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   1/*
   2 * Copyright (c) 2006, Intel Corporation.
   3 *
   4 * This program is free software; you can redistribute it and/or modify it
   5 * under the terms and conditions of the GNU General Public License,
   6 * version 2, as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope it will be useful, but WITHOUT
   9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11 * more details.
  12 *
  13 * You should have received a copy of the GNU General Public License along with
  14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15 * Place - Suite 330, Boston, MA 02111-1307 USA.
  16 *
  17 * Copyright (C) 2006-2008 Intel Corporation
  18 * Author: Ashok Raj <ashok.raj@intel.com>
  19 * Author: Shaohua Li <shaohua.li@intel.com>
  20 * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  21 * Author: Fenghua Yu <fenghua.yu@intel.com>
  22 */
  23
  24#include <linux/init.h>
  25#include <linux/bitmap.h>
  26#include <linux/debugfs.h>
  27#include <linux/slab.h>
  28#include <linux/irq.h>
  29#include <linux/interrupt.h>
  30#include <linux/spinlock.h>
  31#include <linux/pci.h>
  32#include <linux/dmar.h>
  33#include <linux/dma-mapping.h>
  34#include <linux/mempool.h>
  35#include <linux/timer.h>
  36#include <linux/iova.h>
  37#include <linux/iommu.h>
  38#include <linux/intel-iommu.h>
  39#include <linux/syscore_ops.h>
  40#include <linux/tboot.h>
  41#include <linux/dmi.h>
  42#include <linux/pci-ats.h>
  43#include <asm/cacheflush.h>
  44#include <asm/iommu.h>
  45
  46#define ROOT_SIZE		VTD_PAGE_SIZE
  47#define CONTEXT_SIZE		VTD_PAGE_SIZE
  48
  49#define IS_BRIDGE_HOST_DEVICE(pdev) \
  50			    ((pdev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
  51#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
  52#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
  53#define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
  54
  55#define IOAPIC_RANGE_START	(0xfee00000)
  56#define IOAPIC_RANGE_END	(0xfeefffff)
  57#define IOVA_START_ADDR		(0x1000)
  58
  59#define DEFAULT_DOMAIN_ADDRESS_WIDTH 48
  60
  61#define MAX_AGAW_WIDTH 64
  62
  63#define __DOMAIN_MAX_PFN(gaw)  ((((uint64_t)1) << (gaw-VTD_PAGE_SHIFT)) - 1)
  64#define __DOMAIN_MAX_ADDR(gaw) ((((uint64_t)1) << gaw) - 1)
  65
  66/* We limit DOMAIN_MAX_PFN to fit in an unsigned long, and DOMAIN_MAX_ADDR
  67   to match. That way, we can use 'unsigned long' for PFNs with impunity. */
  68#define DOMAIN_MAX_PFN(gaw)	((unsigned long) min_t(uint64_t, \
  69				__DOMAIN_MAX_PFN(gaw), (unsigned long)-1))
  70#define DOMAIN_MAX_ADDR(gaw)	(((uint64_t)__DOMAIN_MAX_PFN(gaw)) << VTD_PAGE_SHIFT)
  71
  72#define IOVA_PFN(addr)		((addr) >> PAGE_SHIFT)
  73#define DMA_32BIT_PFN		IOVA_PFN(DMA_BIT_MASK(32))
  74#define DMA_64BIT_PFN		IOVA_PFN(DMA_BIT_MASK(64))
  75
  76/* page table handling */
  77#define LEVEL_STRIDE		(9)
  78#define LEVEL_MASK		(((u64)1 << LEVEL_STRIDE) - 1)
  79
  80static inline int agaw_to_level(int agaw)
  81{
  82	return agaw + 2;
  83}
  84
  85static inline int agaw_to_width(int agaw)
  86{
  87	return 30 + agaw * LEVEL_STRIDE;
  88}
  89
  90static inline int width_to_agaw(int width)
  91{
  92	return (width - 30) / LEVEL_STRIDE;
  93}
  94
  95static inline unsigned int level_to_offset_bits(int level)
  96{
  97	return (level - 1) * LEVEL_STRIDE;
  98}
  99
 100static inline int pfn_level_offset(unsigned long pfn, int level)
 101{
 102	return (pfn >> level_to_offset_bits(level)) & LEVEL_MASK;
 103}
 104
 105static inline unsigned long level_mask(int level)
 106{
 107	return -1UL << level_to_offset_bits(level);
 108}
 109
 110static inline unsigned long level_size(int level)
 111{
 112	return 1UL << level_to_offset_bits(level);
 113}
 114
 115static inline unsigned long align_to_level(unsigned long pfn, int level)
 116{
 117	return (pfn + level_size(level) - 1) & level_mask(level);
 118}
 119
 120static inline unsigned long lvl_to_nr_pages(unsigned int lvl)
 121{
 122	return  1 << ((lvl - 1) * LEVEL_STRIDE);
 123}
 124
 125/* VT-d pages must always be _smaller_ than MM pages. Otherwise things
 126   are never going to work. */
 127static inline unsigned long dma_to_mm_pfn(unsigned long dma_pfn)
 128{
 129	return dma_pfn >> (PAGE_SHIFT - VTD_PAGE_SHIFT);
 130}
 131
 132static inline unsigned long mm_to_dma_pfn(unsigned long mm_pfn)
 133{
 134	return mm_pfn << (PAGE_SHIFT - VTD_PAGE_SHIFT);
 135}
 136static inline unsigned long page_to_dma_pfn(struct page *pg)
 137{
 138	return mm_to_dma_pfn(page_to_pfn(pg));
 139}
 140static inline unsigned long virt_to_dma_pfn(void *p)
 141{
 142	return page_to_dma_pfn(virt_to_page(p));
 143}
 144
 145/* global iommu list, set NULL for ignored DMAR units */
 146static struct intel_iommu **g_iommus;
 147
 148static void __init check_tylersburg_isoch(void);
 149static int rwbf_quirk;
 150
 151/*
 152 * set to 1 to panic kernel if can't successfully enable VT-d
 153 * (used when kernel is launched w/ TXT)
 154 */
 155static int force_on = 0;
 156
 157/*
 158 * 0: Present
 159 * 1-11: Reserved
 160 * 12-63: Context Ptr (12 - (haw-1))
 161 * 64-127: Reserved
 162 */
 163struct root_entry {
 164	u64	val;
 165	u64	rsvd1;
 166};
 167#define ROOT_ENTRY_NR (VTD_PAGE_SIZE/sizeof(struct root_entry))
 168static inline bool root_present(struct root_entry *root)
 169{
 170	return (root->val & 1);
 171}
 172static inline void set_root_present(struct root_entry *root)
 173{
 174	root->val |= 1;
 175}
 176static inline void set_root_value(struct root_entry *root, unsigned long value)
 177{
 178	root->val |= value & VTD_PAGE_MASK;
 179}
 180
 181static inline struct context_entry *
 182get_context_addr_from_root(struct root_entry *root)
 183{
 184	return (struct context_entry *)
 185		(root_present(root)?phys_to_virt(
 186		root->val & VTD_PAGE_MASK) :
 187		NULL);
 188}
 189
 190/*
 191 * low 64 bits:
 192 * 0: present
 193 * 1: fault processing disable
 194 * 2-3: translation type
 195 * 12-63: address space root
 196 * high 64 bits:
 197 * 0-2: address width
 198 * 3-6: aval
 199 * 8-23: domain id
 200 */
 201struct context_entry {
 202	u64 lo;
 203	u64 hi;
 204};
 205
 206static inline bool context_present(struct context_entry *context)
 207{
 208	return (context->lo & 1);
 209}
 210static inline void context_set_present(struct context_entry *context)
 211{
 212	context->lo |= 1;
 213}
 214
 215static inline void context_set_fault_enable(struct context_entry *context)
 216{
 217	context->lo &= (((u64)-1) << 2) | 1;
 218}
 219
 220static inline void context_set_translation_type(struct context_entry *context,
 221						unsigned long value)
 222{
 223	context->lo &= (((u64)-1) << 4) | 3;
 224	context->lo |= (value & 3) << 2;
 225}
 226
 227static inline void context_set_address_root(struct context_entry *context,
 228					    unsigned long value)
 229{
 230	context->lo |= value & VTD_PAGE_MASK;
 231}
 232
 233static inline void context_set_address_width(struct context_entry *context,
 234					     unsigned long value)
 235{
 236	context->hi |= value & 7;
 237}
 238
 239static inline void context_set_domain_id(struct context_entry *context,
 240					 unsigned long value)
 241{
 242	context->hi |= (value & ((1 << 16) - 1)) << 8;
 243}
 244
 245static inline void context_clear_entry(struct context_entry *context)
 246{
 247	context->lo = 0;
 248	context->hi = 0;
 249}
 250
 251/*
 252 * 0: readable
 253 * 1: writable
 254 * 2-6: reserved
 255 * 7: super page
 256 * 8-10: available
 257 * 11: snoop behavior
 258 * 12-63: Host physcial address
 259 */
 260struct dma_pte {
 261	u64 val;
 262};
 263
 264static inline void dma_clear_pte(struct dma_pte *pte)
 265{
 266	pte->val = 0;
 267}
 268
 269static inline void dma_set_pte_readable(struct dma_pte *pte)
 270{
 271	pte->val |= DMA_PTE_READ;
 272}
 273
 274static inline void dma_set_pte_writable(struct dma_pte *pte)
 275{
 276	pte->val |= DMA_PTE_WRITE;
 277}
 278
 279static inline void dma_set_pte_snp(struct dma_pte *pte)
 280{
 281	pte->val |= DMA_PTE_SNP;
 282}
 283
 284static inline void dma_set_pte_prot(struct dma_pte *pte, unsigned long prot)
 285{
 286	pte->val = (pte->val & ~3) | (prot & 3);
 287}
 288
 289static inline u64 dma_pte_addr(struct dma_pte *pte)
 290{
 291#ifdef CONFIG_64BIT
 292	return pte->val & VTD_PAGE_MASK;
 293#else
 294	/* Must have a full atomic 64-bit read */
 295	return  __cmpxchg64(&pte->val, 0ULL, 0ULL) & VTD_PAGE_MASK;
 296#endif
 297}
 298
 299static inline void dma_set_pte_pfn(struct dma_pte *pte, unsigned long pfn)
 300{
 301	pte->val |= (uint64_t)pfn << VTD_PAGE_SHIFT;
 302}
 303
 304static inline bool dma_pte_present(struct dma_pte *pte)
 305{
 306	return (pte->val & 3) != 0;
 307}
 308
 309static inline bool dma_pte_superpage(struct dma_pte *pte)
 310{
 311	return (pte->val & (1 << 7));
 312}
 313
 314static inline int first_pte_in_page(struct dma_pte *pte)
 315{
 316	return !((unsigned long)pte & ~VTD_PAGE_MASK);
 317}
 318
 319/*
 320 * This domain is a statically identity mapping domain.
 321 *	1. This domain creats a static 1:1 mapping to all usable memory.
 322 * 	2. It maps to each iommu if successful.
 323 *	3. Each iommu mapps to this domain if successful.
 324 */
 325static struct dmar_domain *si_domain;
 326static int hw_pass_through = 1;
 327
 328/* devices under the same p2p bridge are owned in one domain */
 329#define DOMAIN_FLAG_P2P_MULTIPLE_DEVICES (1 << 0)
 330
 331/* domain represents a virtual machine, more than one devices
 332 * across iommus may be owned in one domain, e.g. kvm guest.
 333 */
 334#define DOMAIN_FLAG_VIRTUAL_MACHINE	(1 << 1)
 335
 336/* si_domain contains mulitple devices */
 337#define DOMAIN_FLAG_STATIC_IDENTITY	(1 << 2)
 338
 339struct dmar_domain {
 340	int	id;			/* domain id */
 341	int	nid;			/* node id */
 342	unsigned long iommu_bmp;	/* bitmap of iommus this domain uses*/
 343
 344	struct list_head devices; 	/* all devices' list */
 345	struct iova_domain iovad;	/* iova's that belong to this domain */
 346
 347	struct dma_pte	*pgd;		/* virtual address */
 348	int		gaw;		/* max guest address width */
 349
 350	/* adjusted guest address width, 0 is level 2 30-bit */
 351	int		agaw;
 352
 353	int		flags;		/* flags to find out type of domain */
 354
 355	int		iommu_coherency;/* indicate coherency of iommu access */
 356	int		iommu_snooping; /* indicate snooping control feature*/
 357	int		iommu_count;	/* reference count of iommu */
 358	int		iommu_superpage;/* Level of superpages supported:
 359					   0 == 4KiB (no superpages), 1 == 2MiB,
 360					   2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
 361	spinlock_t	iommu_lock;	/* protect iommu set in domain */
 362	u64		max_addr;	/* maximum mapped address */
 363};
 364
 365/* PCI domain-device relationship */
 366struct device_domain_info {
 367	struct list_head link;	/* link to domain siblings */
 368	struct list_head global; /* link to global list */
 369	int segment;		/* PCI domain */
 370	u8 bus;			/* PCI bus number */
 371	u8 devfn;		/* PCI devfn number */
 372	struct pci_dev *dev; /* it's NULL for PCIe-to-PCI bridge */
 373	struct intel_iommu *iommu; /* IOMMU used by this device */
 374	struct dmar_domain *domain; /* pointer to domain */
 375};
 376
 377static void flush_unmaps_timeout(unsigned long data);
 378
 379DEFINE_TIMER(unmap_timer,  flush_unmaps_timeout, 0, 0);
 380
 381#define HIGH_WATER_MARK 250
 382struct deferred_flush_tables {
 383	int next;
 384	struct iova *iova[HIGH_WATER_MARK];
 385	struct dmar_domain *domain[HIGH_WATER_MARK];
 386};
 387
 388static struct deferred_flush_tables *deferred_flush;
 389
 390/* bitmap for indexing intel_iommus */
 391static int g_num_of_iommus;
 392
 393static DEFINE_SPINLOCK(async_umap_flush_lock);
 394static LIST_HEAD(unmaps_to_do);
 395
 396static int timer_on;
 397static long list_size;
 398
 399static void domain_remove_dev_info(struct dmar_domain *domain);
 400
 401#ifdef CONFIG_DMAR_DEFAULT_ON
 402int dmar_disabled = 0;
 403#else
 404int dmar_disabled = 1;
 405#endif /*CONFIG_DMAR_DEFAULT_ON*/
 406
 407static int dmar_map_gfx = 1;
 408static int dmar_forcedac;
 409static int intel_iommu_strict;
 410static int intel_iommu_superpage = 1;
 411
 412int intel_iommu_gfx_mapped;
 413EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped);
 414
 415#define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))
 416static DEFINE_SPINLOCK(device_domain_lock);
 417static LIST_HEAD(device_domain_list);
 418
 419static struct iommu_ops intel_iommu_ops;
 420
 421static int __init intel_iommu_setup(char *str)
 422{
 423	if (!str)
 424		return -EINVAL;
 425	while (*str) {
 426		if (!strncmp(str, "on", 2)) {
 427			dmar_disabled = 0;
 428			printk(KERN_INFO "Intel-IOMMU: enabled\n");
 429		} else if (!strncmp(str, "off", 3)) {
 430			dmar_disabled = 1;
 431			printk(KERN_INFO "Intel-IOMMU: disabled\n");
 432		} else if (!strncmp(str, "igfx_off", 8)) {
 433			dmar_map_gfx = 0;
 434			printk(KERN_INFO
 435				"Intel-IOMMU: disable GFX device mapping\n");
 436		} else if (!strncmp(str, "forcedac", 8)) {
 437			printk(KERN_INFO
 438				"Intel-IOMMU: Forcing DAC for PCI devices\n");
 439			dmar_forcedac = 1;
 440		} else if (!strncmp(str, "strict", 6)) {
 441			printk(KERN_INFO
 442				"Intel-IOMMU: disable batched IOTLB flush\n");
 443			intel_iommu_strict = 1;
 444		} else if (!strncmp(str, "sp_off", 6)) {
 445			printk(KERN_INFO
 446				"Intel-IOMMU: disable supported super page\n");
 447			intel_iommu_superpage = 0;
 448		}
 449
 450		str += strcspn(str, ",");
 451		while (*str == ',')
 452			str++;
 453	}
 454	return 0;
 455}
 456__setup("intel_iommu=", intel_iommu_setup);
 457
 458static struct kmem_cache *iommu_domain_cache;
 459static struct kmem_cache *iommu_devinfo_cache;
 460static struct kmem_cache *iommu_iova_cache;
 461
 462static inline void *alloc_pgtable_page(int node)
 463{
 464	struct page *page;
 465	void *vaddr = NULL;
 466
 467	page = alloc_pages_node(node, GFP_ATOMIC | __GFP_ZERO, 0);
 468	if (page)
 469		vaddr = page_address(page);
 470	return vaddr;
 471}
 472
 473static inline void free_pgtable_page(void *vaddr)
 474{
 475	free_page((unsigned long)vaddr);
 476}
 477
 478static inline void *alloc_domain_mem(void)
 479{
 480	return kmem_cache_alloc(iommu_domain_cache, GFP_ATOMIC);
 481}
 482
 483static void free_domain_mem(void *vaddr)
 484{
 485	kmem_cache_free(iommu_domain_cache, vaddr);
 486}
 487
 488static inline void * alloc_devinfo_mem(void)
 489{
 490	return kmem_cache_alloc(iommu_devinfo_cache, GFP_ATOMIC);
 491}
 492
 493static inline void free_devinfo_mem(void *vaddr)
 494{
 495	kmem_cache_free(iommu_devinfo_cache, vaddr);
 496}
 497
 498struct iova *alloc_iova_mem(void)
 499{
 500	return kmem_cache_alloc(iommu_iova_cache, GFP_ATOMIC);
 501}
 502
 503void free_iova_mem(struct iova *iova)
 504{
 505	kmem_cache_free(iommu_iova_cache, iova);
 506}
 507
 508
 509static int __iommu_calculate_agaw(struct intel_iommu *iommu, int max_gaw)
 510{
 511	unsigned long sagaw;
 512	int agaw = -1;
 513
 514	sagaw = cap_sagaw(iommu->cap);
 515	for (agaw = width_to_agaw(max_gaw);
 516	     agaw >= 0; agaw--) {
 517		if (test_bit(agaw, &sagaw))
 518			break;
 519	}
 520
 521	return agaw;
 522}
 523
 524/*
 525 * Calculate max SAGAW for each iommu.
