diff options
| -rw-r--r-- | drivers/pci/dmar.c | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 525a32487abd..56883fc1c7be 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -632,6 +632,9 @@ int __init check_zero_address(void) } if (entry_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT) { + void __iomem *addr; + u64 cap, ecap; + drhd = (void *)entry_header; if (!drhd->address) { /* Promote an attitude of violence to a BIOS engineer today */ @@ -640,17 +643,38 @@ int __init check_zero_address(void) dmi_get_system_info(DMI_BIOS_VENDOR), dmi_get_system_info(DMI_BIOS_VERSION), dmi_get_system_info(DMI_PRODUCT_VERSION)); -#ifdef CONFIG_DMAR - dmar_disabled = 1; -#endif - return 0; + goto failed; + } + + addr = early_ioremap(drhd->address, VTD_PAGE_SIZE); + if (!addr ) { + printk("IOMMU: can't validate: %llx\n", drhd->address); + goto failed; + } + cap = dmar_readq(addr + DMAR_CAP_REG); + ecap = dmar_readq(addr + DMAR_ECAP_REG); + early_iounmap(addr, VTD_PAGE_SIZE); + if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) { + /* Promote an attitude of violence to a BIOS engineer today */ + WARN(1, "Your BIOS is broken; DMAR reported at address %llx returns all ones!\n" + "BIOS vendor: %s; Ver: %s; Product Version: %s\n", + drhd->address, + dmi_get_system_info(DMI_BIOS_VENDOR), + dmi_get_system_info(DMI_BIOS_VERSION), + dmi_get_system_info(DMI_PRODUCT_VERSION)); + goto failed; } - break; } entry_header = ((void *)entry_header + entry_header->length); } return 1; + +failed: +#ifdef CONFIG_DMAR + dmar_disabled = 1; +#endif + return 0; } void __init detect_intel_iommu(void) |