Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (63 commits) x86, Calgary IOMMU quirk: Find nearest matching Calgary while walking up the PCI tree x86/amd-iommu: Remove amd_iommu_pd_table x86/amd-iommu: Move reset_iommu_command_buffer out of locked code x86/amd-iommu: Cleanup DTE flushing code x86/amd-iommu: Introduce iommu_flush_device() function x86/amd-iommu: Cleanup attach/detach_device code x86/amd-iommu: Keep devices per domain in a list x86/amd-iommu: Add device bind reference counting x86/amd-iommu: Use dev->arch->iommu to store iommu related information x86/amd-iommu: Remove support for domain sharing x86/amd-iommu: Rearrange dma_ops related functions x86/amd-iommu: Move some pte allocation functions in the right section x86/amd-iommu: Remove iommu parameter from dma_ops_domain_alloc x86/amd-iommu: Use get_device_id and check_device where appropriate x86/amd-iommu: Move find_protection_domain to helper functions x86/amd-iommu: Simplify get_device_resources() x86/amd-iommu: Let domain_for_device handle aliases x86/amd-iommu: Remove iommu specific handling from dma_ops path x86/amd-iommu: Remove iommu parameter from __(un)map_single x86/amd-iommu: Make alloc_new_range aware of multiple IOMMUs ...
2009-12-05 09:49:07 -08:00
parent 1ebb275afc 4528752f49
commit 7b626acb8f
33 changed files with 1073 additions and 888 deletions
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
+ * Copyright (C) 2007-2009 Advanced Micro Devices, Inc.
 * Author: Joerg Roedel <joerg.roedel@amd.com>
 *         Leo Duran <leo.duran@amd.com>
 *
@@ -25,10 +25,12 @@
 #include <linux/interrupt.h>
 #include <linux/msi.h>
 #include <asm/pci-direct.h>
+#include <asm/amd_iommu_proto.h>
 #include <asm/amd_iommu_types.h>
 #include <asm/amd_iommu.h>
 #include <asm/iommu.h>
 #include <asm/gart.h>
+#include <asm/x86_init.h>

 /*
 * definitions for the ACPI scanning code
@@ -123,18 +125,24 @@ u16 amd_iommu_last_bdf;			/* largest PCI device id we have
 					   to handle */
 LIST_HEAD(amd_iommu_unity_map);		/* a list of required unity mappings
 					   we find in ACPI */
-#ifdef CONFIG_IOMMU_STRESS
-bool amd_iommu_isolate = false;
-#else
-bool amd_iommu_isolate = true;		/* if true, device isolation is
-					   enabled */
-#endif
-
 bool amd_iommu_unmap_flush;		/* if true, flush on every unmap */

 LIST_HEAD(amd_iommu_list);		/* list of all AMD IOMMUs in the
 					   system */

+/* Array to assign indices to IOMMUs*/
+struct amd_iommu *amd_iommus[MAX_IOMMUS];
+int amd_iommus_present;
+
+/* IOMMUs have a non-present cache? */
+bool amd_iommu_np_cache __read_mostly;
+
+/*
+ * List of protection domains - used during resume
+ */
+LIST_HEAD(amd_iommu_pd_list);
+spinlock_t amd_iommu_pd_lock;
+
 /*
 * Pointer to the device table which is shared by all AMD IOMMUs
 * it is indexed by the PCI device id or the HT unit id and contains
@@ -156,12 +164,6 @@ u16 *amd_iommu_alias_table;
 */
 struct amd_iommu **amd_iommu_rlookup_table;

-/*
- * The pd table (protection domain table) is used to find the protection domain
- * data structure a device belongs to. Indexed with the PCI device id too.
- */
-struct protection_domain **amd_iommu_pd_table;
-
 /*
 * AMD IOMMU allows up to 2^16 differend protection domains. This is a bitmap
 * to know which ones are already in use.
@@ -838,7 +840,18 @@ static void __init free_iommu_all(void)
 static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 {
 	spin_lock_init(&iommu->lock);
+
+	/* Add IOMMU to internal data structures */
 	list_add_tail(&iommu->list, &amd_iommu_list);
+	iommu->index             = amd_iommus_present++;
+
+	if (unlikely(iommu->index >= MAX_IOMMUS)) {
+		WARN(1, "AMD-Vi: System has more IOMMUs than supported by this driver\n");
+		return -ENOSYS;
+	}
+
+	/* Index is fine - add IOMMU to the array */
+	amd_iommus[iommu->index] = iommu;

 	/*
 	 * Copy data from ACPI table entry to the iommu struct
@@ -868,6 +881,9 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 	init_iommu_from_acpi(iommu, h);
 	init_iommu_devices(iommu);

