	for (count = 0; count < MAX_IO_APICS; count++) {
 903		if (ir_ioapic[count].iommu == iommu &&
 904		    ir_ioapic[count].id == scope->enumeration_id)
 905			return 0;
 906		else if (ir_ioapic[count].iommu == NULL && free == -1)
 907			free = count;
 908	}
 909	if (free == -1) {
 910		pr_warn("Exceeded Max IO APICS\n");
 911		return -ENOSPC;
 912	}
 913
 914	ir_ioapic[free].bus   = bus;
 915	ir_ioapic[free].devfn = PCI_DEVFN(path->device, path->function);
 916	ir_ioapic[free].iommu = iommu;
 917	ir_ioapic[free].id    = scope->enumeration_id;
 918	pr_info("IOAPIC id %d under DRHD base  0x%Lx IOMMU %d\n",
 919		scope->enumeration_id, drhd->address, iommu->seq_id);
 920
 921	return 0;
 922}
 923
 924static int ir_parse_ioapic_hpet_scope(struct acpi_dmar_header *header,
 925				      struct intel_iommu *iommu)
 926{
 927	int ret = 0;
 928	struct acpi_dmar_hardware_unit *drhd;
 929	struct acpi_dmar_device_scope *scope;
 930	void *start, *end;
 931
 932	drhd = (struct acpi_dmar_hardware_unit *)header;
 933	start = (void *)(drhd + 1);
 934	end = ((void *)drhd) + header->length;
 935
 936	while (start < end && ret == 0) {
 937		scope = start;
 938		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_IOAPIC)
 939			ret = ir_parse_one_ioapic_scope(scope, iommu, drhd);
 940		else if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_HPET)
 941			ret = ir_parse_one_hpet_scope(scope, iommu, drhd);
 942		start += scope->length;
 943	}
 944
 945	return ret;
 946}
 947
 948static void ir_remove_ioapic_hpet_scope(struct intel_iommu *iommu)
 949{
 950	int i;
 951
 952	for (i = 0; i < MAX_HPET_TBS; i++)
 953		if (ir_hpet[i].iommu == iommu)
 954			ir_hpet[i].iommu = NULL;
 955
 956	for (i = 0; i < MAX_IO_APICS; i++)
 957		if (ir_ioapic[i].iommu == iommu)
 958			ir_ioapic[i].iommu = NULL;
 959}
 960
 961/*
 962 * Finds the assocaition between IOAPIC's and its Interrupt-remapping
 963 * hardware unit.
 964 */
 965static int __init parse_ioapics_under_ir(void)
 966{
 967	struct dmar_drhd_unit *drhd;
 968	struct intel_iommu *iommu;
 969	bool ir_supported = false;
 970	int ioapic_idx;
 971
 972	for_each_iommu(iommu, drhd) {
 973		int ret;
 974
 975		if (!ecap_ir_support(iommu->ecap))
 976			continue;
 977
 978		ret = ir_parse_ioapic_hpet_scope(drhd->hdr, iommu);
 979		if (ret)
 980			return ret;
 981
 982		ir_supported = true;
 983	}
 984
 985	if (!ir_supported)
 986		return -ENODEV;
 987
 988	for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++) {
 989		int ioapic_id = mpc_ioapic_id(ioapic_idx);
 990		if (!map_ioapic_to_ir(ioapic_id)) {
 991			pr_err(FW_BUG "ioapic %d has no mapping iommu, "
 992			       "interrupt remapping will be disabled\n",
 993			       ioapic_id);
 994			return -1;
 995		}
 996	}
 997
 998	return 0;
 999}
1000
1001static int __init ir_dev_scope_init(void)
1002{
1003	int ret;
1004
1005	if (!irq_remapping_enabled)
1006		return 0;
1007
1008	down_write(&dmar_global_lock);
1009	ret = dmar_dev_scope_init();
1010	up_write(&dmar_global_lock);
1011
1012	return ret;
1013}
1014rootfs_initcall(ir_dev_scope_init);
1015
1016static void disable_irq_remapping(void)
1017{
1018	struct dmar_drhd_unit *drhd;
1019	struct intel_iommu *iommu = NULL;
1020
1021	/*
1022	 * Disable Interrupt-remapping for all the DRHD's now.