 526 */
 527int iommu_calculate_max_sagaw(struct intel_iommu *iommu)
 528{
 529	return __iommu_calculate_agaw(iommu, MAX_AGAW_WIDTH);
 530}
 531
 532/*
 533 * calculate agaw for each iommu.
 534 * "SAGAW" may be different across iommus, use a default agaw, and
 535 * get a supported less agaw for iommus that don't support the default agaw.
 536 */
 537int iommu_calculate_agaw(struct intel_iommu *iommu)
 538{
 539	return __iommu_calculate_agaw(iommu, DEFAULT_DOMAIN_ADDRESS_WIDTH);
 540}
 541
 542/* This functionin only returns single iommu in a domain */
 543static struct intel_iommu *domain_get_iommu(struct dmar_domain *domain)
 544{
 545	int iommu_id;
 546
 547	/* si_domain and vm domain should not get here. */
 548	BUG_ON(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE);
 549	BUG_ON(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY);
 550
 551	iommu_id = find_first_bit(&domain->iommu_bmp, g_num_of_iommus);
 552	if (iommu_id < 0 || iommu_id >= g_num_of_iommus)
 553		return NULL;
 554
 555	return g_iommus[iommu_id];
 556}
 557
 558static void domain_update_iommu_coherency(struct dmar_domain *domain)
 559{
 560	int i;
 561
 562	domain->iommu_coherency = 1;
 563
 564	for_each_set_bit(i, &domain->iommu_bmp, g_num_of_iommus) {
 565		if (!ecap_coherent(g_iommus[i]->ecap)) {
 566			domain->iommu_coherency = 0;
 567			break;
 568		}
 569	}
 570}
 571
 572static void domain_update_iommu_snooping(struct dmar_domain *domain)
 573{
 574	int i;
 575
 576	domain->iommu_snooping = 1;
 577
 578	for_each_set_bit(i, &domain->iommu_bmp, g_num_of_iommus) {
 579		if (!ecap_sc_support(g_iommus[i]->ecap)) {
 580			domain->iommu_snooping = 0;
 581			break;
 582		}
 583	}
 584}
 585
 586static void domain_update_iommu_superpage(struct dmar_domain *domain)
 587{
 588	struct dmar_drhd_unit *drhd;
 589	struct intel_iommu *iommu = NULL;
 590	int mask = 0xf;
 591
 592	if (!intel_iommu_superpage) {
 593		domain->iommu_superpage = 0;
 594		return;
 595	}
 596
 597	/* set iommu_superpage to the smallest common denominator */
 598	for_each_active_iommu(iommu, drhd) {
 599		mask &= cap_super_page_val(iommu->cap);
 600		if (!mask) {
 601			break;
 602		}
 603	}
 604	domain->iommu_superpage = fls(mask);
 605}
 606
 607/* Some capabilities may be different across iommus */
 608static void domain_update_iommu_cap(struct dmar_domain *domain)
 609{
 610	domain_update_iommu_coherency(domain);
 611	domain_update_iommu_snooping(domain);
 612	domain_update_iommu_superpage(domain);
 613}
 614
 615static struct intel_iommu *device_to_iommu(int segment, u8 bus, u8 devfn)
 616{
 617	struct dmar_drhd_unit *drhd = NULL;
 618	int i;
 619
 620	for_each_drhd_unit(drhd) {
 621		if (drhd->ignored)
 622			continue;
 623		if (segment != drhd->segment)
 624			continue;
 625
 626		for (i = 0; i < drhd->devices_cnt; i++) {
 627			if (drhd->devices[i] &&
 628			    drhd->devices[i]->bus->number == bus &&
 629			    drhd->devices[i]->devfn == devfn)
 630				return drhd->iommu;
 631			if (drhd->devices[i] &&
 632			    drhd->devices[i]->subordinate &&
 633			    drhd->devices[i]->subordinate->number <= bus &&
 634			    drhd->devices[i]->subordinate->subordinate >= bus)
 635				return drhd->iommu;
 636		}
 637
 638		if (drhd->include_all)
 639			return drhd->iommu;
 640	}
 641
 642	return NULL;
 643}
 644
 645static void domain_flush_cache(struct dmar_domain *domain,
 646			       void *addr, int size)
 647{
 648	if (!domain->iommu_coherency)
 649		clflush_cache_range(addr, size);
 650}
 651
 652/* Gets context entry for a given bus and devfn */
 653static struct context_entry * device_to_context_entry(struct intel_iommu *iommu,
 654		u8 bus, u8 devfn)
 655{
 656	struct root_entry *root;
 657	struct context_entry *context;
 658	unsigned long phy_addr;
 659	unsigned long flags;
 660
 661	spin_lock_irqsave(&iommu->lock, flags);
 662	root = &iommu->root_entry[bus];
 663	context = get_context_addr_from_root(root);
 664	if (!context) {
 665		context = (struct context_entry *)
 666				alloc_pgtable_page(iommu->node);
 667		if (!context) {
 668			spin_unlock_irqrestore(&iommu->lock, flags);
 669			return NULL;
 670		}
 671		__iommu_flush_cache(iommu, (void *)context, CONTEXT_SIZE);
 672		phy_addr = virt_to_phys((void *)context);
 673		set_root_value(root, phy_addr);
 674		set_root_present(root);
 675		__iommu_flush_cache(iommu, root, sizeof(*root));
 676	}
 677	spin_unlock_irqrestore(&iommu->lock, flags);
 678	return &context[devfn];
 679}
 680
 681static int device_context_mapped(struct intel_iommu *iommu, u8 bus, u8 devfn)
 682{
 683	struct root_entry *root;
 684	struct context_entry *context;
 685	int ret;
 686	unsigned long flags;
 687
 688	spin_lock_irqsave(&iommu->lock, flags);
 689	root = &iommu->root_entry[bus];
 690	context = get_context_addr_from_root(root);
 691	if (!context) {
 692		ret = 0;
 693		goto out;
 694	}
 695	ret = context_present(&context[devfn]);
 696out:
 697	spin_unlock_irqrestore(&iommu->lock, flags);
 698	return ret;
 699}
 700
 701static void clear_context_table(struct intel_iommu *iommu, u8 bus, u8 devfn)
 702{
 703	struct root_entry *root;
 704	struct context_entry *context;
 705	unsigned long flags;
 706
 707	spin_lock_irqsave(&iommu->lock, flags);
 708	root = &iommu->root_entry[bus];
 709	context = get_context_addr_from_root(root);
 710	if (context) {
 711		context_clear_entry(&context[devfn]);
 712		__iommu_flush_cache(iommu, &context[devfn], \
 713			sizeof(*context));
 714	}
 715	spin_unlock_irqrestore(&iommu->lock, flags);
 716}
 717
 718static void free_context_table(struct intel_iommu *iommu)
 719{
 720	struct root_entry *root;
 721	int i;
 722	unsigned long flags;
 723	struct context_entry *context;
 724
 725	spin_lock_irqsave(&iommu->lock, flags);
 726	if (!iommu->root_entry) {
 727		goto out;
 728	}
 729	for (i = 0; i < ROOT_ENTRY_NR; i++) {
 730		root = &iommu->root_entry[i];
 731		context = get_context_addr_from_root(root);
 732		if (context)
 733			free_pgtable_page(context);
 734	}
 735	free_pgtable_page(iommu->root_entry);
 736	iommu->root_entry = NULL;
 737out:
 738	spin_unlock_irqrestore(&iommu->lock, flags);
 739}
 740
 741static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 742				      unsigned long pfn, int target_level)
 743{
 744	int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
 745	struct dma_pte *parent, *pte = NULL;
 746	int level = agaw_to_level(domain->agaw);
 747	int offset;
 748
 749	BUG_ON(!domain->pgd);
 750	BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
 751	parent = domain->pgd;
 752
 753	while (level > 0) {
 754		void *tmp_page;
 755
 756		offset = pfn_level_offset(pfn, level);
 757		pte = &parent[offset];
 758		if (!target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte)))
 759			break;
 760		if (level == target_level)
 761			break;
 762
 763		if (!dma_pte_present(pte)) {
 764			uint64_t pteval;
 765
 766			tmp_page = alloc_pgtable_page(domain->nid);
 767
 768			if (!tmp_page)
 769				return NULL;
 770
 771			domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
 772			pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
 773			if (cmpxchg64(&pte->val, 0ULL, pteval)) {
 774				/* Someone else set it while we were thinking; use theirs. */
 775				free_pgtable_page(tmp_page);
 776			} else {
 777				dma_pte_addr(pte);
 778				domain_flush_cache(domain, pte, sizeof(*pte));
 779			}
 780		}
 781		parent = phys_to_virt(dma_pte_addr(pte));
 782		level--;
 783	}
 784
 785	return pte;
 786}
 787
 788
 789/* return address's pte at specific level */
 790static struct dma_pte *dma_pfn_level_pte(struct dmar_domain *domain,
 791					 unsigned long pfn,
 792					 int level, int *large_page)
 793{
 794	struct dma_pte *parent, *pte = NULL;
 795	int total = agaw_to_level(domain->agaw);
 796	int offset;
 797
 798	parent = domain->pgd;
 799	while (level <= total) {
 800		offset = pfn_level_offset(pfn, total);
 801		pte = &parent[offset];
 802		if (level == total)
 803			return pte;
 804
 805		if (!dma_pte_present(pte)) {
 806			*large_page = total;
 807			break;
 808		}
 809
 810		if (pte->val & DMA_PTE_LARGE_PAGE) {
 811			*large_page = total;
 812			return pte;
 813		}
 814
 815		parent = phys_to_virt(dma_pte_addr(pte));
 816		total--;
 817	}
 818	return NULL;
 819}
 820
 821/* clear last level pte, a tlb flush should be followed */
 822static int dma_pte_clear_range(struct dmar_domain *domain,
 823				unsigned long start_pfn,
 824				unsigned long last_pfn)
 825{
 826	int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
 827	unsigned int large_page = 1;
 828	struct dma_pte *first_pte, *pte;
 829	int order;
 830
 831	BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
 832	BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
 833	BUG_ON(start_pfn > last_pfn);
 834
 835	/* we don't need lock here; nobody else touches the iova range */
 836	do {
 837		large_page = 1;
 838		first_pte = pte = dma_pfn_level_pte(domain, start_pfn, 1, &large_page);
 839		if (!pte) {
 840			start_pfn = align_to_level(start_pfn + 1, large_page + 1);
 841			continue;
 842		}
 843		do {
 844			dma_clear_pte(pte);
 845			start_pfn += lvl_to_nr_pages(large_page);
 846			pte++;
 847		} while (start_pfn <= last_pfn && !first_pte_in_page(pte));
 848
 849		domain_flush_cache(domain, first_pte,
 850				   (void *)pte - (void *)first_pte);
 851
 852	} while (start_pfn && start_pfn <= last_pfn);
 853
 854	order = (large_page - 1) * 9;
 855	return order;
 856}
 857
 858/* free page table pages. last level pte should already be cleared */
 859static void dma_pte_free_pagetable(struct dmar_domain *domain,
 860				   unsigned long start_pfn,
 861				   unsigned long last_pfn)
 862{
 863	int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
 864	struct dma_pte *first_pte, *pte;
 865	int total = agaw_to_level(domain->agaw);
 866	int level;
 867	unsigned long tmp;
 868	int large_page = 2;
 869
 870	BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
 871	BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
 872	BUG_ON(start_pfn > last_pfn);
 873
 874	/* We don't need lock here; nobody else touches the iova range */
 875	level = 2;
 876	while (level <= total) {
 877		tmp = align_to_level(start_pfn, level);
 878
 879		/* If we can't even clear one PTE at this level, we're done */
 880		if (tmp + level_size(level) - 1 > last_pfn)
 881			return;
 882
 883		do {
 884			large_page = level;
 885			first_pte = pte = dma_pfn_level_pte(domain, tmp, level, &large_page);
 886			if (large_page > level)
 887				level = large_page + 1;
 888			if (!pte) {
 889				tmp = align_to_level(tmp + 1, level + 1);
 890				continue;
 891			}
 892			do {
 893				if (dma_pte_present(pte)) {
 894					free_pgtable_page(phys_to_virt(dma_pte_addr(pte)));
 895					dma_clear_pte(pte);
 896				}
 897				pte++;
 898				tmp += level_size(level);
 899			} while (!first_pte_in_page(pte) &&
 900				 tmp + level_size(level) - 1 <= last_pfn);
 901
 902			domain_flush_cache(domain, first_pte,
 903					   (void *)pte - (void *)first_pte);
 904			
 905		} while (tmp && tmp + level_size(level) - 1 <= last_pfn);
 906		level++;
 907	}
 908	/* free pgd */
 909	if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
 910		free_pgtable_page(domain->pgd);
 911		domain->pgd = NULL;
 912	}
 913}
 914
 915/* iommu handling */
 916static int iommu_alloc_root_entry(struct intel_iommu *iommu)
 917{
 918	struct root_entry *root;
 919	unsigned long flags;
 920
 921	root = (struct root_entry *)alloc_pgtable_page(iommu->node);
 922	if (!root)
 923		return -ENOMEM;
 924
 925	__iommu_flush_cache(iommu, root, ROOT_SIZE);
 926
 927	spin_lock_irqsave(&iommu->lock, flags);
 928	iommu->root_entry = root;
 929	spin_unlock_irqrestore(&iommu->lock, flags);
 930
 931	return 0;
 932}
 933
 934static void iommu_set_root_entry(struct intel_iommu *iommu)
 935{
 936	void *addr;
 937	u32 sts;
 938	unsigned long flag;
 939
 940	addr = iommu->root_entry;
 941
 942	spin_lock_irqsave(&iommu->register_lock, flag);
 943	dmar_writeq(iommu->reg + DMAR_RTADDR_REG, virt_to_phys(addr));
 944
 945	writel(iommu->gcmd | DMA_GCMD_SRTP, iommu->reg + DMAR_GCMD_REG);
 946
 947	/* Make sure hardware complete it */
 948	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 949		      readl, (sts & DMA_GSTS_RTPS), sts);
 950
 951	spin_unlock_irqrestore(&iommu->register_lock, flag);
 952}
 953
 954static void iommu_flush_write_buffer(struct intel_iommu *iommu)
 955{
 956	u32 val;
 957	unsigned long flag;
 958
 959	if (!rwbf_quirk && !cap_rwbf(iommu->cap))
 960		return;
 961
 962	spin_lock_irqsave(&iommu->register_lock, flag);
 963	writel(iommu->gcmd | DMA_GCMD_WBF, iommu->reg + DMAR_GCMD_REG);
 964
 965	/* Make sure hardware complete it */
 966	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 967		      readl, (!(val & DMA_GSTS_WBFS)), val);
 968
 969	spin_unlock_irqrestore(&iommu->register_lock, flag);
 970}
 971
 972/* return value determine if we need a write buffer flush */
 973static void __iommu_flush_context(struct intel_iommu *iommu,
 974				  u16 did, u16 source_id, u8 function_mask,
 975				  u64 type)
 976{
 977	u64 val = 0;
 978	unsigned long flag;
 979
 980	switch (type) {
 981	case DMA_CCMD_GLOBAL_INVL:
 982		val = DMA_CCMD_GLOBAL_INVL;
 983		break;
 984	case DMA_CCMD_DOMAIN_INVL:
 985		val = DMA_CCMD_DOMAIN_INVL|DMA_CCMD_DID(did);
 986		break;
 987	case DMA_CCMD_DEVICE_INVL:
 988		val = DMA_CCMD_DEVICE_INVL|DMA_CCMD_DID(did)
 989			| DMA_CCMD_SID(source_id) | DMA_CCMD_FM(function_mask);
 990		break;
 991	default:
 992		BUG();
 993	}
 994	val |= DMA_CCMD_ICC;
 995
 996	spin_lock_irqsave(&iommu->register_lock, flag);
 997	dmar_writeq(iommu->reg + DMAR_CCMD_REG, val);
 998
 999	/* Make sure hardware complete it */
1000	IOMMU_WAIT_OP(iommu, DMAR_CCMD_REG,
1001		dmar_readq, (!(val & DMA_CCMD_ICC)), val);
1002
1003	spin_unlock_irqrestore(&iommu->register_lock, flag);
1004}
1005
1006/* return value determine if we need a write buffer flush */
1007static void __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did,
1008				u64 addr, unsigned int size_order, u64 type)
1009{
1010	int tlb_offset = ecap_iotlb_offset(iommu->ecap);
1011	u64 val = 0, val_iva = 0;
1012	unsigned long flag;
1013
1014	switch (type) {
1015	case DMA_TLB_GLOBAL_FLUSH:
1016		/* global flush doesn't need set IVA_REG */
1017		val = DMA_TLB_GLOBAL_FLUSH|DMA_TLB_IVT;
1018		break;
1019	case DMA_TLB_DSI_FLUSH:
1020		val = DMA_TLB_DSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did);
1021		break;
1022	case DMA_TLB_PSI_FLUSH:
1023		val = DMA_TLB_PSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did);
1024		/* Note: always flush non-leaf currently */
1025		val_iva = size_order | addr;
1026		break;
1027	default:
1028		BUG();
1029	}
1030	/* Note: set drain read/write */
1031#if 0
1032	/*
1033	 * This is probably to be super secure.. Looks like we can
1034	 * ignore it without any impact.
