1 files changed, 164 insertions, 103 deletions

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 2a54f86856af..21809a82187b 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -29,6 +29,7 @@
 #include <linux/export.h>
 #include <linux/dma-buf.h>
 #include <linux/rbtree.h>
+#include <linux/module.h>
 
 #include <drm/drm.h>
 #include <drm/drm_drv.h>
@@ -36,9 +37,12 @@
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_prime.h>
+#include <drm/drm_print.h>
 
 #include "drm_internal.h"
 
+MODULE_IMPORT_NS("DMA_BUF");
+
 /**
  * DOC: overview and lifetime rules
  *
@@ -48,15 +52,10 @@
  * between applications, they can't be guessed like the globally unique GEM
  * names.
  *
- * Drivers that support the PRIME API implement the
- * &drm_driver.prime_handle_to_fd and &drm_driver.prime_fd_to_handle operations.
- * GEM based drivers must use drm_gem_prime_handle_to_fd() and
- * drm_gem_prime_fd_to_handle() to implement these. For GEM based drivers the
- * actual driver interfaces is provided through the &drm_gem_object_funcs.export
- * and &drm_driver.gem_prime_import hooks.
- *
- * &dma_buf_ops implementations for GEM drivers are all individually exported
- * for drivers which need to overwrite or reimplement some of them.
+ * Drivers that support the PRIME API implement the drm_gem_object_funcs.export
+ * and &drm_driver.gem_prime_import hooks. &dma_buf_ops implementations for
+ * drivers are all individually exported for drivers which need to overwrite
+ * or reimplement some of them.
  *
  * Reference Counting for GEM Drivers
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -73,7 +72,7 @@
  * Thus the chain of references always flows in one direction, avoiding loops:
  * importing GEM object -> dma-buf -> exported GEM bo. A further complication
  * are the lookup caches for import and export. These are required to guarantee
- * that any given object will always have only one uniqe userspace handle. This
+ * that any given object will always have only one unique userspace handle. This
  * is required to allow userspace to detect duplicated imports, since some GEM
  * drivers do fail command submissions if a given buffer object is listed more
  * than once. These import and export caches in &drm_prime_file_private only
@@ -95,7 +94,7 @@ struct drm_prime_member {
 	struct rb_node handle_rb;
 };
 
-static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv,
+int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv,
 				    struct dma_buf *dma_buf, uint32_t handle)
 {
 	struct drm_prime_member *member;
@@ -187,24 +186,24 @@ static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpri
 	return -ENOENT;
 }
 
-void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpriv,
-					struct dma_buf *dma_buf)
+void drm_prime_remove_buf_handle(struct drm_prime_file_private *prime_fpriv,
+				 uint32_t handle)
 {
 	struct rb_node *rb;
 
-	rb = prime_fpriv->dmabufs.rb_node;
+	rb = prime_fpriv->handles.rb_node;
 	while (rb) {
 		struct drm_prime_member *member;
 
-		member = rb_entry(rb, struct drm_prime_member, dmabuf_rb);
-		if (member->dma_buf == dma_buf) {
+		member = rb_entry(rb, struct drm_prime_member, handle_rb);
+		if (member->handle == handle) {
 			rb_erase(&member->handle_rb, &prime_fpriv->handles);
 			rb_erase(&member->dmabuf_rb, &prime_fpriv->dmabufs);
 
-			dma_buf_put(dma_buf);
+			dma_buf_put(member->dma_buf);
 			kfree(member);
-			return;
-		} else if (member->dma_buf < dma_buf) {
+			break;
+		} else if (member->handle < handle) {
 			rb = rb->rb_right;
 		} else {
 			rb = rb->rb_left;
@@ -278,7 +277,7 @@ EXPORT_SYMBOL(drm_gem_dmabuf_release);
 
 /**
  * drm_gem_prime_fd_to_handle - PRIME import function for GEM drivers
- * @dev: dev to export the buffer from
+ * @dev: drm_device to import into
  * @file_priv: drm file-private structure
  * @prime_fd: fd id of the dma-buf which should be imported
  * @handle: pointer to storage for the handle of the imported buffer object
@@ -365,11 +364,12 @@ int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 {
 	struct drm_prime_handle *args = data;
 