1023	 */
1024	for_each_iommu(iommu, drhd) {
1025		if (!ecap_ir_support(iommu->ecap))
1026			continue;
1027
1028		iommu_disable_irq_remapping(iommu);
1029	}
1030
1031	/*
1032	 * Clear Posted-Interrupts capability.
1033	 */
1034	if (!disable_irq_post)
1035		intel_irq_remap_ops.capability &= ~(1 << IRQ_POSTING_CAP);
1036}
1037
1038static int reenable_irq_remapping(int eim)
1039{
1040	struct dmar_drhd_unit *drhd;
1041	bool setup = false;
1042	struct intel_iommu *iommu = NULL;
1043
1044	for_each_iommu(iommu, drhd)
1045		if (iommu->qi)
1046			dmar_reenable_qi(iommu);
1047
1048	/*
1049	 * Setup Interrupt-remapping for all the DRHD's now.
1050	 */
1051	for_each_iommu(iommu, drhd) {
1052		if (!ecap_ir_support(iommu->ecap))
1053			continue;
1054
1055		/* Set up interrupt remapping for iommu.*/
1056		iommu_set_irq_remapping(iommu, eim);
1057		iommu_enable_irq_remapping(iommu);
1058		setup = true;
1059	}
1060
1061	if (!setup)
1062		goto error;
1063
1064	set_irq_posting_cap();
1065
1066	return 0;
1067
1068error:
1069	/*
1070	 * handle error condition gracefully here!
1071	 */
1072	return -1;
1073}
1074
1075static void prepare_irte(struct irte *irte, int vector, unsigned int dest)
1076{
1077	memset(irte, 0, sizeof(*irte));
1078
1079	irte->present = 1;
1080	irte->dst_mode = apic->irq_dest_mode;
1081	/*
1082	 * Trigger mode in the IRTE will always be edge, and for IO-APIC, the
1083	 * actual level or edge trigger will be setup in the IO-APIC
1084	 * RTE. This will help simplify level triggered irq migration.
1085	 * For more details, see the comments (in io_apic.c) explainig IO-APIC
1086	 * irq migration in the presence of interrupt-remapping.
1087	*/
1088	irte->trigger_mode = 0;
1089	irte->dlvry_mode = apic->irq_delivery_mode;
1090	irte->vector = vector;
1091	irte->dest_id = IRTE_DEST(dest);
1092	irte->redir_hint = 1;
1093}
1094
1095static struct irq_domain *intel_get_ir_irq_domain(struct irq_alloc_info *info)
1096{
1097	struct intel_iommu *iommu = NULL;
1098
1099	if (!info)
1100		return NULL;
1101
1102	switch (info->type) {
1103	case X86_IRQ_ALLOC_TYPE_IOAPIC:
1104		iommu = map_ioapic_to_ir(info->ioapic_id);
1105		break;
1106	case X86_IRQ_ALLOC_TYPE_HPET:
1107		iommu = map_hpet_to_ir(info->hpet_id);
1108		break;
1109	case X86_IRQ_ALLOC_TYPE_MSI:
1110	case X86_IRQ_ALLOC_TYPE_MSIX:
1111		iommu = map_dev_to_ir(info->msi_dev);
1112		break;
1113	default:
1114		BUG_ON(1);
1115		break;
1116	}
1117
1118	return iommu ? iommu->ir_domain : NULL;
1119}
1120
1121static struct irq_domain *intel_get_irq_domain(struct irq_alloc_info *info)
1122{
1123	struct intel_iommu *iommu;
1124
1125	if (!info)
1126		return NULL;
1127
1128	switch (info->type) {
1129	case X86_IRQ_ALLOC_TYPE_MSI:
1130	case X86_IRQ_ALLOC_TYPE_MSIX:
1131		iommu = map_dev_to_ir(info->msi_dev);
1132		if (iommu)
1133			return iommu->ir_msi_domain;
1134		break;
1135	default:
1136		break;
1137	}
1138
1139	return NULL;
1140}
1141
1142struct irq_remap_ops intel_irq_remap_ops = {
1143	.prepare		= intel_prepare_irq_remapping,
1144	.enable			= intel_enable_irq_remapping,
1145	.disable		= disable_irq_remapping,
1146	.reenable		= reenable_irq_remapping,
1147	.enable_faulting	= enable_drhd_fault_handling,
1148	.get_ir_irq_domain	= intel_get_ir_irq_domain,
1149	.get_irq_domain		= intel_get_irq_domain,
1150};
1151
1152static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force)
1153{
1154	struct intel_ir_data *ir_data = irqd->chip_data;
1155	struct irte *irte = &ir_data->irte_entry;
1156	struct irq_cfg *cfg = irqd_cfg(irqd);
1157
1158	/*
1159	 * Atomically updates the IRTE with the new destination, vector
1160	 * and flushes the interrupt entry cache.
