1 files changed, 113 insertions, 59 deletions

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index df31e5782eed..4b7cfbac4daa 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -35,22 +35,12 @@ static const struct drm_gem_object_funcs drm_gem_shmem_funcs = {
 	.mmap = drm_gem_shmem_mmap,
 };
 
-/**
- * drm_gem_shmem_create - Allocate an object with the given size
- * @dev: DRM device
- * @size: Size of the object to allocate
- *
- * This function creates a shmem GEM object.
- *
- * Returns:
- * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative
- * error code on failure.
- */
-struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)
+static struct drm_gem_shmem_object *
+__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
 {
 	struct drm_gem_shmem_object *shmem;
 	struct drm_gem_object *obj;
-	int ret;
+	int ret = 0;
 
 	size = PAGE_ALIGN(size);
 
@@ -64,7 +54,10 @@ struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t
 	if (!obj->funcs)
 		obj->funcs = &drm_gem_shmem_funcs;
 
-	ret = drm_gem_object_init(dev, obj, size);
+	if (private)
+		drm_gem_private_object_init(dev, obj, size);
+	else
+		ret = drm_gem_object_init(dev, obj, size);
 	if (ret)
 		goto err_free;
 
@@ -77,15 +70,17 @@ struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t
 	mutex_init(&shmem->vmap_lock);
 	INIT_LIST_HEAD(&shmem->madv_list);
 
-	/*
-	 * Our buffers are kept pinned, so allocating them
-	 * from the MOVABLE zone is a really bad idea, and
-	 * conflicts with CMA. See comments above new_inode()
-	 * why this is required _and_ expected if you're
-	 * going to pin these pages.
-	 */
-	mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER |
-			     __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+	if (!private) {
+		/*
+		 * Our buffers are kept pinned, so allocating them
+		 * from the MOVABLE zone is a really bad idea, and
+		 * conflicts with CMA. See comments above new_inode()
+		 * why this is required _and_ expected if you're
+		 * going to pin these pages.
+		 */
+		mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER |
+				     __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+	}
 
 	return shmem;
 
@@ -96,6 +91,21 @@ err_free:
 
 	return ERR_PTR(ret);
 }
+/**
+ * drm_gem_shmem_create - Allocate an object with the given size
+ * @dev: DRM device
+ * @size: Size of the object to allocate
+ *
+ * This function creates a shmem GEM object.
+ *
+ * Returns:
+ * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)
+{
+	return __drm_gem_shmem_create(dev, size, false);
+}
 EXPORT_SYMBOL_GPL(drm_gem_shmem_create);
 
 /**
@@ -103,7 +113,8 @@ EXPORT_SYMBOL_GPL(drm_gem_shmem_create);
  * @obj: GEM object to free
  *
  * This function cleans up the GEM object state and frees the memory used to
- * store the object itself.
+ * store the object itself. It should be used to implement
+ * &drm_gem_object_funcs.free.
  */
 void drm_gem_shmem_free_object(struct drm_gem_object *obj)
 {
@@ -112,9 +123,7 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj)
 	WARN_ON(shmem->vmap_use_count);
 
 	if (obj->import_attach) {
-		shmem->pages_use_count--;
 		drm_prime_gem_destroy(obj, shmem->sgt);
-		kvfree(shmem->pages);
 	} else {
 		if (shmem->sgt) {
 			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
@@ -169,6 +178,8 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 {
 	int ret;
 
+	WARN_ON(shmem->base.import_attach);
+
 	ret = mutex_lock_interruptible(&shmem->pages_lock);
 	if (ret)
 		return ret;
@@ -214,7 +225,8 @@ EXPORT_SYMBOL(drm_gem_shmem_put_pages);
  * @obj: GEM object
  *
  * This function makes sure the backing pages are pinned in memory while the
- * buffer is exported.
+ * buffer is exported. It should only be used to implement
+ * &drm_gem_object_funcs.pin.
  *
  * Returns:
  * 0 on success or a negative error code on failure.
@@ -223,6 +235,8 @@ int drm_gem_shmem_pin(struct drm_gem_object *obj)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
+	WARN_ON(shmem->base.import_attach);
+
 	return drm_gem_shmem_get_pages(shmem);
 }
 EXPORT_SYMBOL(drm_gem_shmem_pin);
@@ -232,12 +246,14 @@ EXPORT_SYMBOL(drm_gem_shmem_pin);
  * @obj: GEM object
  *
  * This function removes the requirement that the backing pages are pinned in
- * memory.
+ * memory. It should only be used to implement &drm_gem_object_funcs.unpin.
  */
 void drm_gem_shmem_unpin(struct drm_gem_object *obj)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
+	WARN_ON(shmem->base.import_attach);
+
 	drm_gem_shmem_put_pages(shmem);
 }
 EXPORT_SYMBOL(drm_gem_shmem_unpin);
@@ -250,15 +266,15 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
 	if (shmem->vmap_use_count++ > 0)
 		return shmem->vaddr;
 
-	ret = drm_gem_shmem_get_pages(shmem);
-	if (ret)
-		goto err_zero_use;
-
 	if (obj->import_attach) {
 		shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
+		ret = drm_gem_shmem_get_pages(shmem);
+		if (ret)
+			goto err_zero_use;
+
 		if (!shmem->map_cached)
 			prot = pgprot_writecombine(prot);
 		shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
@@ -274,7 +290,8 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
 	return shmem->vaddr;
 
 err_put_pages:
-	drm_gem_shmem_put_pages(shmem);
+	if (!obj->import_attach)
+		drm_gem_shmem_put_pages(shmem);
 err_zero_use:
 	shmem->vmap_use_count = 0;
 
@@ -285,8 +302,14 @@ err_zero_use:
  * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object
  * @shmem: shmem GEM object
  *
- * This function makes sure that a virtual address exists for the buffer backing
- * the shmem GEM object.
+ * This function makes sure that a contiguous kernel virtual address mapping
+ * exists for the buffer backing the shmem GEM object.
+ *
+ * This function can be used to implement &drm_gem_object_funcs.vmap. But it can
+ * also be called by drivers directly, in which case it will hide the
+ * differences between dma-buf imported and natively allocated objects.
+ *
+ * Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap().
  *
  * Returns:
  * 0 on success or a negative error code on failure.
@@ -330,7 +353,13 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem)
  * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object
  * @shmem: shmem GEM object
  *
- * This function removes the virtual address when use count drops to zero.
+ * This function cleans up a kernel virtual address mapping acquired by
+ * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops to
+ * zero.
+ *
+ * This function can be used to implement &drm_gem_object_funcs.vmap. But it can
+ * also be called by drivers directly, in which case it will hide the
+ * differences between dma-buf imported and natively allocated objects.
  */
 void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr)
 {
@@ -360,7 +389,7 @@ drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
 	 */
 	ret = drm_gem_handle_create(file_priv, &shmem->base, handle);
 	/* drop reference from allocate - handle holds it now. */
-	drm_gem_object_put_unlocked(&shmem->base);
+	drm_gem_object_put(&shmem->base);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -434,6 +463,33 @@ bool drm_gem_shmem_purge(struct drm_gem_object *obj)
 EXPORT_SYMBOL(drm_gem_shmem_purge);
 
 /**
+ * drm_gem_shmem_create_object_cached - Create a shmem buffer object with
+ *                                      cached mappings
+ * @dev: DRM device
+ * @size: Size of the object to allocate
+ *
+ * By default, shmem buffer objects use writecombine mappings. This
+ * function implements struct drm_driver.gem_create_object for shmem
+ * buffer objects with cached mappings.
+ *
+ * Returns:
+ * A struct drm_gem_shmem_object * on success or NULL negative on failure.
+ */
+struct drm_gem_object *
+drm_gem_shmem_create_object_cached(struct drm_device *dev, size_t size)
+{
+	struct drm_gem_shmem_object *shmem;
+
+	shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
+	if (!shmem)
+		return NULL;
+	shmem->map_cached = true;
+
+	return &shmem->base;
+}
+EXPORT_SYMBOL(drm_gem_shmem_create_object_cached);
+
+/**
  * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object
  * @file: DRM file structure to create the dumb buffer for
  * @dev: DRM device
@@ -495,6 +551,8 @@ static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 	int ret;
 
+	WARN_ON(shmem->base.import_attach);
+
 	ret = drm_gem_shmem_get_pages(shmem);
 	WARN_ON_ONCE(ret != 0);
 
@@ -536,6 +594,9 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 	/* Remove the fake offset */
 	vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
 
+	if (obj->import_attach)
+		return dma_buf_mmap(obj->dma_buf, vma, 0);
+
 	shmem = to_drm_gem_shmem_obj(obj);
 
 	ret = drm_gem_shmem_get_pages(shmem);
@@ -559,6 +620,8 @@ EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap);
  * @p: DRM printer
  * @indent: Tab indentation level
  * @obj: GEM object
+ *
+ * This implements the &drm_gem_object_funcs.info callback.
  */
 void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent,
 			      const struct drm_gem_object *obj)
@@ -577,7 +640,12 @@ EXPORT_SYMBOL(drm_gem_shmem_print_info);
  * @obj: GEM object
  *
  * This function exports a scatter/gather table suitable for PRIME usage by
- * calling the standard DMA mapping API.
+ * calling the standard DMA mapping API. Drivers should not call this function
+ * directly, instead it should only be used as an implementation for
+ * &drm_gem_object_funcs.get_sg_table.
+ *
+ * Drivers who need to acquire an scatter/gather table for objects need to call
+ * drm_gem_shmem_get_pages_sgt() instead.
  *
  * Returns:
  * A pointer to the scatter/gather table of pinned pages or NULL on failure.
@@ -586,6 +654,8 @@ struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
+	WARN_ON(shmem->base.import_attach);
+
 	return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
@@ -599,6 +669,10 @@ EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
  * the sg table doesn't exist, the pages are pinned, dma-mapped, and a sg
  * table created.
  *
+ * This is the main function for drivers to get at backing storage, and it hides
+ * and difference between dma-buf imported and natively allocated objects.
+ * drm_gem_shmem_get_sg_table() should not be directly called by drivers.
+ *
  * Returns:
  * A pointer to the scatter/gather table of pinned pages or errno on failure.
  */
@@ -656,36 +730,16 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
 				    struct sg_table *sgt)
 {
 	size_t size = PAGE_ALIGN(attach->dmabuf->size);
-	size_t npages = size >> PAGE_SHIFT;
 	struct drm_gem_shmem_object *shmem;
-	int ret;
 
-	shmem = drm_gem_shmem_create(dev, size);
+	shmem = __drm_gem_shmem_create(dev, size, true);
 	if (IS_ERR(shmem))
 		return ERR_CAST(shmem);
 
-	shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
-	if (!shmem->pages) {
-		ret = -ENOMEM;
-		goto err_free_gem;
-	}
-
-	ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages);
-	if (ret < 0)
-		goto err_free_array;
-
 	shmem->sgt = sgt;
-	shmem->pages_use_count = 1; /* Permanently pinned from our point of view */
 
 	DRM_DEBUG_PRIME("size = %zu\n", size);
 
 	return &shmem->base;
-
-err_free_array:
-	kvfree(shmem->pages);
-err_free_gem:
-	drm_gem_object_put_unlocked(&shmem->base);
-
-	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);