[PATCH 02/13] iommu/vt-d: Disable superpage for Broxton igfx

Ville Syrjala ville.syrjala at linux.intel.com
Wed Jul 7 19:56:57 UTC 2021


From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Broxton has known issues with VT-d superpage. Namely frame buffer
compression (FBC) can't be safely used when superpage is enabled.
Currently we're disabling FBC entirely when VT-d is active, but
I think just disabling superpage would be better since FBC can
save some power.

TODO: might be nice to disable superpage only for the igfx iommu
      instead of both iommus

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/iommu/intel/iommu.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 4fff2c9c86af..40117f868761 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5623,6 +5623,13 @@ static void quirk_iommu_nosp(struct pci_dev *dev)
 	intel_iommu_superpage = 0;
 }
 
+/* Broxton igfx has issues with superpage */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0A84, quirk_iommu_nosp);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1A84, quirk_iommu_nosp);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1A85, quirk_iommu_nosp);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x5A84, quirk_iommu_nosp);
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x5A85, quirk_iommu_nosp);
+
 /* Geminilake igfx appears to have issues with superpage */
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3184, quirk_iommu_nosp);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3185, quirk_iommu_nosp);
-- 
2.31.1



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