| /* |
| * Copyright © 2012 Red Hat |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| * |
| * Authors: |
| * Dave Airlie <airlied@redhat.com> |
| * Rob Clark <rob.clark@linaro.org> |
| * |
| */ |
| |
| #include <linux/export.h> |
| #include <linux/dma-buf.h> |
| #include <drm/drmP.h> |
| |
| /* |
| * DMA-BUF/GEM Object references and lifetime overview: |
| * |
| * On the export the dma_buf holds a reference to the exporting GEM |
| * object. It takes this reference in handle_to_fd_ioctl, when it |
| * first calls .prime_export and stores the exporting GEM object in |
| * the dma_buf priv. This reference is released when the dma_buf |
| * object goes away in the driver .release function. |
| * |
| * On the import the importing GEM object holds a reference to the |
| * dma_buf (which in turn holds a ref to the exporting GEM object). |
| * It takes that reference in the fd_to_handle ioctl. |
| * It calls dma_buf_get, creates an attachment to it and stores the |
| * attachment in the GEM object. When this attachment is destroyed |
| * when the imported object is destroyed, we remove the attachment |
| * and drop the reference to the dma_buf. |
| * |
| * Thus the chain of references always flows in one direction |
| * (avoiding loops): importing_gem -> dmabuf -> exporting_gem |
| * |
| * Self-importing: if userspace is using PRIME as a replacement for flink |
| * then it will get a fd->handle request for a GEM object that it created. |
| * Drivers should detect this situation and return back the gem object |
| * from the dma-buf private. Prime will do this automatically for drivers that |
| * use the drm_gem_prime_{import,export} helpers. |
| */ |
| |
| struct drm_prime_member { |
| struct list_head entry; |
| struct dma_buf *dma_buf; |
| uint32_t handle; |
| }; |
| static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t handle); |
| |
| static int drm_gem_map_attach(struct dma_buf *dma_buf, |
| struct device *target_dev, |
| struct dma_buf_attachment *attach) |
| { |
| struct drm_gem_object *obj = dma_buf->priv; |
| struct drm_device *dev = obj->dev; |
| |
| if (!dev->driver->gem_prime_pin) |
| return 0; |
| |
| return dev->driver->gem_prime_pin(obj); |
| } |
| |
| static void drm_gem_map_detach(struct dma_buf *dma_buf, |
| struct dma_buf_attachment *attach) |
| { |
| struct drm_gem_object *obj = dma_buf->priv; |
| struct drm_device *dev = obj->dev; |
| |
| if (dev->driver->gem_prime_unpin) |
| dev->driver->gem_prime_unpin(obj); |
| } |
| |
| static struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach, |
| enum dma_data_direction dir) |
| { |
| struct drm_gem_object *obj = attach->dmabuf->priv; |
| struct sg_table *sgt; |
| |
| mutex_lock(&obj->dev->struct_mutex); |
| |
| sgt = obj->dev->driver->gem_prime_get_sg_table(obj); |
| |
| if (!IS_ERR(sgt)) { |
| if (!dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir)) { |
| sg_free_table(sgt); |
| kfree(sgt); |
| sgt = ERR_PTR(-ENOMEM); |
| } |
| } |
| |
| mutex_unlock(&obj->dev->struct_mutex); |
| return sgt; |
| } |
| |
| static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach, |
| struct sg_table *sgt, enum dma_data_direction dir) |
| { |
| dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir); |
| sg_free_table(sgt); |
| kfree(sgt); |
| } |
| |
| static void drm_gem_dmabuf_release(struct dma_buf *dma_buf) |
| { |
| struct drm_gem_object *obj = dma_buf->priv; |
| |
| if (obj->export_dma_buf == dma_buf) { |
| /* drop the reference on the export fd holds */ |
| obj->export_dma_buf = NULL; |
| drm_gem_object_unreference_unlocked(obj); |
| } |
| } |
| |
| static void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf) |
| { |
| struct drm_gem_object *obj = dma_buf->priv; |
| struct drm_device *dev = obj->dev; |
| |
| return dev->driver->gem_prime_vmap(obj); |
| } |
| |
| static void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) |
| { |
| struct drm_gem_object *obj = dma_buf->priv; |
| struct drm_device *dev = obj->dev; |
| |
| dev->driver->gem_prime_vunmap(obj, vaddr); |
| } |
| |
| static void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, |
| unsigned long page_num) |
| { |
| return NULL; |
| } |
| |
| static void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, |
| unsigned long page_num, void *addr) |
| { |
| |
| } |
| static void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf, |
| unsigned long page_num) |
| { |
| return NULL; |
| } |
| |
| static void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, |
| unsigned long page_num, void *addr) |
| { |
| |
| } |
| |
| static int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, |
| struct vm_area_struct *vma) |
| { |
| return -EINVAL; |
| } |
| |
| static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = { |
| .attach = drm_gem_map_attach, |
| .detach = drm_gem_map_detach, |
| .map_dma_buf = drm_gem_map_dma_buf, |
| .unmap_dma_buf = drm_gem_unmap_dma_buf, |
| .release = drm_gem_dmabuf_release, |
| .kmap = drm_gem_dmabuf_kmap, |
| .kmap_atomic = drm_gem_dmabuf_kmap_atomic, |
| .kunmap = drm_gem_dmabuf_kunmap, |
| .kunmap_atomic = drm_gem_dmabuf_kunmap_atomic, |
| .mmap = drm_gem_dmabuf_mmap, |
| .vmap = drm_gem_dmabuf_vmap, |
| .vunmap = drm_gem_dmabuf_vunmap, |
| }; |
| |
| /** |
| * DOC: PRIME Helpers |
| * |
| * Drivers can implement @gem_prime_export and @gem_prime_import in terms of |
| * simpler APIs by using the helper functions @drm_gem_prime_export and |
| * @drm_gem_prime_import. These functions implement dma-buf support in terms of |
| * five lower-level driver callbacks: |
| * |
| * Export callbacks: |
| * |
| * - @gem_prime_pin (optional): prepare a GEM object for exporting |
| * |
| * - @gem_prime_get_sg_table: provide a scatter/gather table of pinned pages |
| * |
| * - @gem_prime_vmap: vmap a buffer exported by your driver |
| * |
| * - @gem_prime_vunmap: vunmap a buffer exported by your driver |
| * |
| * Import callback: |
| * |
| * - @gem_prime_import_sg_table (import): produce a GEM object from another |
| * driver's scatter/gather table |
| */ |
| |
| struct dma_buf *drm_gem_prime_export(struct drm_device *dev, |
| struct drm_gem_object *obj, int flags) |
| { |
| return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size, flags); |
| } |
| EXPORT_SYMBOL(drm_gem_prime_export); |
| |
| 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 drm_gem_object *obj; |
| void *buf; |
| int ret = 0; |
| struct dma_buf *dmabuf; |
| |
| obj = drm_gem_object_lookup(dev, file_priv, handle); |
| if (!obj) |
| return -ENOENT; |
| |
| mutex_lock(&file_priv->prime.lock); |
| /* re-export the original imported object */ |
| if (obj->import_attach) { |
| dmabuf = obj->import_attach->dmabuf; |
| goto out_have_obj; |
| } |
| |
| if (obj->export_dma_buf) { |
| dmabuf = obj->export_dma_buf; |
| goto out_have_obj; |
| } |
| |
| buf = dev->driver->gem_prime_export(dev, obj, flags); |
| if (IS_ERR(buf)) { |
| /* normally the created dma-buf takes ownership of the ref, |
| * but if that fails then drop the ref |
| */ |
| ret = PTR_ERR(buf); |
| goto out; |
| } |
| obj->export_dma_buf = buf; |
| |
| /* if we've exported this buffer the cheat and add it to the import list |
| * so we get the correct handle back |
| */ |
| ret = drm_prime_add_buf_handle(&file_priv->prime, |
| obj->export_dma_buf, handle); |
| if (ret) |
| goto out; |
| |
| *prime_fd = dma_buf_fd(buf, flags); |
| mutex_unlock(&file_priv->prime.lock); |