1161	 */
1162	irte->vector = cfg->vector;
1163	irte->dest_id = IRTE_DEST(cfg->dest_apicid);
1164
1165	/* Update the hardware only if the interrupt is in remapped mode. */
1166	if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING)
1167		modify_irte(&ir_data->irq_2_iommu, irte);
1168}
1169
1170/*
1171 * Migrate the IO-APIC irq in the presence of intr-remapping.
1172 *
1173 * For both level and edge triggered, irq migration is a simple atomic
1174 * update(of vector and cpu destination) of IRTE and flush the hardware cache.
1175 *
1176 * For level triggered, we eliminate the io-apic RTE modification (with the
1177 * updated vector information), by using a virtual vector (io-apic pin number).
1178 * Real vector that is used for interrupting cpu will be coming from
1179 * the interrupt-remapping table entry.
1180 *
1181 * As the migration is a simple atomic update of IRTE, the same mechanism
1182 * is used to migrate MSI irq's in the presence of interrupt-remapping.
1183 */
1184static int
1185intel_ir_set_affinity(struct irq_data *data, const struct cpumask *mask,
1186		      bool force)
1187{
1188	struct irq_data *parent = data->parent_data;
1189	struct irq_cfg *cfg = irqd_cfg(data);
1190	int ret;
1191
1192	ret = parent->chip->irq_set_affinity(parent, mask, force);
1193	if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
1194		return ret;
1195
1196	intel_ir_reconfigure_irte(data, false);
1197	/*
1198	 * After this point, all the interrupts will start arriving
1199	 * at the new destination. So, time to cleanup the previous
1200	 * vector allocation.
1201	 */
1202	send_cleanup_vector(cfg);
1203
1204	return IRQ_SET_MASK_OK_DONE;
1205}
1206
1207static void intel_ir_compose_msi_msg(struct irq_data *irq_data,
1208				     struct msi_msg *msg)
1209{
1210	struct intel_ir_data *ir_data = irq_data->chip_data;
1211
1212	*msg = ir_data->msi_entry;
1213}
1214
1215static int intel_ir_set_vcpu_affinity(struct irq_data *data, void *info)
1216{
1217	struct intel_ir_data *ir_data = data->chip_data;
1218	struct vcpu_data *vcpu_pi_info = info;
1219
1220	/* stop posting interrupts, back to remapping mode */
1221	if (!vcpu_pi_info) {
1222		modify_irte(&ir_data->irq_2_iommu, &ir_data->irte_entry);
1223	} else {
1224		struct irte irte_pi;
1225
1226		/*
1227		 * We are not caching the posted interrupt entry. We
1228		 * copy the data from the remapped entry and modify
1229		 * the fields which are relevant for posted mode. The
1230		 * cached remapped entry is used for switching back to
1231		 * remapped mode.