-	if (!dev->driver->prime_fd_to_handle)
-		return -ENOSYS;
+	if (dev->driver->prime_fd_to_handle) {
+		return dev->driver->prime_fd_to_handle(dev, file_priv, args->fd,
+						       &args->handle);
+	}
 
-	return dev->driver->prime_fd_to_handle(dev, file_priv,
-			args->fd, &args->handle);
+	return drm_gem_prime_fd_to_handle(dev, file_priv, args->fd, &args->handle);
 }
 
 static struct dma_buf *export_and_register_object(struct drm_device *dev,
@@ -407,22 +407,30 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
 }
 
 /**
- * drm_gem_prime_handle_to_fd - PRIME export function for GEM drivers
+ * drm_gem_prime_handle_to_dmabuf - PRIME export function for GEM drivers
  * @dev: dev to export the buffer from
  * @file_priv: drm file-private structure
  * @handle: buffer handle to export
  * @flags: flags like DRM_CLOEXEC
- * @prime_fd: pointer to storage for the fd id of the create dma-buf
  *
  * This is the PRIME export function which must be used mandatorily by GEM
  * drivers to ensure correct lifetime management of the underlying GEM object.
  * The actual exporting from GEM object to a dma-buf is done through the
  * &drm_gem_object_funcs.export callback.
+ *
+ * Unlike drm_gem_prime_handle_to_fd(), it returns the struct dma_buf it
+ * has created, without attaching it to any file descriptors.  The difference
+ * between those two is similar to that between anon_inode_getfile() and
+ * anon_inode_getfd(); insertion into descriptor table is something you
+ * can not revert if any cleanup is needed, so the descriptor-returning
+ * variants should only be used when you are past the last failure exit
+ * and the only thing left is passing the new file descriptor to userland.
+ * When all you need is the object itself or when you need to do something
+ * else that might fail, use that one instead.
  */
-int drm_gem_prime_handle_to_fd(struct drm_device *dev,
+struct dma_buf *drm_gem_prime_handle_to_dmabuf(struct drm_device *dev,
 			       struct drm_file *file_priv, uint32_t handle,
-			       uint32_t flags,
-			       int *prime_fd)
+			       uint32_t flags)
 {
 	struct drm_gem_object *obj;
 	int ret = 0;
@@ -431,14 +439,14 @@ int drm_gem_prime_handle_to_fd(struct drm_device *dev,
 	mutex_lock(&file_priv->prime.lock);
 	obj = drm_gem_object_lookup(file_priv, handle);
 	if (!obj)  {
-		ret = -ENOENT;
+		dmabuf = ERR_PTR(-ENOENT);
 		goto out_unlock;
 	}
 
 	dmabuf = drm_prime_lookup_buf_by_handle(&file_priv->prime, handle);
 	if (dmabuf) {
 		get_dma_buf(dmabuf);
-		goto out_have_handle;
+		goto out;
 	}
 
 	mutex_lock(&dev->object_name_lock);
@@ -460,7 +468,6 @@ int drm_gem_prime_handle_to_fd(struct drm_device *dev,
 		/* normally the created dma-buf takes ownership of the ref,
 		 * but if that fails then drop the ref
 		 */
-		ret = PTR_ERR(dmabuf);
 		mutex_unlock(&dev->object_name_lock);
 		goto out;
 	}
@@ -475,34 +482,51 @@ out_have_obj:
 	ret = drm_prime_add_buf_handle(&file_priv->prime,
 				       dmabuf, handle);
 	mutex_unlock(&dev->object_name_lock);
-	if (ret)
-		goto fail_put_dmabuf;
-
-out_have_handle:
-	ret = dma_buf_fd(dmabuf, flags);
-	/*
-	 * We must _not_ remove the buffer from the handle cache since the newly
-	 * created dma buf is already linked in the global obj->dma_buf pointer,
-	 * and that is invariant as long as a userspace gem handle exists.
-	 * Closing the handle will clean out the cache anyway, so we don't leak.
-	 */
-	if (ret < 0) {
-		goto fail_put_dmabuf;
-	} else {
-		*prime_fd = ret;
-		ret = 0;
+	if (ret) {
+		dma_buf_put(dmabuf);
+		dmabuf = ERR_PTR(ret);
 	}
-
-	goto out;
-
-fail_put_dmabuf:
-	dma_buf_put(dmabuf);
 out:
 	drm_gem_object_put(obj);
 out_unlock:
 	mutex_unlock(&file_priv->prime.lock);
+	return dmabuf;
+}
+EXPORT_SYMBOL(drm_gem_prime_handle_to_dmabuf);
 
-	return ret;
+/**
+ * drm_gem_prime_handle_to_fd - PRIME export function for GEM drivers
+ * @dev: dev to export the buffer from
+ * @file_priv: drm file-private structure
+ * @handle: buffer handle to export
+ * @flags: flags like DRM_CLOEXEC
+ * @prime_fd: pointer to storage for the fd id of the create dma-buf
+ *
+ * This is the PRIME export function which must be used mandatorily by GEM
+ * drivers to ensure correct lifetime management of the underlying GEM object.
+ * The actual exporting from GEM object to a dma-buf is done through the
+ * &drm_gem_object_funcs.export callback.
+ */
+int drm_gem_prime_handle_to_fd(struct drm_device *dev,
+			       struct drm_file *file_priv, uint32_t handle,
+			       uint32_t flags,
+			       int *prime_fd)
+{
+	struct dma_buf *dmabuf;
+	int fd = get_unused_fd_flags(flags);
+
+	if (fd < 0)
+		return fd;
+
+	dmabuf = drm_gem_prime_handle_to_dmabuf(dev, file_priv, handle, flags);
+	if (IS_ERR(dmabuf)) {
+		put_unused_fd(fd);
+		return PTR_ERR(dmabuf);
+	}
+
+	fd_install(fd, dmabuf->file);
+	*prime_fd = fd;
+	return 0;
 }
 EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
 
@@ -511,15 +535,17 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 {
 	struct drm_prime_handle *args = data;
 
-	if (!dev->driver->prime_handle_to_fd)
-		return -ENOSYS;
-
 	/* check flags are valid */
 	if (args->flags & ~(DRM_CLOEXEC | DRM_RDWR))
 		return -EINVAL;
 
-	return dev->driver->prime_handle_to_fd(dev, file_priv,
-			args->handle, args->flags, &args->fd);
+	if (dev->driver->prime_handle_to_fd) {
+		return dev->driver->prime_handle_to_fd(dev, file_priv,
+						       args->handle, args->flags,
+						       &args->fd);
+	}
+	return drm_gem_prime_handle_to_fd(dev, file_priv, args->handle,
+					  args->flags, &args->fd);
 }
 
 /**
@@ -537,7 +563,8 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
  * Optional pinning of buffers is handled at dma-buf attach and detach time in
  * drm_gem_map_attach() and drm_gem_map_detach(). Backing storage itself is
  * handled by drm_gem_map_dma_buf() and drm_gem_unmap_dma_buf(), which relies on
- * &drm_gem_object_funcs.get_sg_table.
+ * &drm_gem_object_funcs.get_sg_table. If &drm_gem_object_funcs.get_sg_table is
+ * unimplemented, exports into another device are rejected.
  *
  * For kernel-internal access there's drm_gem_dmabuf_vmap() and
  * drm_gem_dmabuf_vunmap(). Userspace mmap support is provided by
@@ -549,7 +576,7 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
  *
  * FIXME: The underlying helper functions are named rather inconsistently.
  *
- * Exporting buffers
+ * Importing buffers
  * ~~~~~~~~~~~~~~~~~
  *
  * Importing dma-bufs using drm_gem_prime_import() relies on
@@ -575,8 +602,26 @@ int drm_gem_map_attach(struct dma_buf *dma_buf,
 		       struct dma_buf_attachment *attach)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
+	int ret;
+
+	/*
+	 * drm_gem_map_dma_buf() requires obj->get_sg_table(), but drivers
+	 * that implement their own ->map_dma_buf() do not.
+	 */
+	if (dma_buf->ops->map_dma_buf == drm_gem_map_dma_buf &&
+	    !obj->funcs->get_sg_table)
+		return -ENOSYS;
+
+	if (!obj->funcs->pin)
+		return 0;
+
+	ret = dma_resv_lock(obj->resv, NULL);
+	if (ret)
+		return ret;
+	ret = obj->funcs->pin(obj);
+	dma_resv_unlock(obj->resv);
 
-	return drm_gem_pin(obj);
+	return ret;
 }
 EXPORT_SYMBOL(drm_gem_map_attach);
 
@@ -593,8 +638,16 @@ void drm_gem_map_detach(struct dma_buf *dma_buf,
 			struct dma_buf_attachment *attach)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
+	int ret;
+
+	if (!obj->funcs->unpin)
+		return;
 
-	drm_gem_unpin(obj);
+	ret = dma_resv_lock(obj->resv, NULL);
+	if (drm_WARN_ON(obj->dev, ret))
+		return;
+	obj->funcs->unpin(obj);
+	dma_resv_unlock(obj->resv);
 }
 EXPORT_SYMBOL(drm_gem_map_detach);
 
@@ -671,11 +724,11 @@ EXPORT_SYMBOL(drm_gem_unmap_dma_buf);
  *
  * Returns 0 on success or a negative errno code otherwise.
  */
-int drm_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
+int drm_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct iosys_map *map)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
 
-	return drm_gem_vmap(obj, map);
+	return drm_gem_vmap_locked(obj, map);
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
 
@@ -687,11 +740,11 @@ EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
  * Releases a kernel virtual mapping. This can be used as the
  * &dma_buf_ops.vunmap callback. Calls into &drm_gem_object_funcs.vunmap for device specific handling.
  */
-void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
+void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct iosys_map *map)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
 
-	drm_gem_vunmap(obj, map);
+	drm_gem_vunmap_locked(obj, map);
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
 
@@ -704,8 +757,6 @@ EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
  * the same codepath that is used for regular GEM buffer mapping on the DRM fd.
  * The fake GEM offset is added to vma->vm_pgoff and &drm_driver->fops->mmap is
  * called to set up the mapping.
- *
- * Drivers can use this as their &drm_driver.gem_prime_mmap callback.
  */
 int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 {
@@ -719,11 +770,13 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 	if (obj->funcs && obj->funcs->mmap) {
 		vma->vm_ops = obj->funcs->vm_ops;
 
+		drm_gem_object_get(obj);
 		ret = obj->funcs->mmap(obj, vma);
-		if (ret)
+		if (ret) {
+			drm_gem_object_put(obj);
 			return ret;
+		}
 		vma->vm_private_data = obj;
-		drm_gem_object_get(obj);
 		return 0;
 	}
 
@@ -759,28 +812,19 @@ EXPORT_SYMBOL(drm_gem_prime_mmap);
  * @vma: virtual address range
  *
  * Provides memory mapping for the buffer. This can be used as the
- * &dma_buf_ops.mmap callback. It just forwards to &drm_driver.gem_prime_mmap,
- * which should be set to drm_gem_prime_mmap().
- *
- * FIXME: There's really no point to this wrapper, drivers which need anything
- * else but drm_gem_prime_mmap can roll their own &dma_buf_ops.mmap callback.
+ * &dma_buf_ops.mmap callback. It just forwards to drm_gem_prime_mmap().
  *
  * Returns 0 on success or a negative error code on failure.
  */
 int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
-	struct drm_device *dev = obj->dev;
-
-	if (!dev->driver->gem_prime_mmap)
-		return -ENOSYS;
 
-	return dev->driver->gem_prime_mmap(obj, vma);
+	return drm_gem_prime_mmap(obj, vma);
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_mmap);
 
 static const struct dma_buf_ops drm_gem_prime_dmabuf_ops =  {
-	.cache_sgt_mapping = true,
 	.attach = drm_gem_map_attach,
 	.detach = drm_gem_map_detach,
 	.map_dma_buf = drm_gem_map_dma_buf,
@@ -807,8 +851,8 @@ struct sg_table *drm_prime_pages_to_sg(struct drm_device *dev,
 				       struct page **pages, unsigned int nr_pages)
 {
 	struct sg_table *sg;
-	struct scatterlist *sge;
 	size_t max_segment = 0;
+	int err;
 
 	sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
 	if (!sg)
@@ -818,13 +862,12 @@ struct sg_table *drm_prime_pages_to_sg(struct drm_device *dev,
 		max_segment = dma_max_mapping_size(dev->dev);
 	if (max_segment == 0)
 		max_segment = UINT_MAX;
-	sge = __sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
-					  nr_pages << PAGE_SHIFT,
-					  max_segment,
-					  NULL, 0, GFP_KERNEL);
-	if (IS_ERR(sge)) {
+	err = sg_alloc_table_from_pages_segment(sg, pages, nr_pages, 0,
+						(unsigned long)nr_pages << PAGE_SHIFT,
+						max_segment, GFP_KERNEL);
+	if (err) {
 		kfree(sg);
-		sg = ERR_CAST(sge);
+		sg = ERR_PTR(err);
 	}
 	return sg;
 }
@@ -835,7 +878,7 @@ EXPORT_SYMBOL(drm_prime_pages_to_sg);
  * @sgt: sg_table describing the buffer to check
  *
  * This helper calculates the contiguous size in the DMA address space
- * of the the buffer described by the provided sg_table.
+ * of the buffer described by the provided sg_table.
  *
  * This is useful for implementing
  * &drm_gem_object_funcs.gem_prime_import_sg_table.
@@ -888,6 +931,26 @@ struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj,
 }
 EXPORT_SYMBOL(drm_gem_prime_export);
 
+
+/**
+ * drm_gem_is_prime_exported_dma_buf -
+ * checks if the DMA-BUF was exported from a GEM object belonging to @dev.
+ * @dev: drm_device to check against
+ * @dma_buf: dma-buf object to import
+ *
+ * Return: true if the DMA-BUF was exported from a GEM object belonging
+ * to @dev, false otherwise.
+ */
+
+bool drm_gem_is_prime_exported_dma_buf(struct drm_device *dev,
+				       struct dma_buf *dma_buf)
+{
+	struct drm_gem_object *obj = dma_buf->priv;
+
+	return (dma_buf->ops == &drm_gem_prime_dmabuf_ops) && (obj->dev == dev);
+}
+EXPORT_SYMBOL(drm_gem_is_prime_exported_dma_buf);
+
 /**
  * drm_gem_prime_import_dev - core implementation of the import callback
  * @dev: drm_device to import into
@@ -911,16 +974,14 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
 	struct drm_gem_object *obj;
 	int ret;
 
-	if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) {
+	if (drm_gem_is_prime_exported_dma_buf(dev, dma_buf)) {
+		/*
+		 * Importing dmabuf exported from our own gem increases
+		 * refcount on gem itself instead of f_count of dmabuf.
+		 */
 		obj = dma_buf->priv;
-		if (obj->dev == dev) {
-			/*
-			 * Importing dmabuf exported from out own gem increases
-			 * refcount on gem itself instead of f_count of dmabuf.
-			 */
-			drm_gem_object_get(obj);
-			return obj;
-		}
+		drm_gem_object_get(obj);
+		return obj;
 	}
 
 	if (!dev->driver->gem_prime_import_sg_table)
@@ -932,7 +993,7 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
 
 	get_dma_buf(dma_buf);
 
-	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+	sgt = dma_buf_map_attachment_unlocked(attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(sgt)) {
 		ret = PTR_ERR(sgt);
 		goto fail_detach;
@@ -950,7 +1011,7 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
 	return obj;
 
 fail_unmap:
-	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+	dma_buf_unmap_attachment_unlocked(attach, sgt, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
 	dma_buf_put(dma_buf);
@@ -975,7 +1036,7 @@ EXPORT_SYMBOL(drm_gem_prime_import_dev);
 struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
 					    struct dma_buf *dma_buf)
 {
-	return drm_gem_prime_import_dev(dev, dma_buf, dev->dev);
+	return drm_gem_prime_import_dev(dev, dma_buf, drm_dev_dma_dev(dev));
 }
 EXPORT_SYMBOL(drm_gem_prime_import);
 
@@ -1048,7 +1109,7 @@ void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg)
 
 	attach = obj->import_attach;
 	if (sg)
-		dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
+		dma_buf_unmap_attachment_unlocked(attach, sg, DMA_BIDIRECTIONAL);
 	dma_buf = attach->dmabuf;
 	dma_buf_detach(attach->dmabuf, attach);
 	/* remove the reference */