diff options
Diffstat (limited to 'drivers/gpu/drm/drm_prime.c')
| -rw-r--r-- | drivers/gpu/drm/drm_prime.c | 1065 |
1 files changed, 1065 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c new file mode 100644 index 000000000..eb09e8604 --- /dev/null +++ b/drivers/gpu/drm/drm_prime.c @@ -0,0 +1,1065 @@ +/* + * 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 <linux/rbtree.h> +#include <linux/module.h> + +#include <drm/drm.h> +#include <drm/drm_drv.h> +#include <drm/drm_file.h> +#include <drm/drm_framebuffer.h> +#include <drm/drm_gem.h> +#include <drm/drm_prime.h> + +#include "drm_internal.h" + +MODULE_IMPORT_NS(DMA_BUF); + +/** + * DOC: overview and lifetime rules + * + * Similar to GEM global names, PRIME file descriptors are also used to share + * buffer objects across processes. They offer additional security: as file + * descriptors must be explicitly sent over UNIX domain sockets to be shared + * 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. + * + * Reference Counting for GEM Drivers + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * On the export the &dma_buf holds a reference to the exported buffer object, + * usually a &drm_gem_object. It takes this reference in the PRIME_HANDLE_TO_FD + * IOCTL, when it first calls &drm_gem_object_funcs.export + * and stores the exporting GEM object in the &dma_buf.priv field. This + * reference needs to be released when the final reference to the &dma_buf + * itself is dropped and its &dma_buf_ops.release function is called. For + * GEM-based drivers, the &dma_buf should be exported using + * drm_gem_dmabuf_export() and then released by drm_gem_dmabuf_release(). + * + * 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 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 + * retain a weak reference, which is cleaned up when the corresponding object is + * released. + * + * 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 underlying object from the + * dma-buf private. For GEM based drivers this is handled in + * drm_gem_prime_import() already. + */ + +struct drm_prime_member { + struct dma_buf *dma_buf; + uint32_t handle; + + struct rb_node dmabuf_rb; + struct rb_node handle_rb; +}; + +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; + struct rb_node **p, *rb; + + member = kmalloc(sizeof(*member), GFP_KERNEL); + if (!member) + return -ENOMEM; + + get_dma_buf(dma_buf); + member->dma_buf = dma_buf; + member->handle = handle; + + rb = NULL; + p = &prime_fpriv->dmabufs.rb_node; + while (*p) { + struct drm_prime_member *pos; + + rb = *p; + pos = rb_entry(rb, struct drm_prime_member, dmabuf_rb); + if (dma_buf > pos->dma_buf) + p = &rb->rb_right; + else + p = &rb->rb_left; + } + rb_link_node(&member->dmabuf_rb, rb, p); + rb_insert_color(&member->dmabuf_rb, &prime_fpriv->dmabufs); + + rb = NULL; + p = &prime_fpriv->handles.rb_node; + while (*p) { + struct drm_prime_member *pos; + + rb = *p; + pos = rb_entry(rb, struct drm_prime_member, handle_rb); + if (handle > pos->handle) + p = &rb->rb_right; + else + p = &rb->rb_left; + } + rb_link_node(&member->handle_rb, rb, p); + rb_insert_color(&member->handle_rb, &prime_fpriv->handles); + + return 0; +} + +static struct dma_buf *drm_prime_lookup_buf_by_handle(struct drm_prime_file_private *prime_fpriv, + uint32_t handle) +{ + struct rb_node *rb; + + rb = prime_fpriv->handles.rb_node; + while (rb) { + struct drm_prime_member *member; + + member = rb_entry(rb, struct drm_prime_member, handle_rb); + if (member->handle == handle) + return member->dma_buf; + else if (member->handle < handle) + rb = rb->rb_right; + else + rb = rb->rb_left; + } + + return NULL; +} + +static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpriv, + struct dma_buf *dma_buf, + uint32_t *handle) +{ + struct rb_node *rb; + + rb = prime_fpriv->dmabufs.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) { + *handle = member->handle; + return 0; + } else if (member->dma_buf < dma_buf) { + rb = rb->rb_right; + } else { + rb = rb->rb_left; + } + } + + return -ENOENT; +} + +void drm_prime_remove_buf_handle(struct drm_prime_file_private *prime_fpriv, + uint32_t handle) +{ + struct rb_node *rb; + + mutex_lock(&prime_fpriv->lock); + + rb = prime_fpriv->handles.rb_node; + while (rb) { + struct drm_prime_member *member; + + 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(member->dma_buf); + kfree(member); + break; + } else if (member->handle < handle) { + rb = rb->rb_right; + } else { + rb = rb->rb_left; + } + } + + mutex_unlock(&prime_fpriv->lock); +} + +void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv) +{ + mutex_init(&prime_fpriv->lock); + prime_fpriv->dmabufs = RB_ROOT; + prime_fpriv->handles = RB_ROOT; +} + +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(!RB_EMPTY_ROOT(&prime_fpriv->dmabufs)); +} + +/** + * drm_gem_dmabuf_export - &dma_buf export implementation for GEM + * @dev: parent device for the exported dmabuf + * @exp_info: the export information used by dma_buf_export() + * + * This wraps dma_buf_export() for use by generic GEM drivers that are using + * drm_gem_dmabuf_release(). In addition to calling dma_buf_export(), we take + * a reference to the &drm_device and the exported &drm_gem_object (stored in + * &dma_buf_export_info.priv) which is released by drm_gem_dmabuf_release(). + * + * Returns the new dmabuf. + */ +struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev, + struct dma_buf_export_info *exp_info) +{ + struct drm_gem_object *obj = exp_info->priv; + struct dma_buf *dma_buf; + + dma_buf = dma_buf_export(exp_info); + if (IS_ERR(dma_buf)) + return dma_buf; + + drm_dev_get(dev); + drm_gem_object_get(obj); + dma_buf->file->f_mapping = obj->dev->anon_inode->i_mapping; + + return dma_buf; +} +EXPORT_SYMBOL(drm_gem_dmabuf_export); + +/** + * drm_gem_dmabuf_release - &dma_buf release implementation for GEM + * @dma_buf: buffer to be released + * + * Generic release function for dma_bufs exported as PRIME buffers. GEM drivers + * must use this in their &dma_buf_ops structure as the release callback. + * drm_gem_dmabuf_release() should be used in conjunction with + * drm_gem_dmabuf_export(). + */ +void drm_gem_dmabuf_release(struct dma_buf *dma_buf) +{ + struct drm_gem_object *obj = dma_buf->priv; + struct drm_device *dev = obj->dev; + + /* drop the reference on the export fd holds */ + drm_gem_object_put(obj); + + drm_dev_put(dev); +} +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 + * @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 + * + * This is the PRIME import function which must be used mandatorily by GEM + * drivers to ensure correct lifetime management of the underlying GEM object. + * The actual importing of GEM object from the dma-buf is done through the + * &drm_driver.gem_prime_import driver callback. + * + * Returns 0 on success or a negative error code on failure. + */ +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 == 0) + goto out_put; + + /* never seen this one, need to import */ + mutex_lock(&dev->object_name_lock); + if (dev->driver->gem_prime_import) + obj = dev->driver->gem_prime_import(dev, dma_buf); + else + obj = drm_gem_prime_import(dev, dma_buf); + if (IS_ERR(obj)) { + ret = PTR_ERR(obj); + goto out_unlock; + } + + if (obj->dma_buf) { + WARN_ON(obj->dma_buf != dma_buf); + } else { + obj->dma_buf = dma_buf; + get_dma_buf(dma_buf); + } + + /* _handle_create_tail unconditionally unlocks dev->object_name_lock. */ + ret = drm_gem_handle_create_tail(file_priv, obj, handle); + drm_gem_object_put(obj); + if (ret) + goto out_put; + + ret = drm_prime_add_buf_handle(&file_priv->prime, + dma_buf, *handle); + mutex_unlock(&file_priv->prime.lock); + if (ret) + goto fail; + + 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_handle_delete(file_priv, *handle); + dma_buf_put(dma_buf); + return ret; + +out_unlock: + mutex_unlock(&dev->object_name_lock); +out_put: + mutex_unlock(&file_priv->prime.lock); + dma_buf_put(dma_buf); + return ret; +} +EXPORT_SYMBOL(drm_gem_prime_fd_to_handle); + +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 (!dev->driver->prime_fd_to_handle) + return -ENOSYS; + + return dev->driver->prime_fd_to_handle(dev, file_priv, + args->fd, &args->handle); +} + +static struct dma_buf *export_and_register_object(struct drm_device *dev, + struct drm_gem_object *obj, + uint32_t flags) +{ + struct dma_buf *dmabuf; + + /* prevent races with concurrent gem_close. */ + if (obj->handle_count == 0) { + dmabuf = ERR_PTR(-ENOENT); + return dmabuf; + } + + if (obj->funcs && obj->funcs->export) + dmabuf = obj->funcs->export(obj, flags); + else + dmabuf = drm_gem_prime_export(obj, flags); + if (IS_ERR(dmabuf)) { + /* normally the created dma-buf takes ownership of the ref, + * but if that fails then drop the ref + */ + return dmabuf; + } + + /* + * Note that callers do not need to clean up the export cache + * since the check for obj->handle_count guarantees that someone + * will clean it up. + */ + obj->dma_buf = dmabuf; + get_dma_buf(obj->dma_buf); + + return dmabuf; +} + +/** + * 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 drm_gem_object *obj; + int ret = 0; + struct dma_buf *dmabuf; + + mutex_lock(&file_priv->prime.lock); + obj = drm_gem_object_lookup(file_priv, handle); + if (!obj) { + ret = -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; + } + + mutex_lock(&dev->object_name_lock); + /* re-export the original imported object */ + if (obj->import_attach) { + dmabuf = obj->import_attach->dmabuf; + get_dma_buf(dmabuf); + goto out_have_obj; + } + + if (obj->dma_buf) { + get_dma_buf(obj->dma_buf); + dmabuf = obj->dma_buf; + goto out_have_obj; + } + + dmabuf = export_and_register_object(dev, obj, flags); + if (IS_ERR(dmabuf)) { + /* 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; + } + +out_have_obj: + /* + * If we've exported this buffer then cheat and add it to the import list + * so we get the correct handle back. We must do this under the + * protection of dev->object_name_lock to ensure that a racing gem close + * ioctl doesn't miss to remove this buffer handle from the cache. + */ + 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; + } + + goto out; + +fail_put_dmabuf: + dma_buf_put(dmabuf); +out: + drm_gem_object_put(obj); +out_unlock: + mutex_unlock(&file_priv->prime.lock); + + return ret; +} +EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); + +int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_priv) +{ + 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); +} + +/** + * DOC: PRIME Helpers + * + * Drivers can implement &drm_gem_object_funcs.export and + * &drm_driver.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 some lower-level helpers, which are + * again exported for drivers to use individually: + * + * Exporting buffers + * ~~~~~~~~~~~~~~~~~ + * + * 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. + * + * For kernel-internal access there's drm_gem_dmabuf_vmap() and + * drm_gem_dmabuf_vunmap(). Userspace mmap support is provided by + * drm_gem_dmabuf_mmap(). + * + * Note that these export helpers can only be used if the underlying backing + * storage is fully coherent and either permanently pinned, or it is safe to pin + * it indefinitely. + * + * FIXME: The underlying helper functions are named rather inconsistently. + * + * Importing buffers + * ~~~~~~~~~~~~~~~~~ + * + * Importing dma-bufs using drm_gem_prime_import() relies on + * &drm_driver.gem_prime_import_sg_table. + * + * Note that similarly to the export helpers this permanently pins the + * underlying backing storage. Which is ok for scanout, but is not the best + * option for sharing lots of buffers for rendering. + */ + +/** + * drm_gem_map_attach - dma_buf attach implementation for GEM + * @dma_buf: buffer to attach device to + * @attach: buffer attachment data + * + * Calls &drm_gem_object_funcs.pin for device specific handling. This can be + * used as the &dma_buf_ops.attach callback. Must be used together with + * drm_gem_map_detach(). + * + * Returns 0 on success, negative error code on failure. + */ +int drm_gem_map_attach(struct dma_buf *dma_buf, + struct dma_buf_attachment *attach) +{ + struct drm_gem_object *obj = dma_buf->priv; + + return drm_gem_pin(obj); +} +EXPORT_SYMBOL(drm_gem_map_attach); + +/** + * drm_gem_map_detach - dma_buf detach implementation for GEM + * @dma_buf: buffer to detach from + * @attach: attachment to be detached + * + * Calls &drm_gem_object_funcs.pin for device specific handling. Cleans up + * &dma_buf_attachment from drm_gem_map_attach(). This can be used as the + * &dma_buf_ops.detach callback. + */ +void drm_gem_map_detach(struct dma_buf *dma_buf, + struct dma_buf_attachment *attach) +{ + struct drm_gem_object *obj = dma_buf->priv; + + drm_gem_unpin(obj); +} +EXPORT_SYMBOL(drm_gem_map_detach); + +/** + * drm_gem_map_dma_buf - map_dma_buf implementation for GEM + * @attach: attachment whose scatterlist is to be returned + * @dir: direction of DMA transfer + * + * Calls &drm_gem_object_funcs.get_sg_table and then maps the scatterlist. This + * can be used as the &dma_buf_ops.map_dma_buf callback. Should be used together + * with drm_gem_unmap_dma_buf(). + * + * Returns:sg_table containing the scatterlist to be returned; returns ERR_PTR + * on error. May return -EINTR if it is interrupted by a signal. + */ +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; + int ret; + + if (WARN_ON(dir == DMA_NONE)) + return ERR_PTR(-EINVAL); + + if (WARN_ON(!obj->funcs->get_sg_table)) + return ERR_PTR(-ENOSYS); + + sgt = obj->funcs->get_sg_table(obj); + if (IS_ERR(sgt)) + return sgt; + + ret = dma_map_sgtable(attach->dev, sgt, dir, + DMA_ATTR_SKIP_CPU_SYNC); + if (ret) { + sg_free_table(sgt); + kfree(sgt); + sgt = ERR_PTR(ret); + } + + return sgt; +} +EXPORT_SYMBOL(drm_gem_map_dma_buf); + +/** + * drm_gem_unmap_dma_buf - unmap_dma_buf implementation for GEM + * @attach: attachment to unmap buffer from + * @sgt: scatterlist info of the buffer to unmap + * @dir: direction of DMA transfer + * + * This can be used as the &dma_buf_ops.unmap_dma_buf callback. + */ +void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach, + struct sg_table *sgt, + enum dma_data_direction dir) +{ + if (!sgt) + return; + + dma_unmap_sgtable(attach->dev, sgt, dir, DMA_ATTR_SKIP_CPU_SYNC); + sg_free_table(sgt); + kfree(sgt); +} +EXPORT_SYMBOL(drm_gem_unmap_dma_buf); + +/** + * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM + * @dma_buf: buffer to be mapped + * @map: the virtual address of the buffer + * + * Sets up a kernel virtual mapping. This can be used as the &dma_buf_ops.vmap + * callback. Calls into &drm_gem_object_funcs.vmap for device specific handling. + * The kernel virtual address is returned in map. + * + * Returns 0 on success or a negative errno code otherwise. + */ +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); +} +EXPORT_SYMBOL(drm_gem_dmabuf_vmap); + +/** + * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation for GEM + * @dma_buf: buffer to be unmapped + * @map: the virtual address of the buffer + * + * 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 iosys_map *map) +{ + struct drm_gem_object *obj = dma_buf->priv; + + drm_gem_vunmap(obj, map); +} +EXPORT_SYMBOL(drm_gem_dmabuf_vunmap); + +/** + * drm_gem_prime_mmap - PRIME mmap function for GEM drivers + * @obj: GEM object + * @vma: Virtual address range + * + * This function sets up a userspace mapping for PRIME exported buffers using + * 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) +{ + struct drm_file *priv; + struct file *fil; + int ret; + + /* Add the fake offset */ + vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); + + 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) { + drm_gem_object_put(obj); + return