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: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 25a00ce..fa3a113 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -173,12 +173,21 @@
struct dmar_drhd_unit *dmaru;
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;
dmaru->hdr = header;
- drhd = (struct acpi_dmar_hardware_unit *)header;
dmaru->reg_base_addr = drhd->address;
dmaru->segment = drhd->segment;
dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */