drm/buddy: Add start address support to trim function

- Add a new start parameter in trim function to specify exact
  address from where to start the trimming. This would help us
  in situations like if drivers would like to do address alignment
  for specific requirements.

- Add a new flag DRM_BUDDY_TRIM_DISABLE. Drivers can use this
  flag to disable the allocator trimming part. This patch enables
  the drivers control trimming and they can do it themselves
  based on the application requirements.

v1:(Matthew)
  - check new_start alignment with min chunk_size
  - use range_overflows()

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit db65eb46de135338d6177f8853e0fd208f19d63e)

diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 6a8e45e9d0ecc19a232d489af91fc2464fff9975..103c185bb1c8a76ac0fc7a45ce2a5f34c683298a 100644 (file)
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -851,6 +851,7 @@ static int __alloc_contig_try_harder(struct drm_buddy *mm,
  * drm_buddy_block_trim - free unused pages
  *
  * @mm: DRM buddy manager
+ * @start: start address to begin the trimming.
  * @new_size: original size requested
  * @blocks: Input and output list of allocated blocks.
  * MUST contain single block as input to be trimmed.
@@ -866,11 +867,13 @@ static int __alloc_contig_try_harder(struct drm_buddy *mm,
  * 0 on success, error code on failure.
  */
 int drm_buddy_block_trim(struct drm_buddy *mm,
+                        u64 *start,
                         u64 new_size,
                         struct list_head *blocks)
 {
        struct drm_buddy_block *parent;
        struct drm_buddy_block *block;
+       u64 block_start, block_end;
        LIST_HEAD(dfs);
        u64 new_start;
        int err;
@@ -882,6 +885,9 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
                                 struct drm_buddy_block,
                                 link);
 
+       block_start = drm_buddy_block_offset(block);
+       block_end = block_start + drm_buddy_block_size(mm, block);
+
        if (WARN_ON(!drm_buddy_block_is_allocated(block)))
                return -EINVAL;
 
@@ -894,6 +900,20 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
        if (new_size == drm_buddy_block_size(mm, block))
                return 0;
 
+       new_start = block_start;
+       if (start) {
+               new_start = *start;
+
+               if (new_start < block_start)
+                       return -EINVAL;
+
+               if (!IS_ALIGNED(new_start, mm->chunk_size))
+                       return -EINVAL;
+
+               if (range_overflows(new_start, new_size, block_end))
+                       return -EINVAL;
+       }
+
        list_del(&block->link);
        mark_free(mm, block);
        mm->avail += drm_buddy_block_size(mm, block);
@@ -904,7 +924,6 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
        parent = block->parent;
        block->parent = NULL;
 
-       new_start = drm_buddy_block_offset(block);
        list_add(&block->tmp_link, &dfs);
        err =  __alloc_range(mm, &dfs, new_start, new_size, blocks, NULL);
        if (err) {
@@ -1066,7 +1085,8 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
        } while (1);
 
        /* Trim the allocated block to the required size */
-       if (original_size != size) {
+       if (!(flags & DRM_BUDDY_TRIM_DISABLE) &&
+           original_size != size) {
                struct list_head *trim_list;
                LIST_HEAD(temp);
                u64 trim_size;
@@ -1083,6 +1103,7 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
                }
 
                drm_buddy_block_trim(mm,
+                                    NULL,
                                     trim_size,
                                     trim_list);
 

diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
index fe3779fdba2c86250d3d23106888c215e034f617..423b261ea7430533ba3986df29fba3c7d54dc6f0 100644 (file)
--- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
+++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
@@ -150,7 +150,7 @@ static int xe_ttm_vram_mgr_new(struct ttm_resource_manager *man,
        } while (remaining_size);
 
        if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
-               if (!drm_buddy_block_trim(mm, vres->base.size, &vres->blocks))
+               if (!drm_buddy_block_trim(mm, NULL, vres->base.size, &vres->blocks))
                        size = vres->base.size;
        }
 

diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
index 2a74fa9d0ce554831bb3fa43b79a8a17aec91562..9689a7c5dd36b25d7ddefa0ec9fd4de210349829 100644 (file)
--- a/include/drm/drm_buddy.h
+++ b/include/drm/drm_buddy.h
@@ -27,6 +27,7 @@
 #define DRM_BUDDY_CONTIGUOUS_ALLOCATION                BIT(2)
 #define DRM_BUDDY_CLEAR_ALLOCATION             BIT(3)
 #define DRM_BUDDY_CLEARED                      BIT(4)
+#define DRM_BUDDY_TRIM_DISABLE                 BIT(5)
 
 struct drm_buddy_block {
 #define DRM_BUDDY_HEADER_OFFSET GENMASK_ULL(63, 12)
@@ -155,6 +156,7 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
                           unsigned long flags);
 
 int drm_buddy_block_trim(struct drm_buddy *mm,
+                        u64 *start,
                         u64 new_size,
                         struct list_head *blocks);