drm/vmwgfx: Make user resource lookups reference-free during validation
authorThomas Hellstrom <thellstrom@vmware.com>
Wed, 26 Sep 2018 14:32:40 +0000 (16:32 +0200)
committerThomas Hellstrom <thellstrom@vmware.com>
Fri, 28 Sep 2018 06:57:09 +0000 (08:57 +0200)
Make the process of looking up a user resource and adding it to the
validation list reference-free unless when it's actually added to the
validation list where a single reference is taken.
This saves two locked atomic operations per command stream buffer object
handle lookup, unless there is a lookup cache hit.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
drivers/gpu/drm/vmwgfx/vmwgfx_resource.c

index 061fa937f369cf1eb9b3736d09a4577aee9cca5c..59f614225bcd72b8a84a5de42813359e9a2760d0 100644 (file)
@@ -337,8 +337,6 @@ struct vmw_ctx_validation_info;
  * @last_query_ctx: Last context that submitted a query
  * @needs_post_query_barrier: Whether a query barrier is needed after
  * command submission
- * @error_resource: Pointer to hold a reference to the resource causing
- * an error
  * @staged_bindings: Cached per-context binding tracker
  * @staged_bindings_inuse: Whether the cached per-context binding tracker
  * is in use
@@ -365,7 +363,6 @@ struct vmw_sw_context{
        struct vmw_res_cache_entry res_cache[vmw_res_max];
        struct vmw_resource *last_query_ctx;
        bool needs_post_query_barrier;
-       struct vmw_resource *error_resource;
        struct vmw_ctx_binding_state *staged_bindings;
        bool staged_bindings_inuse;
        struct list_head staged_cmd_res;
@@ -698,6 +695,12 @@ extern int vmw_user_resource_lookup_handle(
        uint32_t handle,
        const struct vmw_user_resource_conv *converter,
        struct vmw_resource **p_res);
+extern struct vmw_resource *
+vmw_user_resource_noref_lookup_handle(struct vmw_private *dev_priv,
+                                     struct ttm_object_file *tfile,
+                                     uint32_t handle,
+                                     const struct vmw_user_resource_conv *
+                                     converter);
 extern int vmw_stream_claim_ioctl(struct drm_device *dev, void *data,
                                  struct drm_file *file_priv);
 extern int vmw_stream_unref_ioctl(struct drm_device *dev, void *data,
@@ -716,6 +719,15 @@ extern int vmw_query_readback_all(struct vmw_buffer_object *dx_query_mob);
 extern void vmw_resource_evict_all(struct vmw_private *dev_priv);
 extern void vmw_resource_unbind_list(struct vmw_buffer_object *vbo);
 
+/**
+ * vmw_user_resource_noref_release - release a user resource pointer looked up
+ * without reference
+ */
+static inline void vmw_user_resource_noref_release(void)
+{
+       ttm_base_object_noref_release();
+}
+
 /**
  * Buffer object helper functions - vmwgfx_bo.c
  */
index dfa2d19274d501fec8e9284062260e90da31a95e..5a6b70ba137aa321fe606946640464d861338087 100644 (file)
@@ -230,16 +230,55 @@ out_err:
 }
 
 /**
- * vmw_resource_val_add - Add a resource to the software context's
- * resource list if it's not already on it.
+ * vmw_execbuf_res_size - calculate extra size fore the resource validation
+ * node
+ * @dev_priv: Pointer to the device private struct.
+ * @res_type: The resource type.
  *
- * @sw_context: Pointer to the software context.
+ * Guest-backed contexts and DX contexts require extra size to store
+ * execbuf private information in the validation node. Typically the
+ * binding manager associated data structures.
+ *
+ * Returns: The extra size requirement based on resource type.
+ */
+static unsigned int vmw_execbuf_res_size(struct vmw_private *dev_priv,
+                                        enum vmw_res_type res_type)
+{
+       return (res_type == vmw_res_dx_context ||
+               (res_type == vmw_res_context && dev_priv->has_mob)) ?
+               sizeof(struct vmw_ctx_validation_info) : 0;
+}
+
+/**
+ * vmw_execbuf_rcache_update - Update a resource-node cache entry
+ *
+ * @rcache: Pointer to the entry to update.
  * @res: Pointer to the resource.
- * @p_node On successful return points to a valid pointer to a
- * struct vmw_resource_val_node, if non-NULL on entry.
+ * @private: Pointer to the execbuf-private space in the resource
+ * validation node.
  */
-static int vmw_resource_val_add(struct vmw_sw_context *sw_context,
-                               struct vmw_resource *res)
+static void vmw_execbuf_rcache_update(struct vmw_res_cache_entry *rcache,
+                                     struct vmw_resource *res,
+                                     void *private)
+{
+       rcache->res = res;
+       rcache->private = private;
+       rcache->valid = 1;
+       rcache->valid_handle = 0;
+}
+
+/**
+ * vmw_execbuf_res_noref_val_add - Add a resource described by an
+ * unreferenced rcu-protected pointer to the validation list.
+ * @sw_context: Pointer to the software context.
+ * @res: Unreferenced rcu-protected pointer to the resource.
+ *
+ * Returns: 0 on success. Negative error code on failure. Typical error
+ * codes are %-EINVAL on inconsistency and %-ESRCH if the resource was
+ * doomed.
+ */
+static int vmw_execbuf_res_noref_val_add(struct vmw_sw_context *sw_context,
+                                        struct vmw_resource *res)
 {
        struct vmw_private *dev_priv = res->dev_priv;
        int ret;
@@ -247,18 +286,18 @@ static int vmw_resource_val_add(struct vmw_sw_context *sw_context,
        struct vmw_res_cache_entry *rcache;
        struct vmw_ctx_validation_info *ctx_info;
        bool first_usage;
-       size_t priv_size;
+       unsigned int priv_size;
 
-       /*
-        * If the resource is a context, set up structures to track
-        * context bindings.
-        */
-       priv_size = (res_type == vmw_res_dx_context ||
-                    (res_type == vmw_res_context && dev_priv->has_mob)) ?
-               sizeof(*ctx_info) : 0;
+       rcache = &sw_context->res_cache[res_type];
+       if (likely(rcache->valid && rcache->res == res)) {
+               vmw_user_resource_noref_release();
+               return 0;
+       }
 
+       priv_size = vmw_execbuf_res_size(dev_priv, res_type);
        ret = vmw_validation_add_resource(sw_context->ctx, res, priv_size,
                                          (void **)&ctx_info, &first_usage);
+       vmw_user_resource_noref_release();
        if (ret)
                return ret;
 
@@ -269,14 +308,37 @@ static int vmw_resource_val_add(struct vmw_sw_context *sw_context,
                        return ret;
        }
 
-       /* Cache info about the last added resource */
+       vmw_execbuf_rcache_update(rcache, res, ctx_info);
+       return 0;
+}
+
+/**
+ * vmw_execbuf_res_noctx_val_add - Add a non-context resource to the resource
+ * validation list if it's not already on it
+ * @sw_context: Pointer to the software context.
+ * @res: Pointer to the resource.
+ *
+ * Returns: Zero on success. Negative error code on failure.
+ */
+static int vmw_execbuf_res_noctx_val_add(struct vmw_sw_context *sw_context,
+                                        struct vmw_resource *res)
+{
+       struct vmw_res_cache_entry *rcache;
+       enum vmw_res_type res_type = vmw_res_type(res);
+       void *ptr;
+       int ret;
+
        rcache = &sw_context->res_cache[res_type];
-       rcache->res = res;
-       rcache->private = ctx_info;
-       rcache->valid = 1;
-       rcache->valid_handle = 0;
+       if (likely(rcache->valid && rcache->res == res))
+               return 0;
 
-       return ret;
+       ret = vmw_validation_add_resource(sw_context->ctx, res, 0, &ptr, NULL);
+       if (ret)
+               return ret;
+
+       vmw_execbuf_rcache_update(rcache, res, ptr);
+
+       return 0;
 }
 
 /**
@@ -297,11 +359,11 @@ static int vmw_view_res_val_add(struct vmw_sw_context *sw_context,
         * First add the resource the view is pointing to, otherwise
         * it may be swapped out when the view is validated.
         */
-       ret = vmw_resource_val_add(sw_context, vmw_view_srf(view));
+       ret = vmw_execbuf_res_noctx_val_add(sw_context, vmw_view_srf(view));
        if (ret)
                return ret;
 
