/* * 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 <drm/drm_prime.h> #include <drm/drm_gem.h> #include <drm/drmP.h> #include "drm_internal.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 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(). * * 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. * * When all the references to the &dma_buf are dropped, i.e. when * userspace has closed both handles to the imported GEM object (through the * FD_TO_HANDLE IOCTL) and closed the file descriptor of the exported * (through the HANDLE_TO_FD IOCTL) dma_buf, and all kernel-internal references * are also gone, then the dma_buf gets destroyed. This can also happen as a * part of the clean up procedure in the drm_release() function if userspace * fails to properly clean up. Note that both the kernel and userspace (by * keeeping the PRIME file descriptors open) can hold references onto a * &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. * * GEM struct &dma_buf_ops symbols are now exported. They can be resued by * drivers which implement GEM interface. */ struct drm_prime_member { struct dma_buf *dma_buf; uint32_t handle; struct rb_node dmabuf_rb; struct rb_node handle_rb; }; struct drm_prime_attachment { struct sg_table *sgt; enum dma_data_direction dir; }; 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; } /** * drm_gem_map_attach - dma_buf attach implementation for GEM * @dma_buf: buffer to attach device to * @attach: buffer attachment data * * Allocates &drm_prime_attachment and calls &drm_driver.gem_prime_pin for * device specific attachment. This can be used as the &dma_buf_ops.attach * callback. * * 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_prime_attachment *prime_attach; struct drm_gem_object *obj = dma_buf->priv; prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL); if (!prime_attach) return -ENOMEM; prime_attach->dir = DMA_NONE; attach->priv = prime_attach; 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 * * Cleans up &dma_buf_attachment. 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_prime_attachment *prime_attach = attach->priv; struct drm_gem_object *obj = dma_buf->priv; if (prime_attach) { struct sg_table *sgt = prime_attach->sgt; if (sgt) { if (prime_attach->dir != DMA_NONE) dma_unmap_sg_attrs(attach->dev, sgt->sgl, sgt->nents, prime_attach->dir, DMA_ATTR_SKIP_CPU_SYNC); sg_free_table(sgt); } kfree(sgt); kfree(prime_attach); attach->priv = NULL; } drm_gem_unpin(obj); } EXPORT_SYMBOL(drm_gem_map_detach); void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpriv, struct dma_buf *dma_buf) { 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) { rb_erase(&member->handle_rb, &prime_fpriv->handles); rb_erase(&member->dmabuf_rb, &prime_fpriv->dmabufs); dma_buf_put(dma_buf); kfree(member); return; } else if (member->dma_buf < dma_buf) { rb = rb->rb_right; } else { rb = rb->rb_left; } } } /** * 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_driver.gem_prime_get_sg_table and then maps the scatterlist. This * can be used as the &dma_buf_ops.map_dma_buf callback. * * 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_prime_attachment *prime_attach = attach->priv; struct drm_gem_object *obj = attach->dmabuf->priv; struct sg_table *sgt; if (WARN_ON(dir == DMA_NONE || !prime_attach)) return ERR_PTR(-EINVAL); /* return the cached mapping when possible */ if (prime_attach->dir == dir) return prime_attach->sgt; /* * two mappings with different directions for the same attachment are * not allowed */ if (WARN_ON(prime_attach->dir != DMA_NONE)) return ERR_PTR(-EBUSY); if (obj->funcs) sgt = obj->funcs->get_sg_table(obj); else sgt = obj->dev->driver->gem_prime_get_sg_table(obj); if (!IS_ERR(sgt)) { if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir, DMA_ATTR_SKIP_CPU_SYNC)) { sg_free_table(sgt); kfree(sgt); sgt = ERR_PTR(-ENOMEM); } else { prime_attach->sgt = sgt; prime_attach->dir = dir; } } 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 * * Not implemented. The unmap is done at drm_gem_map_detach(). 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) { /* nothing to be done here */ } EXPORT_SYMBOL(drm_gem_unmap_dma_buf); /** * 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 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(exp_info->priv); 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_unlocked(obj); drm_dev_put(dev); } EXPORT_SYMBOL(drm_gem_dmabuf_release); /** * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM * @dma_buf: buffer to be mapped * * Sets up a kernel virtual mapping. This can be used as the &dma_buf_ops.vmap * callback. * * Returns the kernel virtual address. */ void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf) { struct drm_gem_object *obj = dma_buf->priv; void *vaddr; vaddr = drm_gem_vmap(obj); if (IS_ERR(vaddr)) vaddr = NULL; return vaddr; } EXPORT_SYMBOL(drm_gem_dmabuf_vmap); /** * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation for GEM * @dma_buf: buffer to be unmapped * @vaddr: the virtual address of the buffer * * Releases a kernel virtual mapping. This can be used as the * &dma_buf_ops.vunmap callback. */ void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) { struct drm_gem_object *obj = dma_buf->priv; drm_gem_vunmap(obj, vaddr); } EXPORT_SYMBOL(drm_gem_dmabuf_vunmap); /** * 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. * * 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 = { .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, }; /** * 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 * six 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 * * @gem_prime_mmap (optional): mmap 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 */ /** * drm_gem_prime_export - helper library implementation of the export callback * @dev: drm_device to export from * @obj: GEM object to export * @flags: flags like DRM_CLOEXEC and DRM_RDWR * * This is the implementation of the gem_prime_export functions for GEM drivers * using the PRIME helpers. */ struct dma_buf *drm_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags) { 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, }; if (dev->driver->gem_prime_res_obj) exp_info.resv = dev->driver->gem_prime_res_obj(obj); return drm_gem_dmabuf_export(dev, &exp_info); } EXPORT_SYMBOL(drm_gem_prime_export); 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 if (dev->driver->gem_prime_export) dmabuf = dev->driver->gem_prime_export(dev, obj, flags); else dmabuf = drm_gem_prime_export(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 */ 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 * gem_prime_export driver 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_unlocked(obj); out_unlock: mutex_unlock(&file_priv->prime.lock); return ret; } EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); /** * 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; 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; vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); 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_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 dev->dev for * attaching via dma_buf. */ 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; 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. */ 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_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 * gem_import_export driver callback. */ 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_unlocked(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_handle_to_fd_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 -EOPNOTSUPP; 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); } 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 -EOPNOTSUPP; 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 - converts a page array into an sg list * @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. */ struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned 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); /** * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array * @sgt: scatter-gather table to convert * @pages: optional array of page pointers to store the page array in * @addrs: optional 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 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_entries) { unsigned count; struct scatterlist *sg; struct page *page; u32 len, index; dma_addr_t addr; index = 0; for_each_sg(sgt->sgl, sg, sgt->nents, count) { len = sg->length; page = sg_page(sg); addr = sg_dma_address(sg); while (len > 0) { if (WARN_ON(index >= max_entries)) return -1; if (pages) pages[index] = page; if (addrs) addrs[index] = addr; page++; addr += PAGE_SIZE; len -= PAGE_SIZE; index++; } } return 0; } EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays); /** * 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 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); 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)); }