drm/vmwgfx: Emulate legacy shaders on guest-backed devices v2

Command stream legacy shader creation and destruction is replaced by
NOPs in the command stream, and instead guest-backed shaders are created
and destroyed as part of the command validation process.

v2: Removed some stray debug messages.

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

1 files changed, 417 insertions, 48 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c
index 1457ec4b7125..be85d7fdfb5b 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c
@@ -29,6 +29,8 @@
 #include "vmwgfx_resource_priv.h"
 #include "ttm/ttm_placement.h"
 
+#define VMW_COMPAT_SHADER_HT_ORDER 12
+
 struct vmw_shader {
 	struct vmw_resource res;
 	SVGA3dShaderType type;
@@ -40,6 +42,50 @@ struct vmw_user_shader {
 	struct vmw_shader shader;
 };
 
+/**
+ * enum vmw_compat_shader_state - Staging state for compat shaders
+ */
+enum vmw_compat_shader_state {
+	VMW_COMPAT_COMMITED,
+	VMW_COMPAT_ADD,
+	VMW_COMPAT_DEL
+};
+
+/**
+ * struct vmw_compat_shader - Metadata for compat shaders.
+ *
+ * @handle: The TTM handle of the guest backed shader.
+ * @tfile: The struct ttm_object_file the guest backed shader is registered
+ * with.
+ * @hash: Hash item for lookup.
+ * @head: List head for staging lists or the compat shader manager list.
+ * @state: Staging state.
+ *
+ * The structure is protected by the cmdbuf lock.
+ */
+struct vmw_compat_shader {
+	u32 handle;
+	struct ttm_object_file *tfile;
+	struct drm_hash_item hash;
+	struct list_head head;
+	enum vmw_compat_shader_state state;
+};
+
+/**
+ * struct vmw_compat_shader_manager - Compat shader manager.
+ *
+ * @shaders: Hash table containing staged and commited compat shaders
+ * @list: List of commited shaders.
+ * @dev_priv: Pointer to a device private structure.
+ *
+ * @shaders and @list are protected by the cmdbuf mutex for now.
+ */
+struct vmw_compat_shader_manager {
+	struct drm_open_hash shaders;
+	struct list_head list;
+	struct vmw_private *dev_priv;
+};
+
 static void vmw_user_shader_free(struct vmw_resource *res);
 static struct vmw_resource *
 vmw_user_shader_base_to_res(struct ttm_base_object *base);
@@ -325,13 +371,81 @@ int vmw_shader_destroy_ioctl(struct drm_device *dev, void *data,
 					 TTM_REF_USAGE);
 }
 
+int vmw_shader_alloc(struct vmw_private *dev_priv,
+		     struct vmw_dma_buffer *buffer,
+		     size_t shader_size,
+		     size_t offset,
+		     SVGA3dShaderType shader_type,
+		     struct ttm_object_file *tfile,
+		     u32 *handle)
+{
+	struct vmw_user_shader *ushader;
+	struct vmw_resource *res, *tmp;
+	int ret;
+
+	/*
+	 * Approximate idr memory usage with 128 bytes. It will be limited
+	 * by maximum number_of shaders anyway.
+	 */
+	if (unlikely(vmw_user_shader_size == 0))
+		vmw_user_shader_size =
+			ttm_round_pot(sizeof(struct vmw_user_shader)) + 128;
+
+	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv),
+				   vmw_user_shader_size,
+				   false, true);
+	if (unlikely(ret != 0)) {
+		if (ret != -ERESTARTSYS)
+			DRM_ERROR("Out of graphics memory for shader "
+				  "creation.\n");
+		goto out;
+	}
+
+	ushader = kzalloc(sizeof(*ushader), GFP_KERNEL);
+	if (unlikely(ushader == NULL)) {
+		ttm_mem_global_free(vmw_mem_glob(dev_priv),
+				    vmw_user_shader_size);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	res = &ushader->shader.res;
+	ushader->base.shareable = false;
+	ushader->base.tfile = NULL;
+
+	/*
+	 * From here on, the destructor takes over resource freeing.
+	 */
+
+	ret = vmw_gb_shader_init(dev_priv, res, shader_size,
+				 offset, shader_type, buffer,
+				 vmw_user_shader_free);
+	if (unlikely(ret != 0))
+		goto out;
+
+	tmp = vmw_resource_reference(res);
+	ret = ttm_base_object_init(tfile, &ushader->base, false,
+				   VMW_RES_SHADER,
+				   &vmw_user_shader_base_release, NULL);
+
+	if (unlikely(ret != 0)) {
+		vmw_resource_unreference(&tmp);
+		goto out_err;
+	}
+
+	if (handle)
+		*handle = ushader->base.hash.key;
+out_err:
+	vmw_resource_unreference(&res);
+out:
+	return ret;
+}
+
+
 int vmw_shader_define_ioctl(struct drm_device *dev, void *data,
 			     struct drm_file *file_priv)
 {
 	struct vmw_private *dev_priv = vmw_priv(dev);
-	struct vmw_user_shader *ushader;
-	struct vmw_resource *res;
-	struct vmw_resource *tmp;
 	struct drm_vmw_shader_create_arg *arg =
 		(struct drm_vmw_shader_create_arg *)data;
 	struct ttm_object_file *tfile = vmw_fpriv(file_priv)->tfile;
@@ -373,69 +487,324 @@ int vmw_shader_define_ioctl(struct drm_device *dev, void *data,
 		goto out_bad_arg;
 	}
 
-	/*
-	 * Approximate idr memory usage with 128 bytes. It will be limited
-	 * by maximum number_of shaders anyway.
-	 */
+	ret = ttm_read_lock(&vmaster->lock, true);
+	if (unlikely(ret != 0))
+		goto out_bad_arg;
 
-	if (unlikely(vmw_user_shader_size == 0))
-		vmw_user_shader_size = ttm_round_pot(sizeof(*ushader))
-			+ 128;
+	ret = vmw_shader_alloc(dev_priv, buffer, arg->size, arg->offset,
+			       shader_type, tfile, &arg->shader_handle);
 
-	ret = ttm_read_lock(&vmaster->lock, true);
+	ttm_read_unlock(&vmaster->lock);
+out_bad_arg:
+	vmw_dmabuf_unreference(&buffer);
+	return ret;
+}
+
+/**
+ * vmw_compat_shader_lookup - Look up a compat shader
+ *
+ * @man: Pointer to the compat shader manager.
+ * @shader_type: The shader type, that combined with the user_key identifies
+ * the shader.
+ * @user_key: On entry, this should be a pointer to the user_key.
+ * On successful exit, it will contain the guest-backed shader's TTM handle.
+ *
+ * Returns 0 on success. Non-zero on failure, in which case the value pointed
+ * to by @user_key is unmodified.
+ */
+int vmw_compat_shader_lookup(struct vmw_compat_shader_manager *man,
+			     SVGA3dShaderType shader_type,
+			     u32 *user_key)
+{
+	struct drm_hash_item *hash;
+	int ret;
+	unsigned long key = *user_key | (shader_type << 24);
+
+	ret = drm_ht_find_item(&man->shaders, key, &hash);
 	if (unlikely(ret != 0))
 		return ret;
 
-	ret = ttm_mem_global_alloc(vmw_mem_glob(dev_priv),
-				   vmw_user_shader_size,
-				   false, true);
-	if (unlikely(ret != 0)) {
-		if (ret != -ERESTARTSYS)
-			DRM_ERROR("Out of graphics memory for shader"
-				  " creation.\n");
-		goto out_unlock;
+	*user_key = drm_hash_entry(hash, struct vmw_compat_shader,
+				   hash)->handle;
+
+	return 0;
+}
+
+/**
+ * vmw_compat_shader_free - Free a compat shader.
+ *
+ * @man: Pointer to the compat shader manager.
+ * @entry: Pointer to a struct vmw_compat_shader.
+ *
+ * Frees a struct vmw_compat_shder entry and drops its reference to the
+ * guest backed shader.
+ */
+static void vmw_compat_shader_free(struct vmw_compat_shader_manager *man,
+				   struct vmw_compat_shader *entry)
+{
+	list_del(&entry->head);
+	WARN_ON(drm_ht_remove_item(&man->shaders, &entry->hash));
+	WARN_ON(ttm_ref_object_base_unref(entry->tfile, entry->handle,
+					  TTM_REF_USAGE));
+	kfree(entry);
+}
+
+/**
+ * vmw_compat_shaders_commit - Commit a list of compat shader actions.
+ *
+ * @man: Pointer to the compat shader manager.
+ * @list: Caller's list of compat shader actions.
+ *
+ * This function commits a list of compat shader additions or removals.
+ * It is typically called when the execbuf ioctl call triggering these
+ * actions has commited the fifo contents to the device.
+ */
+void vmw_compat_shaders_commit(struct vmw_compat_shader_manager *man,
+			       struct list_head *list)
+{
+	struct vmw_compat_shader *entry, *next;
+
+	list_for_each_entry_safe(entry, next, list, head) {
+		list_del(&entry->head);
+		switch (entry->state) {
+		case VMW_COMPAT_ADD:
+			entry->state = VMW_COMPAT_COMMITED;
+			list_add_tail(&entry->head, &man->list);
+			break;
+		case VMW_COMPAT_DEL:
+			ttm_ref_object_base_unref(entry->tfile, entry->handle,
+						  TTM_REF_USAGE);
+			kfree(entry);
+			break;
+		default:
+			BUG();
+			break;
+		}
 	}
+}
 
