diff options
Diffstat (limited to 'drivers/gpu/drm/drm_prime.c')
| -rw-r--r-- | drivers/gpu/drm/drm_prime.c | 774 |
1 files changed, 774 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..7fec191b4 --- /dev/null +++ b/drivers/gpu/drm/drm_prime.c @@ -0,0 +1,774 @@ +/* + * 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> +#include <drm/drm_gem.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 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; +}; + +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; + + 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; +} + +static struct dma_buf *drm_prime_lookup_buf_by_handle(struct drm_prime_file_private *prime_fpriv, + uint32_t handle) +{ + struct drm_prime_member *member; + + list_for_each_entry(member, &prime_fpriv->head, entry) { + if (member->handle == handle) + return member->dma_buf; + } + + 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 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; +} + +static int drm_gem_map_attach(struct dma_buf *dma_buf, + struct device *target_dev, + struct dma_buf_attachment *attach) +{ + struct drm_prime_attachment *prime_attach; + struct drm_gem_object *obj = dma_buf->priv; + struct drm_device *dev = obj->dev; + + prime_attach = kzalloc(sizeof(*prime_attach), GFP_KERNEL); + if (!prime_attach) + return -ENOMEM; + + prime_attach->dir = DMA_NONE; + attach->priv = prime_attach; + + 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_prime_attachment *prime_attach = attach->priv; + struct drm_gem_object *obj = dma_buf->priv; + struct drm_device *dev = obj->dev; + struct sg_table *sgt; + + if (dev->driver->gem_prime_unpin) + dev->driver->gem_prime_unpin(obj); + + if (!prime_attach) + return; + + sgt = prime_attach->sgt; + if (sgt) { + if (prime_attach->dir != DMA_NONE) + dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, + prime_attach->dir); + sg_free_table(sgt); + } + + kfree(sgt); + kfree(prime_attach); + attach->priv = NULL; +} + +void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpriv, + struct dma_buf *dma_buf) +{ + struct drm_prime_member *member, *safe; + + 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); + } + } +} + +static 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); + + 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); + } else { + prime_attach->sgt = sgt; + prime_attach->dir = dir; + } + } + + return sgt; +} + +static 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 */ +} + +/** + * 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. + */ +void drm_gem_dmabuf_release(struct dma_buf *dma_buf) +{ + struct drm_gem_object *obj = dma_buf->priv; + + /* drop the reference on the export fd holds */ + drm_gem_object_unreference_unlocked(obj); +} +EXPORT_SYMBOL(drm_gem_dmabuf_release); + +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) +{ + 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); +} + +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 + */ + +/** + * 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 + * + * 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) +{ + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + + exp_info.ops = &drm_gem_prime_dmabuf_ops; + exp_info.size = obj->size; + exp_info.flags = flags; + exp_info.priv = obj; + + if (dev->driver->gem_prime_res_obj) + exp_info.resv = dev->driver->gem_prime_res_obj(obj); + + return dma_buf_export(&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; + } + + dmabuf = dev->driver->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); + /* Grab a new ref since the callers is now used by the dma-buf */ + drm_gem_object_reference(obj); + + 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(dev, 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_unreference_unlocked(obj); +out_unlock: + mutex_unlock(&file_priv->prime.lock); + + return ret; +} +EXPORT_SYMBOL(drm_gem_prime_handle_to_fd); + +/** + * 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) +{ + 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(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); + +/** + * 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); + obj = dev->driver->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); + } + + /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */ + ret = drm_gem_handle_create_tail(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_handle_delete(file_priv, *handle); +out_unlock: + mutex_unlock(&dev->object_name_lock); +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 - 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: array of page pointers to store the page array in + * @addrs: optional array to store the dma bus address of each page + * @max_pages: 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_pages) +{ + unsigned count; + struct scatterlist *sg; + struct page *page; + u32 len; + int pg_index; + dma_addr_t addr; + + pg_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(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); + +/** + * 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) +{ + INIT_LIST_HEAD(&prime_fpriv->head); + mutex_init(&prime_fpriv->lock); +} + +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)); +} |