6.16-stable review patch. If anyone has any objections, please let me know.
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From: Easwar Hariharan eahariha@linux.microsoft.com
[ Upstream commit c694bc8b612ddd0dd70e122a00f39cb1e2e6927f ]
Per the PCIe spec, behavior of the PASID capability is undefined if the value of the PASID Enable bit changes while the Enable bit of the function's ATS control register is Set. Unfortunately, pdev_enable_caps() does exactly that by ordering enabling ATS for the device before enabling PASID.
Cc: Suravee Suthikulpanit suravee.suthikulpanit@amd.com Cc: Vasant Hegde vasant.hegde@amd.com Cc: Jason Gunthorpe jgg@nvidia.com Cc: Jerry Snitselaar jsnitsel@redhat.com Fixes: eda8c2860ab679 ("iommu/amd: Enable device ATS/PASID/PRI capabilities independently") Signed-off-by: Easwar Hariharan eahariha@linux.microsoft.com Reviewed-by: Vasant Hegde vasant.hegde@amd.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Link: https://lore.kernel.org/r/20250703155433.6221-1-eahariha@linux.microsoft.com Signed-off-by: Joerg Roedel joerg.roedel@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/amd/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 3117d99cf83d..8b8d3e843743 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -634,8 +634,8 @@ static inline void pdev_disable_cap_pasid(struct pci_dev *pdev)
static void pdev_enable_caps(struct pci_dev *pdev) { - pdev_enable_cap_ats(pdev); pdev_enable_cap_pasid(pdev); + pdev_enable_cap_ats(pdev); pdev_enable_cap_pri(pdev); }