| return 0; |
| |
| out_have_obj: |
| get_dma_buf(dmabuf); |
| *prime_fd = dma_buf_fd(dmabuf, flags); |
| out: |
| drm_gem_object_unreference_unlocked(obj); |
| mutex_unlock(&file_priv->prime.lock); |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); |
| |
| struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev, |
| struct dma_buf *dma_buf) |
| { |
| struct dma_buf_attachment *attach; |
| struct sg_table *sgt; |
| struct drm_gem_object *obj; |
| int ret; |
| |
| if (!dev->driver->gem_prime_import_sg_table) |
| return ERR_PTR(-EINVAL); |
| |
| if (dma_buf->ops == &drm_gem_prime_dmabuf_ops) { |
| 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_reference(obj); |
| return obj; |
| } |
| } |
| |
| attach = dma_buf_attach(dma_buf, dev->dev); |
| if (IS_ERR(attach)) |
| return ERR_CAST(attach); |
| |
| get_dma_buf(dma_buf); |
| |
| sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL); |
| if (IS_ERR_OR_NULL(sgt)) { |
| ret = PTR_ERR(sgt); |
| goto fail_detach; |
| } |
| |
| obj = dev->driver->gem_prime_import_sg_table(dev, dma_buf->size, sgt); |
| if (IS_ERR(obj)) { |
| ret = PTR_ERR(obj); |
| goto fail_unmap; |
| } |
| |
| obj->import_attach = attach; |
| |
| return obj; |
| |
| fail_unmap: |
| dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); |
| fail_detach: |
| dma_buf_detach(dma_buf, attach); |
| dma_buf_put(dma_buf); |
| |
| return ERR_PTR(ret); |
| } |
| EXPORT_SYMBOL(drm_gem_prime_import); |
| |
| int drm_gem_prime_fd_to_handle(struct drm_device *dev, |
| struct drm_file *file_priv, int prime_fd, uint32_t *handle) |
| { |
| struct dma_buf *dma_buf; |
| struct drm_gem_object *obj; |
| int ret; |
| |
| dma_buf = dma_buf_get(prime_fd); |
| if (IS_ERR(dma_buf)) |
| return PTR_ERR(dma_buf); |
| |
| mutex_lock(&file_priv->prime.lock); |
| |
| ret = drm_prime_lookup_buf_handle(&file_priv->prime, |
| dma_buf, handle); |
| if (!ret) { |
| ret = 0; |
| goto out_put; |
| } |
| |
| /* never seen this one, need to import */ |
| obj = dev->driver->gem_prime_import(dev, dma_buf); |
| if (IS_ERR(obj)) { |
| ret = PTR_ERR(obj); |
| goto out_put; |
| } |
| |
| ret = drm_gem_handle_create(file_priv, obj, handle); |
| drm_gem_object_unreference_unlocked(obj); |
| if (ret) |
| goto out_put; |
| |
| ret = drm_prime_add_buf_handle(&file_priv->prime, |
| dma_buf, *handle); |
| if (ret) |
| goto fail; |
| |
| mutex_unlock(&file_priv->prime.lock); |
| |
| dma_buf_put(dma_buf); |
| |
| return 0; |
| |
| fail: |
| /* hmm, if driver attached, we are relying on the free-object path |
| * to detach.. which seems ok.. |
| */ |
| drm_gem_object_handle_unreference_unlocked(obj); |
| out_put: |
| dma_buf_put(dma_buf); |
| mutex_unlock(&file_priv->prime.lock); |
| return ret; |
| } |
| EXPORT_SYMBOL(drm_gem_prime_fd_to_handle); |
| |
| int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, |
| struct drm_file *file_priv) |
| { |
| struct drm_prime_handle *args = data; |
| uint32_t flags; |
| |
| if (!drm_core_check_feature(dev, DRIVER_PRIME)) |
| return -EINVAL; |
| |
| if (!dev->driver->prime_handle_to_fd) |
| return -ENOSYS; |
| |
| /* check flags are valid */ |
| if (args->flags & ~DRM_CLOEXEC) |
| return -EINVAL; |
| |
| /* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */ |
| flags = args->flags & DRM_CLOEXEC; |
| |
| return dev->driver->prime_handle_to_fd(dev, file_priv, |
| args->handle, flags, &args->fd); |
| } |
| |
| int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data, |
| struct drm_file *file_priv) |
| { |
| struct drm_prime_handle *args = data; |
| |
| if (!drm_core_check_feature(dev, DRIVER_PRIME)) |
| return -EINVAL; |
| |
| if (!dev->driver->prime_fd_to_handle) |
| return -ENOSYS; |
| |