+	if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE))
+		amd_iommu_np_cache = true;
+
 	return pci_enable_device(iommu->dev);
 }

@@ -925,7 +941,7 @@ static int __init init_iommu_all(struct acpi_table_header *table)
 *
 ****************************************************************************/

-static int __init iommu_setup_msi(struct amd_iommu *iommu)
+static int iommu_setup_msi(struct amd_iommu *iommu)
 {
 	int r;

@@ -1176,19 +1192,10 @@ static struct sys_device device_amd_iommu = {
 * functions. Finally it prints some information about AMD IOMMUs and
 * the driver state and enables the hardware.
 */
-int __init amd_iommu_init(void)
+static int __init amd_iommu_init(void)
 {
 	int i, ret = 0;

-
-	if (no_iommu) {
-		printk(KERN_INFO "AMD-Vi disabled by kernel command line\n");
-		return 0;
-	}
-
-	if (!amd_iommu_detected)
-		return -ENODEV;
-
 	/*
 	 * First parse ACPI tables to find the largest Bus/Dev/Func
 	 * we need to handle. Upon this information the shared data
@@ -1225,15 +1232,6 @@ int __init amd_iommu_init(void)
 	if (amd_iommu_rlookup_table == NULL)
 		goto free;

-	/*
-	 * Protection Domain table - maps devices to protection domains
-	 * This table has the same size as the rlookup_table
-	 */
-	amd_iommu_pd_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
-				     get_order(rlookup_table_size));
-	if (amd_iommu_pd_table == NULL)
-		goto free;
-
 	amd_iommu_pd_alloc_bitmap = (void *)__get_free_pages(
 					    GFP_KERNEL | __GFP_ZERO,
 					    get_order(MAX_DOMAIN_ID/8));
@@ -1255,6 +1253,8 @@ int __init amd_iommu_init(void)
 	 */
 	amd_iommu_pd_alloc_bitmap[0] = 1;

+	spin_lock_init(&amd_iommu_pd_lock);
+
 	/*
 	 * now the data structures are allocated and basically initialized
 	 * start the real acpi table scan
@@ -1286,17 +1286,12 @@ int __init amd_iommu_init(void)
 	if (iommu_pass_through)
 		goto out;

-	printk(KERN_INFO "AMD-Vi: device isolation ");
-	if (amd_iommu_isolate)
-		printk("enabled\n");
-	else
-		printk("disabled\n");
-
 	if (amd_iommu_unmap_flush)
 		printk(KERN_INFO "AMD-Vi: IO/TLB flush on unmap enabled\n");
 	else
 		printk(KERN_INFO "AMD-Vi: Lazy IO/TLB flushing enabled\n");

+	x86_platform.iommu_shutdown = disable_iommus;
 out:
 	return ret;

@@ -1304,9 +1299,6 @@ free:
 	free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
 		   get_order(MAX_DOMAIN_ID/8));

-	free_pages((unsigned long)amd_iommu_pd_table,
-		   get_order(rlookup_table_size));
-
 	free_pages((unsigned long)amd_iommu_rlookup_table,
 		   get_order(rlookup_table_size));

@@ -1323,11 +1315,6 @@ free:
 	goto out;
 }

-void amd_iommu_shutdown(void)
-{
-	disable_iommus();
-}
-
 /****************************************************************************
 *
 * Early detect code. This code runs at IOMMU detection time in the DMA
@@ -1342,16 +1329,13 @@ static int __init early_amd_iommu_detect(struct acpi_table_header *table)

 void __init amd_iommu_detect(void)
 {
-	if (swiotlb || no_iommu || (iommu_detected && !gart_iommu_aperture))
+	if (no_iommu || (iommu_detected && !gart_iommu_aperture))
 		return;

 	if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) {
 		iommu_detected = 1;
 		amd_iommu_detected = 1;
-#ifdef CONFIG_GART_IOMMU
-		gart_iommu_aperture_disabled = 1;
-		gart_iommu_aperture = 0;
-#endif
+		x86_init.iommu.iommu_init = amd_iommu_init;
 	}
 }

@@ -1372,10 +1356,6 @@ static int __init parse_amd_iommu_dump(char *str)
 static int __init parse_amd_iommu_options(char *str)
 {
 	for (; *str; ++str) {
-		if (strncmp(str, "isolate", 7) == 0)
-			amd_iommu_isolate = true;
-		if (strncmp(str, "share", 5) == 0)
-			amd_iommu_isolate = false;
 		if (strncmp(str, "fullflush", 9) == 0)
 			amd_iommu_unmap_flush = true;
 	}
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -28,6 +28,7 @@
 #include <asm/pci-direct.h>
 #include <asm/dma.h>
 #include <asm/k8.h>
+#include <asm/x86_init.h>

 int gart_iommu_aperture;
 int gart_iommu_aperture_disabled __initdata;
@@ -400,6 +401,7 @@ void __init gart_iommu_hole_init(void)

 			iommu_detected = 1;
 			gart_iommu_aperture = 1;
+			x86_init.iommu.iommu_init = gart_iommu_init;

 			aper_order = (read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL) >> 1) & 7;
 			aper_size = (32 * 1024 * 1024) << aper_order;
@@ -456,7 +458,7 @@ out:

 	if (aper_alloc) {
 		/* Got the aperture from the AGP bridge */
-	} else if (swiotlb && !valid_agp) {
+	} else if (!valid_agp) {
 		/* Do nothing */
 	} else if ((!no_iommu && max_pfn > MAX_DMA32_PFN) ||
 		   force_iommu ||
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -27,8 +27,7 @@
 #include <asm/cpu.h>
 #include <asm/reboot.h>
 #include <asm/virtext.h>
-#include <asm/iommu.h>
-
+#include <asm/x86_init.h>

 #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)

@@ -106,7 +105,7 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
 #endif

 #ifdef CONFIG_X86_64
-	pci_iommu_shutdown();
+	x86_platform.iommu_shutdown();
 #endif

 	crash_save_cpu(regs, safe_smp_processor_id());
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -46,6 +46,7 @@
 #include <asm/dma.h>
 #include <asm/rio.h>
 #include <asm/bios_ebda.h>
+#include <asm/x86_init.h>

 #ifdef CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT
 int use_calgary __read_mostly = 1;
@@ -244,7 +245,7 @@ static unsigned long iommu_range_alloc(struct device *dev,
 			if (panic_on_overflow)
 				panic("Calgary: fix the allocator.\n");
 			else
-				return bad_dma_address;
+				return DMA_ERROR_CODE;
 		}
 	}

@@ -260,12 +261,15 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 			      void *vaddr, unsigned int npages, int direction)
 {
 	unsigned long entry;
-	dma_addr_t ret = bad_dma_address;
+	dma_addr_t ret;

 	entry = iommu_range_alloc(dev, tbl, npages);

-	if (unlikely(entry == bad_dma_address))
-		goto error;
+	if (unlikely(entry == DMA_ERROR_CODE)) {
+		printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
+		       "iommu %p\n", npages, tbl);
+		return DMA_ERROR_CODE;
+	}

 	/* set the return dma address */
 	ret = (entry << PAGE_SHIFT) | ((unsigned long)vaddr & ~PAGE_MASK);
@@ -273,13 +277,7 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
 	/* put the TCEs in the HW table */
 	tce_build(tbl, entry, npages, (unsigned long)vaddr & PAGE_MASK,
 		  direction);
-
 	return ret;
-
-error:
-	printk(KERN_WARNING "Calgary: failed to allocate %u pages in "
-	       "iommu %p\n", npages, tbl);
-	return bad_dma_address;
 }

 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
@@ -290,8 +288,8 @@ static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
 	unsigned long flags;

 	/* were we called with bad_dma_address? */
-	badend = bad_dma_address + (EMERGENCY_PAGES * PAGE_SIZE);
-	if (unlikely((dma_addr >= bad_dma_address) && (dma_addr < badend))) {
+	badend = DMA_ERROR_CODE + (EMERGENCY_PAGES * PAGE_SIZE);
+	if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {
 		WARN(1, KERN_ERR "Calgary: driver tried unmapping bad DMA "
 		       "address 0x%Lx\n", dma_addr);
 		return;
@@ -318,13 +316,15 @@ static inline struct iommu_table *find_iommu_table(struct device *dev)

 	pdev = to_pci_dev(dev);

+	/* search up the device tree for an iommu */
 	pbus = pdev->bus;
-
-	/* is the device behind a bridge? Look for the root bus */
-	while (pbus->parent)
+	do {
+		tbl = pci_iommu(pbus);
+		if (tbl && tbl->it_busno == pbus->number)
+			break;
+		tbl = NULL;
 		pbus = pbus->parent;
-
-	tbl = pci_iommu(pbus);
+	} while (pbus);

 	BUG_ON(tbl && (tbl->it_busno != pbus->number));

@@ -373,7 +373,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 		npages = iommu_num_pages(vaddr, s->length, PAGE_SIZE);

 		entry = iommu_range_alloc(dev, tbl, npages);
-		if (entry == bad_dma_address) {
+		if (entry == DMA_ERROR_CODE) {
 			/* makes sure unmap knows to stop */
 			s->dma_length = 0;
 			goto error;
@@ -391,7 +391,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
 error:
 	calgary_unmap_sg(dev, sg, nelems, dir, NULL);
 	for_each_sg(sg, s, nelems, i) {
-		sg->dma_address = bad_dma_address;
+		sg->dma_address = DMA_ERROR_CODE;
 		sg->dma_length = 0;
 	}
 	return 0;
@@ -446,7 +446,7 @@ static void* calgary_alloc_coherent(struct device *dev, size_t size,

 	/* set up tces to cover the allocated range */
 	mapping = iommu_alloc(dev, tbl, ret, npages, DMA_BIDIRECTIONAL);
-	if (mapping == bad_dma_address)
+	if (mapping == DMA_ERROR_CODE)
 		goto free;
 	*dma_handle = mapping;
 	return ret;
@@ -727,7 +727,7 @@ static void __init calgary_reserve_regions(struct pci_dev *dev)
 	struct iommu_table *tbl = pci_iommu(dev->bus);

 	/* reserve EMERGENCY_PAGES from bad_dma_address and up */
-	iommu_range_reserve(tbl, bad_dma_address, EMERGENCY_PAGES);
+	iommu_range_reserve(tbl, DMA_ERROR_CODE, EMERGENCY_PAGES);

 	/* avoid the BIOS/VGA first 640KB-1MB region */
 	/* for CalIOC2 - avoid the entire first MB */
@@ -1344,6 +1344,23 @@ static void __init get_tce_space_from_tar(void)
 	return;
 }

+static int __init calgary_iommu_init(void)
+{
+	int ret;
+
+	/* ok, we're trying to use Calgary - let's roll */
+	printk(KERN_INFO "PCI-DMA: Using Calgary IOMMU\n");
+
+	ret = calgary_init();
+	if (ret) {
+		printk(KERN_ERR "PCI-DMA: Calgary init failed %d, "
+		       "falling back to no_iommu\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 void __init detect_calgary(void)
 {
 	int bus;
@@ -1357,7 +1374,7 @@ void __init detect_calgary(void)
 	 * if the user specified iommu=off or iommu=soft or we found
 	 * another HW IOMMU already, bail out.
 	 */
-	if (swiotlb || no_iommu || iommu_detected)
+	if (no_iommu || iommu_detected)
 		return;

 	if (!use_calgary)
@@ -1442,9 +1459,7 @@ void __init detect_calgary(void)
 		printk(KERN_INFO "PCI-DMA: Calgary TCE table spec is %d\n",
 		       specified_table_size);

-		/* swiotlb for devices that aren't behind the Calgary. */
-		if (max_pfn > MAX_DMA32_PFN)
-			swiotlb = 1;
+		x86_init.iommu.iommu_init = calgary_iommu_init;
 	}
 	return;

@@ -1457,35 +1472,6 @@ cleanup:
 	}
 }

-int __init calgary_iommu_init(void)
-{
-	int ret;
-
-	if (no_iommu || (swiotlb && !calgary_detected))
-		return -ENODEV;
-
-	if (!calgary_detected)
-		return -ENODEV;
-
-	/* ok, we're trying to use Calgary - let's roll */
-	printk(KERN_INFO "PCI-DMA: Using Calgary IOMMU\n");
-
-	ret = calgary_init();
-	if (ret) {
-		printk(KERN_ERR "PCI-DMA: Calgary init failed %d, "
-		       "falling back to no_iommu\n", ret);
-		return ret;
-	}
-
-	force_iommu = 1;
-	bad_dma_address = 0x0;
-	/* dma_ops is set to swiotlb or nommu */
-	if (!dma_ops)
-		dma_ops = &nommu_dma_ops;
-
-	return 0;
-}
-
 static int __init calgary_parse_options(char *p)
 {
 	unsigned int bridge;
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -11,10 +11,11 @@
 #include <asm/gart.h>
 #include <asm/calgary.h>
 #include <asm/amd_iommu.h>
+#include <asm/x86_init.h>

 static int forbid_dac __read_mostly;

-struct dma_map_ops *dma_ops;
+struct dma_map_ops *dma_ops = &nommu_dma_ops;
 EXPORT_SYMBOL(dma_ops);

 static int iommu_sac_force __read_mostly;
@@ -42,9 +43,6 @@ int iommu_detected __read_mostly = 0;
 */
 int iommu_pass_through __read_mostly;

-dma_addr_t bad_dma_address __read_mostly = 0;
-EXPORT_SYMBOL(bad_dma_address);
-
 /* Dummy device used for NULL arguments (normally ISA). */
 struct device x86_dma_fallback_dev = {
 	.init_name = "fallback device",
@@ -126,20 +124,17 @@ void __init pci_iommu_alloc(void)
 	/* free the range so iommu could get some range less than 4G */
 	dma32_free_bootmem();
 #endif
+	if (pci_swiotlb_init())
+		return;

