diff options
author | Robin Murphy <robin.murphy@arm.com> | 2022-11-08 20:06:19 +0300 |
---|---|---|
committer | Steven Price <steven.price@arm.com> | 2022-11-09 17:17:39 +0300 |
commit | f352262f727215553879705bacbcb208979f3eff (patch) | |
tree | 0d87abb0e00a47d3c71c4d791dab2dec959edd02 | |
parent | e0b26b9482461e9528552f54fa662c2269f75b3f (diff) |
drm/panfrost: Split io-pgtable requests properly
Although we don't use 1GB block mappings, we still need to split
map/unmap requests at 1GB boundaries to match what io-pgtable expects.
Fix that, and add some explanation to make sense of it all.
Fixes: 3740b081795a ("drm/panfrost: Update io-pgtable API")
Reported-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/49e54bb4019cd06e01549b106d7ac37c3d182cd3.1667927179.git.robin.murphy@arm.com
-rw-r--r-- | drivers/gpu/drm/panfrost/panfrost_mmu.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index e246d914e7f6..4e83a1891f3e 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -250,13 +250,22 @@ void panfrost_mmu_reset(struct panfrost_device *pfdev) static size_t get_pgsize(u64 addr, size_t size, size_t *count) { + /* + * io-pgtable only operates on multiple pages within a single table + * entry, so we need to split at boundaries of the table size, i.e. + * the next block size up. The distance from address A to the next + * boundary of block size B is logically B - A % B, but in unsigned + * two's complement where B is a power of two we get the equivalence + * B - A % B == (B - A) % B == (n * B - A) % B, and choose n = 0 :) + */ size_t blk_offset = -addr % SZ_2M; if (blk_offset || size < SZ_2M) { *count = min_not_zero(blk_offset, size) / SZ_4K; return SZ_4K; } - *count = size / SZ_2M; + blk_offset = -addr % SZ_1G ?: SZ_1G; + *count = min(blk_offset, size) / SZ_2M; return SZ_2M; } |