1232		 */
1233		memset(&irte_pi, 0, sizeof(irte_pi));
1234		dmar_copy_shared_irte(&irte_pi, &ir_data->irte_entry);
1235
1236		/* Update the posted mode fields */
1237		irte_pi.p_pst = 1;
1238		irte_pi.p_urgent = 0;
1239		irte_pi.p_vector = vcpu_pi_info->vector;
1240		irte_pi.pda_l = (vcpu_pi_info->pi_desc_addr >>
1241				(32 - PDA_LOW_BIT)) & ~(-1UL << PDA_LOW_BIT);
1242		irte_pi.pda_h = (vcpu_pi_info->pi_desc_addr >> 32) &
1243				~(-1UL << PDA_HIGH_BIT);
1244
1245		modify_irte(&ir_data->irq_2_iommu, &irte_pi);
1246	}
1247
1248	return 0;
1249}
1250
1251static struct irq_chip intel_ir_chip = {
1252	.name			= "INTEL-IR",
1253	.irq_ack		= apic_ack_irq,
1254	.irq_set_affinity	= intel_ir_set_affinity,
1255	.irq_compose_msi_msg	= intel_ir_compose_msi_msg,
1256	.irq_set_vcpu_affinity	= intel_ir_set_vcpu_affinity,
1257};
1258
1259static void intel_irq_remapping_prepare_irte(struct intel_ir_data *data,
1260					     struct irq_cfg *irq_cfg,
1261					     struct irq_alloc_info *info,
1262					     int index, int sub_handle)
1263{
1264	struct IR_IO_APIC_route_entry *entry;
1265	struct irte *irte = &data->irte_entry;
1266	struct msi_msg *msg = &data->msi_entry;
1267
1268	prepare_irte(irte, irq_cfg->vector, irq_cfg->dest_apicid);
1269	switch (info->type) {
1270	case X86_IRQ_ALLOC_TYPE_IOAPIC:
1271		/* Set source-id of interrupt request */
1272		set_ioapic_sid(irte, info->ioapic_id);
1273		apic_printk(APIC_VERBOSE, KERN_DEBUG "IOAPIC[%d]: Set IRTE entry (P:%d FPD:%d Dst_Mode:%d Redir_hint:%d Trig_Mode:%d Dlvry_Mode:%X Avail:%X Vector:%02X Dest:%08X SID:%04X SQ:%X SVT:%X)\n",
1274			info->ioapic_id, irte->present, irte->fpd,
1275			irte->dst_mode, irte->redir_hint,
1276			irte->trigger_mode, irte->dlvry_mode,
1277			irte->avail, irte->vector, irte->dest_id,
1278			irte->sid, irte->sq, irte->svt);
1279
1280		entry = (struct IR_IO_APIC_route_entry *)info->ioapic_entry;
1281		info->ioapic_entry = NULL;
1282		memset(entry, 0, sizeof(*entry));
1283		entry->index2	= (index >> 15) & 0x1;
1284		entry->zero	= 0;
1285		entry->format	= 1;
1286		entry->index	= (index & 0x7fff);
1287		/*
1288		 * IO-APIC RTE will be configured with virtual vector.
1289		 * irq handler will do the explicit EOI to the io-apic.
