This iterator relies on drm_mm_first_hole() and drm_mm_next_hole() functions to identify suitable holes for an allocation of a given size by efficiently traversing the rbtree associated with the given allocator.
It replaces the for loop in drm_mm_insert_node_in_range() and can also be used by drm drivers to quickly identify holes of a certain size within a given range.
v2: (Tvrtko) - Prepend a double underscore for the newly exported first/next_hole - s/each_best_hole/each_suitable_hole/g - Mask out DRM_MM_INSERT_ONCE from the mode before calling first/next_hole and elsewhere.
v3: (Tvrtko) - Reduce the number of hunks by retaining the "mode" variable name
v4: - Typo: s/__drm_mm_next_hole(.., hole/__drm_mm_next_hole(.., pos
Reviewed-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Acked-by: Christian König christian.koenig@amd.com Suggested-by: Tvrtko Ursulin tvrtko.ursulin@linux.intel.com Signed-off-by: Vivek Kasireddy vivek.kasireddy@intel.com --- drivers/gpu/drm/drm_mm.c | 32 +++++++++++++++----------------- include/drm/drm_mm.h | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 499d8874e4ed..f5339610361c 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -352,10 +352,10 @@ static struct drm_mm_node *find_hole_addr(struct drm_mm *mm, u64 addr, u64 size) return node; }
-static struct drm_mm_node * -first_hole(struct drm_mm *mm, - u64 start, u64 end, u64 size, - enum drm_mm_insert_mode mode) +struct drm_mm_node * +__drm_mm_first_hole(struct drm_mm *mm, + u64 start, u64 end, u64 size, + enum drm_mm_insert_mode mode) { switch (mode) { default: @@ -374,6 +374,7 @@ first_hole(struct drm_mm *mm, hole_stack); } } +EXPORT_SYMBOL(__drm_mm_first_hole);
/** * DECLARE_NEXT_HOLE_ADDR - macro to declare next hole functions @@ -411,11 +412,11 @@ static struct drm_mm_node *name(struct drm_mm_node *entry, u64 size) \ DECLARE_NEXT_HOLE_ADDR(next_hole_high_addr, rb_left, rb_right) DECLARE_NEXT_HOLE_ADDR(next_hole_low_addr, rb_right, rb_left)
-static struct drm_mm_node * -next_hole(struct drm_mm *mm, - struct drm_mm_node *node, - u64 size, - enum drm_mm_insert_mode mode) +struct drm_mm_node * +__drm_mm_next_hole(struct drm_mm *mm, + struct drm_mm_node *node, + u64 size, + enum drm_mm_insert_mode mode) { switch (mode) { default: @@ -433,6 +434,7 @@ next_hole(struct drm_mm *mm, return &node->hole_stack == &mm->hole_stack ? NULL : node; } } +EXPORT_SYMBOL(__drm_mm_next_hole);
/** * drm_mm_reserve_node - insert an pre-initialized node @@ -517,11 +519,11 @@ int drm_mm_insert_node_in_range(struct drm_mm * const mm, u64 size, u64 alignment, unsigned long color, u64 range_start, u64 range_end, - enum drm_mm_insert_mode mode) + enum drm_mm_insert_mode caller_mode) { struct drm_mm_node *hole; u64 remainder_mask; - bool once; + enum drm_mm_insert_mode mode = caller_mode & ~DRM_MM_INSERT_ONCE;
DRM_MM_BUG_ON(range_start > range_end);
@@ -534,13 +536,9 @@ int drm_mm_insert_node_in_range(struct drm_mm * const mm, if (alignment <= 1) alignment = 0;
- once = mode & DRM_MM_INSERT_ONCE; - mode &= ~DRM_MM_INSERT_ONCE; - remainder_mask = is_power_of_2(alignment) ? alignment - 1 : 0; - for (hole = first_hole(mm, range_start, range_end, size, mode); - hole; - hole = once ? NULL : next_hole(mm, hole, size, mode)) { + drm_mm_for_each_suitable_hole(hole, mm, range_start, range_end, + size, mode) { u64 hole_start = __drm_mm_hole_node_start(hole); u64 hole_end = hole_start + hole->hole_size; u64 adj_start, adj_end; diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h index ac33ba1b18bc..dff6db627807 100644 --- a/include/drm/drm_mm.h +++ b/include/drm/drm_mm.h @@ -400,6 +400,42 @@ static inline u64 drm_mm_hole_node_end(const struct drm_mm_node *hole_node) 1 : 0; \ pos = list_next_entry(pos, hole_stack))
+struct drm_mm_node * +__drm_mm_first_hole(struct drm_mm *mm, + u64 start, u64 end, u64 size, + enum drm_mm_insert_mode mode); + +struct drm_mm_node * +__drm_mm_next_hole(struct drm_mm *mm, + struct drm_mm_node *node, + u64 size, + enum drm_mm_insert_mode mode); + +/** + * drm_mm_for_each_suitable_hole - iterator to optimally walk over all + * holes that can fit an allocation of the given @size. + * @pos: &drm_mm_node used internally to track progress + * @mm: &drm_mm allocator to walk + * @range_start: start of the allowed range for the allocation + * @range_end: end of the allowed range for the allocation + * @size: size of the allocation + * @mode: fine-tune the allocation search + * + * This iterator walks over all holes suitable for the allocation of given + * @size in a very efficient manner. It is implemented by calling + * drm_mm_first_hole() and drm_mm_next_hole() which identify the + * appropriate holes within the given range by efficiently traversing the + * rbtree associated with @mm. + */ +#define drm_mm_for_each_suitable_hole(pos, mm, range_start, range_end, \ + size, mode) \ + for (pos = __drm_mm_first_hole(mm, range_start, range_end, size, \ + mode & ~DRM_MM_INSERT_ONCE); \ + pos; \ + pos = mode & DRM_MM_INSERT_ONCE ? \ + NULL : __drm_mm_next_hole(mm, pos, size, \ + mode & ~DRM_MM_INSERT_ONCE)) + /* * Basic range manager support (drm_mm.c) */