iommu/dma: simplify dma_iova_destroy() and drop the free_iova helper

Browse source

dma_iova_destroy() frees the IOVA space through __iommu_dma_iova_unlink()
using a "free_iova" boolean, which duplicates the IOVA free logic in
dma_iova_free(). And it frees using the unmapped @mapped_len, which for a
partially linked reservation is smaller than the reserved size. This
results in a benign waste as pointed out by Robin, not a leak. So this is
a cleanup, not a fix.

Drop the duplicated free path. Fold __iommu_dma_iova_unlink into
dma_iova_unlink and remove the free_iova parameter so it only unmaps.
dma_iova_destroy then unlinks the mapped range if mapped_len is set and
unconditionally calls dma_iova_free, which frees the whole reservation
via dma_iova_size. The freed size now always matches the reserved size,
and destroy reads as unlink then free.

Note that dma_iova_destroy() no longer routes the free through the flush
queue; teardown now unmaps synchronously and frees directly, matching
dma_iova_free().

No functional change intended for callers.

Suggested-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Honglei Huang <honghuan@amd.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260703033729.455358-1-honghuan@amd.com

...

This commit is contained in:

Honglei Huang 2026-07-03 11:37:29 +08:00 • committed by Marek Szyprowski

parent dbcc3cd580

commit 1acce29926

1 changed files with 22 additions and 35 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

69

drivers/iommu/dma-iommu.c

View file