Commit e523b38e authored by David Woodhouse's avatar David Woodhouse

intel-iommu: Avoid panic() for DRHD at address zero.

If the BIOS does something obviously stupid, like claiming that the
registers for the IOMMU are at physical address zero, then print a nasty
message and abort, rather than trying to set up the IOMMU and then later
panicking.

It's becoming more and more obvious that trusting this stuff to the BIOS
was a mistake.
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 31d3568d
...@@ -173,12 +173,21 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header) ...@@ -173,12 +173,21 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header)
struct dmar_drhd_unit *dmaru; struct dmar_drhd_unit *dmaru;
int ret = 0; 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); dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
if (!dmaru) if (!dmaru)
return -ENOMEM; return -ENOMEM;
dmaru->hdr = header; dmaru->hdr = header;
drhd = (struct acpi_dmar_hardware_unit *)header;
dmaru->reg_base_addr = drhd->address; dmaru->reg_base_addr = drhd->address;
dmaru->segment = drhd->segment; dmaru->segment = drhd->segment;
dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */ dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
......
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