drm/vmwgfx: Don't refcount command-buffer managed resource lookups during command...

The typical pattern of these lookups are
-Lookup
-Put on validate list if not already there.
-Unreference
And since we are the exclusive user of the context during lookup time,
we can be sure that the resource will stay alive during the sequence.
So avoid taking a reference during lookup, and also avoid unreferencing
when done.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c
index 3b75af9bf85f353b3c7c0a6e1041dd119a92f5ce..4ac55fc2bf97021e36a2035dc5b5a830183c996c 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c
@@ -89,8 +89,7 @@ vmw_cmdbuf_res_lookup(struct vmw_cmdbuf_res_manager *man,
        if (unlikely(ret != 0))
                return ERR_PTR(ret);
 
-       return vmw_resource_reference
-               (drm_hash_entry(hash, struct vmw_cmdbuf_res, hash)->res);
+       return drm_hash_entry(hash, struct vmw_cmdbuf_res, hash)->res;
 }
 
 /**

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 15e83b39e26df10a47536f779774218db895fea6..13db7efcb89c8071939e6c52a49d094deafbac99 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -314,10 +314,14 @@ static int vmw_view_res_val_add(struct vmw_sw_context *sw_context,
  *
  * The view is represented by a view id and the DX context it's created on,
  * or scheduled for creation on. If there is no DX context set, the function
- * will return -EINVAL. Otherwise returns 0 on success and -EINVAL on failure.
+ * will return an -EINVAL error pointer.
+ *
+ * Returns: Unreferenced pointer to the resource on success, negative error
+ * pointer on failure.
  */
-static int vmw_view_id_val_add(struct vmw_sw_context *sw_context,
-                              enum vmw_view_type view_type, u32 id)
+static struct vmw_resource *
+vmw_view_id_val_add(struct vmw_sw_context *sw_context,
+                   enum vmw_view_type view_type, u32 id)
 {
        struct vmw_ctx_validation_info *ctx_node = sw_context->dx_ctx_node;
        struct vmw_resource *view;
@@ -325,17 +329,18 @@ static int vmw_view_id_val_add(struct vmw_sw_context *sw_context,
 
        if (!ctx_node) {
                DRM_ERROR("DX Context not set.\n");
-               return -EINVAL;
+               return ERR_PTR(-EINVAL);
        }
 
        view = vmw_view_lookup(sw_context->man, view_type, id);
        if (IS_ERR(view))
-               return PTR_ERR(view);
+               return view;
 
        ret = vmw_view_res_val_add(sw_context, view);
-       vmw_resource_unreference(&view);
+       if (ret)
+               return ERR_PTR(ret);
 
-       return ret;
+       return view;
 }
 
 /**
@@ -740,34 +745,24 @@ static int vmw_view_bindings_add(struct vmw_sw_context *sw_context,
                                 u32 first_slot)
 {
        struct vmw_ctx_validation_info *ctx_node = sw_context->dx_ctx_node;
-       struct vmw_cmdbuf_res_manager *man;
        u32 i;
-       int ret;
 
        if (!ctx_node) {
                DRM_ERROR("DX Context not set.\n");
                return -EINVAL;
        }
 
-       man = sw_context->man;
        for (i = 0; i < num_views; ++i) {
                struct vmw_ctx_bindinfo_view binding;
                struct vmw_resource *view = NULL;
 
                if (view_ids[i] != SVGA3D_INVALID_ID) {
-                       view = vmw_view_lookup(man, view_type, view_ids[i]);
+                       view = vmw_view_id_val_add(sw_context, view_type,
+                                                  view_ids[i]);
                        if (IS_ERR(view)) {
                                DRM_ERROR("View not found.\n");
                                return PTR_ERR(view);
                        }
-
-                       ret = vmw_view_res_val_add(sw_context, view);
-                       if (ret) {
-                               DRM_ERROR("Could not add view to "
-                                         "validation list.\n");
-                               vmw_resource_unreference(&view);
-                               return ret;
-                       }
                }
                binding.bi.ctx = ctx_node->ctx;
                binding.bi.res = view;
@@ -776,8 +771,6 @@ static int vmw_view_bindings_add(struct vmw_sw_context *sw_context,
                binding.slot = first_slot + i;
                vmw_binding_add(ctx_node->staged, &binding.bi,
                                shader_slot, binding.slot);
-               if (view)
-                       vmw_resource_unreference(&view);
        }
 