ret; + } + vma->vm_private_data = obj; + return 0; + } + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + fil = kzalloc(sizeof(*fil), GFP_KERNEL); + if (!priv || !fil) { + ret = -ENOMEM; + goto out; + } + + /* Used by drm_gem_mmap() to lookup the GEM object */ + priv->minor = obj->dev->primary; + fil->private_data = priv; + + ret = drm_vma_node_allow(&obj->vma_node, priv); + if (ret) + goto out; + + ret = obj->dev->driver->fops->mmap(fil, vma); + + drm_vma_node_revoke(&obj->vma_node, priv); +out: + kfree(priv); + kfree(fil); + + return ret; +} +EXPORT_SYMBOL(drm_gem_prime_mmap); + +/** + * drm_gem_dmabuf_mmap - dma_buf mmap implementation for GEM + * @dma_buf: buffer to be mapped + * @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. + * + * 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); +} +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, + .unmap_dma_buf = drm_gem_unmap_dma_buf, + .release = drm_gem_dmabuf_release, + .mmap = drm_gem_dmabuf_mmap, + .vmap = drm_gem_dmabuf_vmap, + .vunmap = drm_gem_dmabuf_vunmap, +}; + +/** + * drm_prime_pages_to_sg - converts a page array into an sg list + * @dev: DRM device + * @pages: pointer to the array of page pointers to convert + * @nr_pages: length of the page vector + * + * 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 for use with dma_buf itself. + * + * This is useful for implementing &drm_gem_object_funcs.get_sg_table. + */ +struct sg_table *drm_prime_pages_to_sg(struct drm_device *dev, + struct page **pages, unsigned int nr_pages) +{ + struct sg_table *sg; + size_t max_segment = 0; + int err; + + sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL); + if (!sg) + return ERR_PTR(-ENOMEM); + + if (dev) + max_segment = dma_max_mapping_size(dev->dev); + if (max_segment == 0) + max_segment = UINT_MAX; + err = sg_alloc_table_from_pages_segment(sg, pages, nr_pages, 0, + nr_pages << PAGE_SHIFT, + max_segment, GFP_KERNEL); + if (err) { + kfree(sg); + sg = ERR_PTR(err); + } + return sg; +} +EXPORT_SYMBOL(drm_prime_pages_to_sg); + +/** + * drm_prime_get_contiguous_size - returns the contiguous size of the buffer + * @sgt: sg_table describing the buffer to check + * + * This helper calculates the contiguous size in the DMA address space + * of the buffer described by the provided sg_table. + * + * This is useful for implementing + * &drm_gem_object_funcs.gem_prime_import_sg_table. + */ +unsigned long drm_prime_get_contiguous_size(struct sg_table *sgt) +{ + dma_addr_t expected = sg_dma_address(sgt->sgl); + struct scatterlist *sg; + unsigned long size = 0; + int i; + + for_each_sgtable_dma_sg(sgt, sg, i) { + unsigned int len = sg_dma_len(sg); + + if (!len) + break; + if (sg_dma_address(sg) != expected) + break; + expected += len; + size += len; + } + return size; +} +EXPORT_SYMBOL(drm_prime_get_contiguous_size); + +/** + * drm_gem_prime_export - helper library implementation of the export callback + * @obj: GEM object to export + * @flags: flags like DRM_CLOEXEC and DRM_RDWR + * + * This is the implementation of the &drm_gem_object_funcs.export functions for GEM drivers + * using the PRIME helpers. It is used as the default in + * drm_gem_prime_handle_to_fd(). + */ +struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj, + int flags) +{ + struct drm_device *dev = obj->dev; + struct dma_buf_export_info exp_info = { + .exp_name = KBUILD_MODNAME, /* white lie for debug */ + .owner = dev->driver->fops->owner, + .ops = &drm_gem_prime_dmabuf_ops, + .size = obj->size, + .flags = flags, + .priv = obj, + .resv = obj->resv, + }; + + return drm_gem_dmabuf_export(dev, &exp_info); +} +EXPORT_SYMBOL(drm_gem_prime_export); + +/** + * drm_gem_prime_import_dev - core implementation of the import callback + * @dev: drm_device to import into + * @dma_buf: dma-buf object to import + * @attach_dev: struct device to dma_buf attach + * + * This is the core