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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>
This commit is contained in:
David Woodhouse 2009-11-09 22:15:15 +00:00
parent 799dd75b1a
commit 86cf898e1d
1 changed files with 39 additions and 10 deletions
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49
drivers/pci/dmar.c
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@ -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;