linux-stable/drivers/gpu/drm/drm_prime.c
Gerd Hoffmann b3fac52c51 drm: share address space for dma bufs
Use the shared address space of the drm device (see drm_open() in
drm_file.c) for dma-bufs too.  That removes a difference betweem drm
device mmap vmas and dma-buf mmap vmas and fixes corner cases like
dropping ptes (using madvise(DONTNEED) for example) not working
properly.

Also remove amdgpu driver's private dmabuf update.  It is not needed
any more now that we are doing this for everybody.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20191127092523.5620-3-kraxel@redhat.com
2019-12-06 11:18:11 +01:00

1012 lines
29 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_unlocked(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_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_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 if (dev->driver->gem_prime_export)
dmabuf = dev->driver->gem_prime_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_driver.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);
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;
if (WARN_ON(dir == DMA_NONE))
return ERR_PTR(-EINVAL);
if (obj->funcs)
sgt = obj->funcs->get_sg_table(obj);
else
sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
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);
}
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_sg_attrs(attach->dev, sgt->sgl, sgt->nents, 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
*
* 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.
*
* Returns the kernel virtual address or NULL on failure.
*/
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. Calls into &drm_gem_object_funcs.vunmap for device specific handling.
*/
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_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
* @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 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_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_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.
*
* Drivers can use this in their &drm_driver.gem_prime_import_sg_table
* implementation.
*/
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() 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);