diff options
| author | Dmitry Osipenko <dmitry.osipenko@collabora.com> | 2023-05-30 01:39:34 +0300 |
|---|---|---|
| committer | Dmitry Osipenko <dmitry.osipenko@collabora.com> | 2023-06-21 20:22:20 +0300 |
| commit | 8021fa16b7ec0a3b0457dc15484a7691f99265bc (patch) | |
| tree | 8a703514884bca6446b0ecf6139e8b55d8ef268a /drivers/dma-buf | |
| parent | 11f38236f7bb51c04164e0f5a9630cc6b2f9e099 (diff) | |
dma-buf: Change locking policy for mmap()
Change locking policy of mmap() callback, making exporters responsible
for handling dma-buf reservation locking. Previous locking policy stated
that dma-buf is locked for both importers and exporters by the dma-buf
core, which caused a deadlock problem for DRM drivers in a case of
self-imported dma-bufs which required to take the lock from the DRM
exporter side.
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230529223935.2672495-6-dmitry.osipenko@collabora.com
Diffstat (limited to 'drivers/dma-buf')
| -rw-r--r-- | drivers/dma-buf/dma-buf.c | 17 |
1 files changed, 3 insertions, 14 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index aa4ea8530cb3..21916bba77d5 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -131,7 +131,6 @@ static struct file_system_type dma_buf_fs_type = { static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) { struct dma_buf *dmabuf; - int ret; if (!is_dma_buf_file(file)) return -EINVAL; @@ -147,11 +146,7 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) dmabuf->size >> PAGE_SHIFT) return -EINVAL; - dma_resv_lock(dmabuf->resv, NULL); - ret = dmabuf->ops->mmap(dmabuf, vma); - dma_resv_unlock(dmabuf->resv); - - return ret; + return dmabuf->ops->mmap(dmabuf, vma); } static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) @@ -850,6 +845,7 @@ static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach, * - &dma_buf_ops.release() * - &dma_buf_ops.begin_cpu_access() * - &dma_buf_ops.end_cpu_access() + * - &dma_buf_ops.mmap() * * 2. These &dma_buf_ops callbacks are invoked with locked dma-buf * reservation and exporter can't take the lock: @@ -858,7 +854,6 @@ static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach, * - &dma_buf_ops.unpin() * - &dma_buf_ops.map_dma_buf() * - &dma_buf_ops.unmap_dma_buf() - * - &dma_buf_ops.mmap() * - &dma_buf_ops.vmap() * - &dma_buf_ops.vunmap() * @@ -1463,8 +1458,6 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF); int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, unsigned long pgoff) { - int ret; - if (WARN_ON(!dmabuf || !vma)) return -EINVAL; @@ -1485,11 +1478,7 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, vma_set_file(vma, dmabuf->file); vma->vm_pgoff = pgoff; - dma_resv_lock(dmabuf->resv, NULL); - ret = dmabuf->ops->mmap(dmabuf, vma); - dma_resv_unlock(dmabuf->resv); - - return ret; + return dmabuf->ops->mmap(dmabuf, vma); } EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF); |