adulau/aha
1
0
Fork 0
mirror of https://github.com/adulau/aha.git synced 2024-12-27 19:26:25 +00:00
Code Issues Projects Releases Packages Wiki Activity

intel-iommu: Detect DMAR in hyperspace at probe time.

Browse source 
Many BIOSes will lie to us about the existence of an IOMMU, and claim
that there is one at an address which actually returns all 0xFF.

We need to detect this early, so that we know we don't have a viable
IOMMU and can set up swiotlb before it's too late.

Cc: stable@kernel.org
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Chris Wright 2009-12-02 09:17:13 +00:00 committed by David Woodhouse
parent ec20849193
commit 2c99220810
1 changed files with 29 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

34
drivers/pci/dmar.c
View file

@ -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)