drm/vmwgfx: Make sure bo's are unpinned before putting them back

During cotable resize we pin the backup buffer to make sure the
trylock doesn't fail. We were never unpinning the backup buffer
resulting in every subsequent cotable resize trying to release a
pinned bo. After we copy the old backup to the new we can release
the pin.
Mob's are always pinned so we just have to make sure we unpin
them before releasing them.

Reviewed-by: Thomas Hellström (Intel) <thomas_os@shipmail.org>
Fixes: d1a73c641afd ("drm/vmwgfx: Make sure we unpin no longer needed buffers")
Link: https://patchwork.freedesktop.org/patch/msgid/20210413205938.788366-1-zackr@vmware.com
Signed-off-by: Zack Rusin <zackr@vmware.com>

3 files changed, 19 insertions, 8 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_cotable.c b/drivers/gpu/drm/vmwgfx/vmwgfx_cotable.c
index ba658fa9cf6c..183571c387b7 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_cotable.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cotable.c
@@ -481,11 +481,15 @@ static int vmw_cotable_resize(struct vmw_resource *res, size_t new_size)
 	vmw_bo_unreference(&old_buf);
 	res->id = vcotbl->type;
 
+	/* Release the pin acquired in vmw_bo_init */
+	ttm_bo_unpin(bo);
+
 	return 0;
 
 out_map_new:
 	ttm_bo_kunmap(&old_map);
 out_wait:
+	ttm_bo_unpin(bo);
 	ttm_bo_unreserve(bo);
 	vmw_bo_unreference(&buf);
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 8087a9013455..eb76a6b9ebca 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -1522,11 +1522,8 @@ static inline void vmw_bo_unreference(struct vmw_buffer_object **buf)
 	struct vmw_buffer_object *tmp_buf = *buf;
 
 	*buf = NULL;
-	if (tmp_buf != NULL) {
-		if (tmp_buf->base.pin_count > 0)
-			ttm_bo_unpin(&tmp_buf->base);
+	if (tmp_buf != NULL)
 		ttm_bo_put(&tmp_buf->base);
-	}
 }
 
 static inline struct vmw_buffer_object *
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
index a0b53141dded..f2d625415458 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
@@ -94,6 +94,16 @@ static void vmw_mob_pt_setup(struct vmw_mob *mob,
 			     struct vmw_piter data_iter,
 			     unsigned long num_data_pages);
 
+
+static inline void vmw_bo_unpin_unlocked(struct ttm_buffer_object *bo)
+{
+	int ret = ttm_bo_reserve(bo, false, true, NULL);
+	BUG_ON(ret != 0);
+	ttm_bo_unpin(bo);
+	ttm_bo_unreserve(bo);
+}
+
+
 /*
  * vmw_setup_otable_base - Issue an object table base setup command to
  * the device
@@ -277,7 +287,7 @@ out_no_setup:
 						 &batch->otables[i]);
 	}
 
-	ttm_bo_unpin(batch->otable_bo);
+	vmw_bo_unpin_unlocked(batch->otable_bo);
 	ttm_bo_put(batch->otable_bo);
 	batch->otable_bo = NULL;
 	return ret;
@@ -341,9 +351,9 @@ static void vmw_otable_batch_takedown(struct vmw_private *dev_priv,
 	BUG_ON(ret != 0);
 
 	vmw_bo_fence_single(bo, NULL);
+	ttm_bo_unpin(bo);
 	ttm_bo_unreserve(bo);
 
-	ttm_bo_unpin(batch->otable_bo);
 	ttm_bo_put(batch->otable_bo);
 	batch->otable_bo = NULL;
 }
@@ -530,7 +540,7 @@ static void vmw_mob_pt_setup(struct vmw_mob *mob,
 void vmw_mob_destroy(struct vmw_mob *mob)
 {
 	if (mob->pt_bo) {
-		ttm_bo_unpin(mob->pt_bo);
+		vmw_bo_unpin_unlocked(mob->pt_bo);
 		ttm_bo_put(mob->pt_bo);
 		mob->pt_bo = NULL;
 	}
@@ -646,7 +656,7 @@ int vmw_mob_bind(struct vmw_private *dev_priv,
 out_no_cmd_space:
 	vmw_fifo_resource_dec(dev_priv);
 	if (pt_set_up) {
-		ttm_bo_unpin(mob->pt_bo);
+		vmw_bo_unpin_unlocked(mob->pt_bo);
 		ttm_bo_put(mob->pt_bo);
 		mob->pt_bo = NULL;
 	}