From 44d5f3319d761d739f76b8a93b627d9dc105ec89 Mon Sep 17 00:00:00 2001
From: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Date: Tue, 15 Jan 2013 14:57:05 +0100
Subject: [PATCH] --- yaml --- r: 358160 b: refs/heads/master c:
 5e45d7dfd74100d622f9cdc70bfd1f9fae1671de h: refs/heads/master v: v3

---
 [refs]                                |  2 +-
 trunk/drivers/gpu/drm/ttm/ttm_bo.c    | 47 +++++++++++++++++++++++++++
 trunk/include/drm/ttm/ttm_bo_driver.h | 30 +++++++++++++++++
 3 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 3eb42fa1529b..0e306de62184 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7a1863084c9d90ce4b67d645bf9b0f1612e68f62
+refs/heads/master: 5e45d7dfd74100d622f9cdc70bfd1f9fae1671de
diff --git a/trunk/drivers/gpu/drm/ttm/ttm_bo.c b/trunk/drivers/gpu/drm/ttm/ttm_bo.c
index e8e4814b1295..4dd6f9e77a7d 100644
--- a/trunk/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/trunk/drivers/gpu/drm/ttm/ttm_bo.c
@@ -310,6 +310,53 @@ int ttm_bo_reserve(struct ttm_buffer_object *bo,
 	return ret;
 }
 
+int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo,
+				  bool interruptible, uint32_t sequence)
+{
+	bool wake_up = false;
+	int ret;
+
+	while (unlikely(atomic_xchg(&bo->reserved, 1) != 0)) {
+		WARN_ON(bo->seq_valid && sequence == bo->val_seq);
+
+		ret = ttm_bo_wait_unreserved(bo, interruptible);
+
+		if (unlikely(ret))
+			return ret;
+	}
+
+	if ((bo->val_seq - sequence < (1 << 31)) || !bo->seq_valid)
+		wake_up = true;
+
+	/**
+	 * Wake up waiters that may need to recheck for deadlock,
+	 * if we decreased the sequence number.
+	 */
+	bo->val_seq = sequence;
+	bo->seq_valid = true;
+	if (wake_up)
+		wake_up_all(&bo->event_queue);
+
+	return 0;
+}
+
+int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
+			    bool interruptible, uint32_t sequence)
+{
+	struct ttm_bo_global *glob = bo->glob;
+	int put_count, ret;
+
+	ret = ttm_bo_reserve_slowpath_nolru(bo, interruptible, sequence);
+	if (likely(!ret)) {
+		spin_lock(&glob->lru_lock);
+		put_count = ttm_bo_del_from_lru(bo);
+		spin_unlock(&glob->lru_lock);
+		ttm_bo_list_ref_sub(bo, put_count, true);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(ttm_bo_reserve_slowpath);
+
 void ttm_bo_unreserve_locked(struct ttm_buffer_object *bo)
 {
 	ttm_bo_add_to_lru(bo);
diff --git a/trunk/include/drm/ttm/ttm_bo_driver.h b/trunk/include/drm/ttm/ttm_bo_driver.h
index 6fff43222e20..5af71af6bf88 100644
--- a/trunk/include/drm/ttm/ttm_bo_driver.h
+++ b/trunk/include/drm/ttm/ttm_bo_driver.h
@@ -821,6 +821,36 @@ extern int ttm_bo_reserve(struct ttm_buffer_object *bo,
 			  bool interruptible,
 			  bool no_wait, bool use_sequence, uint32_t sequence);
 
+/**
+ * ttm_bo_reserve_slowpath_nolru:
+ * @bo: A pointer to a struct ttm_buffer_object.
+ * @interruptible: Sleep interruptible if waiting.
+ * @sequence: Set (@bo)->sequence to this value after lock
+ *
+ * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
+ * from all our other reservations. Because there are no other reservations
+ * held by us, this function cannot deadlock any more.
+ *
+ * Will not remove reserved buffers from the lru lists.
+ * Otherwise identical to ttm_bo_reserve_slowpath.
+ */
+extern int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo,
+					 bool interruptible,
+					 uint32_t sequence);
+
+
+/**
+ * ttm_bo_reserve_slowpath:
+ * @bo: A pointer to a struct ttm_buffer_object.
+ * @interruptible: Sleep interruptible if waiting.
+ * @sequence: Set (@bo)->sequence to this value after lock
+ *
+ * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
+ * from all our other reservations. Because there are no other reservations
+ * held by us, this function cannot deadlock any more.
+ */
+extern int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
+				   bool interruptible, uint32_t sequence);
 
 /**
  * ttm_bo_reserve_nolru: