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authorDavid Woodhouse <David.Woodhouse@intel.com>2009-09-30 12:12:17 -0400
committerDavid Woodhouse <David.Woodhouse@intel.com>2009-09-30 12:12:17 -0400
commite0fc7e0b4b5e69616f10a894ab9afff3c64be74e (patch)
tree32b6d394c47bd61e530fd322d473dd79c9b70db9 /drivers/pci/intel-iommu.c
parent17b6097753e926ca546189463070a7e94e7ea9fa (diff)
intel-iommu: Yet another BIOS workaround: Isoch DMAR unit with no TLB space
Asus decided to ship a BIOS which configures sound DMA to go via the dedicated IOMMU unit, but assigns precisely zero TLB entries to that unit. Which causes the whole thing to deadlock, including the DMA traffic on the _other_ IOMMU units. Nice one. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/pci/intel-iommu.c')
-rw-r--r--drivers/pci/intel-iommu.c82
1 files changed, 77 insertions, 5 deletions
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 855dd7ca47f3..b1e97e682500 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -48,6 +48,7 @@
48 48
49#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY) 49#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
50#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA) 50#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
51#define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
51 52
52#define IOAPIC_RANGE_START (0xfee00000) 53#define IOAPIC_RANGE_START (0xfee00000)
53#define IOAPIC_RANGE_END (0xfeefffff) 54#define IOAPIC_RANGE_END (0xfeefffff)
@@ -94,6 +95,7 @@ static inline unsigned long virt_to_dma_pfn(void *p)
94/* global iommu list, set NULL for ignored DMAR units */ 95/* global iommu list, set NULL for ignored DMAR units */
95static struct intel_iommu **g_iommus; 96static struct intel_iommu **g_iommus;
96 97
98static void __init check_tylersburg_isoch(void);
97static int rwbf_quirk; 99static int rwbf_quirk;
98 100
99/* 101/*
@@ -1934,6 +1936,9 @@ error:
1934} 1936}
1935 1937
1936static int iommu_identity_mapping; 1938static int iommu_identity_mapping;
1939#define IDENTMAP_ALL 1
1940#define IDENTMAP_GFX 2
1941#define IDENTMAP_AZALIA 4
1937 1942
1938static int iommu_domain_identity_map(struct dmar_domain *domain, 1943static int iommu_domain_identity_map(struct dmar_domain *domain,
1939 unsigned long long start, 1944 unsigned long long start,
@@ -2151,8 +2156,14 @@ static int domain_add_dev_info(struct dmar_domain *domain,
2151 2156
2152static int iommu_should_identity_map(struct pci_dev *pdev, int startup) 2157static int iommu_should_identity_map(struct pci_dev *pdev, int startup)
2153{ 2158{
2154 if (iommu_identity_mapping == 2) 2159 if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
2155 return IS_GFX_DEVICE(pdev); 2160 return 1;
2161
2162 if ((iommu_identity_mapping & IDENTMAP_GFX) && IS_GFX_DEVICE(pdev))
2163 return 1;
2164
2165 if (!(iommu_identity_mapping & IDENTMAP_ALL))
2166 return 0;
2156 2167
2157 /* 2168 /*
2158 * We want to start off with all devices in the 1:1 domain, and 2169 * We want to start off with all devices in the 1:1 domain, and
@@ -2332,11 +2343,14 @@ int __init init_dmars(void)
2332 } 2343 }
2333 2344
2334 if (iommu_pass_through) 2345 if (iommu_pass_through)
2335 iommu_identity_mapping = 1; 2346 iommu_identity_mapping |= IDENTMAP_ALL;
2347
2336#ifdef CONFIG_DMAR_BROKEN_GFX_WA 2348#ifdef CONFIG_DMAR_BROKEN_GFX_WA
2337 else 2349 iommu_identity_mapping |= IDENTMAP_GFX;
2338 iommu_identity_mapping = 2;
2339#endif 2350#endif
2351
2352 check_tylersburg_isoch();
2353
2340 /* 2354 /*
2341 * If pass through is not set or not enabled, setup context entries for 2355 * If pass through is not set or not enabled, setup context entries for
2342 * identity mappings for rmrr, gfx, and isa and may fall back to static 2356 * identity mappings for rmrr, gfx, and isa and may fall back to static
@@ -3670,3 +3684,61 @@ static void __devinit quirk_iommu_rwbf(struct pci_dev *dev)
3670} 3684}
3671 3685
3672DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf); 3686DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf);
3687
3688/* On Tylersburg chipsets, some BIOSes have been known to enable the
3689 ISOCH DMAR unit for the Azalia sound device, but not give it any
3690 TLB entries, which causes it to deadlock. Check for that. We do
3691 this in a function called from init_dmars(), instead of in a PCI
3692 quirk, because we don't want to print the obnoxious "BIOS broken"
3693 message if VT-d is actually disabled.
3694*/
3695static void __init check_tylersburg_isoch(void)
3696{
3697 struct pci_dev *pdev;
3698 uint32_t vtisochctrl;
3699
3700 /* If there's no Azalia in the system anyway, forget it. */
3701 pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x3a3e, NULL);
3702 if (!pdev)
3703 return;
3704 pci_dev_put(pdev);
3705
3706 /* System Management Registers. Might be hidden, in which case
3707 we can't do the sanity check. But that's OK, because the
3708 known-broken BIOSes _don't_ actually hide it, so far. */
3709 pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x342e, NULL);
3710 if (!pdev)
3711 return;
3712
3713 if (pci_read_config_dword(pdev, 0x188, &vtisochctrl)) {
3714 pci_dev_put(pdev);
3715 return;
3716 }
3717
3718 pci_dev_put(pdev);
3719
3720 /* If Azalia DMA is routed to the non-isoch DMAR unit, fine. */
3721 if (vtisochctrl & 1)
3722 return;
3723
3724 /* Drop all bits other than the number of TLB entries */
3725 vtisochctrl &= 0x1c;
3726
3727 /* If we have the recommended number of TLB entries (16), fine. */
3728 if (vtisochctrl == 0x10)
3729 return;
3730
3731 /* Zero TLB entries? You get to ride the short bus to school. */
3732 if (!vtisochctrl) {
3733 WARN(1, "Your BIOS is broken; DMA routed to ISOCH DMAR unit but no TLB space.\n"
3734 "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
3735 dmi_get_system_info(DMI_BIOS_VENDOR),
3736 dmi_get_system_info(DMI_BIOS_VERSION),
3737 dmi_get_system_info(DMI_PRODUCT_VERSION));
3738 iommu_identity_mapping |= IDENTMAP_AZALIA;
3739 return;
3740 }
3741
3742 printk(KERN_WARNING "DMAR: Recommended TLB entries for ISOCH unit is 16; your BIOS set %d\n",
3743 vtisochctrl);
3744}