drm/vmwgfx: Fix up and comment the dumb buffer implementation

Allocation was duplicating code. Comments were missing.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>

1 files changed, 37 insertions, 27 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index efe2b74c5eb1..4381e270d032 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -781,54 +781,55 @@ err_ref:
 }
 
 
+/**
+ * vmw_dumb_create - Create a dumb kms buffer
+ *
+ * @file_priv: Pointer to a struct drm_file identifying the caller.
+ * @dev: Pointer to the drm device.
+ * @args: Pointer to a struct drm_mode_create_dumb structure
+ *
+ * This is a driver callback for the core drm create_dumb functionality.
+ * Note that this is very similar to the vmw_dmabuf_alloc ioctl, except
+ * that the arguments have a different format.
+ */
 int vmw_dumb_create(struct drm_file *file_priv,
                     struct drm_device *dev,
                     struct drm_mode_create_dumb *args)
 {
         struct vmw_private *dev_priv = vmw_priv(dev);
         struct vmw_master *vmaster = vmw_master(file_priv->master);
-        struct vmw_user_dma_buffer *vmw_user_bo;
-        struct ttm_buffer_object *tmp;
+        struct vmw_dma_buffer *dma_buf;
         int ret;
 
         args->pitch = args->width * ((args->bpp + 7) / 8);
         args->size = args->pitch * args->height;
 
-        vmw_user_bo = kzalloc(sizeof(*vmw_user_bo), GFP_KERNEL);
-        if (vmw_user_bo == NULL)
-                return -ENOMEM;
-
         ret = ttm_read_lock(&vmaster->lock, true);
-        if (ret != 0) {
-                kfree(vmw_user_bo);
+        if (unlikely(ret != 0))
                 return ret;
-        }
-
-        ret = vmw_dmabuf_init(dev_priv, &vmw_user_bo->dma, args->size,
-                              &vmw_vram_sys_placement, true,
-                              &vmw_user_dmabuf_destroy);
-        if (ret != 0)
-                goto out_no_dmabuf;
 
-        tmp = ttm_bo_reference(&vmw_user_bo->dma.base);
-        ret = ttm_prime_object_init(vmw_fpriv(file_priv)->tfile,
-                                    args->size,
-                                    &vmw_user_bo->prime,
-                                    false,
-                                    ttm_buffer_type,
-                                    &vmw_user_dmabuf_release, NULL);
+        ret = vmw_user_dmabuf_alloc(dev_priv, vmw_fpriv(file_priv)->tfile,
+                                    args->size, false, &args->handle,
+                                    &dma_buf);
         if (unlikely(ret != 0))
-                goto out_no_base_object;
-
-        args->handle = vmw_user_bo->prime.base.hash.key;
+                goto out_no_dmabuf;
 
-out_no_base_object:
-        ttm_bo_unref(&tmp);
+        vmw_dmabuf_unreference(&dma_buf);
 out_no_dmabuf:
         ttm_read_unlock(&vmaster->lock);
         return ret;
 }
 
+/**
+ * vmw_dumb_map_offset - Return the address space offset of a dumb buffer
+ *
+ * @file_priv: Pointer to a struct drm_file identifying the caller.
+ * @dev: Pointer to the drm device.
+ * @handle: Handle identifying the dumb buffer.
+ * @offset: The address space offset returned.
+ *
+ * This is a driver callback for the core drm dumb_map_offset functionality.
+ */
 int vmw_dumb_map_offset(struct drm_file *file_priv,
                         struct drm_device *dev, uint32_t handle,
                         uint64_t *offset)
@@ -846,6 +847,15 @@ int vmw_dumb_map_offset(struct drm_file *file_priv,
         return 0;
 }
 
+/**
+ * vmw_dumb_destroy - Destroy a dumb boffer
+ *
+ * @file_priv: Pointer to a struct drm_file identifying the caller.
+ * @dev: Pointer to the drm device.
+ * @handle: Handle identifying the dumb buffer.
+ *
+ * This is a driver callback for the core drm dumb_destroy functionality.
+ */
 int vmw_dumb_destroy(struct drm_file *file_priv,
                      struct drm_device *dev,
                      uint32_t handle)