1035	 */
1036	if (cap_read_drain(iommu->cap))
1037		val |= DMA_TLB_READ_DRAIN;
1038#endif
1039	if (cap_write_drain(iommu->cap))
1040		val |= DMA_TLB_WRITE_DRAIN;
1041
1042	spin_lock_irqsave(&iommu->register_lock, flag);
1043	/* Note: Only uses first TLB reg currently */
1044	if (val_iva)
1045		dmar_writeq(iommu->reg + tlb_offset, val_iva);
1046	dmar_writeq(iommu->reg + tlb_offset + 8, val);
1047
1048	/* Make sure hardware complete it */
1049	IOMMU_WAIT_OP(iommu, tlb_offset + 8,
1050		dmar_readq, (!(val & DMA_TLB_IVT)), val);
1051
1052	spin_unlock_irqrestore(&iommu->register_lock, flag);
1053
1054	/* check IOTLB invalidation granularity */
1055	if (DMA_TLB_IAIG(val) == 0)
1056		printk(KERN_ERR"IOMMU: flush IOTLB failed\n");
1057	if (DMA_TLB_IAIG(val) != DMA_TLB_IIRG(type))
1058		pr_debug("IOMMU: tlb flush request %Lx, actual %Lx\n",
1059			(unsigned long long)DMA_TLB_IIRG(type),
1060			(unsigned long long)DMA_TLB_IAIG(val));
1061}
1062
1063static struct device_domain_info *iommu_support_dev_iotlb(
1064	struct dmar_domain *domain, int segment, u8 bus, u8 devfn)
1065{
1066	int found = 0;
1067	unsigned long flags;
1068	struct device_domain_info *info;
1069	struct intel_iommu *iommu = device_to_iommu(segment, bus, devfn);
1070
1071	if (!ecap_dev_iotlb_support(iommu->ecap))
1072		return NULL;
1073
1074	if (!iommu->qi)
1075		return NULL;
1076
1077	spin_lock_irqsave(&device_domain_lock, flags);
1078	list_for_each_entry(info, &domain->devices, link)
1079		if (info->bus == bus && info->devfn == devfn) {
1080			found = 1;
1081			break;
1082		}
1083	spin_unlock_irqrestore(&device_domain_lock, flags);
1084
1085	if (!found || !info->dev)
1086		return NULL;
1087
1088	if (!pci_find_ext_capability(info->dev, PCI_EXT_CAP_ID_ATS))
1089		return NULL;
1090
1091	if (!dmar_find_matched_atsr_unit(info->dev))
1092		return NULL;
1093
1094	info->iommu = iommu;
1095
1096	return info;
1097}
1098
1099static void iommu_enable_dev_iotlb(struct device_domain_info *info)
1100{
1101	if (!info)
1102		return;
1103
1104	pci_enable_ats(info->dev, VTD_PAGE_SHIFT);
1105}
1106
1107static void iommu_disable_dev_iotlb(struct device_domain_info *info)
1108{
1109	if (!info->dev || !pci_ats_enabled(info->dev))
1110		return;
1111
1112	pci_disable_ats(info->dev);
1113}
1114
1115static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
1116				  u64 addr, unsigned mask)
1117{
1118	u16 sid, qdep;
1119	unsigned long flags;
1120	struct device_domain_info *info;
1121
1122	spin_lock_irqsave(&device_domain_lock, flags);
1123	list_for_each_entry(info, &domain->devices, link) {
1124		if (!info->dev || !pci_ats_enabled(info->dev))
1125			continue;
1126
1127		sid = info->bus << 8 | info->devfn;
1128		qdep = pci_ats_queue_depth(info->dev);
1129		qi_flush_dev_iotlb(info->iommu, sid, qdep, addr, mask);
1130	}
1131	spin_unlock_irqrestore(&device_domain_lock, flags);
1132}
1133
1134static void iommu_flush_iotlb_psi(struct intel_iommu *iommu, u16 did,
1135				  unsigned long pfn, unsigned int pages, int map)
1136{
1137	unsigned int mask = ilog2(__roundup_pow_of_two(pages));
1138	uint64_t addr = (uint64_t)pfn << VTD_PAGE_SHIFT;
1139
1140	BUG_ON(pages == 0);
1141
1142	/*
1143	 * Fallback to domain selective flush if no PSI support or the size is
1144	 * too big.
1145	 * PSI requires page size to be 2 ^ x, and the base address is naturally
1146	 * aligned to the size
1147	 */
1148	if (!cap_pgsel_inv(iommu->cap) || mask > cap_max_amask_val(iommu->cap))
1149		iommu->flush.flush_iotlb(iommu, did, 0, 0,
1150						DMA_TLB_DSI_FLUSH);
1151	else
1152		iommu->flush.flush_iotlb(iommu, did, addr, mask,
1153						DMA_TLB_PSI_FLUSH);
1154
1155	/*
1156	 * In caching mode, changes of pages from non-present to present require
1157	 * flush. However, device IOTLB doesn't need to be flushed in this case.
1158	 */
1159	if (!cap_caching_mode(iommu->cap) || !map)
1160		iommu_flush_dev_iotlb(iommu->domains[did], addr, mask);
1161}
1162
1163static void iommu_disable_protect_mem_regions(struct intel_iommu *iommu)
1164{
1165	u32 pmen;
1166	unsigned long flags;
1167
1168	spin_lock_irqsave(&iommu->register_lock, flags);
1169	pmen = readl(iommu->reg + DMAR_PMEN_REG);
1170	pmen &= ~DMA_PMEN_EPM;
1171	writel(pmen, iommu->reg + DMAR_PMEN_REG);
1172
1173	/* wait for the protected region status bit to clear */
1174	IOMMU_WAIT_OP(iommu, DMAR_PMEN_REG,
1175		readl, !(pmen & DMA_PMEN_PRS), pmen);
1176
1177	spin_unlock_irqrestore(&iommu->register_lock, flags);
1178}
1179
1180static int iommu_enable_translation(struct intel_iommu *iommu)
1181{
1182	u32 sts;
1183	unsigned long flags;
1184
1185	spin_lock_irqsave(&iommu->register_lock, flags);
1186	iommu->gcmd |= DMA_GCMD_TE;
1187	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
1188
1189	/* Make sure hardware complete it */
1190	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
1191		      readl, (sts & DMA_GSTS_TES), sts);
1192
1193	spin_unlock_irqrestore(&iommu->register_lock, flags);
1194	return 0;
1195}
1196
1197static int iommu_disable_translation(struct intel_iommu *iommu)
1198{
1199	u32 sts;
1200	unsigned long flag;
1201
1202	spin_lock_irqsave(&iommu->register_lock, flag);
1203	iommu->gcmd &= ~DMA_GCMD_TE;
1204	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
1205
1206	/* Make sure hardware complete it */
1207	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
1208		      readl, (!(sts & DMA_GSTS_TES)), sts);
1209
1210	spin_unlock_irqrestore(&iommu->register_lock, flag);
1211	return 0;
1212}
1213
1214
1215static int iommu_init_domains(struct intel_iommu *iommu)
1216{
1217	unsigned long ndomains;
1218	unsigned long nlongs;
1219
1220	ndomains = cap_ndoms(iommu->cap);
1221	pr_debug("IOMMU %d: Number of Domains supportd <%ld>\n", iommu->seq_id,
1222			ndomains);
1223	nlongs = BITS_TO_LONGS(ndomains);
1224
1225	spin_lock_init(&iommu->lock);
1226
1227	/* TBD: there might be 64K domains,
1228	 * consider other allocation for future chip
1229	 */
1230	iommu->domain_ids = kcalloc(nlongs, sizeof(unsigned long), GFP_KERNEL);
1231	if (!iommu->domain_ids) {
1232		printk(KERN_ERR "Allocating domain id array failed\n");
1233		return -ENOMEM;
1234	}
1235	iommu->domains = kcalloc(ndomains, sizeof(struct dmar_domain *),
1236			GFP_KERNEL);
1237	if (!iommu->domains) {
1238		printk(KERN_ERR "Allocating domain array failed\n");
1239		return -ENOMEM;
1240	}
1241
1242	/*
1243	 * if Caching mode is set, then invalid translations are tagged
1244	 * with domainid 0. Hence we need to pre-allocate it.
1245	 */
1246	if (cap_caching_mode(iommu->cap))
1247		set_bit(0, iommu->domain_ids);
1248	return 0;
1249}
1250
1251
1252static void domain_exit(struct dmar_domain *domain);
1253static void vm_domain_exit(struct dmar_domain *domain);
1254
1255void free_dmar_iommu(struct intel_iommu *iommu)
1256{
1257	struct dmar_domain *domain;
1258	int i;
1259	unsigned long flags;
1260
1261	if ((iommu->domains) && (iommu->domain_ids)) {
1262		for_each_set_bit(i, iommu->domain_ids, cap_ndoms(iommu->cap)) {
1263			domain = iommu->domains[i];
1264			clear_bit(i, iommu->domain_ids);
1265
1266			spin_lock_irqsave(&domain->iommu_lock, flags);
1267			if (--domain->iommu_count == 0) {
1268				if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE)
1269					vm_domain_exit(domain);
1270				else
1271					domain_exit(domain);
1272			}
1273			spin_unlock_irqrestore(&domain->iommu_lock, flags);
1274		}
1275	}
1276
1277	if (iommu->gcmd & DMA_GCMD_TE)
1278		iommu_disable_translation(iommu);
1279
1280	if (iommu->irq) {
1281		irq_set_handler_data(iommu->irq, NULL);
1282		/* This will mask the irq */
1283		free_irq(iommu->irq, iommu);
1284		destroy_irq(iommu->irq);
1285	}
1286
1287	kfree(iommu->domains);
1288	kfree(iommu->domain_ids);
1289
1290	g_iommus[iommu->seq_id] = NULL;
1291
1292	/* if all iommus are freed, free g_iommus */
1293	for (i = 0; i < g_num_of_iommus; i++) {
1294		if (g_iommus[i])
1295			break;
1296	}
1297
1298	if (i == g_num_of_iommus)
1299		kfree(g_iommus);
1300
1301	/* free context mapping */
1302	free_context_table(iommu);
1303}
1304
1305static struct dmar_domain *alloc_domain(void)
1306{
1307	struct dmar_domain *domain;
1308
1309	domain = alloc_domain_mem();
1310	if (!domain)
1311		return NULL;
1312
1313	domain->nid = -1;
1314	memset(&domain->iommu_bmp, 0, sizeof(unsigned long));
1315	domain->flags = 0;
1316
1317	return domain;
1318}
1319
1320static int iommu_attach_domain(struct dmar_domain *domain,
1321			       struct intel_iommu *iommu)
1322{
1323	int num;
1324	unsigned long ndomains;
1325	unsigned long flags;
1326
1327	ndomains = cap_ndoms(iommu->cap);
1328
1329	spin_lock_irqsave(&iommu->lock, flags);
1330
1331	num = find_first_zero_bit(iommu->domain_ids, ndomains);
1332	if (num >= ndomains) {
1333		spin_unlock_irqrestore(&iommu->lock, flags);
1334		printk(KERN_ERR "IOMMU: no free domain ids\n");
1335		return -ENOMEM;
1336	}
1337
1338	domain->id = num;
1339	set_bit(num, iommu->domain_ids);
1340	set_bit(iommu->seq_id, &domain->iommu_bmp);
1341	iommu->domains[num] = domain;
1342	spin_unlock_irqrestore(&iommu->lock, flags);
1343
1344	return 0;
1345}
1346
1347static void iommu_detach_domain(struct dmar_domain *domain,
1348				struct intel_iommu *iommu)
1349{
1350	unsigned long flags;
1351	int num, ndomains;
1352	int found = 0;
1353
1354	spin_lock_irqsave(&iommu->lock, flags);
1355	ndomains = cap_ndoms(iommu->cap);
1356	for_each_set_bit(num, iommu->domain_ids, ndomains) {
1357		if (iommu->domains[num] == domain) {
1358			found = 1;
1359			break;
1360		}
1361	}
1362
1363	if (found) {
1364		clear_bit(num, iommu->domain_ids);
1365		clear_bit(iommu->seq_id, &domain->iommu_bmp);
1366		iommu->domains[num] = NULL;
1367	}
1368	spin_unlock_irqrestore(&iommu->lock, flags);
1369}
1370
1371static struct iova_domain reserved_iova_list;
1372static struct lock_class_key reserved_rbtree_key;
1373
1374static int dmar_init_reserved_ranges(void)
1375{
1376	struct pci_dev *pdev = NULL;
1377	struct iova *iova;
1378	int i;
1379
1380	init_iova_domain(&reserved_iova_list, DMA_32BIT_PFN);
1381
1382	lockdep_set_class(&reserved_iova_list.iova_rbtree_lock,
1383		&reserved_rbtree_key);
1384
1385	/* IOAPIC ranges shouldn't be accessed by DMA */
1386	iova = reserve_iova(&reserved_iova_list, IOVA_PFN(IOAPIC_RANGE_START),
1387		IOVA_PFN(IOAPIC_RANGE_END));
1388	if (!iova) {
1389		printk(KERN_ERR "Reserve IOAPIC range failed\n");
1390		return -ENODEV;
1391	}
1392
1393	/* Reserve all PCI MMIO to avoid peer-to-peer access */
1394	for_each_pci_dev(pdev) {
1395		struct resource *r;
1396
1397		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
1398			r = &pdev->resource[i];
1399			if (!r->flags || !(r->flags & IORESOURCE_MEM))
1400				continue;
1401			iova = reserve_iova(&reserved_iova_list,
1402					    IOVA_PFN(r->start),
1403					    IOVA_PFN(r->end));
1404			if (!iova) {
1405				printk(KERN_ERR "Reserve iova failed\n");
1406				return -ENODEV;
1407			}
1408		}
1409	}
1410	return 0;
1411}
1412
1413static void domain_reserve_special_ranges(struct dmar_domain *domain)
1414{
1415	copy_reserved_iova(&reserved_iova_list, &domain->iovad);
1416}
1417
1418static inline int guestwidth_to_adjustwidth(int gaw)
1419{
1420	int agaw;
1421	int r = (gaw - 12) % 9;
1422
1423	if (r == 0)
1424		agaw = gaw;
1425	else
1426		agaw = gaw + 9 - r;
1427	if (agaw > 64)
1428		agaw = 64;
1429	return agaw;
1430}
1431
1432static int domain_init(struct dmar_domain *domain, int guest_width)
1433{
1434	struct intel_iommu *iommu;
1435	int adjust_width, agaw;
1436	unsigned long sagaw;
1437
1438	init_iova_domain(&domain->iovad, DMA_32BIT_PFN);
1439	spin_lock_init(&domain->iommu_lock);
1440
1441	domain_reserve_special_ranges(domain);
1442
1443	/* calculate AGAW */
1444	iommu = domain_get_iommu(domain);
1445	if (guest_width > cap_mgaw(iommu->cap))
1446		guest_width = cap_mgaw(iommu->cap);
1447	domain->gaw = guest_width;
1448	adjust_width = guestwidth_to_adjustwidth(guest_width);
1449	agaw = width_to_agaw(adjust_width);
1450	sagaw = cap_sagaw(iommu->cap);
1451	if (!test_bit(agaw, &sagaw)) {
1452		/* hardware doesn't support it, choose a bigger one */
1453		pr_debug("IOMMU: hardware doesn't support agaw %d\n", agaw);
1454		agaw = find_next_bit(&sagaw, 5, agaw);
1455		if (agaw >= 5)
1456			return -ENODEV;
1457	}
1458	domain->agaw = agaw;
1459	INIT_LIST_HEAD(&domain->devices);
1460
1461	if (ecap_coherent(iommu->ecap))
1462		domain->iommu_coherency = 1;
1463	else
1464		domain->iommu_coherency = 0;
1465
1466	if (ecap_sc_support(iommu->ecap))
1467		domain->iommu_snooping = 1;
1468	else
1469		domain->iommu_snooping = 0;
1470
1471	domain->iommu_superpage = fls(cap_super_page_val(iommu->cap));
1472	domain->iommu_count = 1;
1473	domain->nid = iommu->node;
1474
1475	/* always allocate the top pgd */
1476	domain->pgd = (struct dma_pte *)alloc_pgtable_page(domain->nid);
1477	if (!domain->pgd)
1478		return -ENOMEM;
1479	__iommu_flush_cache(iommu, domain->pgd, PAGE_SIZE);
1480	return 0;
1481}
1482
1483static void domain_exit(struct dmar_domain *domain)
1484{
1485	struct dmar_drhd_unit *drhd;
1486	struct intel_iommu *iommu;
1487
1488	/* Domain 0 is reserved, so dont process it */
1489	if (!domain)
1490		return;
1491
1492	/* Flush any lazy unmaps that may reference this domain */
1493	if (!intel_iommu_strict)
1494		flush_unmaps_timeout(0);
1495
1496	domain_remove_dev_info(domain);
1497	/* destroy iovas */
1498	put_iova_domain(&domain->iovad);
1499
1500	/* clear ptes */
1501	dma_pte_clear_range(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
1502
1503	/* free page tables */
1504	dma_pte_free_pagetable(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
1505
1506	for_each_active_iommu(iommu, drhd)
1507		if (test_bit(iommu->seq_id, &domain->iommu_bmp))
1508			iommu_detach_domain(domain, iommu);
1509
1510	free_domain_mem(domain);
1511}
1512
1513static int domain_context_mapping_one(struct dmar_domain *domain, int segment,
1514				 u8 bus, u8 devfn, int translation)
1515{
1516	struct context_entry *context;
1517	unsigned long flags;
1518	struct intel_iommu *iommu;
1519	struct dma_pte *pgd;
1520	unsigned long num;
1521	unsigned long ndomains;
1522	int id;
1523	int agaw;
1524	struct device_domain_info *info = NULL;
1525
1526	pr_debug("Set context mapping for %02x:%02x.%d\n",
1527		bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
1528
1529	BUG_ON(!domain->pgd);
1530	BUG_ON(translation != CONTEXT_TT_PASS_THROUGH &&
1531	       translation != CONTEXT_TT_MULTI_LEVEL);
1532
1533	iommu = device_to_iommu(segment, bus, devfn);
1534	if (!iommu)
1535		return -ENODEV;
1536
1537	context = device_to_context_entry(iommu, bus, devfn);
1538	if (!context)
1539		return -ENOMEM;
1540	spin_lock_irqsave(&iommu->lock, flags);
1541	if (context_present(context)) {
1542		spin_unlock_irqrestore(&iommu->lock, flags);
1543		return 0;
1544	}
1545
1546	id = domain->id;
1547	pgd = domain->pgd;
1548
1549	if (domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE ||
1550	    domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) {
1551		int found = 0;
1552
1553		/* find an available domain id for this device in iommu */
1554		ndomains = cap_ndoms(iommu->cap);
1555		for_each_set_bit(num, iommu->domain_ids, ndomains) {
1556			if (iommu->domains[num] == domain) {
1557				id = num;
1558				found = 1;
1559				break;
1560			}
1561		}
1562
1563		if (found == 0) {
1564			num = find_first_zero_bit(iommu->domain_ids, ndomains);
1565			if (num >= ndomains) {
1566				spin_unlock_irqrestore(&iommu->lock, flags);
1567				printk(KERN_ERR "IOMMU: no free domain ids\n");
1568				return -EFAULT;
1569			}
1570
1571			set_bit(num, iommu->domain_ids);
1572			iommu->domains[num] = domain;
1573			id = num;
1574		}
1575
1576		/* Skip top levels of page tables for
1577		 * iommu which has less agaw than default.