-	/*
-	 * The order of these functions is important for
-	 * fall-back/fail-over reasons
-	 */
 	gart_iommu_hole_init();

 	detect_calgary();

 	detect_intel_iommu();

+	/* needs to be called after gart_iommu_hole_init */
 	amd_iommu_detect();
-
-	pci_swiotlb_init();
 }

 void *dma_generic_alloc_coherent(struct device *dev, size_t size,
@@ -214,7 +209,7 @@ static __init int iommu_setup(char *p)
 		if (!strncmp(p, "allowdac", 8))
 			forbid_dac = 0;
 		if (!strncmp(p, "nodac", 5))
-			forbid_dac = -1;
+			forbid_dac = 1;
 		if (!strncmp(p, "usedac", 6)) {
 			forbid_dac = -1;
 			return 1;
@@ -289,25 +284,17 @@ static int __init pci_iommu_init(void)
 #ifdef CONFIG_PCI
 	dma_debug_add_bus(&pci_bus_type);
 #endif
+	x86_init.iommu.iommu_init();

-	calgary_iommu_init();
+	if (swiotlb) {
+		printk(KERN_INFO "PCI-DMA: "
+		       "Using software bounce buffering for IO (SWIOTLB)\n");
+		swiotlb_print_info();
+	} else
+		swiotlb_free();

-	intel_iommu_init();
-
-	amd_iommu_init();
-
-	gart_iommu_init();
-
-	no_iommu_init();
 	return 0;
 }
-
-void pci_iommu_shutdown(void)
-{
-	gart_iommu_shutdown();
-
-	amd_iommu_shutdown();
-}
 /* Must execute after PCI subsystem */
 rootfs_initcall(pci_iommu_init);

--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -39,6 +39,7 @@
 #include <asm/swiotlb.h>
 #include <asm/dma.h>
 #include <asm/k8.h>
+#include <asm/x86_init.h>

 static unsigned long iommu_bus_base;	/* GART remapping area (physical) */
 static unsigned long iommu_size;	/* size of remapping area bytes */
@@ -46,6 +47,8 @@ static unsigned long iommu_pages;	/* .. and in pages */

 static u32 *iommu_gatt_base;		/* Remapping table */

+static dma_addr_t bad_dma_addr;
+
 /*
 * If this is disabled the IOMMU will use an optimized flushing strategy
 * of only flushing when an mapping is reused. With it true the GART is
@@ -92,7 +95,7 @@ static unsigned long alloc_iommu(struct device *dev, int size,

 	base_index = ALIGN(iommu_bus_base & dma_get_seg_boundary(dev),
 			   PAGE_SIZE) >> PAGE_SHIFT;
-	boundary_size = ALIGN((unsigned long long)dma_get_seg_boundary(dev) + 1,
+	boundary_size = ALIGN((u64)dma_get_seg_boundary(dev) + 1,
 			      PAGE_SIZE) >> PAGE_SHIFT;

 	spin_lock_irqsave(&iommu_bitmap_lock, flags);
@@ -216,7 +219,7 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem,
 		if (panic_on_overflow)
 			panic("dma_map_area overflow %lu bytes\n", size);
 		iommu_full(dev, size, dir);
-		return bad_dma_address;
+		return bad_dma_addr;
 	}

 	for (i = 0; i < npages; i++) {
@@ -294,7 +297,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
 	int i;

 #ifdef CONFIG_IOMMU_DEBUG
-	printk(KERN_DEBUG "dma_map_sg overflow\n");
+	pr_debug("dma_map_sg overflow\n");
 #endif

 	for_each_sg(sg, s, nents, i) {
@@ -302,7 +305,7 @@ static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,

 		if (nonforced_iommu(dev, addr, s->length)) {
 			addr = dma_map_area(dev, addr, s->length, dir, 0);
-			if (addr == bad_dma_address) {
+			if (addr == bad_dma_addr) {
 				if (i > 0)
 					gart_unmap_sg(dev, sg, i, dir, NULL);
 				nents = 0;
@@ -389,12 +392,14 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 	if (!dev)
 		dev = &x86_dma_fallback_dev;

-	out = 0;
-	start = 0;
-	start_sg = sgmap = sg;
-	seg_size = 0;
-	max_seg_size = dma_get_max_seg_size(dev);
-	ps = NULL; /* shut up gcc */
+	out		= 0;
+	start		= 0;
+	start_sg	= sg;
+	sgmap		= sg;
+	seg_size	= 0;
+	max_seg_size	= dma_get_max_seg_size(dev);
+	ps		= NULL; /* shut up gcc */
+
 	for_each_sg(sg, s, nents, i) {
 		dma_addr_t addr = sg_phys(s);

