[PATCH] drm/i915/ttm: fix 32b build

Matthew Auld matthew.auld at intel.com
Tue Jul 12 17:40:50 UTC 2022


Since segment_pages is no longer a compile time constant, it looks the
DIV_ROUND_UP(node->size, segment_pages) breaks the 32b build. Simplest
is just to use the ULL variant, but really we should need not need more
than u32 for the page alignment (also we are limited by that due to the
sg->length type), so also make it all u32.

Reported-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Fixes: bc99f1209f19 ("drm/i915/ttm: fix sg_table construction")
Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Nirmoy Das <nirmoy.das at linux.intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_region.c |  2 ++
 drivers/gpu/drm/i915/gem/i915_gem_ttm.c    |  2 +-
 drivers/gpu/drm/i915/i915_scatterlist.c    | 16 ++++++++--------
 drivers/gpu/drm/i915/i915_scatterlist.h    |  4 ++--
 drivers/gpu/drm/i915/intel_region_ttm.c    |  2 +-
 drivers/gpu/drm/i915/intel_region_ttm.h    |  2 +-
 6 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c
index f46ee16a323a..a4fb577eceb4 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c
@@ -60,6 +60,8 @@ __i915_gem_object_create_region(struct intel_memory_region *mem,
 	if (page_size)
 		default_page_size = page_size;
 
+	/* We should be able to fit a page within an sg entry */
+	GEM_BUG_ON(overflows_type(default_page_size, u32));
 	GEM_BUG_ON(!is_power_of_2_u64(default_page_size));
 	GEM_BUG_ON(default_page_size < PAGE_SIZE);
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 053b0022ddd0..5a5cf332d8a5 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -602,7 +602,7 @@ i915_ttm_resource_get_st(struct drm_i915_gem_object *obj,
 			 struct ttm_resource *res)
 {
 	struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
-	u64 page_alignment;
+	u32 page_alignment;
 
 	if (!i915_ttm_gtt_binds_lmem(res))
 		return i915_ttm_tt_get_st(bo->ttm);
diff --git a/drivers/gpu/drm/i915/i915_scatterlist.c b/drivers/gpu/drm/i915/i915_scatterlist.c
index f63b50b71e10..dcc081874ec8 100644
--- a/drivers/gpu/drm/i915/i915_scatterlist.c
+++ b/drivers/gpu/drm/i915/i915_scatterlist.c
@@ -79,10 +79,10 @@ void i915_refct_sgt_init(struct i915_refct_sgt *rsgt, size_t size)
  */
 struct i915_refct_sgt *i915_rsgt_from_mm_node(const struct drm_mm_node *node,
 					      u64 region_start,
-					      u64 page_alignment)
+					      u32 page_alignment)
 {
-	const u64 max_segment = round_down(UINT_MAX, page_alignment);
-	u64 segment_pages = max_segment >> PAGE_SHIFT;
+	const u32 max_segment = round_down(UINT_MAX, page_alignment);
+	const u32 segment_pages = max_segment >> PAGE_SHIFT;
 	u64 block_size, offset, prev_end;
 	struct i915_refct_sgt *rsgt;
 	struct sg_table *st;
@@ -96,7 +96,7 @@ struct i915_refct_sgt *i915_rsgt_from_mm_node(const struct drm_mm_node *node,
 
 	i915_refct_sgt_init(rsgt, node->size << PAGE_SHIFT);
 	st = &rsgt->table;
-	if (sg_alloc_table(st, DIV_ROUND_UP(node->size, segment_pages),
+	if (sg_alloc_table(st, DIV_ROUND_UP_ULL(node->size, segment_pages),
 			   GFP_KERNEL)) {
 		i915_refct_sgt_put(rsgt);
 		return ERR_PTR(-ENOMEM);
@@ -123,7 +123,7 @@ struct i915_refct_sgt *i915_rsgt_from_mm_node(const struct drm_mm_node *node,
 			st->nents++;
 		}
 
-		len = min(block_size, max_segment - sg->length);
+		len = min_t(u64, block_size, max_segment - sg->length);
 		sg->length += len;
 		sg_dma_len(sg) += len;
 
@@ -155,11 +155,11 @@ struct i915_refct_sgt *i915_rsgt_from_mm_node(const struct drm_mm_node *node,
  */
 struct i915_refct_sgt *i915_rsgt_from_buddy_resource(struct ttm_resource *res,
 						     u64 region_start,
-						     u64 page_alignment)
+						     u32 page_alignment)
 {
 	struct i915_ttm_buddy_resource *bman_res = to_ttm_buddy_resource(res);
 	const u64 size = res->num_pages << PAGE_SHIFT;
-	const u64 max_segment = round_down(UINT_MAX, page_alignment);
+	const u32 max_segment = round_down(UINT_MAX, page_alignment);
 	struct drm_buddy *mm = bman_res->mm;
 	struct list_head *blocks = &bman_res->blocks;
 	struct drm_buddy_block *block;
@@ -207,7 +207,7 @@ struct i915_refct_sgt *i915_rsgt_from_buddy_resource(struct ttm_resource *res,
 				st->nents++;
 			}
 
-			len = min(block_size, max_segment - sg->length);
+			len = min_t(u64, block_size, max_segment - sg->length);
 			sg->length += len;
 			sg_dma_len(sg) += len;
 
diff --git a/drivers/gpu/drm/i915/i915_scatterlist.h b/drivers/gpu/drm/i915/i915_scatterlist.h
index b13e4cdea923..9ddb3e743a3e 100644
--- a/drivers/gpu/drm/i915/i915_scatterlist.h
+++ b/drivers/gpu/drm/i915/i915_scatterlist.h
@@ -214,10 +214,10 @@ void i915_refct_sgt_init(struct i915_refct_sgt *rsgt, size_t size);
 
 struct i915_refct_sgt *i915_rsgt_from_mm_node(const struct drm_mm_node *node,
 					      u64 region_start,
-					      u64 page_alignment);
+					      u32 page_alignment);
 
 struct i915_refct_sgt *i915_rsgt_from_buddy_resource(struct ttm_resource *res,
 						     u64 region_start,
-						     u64 page_alignment);
+						     u32 page_alignment);
 
 #endif
diff --git a/drivers/gpu/drm/i915/intel_region_ttm.c b/drivers/gpu/drm/i915/intel_region_ttm.c
index 6873808a7015..575d67bc6ffe 100644
--- a/drivers/gpu/drm/i915/intel_region_ttm.c
+++ b/drivers/gpu/drm/i915/intel_region_ttm.c
@@ -163,7 +163,7 @@ int intel_region_ttm_fini(struct intel_memory_region *mem)
 struct i915_refct_sgt *
 intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
 				  struct ttm_resource *res,
-				  u64 page_alignment)
+				  u32 page_alignment)
 {
 	if (mem->is_range_manager) {
 		struct ttm_range_mgr_node *range_node =
diff --git a/drivers/gpu/drm/i915/intel_region_ttm.h b/drivers/gpu/drm/i915/intel_region_ttm.h
index 98fba5155619..5bb8d8b582ae 100644
--- a/drivers/gpu/drm/i915/intel_region_ttm.h
+++ b/drivers/gpu/drm/i915/intel_region_ttm.h
@@ -25,7 +25,7 @@ int intel_region_ttm_fini(struct intel_memory_region *mem);
 struct i915_refct_sgt *
 intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
 				  struct ttm_resource *res,
-				  u64 page_alignment);
+				  u32 page_alignment);
 
 void intel_region_ttm_resource_free(struct intel_memory_region *mem,
 				    struct ttm_resource *res);
-- 
2.36.1



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