1578		 * Unnecessary for PT mode.
1579		 */
1580		if (translation != CONTEXT_TT_PASS_THROUGH) {
1581			for (agaw = domain->agaw; agaw != iommu->agaw; agaw--) {
1582				pgd = phys_to_virt(dma_pte_addr(pgd));
1583				if (!dma_pte_present(pgd)) {
1584					spin_unlock_irqrestore(&iommu->lock, flags);
1585					return -ENOMEM;
1586				}
1587			}
1588		}
1589	}
1590
1591	context_set_domain_id(context, id);
1592
1593	if (translation != CONTEXT_TT_PASS_THROUGH) {
1594		info = iommu_support_dev_iotlb(domain, segment, bus, devfn);
1595		translation = info ? CONTEXT_TT_DEV_IOTLB :
1596				     CONTEXT_TT_MULTI_LEVEL;
1597	}
1598	/*
1599	 * In pass through mode, AW must be programmed to indicate the largest
1600	 * AGAW value supported by hardware. And ASR is ignored by hardware.
1601	 */
1602	if (unlikely(translation == CONTEXT_TT_PASS_THROUGH))
1603		context_set_address_width(context, iommu->msagaw);
1604	else {
1605		context_set_address_root(context, virt_to_phys(pgd));
1606		context_set_address_width(context, iommu->agaw);
1607	}
1608
1609	context_set_translation_type(context, translation);
1610	context_set_fault_enable(context);
1611	context_set_present(context);
1612	domain_flush_cache(domain, context, sizeof(*context));
1613
1614	/*
1615	 * It's a non-present to present mapping. If hardware doesn't cache
1616	 * non-present entry we only need to flush the write-buffer. If the
1617	 * _does_ cache non-present entries, then it does so in the special
1618	 * domain #0, which we have to flush:
1619	 */
1620	if (cap_caching_mode(iommu->cap)) {
1621		iommu->flush.flush_context(iommu, 0,
1622					   (((u16)bus) << 8) | devfn,
1623					   DMA_CCMD_MASK_NOBIT,
1624					   DMA_CCMD_DEVICE_INVL);
1625		iommu->flush.flush_iotlb(iommu, domain->id, 0, 0, DMA_TLB_DSI_FLUSH);
1626	} else {
1627		iommu_flush_write_buffer(iommu);
1628	}
1629	iommu_enable_dev_iotlb(info);
1630	spin_unlock_irqrestore(&iommu->lock, flags);
1631
1632	spin_lock_irqsave(&domain->iommu_lock, flags);
1633	if (!test_and_set_bit(iommu->seq_id, &domain->iommu_bmp)) {
1634		domain->iommu_count++;
1635		if (domain->iommu_count == 1)
1636			domain->nid = iommu->node;
1637		domain_update_iommu_cap(domain);
1638	}
1639	spin_unlock_irqrestore(&domain->iommu_lock, flags);
1640	return 0;
1641}
1642
1643static int
1644domain_context_mapping(struct dmar_domain *domain, struct pci_dev *pdev,
1645			int translation)
1646{
1647	int ret;
1648	struct pci_dev *tmp, *parent;
1649
1650	ret = domain_context_mapping_one(domain, pci_domain_nr(pdev->bus),
1651					 pdev->bus->number, pdev->devfn,
1652					 translation);
1653	if (ret)
1654		return ret;
1655
1656	/* dependent device mapping */
1657	tmp = pci_find_upstream_pcie_bridge(pdev);
1658	if (!tmp)
1659		return 0;
1660	/* Secondary interface's bus number and devfn 0 */
1661	parent = pdev->bus->self;
1662	while (parent != tmp) {
1663		ret = domain_context_mapping_one(domain,
1664						 pci_domain_nr(parent->bus),
1665						 parent->bus->number,
1666						 parent->devfn, translation);
1667		if (ret)
1668			return ret;
1669		parent = parent->bus->self;
1670	}
1671	if (pci_is_pcie(tmp)) /* this is a PCIe-to-PCI bridge */
1672		return domain_context_mapping_one(domain,
1673					pci_domain_nr(tmp->subordinate),
1674					tmp->subordinate->number, 0,
1675					translation);
1676	else /* this is a legacy PCI bridge */
1677		return domain_context_mapping_one(domain,
1678						  pci_domain_nr(tmp->bus),
1679						  tmp->bus->number,
1680						  tmp->devfn,
1681						  translation);
1682}
1683
1684static int domain_context_mapped(struct pci_dev *pdev)
1685{
1686	int ret;
1687	struct pci_dev *tmp, *parent;
1688	struct intel_iommu *iommu;
1689
1690	iommu = device_to_iommu(pci_domain_nr(pdev->bus), pdev->bus->number,
1691				pdev->devfn);
1692	if (!iommu)
1693		return -ENODEV;
1694
1695	ret = device_context_mapped(iommu, pdev->bus->number, pdev->devfn);
1696	if (!ret)
1697		return ret;
1698	/* dependent device mapping */
1699	tmp = pci_find_upstream_pcie_bridge(pdev);
1700	if (!tmp)
1701		return ret;
1702	/* Secondary interface's bus number and devfn 0 */
1703	parent = pdev->bus->self;
1704	while (parent != tmp) {
1705		ret = device_context_mapped(iommu, parent->bus->number,
1706					    parent->devfn);
1707		if (!ret)
1708			return ret;
1709		parent = parent->bus->self;
1710	}
1711	if (pci_is_pcie(tmp))
1712		return device_context_mapped(iommu, tmp->subordinate->number,
1713					     0);
1714	else
1715		return device_context_mapped(iommu, tmp->bus->number,
1716					     tmp->devfn);
1717}
1718
1719/* Returns a number of VTD pages, but aligned to MM page size */
1720static inline unsigned long aligned_nrpages(unsigned long host_addr,
1721					    size_t size)
1722{
1723	host_addr &= ~PAGE_MASK;
1724	return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;
1725}
1726
1727/* Return largest possible superpage level for a given mapping */
1728static inline int hardware_largepage_caps(struct dmar_domain *domain,
1729					  unsigned long iov_pfn,
1730					  unsigned long phy_pfn,
1731					  unsigned long pages)
1732{
1733	int support, level = 1;
1734	unsigned long pfnmerge;
1735
1736	support = domain->iommu_superpage;
1737
1738	/* To use a large page, the virtual *and* physical addresses
1739	   must be aligned to 2MiB/1GiB/etc. Lower bits set in either
1740	   of them will mean we have to use smaller pages. So just
1741	   merge them and check both at once. */
1742	pfnmerge = iov_pfn | phy_pfn;
1743
1744	while (support && !(pfnmerge & ~VTD_STRIDE_MASK)) {
1745		pages >>= VTD_STRIDE_SHIFT;
1746		if (!pages)
1747			break;
1748		pfnmerge >>= VTD_STRIDE_SHIFT;
1749		level++;
1750		support--;
1751	}
1752	return level;
1753}
1754
1755static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
1756			    struct scatterlist *sg, unsigned long phys_pfn,
1757			    unsigned long nr_pages, int prot)
1758{
1759	struct dma_pte *first_pte = NULL, *pte = NULL;
1760	phys_addr_t uninitialized_var(pteval);
1761	int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
1762	unsigned long sg_res;
1763	unsigned int largepage_lvl = 0;
1764	unsigned long lvl_pages = 0;
1765
1766	BUG_ON(addr_width < BITS_PER_LONG && (iov_pfn + nr_pages - 1) >> addr_width);
1767
1768	if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
1769		return -EINVAL;
1770
1771	prot &= DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP;
1772
1773	if (sg)
1774		sg_res = 0;
1775	else {
1776		sg_res = nr_pages + 1;
1777		pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | prot;
1778	}
1779
1780	while (nr_pages > 0) {
1781		uint64_t tmp;
1782
1783		if (!sg_res) {
1784			sg_res = aligned_nrpages(sg->offset, sg->length);
1785			sg->dma_address = ((dma_addr_t)iov_pfn << VTD_PAGE_SHIFT) + sg->offset;
1786			sg->dma_length = sg->length;
1787			pteval = page_to_phys(sg_page(sg)) | prot;
1788			phys_pfn = pteval >> VTD_PAGE_SHIFT;
1789		}
1790
1791		if (!pte) {
1792			largepage_lvl = hardware_largepage_caps(domain, iov_pfn, phys_pfn, sg_res);
1793
1794			first_pte = pte = pfn_to_dma_pte(domain, iov_pfn, largepage_lvl);
1795			if (!pte)
1796				return -ENOMEM;
1797			/* It is large page*/
1798			if (largepage_lvl > 1)
1799				pteval |= DMA_PTE_LARGE_PAGE;
1800			else
1801				pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE;
1802
1803		}
1804		/* We don't need lock here, nobody else
1805		 * touches the iova range
1806		 */
1807		tmp = cmpxchg64_local(&pte->val, 0ULL, pteval);
1808		if (tmp) {
1809			static int dumps = 5;
1810			printk(KERN_CRIT "ERROR: DMA PTE for vPFN 0x%lx already set (to %llx not %llx)\n",
1811			       iov_pfn, tmp, (unsigned long long)pteval);
1812			if (dumps) {
1813				dumps--;
1814				debug_dma_dump_mappings(NULL);
1815			}
1816			WARN_ON(1);
1817		}
1818
1819		lvl_pages = lvl_to_nr_pages(largepage_lvl);
1820
1821		BUG_ON(nr_pages < lvl_pages);
1822		BUG_ON(sg_res < lvl_pages);
1823
1824		nr_pages -= lvl_pages;
1825		iov_pfn += lvl_pages;
1826		phys_pfn += lvl_pages;
1827		pteval += lvl_pages * VTD_PAGE_SIZE;
1828		sg_res -= lvl_pages;
1829
1830		/* If the next PTE would be the first in a new page, then we
1831		   need to flush the cache on the entries we've just written.
1832		   And then we'll need to recalculate 'pte', so clear it and
1833		   let it get set again in the if (!pte) block above.
1834
1835		   If we're done (!nr_pages) we need to flush the cache too.
1836
1837		   Also if we've been setting superpages, we may need to
1838		   recalculate 'pte' and switch back to smaller pages for the
1839		   end of the mapping, if the trailing size is not enough to
1840		   use another superpage (i.e. sg_res < lvl_pages). */
1841		pte++;
1842		if (!nr_pages || first_pte_in_page(pte) ||
1843		    (largepage_lvl > 1 && sg_res < lvl_pages)) {
1844			domain_flush_cache(domain, first_pte,
1845					   (void *)pte - (void *)first_pte);
1846			pte = NULL;
1847		}
1848
1849		if (!sg_res && nr_pages)
1850			sg = sg_next(sg);
1851	}
1852	return 0;
1853}
1854
1855static inline int domain_sg_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
1856				    struct scatterlist *sg, unsigned long nr_pages,
1857				    int prot)
1858{
1859	return __domain_mapping(domain, iov_pfn, sg, 0, nr_pages, prot);
1860}
1861
1862static inline int domain_pfn_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
1863				     unsigned long phys_pfn, unsigned long nr_pages,
1864				     int prot)
1865{
1866	return __domain_mapping(domain, iov_pfn, NULL, phys_pfn, nr_pages, prot);
1867}
1868
1869static void iommu_detach_dev(struct intel_iommu *iommu, u8 bus, u8 devfn)
1870{
1871	if (!iommu)
1872		return;
1873
1874	clear_context_table(iommu, bus, devfn);
1875	iommu->flush.flush_context(iommu, 0, 0, 0,
1876					   DMA_CCMD_GLOBAL_INVL);
1877	iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
1878}
1879
1880static void domain_remove_dev_info(struct dmar_domain *domain)
1881{
1882	struct device_domain_info *info;
1883	unsigned long flags;
1884	struct intel_iommu *iommu;
1885
1886	spin_lock_irqsave(&device_domain_lock, flags);
1887	while (!list_empty(&domain->devices)) {
1888		info = list_entry(domain->devices.next,
1889			struct device_domain_info, link);
1890		list_del(&info->link);
1891		list_del(&info->global);
1892		if (info->dev)
1893			info->dev->dev.archdata.iommu = NULL;
1894		spin_unlock_irqrestore(&device_domain_lock, flags);
1895
1896		iommu_disable_dev_iotlb(info);
1897		iommu = device_to_iommu(info->segment, info->bus, info->devfn);
1898		iommu_detach_dev(iommu, info->bus, info->devfn);
1899		free_devinfo_mem(info);
1900
1901		spin_lock_irqsave(&device_domain_lock, flags);
1902	}
1903	spin_unlock_irqrestore(&device_domain_lock, flags);
1904}
1905
1906/*
1907 * find_domain
1908 * Note: we use struct pci_dev->dev.archdata.iommu stores the info
1909 */
1910static struct dmar_domain *
1911find_domain(struct pci_dev *pdev)
1912{
1913	struct device_domain_info *info;
1914
1915	/* No lock here, assumes no domain exit in normal case */
1916	info = pdev->dev.archdata.iommu;
1917	if (info)
1918		return info->domain;
1919	return NULL;
1920}
1921
1922/* domain is initialized */
1923static struct dmar_domain *get_domain_for_dev(struct pci_dev *pdev, int gaw)
1924{
1925	struct dmar_domain *domain, *found = NULL;
1926	struct intel_iommu *iommu;
1927	struct dmar_drhd_unit *drhd;
1928	struct device_domain_info *info, *tmp;
1929	struct pci_dev *dev_tmp;
1930	unsigned long flags;
1931	int bus = 0, devfn = 0;
1932	int segment;
1933	int ret;
1934
1935	domain = find_domain(pdev);
1936	if (domain)
1937		return domain;
1938
1939	segment = pci_domain_nr(pdev->bus);
1940
1941	dev_tmp = pci_find_upstream_pcie_bridge(pdev);
1942	if (dev_tmp) {
1943		if (pci_is_pcie(dev_tmp)) {
1944			bus = dev_tmp->subordinate->number;
1945			devfn = 0;
1946		} else {
1947			bus = dev_tmp->bus->number;
1948			devfn = dev_tmp->devfn;
1949		}
1950		spin_lock_irqsave(&device_domain_lock, flags);
1951		list_for_each_entry(info, &device_domain_list, global) {
1952			if (info->segment == segment &&
1953			    info->bus == bus && info->devfn == devfn) {
1954				found = info->domain;
1955				break;
1956			}
1957		}
1958		spin_unlock_irqrestore(&device_domain_lock, flags);
1959		/* pcie-pci bridge already has a domain, uses it */
1960		if (found) {
1961			domain = found;
1962			goto found_domain;
1963		}
1964	}
1965
1966	domain = alloc_domain();
1967	if (!domain)
1968		goto error;
1969
1970	/* Allocate new domain for the device */
1971	drhd = dmar_find_matched_drhd_unit(pdev);
1972	if (!drhd) {
1973		printk(KERN_ERR "IOMMU: can't find DMAR for device %s\n",
1974			pci_name(pdev));
1975		return NULL;
1976	}
1977	iommu = drhd->iommu;
1978
1979	ret = iommu_attach_domain(domain, iommu);
1980	if (ret) {
1981		free_domain_mem(domain);
1982		goto error;
1983	}
1984
1985	if (domain_init(domain, gaw)) {
1986		domain_exit(domain);
1987		goto error;
1988	}
1989
1990	/* register pcie-to-pci device */
1991	if (dev_tmp) {
1992		info = alloc_devinfo_mem();
1993		if (!info) {
1994			domain_exit(domain);
1995			goto error;
1996		}
1997		info->segment = segment;
1998		info->bus = bus;
1999		info->devfn = devfn;
2000		info->dev = NULL;
2001		info->domain = domain;
2002		/* This domain is shared by devices under p2p bridge */
2003		domain->flags |= DOMAIN_FLAG_P2P_MULTIPLE_DEVICES;
2004
2005		/* pcie-to-pci bridge already has a domain, uses it */
2006		found = NULL;
2007		spin_lock_irqsave(&device_domain_lock, flags);
2008		list_for_each_entry(tmp, &device_domain_list, global) {
2009			if (tmp->segment == segment &&
2010			    tmp->bus == bus && tmp->devfn == devfn) {
2011				found = tmp->domain;
2012				break;
2013			}
2014		}
2015		if (found) {
2016			spin_unlock_irqrestore(&device_domain_lock, flags);
2017			free_devinfo_mem(info);
2018			domain_exit(domain);
2019			domain = found;
2020		} else {
2021			list_add(&info->link, &domain->devices);
2022			list_add(&info->global, &device_domain_list);
2023			spin_unlock_irqrestore(&device_domain_lock, flags);
2024		}
2025	}
2026
2027found_domain:
2028	info = alloc_devinfo_mem();
2029	if (!info)
2030		goto error;
2031	info->segment = segment;
2032	info->bus = pdev->bus->number;
2033	info->devfn = pdev->devfn;
2034	info->dev = pdev;
2035	info->domain = domain;
2036	spin_lock_irqsave(&device_domain_lock, flags);
2037	/* somebody is fast */
2038	found = find_domain(pdev);
2039	if (found != NULL) {
