drm/amdgpu: revert "use more than 64KB fragment size if possible"

This reverts commit 1dcd32fb9c54334ec948a0f18174a748d6b14364.

The block size is indeed an equal match, so this can cause performance regressions.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index bc4b22c6fc088eb2f0ab9937eb84c03749c68540..06f24322e7c31bcfbb9dc867909ebe234968accb 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -878,13 +878,13 @@ static void amdgpu_vm_frag_ptes(struct amdgpu_pte_update_params   *params,
         * allocation size to the fragment size.
         */
 
-       const uint64_t frag_align = 1 << AMDGPU_LOG2_PAGES_PER_FRAG;
+       /* SI and newer are optimized for 64KB */
+       uint64_t frag_flags = AMDGPU_PTE_FRAG(AMDGPU_LOG2_PAGES_PER_FRAG);
+       uint64_t frag_align = 1 << AMDGPU_LOG2_PAGES_PER_FRAG;
 
        uint64_t frag_start = ALIGN(start, frag_align);
        uint64_t frag_end = end & ~(frag_align - 1);
 
-       uint32_t frag;
-
        /* system pages are non continuously */
        if (params->src || !(flags & AMDGPU_PTE_VALID) ||
            (frag_start >= frag_end)) {
@@ -893,10 +893,6 @@ static void amdgpu_vm_frag_ptes(struct amdgpu_pte_update_params    *params,
                return;
        }
 
-       /* use more than 64KB fragment size if possible */
-       frag = lower_32_bits(frag_start | frag_end);
-       frag = likely(frag) ? __ffs(frag) : 31;
-
        /* handle the 4K area at the beginning */
        if (start != frag_start) {
                amdgpu_vm_update_ptes(params, vm, start, frag_start,
@@ -906,7 +902,7 @@ static void amdgpu_vm_frag_ptes(struct amdgpu_pte_update_params     *params,
 
        /* handle the area in the middle */
        amdgpu_vm_update_ptes(params, vm, frag_start, frag_end, dst,
-                             flags | AMDGPU_PTE_FRAG(frag));
+                             flags | frag_flags);
 
        /* handle the 4K area at the end */
        if (frag_end != end) {