-	ushader = kzalloc(sizeof(*ushader), GFP_KERNEL);
-	if (unlikely(ushader == NULL)) {
-		ttm_mem_global_free(vmw_mem_glob(dev_priv),
-				    vmw_user_shader_size);
-		ret = -ENOMEM;
-		goto out_unlock;
+/**
+ * vmw_compat_shaders_revert - Revert a list of compat shader actions
+ *
+ * @man: Pointer to the compat shader manager.
+ * @list: Caller's list of compat shader actions.
+ *
+ * This function reverts a list of compat shader additions or removals.
+ * It is typically called when the execbuf ioctl call triggering these
+ * actions failed for some reason, and the command stream was never
+ * submitted.
+ */
+void vmw_compat_shaders_revert(struct vmw_compat_shader_manager *man,
+			       struct list_head *list)
+{
+	struct vmw_compat_shader *entry, *next;
+	int ret;
+
+	list_for_each_entry_safe(entry, next, list, head) {
+		switch (entry->state) {
+		case VMW_COMPAT_ADD:
+			vmw_compat_shader_free(man, entry);
+			break;
+		case VMW_COMPAT_DEL:
+			ret = drm_ht_insert_item(&man->shaders, &entry->hash);
+			list_del(&entry->head);
+			list_add_tail(&entry->head, &man->list);
+			entry->state = VMW_COMPAT_COMMITED;
+			break;
+		default:
+			BUG();
+			break;
+		}
 	}
+}
 
-	res = &ushader->shader.res;
-	ushader->base.shareable = false;
-	ushader->base.tfile = NULL;
+/**
+ * vmw_compat_shader_remove - Stage a compat shader for removal.
+ *
+ * @man: Pointer to the compat shader manager
+ * @user_key: The key that is used to identify the shader. The key is
+ * unique to the shader type.
+ * @shader_type: Shader type.
+ * @list: Caller's list of staged shader actions.
+ *
+ * This function stages a compat shader for removal and removes the key from
+ * the shader manager's hash table. If the shader was previously only staged
+ * for addition it is completely removed (But the execbuf code may keep a
+ * reference if it was bound to a context between addition and removal). If
+ * it was previously commited to the manager, it is staged for removal.
+ */
+int vmw_compat_shader_remove(struct vmw_compat_shader_manager *man,
+			     u32 user_key, SVGA3dShaderType shader_type,
+			     struct list_head *list)
+{
+	struct vmw_compat_shader *entry;
+	struct drm_hash_item *hash;
+	int ret;
 
-	/*
-	 * From here on, the destructor takes over resource freeing.
-	 */
+	ret = drm_ht_find_item(&man->shaders, user_key | (shader_type << 24),
+			       &hash);
+	if (likely(ret != 0))
+		return -EINVAL;
 
-	ret = vmw_gb_shader_init(dev_priv, res, arg->size,
-				 arg->offset, shader_type, buffer,
-				 vmw_user_shader_free);
+	entry = drm_hash_entry(hash, struct vmw_compat_shader, hash);
+
+	switch (entry->state) {
+	case VMW_COMPAT_ADD:
+		vmw_compat_shader_free(man, entry);
+		break;
+	case VMW_COMPAT_COMMITED:
+		(void) drm_ht_remove_item(&man->shaders, &entry->hash);
+		list_del(&entry->head);
+		entry->state = VMW_COMPAT_DEL;
+		list_add_tail(&entry->head, list);
+		break;
+	default:
+		BUG();
+		break;
+	}
+
+	return 0;
+}
+
+/**
+ * vmw_compat_shader_add - Create a compat shader and add the
+ * key to the manager
+ *
+ * @man: Pointer to the compat shader manager
+ * @user_key: The key that is used to identify the shader. The key is
+ * unique to the shader type.
+ * @bytecode: Pointer to the bytecode of the shader.
+ * @shader_type: Shader type.
+ * @tfile: Pointer to a struct ttm_object_file that the guest-backed shader is
+ * to be created with.
+ * @list: Caller's list of staged shader actions.
+ *
+ * Note that only the key is added to the shader manager's hash table.
+ * The shader is not yet added to the shader manager's list of shaders.
+ */
+int vmw_compat_shader_add(struct vmw_compat_shader_manager *man,
+			  u32 user_key, const void *bytecode,
+			  SVGA3dShaderType shader_type,
+			  size_t size,
+			  struct ttm_object_file *tfile,
+			  struct list_head *list)
+{
+	struct vmw_dma_buffer *buf;
+	struct ttm_bo_kmap_obj map;
+	bool is_iomem;
+	struct vmw_compat_shader *compat;
+	u32 handle;
+	int ret;
+
+	if (user_key > ((1 << 24) - 1) || (unsigned) shader_type > 16)
+		return -EINVAL;
+
+	/* Allocate and pin a DMA buffer */
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+	if (unlikely(buf == NULL))
+		return -ENOMEM;
+
+	ret = vmw_dmabuf_init(man->dev_priv, buf, size, &vmw_sys_ne_placement,
+			      true, vmw_dmabuf_bo_free);
 	if (unlikely(ret != 0))
-		goto out_unlock;
+		goto out;
 
-	tmp = vmw_resource_reference(res);
-	ret = ttm_base_object_init(tfile, &ushader->base, false,
-				   VMW_RES_SHADER,
-				   &vmw_user_shader_base_release, NULL);
+	ret = ttm_bo_reserve(&buf->base, false, true, false, NULL);
+	if (unlikely(ret != 0))
+		goto no_reserve;
 
+	/* Map and copy shader bytecode. */
+	ret = ttm_bo_kmap(&buf->base, 0, PAGE_ALIGN(size) >> PAGE_SHIFT,
+			  &map);
 	if (unlikely(ret != 0)) {
-		vmw_resource_unreference(&tmp);
-		goto out_err;
+		ttm_bo_unreserve(&buf->base);
+		goto no_reserve;
 	}
 
-	arg->shader_handle = ushader->base.hash.key;
-out_err:
-	vmw_resource_unreference(&res);
-out_unlock:
-	ttm_read_unlock(&vmaster->lock);
-out_bad_arg:
-	vmw_dmabuf_unreference(&buffer);
+	memcpy(ttm_kmap_obj_virtual(&map, &is_iomem), bytecode, size);
+	WARN_ON(is_iomem);
+
+	ttm_bo_kunmap(&map);
+	ret = ttm_bo_validate(&buf->base, &vmw_sys_placement, false, true);
+	WARN_ON(ret != 0);
+	ttm_bo_unreserve(&buf->base);
+
+	/* Create a guest-backed shader container backed by the dma buffer */
+	ret = vmw_shader_alloc(man->dev_priv, buf, size, 0, shader_type,
+			       tfile, &handle);
+	vmw_dmabuf_unreference(&buf);
+	if (unlikely(ret != 0))
+		goto no_reserve;
+	/*
+	 * Create a compat shader structure and stage it for insertion
+	 * in the manager
+	 */
+	compat = kzalloc(sizeof(*compat), GFP_KERNEL);
+	if (compat == NULL)
+		goto no_compat;
+
+	compat->hash.key = user_key |  (shader_type << 24);
+	ret = drm_ht_insert_item(&man->shaders, &compat->hash);
+	if (unlikely(ret != 0))
+		goto out_invalid_key;
+
+	compat->state = VMW_COMPAT_ADD;
+	compat->handle = handle;
+	compat->tfile = tfile;
+	list_add_tail(&compat->head, list);
 
+	return 0;
+
+out_invalid_key:
+	kfree(compat);
+no_compat:
+	ttm_ref_object_base_unref(tfile, handle, TTM_REF_USAGE);
+no_reserve:
+out:
 	return ret;
+}
+
+/**
+ * vmw_compat_shader_man_create - Create a compat shader manager
+ *
+ * @dev_priv: Pointer to a device private structure.
+ *
+ * Typically done at file open time. If successful returns a pointer to a
+ * compat shader manager. Otherwise returns an error pointer.
+ */
+struct vmw_compat_shader_manager *
+vmw_compat_shader_man_create(struct vmw_private *dev_priv)
+{
+	struct vmw_compat_shader_manager *man;
+	int ret;
+
+	man = kzalloc(sizeof(*man), GFP_KERNEL);
+
+	man->dev_priv = dev_priv;
+	INIT_LIST_HEAD(&man->list);
+	ret = drm_ht_create(&man->shaders, VMW_COMPAT_SHADER_HT_ORDER);
+	if (ret == 0)
+		return man;
+
+	kfree(man);
+	return ERR_PTR(ret);
+}
+
+/**
+ * vmw_compat_shader_man_destroy - Destroy a compat shader manager
+ *
+ * @man: Pointer to the shader manager to destroy.
+ *
+ * Typically done at file close time.
+ */
+void vmw_compat_shader_man_destroy(struct vmw_compat_shader_manager *man)
+{
+	struct vmw_compat_shader *entry, *next;
+
+	mutex_lock(&man->dev_priv->cmdbuf_mutex);
+	list_for_each_entry_safe(entry, next, &man->list, head)
+		vmw_compat_shader_free(man, entry);
 
+	mutex_unlock(&man->dev_priv->cmdbuf_mutex);
+	kfree(man);
 }