@@ -417,11 +422,12 @@ static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 						 sgmap, pages, need) < 0)
 					goto error;
 				out++;
-				seg_size = 0;
-				sgmap = sg_next(sgmap);
-				pages = 0;
-				start = i;
-				start_sg = s;
+
+				seg_size	= 0;
+				sgmap		= sg_next(sgmap);
+				pages		= 0;
+				start		= i;
+				start_sg	= s;
 			}
 		}

@@ -455,7 +461,7 @@ error:

 	iommu_full(dev, pages << PAGE_SHIFT, dir);
 	for_each_sg(sg, s, nents, i)
-		s->dma_address = bad_dma_address;
+		s->dma_address = bad_dma_addr;
 	return 0;
 }

@@ -479,7 +485,7 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
 				     DMA_BIDIRECTIONAL, align_mask);

 		flush_gart();
-		if (paddr != bad_dma_address) {
+		if (paddr != bad_dma_addr) {
 			*dma_addr = paddr;
 			return page_address(page);
 		}
@@ -499,6 +505,11 @@ gart_free_coherent(struct device *dev, size_t size, void *vaddr,
 	free_pages((unsigned long)vaddr, get_order(size));
 }

+static int gart_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return (dma_addr == bad_dma_addr);
+}
+
 static int no_agp;

 static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
@@ -515,7 +526,7 @@ static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
 	iommu_size -= round_up(a, PMD_PAGE_SIZE) - a;

 	if (iommu_size < 64*1024*1024) {
-		printk(KERN_WARNING
+		pr_warning(
 			"PCI-DMA: Warning: Small IOMMU %luMB."
 			" Consider increasing the AGP aperture in BIOS\n",
 				iommu_size >> 20);
@@ -570,28 +581,32 @@ void set_up_gart_resume(u32 aper_order, u32 aper_alloc)
 	aperture_alloc = aper_alloc;
 }

+static void gart_fixup_northbridges(struct sys_device *dev)
+{
+	int i;
+
+	if (!fix_up_north_bridges)
+		return;
+
+	pr_info("PCI-DMA: Restoring GART aperture settings\n");
+
+	for (i = 0; i < num_k8_northbridges; i++) {
+		struct pci_dev *dev = k8_northbridges[i];
+
+		/*
+		 * Don't enable translations just yet.  That is the next
+		 * step.  Restore the pre-suspend aperture settings.
+		 */
+		pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, aperture_order << 1);
+		pci_write_config_dword(dev, AMD64_GARTAPERTUREBASE, aperture_alloc >> 25);
+	}
+}
+
 static int gart_resume(struct sys_device *dev)
 {
-	printk(KERN_INFO "PCI-DMA: Resuming GART IOMMU\n");
+	pr_info("PCI-DMA: Resuming GART IOMMU\n");

-	if (fix_up_north_bridges) {
-		int i;
-
-		printk(KERN_INFO "PCI-DMA: Restoring GART aperture settings\n");
-
-		for (i = 0; i < num_k8_northbridges; i++) {
-			struct pci_dev *dev = k8_northbridges[i];
-
-			/*
-			 * Don't enable translations just yet.  That is the next
-			 * step.  Restore the pre-suspend aperture settings.
-			 */
-			pci_write_config_dword(dev, AMD64_GARTAPERTURECTL,
-						aperture_order << 1);
-			pci_write_config_dword(dev, AMD64_GARTAPERTUREBASE,
-						aperture_alloc >> 25);
-		}
-	}
+	gart_fixup_northbridges(dev);

 	enable_gart_translations();

@@ -604,15 +619,14 @@ static int gart_suspend(struct sys_device *dev, pm_message_t state)
 }

 static struct sysdev_class gart_sysdev_class = {
-	.name = "gart",
-	.suspend = gart_suspend,
-	.resume = gart_resume,
+	.name		= "gart",
+	.suspend	= gart_suspend,
+	.resume		= gart_resume,

 };

 static struct sys_device device_gart = {
-	.id	= 0,
-	.cls	= &gart_sysdev_class,
+	.cls		= &gart_sysdev_class,
 };

 /*
@@ -627,7 +641,8 @@ static __init int init_k8_gatt(struct agp_kern_info *info)
 	void *gatt;
 	int i, error;

-	printk(KERN_INFO "PCI-DMA: Disabling AGP.\n");
+	pr_info("PCI-DMA: Disabling AGP.\n");
+
 	aper_size = aper_base = info->aper_size = 0;
 	dev = NULL;
 	for (i = 0; i < num_k8_northbridges; i++) {
@@ -645,6 +660,7 @@ static __init int init_k8_gatt(struct agp_kern_info *info)
 	}
 	if (!aper_base)
 		goto nommu;
+
 	info->aper_base = aper_base;
 	info->aper_size = aper_size >> 20;

