From: Vasant Hegde <vasant.hegde@amd.com>
To: <iommu@lists.linux.dev>, <joro@8bytes.org>
Cc: <suravee.suthikulpanit@amd.com>, <wei.huang2@amd.com>,
<jsnitsel@redhat.com>, <jgg@ziepe.ca>,
Vasant Hegde <vasant.hegde@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: [PATCH v4 05/14] iommu/amd: Fix PPR interrupt processing logic
Date: Thu, 21 Dec 2023 11:15:49 +0000 [thread overview]
Message-ID: <20231221111558.64652-6-vasant.hegde@amd.com> (raw)
In-Reply-To: <20231221111558.64652-1-vasant.hegde@amd.com>
* 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: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
---
drivers/iommu/amd/ppr.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/iommu/amd/ppr.c b/drivers/iommu/amd/ppr.c
index 673fcc30f9dc..d43a616c0c36 100644
--- a/drivers/iommu/amd/ppr.c
+++ b/drivers/iommu/amd/ppr.c
@@ -104,9 +104,5 @@ 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);
}
}
--
2.31.1
next prev parent reply other threads:[~2023-12-21 11:17 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 11:15 [PATCH v4 00/14] iommu/amd: SVA Support (Part 4) - SVA and IOPF Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 01/14] iommu/amd: Rename amd_iommu_v2_supported() as amd_iommu_pasid_supported() Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 02/14] iommu/amd: Introduce per device DTE update function Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 03/14] iommu/amd: Add support for enabling/disabling IOMMU features Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 04/14] iommu/amd: Move PPR-related functions into ppr.c Vasant Hegde
2023-12-21 11:15 ` Vasant Hegde [this message]
2023-12-21 11:15 ` [PATCH v4 06/14] iommu/amd: Define per-IOMMU iopf_queue Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 07/14] iommu/amd: Add support for page response Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 08/14] iommu/amd: Add support for add/remove device for IOPF Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 09/14] iommu/amd: Add IO page fault notifier handler Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 10/14] iommu/amd: Introduce logic to enable/disable IOPF Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 11/14] iommu/amd: Add GCR3 [un]initialization function Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 12/14] iommu/amd: Initial SVA support for AMD IOMMU Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 13/14] iommu: Add ops->domain_alloc_sva() Vasant Hegde
2024-01-08 6:46 ` Tina Zhang
2024-01-09 17:50 ` Jason Gunthorpe
2024-01-11 5:18 ` Vasant Hegde
2023-12-21 11:15 ` [PATCH v4 14/14] iommu/amd: Add SVA domain support Vasant Hegde
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231221111558.64652-6-vasant.hegde@amd.com \
--to=vasant.hegde@amd.com \
--cc=iommu@lists.linux.dev \
--cc=jgg@ziepe.ca \
--cc=joro@8bytes.org \
--cc=jsnitsel@redhat.com \
--cc=suravee.suthikulpanit@amd.com \
--cc=thomas.lendacky@amd.com \
--cc=wei.huang2@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox