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1061 lines
30 KiB
1061 lines
30 KiB
/* |
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* Copyright © 2012 Red Hat |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a |
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* copy of this software and associated documentation files (the "Software"), |
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* to deal in the Software without restriction, including without limitation |
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* the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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* and/or sell copies of the Software, and to permit persons to whom the |
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* Software is furnished to do so, subject to the following conditions: |
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* |
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* The above copyright notice and this permission notice (including the next |
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* paragraph) shall be included in all copies or substantial portions of the |
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* Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
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* IN THE SOFTWARE. |
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* |
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* Authors: |
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* Dave Airlie <[email protected]> |
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* Rob Clark <[email protected]> |
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* |
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*/ |
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|
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#include <linux/export.h> |
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#include <linux/dma-buf.h> |
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#include <linux/rbtree.h> |
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#include <linux/module.h> |
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|
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#include <drm/drm.h> |
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#include <drm/drm_drv.h> |
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#include <drm/drm_file.h> |
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#include <drm/drm_framebuffer.h> |
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#include <drm/drm_gem.h> |
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#include <drm/drm_prime.h> |
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|
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#include "drm_internal.h" |
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|
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MODULE_IMPORT_NS(DMA_BUF); |
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|
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/** |
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* DOC: overview and lifetime rules |
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* |
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* Similar to GEM global names, PRIME file descriptors are also used to share |
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* buffer objects across processes. They offer additional security: as file |
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* descriptors must be explicitly sent over UNIX domain sockets to be shared |
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* between applications, they can't be guessed like the globally unique GEM |
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* names. |
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* |
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* Drivers that support the PRIME API implement the |
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* &drm_driver.prime_handle_to_fd and &drm_driver.prime_fd_to_handle operations. |
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* GEM based drivers must use drm_gem_prime_handle_to_fd() and |
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* drm_gem_prime_fd_to_handle() to implement these. For GEM based drivers the |
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* actual driver interfaces is provided through the &drm_gem_object_funcs.export |
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* and &drm_driver.gem_prime_import hooks. |
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* |
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* &dma_buf_ops implementations for GEM drivers are all individually exported |
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* for drivers which need to overwrite or reimplement some of them. |
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* |
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* Reference Counting for GEM Drivers |
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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* |
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* On the export the &dma_buf holds a reference to the exported buffer object, |
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* usually a &drm_gem_object. It takes this reference in the PRIME_HANDLE_TO_FD |
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* IOCTL, when it first calls &drm_gem_object_funcs.export |
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* and stores the exporting GEM object in the &dma_buf.priv field. This |
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* reference needs to be released when the final reference to the &dma_buf |
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* itself is dropped and its &dma_buf_ops.release function is called. For |
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* GEM-based drivers, the &dma_buf should be exported using |
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* drm_gem_dmabuf_export() and then released by drm_gem_dmabuf_release(). |
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* |
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* Thus the chain of references always flows in one direction, avoiding loops: |
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* importing GEM object -> dma-buf -> exported GEM bo. A further complication |
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* are the lookup caches for import and export. These are required to guarantee |
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* that any given object will always have only one unique userspace handle. This |
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* is required to allow userspace to detect duplicated imports, since some GEM |
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* drivers do fail command submissions if a given buffer object is listed more |
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* than once. These import and export caches in &drm_prime_file_private only |
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* retain a weak reference, which is cleaned up when the corresponding object is |
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* released. |
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* |
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* Self-importing: If userspace is using PRIME as a replacement for flink then |
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* it will get a fd->handle request for a GEM object that it created. Drivers |
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* should detect this situation and return back the underlying object from the |
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* dma-buf private. For GEM based drivers this is handled in |
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* drm_gem_prime_import() already. |
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*/ |
|
|
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struct drm_prime_member { |
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struct dma_buf *dma_buf; |
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uint32_t handle; |
|
|
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struct rb_node dmabuf_rb; |
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struct rb_node handle_rb; |
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}; |
|
|
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static int drm_prime_add_buf_handle(struct drm_prime_file_private *prime_fpriv, |
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struct dma_buf *dma_buf, uint32_t handle) |
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{ |
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struct drm_prime_member *member; |
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struct rb_node **p, *rb; |
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|
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member = kmalloc(sizeof(*member), GFP_KERNEL); |
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if (!member) |
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return -ENOMEM; |
|
|
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get_dma_buf(dma_buf); |
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member->dma_buf = dma_buf; |
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member->handle = handle; |
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|
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rb = NULL; |
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p = &prime_fpriv->dmabufs.rb_node; |
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while (*p) { |
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struct drm_prime_member *pos; |
|
|
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rb = *p; |
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pos = rb_entry(rb, struct drm_prime_member, dmabuf_rb); |
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if (dma_buf > pos->dma_buf) |
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p = &rb->rb_right; |
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else |
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p = &rb->rb_left; |
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} |
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rb_link_node(&member->dmabuf_rb, rb, p); |
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rb_insert_color(&member->dmabuf_rb, &prime_fpriv->dmabufs); |
|
|
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rb = NULL; |
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p = &prime_fpriv->handles.rb_node; |
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while (*p) { |
|
struct drm_prime_member *pos; |
|
|
|
rb = *p; |
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pos = rb_entry(rb, struct drm_prime_member, handle_rb); |
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if (handle > pos->handle) |
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p = &rb->rb_right; |
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else |
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p = &rb->rb_left; |
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} |
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rb_link_node(&member->handle_rb, rb, p); |
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rb_insert_color(&member->handle_rb, &prime_fpriv->handles); |
|
|
|
return 0; |
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} |
|
|
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static struct dma_buf *drm_prime_lookup_buf_by_handle(struct drm_prime_file_private *prime_fpriv, |
|
uint32_t handle) |
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{ |
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struct rb_node *rb; |
|
|
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rb = prime_fpriv->handles.rb_node; |
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while (rb) { |
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struct drm_prime_member *member; |
|
|
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member = rb_entry(rb, struct drm_prime_member, handle_rb); |
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if (member->handle == handle) |
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return member->dma_buf; |
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else if (member->handle < handle) |
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rb = rb->rb_right; |
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else |
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rb = rb->rb_left; |
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} |
|
|
|
return NULL; |
|
} |
|
|
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static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpriv, |
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struct dma_buf *dma_buf, |
|
uint32_t *handle) |
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{ |
|
struct rb_node *rb; |
|
|
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rb = prime_fpriv->dmabufs.rb_node; |
|
while (rb) { |
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struct drm_prime_member *member; |
|
|
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member = rb_entry(rb, struct drm_prime_member, dmabuf_rb); |
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if (member->dma_buf == dma_buf) { |
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*handle = member->handle; |
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return 0; |
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} else if (member->dma_buf < dma_buf) { |
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rb = rb->rb_right; |
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} else { |
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rb = rb->rb_left; |
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} |
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} |
|
|
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return -ENOENT; |
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} |
|
|
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void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpriv, |
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struct dma_buf *dma_buf) |
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{ |
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struct rb_node *rb; |
|
|
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rb = prime_fpriv->dmabufs.rb_node; |
|
while (rb) { |
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struct drm_prime_member *member; |
|
|
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member = rb_entry(rb, struct drm_prime_member, dmabuf_rb); |
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if (member->dma_buf == dma_buf) { |
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rb_erase(&member->handle_rb, &prime_fpriv->handles); |
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rb_erase(&member->dmabuf_rb, &prime_fpriv->dmabufs); |
|
|
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dma_buf_put(dma_buf); |
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kfree(member); |
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return; |
|
} else if (member->dma_buf < dma_buf) { |
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rb = rb->rb_right; |
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} else { |
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rb = rb->rb_left; |
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} |
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} |
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} |
|
|
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void drm_prime_init_file_private(struct drm_prime_file_private *prime_fpriv) |
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{ |
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mutex_init(&prime_fpriv->lock); |
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prime_fpriv->dmabufs = RB_ROOT; |
|
prime_fpriv->handles = RB_ROOT; |
|
} |
|
|
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void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv) |
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{ |
|
/* by now drm_gem_release should've made sure the list is empty */ |
|
WARN_ON(!RB_EMPTY_ROOT(&prime_fpriv->dmabufs)); |
|
} |
|
|
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/** |
|
* 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() |
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* |
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* This wraps dma_buf_export() for use by generic GEM drivers that are using |
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* drm_gem_dmabuf_release(). In addition to calling dma_buf_export(), we take |
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* a reference to the &drm_device and the exported &drm_gem_object (stored in |
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* &dma_buf_export_info.priv) which is released by drm_gem_dmabuf_release(). |
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* |
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* Returns the new dmabuf. |
|
*/ |
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struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev, |
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struct dma_buf_export_info *exp_info) |
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{ |
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struct drm_gem_object *obj = exp_info->priv; |
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struct dma_buf *dma_buf; |
|
|
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dma_buf = dma_buf_export(exp_info); |
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if (IS_ERR(dma_buf)) |
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return dma_buf; |
|
|
|
drm_dev_get(dev); |
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drm_gem_object_get(obj); |
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dma_buf->file->f_mapping = obj->dev->anon_inode->i_mapping; |
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|
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return dma_buf; |
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} |
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EXPORT_SYMBOL(drm_gem_dmabuf_export); |
|
|
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/** |
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* drm_gem_dmabuf_release - &dma_buf release implementation for GEM |
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* @dma_buf: buffer to be released |
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* |
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* 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(). |
|
*/ |
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void drm_gem_dmabuf_release(struct dma_buf *dma_buf) |
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{ |
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struct drm_gem_object *obj = dma_buf->priv; |
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struct drm_device *dev = obj->dev; |
|
|
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/* drop the reference on the export fd holds */ |
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drm_gem_object_put(obj); |
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|
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drm_dev_put(dev); |
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} |
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EXPORT_SYMBOL(drm_gem_dmabuf_release); |
|
|
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/** |
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* drm_gem_prime_fd_to_handle - PRIME import function for GEM drivers |
|
* @dev: dev to export the buffer from |
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* @file_priv: drm file-private structure |
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* @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. |
|
* |
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* Returns 0 on success or a negative error code on failure. |
|
*/ |
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int drm_gem_prime_fd_to_handle(struct drm_device *dev, |
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struct drm_file *file_priv, int prime_fd, |
|
uint32_t *handle) |
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{ |
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struct dma_buf *dma_buf; |
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struct drm_gem_object *obj; |
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int ret; |
|
|
|
dma_buf = dma_buf_get(prime_fd); |
|
if (IS_ERR(dma_buf)) |
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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 |
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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. |
|
* |
|
* Importing 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) { |
|
vma->vm_ops = obj->funcs->vm_ops; |
|
|
|
drm_gem_object_get(obj); |
|
ret = obj->funcs->mmap(obj, vma); |
|
if (ret) { |
|
drm_gem_object_put(obj); |
|
return ret; |
|
} |
|
vma->vm_private_data = 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; |
|
size_t max_segment = 0; |
|
int err; |
|
|
|
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; |
|
err = sg_alloc_table_from_pages_segment(sg, pages, nr_pages, 0, |
|
nr_pages << PAGE_SHIFT, |
|
max_segment, GFP_KERNEL); |
|
if (err) { |
|
kfree(sg); |
|
sg = ERR_PTR(err); |
|
} |
|
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);
|
|
|