-       return vmw_resource_val_add(sw_context, view);
+       return vmw_execbuf_res_noctx_val_add(sw_context, view);
 }
 
 /**
@@ -371,7 +433,7 @@ static int vmw_resource_context_res_add(struct vmw_private *dev_priv,
                        if (IS_ERR(res))
                                continue;
 
-                       ret = vmw_resource_val_add(sw_context, res);
+                       ret = vmw_execbuf_res_noctx_val_add(sw_context, res);
                        if (unlikely(ret != 0))
                                return ret;
                }
@@ -383,16 +445,11 @@ static int vmw_resource_context_res_add(struct vmw_private *dev_priv,
        binding_list = vmw_context_binding_list(ctx);
 
        list_for_each_entry(entry, binding_list, ctx_list) {
-               /* entry->res is not refcounted */
-               res = vmw_resource_reference_unless_doomed(entry->res);
-               if (unlikely(res == NULL))
-                       continue;
-
                if (vmw_res_type(entry->res) == vmw_res_view)
                        ret = vmw_view_res_val_add(sw_context, entry->res);
                else
-                       ret = vmw_resource_val_add(sw_context, entry->res);
-               vmw_resource_unreference(&res);
+                       ret = vmw_execbuf_res_noctx_val_add(sw_context,
+                                                           entry->res);
                if (unlikely(ret != 0))
                        break;
        }
@@ -534,38 +591,6 @@ static int vmw_resources_reserve(struct vmw_sw_context *sw_context)
        return ret;
 }
 
-/**
- * vmw_cmd_res_reloc_add - Add a resource to a software context's
- * relocation- and validation lists.
- * @dev_priv: Pointer to a struct vmw_private identifying the device.
- * @sw_context: Pointer to the software context.
- * @id_loc: Pointer to where the id that needs translation is located.
- * @res: Valid pointer to a struct vmw_resource.
- *
- *  Return: Zero on success, negative error code on error
- */
-static int vmw_cmd_res_reloc_add(struct vmw_private *dev_priv,
-                                struct vmw_sw_context *sw_context,
-                                uint32_t *id_loc,
-                                struct vmw_resource *res)
-{
-       int ret;
-
-       ret = vmw_resource_relocation_add(sw_context, res,
-                                         vmw_ptr_diff(sw_context->buf_start,
-                                                      id_loc),
-                                         vmw_res_rel_normal);
-       if (unlikely(ret != 0))
-               return ret;
-
-       ret = vmw_resource_val_add(sw_context, res);
-       if (unlikely(ret != 0))
-               return ret;
-
-       return 0;
-}
-
-
 /**
  * vmw_cmd_res_check - Check that a resource is present and if so, put it
  * on the resource validate list unless it's already there.
@@ -587,8 +612,7 @@ vmw_cmd_res_check(struct vmw_private *dev_priv,
                  uint32_t *id_loc,
                  struct vmw_resource **p_res)
 {
-       struct vmw_res_cache_entry *rcache =
-               &sw_context->res_cache[res_type];
+       struct vmw_res_cache_entry *rcache = &sw_context->res_cache[res_type];
        struct vmw_resource *res;
        int ret;
 
@@ -603,56 +627,41 @@ vmw_cmd_res_check(struct vmw_private *dev_priv,
                return 0;
        }
 
-       /*
-        * Fastpath in case of repeated commands referencing the same
-        * resource
-        */
-
        if (likely(rcache->valid_handle && *id_loc == rcache->handle)) {
-               struct vmw_resource *res = rcache->res;
+               res = rcache->res;
+       } else {
+               unsigned int size = vmw_execbuf_res_size(dev_priv, res_type);
 
-               if (p_res)
-                       *p_res = res;
+               ret = vmw_validation_preload_res(sw_context->ctx, size);
+               if (ret)
+                       return ret;
 
-               return vmw_resource_relocation_add
-                       (sw_context, res,
-                        vmw_ptr_diff(sw_context->buf_start, id_loc),
-                        vmw_res_rel_normal);
-       }
+               res = vmw_user_resource_noref_lookup_handle
+                       (dev_priv, sw_context->fp->tfile, *id_loc, converter);
+               if (unlikely(IS_ERR(res))) {
+                       DRM_ERROR("Could not find or use resource 0x%08x.\n",
+                                 (unsigned int) *id_loc);
+                       return PTR_ERR(res);
+               }
 
