[PATCH v2 30/40] drm: Unconditionally do the range check in drm_mm_scan_add_block()

[Chris Wilson]

Doing the check is trivial (low cost in comparison to overall eviction)
and helps simplify the code.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/drm_mm.c              | 53 +++--------------------------------
 drivers/gpu/drm/i915/i915_gem_evict.c | 10 ++-----
 include/drm/drm_mm.h                  | 33 ++++++++++++++++++----
 3 files changed, 34 insertions(+), 62 deletions(-)

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 6bb61f2212f8..04b1d36c4ebc 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -710,46 +710,6 @@ EXPORT_SYMBOL(drm_mm_replace_node);
  */
 
 /**
- * drm_mm_scan_init - initialize lru scanning
- * @scan: scan state
- * @mm: drm_mm to scan
- * @size: size of the allocation
- * @alignment: alignment of the allocation
- * @color: opaque tag value to use for the allocation
- *
- * This simply sets up the scanning routines with the parameters for the desired
- * hole. Note that there's no need to specify allocation flags, since they only
- * change the place a node is allocated from within a suitable hole.
- *
- * Warning:
- * As long as the scan list is non-empty, no other operations than
- * adding/removing nodes to/from the scan list are allowed.
- */
-void drm_mm_scan_init(struct drm_mm_scan *scan,
-		      struct drm_mm *mm,
-		      u64 size,
-		      u64 alignment,
-		      unsigned long color)
-{
-	DRM_MM_BUG_ON(size == 0);
-	DRM_MM_BUG_ON(mm->scan_active);
-
-	scan->mm = mm;
-
-	scan->color = color;
-	scan->alignment = alignment;
-	scan->size = size;
-
-	scan->check_range = 0;
-
-	scan->hit_start = U64_MAX;
-	scan->hit_end = 0;
-
-	scan->prev_scanned_node = NULL;
-}
-EXPORT_SYMBOL(drm_mm_scan_init);
-
-/**
  * drm_mm_scan_init_with_range - initialize range-restricted lru scanning
  * @scan: scan state
  * @mm: drm_mm to scan
@@ -788,7 +748,6 @@ void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
 	DRM_MM_BUG_ON(end <= start);
 	scan->range_start = start;
 	scan->range_end = end;
-	scan->check_range = 1;
 
 	scan->hit_start = U64_MAX;
 	scan->hit_end = 0;
@@ -830,15 +789,11 @@ bool drm_mm_scan_add_block(struct drm_mm_scan *scan,
 	node->node_list.next = &scan->prev_scanned_node->node_list;
 	scan->prev_scanned_node = node;
 
-	adj_start = hole_start = drm_mm_hole_node_start(hole);
-	adj_end = hole_end = drm_mm_hole_node_end(hole);
+	hole_start = drm_mm_hole_node_start(hole);
+	hole_end = drm_mm_hole_node_end(hole);
 
-	if (scan->check_range) {
-		if (adj_start < scan->range_start)
-			adj_start = scan->range_start;
-		if (adj_end > scan->range_end)
-			adj_end = scan->range_end;
-	}
+	adj_start = max(hole_start, scan->range_start);
+	adj_end = min(hole_end, scan->range_end);
 
 	if (mm->color_adjust)
 		mm->color_adjust(hole, scan->color, &adj_start, &adj_end);
diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index 6db0d73c0aa7..77ded288534b 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -126,13 +126,9 @@ i915_gem_evict_something(struct i915_address_space *vm,
 	 * On each list, the oldest objects lie at the HEAD with the freshest
 	 * object on the TAIL.
 	 */
-	if (start != 0 || end != vm->total) {
-		drm_mm_scan_init_with_range(&scan, &vm->mm, min_size,
-					    alignment, cache_level,
-					    start, end);
-	} else
-		drm_mm_scan_init(&scan, &vm->mm, min_size,
-				 alignment, cache_level);
+	drm_mm_scan_init_with_range(&scan, &vm->mm,
+				    min_size, alignment, cache_level,
+				    start, end);
 
 	/* Retire before we search the active list. Although we have
 	 * reasonable accuracy in our retirement lists, we may have
diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index 4db57bef98e0..8539832fac0f 100644
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -120,7 +120,6 @@ struct drm_mm_scan {
 	struct drm_mm_node *prev_scanned_node;
 
 	unsigned long color;
-	bool check_range : 1;
 };
 
 /**
@@ -375,11 +374,6 @@ __drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last);
 	     node__ && node__->start < (end__);				\
 	     node__ = list_next_entry(node__, node_list))
 
-void drm_mm_scan_init(struct drm_mm_scan *scan,
-		      struct drm_mm *mm,
-		      u64 size,
-		      u64 alignment,
-		      unsigned long color);
 void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
 				 struct drm_mm *mm,
 				 u64 size,
@@ -387,6 +381,33 @@ void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
 				 unsigned long color,
 				 u64 start,
 				 u64 end);
+
+/**
+ * drm_mm_scan_init - initialize lru scanning
+ * @scan: scan state
+ * @mm: drm_mm to scan
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @color: opaque tag value to use for the allocation
+ *
+ * This simply sets up the scanning routines with the parameters for the desired
+ * hole. Note that there's no need to specify allocation flags, since they only
+ * change the place a node is allocated from within a suitable hole.
+ *
+ * Warning:
+ * As long as the scan list is non-empty, no other operations than
+ * adding/removing nodes to/from the scan list are allowed.
+ */
+static inline void drm_mm_scan_init(struct drm_mm_scan *scan,
+				    struct drm_mm *mm,
+				    u64 size,
+				    u64 alignment,
+				    unsigned long color)
+{
+	drm_mm_scan_init_with_range(scan, mm, size, alignment, color,
+				    0, U64_MAX);
+}
+
 bool drm_mm_scan_add_block(struct drm_mm_scan *scan,
 			   struct drm_mm_node *node);
 bool drm_mm_scan_remove_block(struct drm_mm_scan *scan,
-- 
2.11.0