drm/vmwgfx: Remove the resource avail field

This field was previously used to prevent a lookup of a resource before its
constructor had run to its end. This was mainly intended for an interface
that is now removed that allowed looking up a resource by its device id.

Currently all affected resources are added to the lookup mechanism (its
TTM prime object is initialized) late in the constructor where it's OK to
look up the resource.

This means we can change the device resource_lock to an ordinary spinlock
instead of an rwlock and remove a locking sequence during lookup.

Signed-off-by: Thomas Hellstrom <[e-mail]>
Reviewed-by: Sinclair Yeh <[e-mail]>
Reviewed-by: Deepak Rawat <[e-mail]>

drivers/gpu/drm/vmwgfx/vmwgfx_context.c

···
 		}
 	}
 
-
-
-	vmw_resource_activate(res, vmw_hw_context_destroy);
+	res->hw_destroy = vmw_hw_context_destroy;
 	return 0;
 
 out_cotables:
···
 
 	vmw_fifo_commit(dev_priv, sizeof(*cmd));
 	vmw_fifo_resource_inc(dev_priv);
-	vmw_resource_activate(res, vmw_hw_context_destroy);
+	res->hw_destroy = vmw_hw_context_destroy;
 	return 0;
 
 out_early:

drivers/gpu/drm/vmwgfx/vmwgfx_cotable.c

···
 	vcotbl->type = type;
 	vcotbl->ctx = ctx;
 
-	vmw_resource_activate(&vcotbl->res, vmw_hw_cotable_destroy);
+	vcotbl->res.hw_destroy = vmw_hw_cotable_destroy;
 
 	return &vcotbl->res;
 

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

···
 	mutex_init(&dev_priv->binding_mutex);
 	mutex_init(&dev_priv->requested_layout_mutex);
 	mutex_init(&dev_priv->global_kms_state_mutex);
-	rwlock_init(&dev_priv->resource_lock);
 	ttm_lock_init(&dev_priv->reservation_sem);
+	spin_lock_init(&dev_priv->resource_lock);
 	spin_lock_init(&dev_priv->hw_lock);
 	spin_lock_init(&dev_priv->waiter_lock);
 	spin_lock_init(&dev_priv->cap_lock);

drivers/gpu/drm/vmwgfx/vmwgfx_drv.h

···
 };
 
 struct vmw_res_func;
+
+
+/**
+ * struct vmw-resource - base class for hardware resources
+ *
+ * @kref: For refcounting.
+ * @dev_priv: Pointer to the device private for this resource. Immutable.
+ * @id: Device id. Protected by @dev_priv::resource_lock.
+ * @backup_size: Backup buffer size. Immutable.
+ * @res_dirty: Resource contains data not yet in the backup buffer. Protected
+ * by resource reserved.
+ * @backup_dirty: Backup buffer contains data not yet in the HW resource.
+ * Protecte by resource reserved.
+ * @backup: The backup buffer if any. Protected by resource reserved.
+ * @backup_offset: Offset into the backup buffer if any. Protected by resource
+ * reserved. Note that only a few resource types can have a @backup_offset
+ * different from zero.
+ * @pin_count: The pin count for this resource. A pinned resource has a
+ * pin-count greater than zero. It is not on the resource LRU lists and its
+ * backup buffer is pinned. Hence it can't be evicted.
+ * @func: Method vtable for this resource. Immutable.
+ * @lru_head: List head for the LRU list. Protected by @dev_priv::resource_lock.
+ * @mob_head: List head for the MOB backup list. Protected by @backup reserved.
+ * @binding_head: List head for the context binding list. Protected by
+ * the @dev_priv::binding_mutex
+ * @res_free: The resource destructor.
+ * @hw_destroy: Callback to destroy the resource on the device, as part of
+ * resource destruction.
+ */
 struct vmw_resource {
 	struct kref kref;
 	struct vmw_private *dev_priv;
 	int id;
-	bool avail;
 	unsigned long backup_size;
-	bool res_dirty; /* Protected by backup buffer reserved */
-	bool backup_dirty; /* Protected by backup buffer reserved */
+	bool res_dirty;
+	bool backup_dirty;
 	struct vmw_buffer_object *backup;
 	unsigned long backup_offset;
-	unsigned long pin_count; /* Protected by resource reserved */
+	unsigned long pin_count;
 	const struct vmw_res_func *func;
-	struct list_head lru_head; /* Protected by the resource lock */
-	struct list_head mob_head; /* Protected by @backup reserved */
-	struct list_head binding_head; /* Protected by binding_mutex */
+	struct list_head lru_head;
+	struct list_head mob_head;
+	struct list_head binding_head;
 	void (*res_free) (struct vmw_resource *res);
 	void (*hw_destroy) (struct vmw_resource *res);
 };
···
 	 * Context and surface management.
 	 */
 