-       ret = vmw_user_resource_lookup_handle(dev_priv,
-                                             sw_context->fp->tfile,
-                                             *id_loc,
-                                             converter,
-                                             &res);
-       if (unlikely(ret != 0)) {
-               DRM_ERROR("Could not find or use resource 0x%08x.\n",
-                         (unsigned) *id_loc);
-               dump_stack();
-               return ret;
-       }
+               ret = vmw_execbuf_res_noref_val_add(sw_context, res);
+               if (unlikely(ret != 0))
+                       return ret;
 
-       ret = vmw_cmd_res_reloc_add(dev_priv, sw_context, id_loc,
-                                   res);
-       if (unlikely(ret != 0))
-               goto out_no_reloc;
+               if (rcache->valid && rcache->res == res) {
+                       rcache->valid_handle = true;
+                       rcache->handle = *id_loc;
+               }
+       }
 
+       ret = vmw_resource_relocation_add(sw_context, res,
+                                         vmw_ptr_diff(sw_context->buf_start,
+                                                      id_loc),
+                                         vmw_res_rel_normal);
        if (p_res)
                *p_res = res;
 
-       if (rcache->valid && rcache->res == res) {
-               rcache->valid_handle = true;
-               rcache->handle = *id_loc;
-       }
-
-       vmw_resource_unreference(&res);
        return 0;
-
-out_no_reloc:
-       BUG_ON(sw_context->error_resource != NULL);
-       sw_context->error_resource = res;
-
-       return ret;
 }
 
 /**
@@ -854,9 +863,9 @@ static int vmw_cmd_set_render_target_check(struct vmw_private *dev_priv,
                return ret;
 
        ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
-                               user_surface_converter,
-                               &cmd->body.target.sid, &res);
-       if (unlikely(ret != 0))
+                               user_surface_converter, &cmd->body.target.sid,
+                               &res);
+       if (unlikely(ret))
                return ret;
 
        if (dev_priv->has_mob) {
@@ -890,8 +899,8 @@ static int vmw_cmd_surface_copy_check(struct vmw_private *dev_priv,
        cmd = container_of(header, struct vmw_sid_cmd, header);
 
        ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface,
-                               user_surface_converter,
-                               &cmd->body.src.sid, NULL);
+                                         user_surface_converter,
+                                         &cmd->body.src.sid, NULL);
        if (ret)
                return ret;
 
@@ -2127,8 +2136,7 @@ static int vmw_cmd_set_shader(struct vmw_private *dev_priv,
                                        cmd->body.type);
 
                if (!IS_ERR(res)) {
-                       ret = vmw_cmd_res_reloc_add(dev_priv, sw_context,
-                                                   &cmd->body.shid, res);
+                       ret = vmw_execbuf_res_noctx_val_add(sw_context, res);
                        if (unlikely(ret != 0))
                                return ret;
                }
@@ -2345,7 +2353,7 @@ static int vmw_cmd_dx_set_shader(struct vmw_private *dev_priv,
                        return PTR_ERR(res);
                }
 
-               ret = vmw_resource_val_add(sw_context, res);
+               ret = vmw_execbuf_res_noctx_val_add(sw_context, res);
                if (ret)
                        return ret;
        }
@@ -2883,13 +2891,12 @@ static int vmw_cmd_dx_bind_shader(struct vmw_private *dev_priv,
                return PTR_ERR(res);
        }
 
-       ret = vmw_resource_val_add(sw_context, res);
+       ret = vmw_execbuf_res_noctx_val_add(sw_context, res);
        if (ret) {
                DRM_ERROR("Error creating resource validation node.\n");
                return ret;
        }
 
-
        return vmw_cmd_res_switch_backup(dev_priv, sw_context, res,
                                         &cmd->body.mobid,
                                         cmd->body.offsetInBytes);
@@ -3781,28 +3788,33 @@ static int vmw_execbuf_tie_context(struct vmw_private *dev_priv,
 {
        struct vmw_resource *res;
        int ret;
+       unsigned int size;
 
        if (handle == SVGA3D_INVALID_ID)
                return 0;
 