of drm_gem_prime_import(). It's designed to be called by + * drivers who want to use a different device structure than &drm_device.dev for + * attaching via dma_buf. This function calls + * &drm_driver.gem_prime_import_sg_table internally. + * + * Drivers must arrange to call drm_prime_gem_destroy() from their + * &drm_gem_object_funcs.free hook when using this function. + */ +struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev, + struct dma_buf *dma_buf, + struct device *attach_dev) +{ + struct dma_buf_attachment *attach; + struct sg_table *sgt; + struct drm_gem_object *obj; + int ret; + + 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_get(obj); + return obj; + } + } + + if (!dev->driver->gem_prime_import_sg_table) + return ERR_PTR(-EINVAL); + + attach = dma_buf_attach(dma_buf, attach_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(sgt)) { + ret = PTR_ERR(sgt); + goto fail_detach; + } + + obj = dev->driver->gem_prime_import_sg_table(dev, attach, sgt); + if (IS_ERR(obj)) { + ret = PTR_ERR(obj); + goto fail_unmap; + } + + obj->import_attach = attach; + obj->resv = dma_buf->resv; + + 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_dev); + +/** + * drm_gem_prime_import - helper library implementation of the import callback + * @dev: drm_device to import into + * @dma_buf: dma-buf object to import + * + * This is the implementation of the gem_prime_import functions for GEM drivers + * using the PRIME helpers. Drivers can use this as their + * &drm_driver.gem_prime_import implementation. It is used as the default + * implementation in drm_gem_prime_fd_to_handle(). + * + * Drivers must arrange to call drm_prime_gem_destroy() from their + * &drm_gem_object_funcs.free hook when using this function. + */ +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); +} +EXPORT_SYMBOL(drm_gem_prime_import); + +/** + * drm_prime_sg_to_page_array - convert an sg table into a page array + * @sgt: scatter-gather table to convert + * @pages: array of page pointers to store the pages in + * @max_entries: size of the passed-in array + * + * Exports an sg table into an array of pages. + * + * This function is deprecated and strongly discouraged to be used. + * The page array is only useful for page faults and those can corrupt fields + * in the struct page if they are not handled by the exporting driver. + */ +int __deprecated drm_prime_sg_to_page_array(struct sg_table *sgt, + struct page **pages, + int max_entries) +{ + struct sg_page_iter page_iter; + struct page **p = pages; + + for_each_sgtable_page(sgt, &page_iter, 0) { + if (WARN_ON(p - pages >= max_entries)) + return -1; + *p++ = sg_page_iter_page(&page_iter); + } + return 0; +} +EXPORT_SYMBOL(drm_prime_sg_to_page_array); + +/** + * drm_prime_sg_to_dma_addr_array - convert an sg table into a dma addr array + * @sgt: scatter-gather table to convert + * @addrs: array to store the dma bus address of each page + * @max_entries: size of both the passed-in arrays + * + * Exports an sg table into an array of addresses. + * + * Drivers should use this in their &drm_driver.gem_prime_import_sg_table + * implementation. + */ +int drm_prime_sg_to_dma_addr_array(struct sg_table *sgt, dma_addr_t *addrs, + int max_entries) +{ + struct sg_dma_page_iter dma_iter; + dma_addr_t *a = addrs; + + for_each_sgtable_dma_page(sgt, &dma_iter, 0) { + if (WARN_ON(a - addrs >= max_entries)) + return -1; + *a++ = sg_page_iter_dma_address(&dma_iter); + } + return 0; +} +EXPORT_SYMBOL(drm_prime_sg_to_dma_addr_array); + +/** + * drm_prime_gem_destroy - helper to clean up a PRIME-imported GEM object + * @obj: GEM object which was created from a dma-buf + * @sg: the sg-table which was pinned at import time + * + * This is the cleanup functions which GEM drivers need to call when they use + * drm_gem_prime_import() or drm_gem_prime_import_dev() to import dma-bufs. + */ +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); |