diff options
| author | Will Deacon <will@kernel.org> | 2019-07-02 18:43:24 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2019-07-24 15:32:33 +0300 |
| commit | f71da46719460acd5afa411e52dc8cdf1cb9b0ce (patch) | |
| tree | 3a4fed5a63fbc6fe7a3700f5e8adae1e0a475541 | |
| parent | 6d1bcb957be2850e0776f24c289e1f87c256baeb (diff) | |
| download | linux-f71da46719460acd5afa411e52dc8cdf1cb9b0ce.tar.xz | |
iommu/io-pgtable-arm: Remove redundant call to io_pgtable_tlb_sync()
Commit b6b65ca20bc9 ("iommu/io-pgtable-arm: Add support for non-strict
mode") added an unconditional call to io_pgtable_tlb_sync() immediately
after the case where we replace a block entry with a table entry during
an unmap() call. This is redundant, since the IOMMU API will call
iommu_tlb_sync() on this path and the patch in question mentions this:
| To save having to reason about it too much, make sure the invalidation
| in arm_lpae_split_blk_unmap() just performs its own unconditional sync
| to minimise the window in which we're technically violating the break-
| before-make requirement on a live mapping. This might work out redundant
| with an outer-level sync for strict unmaps, but we'll never be splitting
| blocks on a DMA fastpath anyway.
However, this sync gets in the way of deferred TLB invalidation for leaf
entries and is at best a questionable, unproven hack. Remove it.
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | drivers/iommu/io-pgtable-arm-v7s.c | 1 | ||||
| -rw-r--r-- | drivers/iommu/io-pgtable-arm.c | 1 |
2 files changed, 0 insertions, 2 deletions
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index 0fc8dfab2abf..a62733c6a632 100644 --- a/drivers/iommu/io-pgtable-arm-v7s.c +++ b/drivers/iommu/io-pgtable-arm-v7s.c @@ -587,7 +587,6 @@ static size_t arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data, } io_pgtable_tlb_add_flush(&data->iop, iova, size, size, true); - io_pgtable_tlb_sync(&data->iop); return size; } diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 161a7d56264d..0d6633921c1e 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -583,7 +583,6 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data, tablep = iopte_deref(pte, data); } else if (unmap_idx >= 0) { io_pgtable_tlb_add_flush(&data->iop, iova, size, size, true); - io_pgtable_tlb_sync(&data->iop); return size; } |