-       ret = vmw_user_resource_lookup_handle(dev_priv, sw_context->fp->tfile,
-                                             handle, user_context_converter,
-                                             &res);
-       if (unlikely(ret != 0)) {
+       size = vmw_execbuf_res_size(dev_priv, vmw_res_dx_context);
+       ret = vmw_validation_preload_res(sw_context->ctx, size);
+       if (ret)
+               return ret;
+
+       res = vmw_user_resource_noref_lookup_handle
+               (dev_priv, sw_context->fp->tfile, handle,
+                user_context_converter);
+       if (unlikely(IS_ERR(res))) {
                DRM_ERROR("Could not find or user DX context 0x%08x.\n",
                          (unsigned) handle);
-               return ret;
+               return PTR_ERR(res);
        }
 
-       ret = vmw_resource_val_add(sw_context, res);
+       ret = vmw_execbuf_res_noref_val_add(sw_context, res);
        if (unlikely(ret != 0))
-               goto out_err;
+               return ret;
 
        sw_context->dx_ctx_node = vmw_execbuf_info_from_res(sw_context, res);
        sw_context->man = vmw_context_res_man(res);
-out_err:
-       vmw_resource_unreference(&res);
-       return ret;
+
+       return 0;
 }
 
 int vmw_execbuf_process(struct drm_file *file_priv,
@@ -3818,7 +3830,6 @@ int vmw_execbuf_process(struct drm_file *file_priv,
 {
        struct vmw_sw_context *sw_context = &dev_priv->ctx;
        struct vmw_fence_obj *fence = NULL;
-       struct vmw_resource *error_resource;
        struct vmw_cmdbuf_header *header;
        uint32_t handle;
        int ret;
@@ -4028,8 +4039,6 @@ out_err_nores:
                     !dev_priv->query_cid_valid))
                __vmw_execbuf_release_pinned_bo(dev_priv, NULL);
 out_unlock:
-       error_resource = sw_context->error_resource;
-       sw_context->error_resource = NULL;
        vmw_cmdbuf_res_revert(&sw_context->staged_cmd_res);
        vmw_validation_drop_ht(&val_ctx);
        WARN_ON(!list_empty(&sw_context->ctx_list));
@@ -4040,8 +4049,6 @@ out_unlock:
         * avoid deadlocks in resource destruction paths.
         */
        vmw_validation_unref_lists(&val_ctx);
-       if (unlikely(error_resource != NULL))
-               vmw_resource_unreference(&error_resource);
 out_free_header:
        if (header)
                vmw_cmdbuf_header_free(header);
index cf48d0b157f620d1eefd34c7277e2daf9c0fc513..8a029bade32a8561e0cf12e86d1e6eb28a69b002 100644 (file)
@@ -230,6 +230,41 @@ out_bad_resource:
        return ret;
 }
 
+/**
+ * vmw_user_resource_lookup_handle - lookup a struct resource from a
+ * TTM user-space handle and perform basic type checks
+ *
+ * @dev_priv:     Pointer to a device private struct
+ * @tfile:        Pointer to a struct ttm_object_file identifying the caller
+ * @handle:       The TTM user-space handle
+ * @converter:    Pointer to an object describing the resource type
+ * @p_res:        On successful return the location pointed to will contain
+ *                a pointer to a refcounted struct vmw_resource.
+ *
+ * If the handle can't be found or is associated with an incorrect resource
+ * type, -EINVAL will be returned.
+ */
+struct vmw_resource *
+vmw_user_resource_noref_lookup_handle(struct vmw_private *dev_priv,
+                                     struct ttm_object_file *tfile,
+                                     uint32_t handle,
+                                     const struct vmw_user_resource_conv
+                                     *converter)
+{
+       struct ttm_base_object *base;
+
+       base = ttm_base_object_noref_lookup(tfile, handle);
+       if (!base)
+               return ERR_PTR(-ESRCH);
+
+       if (unlikely(ttm_base_object_type(base) != converter->object_type)) {
+               ttm_base_object_noref_release();
+               return ERR_PTR(-EINVAL);
+       }
+
+       return converter->base_obj_to_res(base);
+}
+
 /**
  * Helper function that looks either a surface or bo.
  *