Commit 7c5b7176 authored by Vasant Hegde's avatar Vasant Hegde Committed by Joerg Roedel
Browse files

iommu/amd: Fix PPR interrupt processing logic 



* Do not re-read ppr head pointer as its just updated by the driver.

* Do not read PPR buffer tail pointer inside while loop. If IOMMU
  generates PPR events continuously then completing interrupt processing
  takes long time. In worst case it may cause infinite loop.

Suggested-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarVasant Hegde <vasant.hegde@amd.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240418103400.6229-6-vasant.hegde@amd.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent e08fcd90

drivers/iommu/amd/ppr.c

+0 −4
Original line number Diff line number Diff line
@@ -106,9 +106,5 @@ void amd_iommu_poll_ppr_log(struct amd_iommu *iommu) 
		writel(head, iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);



		/* TODO: PPR Handler will be added when we add IOPF support */



		/* Refresh ring-buffer information */

		head = readl(iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);

		tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET);

	}

}