@@ -667,14 +683,14 @@ static __init int init_k8_gatt(struct agp_kern_info *info)

 	flush_gart();

-	printk(KERN_INFO "PCI-DMA: aperture base @ %x size %u KB\n",
+	pr_info("PCI-DMA: aperture base @ %x size %u KB\n",
 	       aper_base, aper_size>>10);

 	return 0;

 nommu:
 	/* Should not happen anymore */
-	printk(KERN_WARNING "PCI-DMA: More than 4GB of RAM and no IOMMU\n"
+	pr_warning("PCI-DMA: More than 4GB of RAM and no IOMMU\n"
 	       "falling back to iommu=soft.\n");
 	return -1;
 }
@@ -686,14 +702,15 @@ static struct dma_map_ops gart_dma_ops = {
 	.unmap_page			= gart_unmap_page,
 	.alloc_coherent			= gart_alloc_coherent,
 	.free_coherent			= gart_free_coherent,
+	.mapping_error			= gart_mapping_error,
 };

-void gart_iommu_shutdown(void)
+static void gart_iommu_shutdown(void)
 {
 	struct pci_dev *dev;
 	int i;

-	if (no_agp && (dma_ops != &gart_dma_ops))
+	if (no_agp)
 		return;

 	for (i = 0; i < num_k8_northbridges; i++) {
@@ -708,7 +725,7 @@ void gart_iommu_shutdown(void)
 	}
 }

-void __init gart_iommu_init(void)
+int __init gart_iommu_init(void)
 {
 	struct agp_kern_info info;
 	unsigned long iommu_start;
@@ -718,7 +735,7 @@ void __init gart_iommu_init(void)
 	long i;

 	if (cache_k8_northbridges() < 0 || num_k8_northbridges == 0)
-		return;
+		return 0;

 #ifndef CONFIG_AGP_AMD64
 	no_agp = 1;
@@ -730,35 +747,28 @@ void __init gart_iommu_init(void)
 		(agp_copy_info(agp_bridge, &info) < 0);
 #endif

-	if (swiotlb)
-		return;
-
-	/* Did we detect a different HW IOMMU? */
-	if (iommu_detected && !gart_iommu_aperture)
-		return;
-
 	if (no_iommu ||
 	    (!force_iommu && max_pfn <= MAX_DMA32_PFN) ||
 	    !gart_iommu_aperture ||
 	    (no_agp && init_k8_gatt(&info) < 0)) {
 		if (max_pfn > MAX_DMA32_PFN) {
-			printk(KERN_WARNING "More than 4GB of memory "
-			       "but GART IOMMU not available.\n");
-			printk(KERN_WARNING "falling back to iommu=soft.\n");
+			pr_warning("More than 4GB of memory but GART IOMMU not available.\n");
+			pr_warning("falling back to iommu=soft.\n");
 		}
-		return;
+		return 0;
 	}

 	/* need to map that range */
-	aper_size = info.aper_size << 20;
-	aper_base = info.aper_base;
-	end_pfn = (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT);
+	aper_size	= info.aper_size << 20;
+	aper_base	= info.aper_base;
+	end_pfn		= (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT);
+
 	if (end_pfn > max_low_pfn_mapped) {
 		start_pfn = (aper_base>>PAGE_SHIFT);
 		init_memory_mapping(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
 	}

-	printk(KERN_INFO "PCI-DMA: using GART IOMMU.\n");
+	pr_info("PCI-DMA: using GART IOMMU.\n");
 	iommu_size = check_iommu_size(info.aper_base, aper_size);
 	iommu_pages = iommu_size >> PAGE_SHIFT;

@@ -773,8 +783,7 @@ void __init gart_iommu_init(void)

 		ret = dma_debug_resize_entries(iommu_pages);
 		if (ret)
-			printk(KERN_DEBUG
-			       "PCI-DMA: Cannot trace all the entries\n");
+			pr_debug("PCI-DMA: Cannot trace all the entries\n");
 	}
 #endif

@@ -784,15 +793,14 @@ void __init gart_iommu_init(void)
 	 */
 	iommu_area_reserve(iommu_gart_bitmap, 0, EMERGENCY_PAGES);

-	agp_memory_reserved = iommu_size;
-	printk(KERN_INFO
-	       "PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
+	pr_info("PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
 	       iommu_size >> 20);

-	iommu_start = aper_size - iommu_size;
-	iommu_bus_base = info.aper_base + iommu_start;
-	bad_dma_address = iommu_bus_base;
-	iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT);
+	agp_memory_reserved	= iommu_size;
+	iommu_start		= aper_size - iommu_size;
+	iommu_bus_base		= info.aper_base + iommu_start;
+	bad_dma_addr		= iommu_bus_base;
+	iommu_gatt_base		= agp_gatt_table + (iommu_start>>PAGE_SHIFT);

