Ankit Soni 715c263119 iommu/amd: move wait_on_sem() out of spinlock ...

[ Upstream commit d2a0cac105 ]

With iommu.strict=1, the existing completion wait path can cause soft
lockups under stressed environment, as wait_on_sem() busy-waits under the
spinlock with interrupts disabled.

Move the completion wait in iommu_completion_wait() out of the spinlock.
wait_on_sem() only polls the hardware-updated cmd_sem and does not require
iommu->lock, so holding the lock during the busy wait unnecessarily
increases contention and extends the time with interrupts disabled.

Signed-off-by: Ankit Soni <Ankit.Soni@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2026-03-04 07:21:12 -05:00

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amd_iommu_types.h

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amd_iommu.h

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debugfs.c

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init.c

Revert "iommu/amd: Skip enabling command/event buffers for kdump"

2026-01-11 15:25:21 +01:00

io_pgtable_v2.c

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io_pgtable.c

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iommu.c

iommu/amd: move wait_on_sem() out of spinlock

2026-03-04 07:21:12 -05:00

Kconfig

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Makefile

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pasid.c

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ppr.c

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quirks.c

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