mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Christian König](/assets/img/avatar_default.png)
Mapping the imported pages of a DMA-buf into an userspace process doesn't work as expected. But we have reoccurring requests on this approach, so split the functions for this and document that dma_buf_mmap() needs to be used instead. v2: split it into two functions v3: rebased on latest changes v4: update commit message a bit Signed-off-by: Christian König <christian.koenig@amd.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/403838/
1055 lines
30 KiB
C
1055 lines
30 KiB
C
/*
|
|
* 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.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"
|
|
|
|
/**
|
|
* 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 uniqe 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_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;
|
|
}
|
|
}
|
|
}
|
|
|
|
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.
|
|
*
|
|
* Exporting 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 dma_buf_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 dma_buf_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) {
|
|
ret = obj->funcs->mmap(obj, vma);
|
|
if (ret)
|
|
return ret;
|
|
vma->vm_private_data = obj;
|
|
drm_gem_object_get(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;
|
|
struct scatterlist *sge;
|
|
size_t max_segment = 0;
|
|
|
|
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;
|
|
sge = __sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
|
|
nr_pages << PAGE_SHIFT,
|
|
max_segment,
|
|
NULL, 0, GFP_KERNEL);
|
|
if (IS_ERR(sge)) {
|
|
kfree(sg);
|
|
sg = ERR_CAST(sge);
|
|
}
|
|
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 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);
|