 	/*
 	 * Unmap the IOMMU part of the GART. The alias of the page is
@@ -814,7 +822,7 @@ void __init gart_iommu_init(void)
 	 * the pages as Not-Present:
 	 */
 	wbinvd();
-	
+
 	/*
 	 * Now all caches are flushed and we can safely enable
 	 * GART hardware.  Doing it early leaves the possibility
@@ -838,6 +846,10 @@ void __init gart_iommu_init(void)

 	flush_gart();
 	dma_ops = &gart_dma_ops;
+	x86_platform.iommu_shutdown = gart_iommu_shutdown;
+	swiotlb = 0;
+
+	return 0;
 }

 void __init gart_parse_options(char *p)
@@ -856,7 +868,7 @@ void __init gart_parse_options(char *p)
 #endif
 	if (isdigit(*p) && get_option(&p, &arg))
 		iommu_size = arg;
-	if (!strncmp(p, "fullflush", 8))
+	if (!strncmp(p, "fullflush", 9))
 		iommu_fullflush = 1;
 	if (!strncmp(p, "nofullflush", 11))
 		iommu_fullflush = 0;
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -33,7 +33,7 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page,
 	dma_addr_t bus = page_to_phys(page) + offset;
 	WARN_ON(size == 0);
 	if (!check_addr("map_single", dev, bus, size))
-		return bad_dma_address;
+		return DMA_ERROR_CODE;
 	flush_write_buffers();
 	return bus;
 }
@@ -103,12 +103,3 @@ struct dma_map_ops nommu_dma_ops = {
 	.sync_sg_for_device	= nommu_sync_sg_for_device,
 	.is_phys		= 1,
 };
-
-void __init no_iommu_init(void)
-{
-	if (dma_ops)
-		return;
-
-	force_iommu = 0; /* no HW IOMMU */
-	dma_ops = &nommu_dma_ops;
-}
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,18 +42,28 @@ static struct dma_map_ops swiotlb_dma_ops = {
 	.dma_supported = NULL,
 };

-void __init pci_swiotlb_init(void)
+/*
+ * pci_swiotlb_init - initialize swiotlb if necessary
+ *
+ * This returns non-zero if we are forced to use swiotlb (by the boot
+ * option).
+ */
+int __init pci_swiotlb_init(void)
 {
+	int use_swiotlb = swiotlb | swiotlb_force;
+
 	/* don't initialize swiotlb if iommu=off (no_iommu=1) */
 #ifdef CONFIG_X86_64
-	if ((!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN))
+	if (!no_iommu && max_pfn > MAX_DMA32_PFN)
 		swiotlb = 1;
 #endif
 	if (swiotlb_force)
 		swiotlb = 1;
+
 	if (swiotlb) {
-		printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
-		swiotlb_init();
+		swiotlb_init(0);
 		dma_ops = &swiotlb_dma_ops;
 	}
+
+	return use_swiotlb;
 }
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -23,7 +23,7 @@
 # include <linux/ctype.h>
 # include <linux/mc146818rtc.h>
 #else
-# include <asm/iommu.h>
+# include <asm/x86_init.h>
 #endif

 /*
@@ -622,7 +622,7 @@ void native_machine_shutdown(void)
 #endif

 #ifdef CONFIG_X86_64
-	pci_iommu_shutdown();
+	x86_platform.iommu_shutdown();
 #endif
 }

--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -14,10 +14,13 @@
 #include <asm/time.h>
 #include <asm/irq.h>
 #include <asm/tsc.h>
+#include <asm/iommu.h>

 void __cpuinit x86_init_noop(void) { }
 void __init x86_init_uint_noop(unsigned int unused) { }
 void __init x86_init_pgd_noop(pgd_t *unused) { }
+int __init iommu_init_noop(void) { return 0; }
+void iommu_shutdown_noop(void) { }

 /*
 * The platform setup functions are preset with the default functions
@@ -62,6 +65,10 @@ struct x86_init_ops x86_init __initdata = {
 		.tsc_pre_init		= x86_init_noop,
 		.timer_init		= hpet_time_init,
 	},
+
+	.iommu = {
+		.iommu_init		= iommu_init_noop,
+	},
 };

 struct x86_cpuinit_ops x86_cpuinit __cpuinitdata = {
@@ -72,4 +79,5 @@ struct x86_platform_ops x86_platform = {
 	.calibrate_tsc			= native_calibrate_tsc,
 	.get_wallclock			= mach_get_cmos_time,
 	.set_wallclock			= mach_set_rtc_mmss,
+	.iommu_shutdown			= iommu_shutdown_noop,
 };