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