x86/amd-iommu: Work around S3 BIOS bug

This patch adds a workaround for an IOMMU BIOS problem to
the AMD IOMMU driver. The result of the bug is that the
IOMMU does not execute commands anymore when the system
comes out of the S3 state resulting in system failure. The
bug in the BIOS is that is does not restore certain hardware
specific registers correctly. This workaround reads out the
contents of these registers at boot time and restores them
on resume from S3. The workaround is limited to the specific
IOMMU chipset where this problem occurs.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 10d33309e9a6..570fddeb0388 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -393,6 +393,9 @@
 #define PCI_DEVICE_ID_VLSI_82C147       0x0105
 #define PCI_DEVICE_ID_VLSI_VAS96011     0x0702
 
+/* AMD RD890 Chipset */
+#define PCI_DEVICE_ID_RD890_IOMMU       0x5a23
+
 #define PCI_VENDOR_ID_ADL               0x1005
 #define PCI_DEVICE_ID_ADL_2301          0x2301