| return dev->driver->prime_fd_to_handle(dev, file_priv, |
| args->fd, &args->handle); |
| } |
| |
| /* |
| * drm_prime_pages_to_sg |
| * |
| * this helper creates an sg table object from a set of pages |
| * the driver is responsible for mapping the pages into the |
| * importers address space |
| */ |
| struct sg_table *drm_prime_pages_to_sg(struct page **pages, int nr_pages) |
| { |
| struct sg_table *sg = NULL; |
| int ret; |
| |
| sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL); |
| if (!sg) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0, |
| nr_pages << PAGE_SHIFT, GFP_KERNEL); |
| if (ret) |
| goto out; |
| |
| return sg; |
| out: |
| kfree(sg); |
| return ERR_PTR(ret); |
| } |
| EXPORT_SYMBOL(drm_prime_pages_to_sg); |
| |
| /* export an sg table into an array of pages and addresses |
| this is currently required by the TTM driver in order to do correct fault |
| handling */ |
| int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages, |
| dma_addr_t *addrs, int max_pages) |
| { |
| unsigned count; |
| struct scatterlist *sg; |
| struct page *page; |
| u32 len, offset; |
| int pg_index; |
| dma_addr_t addr; |
| |
| pg_index = 0; |
| for_each_sg(sgt->sgl, sg, sgt->nents, count) { |
| len = sg->length; |
| offset = sg->offset; |
| page = sg_page(sg); |
| addr = sg_dma_address(sg); |
| |
| while (len > 0) { |
| if (WARN_ON(pg_index >= max_pages)) |
| return -1; |
| pages[pg_index] = page; |
| if (addrs) |
| addrs[pg_index] = addr; |
| |
| page++; |
| addr += PAGE_SIZE; |
| len -= PAGE_SIZE; |
| pg_index++; |
| } |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays); |
| /* helper function to cleanup a GEM/prime object */ |
| void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg) |
| { |
| struct dma_buf_attachment *attach; |
| struct dma_buf *dma_buf; |
| attach = obj->import_attach; |
| if (sg) |
| dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL); |
| dma_buf = attach->dmabuf; |
| dma_buf_detach(attach->dmabuf, attach); |
| /* remove the reference */ |
| dma_buf_put(dma_buf); |
| } |
| EXPORT_SYMBOL(drm_prime_gem_destroy); |
| |
| void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv) |
| { |
| INIT_LIST_HEAD(&prime_fpriv->head); |
| mutex_init(&prime_fpriv->lock); |
| } |
| EXPORT_SYMBOL(drm_prime_init_file_private); |
| |
| void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv) |
| { |
| /* by now drm_gem_release should've made sure the list is empty */ |
| WARN_ON(!list_empty(&prime_fpriv->head)); |
| } |
| EXPORT_SYMBOL(drm_prime_destroy_file_private); |
| |
| static 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; |
| |
| member = kmalloc(sizeof(*member), GFP_KERNEL); |
| if (!member) |
| return -ENOMEM; |
| |
| get_dma_buf(dma_buf); |
| member->dma_buf = dma_buf; |
| member->handle = handle; |
| list_add(&member->entry, &prime_fpriv->head); |
| return 0; |
| } |
| |
| int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf, uint32_t *handle) |
| { |
| struct drm_prime_member *member; |
| |
| list_for_each_entry(member, &prime_fpriv->head, entry) { |
| if (member->dma_buf == dma_buf) { |
| *handle = member->handle; |
| return 0; |
| } |
| } |
| return -ENOENT; |
| } |
| EXPORT_SYMBOL(drm_prime_lookup_buf_handle); |
| |
| void drm_prime_remove_buf_handle(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf) |
| { |
| struct drm_prime_member *member, *safe; |
| |
| mutex_lock(&prime_fpriv->lock); |
| list_for_each_entry_safe(member, safe, &prime_fpriv->head, entry) { |
| if (member->dma_buf == dma_buf) { |
| dma_buf_put(dma_buf); |
| list_del(&member->entry); |
| kfree(member); |
| } |
| } |
| mutex_unlock(&prime_fpriv->lock); |
| } |
| EXPORT_SYMBOL(drm_prime_remove_buf_handle); |