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| author | Robin Murphy <robin.murphy@arm.com> | 2023-06-01 18:43:33 +0200 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2023-06-08 23:00:22 +0200 |
| commit | 6833b8f2e19945a41e4d5efd8c6d9f4cae9a5b7d (patch) | |
| tree | b0db137e9f9da58d5234aeb419a97fab72d4d752 /drivers/iommu | |
| parent | iommu/arm-smmu-v3: Document nesting-related errata (diff) | |
| download | linux-6833b8f2e19945a41e4d5efd8c6d9f4cae9a5b7d.tar.xz linux-6833b8f2e19945a41e4d5efd8c6d9f4cae9a5b7d.zip | |
iommu/arm-smmu-v3: Set TTL invalidation hint better
When io-pgtable unmaps a whole table, rather than waste time walking it
to find the leaf entries to invalidate exactly, it simply expects
.tlb_flush_walk with nominal last-level granularity to invalidate any
leaf entries at higher intermediate levels as well. This works fine with
page-based invalidation, but with range commands we need to be careful
with the TTL hint - unconditionally setting it based on the given level
3 granule means that an invalidation for a level 1 table would strictly
not be required to affect level 2 block entries. It's easy to comply
with the expected behaviour by simply not setting the TTL hint for
non-leaf invalidations, so let's do that.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b409d9a17c52dc0db51faee91d92737bb7975f5b.1685637456.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index bbad54aa6c8c..bbafb9639e5a 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1898,8 +1898,13 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, /* Convert page size of 12,14,16 (log2) to 1,2,3 */ cmd->tlbi.tg = (tg - 10) / 2; - /* Determine what level the granule is at */ - cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3)); + /* + * Determine what level the granule is at. For non-leaf, io-pgtable + * assumes .tlb_flush_walk can invalidate multiple levels at once, + * so ignore the nominal last-level granule and leave TTL=0. + */ + if (cmd->tlbi.leaf) + cmd->tlbi.ttl = 4 - ((ilog2(granule) - 3) / (tg - 3)); num_pages = size >> tg; } |