diff options
author | David Woodhouse <David.Woodhouse@intel.com> | 2009-11-09 22:15:15 (GMT) |
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committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-11-09 22:15:15 (GMT) |
commit | 86cf898e1d0fca245173980e3897580db38569a8 (patch) | |
tree | fe9ba4ed67ef8e5ae430f0d7d69fba68f70869d7 /drivers/pci/dmar.c | |
parent | 799dd75b1a8380a967c929a4551895788c374b31 (diff) | |
download | linux-86cf898e1d0fca245173980e3897580db38569a8.tar.xz |
intel-iommu: Check for 'DMAR at zero' BIOS error earlier.
Chris Wright has some patches which let us fall back to swiotlb nicely
if IOMMU initialisation fails. But those are a bit much for 2.6.32.
Instead, let's shift the check for the biggest problem, the HP and Acer
BIOS bug which reports a DMAR at physical address zero. That one can
actually be checked much earlier -- before we even admit to having
detected an IOMMU in the first place. So the swiotlb init goes ahead as
we want.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/pci/dmar.c')
-rw-r--r-- | drivers/pci/dmar.c | 49 |
1 files changed, 39 insertions, 10 deletions
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 22b02c6..e5f8fc1 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -175,15 +175,6 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header) int ret = 0; drhd = (struct acpi_dmar_hardware_unit *)header; - if (!drhd->address) { - /* Promote an attitude of violence to a BIOS engineer today */ - WARN(1, "Your BIOS is broken; DMAR reported at address zero!\n" - "BIOS vendor: %s; Ver: %s; Product Version: %s\n", - dmi_get_system_info(DMI_BIOS_VENDOR), - dmi_get_system_info(DMI_BIOS_VERSION), - dmi_get_system_info(DMI_PRODUCT_VERSION)); - return -ENODEV; - } dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL); if (!dmaru) return -ENOMEM; @@ -591,12 +582,50 @@ int __init dmar_table_init(void) return 0; } +int __init check_zero_address(void) +{ + struct acpi_table_dmar *dmar; + struct acpi_dmar_header *entry_header; + struct acpi_dmar_hardware_unit *drhd; + + dmar = (struct acpi_table_dmar *)dmar_tbl; + entry_header = (struct acpi_dmar_header *)(dmar + 1); + + while (((unsigned long)entry_header) < + (((unsigned long)dmar) + dmar_tbl->length)) { + /* Avoid looping forever on bad ACPI tables */ + if (entry_header->length == 0) { + printk(KERN_WARNING PREFIX + "Invalid 0-length structure\n"); + return 0; + } + + if (entry_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT) { + drhd = (void *)entry_header; + if (!drhd->address) { + /* Promote an attitude of violence to a BIOS engineer today */ + WARN(1, "Your BIOS is broken; DMAR reported at address zero!\n" + "BIOS vendor: %s; Ver: %s; Product Version: %s\n", + dmi_get_system_info(DMI_BIOS_VENDOR), + dmi_get_system_info(DMI_BIOS_VERSION), + dmi_get_system_info(DMI_PRODUCT_VERSION)); + return 0; + } + break; + } + + entry_header = ((void *)entry_header + entry_header->length); + } + return 1; +} + void __init detect_intel_iommu(void) { int ret; ret = dmar_table_detect(); - + if (ret) + ret = check_zero_address(); { #ifdef CONFIG_INTR_REMAP struct acpi_table_dmar *dmar; |