[SRU][focal:linux-gcp][PATCH 2/2] PCI: Disable ATS for specific Intel IPU E2000 devices

[Joseph Salisbury]

From: Bartosz Pawlowski <bartosz.pawlowski at intel.com>

BugLink: https://bugs.launchpad.net/bugs/2049922

Due to a hardware issue in A and B steppings of Intel IPU E2000, it expects
wrong endianness in ATS invalidation message body. This problem can lead to
outdated translations being returned as valid and finally cause system
instability.

To prevent such issues, add quirk_intel_e2000_no_ats() to disable ATS for
vulnerable IPU E2000 devices.

Link: https://lore.kernel.org/r/20230908143606.685930-3-bartosz.pawlowski@intel.com
Signed-off-by: Bartosz Pawlowski <bartosz.pawlowski at intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin at intel.com>
(backported from commit a18615b1cfc04f00548c60eb9a77e0ce56e848fd)
[jsalisbury: Resolved context diff.]
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 drivers/pci/quirks.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 088e2f3bc16f..09d1803075dc 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5454,6 +5454,24 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x7312, quirk_amd_harvest_no_ats);
 /* AMD Navi14 dGPU */
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x7340, quirk_amd_harvest_no_ats);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x7341, quirk_amd_harvest_no_ats);
+/*
+ * Intel IPU E2000 revisions before C0 implement incorrect endianness
+ * in ATS Invalidate Request message body. Disable ATS for those devices.
+ */
+static void quirk_intel_e2000_no_ats(struct pci_dev *pdev)
+{
+	if (pdev->revision < 0x20)
+		quirk_no_ats(pdev);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1451, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1452, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1453, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1454, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1455, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1457, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1459, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x145a, quirk_intel_e2000_no_ats);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x145c, quirk_intel_e2000_no_ats);
 #endif /* CONFIG_PCI_ATS */
 
 /* Freescale PCIe doesn't support MSI in RC mode */
-- 
2.34.1