2040		spin_unlock_irqrestore(&device_domain_lock, flags);
2041		if (found != domain) {
2042			domain_exit(domain);
2043			domain = found;
2044		}
2045		free_devinfo_mem(info);
2046		return domain;
2047	}
2048	list_add(&info->link, &domain->devices);
2049	list_add(&info->global, &device_domain_list);
2050	pdev->dev.archdata.iommu = info;
2051	spin_unlock_irqrestore(&device_domain_lock, flags);
2052	return domain;
2053error:
2054	/* recheck it here, maybe others set it */
2055	return find_domain(pdev);
2056}
2057
2058static int iommu_identity_mapping;
2059#define IDENTMAP_ALL		1
2060#define IDENTMAP_GFX		2
2061#define IDENTMAP_AZALIA		4
2062
2063static int iommu_domain_identity_map(struct dmar_domain *domain,
2064				     unsigned long long start,
2065				     unsigned long long end)
2066{
2067	unsigned long first_vpfn = start >> VTD_PAGE_SHIFT;
2068	unsigned long last_vpfn = end >> VTD_PAGE_SHIFT;
2069
2070	if (!reserve_iova(&domain->iovad, dma_to_mm_pfn(first_vpfn),
2071			  dma_to_mm_pfn(last_vpfn))) {
2072		printk(KERN_ERR "IOMMU: reserve iova failed\n");
2073		return -ENOMEM;
2074	}
2075
2076	pr_debug("Mapping reserved region %llx-%llx for domain %d\n",
2077		 start, end, domain->id);
2078	/*
2079	 * RMRR range might have overlap with physical memory range,
2080	 * clear it first
2081	 */
2082	dma_pte_clear_range(domain, first_vpfn, last_vpfn);
2083
2084	return domain_pfn_mapping(domain, first_vpfn, first_vpfn,
2085				  last_vpfn - first_vpfn + 1,
2086				  DMA_PTE_READ|DMA_PTE_WRITE);
2087}
2088
2089static int iommu_prepare_identity_map(struct pci_dev *pdev,
2090				      unsigned long long start,
2091				      unsigned long long end)
2092{
2093	struct dmar_domain *domain;
2094	int ret;
2095
2096	domain = get_domain_for_dev(pdev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
2097	if (!domain)
2098		return -ENOMEM;
2099
2100	/* For _hardware_ passthrough, don't bother. But for software
2101	   passthrough, we do it anyway -- it may indicate a memory
2102	   range which is reserved in E820, so which didn't get set
2103	   up to start with in si_domain */
2104	if (domain == si_domain && hw_pass_through) {
2105		printk("Ignoring identity map for HW passthrough device %s [0x%Lx - 0x%Lx]\n",
2106		       pci_name(pdev), start, end);
2107		return 0;
2108	}
2109
2110	printk(KERN_INFO
2111	       "IOMMU: Setting identity map for device %s [0x%Lx - 0x%Lx]\n",
2112	       pci_name(pdev), start, end);
2113	
2114	if (end < start) {
2115		WARN(1, "Your BIOS is broken; RMRR ends before it starts!\n"
2116			"BIOS vendor: %s; Ver: %s; Product Version: %s\n",
2117			dmi_get_system_info(DMI_BIOS_VENDOR),
2118			dmi_get_system_info(DMI_BIOS_VERSION),
2119		     dmi_get_system_info(DMI_PRODUCT_VERSION));
2120		ret = -EIO;
2121		goto error;
2122	}
2123
2124	if (end >> agaw_to_width(domain->agaw)) {
2125		WARN(1, "Your BIOS is broken; RMRR exceeds permitted address width (%d bits)\n"
2126		     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
2127		     agaw_to_width(domain->agaw),
2128		     dmi_get_system_info(DMI_BIOS_VENDOR),
2129		     dmi_get_system_info(DMI_BIOS_VERSION),
2130		     dmi_get_system_info(DMI_PRODUCT_VERSION));
2131		ret = -EIO;
2132		goto error;
2133	}
2134
2135	ret = iommu_domain_identity_map(domain, start, end);
2136	if (ret)
2137		goto error;
2138
2139	/* context entry init */
2140	ret = domain_context_mapping(domain, pdev, CONTEXT_TT_MULTI_LEVEL);
2141	if (ret)
2142		goto error;
2143
2144	return 0;
2145
2146 error:
2147	domain_exit(domain);
2148	return ret;
2149}
2150
2151static inline int iommu_prepare_rmrr_dev(struct dmar_rmrr_unit *rmrr,
2152	struct pci_dev *pdev)
2153{
2154	if (pdev->dev.archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO)
2155		return 0;
2156	return iommu_prepare_identity_map(pdev, rmrr->base_address,
2157		rmrr->end_address);
2158}
2159
2160#ifdef CONFIG_DMAR_FLOPPY_WA
2161static inline void iommu_prepare_isa(void)
2162{
2163	struct pci_dev *pdev;
2164	int ret;
2165
2166	pdev = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
2167	if (!pdev)
2168		return;
2169
2170	printk(KERN_INFO "IOMMU: Prepare 0-16MiB unity mapping for LPC\n");
2171	ret = iommu_prepare_identity_map(pdev, 0, 16*1024*1024 - 1);
2172
2173	if (ret)
2174		printk(KERN_ERR "IOMMU: Failed to create 0-16MiB identity map; "
2175		       "floppy might not work\n");
2176
2177}
2178#else
2179static inline void iommu_prepare_isa(void)
2180{
2181	return;
2182}
2183#endif /* !CONFIG_DMAR_FLPY_WA */
2184
2185static int md_domain_init(struct dmar_domain *domain, int guest_width);
2186
2187static int __init si_domain_work_fn(unsigned long start_pfn,
2188				    unsigned long end_pfn, void *datax)
2189{
2190	int *ret = datax;
2191
2192	*ret = iommu_domain_identity_map(si_domain,
2193					 (uint64_t)start_pfn << PAGE_SHIFT,
2194					 (uint64_t)end_pfn << PAGE_SHIFT);
2195	return *ret;
2196
2197}
2198
2199static int __init si_domain_init(int hw)
2200{
2201	struct dmar_drhd_unit *drhd;
2202	struct intel_iommu *iommu;
2203	int nid, ret = 0;
2204
2205	si_domain = alloc_domain();
2206	if (!si_domain)
2207		return -EFAULT;
2208
2209	pr_debug("Identity mapping domain is domain %d\n", si_domain->id);
2210
2211	for_each_active_iommu(iommu, drhd) {
2212		ret = iommu_attach_domain(si_domain, iommu);
2213		if (ret) {
2214			domain_exit(si_domain);
2215			return -EFAULT;
2216		}
2217	}
2218
2219	if (md_domain_init(si_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
2220		domain_exit(si_domain);
2221		return -EFAULT;
2222	}
2223
2224	si_domain->flags = DOMAIN_FLAG_STATIC_IDENTITY;
2225
2226	if (hw)
2227		return 0;
2228
2229	for_each_online_node(nid) {
2230		work_with_active_regions(nid, si_domain_work_fn, &ret);
2231		if (ret)
2232			return ret;
2233	}
2234
2235	return 0;
2236}
2237
2238static void domain_remove_one_dev_info(struct dmar_domain *domain,
2239					  struct pci_dev *pdev);
2240static int identity_mapping(struct pci_dev *pdev)
2241{
2242	struct device_domain_info *info;
2243
2244	if (likely(!iommu_identity_mapping))
2245		return 0;
2246
2247	info = pdev->dev.archdata.iommu;
2248	if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
2249		return (info->domain == si_domain);
2250
2251	return 0;
2252}
2253
2254static int domain_add_dev_info(struct dmar_domain *domain,
2255			       struct pci_dev *pdev,
2256			       int translation)
2257{
2258	struct device_domain_info *info;
2259	unsigned long flags;
2260	int ret;
2261
2262	info = alloc_devinfo_mem();
2263	if (!info)
2264		return -ENOMEM;
2265
2266	ret = domain_context_mapping(domain, pdev, translation);
2267	if (ret) {
2268		free_devinfo_mem(info);
2269		return ret;
2270	}
2271
2272	info->segment = pci_domain_nr(pdev->bus);
2273	info->bus = pdev->bus->number;
2274	info->devfn = pdev->devfn;
2275	info->dev = pdev;
2276	info->domain = domain;
2277
2278	spin_lock_irqsave(&device_domain_lock, flags);
2279	list_add(&info->link, &domain->devices);
2280	list_add(&info->global, &device_domain_list);
2281	pdev->dev.archdata.iommu = info;
2282	spin_unlock_irqrestore(&device_domain_lock, flags);
2283
2284	return 0;
2285}
2286
2287static int iommu_should_identity_map(struct pci_dev *pdev, int startup)
2288{
2289	if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
2290		return 1;
2291
2292	if ((iommu_identity_mapping & IDENTMAP_GFX) && IS_GFX_DEVICE(pdev))
2293		return 1;
2294
2295	if (!(iommu_identity_mapping & IDENTMAP_ALL))
2296		return 0;
2297
2298	/*
2299	 * We want to start off with all devices in the 1:1 domain, and
2300	 * take them out later if we find they can't access all of memory.
2301	 *
2302	 * However, we can't do this for PCI devices behind bridges,
2303	 * because all PCI devices behind the same bridge will end up
2304	 * with the same source-id on their transactions.
2305	 *
2306	 * Practically speaking, we can't change things around for these
2307	 * devices at run-time, because we can't be sure there'll be no
2308	 * DMA transactions in flight for any of their siblings.
2309	 * 
2310	 * So PCI devices (unless they're on the root bus) as well as
2311	 * their parent PCI-PCI or PCIe-PCI bridges must be left _out_ of
2312	 * the 1:1 domain, just in _case_ one of their siblings turns out
2313	 * not to be able to map all of memory.
2314	 */
2315	if (!pci_is_pcie(pdev)) {
2316		if (!pci_is_root_bus(pdev->bus))
2317			return 0;
2318		if (pdev->class >> 8 == PCI_CLASS_BRIDGE_PCI)
2319			return 0;
2320	} else if (pdev->pcie_type == PCI_EXP_TYPE_PCI_BRIDGE)
2321		return 0;
2322
2323	/* 
2324	 * At boot time, we don't yet know if devices will be 64-bit capable.
2325	 * Assume that they will -- if they turn out not to be, then we can 
2326	 * take them out of the 1:1 domain later.
2327	 */
2328	if (!startup) {
2329		/*
2330		 * If the device's dma_mask is less than the system's memory
2331		 * size then this is not a candidate for identity mapping.
2332		 */
2333		u64 dma_mask = pdev->dma_mask;
2334
2335		if (pdev->dev.coherent_dma_mask &&
2336		    pdev->dev.coherent_dma_mask < dma_mask)
2337			dma_mask = pdev->dev.coherent_dma_mask;
2338
2339		return dma_mask >= dma_get_required_mask(&pdev->dev);
2340	}
2341
2342	return 1;
2343}
2344
2345static int __init iommu_prepare_static_identity_mapping(int hw)
2346{
2347	struct pci_dev *pdev = NULL;
2348	int ret;
2349
2350	ret = si_domain_init(hw);
2351	if (ret)
2352		return -EFAULT;
2353
2354	for_each_pci_dev(pdev) {
2355		/* Skip Host/PCI Bridge devices */
2356		if (IS_BRIDGE_HOST_DEVICE(pdev))
2357			continue;
2358		if (iommu_should_identity_map(pdev, 1)) {
2359			printk(KERN_INFO "IOMMU: %s identity mapping for device %s\n",
2360			       hw ? "hardware" : "software", pci_name(pdev));
2361
2362			ret = domain_add_dev_info(si_domain, pdev,
2363						     hw ? CONTEXT_TT_PASS_THROUGH :
2364						     CONTEXT_TT_MULTI_LEVEL);
2365			if (ret)
2366				return ret;
2367		}
2368	}
2369
2370	return 0;
2371}
2372
2373static int __init init_dmars(void)
2374{
2375	struct dmar_drhd_unit *drhd;
2376	struct dmar_rmrr_unit *rmrr;
2377	struct pci_dev *pdev;
2378	struct intel_iommu *iommu;
2379	int i, ret;
2380
2381	/*
2382	 * for each drhd
2383	 *    allocate root
2384	 *    initialize and program root entry to not present
2385	 * endfor
2386	 */
2387	for_each_drhd_unit(drhd) {
2388		g_num_of_iommus++;
2389		/*
2390		 * lock not needed as this is only incremented in the single
2391		 * threaded kernel __init code path all other access are read
2392		 * only
2393		 */
2394	}
2395
2396	g_iommus = kcalloc(g_num_of_iommus, sizeof(struct intel_iommu *),
2397			GFP_KERNEL);
2398	if (!g_iommus) {
2399		printk(KERN_ERR "Allocating global iommu array failed\n");
2400		ret = -ENOMEM;
2401		goto error;
2402	}
2403
2404	deferred_flush = kzalloc(g_num_of_iommus *
2405		sizeof(struct deferred_flush_tables), GFP_KERNEL);
2406	if (!deferred_flush) {
2407		ret = -ENOMEM;
2408		goto error;
2409	}
2410
2411	for_each_drhd_unit(drhd) {
2412		if (drhd->ignored)
2413			continue;
2414
2415		iommu = drhd->iommu;
2416		g_iommus[iommu->seq_id] = iommu;
2417
2418		ret = iommu_init_domains(iommu);
2419		if (ret)
2420			goto error;
2421
2422		/*
2423		 * TBD:
2424		 * we could share the same root & context tables
2425		 * among all IOMMU's. Need to Split it later.
2426		 */
2427		ret = iommu_alloc_root_entry(iommu);
2428		if (ret) {
2429			printk(KERN_ERR "IOMMU: allocate root entry failed\n");
2430			goto error;
2431		}
2432		if (!ecap_pass_through(iommu->ecap))
2433			hw_pass_through = 0;
2434	}
2435
2436	/*
2437	 * Start from the sane iommu hardware state.
2438	 */
2439	for_each_drhd_unit(drhd) {
2440		if (drhd->ignored)
2441			continue;
2442
2443		iommu = drhd->iommu;
2444
2445		/*
2446		 * If the queued invalidation is already initialized by us
2447		 * (for example, while enabling interrupt-remapping) then
2448		 * we got the things already rolling from a sane state.
2449		 */
2450		if (iommu->qi)
2451			continue;
2452
2453		/*
2454		 * Clear any previous faults.
2455		 */
2456		dmar_fault(-1, iommu);
2457		/*
2458		 * Disable queued invalidation if supported and already enabled
2459		 * before OS handover.
2460		 */
2461		dmar_disable_qi(iommu);
2462	}
2463
2464	for_each_drhd_unit(drhd) {
2465		if (drhd->ignored)
2466			continue;
2467
2468		iommu = drhd->iommu;
2469
2470		if (dmar_enable_qi(iommu)) {
2471			/*
2472			 * Queued Invalidate not enabled, use Register Based
2473			 * Invalidate
2474			 */
2475			iommu->flush.flush_context = __iommu_flush_context;
2476			iommu->flush.flush_iotlb = __iommu_flush_iotlb;
2477			printk(KERN_INFO "IOMMU %d 0x%Lx: using Register based "
2478			       "invalidation\n",
2479				iommu->seq_id,
2480			       (unsigned long long)drhd->reg_base_addr);
2481		} else {
2482			iommu->flush.flush_context = qi_flush_context;
2483			iommu->flush.flush_iotlb = qi_flush_iotlb;
2484			printk(KERN_INFO "IOMMU %d 0x%Lx: using Queued "
2485			       "invalidation\n",
2486				iommu->seq_id,
2487			       (unsigned long long)drhd->reg_base_addr);
2488		}
2489	}
2490
2491	if (iommu_pass_through)
2492		iommu_identity_mapping |= IDENTMAP_ALL;
2493
2494#ifdef CONFIG_DMAR_BROKEN_GFX_WA
2495	iommu_identity_mapping |= IDENTMAP_GFX;
2496#endif
2497
2498	check_tylersburg_isoch();
2499
2500	/*
2501	 * If pass through is not set or not enabled, setup context entries for
2502	 * identity mappings for rmrr, gfx, and isa and may fall back to static
2503	 * identity mapping if iommu_identity_mapping is set.
2504	 */
2505	if (iommu_identity_mapping) {
2506		ret = iommu_prepare_static_identity_mapping(hw_pass_through);
2507		if (ret) {
2508			printk(KERN_CRIT "Failed to setup IOMMU pass-through\n");
2509			goto error;
2510		}
2511	}
2512	/*
2513	 * For each rmrr
2514	 *   for each dev attached to rmrr
2515	 *   do
2516	 *     locate drhd for dev, alloc domain for dev
2517	 *     allocate free domain
2518	 *     allocate page table entries for rmrr
2519	 *     if context not allocated for bus
2520	 *           allocate and init context
2521	 *           set present in root table for this bus
2522	 *     init context with domain, translation etc
2523	 *    endfor
2524	 * endfor
2525	 */
2526	printk(KERN_INFO "IOMMU: Setting RMRR:\n");
2527	for_each_rmrr_units(rmrr) {
2528		for (i = 0; i < rmrr->devices_cnt; i++) {
2529			pdev = rmrr->devices[i];
2530			/*
2531			 * some BIOS lists non-exist devices in DMAR
2532			 * table.
