From: Matthew Auld matthew.auld@intel.com
[ Upstream commit 8d905254162965c8e6be697d82c7dbf5d08f574d ]
Crucible + recent Mesa seems to sometimes hit:
GEM_BUG_ON(num_ccs_blks > NUM_CCS_BLKS_PER_XFER)
And it looks like we can also trigger this with gem_lmem_swapping, if we modify the test to use slightly larger object sizes.
Looking closer it looks like we have the following issues in migrate_copy():
- We are using plain integer in various places, which we can easily overflow with a large object.
- We pass the entire object size (when the src is lmem) into emit_pte() and then try to copy it, which doesn't work, since we only have a few fixed sized windows in which to map the pages and perform the copy. With an object > 8M we therefore aren't properly copying the pages. And then with an object > 64M we trigger the GEM_BUG_ON(num_ccs_blks > NUM_CCS_BLKS_PER_XFER).
So it looks like our copy handling for any object > 8M (which is our CHUNK_SZ) is currently broken on DG2.
Fixes: da0595ae91da ("drm/i915/migrate: Evict and restore the flatccs capable lmem obj") Testcase: igt@gem_lmem_swapping Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com Cc: Ramalingam C ramalingam.c@intel.com Reviewed-by: Ramalingam Cramalingam.c@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20220805132240.442747-2-matthe... (cherry picked from commit 8676145eb2f53a9940ff70910caf0125bd8a4bc2) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/i915/gt/intel_migrate.c | 44 ++++++++++++------------- 1 file changed, 21 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c index 2b10b96b17b5b..933648cc90ff9 100644 --- a/drivers/gpu/drm/i915/gt/intel_migrate.c +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c @@ -638,9 +638,9 @@ static int emit_copy(struct i915_request *rq, return 0; }
-static int scatter_list_length(struct scatterlist *sg) +static u64 scatter_list_length(struct scatterlist *sg) { - int len = 0; + u64 len = 0;
while (sg && sg_dma_len(sg)) { len += sg_dma_len(sg); @@ -650,28 +650,26 @@ static int scatter_list_length(struct scatterlist *sg) return len; }
-static void +static int calculate_chunk_sz(struct drm_i915_private *i915, bool src_is_lmem, - int *src_sz, u32 bytes_to_cpy, u32 ccs_bytes_to_cpy) + u64 bytes_to_cpy, u64 ccs_bytes_to_cpy) { - if (ccs_bytes_to_cpy) { - if (!src_is_lmem) - /* - * When CHUNK_SZ is passed all the pages upto CHUNK_SZ - * will be taken for the blt. in Flat-ccs supported - * platform Smem obj will have more pages than required - * for main meory hence limit it to the required size - * for main memory - */ - *src_sz = min_t(int, bytes_to_cpy, CHUNK_SZ); - } else { /* ccs handling is not required */ - *src_sz = CHUNK_SZ; - } + if (ccs_bytes_to_cpy && !src_is_lmem) + /* + * When CHUNK_SZ is passed all the pages upto CHUNK_SZ + * will be taken for the blt. in Flat-ccs supported + * platform Smem obj will have more pages than required + * for main meory hence limit it to the required size + * for main memory + */ + return min_t(u64, bytes_to_cpy, CHUNK_SZ); + else + return CHUNK_SZ; }
-static void get_ccs_sg_sgt(struct sgt_dma *it, u32 bytes_to_cpy) +static void get_ccs_sg_sgt(struct sgt_dma *it, u64 bytes_to_cpy) { - u32 len; + u64 len;
do { GEM_BUG_ON(!it->sg || !sg_dma_len(it->sg)); @@ -702,12 +700,12 @@ intel_context_migrate_copy(struct intel_context *ce, { struct sgt_dma it_src = sg_sgt(src), it_dst = sg_sgt(dst), it_ccs; struct drm_i915_private *i915 = ce->engine->i915; - u32 ccs_bytes_to_cpy = 0, bytes_to_cpy; + u64 ccs_bytes_to_cpy = 0, bytes_to_cpy; enum i915_cache_level ccs_cache_level; u32 src_offset, dst_offset; u8 src_access, dst_access; struct i915_request *rq; - int src_sz, dst_sz; + u64 src_sz, dst_sz; bool ccs_is_src, overwrite_ccs; int err;
@@ -790,8 +788,8 @@ intel_context_migrate_copy(struct intel_context *ce, if (err) goto out_rq;
- calculate_chunk_sz(i915, src_is_lmem, &src_sz, - bytes_to_cpy, ccs_bytes_to_cpy); + src_sz = calculate_chunk_sz(i915, src_is_lmem, + bytes_to_cpy, ccs_bytes_to_cpy);
len = emit_pte(rq, &it_src, src_cache_level, src_is_lmem, src_offset, src_sz);