        return 0;
@@ -2136,11 +2129,8 @@ static int vmw_cmd_set_shader(struct vmw_private *dev_priv,
                                        cmd->body.type);
 
                if (!IS_ERR(res)) {
-                       struct vmw_resource *tmp_res = res;
-
                        ret = vmw_cmd_res_reloc_add(dev_priv, sw_context,
                                                    &cmd->body.shid, res);
-                       vmw_resource_unreference(&tmp_res);
                        if (unlikely(ret != 0))
                                return ret;
                }
@@ -2359,7 +2349,7 @@ static int vmw_cmd_dx_set_shader(struct vmw_private *dev_priv,
 
                ret = vmw_resource_val_add(sw_context, res);
                if (ret)
-                       goto out_unref;
+                       return ret;
        }
 
        binding.bi.ctx = ctx_node->ctx;
@@ -2369,11 +2359,8 @@ static int vmw_cmd_dx_set_shader(struct vmw_private *dev_priv,
 
        vmw_binding_add(ctx_node->staged, &binding.bi,
                        binding.shader_slot, 0);
-out_unref:
-       if (res)
-               vmw_resource_unreference(&res);
 
-       return ret;
+       return 0;
 }
 
 /**
@@ -2530,8 +2517,8 @@ static int vmw_cmd_dx_clear_rendertarget_view(struct vmw_private *dev_priv,
                SVGA3dCmdDXClearRenderTargetView body;
        } *cmd = container_of(header, typeof(*cmd), header);
 
-       return vmw_view_id_val_add(sw_context, vmw_view_rt,
-                                  cmd->body.renderTargetViewId);
+       return PTR_RET(vmw_view_id_val_add(sw_context, vmw_view_rt,
+                                          cmd->body.renderTargetViewId));
 }
 
 /**
@@ -2551,8 +2538,8 @@ static int vmw_cmd_dx_clear_depthstencil_view(struct vmw_private *dev_priv,
                SVGA3dCmdDXClearDepthStencilView body;
        } *cmd = container_of(header, typeof(*cmd), header);
 
-       return vmw_view_id_val_add(sw_context, vmw_view_ds,
-                                  cmd->body.depthStencilViewId);
+       return PTR_RET(vmw_view_id_val_add(sw_context, vmw_view_ds,
+                                          cmd->body.depthStencilViewId));
 }
 
 static int vmw_cmd_dx_view_define(struct vmw_private *dev_priv,
@@ -2904,17 +2891,13 @@ static int vmw_cmd_dx_bind_shader(struct vmw_private *dev_priv,
        ret = vmw_resource_val_add(sw_context, res);
        if (ret) {
                DRM_ERROR("Error creating resource validation node.\n");
-               goto out_unref;
+               return ret;
        }
 
 
-       ret = vmw_cmd_res_switch_backup(dev_priv, sw_context, res,
-                                       &cmd->body.mobid,
-                                       cmd->body.offsetInBytes);
-out_unref:
-       vmw_resource_unreference(&res);
-
-       return ret;
+       return vmw_cmd_res_switch_backup(dev_priv, sw_context, res,
+                                        &cmd->body.mobid,
+                                        cmd->body.offsetInBytes);
 }
 
 /**
@@ -2933,8 +2916,8 @@ static int vmw_cmd_dx_genmips(struct vmw_private *dev_priv,
                SVGA3dCmdDXGenMips body;
        } *cmd = container_of(header, typeof(*cmd), header);
 
-       return vmw_view_id_val_add(sw_context, vmw_view_sr,
-                                  cmd->body.shaderResourceViewId);
+       return PTR_RET(vmw_view_id_val_add(sw_context, vmw_view_sr,
+                                          cmd->body.shaderResourceViewId));
 }
 
 /**