2533			 */
2534			if (!pdev)
2535				continue;
2536			ret = iommu_prepare_rmrr_dev(rmrr, pdev);
2537			if (ret)
2538				printk(KERN_ERR
2539				       "IOMMU: mapping reserved region failed\n");
2540		}
2541	}
2542
2543	iommu_prepare_isa();
2544
2545	/*
2546	 * for each drhd
2547	 *   enable fault log
2548	 *   global invalidate context cache
2549	 *   global invalidate iotlb
2550	 *   enable translation
2551	 */
2552	for_each_drhd_unit(drhd) {
2553		if (drhd->ignored) {
2554			/*
2555			 * we always have to disable PMRs or DMA may fail on
2556			 * this device
2557			 */
2558			if (force_on)
2559				iommu_disable_protect_mem_regions(drhd->iommu);
2560			continue;
2561		}
2562		iommu = drhd->iommu;
2563
2564		iommu_flush_write_buffer(iommu);
2565
2566		ret = dmar_set_interrupt(iommu);
2567		if (ret)
2568			goto error;
2569
2570		iommu_set_root_entry(iommu);
2571
2572		iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
2573		iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
2574
2575		ret = iommu_enable_translation(iommu);
2576		if (ret)
2577			goto error;
2578
2579		iommu_disable_protect_mem_regions(iommu);
2580	}
2581
2582	return 0;
2583error:
2584	for_each_drhd_unit(drhd) {
2585		if (drhd->ignored)
2586			continue;
2587		iommu = drhd->iommu;
2588		free_iommu(iommu);
2589	}
2590	kfree(g_iommus);
2591	return ret;
2592}
2593
2594/* This takes a number of _MM_ pages, not VTD pages */
2595static struct iova *intel_alloc_iova(struct device *dev,
2596				     struct dmar_domain *domain,
2597				     unsigned long nrpages, uint64_t dma_mask)
2598{
2599	struct pci_dev *pdev = to_pci_dev(dev);
2600	struct iova *iova = NULL;
2601
2602	/* Restrict dma_mask to the width that the iommu can handle */
2603	dma_mask = min_t(uint64_t, DOMAIN_MAX_ADDR(domain->gaw), dma_mask);
2604
2605	if (!dmar_forcedac && dma_mask > DMA_BIT_MASK(32)) {
2606		/*
2607		 * First try to allocate an io virtual address in
2608		 * DMA_BIT_MASK(32) and if that fails then try allocating
2609		 * from higher range
2610		 */
2611		iova = alloc_iova(&domain->iovad, nrpages,
2612				  IOVA_PFN(DMA_BIT_MASK(32)), 1);
2613		if (iova)
2614			return iova;
2615	}
2616	iova = alloc_iova(&domain->iovad, nrpages, IOVA_PFN(dma_mask), 1);
2617	if (unlikely(!iova)) {
2618		printk(KERN_ERR "Allocating %ld-page iova for %s failed",
2619		       nrpages, pci_name(pdev));
2620		return NULL;
2621	}
2622
2623	return iova;
2624}
2625
2626static struct dmar_domain *__get_valid_domain_for_dev(struct pci_dev *pdev)
2627{
2628	struct dmar_domain *domain;
2629	int ret;
2630
2631	domain = get_domain_for_dev(pdev,
2632			DEFAULT_DOMAIN_ADDRESS_WIDTH);
2633	if (!domain) {
2634		printk(KERN_ERR
2635			"Allocating domain for %s failed", pci_name(pdev));
2636		return NULL;
2637	}
2638
2639	/* make sure context mapping is ok */
2640	if (unlikely(!domain_context_mapped(pdev))) {
2641		ret = domain_context_mapping(domain, pdev,
2642					     CONTEXT_TT_MULTI_LEVEL);
2643		if (ret) {
2644			printk(KERN_ERR
2645				"Domain context map for %s failed",
2646				pci_name(pdev));
2647			return NULL;
2648		}
2649	}
2650
2651	return domain;
2652}
2653
2654static inline struct dmar_domain *get_valid_domain_for_dev(struct pci_dev *dev)
2655{
2656	struct device_domain_info *info;
2657
2658	/* No lock here, assumes no domain exit in normal case */
2659	info = dev->dev.archdata.iommu;
2660	if (likely(info))
2661		return info->domain;
2662
2663	return __get_valid_domain_for_dev(dev);
2664}
2665
2666static int iommu_dummy(struct pci_dev *pdev)
2667{
2668	return pdev->dev.archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO;
2669}
2670
2671/* Check if the pdev needs to go through non-identity map and unmap process.*/
2672static int iommu_no_mapping(struct device *dev)
2673{
2674	struct pci_dev *pdev;
2675	int found;
2676
2677	if (unlikely(dev->bus != &pci_bus_type))
2678		return 1;
2679
2680	pdev = to_pci_dev(dev);
2681	if (iommu_dummy(pdev))
2682		return 1;
2683
2684	if (!iommu_identity_mapping)
2685		return 0;
2686
2687	found = identity_mapping(pdev);
2688	if (found) {
2689		if (iommu_should_identity_map(pdev, 0))
2690			return 1;
2691		else {
2692			/*
2693			 * 32 bit DMA is removed from si_domain and fall back
2694			 * to non-identity mapping.
2695			 */
2696			domain_remove_one_dev_info(si_domain, pdev);
2697			printk(KERN_INFO "32bit %s uses non-identity mapping\n",
2698			       pci_name(pdev));
2699			return 0;
2700		}
2701	} else {
2702		/*
2703		 * In case of a detached 64 bit DMA device from vm, the device
2704		 * is put into si_domain for identity mapping.
2705		 */
2706		if (iommu_should_identity_map(pdev, 0)) {
2707			int ret;
2708			ret = domain_add_dev_info(si_domain, pdev,
2709						  hw_pass_through ?
2710						  CONTEXT_TT_PASS_THROUGH :
2711						  CONTEXT_TT_MULTI_LEVEL);
2712			if (!ret) {
2713				printk(KERN_INFO "64bit %s uses identity mapping\n",
2714				       pci_name(pdev));
2715				return 1;
2716			}
2717		}
2718	}
2719
2720	return 0;
2721}
2722
2723static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr,
2724				     size_t size, int dir, u64 dma_mask)
2725{
2726	struct pci_dev *pdev = to_pci_dev(hwdev);
2727	struct dmar_domain *domain;
2728	phys_addr_t start_paddr;
2729	struct iova *iova;
2730	int prot = 0;
2731	int ret;
2732	struct intel_iommu *iommu;
2733	unsigned long paddr_pfn = paddr >> PAGE_SHIFT;
2734
2735	BUG_ON(dir == DMA_NONE);
2736
2737	if (iommu_no_mapping(hwdev))
2738		return paddr;
2739
2740	domain = get_valid_domain_for_dev(pdev);
2741	if (!domain)
2742		return 0;
2743
2744	iommu = domain_get_iommu(domain);
2745	size = aligned_nrpages(paddr, size);
2746
2747	iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size), dma_mask);
2748	if (!iova)
2749		goto error;
2750
2751	/*
2752	 * Check if DMAR supports zero-length reads on write only
2753	 * mappings..
2754	 */
2755	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL || \
2756			!cap_zlr(iommu->cap))
2757		prot |= DMA_PTE_READ;
2758	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
2759		prot |= DMA_PTE_WRITE;
2760	/*
2761	 * paddr - (paddr + size) might be partial page, we should map the whole
2762	 * page.  Note: if two part of one page are separately mapped, we
2763	 * might have two guest_addr mapping to the same host paddr, but this
2764	 * is not a big problem
2765	 */
2766	ret = domain_pfn_mapping(domain, mm_to_dma_pfn(iova->pfn_lo),
2767				 mm_to_dma_pfn(paddr_pfn), size, prot);
2768	if (ret)
2769		goto error;
2770
2771	/* it's a non-present to present mapping. Only flush if caching mode */
2772	if (cap_caching_mode(iommu->cap))
2773		iommu_flush_iotlb_psi(iommu, domain->id, mm_to_dma_pfn(iova->pfn_lo), size, 1);
2774	else
2775		iommu_flush_write_buffer(iommu);
2776
2777	start_paddr = (phys_addr_t)iova->pfn_lo << PAGE_SHIFT;
2778	start_paddr += paddr & ~PAGE_MASK;
2779	return start_paddr;
2780
2781error:
2782	if (iova)
2783		__free_iova(&domain->iovad, iova);
2784	printk(KERN_ERR"Device %s request: %zx@%llx dir %d --- failed\n",
2785		pci_name(pdev), size, (unsigned long long)paddr, dir);
2786	return 0;
2787}
2788
2789static dma_addr_t intel_map_page(struct device *dev, struct page *page,
2790				 unsigned long offset, size_t size,
2791				 enum dma_data_direction dir,
2792				 struct dma_attrs *attrs)
2793{
2794	return __intel_map_single(dev, page_to_phys(page) + offset, size,
2795				  dir, to_pci_dev(dev)->dma_mask);
2796}
2797
2798static void flush_unmaps(void)
2799{
2800	int i, j;
2801
2802	timer_on = 0;
2803
2804	/* just flush them all */
2805	for (i = 0; i < g_num_of_iommus; i++) {
2806		struct intel_iommu *iommu = g_iommus[i];
2807		if (!iommu)
2808			continue;
2809
2810		if (!deferred_flush[i].next)
2811			continue;
2812
2813		/* In caching mode, global flushes turn emulation expensive */
2814		if (!cap_caching_mode(iommu->cap))
2815			iommu->flush.flush_iotlb(iommu, 0, 0, 0,
2816					 DMA_TLB_GLOBAL_FLUSH);
2817		for (j = 0; j < deferred_flush[i].next; j++) {
2818			unsigned long mask;
2819			struct iova *iova = deferred_flush[i].iova[j];
2820			struct dmar_domain *domain = deferred_flush[i].domain[j];
2821
2822			/* On real hardware multiple invalidations are expensive */
2823			if (cap_caching_mode(iommu->cap))
2824				iommu_flush_iotlb_psi(iommu, domain->id,
2825				iova->pfn_lo, iova->pfn_hi - iova->pfn_lo + 1, 0);
2826			else {
2827				mask = ilog2(mm_to_dma_pfn(iova->pfn_hi - iova->pfn_lo + 1));
2828				iommu_flush_dev_iotlb(deferred_flush[i].domain[j],
2829						(uint64_t)iova->pfn_lo << PAGE_SHIFT, mask);
2830			}
2831			__free_iova(&deferred_flush[i].domain[j]->iovad, iova);
2832		}
2833		deferred_flush[i].next = 0;
2834	}
2835
2836	list_size = 0;
2837}
2838
2839static void flush_unmaps_timeout(unsigned long data)
2840{
2841	unsigned long flags;
2842
2843	spin_lock_irqsave(&async_umap_flush_lock, flags);
2844	flush_unmaps();
2845	spin_unlock_irqrestore(&async_umap_flush_lock, flags);
2846}
2847
2848static void add_unmap(struct dmar_domain *dom, struct iova *iova)
2849{
2850	unsigned long flags;
2851	int next, iommu_id;
2852	struct intel_iommu *iommu;
2853
2854	spin_lock_irqsave(&async_umap_flush_lock, flags);
2855	if (list_size == HIGH_WATER_MARK)
2856		flush_unmaps();
2857
2858	iommu = domain_get_iommu(dom);
2859	iommu_id = iommu->seq_id;
2860
2861	next = deferred_flush[iommu_id].next;
2862	deferred_flush[iommu_id].domain[next] = dom;
2863	deferred_flush[iommu_id].iova[next] = iova;
2864	deferred_flush[iommu_id].next++;
2865
2866	if (!timer_on) {
2867		mod_timer(&unmap_timer, jiffies + msecs_to_jiffies(10));
2868		timer_on = 1;
2869	}
2870	list_size++;
2871	spin_unlock_irqrestore(&async_umap_flush_lock, flags);
2872}
2873
2874static void intel_unmap_page(struct device *dev, dma_addr_t dev_addr,
2875			     size_t size, enum dma_data_direction dir,
2876			     struct dma_attrs *attrs)
2877{
2878	struct pci_dev *pdev = to_pci_dev(dev);
2879	struct dmar_domain *domain;
2880	unsigned long start_pfn, last_pfn;
2881	struct iova *iova;
2882	struct intel_iommu *iommu;
2883
2884	if (iommu_no_mapping(dev))
2885		return;
2886
2887	domain = find_domain(pdev);
2888	BUG_ON(!domain);
2889
2890	iommu = domain_get_iommu(domain);
2891
2892	iova = find_iova(&domain->iovad, IOVA_PFN(dev_addr));
2893	if (WARN_ONCE(!iova, "Driver unmaps unmatched page at PFN %llx\n",
2894		      (unsigned long long)dev_addr))
2895		return;
2896
2897	start_pfn = mm_to_dma_pfn(iova->pfn_lo);
2898	last_pfn = mm_to_dma_pfn(iova->pfn_hi + 1) - 1;
2899
2900	pr_debug("Device %s unmapping: pfn %lx-%lx\n",
2901		 pci_name(pdev), start_pfn, last_pfn);
2902
2903	/*  clear the whole page */
2904	dma_pte_clear_range(domain, start_pfn, last_pfn);
2905
2906	/* free page tables */
2907	dma_pte_free_pagetable(domain, start_pfn, last_pfn);
2908
2909	if (intel_iommu_strict) {
2910		iommu_flush_iotlb_psi(iommu, domain->id, start_pfn,
2911				      last_pfn - start_pfn + 1, 0);
2912		/* free iova */
2913		__free_iova(&domain->iovad, iova);
2914	} else {
2915		add_unmap(domain, iova);
2916		/*
2917		 * queue up the release of the unmap to save the 1/6th of the
2918		 * cpu used up by the iotlb flush operation...
2919		 */
2920	}
2921}
2922
2923static void *intel_alloc_coherent(struct device *hwdev, size_t size,
2924				  dma_addr_t *dma_handle, gfp_t flags)
2925{
2926	void *vaddr;
2927	int order;
2928
2929	size = PAGE_ALIGN(size);
2930	order = get_order(size);
2931
2932	if (!iommu_no_mapping(hwdev))
2933		flags &= ~(GFP_DMA | GFP_DMA32);
2934	else if (hwdev->coherent_dma_mask < dma_get_required_mask(hwdev)) {
2935		if (hwdev->coherent_dma_mask < DMA_BIT_MASK(32))
2936			flags |= GFP_DMA;
2937		else
2938			flags |= GFP_DMA32;
2939	}
2940
2941	vaddr = (void *)__get_free_pages(flags, order);
2942	if (!vaddr)
2943		return NULL;
2944	memset(vaddr, 0, size);
2945
2946	*dma_handle = __intel_map_single(hwdev, virt_to_bus(vaddr), size,
2947					 DMA_BIDIRECTIONAL,
2948					 hwdev->coherent_dma_mask);
2949	if (*dma_handle)
2950		return vaddr;
2951	free_pages((unsigned long)vaddr, order);
2952	return NULL;
2953}
2954
2955static void intel_free_coherent(struct device *hwdev, size_t size, void *vaddr,
2956				dma_addr_t dma_handle)
2957{
2958	int order;
2959
2960	size = PAGE_ALIGN(size);
2961	order = get_order(size);
2962
2963	intel_unmap_page(hwdev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);
2964	free_pages((unsigned long)vaddr, order);
2965}
2966
2967static void intel_unmap_sg(struct device *hwdev, struct scatterlist *sglist,
2968			   int nelems, enum dma_data_direction dir,
2969			   struct dma_attrs *attrs)
2970{
2971	struct pci_dev *pdev = to_pci_dev(hwdev);
2972	struct dmar_domain *domain;
2973	unsigned long start_pfn, last_pfn;
2974	struct iova *iova;
2975	struct intel_iommu *iommu;
2976
2977	if (iommu_no_mapping(hwdev))
2978		return;
2979
2980	domain = find_domain(pdev);
2981	BUG_ON(!domain);
2982
2983	iommu = domain_get_iommu(domain);
2984
2985	iova = find_iova(&domain->iovad, IOVA_PFN(sglist[0].dma_address));
2986	if (WARN_ONCE(!iova, "Driver unmaps unmatched sglist at PFN %llx\n",
2987		      (unsigned long long)sglist[0].dma_address))
2988		return;
2989
2990	start_pfn = mm_to_dma_pfn(iova->pfn_lo);
2991	last_pfn = mm_to_dma_pfn(iova->pfn_hi + 1) - 1;
2992
2993	/*  clear the whole page */
2994	dma_pte_clear_range(domain, start_pfn, last_pfn);
2995
2996	/* free page tables */
2997	dma_pte_free_pagetable(domain, start_pfn, last_pfn);
2998
2999	if (intel_iommu_strict) {
3000		iommu_flush_iotlb_psi(iommu, domain->id, start_pfn,
3001				      last_pfn - start_pfn + 1, 0);
3002		/* free iova */
3003		__free_iova(&domain->iovad, iova);
3004	} else {
3005		add_unmap(domain, iova);
3006		/*
3007		 * queue up the release of the unmap to save the 1/6th of the
3008		 * cpu used up by the iotlb flush operation...
3009		 */
3010	}
3011}
3012
3013static int intel_nontranslate_map_sg(struct device *hddev,
3014	struct scatterlist *sglist, int nelems, int dir)
3015{
3016	int i;
3017	struct scatterlist *sg;
3018
3019	for_each_sg(sglist, sg, nelems, i) {
3020		BUG_ON(!sg_page(sg));
3021		sg->dma_address = page_to_phys(sg_page(sg)) + sg->offset;
3022		sg->dma_length = sg->length;
3023	}
3024	return nelems;
3025}
3026
3027static int intel_map_sg(struct device *hwdev, struct scatterlist *sglist, int nelems,
3028			enum dma_data_direction dir, struct dma_attrs *attrs)
3029{
3030	int i;
3031	struct pci_dev *pdev = to_pci_dev(hwdev);
3032	struct dmar_domain *domain;
3033	size_t size = 0;
3034	int prot = 0;
3035	struct iova *iova = NULL;
3036	int ret;
3037	struct scatterlist *sg;
3038	unsigned long start_vpfn;
3039	struct intel_iommu *iommu;
3040
3041	BUG_ON(dir == DMA_NONE);
3042	if (iommu_no_mapping(hwdev))
3043		return intel_nontranslate_map_sg(hwdev, sglist, nelems, dir);
3044
3045	domain = get_valid_domain_for_dev(pdev);
3046	if (!domain)
3047		return 0;
3048
3049	iommu = domain_get_iommu(domain);
3050
3051	for_each_sg(sglist, sg, nelems, i)
3052		size += aligned_nrpages(sg->offset, sg->length);
3053
3054	iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),
3055				pdev->dma_mask);
3056	if (!iova) {
3057		sglist->dma_length = 0;
3058		return 0;
3059	}
3060
3061	/*
3062	 * Check if DMAR supports zero-length reads on write only
3063	 * mappings..
