[PATCH 06/13] drm/radeon: improve sub allocator

[Christian König]

Make the suballocator self containing to locking
and fix a overrun bug which happens with
allocations of different alignments.

Signed-off-by: Christian König <deathsimple at vodafone.de>
---
 drivers/gpu/drm/radeon/radeon.h    |    1 +
 drivers/gpu/drm/radeon/radeon_sa.c |   19 ++++++++++++-------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 85a3aa9..1aefbd9 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -381,6 +381,7 @@ struct radeon_bo_list {
  * alignment).
  */
 struct radeon_sa_manager {
+	spinlock_t		lock;
 	struct radeon_bo	*bo;
 	struct list_head	sa_bo;
 	unsigned		size;
diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
index 4cce47e..4ce5c51 100644
--- a/drivers/gpu/drm/radeon/radeon_sa.c
+++ b/drivers/gpu/drm/radeon/radeon_sa.c
@@ -37,6 +37,7 @@ int radeon_sa_bo_manager_init(struct radeon_device *rdev,
 {
 	int r;
 
+	spin_lock_init(&sa_manager->lock);
 	sa_manager->bo = NULL;
 	sa_manager->size = size;
 	sa_manager->domain = domain;
@@ -136,30 +137,30 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
 	struct radeon_sa_bo *tmp;
 	struct list_head *head;
 	unsigned offset = 0, wasted = 0;
+	unsigned long flags;
 
 	BUG_ON(align > RADEON_GPU_PAGE_SIZE);
 	BUG_ON(size > sa_manager->size);
+	spin_lock_irqsave(&sa_manager->lock, flags);
 
 	/* no one ? */
-	head = sa_manager->sa_bo.prev;
 	if (list_empty(&sa_manager->sa_bo)) {
+		head = &sa_manager->sa_bo;
 		goto out;
 	}
 
 	/* look for a hole big enough */
-	offset = 0;
 	list_for_each_entry(tmp, &sa_manager->sa_bo, list) {
 		/* room before this object ? */
-		if ((tmp->offset - offset) >= size) {
+		if (offset < tmp->offset && (tmp->offset - offset) >= size) {
 			head = tmp->list.prev;
 			goto out;
 		}
 		offset = tmp->offset + tmp->size;
 		wasted = offset % align;
 		if (wasted) {
-			wasted = align - wasted;
+			offset += align - wasted;
 		}
-		offset += wasted;
 	}
 	/* room at the end ? */
 	head = sa_manager->sa_bo.prev;
@@ -167,11 +168,11 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
 	offset = tmp->offset + tmp->size;
 	wasted = offset % align;
 	if (wasted) {
-		wasted = align - wasted;
+		offset += wasted = align - wasted;
 	}
-	offset += wasted;
 	if ((sa_manager->size - offset) < size) {
 		/* failed to find somethings big enough */
+		spin_unlock_irqrestore(&sa_manager->lock, flags);
 		return -ENOMEM;
 	}
 
@@ -180,10 +181,14 @@ out:
 	sa_bo->offset = offset;
 	sa_bo->size = size;
 	list_add(&sa_bo->list, head);
+	spin_unlock_irqrestore(&sa_manager->lock, flags);
 	return 0;
 }
 
 void radeon_sa_bo_free(struct radeon_device *rdev, struct radeon_sa_bo *sa_bo)
 {
+	unsigned long flags;
+	spin_lock_irqsave(&sa_bo->manager->lock, flags);
 	list_del_init(&sa_bo->list);
+	spin_unlock_irqrestore(&sa_bo->manager->lock, flags);
 }
-- 
1.7.5.4