-	rwlock_t resource_lock;
+	spinlock_t resource_lock;
 	struct idr res_idr[vmw_res_max];
 	/*
 	 * Block lastclose from racing with firstopen.

drivers/gpu/drm/vmwgfx/vmwgfx_resource.c

···
 	struct vmw_private *dev_priv = res->dev_priv;
 	struct idr *idr = &dev_priv->res_idr[res->func->res_type];
 
-	write_lock(&dev_priv->resource_lock);
+	spin_lock(&dev_priv->resource_lock);
 	if (res->id != -1)
 		idr_remove(idr, res->id);
 	res->id = -1;
-	write_unlock(&dev_priv->resource_lock);
+	spin_unlock(&dev_priv->resource_lock);
 }
 
 static void vmw_resource_release(struct kref *kref)
···
 	int id;
 	struct idr *idr = &dev_priv->res_idr[res->func->res_type];
 
-	write_lock(&dev_priv->resource_lock);
-	res->avail = false;
+	spin_lock(&dev_priv->resource_lock);
 	list_del_init(&res->lru_head);
-	write_unlock(&dev_priv->resource_lock);
+	spin_unlock(&dev_priv->resource_lock);
 	if (res->backup) {
 		struct ttm_buffer_object *bo = &res->backup->base;
 
···
 	else
 		kfree(res);
 
-	write_lock(&dev_priv->resource_lock);
+	spin_lock(&dev_priv->resource_lock);
 	if (id != -1)
 		idr_remove(idr, id);
-	write_unlock(&dev_priv->resource_lock);
+	spin_unlock(&dev_priv->resource_lock);
 }
 
 void vmw_resource_unreference(struct vmw_resource **p_res)
···
 	BUG_ON(res->id != -1);
 
 	idr_preload(GFP_KERNEL);
-	write_lock(&dev_priv->resource_lock);
+	spin_lock(&dev_priv->resource_lock);
 
 	ret = idr_alloc(idr, res, 1, 0, GFP_NOWAIT);
 	if (ret >= 0)
 		res->id = ret;
 
-	write_unlock(&dev_priv->resource_lock);
+	spin_unlock(&dev_priv->resource_lock);
 	idr_preload_end();
 	return ret < 0 ? ret : 0;
 }
···
 	kref_init(&res->kref);
 	res->hw_destroy = NULL;
 	res->res_free = res_free;
-	res->avail = false;
 	res->dev_priv = dev_priv;
 	res->func = func;
 	INIT_LIST_HEAD(&res->lru_head);
···
 		return vmw_resource_alloc_id(res);
 }
 
-/**
- * vmw_resource_activate
- *
- * @res:        Pointer to the newly created resource
- * @hw_destroy: Destroy function. NULL if none.
- *
- * Activate a resource after the hardware has been made aware of it.
- * Set tye destroy function to @destroy. Typically this frees the
- * resource and destroys the hardware resources associated with it.
- * Activate basically means that the function vmw_resource_lookup will
- * find it.
- */
-void vmw_resource_activate(struct vmw_resource *res,
-			   void (*hw_destroy) (struct vmw_resource *))
-{
-	struct vmw_private *dev_priv = res->dev_priv;
-
-	write_lock(&dev_priv->resource_lock);
-	res->avail = true;
-	res->hw_destroy = hw_destroy;
-	write_unlock(&dev_priv->resource_lock);
-}
 
 /**
  * vmw_user_resource_lookup_handle - lookup a struct resource from a
···
 		goto out_bad_resource;
 
 	res = converter->base_obj_to_res(base);
-
-	read_lock(&dev_priv->resource_lock);
-	if (!res->avail || res->res_free != converter->res_free) {
-		read_unlock(&dev_priv->resource_lock);
+	if (res->res_free != converter->res_free)
 		goto out_bad_resource;
-	}
 
 	kref_get(&res->kref);
-	read_unlock(&dev_priv->resource_lock);
 
 	*p_res = res;
 	ret = 0;
···
 	if (!res->func->may_evict || res->id == -1 || res->pin_count)
 		return;
 
-	write_lock(&dev_priv->resource_lock);
+	spin_lock(&dev_priv->resource_lock);
 	list_add_tail(&res->lru_head,
 		      &res->dev_priv->res_lru[res->func->res_type]);
-	write_unlock(&dev_priv->resource_lock);
+	spin_unlock(&dev_priv->resource_lock);
 }
 
 /**
···
 	struct vmw_private *dev_priv = res->dev_priv;
 	int ret;
 
-	write_lock(&dev_priv->resource_lock);
+	spin_lock(&dev_priv->resource_lock);
 	list_del_init(&res->lru_head);
-	write_unlock(&dev_priv->resource_lock);
+	spin_unlock(&dev_priv->resource_lock);
 
 	if (res->func->needs_backup && res->backup == NULL &&
 	    !no_backup) {
···
 		if (likely(ret != -EBUSY))
 			break;
 