3064	 */
3065	if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL || \
3066			!cap_zlr(iommu->cap))
3067		prot |= DMA_PTE_READ;
3068	if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
3069		prot |= DMA_PTE_WRITE;
3070
3071	start_vpfn = mm_to_dma_pfn(iova->pfn_lo);
3072
3073	ret = domain_sg_mapping(domain, start_vpfn, sglist, size, prot);
3074	if (unlikely(ret)) {
3075		/*  clear the page */
3076		dma_pte_clear_range(domain, start_vpfn,
3077				    start_vpfn + size - 1);
3078		/* free page tables */
3079		dma_pte_free_pagetable(domain, start_vpfn,
3080				       start_vpfn + size - 1);
3081		/* free iova */
3082		__free_iova(&domain->iovad, iova);
3083		return 0;
3084	}
3085
3086	/* it's a non-present to present mapping. Only flush if caching mode */
3087	if (cap_caching_mode(iommu->cap))
3088		iommu_flush_iotlb_psi(iommu, domain->id, start_vpfn, size, 1);
3089	else
3090		iommu_flush_write_buffer(iommu);
3091
3092	return nelems;
3093}
3094
3095static int intel_mapping_error(struct device *dev, dma_addr_t dma_addr)
3096{
3097	return !dma_addr;
3098}
3099
3100struct dma_map_ops intel_dma_ops = {
3101	.alloc_coherent = intel_alloc_coherent,
3102	.free_coherent = intel_free_coherent,
3103	.map_sg = intel_map_sg,
3104	.unmap_sg = intel_unmap_sg,
3105	.map_page = intel_map_page,
3106	.unmap_page = intel_unmap_page,
3107	.mapping_error = intel_mapping_error,
3108};
3109
3110static inline int iommu_domain_cache_init(void)
3111{
3112	int ret = 0;
3113
3114	iommu_domain_cache = kmem_cache_create("iommu_domain",
3115					 sizeof(struct dmar_domain),
3116					 0,
3117					 SLAB_HWCACHE_ALIGN,
3118
3119					 NULL);
3120	if (!iommu_domain_cache) {
3121		printk(KERN_ERR "Couldn't create iommu_domain cache\n");
3122		ret = -ENOMEM;
3123	}
3124
3125	return ret;
3126}
3127
3128static inline int iommu_devinfo_cache_init(void)
3129{
3130	int ret = 0;
3131
3132	iommu_devinfo_cache = kmem_cache_create("iommu_devinfo",
3133					 sizeof(struct device_domain_info),
3134					 0,
3135					 SLAB_HWCACHE_ALIGN,
3136					 NULL);
3137	if (!iommu_devinfo_cache) {
3138		printk(KERN_ERR "Couldn't create devinfo cache\n");
3139		ret = -ENOMEM;
3140	}
3141
3142	return ret;
3143}
3144
3145static inline int iommu_iova_cache_init(void)
3146{
3147	int ret = 0;
3148
3149	iommu_iova_cache = kmem_cache_create("iommu_iova",
3150					 sizeof(struct iova),
3151					 0,
3152					 SLAB_HWCACHE_ALIGN,
3153					 NULL);
3154	if (!iommu_iova_cache) {
3155		printk(KERN_ERR "Couldn't create iova cache\n");
3156		ret = -ENOMEM;
3157	}
3158
3159	return ret;
3160}
3161
3162static int __init iommu_init_mempool(void)
3163{
3164	int ret;
3165	ret = iommu_iova_cache_init();
3166	if (ret)
3167		return ret;
3168
3169	ret = iommu_domain_cache_init();
3170	if (ret)
3171		goto domain_error;
3172
3173	ret = iommu_devinfo_cache_init();
3174	if (!ret)
3175		return ret;
3176
3177	kmem_cache_destroy(iommu_domain_cache);
3178domain_error:
3179	kmem_cache_destroy(iommu_iova_cache);
3180
3181	return -ENOMEM;
3182}
3183
3184static void __init iommu_exit_mempool(void)
3185{
3186	kmem_cache_destroy(iommu_devinfo_cache);
3187	kmem_cache_destroy(iommu_domain_cache);
3188	kmem_cache_destroy(iommu_iova_cache);
3189
3190}
3191
3192static void quirk_ioat_snb_local_iommu(struct pci_dev *pdev)
3193{
3194	struct dmar_drhd_unit *drhd;
3195	u32 vtbar;
3196	int rc;
3197
3198	/* We know that this device on this chipset has its own IOMMU.
3199	 * If we find it under a different IOMMU, then the BIOS is lying
3200	 * to us. Hope that the IOMMU for this device is actually
3201	 * disabled, and it needs no translation...
3202	 */
3203	rc = pci_bus_read_config_dword(pdev->bus, PCI_DEVFN(0, 0), 0xb0, &vtbar);
3204	if (rc) {
3205		/* "can't" happen */
3206		dev_info(&pdev->dev, "failed to run vt-d quirk\n");
3207		return;
3208	}
3209	vtbar &= 0xffff0000;
3210
3211	/* we know that the this iommu should be at offset 0xa000 from vtbar */
3212	drhd = dmar_find_matched_drhd_unit(pdev);
3213	if (WARN_TAINT_ONCE(!drhd || drhd->reg_base_addr - vtbar != 0xa000,
3214			    TAINT_FIRMWARE_WORKAROUND,
3215			    "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n"))
3216		pdev->dev.archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
3217}
3218DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SNB, quirk_ioat_snb_local_iommu);
3219
3220static void __init init_no_remapping_devices(void)
3221{
3222	struct dmar_drhd_unit *drhd;
3223
3224	for_each_drhd_unit(drhd) {
3225		if (!drhd->include_all) {
3226			int i;
3227			for (i = 0; i < drhd->devices_cnt; i++)
3228				if (drhd->devices[i] != NULL)
3229					break;
3230			/* ignore DMAR unit if no pci devices exist */
3231			if (i == drhd->devices_cnt)
3232				drhd->ignored = 1;
3233		}
3234	}
3235
3236	for_each_drhd_unit(drhd) {
3237		int i;
3238		if (drhd->ignored || drhd->include_all)
3239			continue;
3240
3241		for (i = 0; i < drhd->devices_cnt; i++)
3242			if (drhd->devices[i] &&
3243			    !IS_GFX_DEVICE(drhd->devices[i]))
3244				break;
3245
3246		if (i < drhd->devices_cnt)
3247			continue;
3248
3249		/* This IOMMU has *only* gfx devices. Either bypass it or
3250		   set the gfx_mapped flag, as appropriate */
3251		if (dmar_map_gfx) {
3252			intel_iommu_gfx_mapped = 1;
3253		} else {
3254			drhd->ignored = 1;
3255			for (i = 0; i < drhd->devices_cnt; i++) {
3256				if (!drhd->devices[i])
3257					continue;
3258				drhd->devices[i]->dev.archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
3259			}
3260		}
3261	}
3262}
3263
3264#ifdef CONFIG_SUSPEND
3265static int init_iommu_hw(void)
3266{
3267	struct dmar_drhd_unit *drhd;
3268	struct intel_iommu *iommu = NULL;
3269
3270	for_each_active_iommu(iommu, drhd)
3271		if (iommu->qi)
3272			dmar_reenable_qi(iommu);
3273
3274	for_each_iommu(iommu, drhd) {
3275		if (drhd->ignored) {
3276			/*
3277			 * we always have to disable PMRs or DMA may fail on
3278			 * this device
3279			 */
3280			if (force_on)
3281				iommu_disable_protect_mem_regions(iommu);
3282			continue;
3283		}
3284	
3285		iommu_flush_write_buffer(iommu);
3286
3287		iommu_set_root_entry(iommu);
3288
3289		iommu->flush.flush_context(iommu, 0, 0, 0,
3290					   DMA_CCMD_GLOBAL_INVL);
3291		iommu->flush.flush_iotlb(iommu, 0, 0, 0,
3292					 DMA_TLB_GLOBAL_FLUSH);
3293		if (iommu_enable_translation(iommu))
3294			return 1;
3295		iommu_disable_protect_mem_regions(iommu);
3296	}
3297
3298	return 0;
3299}
3300
3301static void iommu_flush_all(void)
3302{
3303	struct dmar_drhd_unit *drhd;
3304	struct intel_iommu *iommu;
3305
3306	for_each_active_iommu(iommu, drhd) {
3307		iommu->flush.flush_context(iommu, 0, 0, 0,
3308					   DMA_CCMD_GLOBAL_INVL);
3309		iommu->flush.flush_iotlb(iommu, 0, 0, 0,
3310					 DMA_TLB_GLOBAL_FLUSH);
3311	}
3312}
3313
3314static int iommu_suspend(void)
3315{
3316	struct dmar_drhd_unit *drhd;
3317	struct intel_iommu *iommu = NULL;
3318	unsigned long flag;
3319
3320	for_each_active_iommu(iommu, drhd) {
3321		iommu->iommu_state = kzalloc(sizeof(u32) * MAX_SR_DMAR_REGS,
3322						 GFP_ATOMIC);
3323		if (!iommu->iommu_state)
3324			goto nomem;
3325	}
3326
3327	iommu_flush_all();
3328
3329	for_each_active_iommu(iommu, drhd) {
3330		iommu_disable_translation(iommu);
3331
3332		spin_lock_irqsave(&iommu->register_lock, flag);
3333
3334		iommu->iommu_state[SR_DMAR_FECTL_REG] =
3335			readl(iommu->reg + DMAR_FECTL_REG);
3336		iommu->iommu_state[SR_DMAR_FEDATA_REG] =
3337			readl(iommu->reg + DMAR_FEDATA_REG);
3338		iommu->iommu_state[SR_DMAR_FEADDR_REG] =
3339			readl(iommu->reg + DMAR_FEADDR_REG);
3340		iommu->iommu_state[SR_DMAR_FEUADDR_REG] =
3341			readl(iommu->reg + DMAR_FEUADDR_REG);
3342
3343		spin_unlock_irqrestore(&iommu->register_lock, flag);
3344	}
3345	return 0;
3346
3347nomem:
3348	for_each_active_iommu(iommu, drhd)
3349		kfree(iommu->iommu_state);
3350
3351	return -ENOMEM;
3352}
3353
3354static void iommu_resume(void)
3355{
3356	struct dmar_drhd_unit *drhd;
3357	struct intel_iommu *iommu = NULL;
3358	unsigned long flag;
3359
3360	if (init_iommu_hw()) {
3361		if (force_on)
3362			panic("tboot: IOMMU setup failed, DMAR can not resume!\n");
3363		else
3364			WARN(1, "IOMMU setup failed, DMAR can not resume!\n");
3365		return;
3366	}
3367
3368	for_each_active_iommu(iommu, drhd) {
3369
3370		spin_lock_irqsave(&iommu->register_lock, flag);
3371
3372		writel(iommu->iommu_state[SR_DMAR_FECTL_REG],
3373			iommu->reg + DMAR_FECTL_REG);
3374		writel(iommu->iommu_state[SR_DMAR_FEDATA_REG],
3375			iommu->reg + DMAR_FEDATA_REG);
3376		writel(iommu->iommu_state[SR_DMAR_FEADDR_REG],
3377			iommu->reg + DMAR_FEADDR_REG);
3378		writel(iommu->iommu_state[SR_DMAR_FEUADDR_REG],
3379			iommu->reg + DMAR_FEUADDR_REG);
3380
3381		spin_unlock_irqrestore(&iommu->register_lock, flag);
3382	}
3383
3384	for_each_active_iommu(iommu, drhd)
3385		kfree(iommu->iommu_state);
3386}
3387
3388static struct syscore_ops iommu_syscore_ops = {
3389	.resume		= iommu_resume,
3390	.suspend	= iommu_suspend,
3391};
3392
3393static void __init init_iommu_pm_ops(void)
3394{
3395	register_syscore_ops(&iommu_syscore_ops);
3396}
3397
3398#else
3399static inline void init_iommu_pm_ops(void) {}
3400#endif	/* CONFIG_PM */
3401
3402/*
3403 * Here we only respond to action of unbound device from driver.
3404 *
3405 * Added device is not attached to its DMAR domain here yet. That will happen
3406 * when mapping the device to iova.
3407 */
3408static int device_notifier(struct notifier_block *nb,
3409				  unsigned long action, void *data)
3410{
3411	struct device *dev = data;
3412	struct pci_dev *pdev = to_pci_dev(dev);
3413	struct dmar_domain *domain;
3414
3415	if (iommu_no_mapping(dev))
3416		return 0;
3417
3418	domain = find_domain(pdev);
3419	if (!domain)
3420		return 0;
3421
3422	if (action == BUS_NOTIFY_UNBOUND_DRIVER && !iommu_pass_through) {
3423		domain_remove_one_dev_info(domain, pdev);
3424
3425		if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&
3426		    !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) &&
3427		    list_empty(&domain->devices))
3428			domain_exit(domain);
3429	}
3430
3431	return 0;
3432}
3433
3434static struct notifier_block device_nb = {
3435	.notifier_call = device_notifier,
3436};
3437
3438int __init intel_iommu_init(void)
3439{
3440	int ret = 0;
3441
3442	/* VT-d is required for a TXT/tboot launch, so enforce that */
3443	force_on = tboot_force_iommu();
3444
3445	if (dmar_table_init()) {
3446		if (force_on)
3447			panic("tboot: Failed to initialize DMAR table\n");
3448		return 	-ENODEV;
3449	}
3450
3451	if (dmar_dev_scope_init()) {
3452		if (force_on)
3453			panic("tboot: Failed to initialize DMAR device scope\n");
3454		return 	-ENODEV;
3455	}
3456
3457	/*
3458	 * Check the need for DMA-remapping initialization now.
3459	 * Above initialization will also be used by Interrupt-remapping.