1290		 */
1291		entry->vector	= info->ioapic_pin;
1292		entry->mask	= 0;			/* enable IRQ */
1293		entry->trigger	= info->ioapic_trigger;
1294		entry->polarity	= info->ioapic_polarity;
1295		if (info->ioapic_trigger)
1296			entry->mask = 1; /* Mask level triggered irqs. */
1297		break;
1298
1299	case X86_IRQ_ALLOC_TYPE_HPET:
1300	case X86_IRQ_ALLOC_TYPE_MSI:
1301	case X86_IRQ_ALLOC_TYPE_MSIX:
1302		if (info->type == X86_IRQ_ALLOC_TYPE_HPET)
1303			set_hpet_sid(irte, info->hpet_id);
1304		else
1305			set_msi_sid(irte, info->msi_dev);
1306
1307		msg->address_hi = MSI_ADDR_BASE_HI;
1308		msg->data = sub_handle;
1309		msg->address_lo = MSI_ADDR_BASE_LO | MSI_ADDR_IR_EXT_INT |
1310				  MSI_ADDR_IR_SHV |
1311				  MSI_ADDR_IR_INDEX1(index) |
1312				  MSI_ADDR_IR_INDEX2(index);
1313		break;
1314
1315	default:
1316		BUG_ON(1);
1317		break;
1318	}
1319}
1320
1321static void intel_free_irq_resources(struct irq_domain *domain,
1322				     unsigned int virq, unsigned int nr_irqs)
1323{
1324	struct irq_data *irq_data;
1325	struct intel_ir_data *data;
1326	struct irq_2_iommu *irq_iommu;
1327	unsigned long flags;
1328	int i;
1329	for (i = 0; i < nr_irqs; i++) {
1330		irq_data = irq_domain_get_irq_data(domain, virq  + i);
1331		if (irq_data && irq_data->chip_data) {
1332			data = irq_data->chip_data;
1333			irq_iommu = &data->irq_2_iommu;
1334			raw_spin_lock_irqsave(&irq_2_ir_lock, flags);
1335			clear_entries(irq_iommu);
1336			raw_spin_unlock_irqrestore(&irq_2_ir_lock, flags);
1337			irq_domain_reset_irq_data(irq_data);
1338			kfree(data);
1339		}
1340	}
1341}
1342
1343static int intel_irq_remapping_alloc(struct irq_domain *domain,
1344				     unsigned int virq, unsigned int nr_irqs,
1345				     void *arg)
1346{
1347	struct intel_iommu *iommu = domain->host_data;
1348	struct irq_alloc_info *info = arg;
1349	struct intel_ir_data *data, *ird;
1350	struct irq_data *irq_data;
1351	struct irq_cfg *irq_cfg;
1352	int i, ret, index;
1353
1354	if (!info || !iommu)
1355		return -EINVAL;
1356	if (nr_irqs > 1 && info->type != X86_IRQ_ALLOC_TYPE_MSI &&
1357	    info->type != X86_IRQ_ALLOC_TYPE_MSIX)
1358		return -EINVAL;
1359
1360	/*
1361	 * With IRQ remapping enabled, don't need contiguous CPU vectors
1362	 * to support multiple MSI interrupts.
1363	 */
1364	if (info->type == X86_IRQ_ALLOC_TYPE_MSI)
1365		info->flags &= ~X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;
1366
1367	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
1368	if (ret < 0)
1369		return ret;
1370
1371	ret = -ENOMEM;
1372	data = kzalloc(sizeof(*data), GFP_KERNEL);
1373	if (!data)
1374		goto out_free_parent;
1375
1376	down_read(&dmar_global_lock);
1377	index = alloc_irte(iommu, &data->irq_2_iommu, nr_irqs);
1378	up_read(&dmar_global_lock);
1379	if (index < 0) {
1380		pr_warn("Failed to allocate IRTE\n");
1381		kfree(data);
1382		goto out_free_parent;
1383	}
1384
1385	for (i = 0; i < nr_irqs; i++) {
1386		irq_data = irq_domain_get_irq_data(domain, virq + i);
1387		irq_cfg = irqd_cfg(irq_data);
1388		if (!irq_data || !irq_cfg) {
1389			ret = -EINVAL;
1390			goto out_free_data;
1391		}
1392
1393		if (i > 0) {
1394			ird = kzalloc(sizeof(*ird), GFP_KERNEL);
1395			if (!ird)
1396				goto out_free_data;
1397			/* Initialize the common data */
1398			ird->irq_2_iommu = data->irq_2_iommu;
1399			ird->irq_2_iommu.sub_handle = i;