-		write_lock(&dev_priv->resource_lock);
+		spin_lock(&dev_priv->resource_lock);
 		if (list_empty(lru_list) || !res->func->may_evict) {
 			DRM_ERROR("Out of device device resources "
 				  "for %s.\n", res->func->type_name);
 			ret = -EBUSY;
-			write_unlock(&dev_priv->resource_lock);
+			spin_unlock(&dev_priv->resource_lock);
 			break;
 		}
 
···
 					  lru_head));
 		list_del_init(&evict_res->lru_head);
 
-		write_unlock(&dev_priv->resource_lock);
+		spin_unlock(&dev_priv->resource_lock);
 
 		/* Trylock backup buffers with a NULL ticket. */
 		ret = vmw_resource_do_evict(NULL, evict_res, intr);
 		if (unlikely(ret != 0)) {
-			write_lock(&dev_priv->resource_lock);
+			spin_lock(&dev_priv->resource_lock);
 			list_add_tail(&evict_res->lru_head, lru_list);
-			write_unlock(&dev_priv->resource_lock);
+			spin_unlock(&dev_priv->resource_lock);
 			if (ret == -ERESTARTSYS ||
 			    ++err_count > VMW_RES_EVICT_ERR_COUNT) {
 				vmw_resource_unreference(&evict_res);
···
 	struct ww_acquire_ctx ticket;
 
 	do {
-		write_lock(&dev_priv->resource_lock);
+		spin_lock(&dev_priv->resource_lock);
 
 		if (list_empty(lru_list))
 			goto out_unlock;
···
 			list_first_entry(lru_list, struct vmw_resource,
 					 lru_head));
 		list_del_init(&evict_res->lru_head);
-		write_unlock(&dev_priv->resource_lock);
+		spin_unlock(&dev_priv->resource_lock);
 
 		/* Wait lock backup buffers with a ticket. */
 		ret = vmw_resource_do_evict(&ticket, evict_res, false);
 		if (unlikely(ret != 0)) {
-			write_lock(&dev_priv->resource_lock);
+			spin_lock(&dev_priv->resource_lock);
 			list_add_tail(&evict_res->lru_head, lru_list);
-			write_unlock(&dev_priv->resource_lock);
+			spin_unlock(&dev_priv->resource_lock);
 			if (++err_count > VMW_RES_EVICT_ERR_COUNT) {
 				vmw_resource_unreference(&evict_res);
 				return;
···
 	} while (1);
 
 out_unlock:
-	write_unlock(&dev_priv->resource_lock);
+	spin_unlock(&dev_priv->resource_lock);
 }
 
 /**

drivers/gpu/drm/vmwgfx/vmwgfx_resource_priv.h

···
 		      bool delay_id,
 		      void (*res_free) (struct vmw_resource *res),
 		      const struct vmw_res_func *func);
-void vmw_resource_activate(struct vmw_resource *res,
-			   void (*hw_destroy) (struct vmw_resource *));
 int
 vmw_simple_resource_create_ioctl(struct drm_device *dev,
 				 void *data,

drivers/gpu/drm/vmwgfx/vmwgfx_shader.c

···
 	shader->num_input_sig = num_input_sig;
 	shader->num_output_sig = num_output_sig;
 
-	vmw_resource_activate(res, vmw_hw_shader_destroy);
+	res->hw_destroy = vmw_hw_shader_destroy;
 	return 0;
 }
 
···
 		goto out_resource_init;
 
 	res->id = shader->id;
-	vmw_resource_activate(res, vmw_hw_shader_destroy);
+	res->hw_destroy = vmw_hw_shader_destroy;
 
 out_resource_init:
 	vmw_resource_unreference(&res);

drivers/gpu/drm/vmwgfx/vmwgfx_simple_resource.c

···
 		return ret;
 	}
 
-	vmw_resource_activate(&simple->res, simple->func->hw_destroy);
+	simple->res.hw_destroy = simple->func->hw_destroy;
 
 	return 0;
 }

drivers/gpu/drm/vmwgfx/vmwgfx_so.c

···
 		goto out_resource_init;
 
 	res->id = view->view_id;
-	vmw_resource_activate(res, vmw_hw_view_destroy);
+	res->hw_destroy = vmw_hw_view_destroy;
 
 out_resource_init:
 	vmw_resource_unreference(&res);

drivers/gpu/drm/vmwgfx/vmwgfx_surface.c

···
 	 */
 
 	INIT_LIST_HEAD(&srf->view_list);
-	vmw_resource_activate(res, vmw_hw_surface_destroy);
+	res->hw_destroy = vmw_hw_surface_destroy;
 	return ret;
 }