3460	 */
3461	if (no_iommu || dmar_disabled)
3462		return -ENODEV;
3463
3464	if (iommu_init_mempool()) {
3465		if (force_on)
3466			panic("tboot: Failed to initialize iommu memory\n");
3467		return 	-ENODEV;
3468	}
3469
3470	if (dmar_init_reserved_ranges()) {
3471		if (force_on)
3472			panic("tboot: Failed to reserve iommu ranges\n");
3473		return 	-ENODEV;
3474	}
3475
3476	init_no_remapping_devices();
3477
3478	ret = init_dmars();
3479	if (ret) {
3480		if (force_on)
3481			panic("tboot: Failed to initialize DMARs\n");
3482		printk(KERN_ERR "IOMMU: dmar init failed\n");
3483		put_iova_domain(&reserved_iova_list);
3484		iommu_exit_mempool();
3485		return ret;
3486	}
3487	printk(KERN_INFO
3488	"PCI-DMA: Intel(R) Virtualization Technology for Directed I/O\n");
3489
3490	init_timer(&unmap_timer);
3491#ifdef CONFIG_SWIOTLB
3492	swiotlb = 0;
3493#endif
3494	dma_ops = &intel_dma_ops;
3495
3496	init_iommu_pm_ops();
3497
3498	register_iommu(&intel_iommu_ops);
3499
3500	bus_register_notifier(&pci_bus_type, &device_nb);
3501
3502	return 0;
3503}
3504
3505static void iommu_detach_dependent_devices(struct intel_iommu *iommu,
3506					   struct pci_dev *pdev)
3507{
3508	struct pci_dev *tmp, *parent;
3509
3510	if (!iommu || !pdev)
3511		return;
3512
3513	/* dependent device detach */
3514	tmp = pci_find_upstream_pcie_bridge(pdev);
3515	/* Secondary interface's bus number and devfn 0 */
3516	if (tmp) {
3517		parent = pdev->bus->self;
3518		while (parent != tmp) {
3519			iommu_detach_dev(iommu, parent->bus->number,
3520					 parent->devfn);
3521			parent = parent->bus->self;
3522		}
3523		if (pci_is_pcie(tmp)) /* this is a PCIe-to-PCI bridge */
3524			iommu_detach_dev(iommu,
3525				tmp->subordinate->number, 0);
3526		else /* this is a legacy PCI bridge */
3527			iommu_detach_dev(iommu, tmp->bus->number,
3528					 tmp->devfn);
3529	}
3530}
3531
3532static void domain_remove_one_dev_info(struct dmar_domain *domain,
3533					  struct pci_dev *pdev)
3534{
3535	struct device_domain_info *info;
3536	struct intel_iommu *iommu;
3537	unsigned long flags;
3538	int found = 0;
3539	struct list_head *entry, *tmp;
3540
3541	iommu = device_to_iommu(pci_domain_nr(pdev->bus), pdev->bus->number,
3542				pdev->devfn);
3543	if (!iommu)
3544		return;
3545
3546	spin_lock_irqsave(&device_domain_lock, flags);
3547	list_for_each_safe(entry, tmp, &domain->devices) {
3548		info = list_entry(entry, struct device_domain_info, link);
3549		if (info->segment == pci_domain_nr(pdev->bus) &&
3550		    info->bus == pdev->bus->number &&
3551		    info->devfn == pdev->devfn) {
3552			list_del(&info->link);
3553			list_del(&info->global);
3554			if (info->dev)
3555				info->dev->dev.archdata.iommu = NULL;
3556			spin_unlock_irqrestore(&device_domain_lock, flags);
3557
3558			iommu_disable_dev_iotlb(info);
3559			iommu_detach_dev(iommu, info->bus, info->devfn);
3560			iommu_detach_dependent_devices(iommu, pdev);
3561			free_devinfo_mem(info);
3562
3563			spin_lock_irqsave(&device_domain_lock, flags);
3564
3565			if (found)
3566				break;
3567			else
3568				continue;
3569		}
3570
3571		/* if there is no other devices under the same iommu
3572		 * owned by this domain, clear this iommu in iommu_bmp
3573		 * update iommu count and coherency
3574		 */
3575		if (iommu == device_to_iommu(info->segment, info->bus,
3576					    info->devfn))
3577			found = 1;
3578	}
3579
3580	spin_unlock_irqrestore(&device_domain_lock, flags);
3581
3582	if (found == 0) {
3583		unsigned long tmp_flags;
3584		spin_lock_irqsave(&domain->iommu_lock, tmp_flags);
3585		clear_bit(iommu->seq_id, &domain->iommu_bmp);
3586		domain->iommu_count--;
3587		domain_update_iommu_cap(domain);
3588		spin_unlock_irqrestore(&domain->iommu_lock, tmp_flags);
3589
3590		if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&
3591		    !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY)) {
3592			spin_lock_irqsave(&iommu->lock, tmp_flags);
3593			clear_bit(domain->id, iommu->domain_ids);
3594			iommu->domains[domain->id] = NULL;
3595			spin_unlock_irqrestore(&iommu->lock, tmp_flags);
3596		}
3597	}
3598}
3599
3600static void vm_domain_remove_all_dev_info(struct dmar_domain *domain)
3601{
3602	struct device_domain_info *info;
3603	struct intel_iommu *iommu;
3604	unsigned long flags1, flags2;
3605
3606	spin_lock_irqsave(&device_domain_lock, flags1);
3607	while (!list_empty(&domain->devices)) {
3608		info = list_entry(domain->devices.next,
3609			struct device_domain_info, link);
3610		list_del(&info->link);
3611		list_del(&info->global);
3612		if (info->dev)
3613			info->dev->dev.archdata.iommu = NULL;
3614
3615		spin_unlock_irqrestore(&device_domain_lock, flags1);
3616
3617		iommu_disable_dev_iotlb(info);
3618		iommu = device_to_iommu(info->segment, info->bus, info->devfn);
3619		iommu_detach_dev(iommu, info->bus, info->devfn);
3620		iommu_detach_dependent_devices(iommu, info->dev);
3621
3622		/* clear this iommu in iommu_bmp, update iommu count
3623		 * and capabilities
3624		 */
3625		spin_lock_irqsave(&domain->iommu_lock, flags2);
3626		if (test_and_clear_bit(iommu->seq_id,
3627				       &domain->iommu_bmp)) {
3628			domain->iommu_count--;
3629			domain_update_iommu_cap(domain);
3630		}
3631		spin_unlock_irqrestore(&domain->iommu_lock, flags2);
3632
3633		free_devinfo_mem(info);
3634		spin_lock_irqsave(&device_domain_lock, flags1);
3635	}
3636	spin_unlock_irqrestore(&device_domain_lock, flags1);
3637}
3638
3639/* domain id for virtual machine, it won't be set in context */
3640static unsigned long vm_domid;
3641
3642static struct dmar_domain *iommu_alloc_vm_domain(void)
3643{
3644	struct dmar_domain *domain;
3645
3646	domain = alloc_domain_mem();
3647	if (!domain)
3648		return NULL;
3649
3650	domain->id = vm_domid++;
3651	domain->nid = -1;
3652	memset(&domain->iommu_bmp, 0, sizeof(unsigned long));
3653	domain->flags = DOMAIN_FLAG_VIRTUAL_MACHINE;
3654
3655	return domain;
3656}
3657
3658static int md_domain_init(struct dmar_domain *domain, int guest_width)
3659{
3660	int adjust_width;
3661
3662	init_iova_domain(&domain->iovad, DMA_32BIT_PFN);
3663	spin_lock_init(&domain->iommu_lock);
3664
3665	domain_reserve_special_ranges(domain);
3666
3667	/* calculate AGAW */
3668	domain->gaw = guest_width;
3669	adjust_width = guestwidth_to_adjustwidth(guest_width);
3670	domain->agaw = width_to_agaw(adjust_width);
3671
3672	INIT_LIST_HEAD(&domain->devices);
3673
3674	domain->iommu_count = 0;
3675	domain->iommu_coherency = 0;
3676	domain->iommu_snooping = 0;
3677	domain->iommu_superpage = 0;
3678	domain->max_addr = 0;
3679	domain->nid = -1;
3680
3681	/* always allocate the top pgd */
3682	domain->pgd = (struct dma_pte *)alloc_pgtable_page(domain->nid);
3683	if (!domain->pgd)
3684		return -ENOMEM;
3685	domain_flush_cache(domain, domain->pgd, PAGE_SIZE);
3686	return 0;
3687}
3688
3689static void iommu_free_vm_domain(struct dmar_domain *domain)
3690{
3691	unsigned long flags;
3692	struct dmar_drhd_unit *drhd;
3693	struct intel_iommu *iommu;
3694	unsigned long i;
3695	unsigned long ndomains;
3696
3697	for_each_drhd_unit(drhd) {
3698		if (drhd->ignored)
3699			continue;
3700		iommu = drhd->iommu;
3701
3702		ndomains = cap_ndoms(iommu->cap);
3703		for_each_set_bit(i, iommu->domain_ids, ndomains) {
3704			if (iommu->domains[i] == domain) {
3705				spin_lock_irqsave(&iommu->lock, flags);
3706				clear_bit(i, iommu->domain_ids);
3707				iommu->domains[i] = NULL;
3708				spin_unlock_irqrestore(&iommu->lock, flags);
3709				break;
3710			}
3711		}
3712	}
3713}
3714
3715static void vm_domain_exit(struct dmar_domain *domain)
3716{
3717	/* Domain 0 is reserved, so dont process it */
3718	if (!domain)
3719		return;
3720
3721	vm_domain_remove_all_dev_info(domain);
3722	/* destroy iovas */
3723	put_iova_domain(&domain->iovad);
3724
3725	/* clear ptes */
3726	dma_pte_clear_range(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
3727
3728	/* free page tables */
3729	dma_pte_free_pagetable(domain, 0, DOMAIN_MAX_PFN(domain->gaw));
3730
3731	iommu_free_vm_domain(domain);
3732	free_domain_mem(domain);
3733}
3734
3735static int intel_iommu_domain_init(struct iommu_domain *domain)
3736{
3737	struct dmar_domain *dmar_domain;
3738
3739	dmar_domain = iommu_alloc_vm_domain();
3740	if (!dmar_domain) {
3741		printk(KERN_ERR
3742			"intel_iommu_domain_init: dmar_domain == NULL\n");
3743		return -ENOMEM;
3744	}
3745	if (md_domain_init(dmar_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
3746		printk(KERN_ERR
3747			"intel_iommu_domain_init() failed\n");
3748		vm_domain_exit(dmar_domain);
3749		return -ENOMEM;
3750	}
3751	domain_update_iommu_cap(dmar_domain);
3752	domain->priv = dmar_domain;
3753
3754	return 0;
3755}
3756
3757static void intel_iommu_domain_destroy(struct iommu_domain *domain)
3758{
3759	struct dmar_domain *dmar_domain = domain->priv;
3760
3761	domain->priv = NULL;
3762	vm_domain_exit(dmar_domain);
3763}
3764
3765static int intel_iommu_attach_device(struct iommu_domain *domain,
3766				     struct device *dev)
3767{
3768	struct dmar_domain *dmar_domain = domain->priv;
3769	struct pci_dev *pdev = to_pci_dev(dev);
3770	struct intel_iommu *iommu;
3771	int addr_width;
3772
3773	/* normally pdev is not mapped */
3774	if (unlikely(domain_context_mapped(pdev))) {
3775		struct dmar_domain *old_domain;
3776
3777		old_domain = find_domain(pdev);
3778		if (old_domain) {
3779			if (dmar_domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE ||
3780			    dmar_domain->flags & DOMAIN_FLAG_STATIC_IDENTITY)
3781				domain_remove_one_dev_info(old_domain, pdev);
3782			else
3783				domain_remove_dev_info(old_domain);
3784		}
3785	}
3786
3787	iommu = device_to_iommu(pci_domain_nr(pdev->bus), pdev->bus->number,
3788				pdev->devfn);
3789	if (!iommu)
3790		return -ENODEV;
3791
3792	/* check if this iommu agaw is sufficient for max mapped address */
3793	addr_width = agaw_to_width(iommu->agaw);
3794	if (addr_width > cap_mgaw(iommu->cap))
3795		addr_width = cap_mgaw(iommu->cap);
3796
3797	if (dmar_domain->max_addr > (1LL << addr_width)) {
3798		printk(KERN_ERR "%s: iommu width (%d) is not "
3799		       "sufficient for the mapped address (%llx)\n",
3800		       __func__, addr_width, dmar_domain->max_addr);
3801		return -EFAULT;
3802	}
3803	dmar_domain->gaw = addr_width;
3804
3805	/*
3806	 * Knock out extra levels of page tables if necessary
3807	 */
3808	while (iommu->agaw < dmar_domain->agaw) {
3809		struct dma_pte *pte;
3810
3811		pte = dmar_domain->pgd;
3812		if (dma_pte_present(pte)) {
3813			dmar_domain->pgd = (struct dma_pte *)
3814				phys_to_virt(dma_pte_addr(pte));
3815			free_pgtable_page(pte);
3816		}
3817		dmar_domain->agaw--;
3818	}
3819
3820	return domain_add_dev_info(dmar_domain, pdev, CONTEXT_TT_MULTI_LEVEL);
3821}
3822
3823static void intel_iommu_detach_device(struct iommu_domain *domain,
3824				      struct device *dev)
3825{
3826	struct dmar_domain *dmar_domain = domain->priv;
3827	struct pci_dev *pdev = to_pci_dev(dev);
3828
3829	domain_remove_one_dev_info(dmar_domain, pdev);
3830}
3831
3832static int intel_iommu_map(struct iommu_domain *domain,
3833			   unsigned long iova, phys_addr_t hpa,
3834			   int gfp_order, int iommu_prot)
3835{
3836	struct dmar_domain *dmar_domain = domain->priv;
3837	u64 max_addr;
3838	int prot = 0;
3839	size_t size;
3840	int ret;
3841
3842	if (iommu_prot & IOMMU_READ)
3843		prot |= DMA_PTE_READ;
3844	if (iommu_prot & IOMMU_WRITE)
3845		prot |= DMA_PTE_WRITE;
3846	if ((iommu_prot & IOMMU_CACHE) && dmar_domain->iommu_snooping)
3847		prot |= DMA_PTE_SNP;
3848
3849	size     = PAGE_SIZE << gfp_order;
3850	max_addr = iova + size;
3851	if (dmar_domain->max_addr < max_addr) {
3852		u64 end;
3853
3854		/* check if minimum agaw is sufficient for mapped address */
3855		end = __DOMAIN_MAX_ADDR(dmar_domain->gaw) + 1;
3856		if (end < max_addr) {
3857			printk(KERN_ERR "%s: iommu width (%d) is not "
3858			       "sufficient for the mapped address (%llx)\n",
3859			       __func__, dmar_domain->gaw, max_addr);
3860			return -EFAULT;
3861		}
3862		dmar_domain->max_addr = max_addr;
3863	}
3864	/* Round up size to next multiple of PAGE_SIZE, if it and
3865	   the low bits of hpa would take us onto the next page */
3866	size = aligned_nrpages(hpa, size);
3867	ret = domain_pfn_mapping(dmar_domain, iova >> VTD_PAGE_SHIFT,
3868				 hpa >> VTD_PAGE_SHIFT, size, prot);
3869	return ret;
3870}
3871
3872static int intel_iommu_unmap(struct iommu_domain *domain,
3873			     unsigned long iova, int gfp_order)
3874{
3875	struct dmar_domain *dmar_domain = domain->priv;
3876	size_t size = PAGE_SIZE << gfp_order;
3877	int order;
3878
3879	order = dma_pte_clear_range(dmar_domain, iova >> VTD_PAGE_SHIFT,
3880			    (iova + size - 1) >> VTD_PAGE_SHIFT);
3881
3882	if (dmar_domain->max_addr == iova + size)
3883		dmar_domain->max_addr = iova;
3884
3885	return order;
3886}
3887
3888static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
3889					    unsigned long iova)
3890{
3891	struct dmar_domain *dmar_domain = domain->priv;
3892	struct dma_pte *pte;
3893	u64 phys = 0;
3894
3895	pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, 0);
3896	if (pte)
3897		phys = dma_pte_addr(pte);
3898
3899	return phys;
3900}
3901
3902static int intel_iommu_domain_has_cap(struct iommu_domain *domain,
3903				      unsigned long cap)
3904{
3905	struct dmar_domain *dmar_domain = domain->priv;
3906
3907	if (cap == IOMMU_CAP_CACHE_COHERENCY)
3908		return dmar_domain->iommu_snooping;
3909	if (cap == IOMMU_CAP_INTR_REMAP)
3910		return intr_remapping_enabled;
3911
3912	return 0;
3913}
3914
3915static struct iommu_ops intel_iommu_ops = {
3916	.domain_init	= intel_iommu_domain_init,
3917	.domain_destroy = intel_iommu_domain_destroy,
3918	.attach_dev	= intel_iommu_attach_device,
3919	.detach_dev	= intel_iommu_detach_device,
3920	.map		= intel_iommu_map,
3921	.unmap		= intel_iommu_unmap,
3922	.iova_to_phys	= intel_iommu_iova_to_phys,
3923	.domain_has_cap = intel_iommu_domain_has_cap,
3924};
3925
3926static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)
3927{
3928	/*
3929	 * Mobile 4 Series Chipset neglects to set RWBF capability,
3930	 * but needs it:
3931	 */
3932	printk(KERN_INFO "DMAR: Forcing write-buffer flush capability\n");
3933	rwbf_quirk = 1;
3934
3935	/* https://bugzilla.redhat.com/show_bug.cgi?id=538163 */
3936	if (dev->revision == 0x07) {
3937		printk(KERN_INFO "DMAR: Disabling IOMMU for graphics on this chipset\n");
3938		dmar_map_gfx = 0;
3939	}
3940}
3941
3942DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf);
3943
3944#define GGC 0x52
3945#define GGC_MEMORY_SIZE_MASK	(0xf << 8)
3946#define GGC_MEMORY_SIZE_NONE	(0x0 << 8)
3947#define GGC_MEMORY_SIZE_1M	(0x1 << 8)
3948#define GGC_MEMORY_SIZE_2M	(0x3 << 8)
3949#define GGC_MEMORY_VT_ENABLED	(0x8 << 8)
3950#define GGC_MEMORY_SIZE_2M_VT	(0x9 << 8)
3951#define GGC_MEMORY_SIZE_3M_VT	(0xa << 8)
3952#define GGC_MEMORY_SIZE_4M_VT	(0xb << 8)
3953
3954static void __devinit quirk_calpella_no_shadow_gtt(struct pci_dev *dev)
3955{
3956	unsigned short ggc;
3957
3958	if (pci_read_config_word(dev, GGC, &ggc))
3959		return;
3960
3961	if (!(ggc & GGC_MEMORY_VT_ENABLED)) {
3962		printk(KERN_INFO "DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics\n");
3963		dmar_map_gfx = 0;
3964	} else if (dmar_map_gfx) {
3965		/* we have to ensure the gfx device is idle before we flush */
3966		printk(KERN_INFO "DMAR: Disabling batched IOTLB flush on Ironlake\n");
3967		intel_iommu_strict = 1;
3968       }
3969}
3970DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0040, quirk_calpella_no_shadow_gtt);
3971DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0044, quirk_calpella_no_shadow_gtt);
3972DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0062, quirk_calpella_no_shadow_gtt);
3973DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x006a, quirk_calpella_no_shadow_gtt);
3974
3975/* On Tylersburg chipsets, some BIOSes have been known to enable the
3976   ISOCH DMAR unit for the Azalia sound device, but not give it any
3977   TLB entries, which causes it to deadlock. Check for that.  We do
3978   this in a function called from init_dmars(), instead of in a PCI
3979   quirk, because we don't want to print the obnoxious "BIOS broken"
3980   message if VT-d is actually disabled.
3981*/
3982static void __init check_tylersburg_isoch(void)
3983{
3984	struct pci_dev *pdev;
3985	uint32_t vtisochctrl;
3986
3987	/* If there's no Azalia in the system anyway, forget it. */
3988	pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x3a3e, NULL);
3989	if (!pdev)
3990		return;
3991	pci_dev_put(pdev);
3992
3993	/* System Management Registers. Might be hidden, in which case
3994	   we can't do the sanity check. But that's OK, because the
3995	   known-broken BIOSes _don't_ actually hide it, so far. */
3996	pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x342e, NULL);
3997	if (!pdev)
3998		return;
3999
4000	if (pci_read_config_dword(pdev, 0x188, &vtisochctrl)) {
4001		pci_dev_put(pdev);
4002		return;
4003	}
4004
4005	pci_dev_put(pdev);
4006
4007	/* If Azalia DMA is routed to the non-isoch DMAR unit, fine. */
4008	if (vtisochctrl & 1)
4009		return;
4010
4011	/* Drop all bits other than the number of TLB entries */
4012	vtisochctrl &= 0x1c;
4013
4014	/* If we have the recommended number of TLB entries (16), fine. */
4015	if (vtisochctrl == 0x10)
4016		return;
4017
4018	/* Zero TLB entries? You get to ride the short bus to school. */
4019	if (!vtisochctrl) {
4020		WARN(1, "Your BIOS is broken; DMA routed to ISOCH DMAR unit but no TLB space.\n"
4021		     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
4022		     dmi_get_system_info(DMI_BIOS_VENDOR),
4023		     dmi_get_system_info(DMI_BIOS_VERSION),
4024		     dmi_get_system_info(DMI_PRODUCT_VERSION));
4025		iommu_identity_mapping |= IDENTMAP_AZALIA;
4026		return;
4027	}
4028	
4029	printk(KERN_WARNING "DMAR: Recommended TLB entries for ISOCH unit is 16; your BIOS set %d\n",
4030	       vtisochctrl);
4031}