1400		} else {
1401			ird = data;
1402		}
1403
1404		irq_data->hwirq = (index << 16) + i;
1405		irq_data->chip_data = ird;
1406		irq_data->chip = &intel_ir_chip;
1407		intel_irq_remapping_prepare_irte(ird, irq_cfg, info, index, i);
1408		irq_set_status_flags(virq + i, IRQ_MOVE_PCNTXT);
1409	}
1410	return 0;
1411
1412out_free_data:
1413	intel_free_irq_resources(domain, virq, i);
1414out_free_parent:
1415	irq_domain_free_irqs_common(domain, virq, nr_irqs);
1416	return ret;
1417}
1418
1419static void intel_irq_remapping_free(struct irq_domain *domain,
1420				     unsigned int virq, unsigned int nr_irqs)
1421{
1422	intel_free_irq_resources(domain, virq, nr_irqs);
1423	irq_domain_free_irqs_common(domain, virq, nr_irqs);
1424}
1425
1426static int intel_irq_remapping_activate(struct irq_domain *domain,
1427					struct irq_data *irq_data, bool reserve)
1428{
1429	intel_ir_reconfigure_irte(irq_data, true);
1430	return 0;
1431}
1432
1433static void intel_irq_remapping_deactivate(struct irq_domain *domain,
1434					   struct irq_data *irq_data)
1435{
1436	struct intel_ir_data *data = irq_data->chip_data;
1437	struct irte entry;
1438
1439	memset(&entry, 0, sizeof(entry));
1440	modify_irte(&data->irq_2_iommu, &entry);
1441}
1442
1443static const struct irq_domain_ops intel_ir_domain_ops = {
1444	.alloc = intel_irq_remapping_alloc,
1445	.free = intel_irq_remapping_free,
1446	.activate = intel_irq_remapping_activate,
1447	.deactivate = intel_irq_remapping_deactivate,
1448};
1449
1450/*
1451 * Support of Interrupt Remapping Unit Hotplug
1452 */
1453static int dmar_ir_add(struct dmar_drhd_unit *dmaru, struct intel_iommu *iommu)
1454{
1455	int ret;
1456	int eim = x2apic_enabled();
1457
1458	if (eim && !ecap_eim_support(iommu->ecap)) {
1459		pr_info("DRHD %Lx: EIM not supported by DRHD, ecap %Lx\n",
1460			iommu->reg_phys, iommu->ecap);
1461		return -ENODEV;
1462	}
1463
1464	if (ir_parse_ioapic_hpet_scope(dmaru->hdr, iommu)) {
1465		pr_warn("DRHD %Lx: failed to parse managed IOAPIC/HPET\n",
1466			iommu->reg_phys);
1467		return -ENODEV;
1468	}
1469
1470	/* TODO: check all IOAPICs are covered by IOMMU */
1471
1472	/* Setup Interrupt-remapping now. */
1473	ret = intel_setup_irq_remapping(iommu);
1474	if (ret) {
1475		pr_err("Failed to setup irq remapping for %s\n",
1476		       iommu->name);
1477		intel_teardown_irq_remapping(iommu);
1478		ir_remove_ioapic_hpet_scope(iommu);
1479	} else {
1480		iommu_enable_irq_remapping(iommu);
1481	}
1482
1483	return ret;
1484}
1485
1486int dmar_ir_hotplug(struct dmar_drhd_unit *dmaru, bool insert)
1487{
1488	int ret = 0;
1489	struct intel_iommu *iommu = dmaru->iommu;
1490
1491	if (!irq_remapping_enabled)
1492		return 0;
1493	if (iommu == NULL)
1494		return -EINVAL;
1495	if (!ecap_ir_support(iommu->ecap))
1496		return 0;
1497	if (irq_remapping_cap(IRQ_POSTING_CAP) &&
1498	    !cap_pi_support(iommu->cap))
1499		return -EBUSY;
1500
1501	if (insert) {
1502		if (!iommu->ir_table)
1503			ret = dmar_ir_add(dmaru, iommu);
1504	} else {
1505		if (iommu->ir_table) {
1506			if (!bitmap_empty(iommu->ir_table->bitmap,
1507					  INTR_REMAP_TABLE_ENTRIES)) {
1508				ret = -EBUSY;
1509			} else {
1510				iommu_disable_irq_remapping(iommu);
1511				intel_teardown_irq_remapping(iommu);
1512				ir_remove_ioapic_hpet_scope(iommu);
1513			}
1514		}
1515	}
1516
1517	return ret;
1518}