This is a note to let you know that I've just added the patch titled
iommu/vt-d: Fix to flush cache of PASID directory table
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-vt-d-fix-to-flush-cache-of-pasid-directory-tab.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a297e483c436356981f6dd6b1e228563e0c4401c
Author: Yanfei Xu <yanfei.xu@xxxxxxxxx>
Date: Wed Aug 9 20:48:04 2023 +0800
iommu/vt-d: Fix to flush cache of PASID directory table
[ Upstream commit 8a3b8e63f8371c1247b7aa24ff9c5312f1a6948b ]
Even the PCI devices don't support pasid capability, PASID table is
mandatory for a PCI device in scalable mode. However flushing cache
of pasid directory table for these devices are not taken after pasid
table is allocated as the "size" of table is zero. Fix it by
calculating the size by page order.
Found this when reading the code, no real problem encountered for now.
Fixes: 194b3348bdbb ("iommu/vt-d: Fix PASID directory pointer coherency")
Suggested-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Yanfei Xu <yanfei.xu@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230616081045.721873-1-yanfei.xu@xxxxxxxxx
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c
index 58f060006ba31..9641eaa19e08e 100644
--- a/drivers/iommu/intel-pasid.c
+++ b/drivers/iommu/intel-pasid.c
@@ -167,7 +167,7 @@ int intel_pasid_alloc_table(struct device *dev)
device_attach_pasid_table(info, pasid_table);
if (!ecap_coherent(info->iommu->ecap))
- clflush_cache_range(pasid_table->table, size);
+ clflush_cache_range(pasid_table->table, (1 << order) * PAGE_SIZE);
return 0;
}
