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authorJoerg Roedel <joerg.roedel@amd.com>2012-10-16 14:52:51 +0200
committerJoerg Roedel <joerg.roedel@amd.com>2012-10-16 14:52:51 +0200
commitc2ff5cf5294bcbd7fa50f7d860e90a66db7e5059 (patch)
tree2ec5e407ddd6cd4bb563b41f8c7d5026c4a3358c /drivers/iommu/amd_iommu_init.c
parentddffeb8c4d0331609ef2581d84de4d763607bd37 (diff)
downloadlinux-next-c2ff5cf5294bcbd7fa50f7d860e90a66db7e5059.tar.gz
iommu/amd: Work around wrong IOAPIC device-id in IVRS table
On some systems the BIOS puts the wrong device-id for the IO-APIC into the IVRS table. The result is that interrupt remapping is not working for the IO-APIC irqs. This usually means a kernel panic at boot because the timer is not working. Fix this kernel panic by disabling interrupt remapping if this problem is discovered in the IVRS table. Reported-by: Andrew Oakley <andrew@ado.is-a-geek.net> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'drivers/iommu/amd_iommu_init.c')
-rw-r--r--drivers/iommu/amd_iommu_init.c39
1 files changed, 32 insertions, 7 deletions
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 18b0d99bd4d6..81837b0710a9 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1599,21 +1599,46 @@ static void __init free_on_init_error(void)
#endif
}
+/* SB IOAPIC is always on this device in AMD systems */
+#define IOAPIC_SB_DEVID ((0x00 << 8) | PCI_DEVFN(0x14, 0))
+
static bool __init check_ioapic_information(void)
{
+ bool ret, has_sb_ioapic;
int idx;
- for (idx = 0; idx < nr_ioapics; idx++) {
- int id = mpc_ioapic_id(idx);
+ has_sb_ioapic = false;
+ ret = false;
- if (get_ioapic_devid(id) < 0) {
- pr_err(FW_BUG "AMD-Vi: IO-APIC[%d] not in IVRS table\n", id);
- pr_err("AMD-Vi: Disabling interrupt remapping due to BIOS Bug\n");
- return false;
+ for (idx = 0; idx < nr_ioapics; idx++) {
+ int devid, id = mpc_ioapic_id(idx);
+
+ devid = get_ioapic_devid(id);
+ if (devid < 0) {
+ pr_err(FW_BUG "AMD-Vi: IOAPIC[%d] not in IVRS table\n", id);
+ ret = false;
+ } else if (devid == IOAPIC_SB_DEVID) {
+ has_sb_ioapic = true;
+ ret = true;
}
}
- return true;
+ if (!has_sb_ioapic) {
+ /*
+ * We expect the SB IOAPIC to be listed in the IVRS
+ * table. The system timer is connected to the SB IOAPIC
+ * and if we don't have it in the list the system will
+ * panic at boot time. This situation usually happens
+ * when the BIOS is buggy and provides us the wrong
+ * device id for the IOAPIC in the system.
+ */
+ pr_err(FW_BUG "AMD-Vi: No southbridge IOAPIC found in IVRS table\n");
+ }
+
+ if (!ret)
+ pr_err("AMD-Vi: Disabling interrupt remapping due to BIOS Bug(s)\n");
+
+ return ret;
}
static void __init free_dma_resources(void)