--- /dev/null
+/*
+ * 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));
+}
Code Review / kvmfornfv.git / blobdiff