| Message ID | 20220831153757.97381-17-dmitry.osipenko@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Move all drivers to a common dma-buf locking convention | expand |
Am 31.08.22 um 17:37 schrieb Dmitry Osipenko: > Move dma-buf attachment API functions to the dynamic locking specification > by taking the reservation lock around the mapping operations. The strict > locking convention prevents deadlock situations for dma-buf importers and > exporters. > > Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Reviewed-by: Christian König <christian.koenig@amd.com> > --- > drivers/dma-buf/dma-buf.c | 20 ++++++++------------ > 1 file changed, 8 insertions(+), 12 deletions(-) > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index ceea4839c641..073942bf5ae9 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -858,8 +858,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, > dma_buf_is_dynamic(dmabuf)) { > struct sg_table *sgt; > > + dma_resv_lock(attach->dmabuf->resv, NULL); > if (dma_buf_is_dynamic(attach->dmabuf)) { > - dma_resv_lock(attach->dmabuf->resv, NULL); > ret = dmabuf->ops->pin(attach); > if (ret) > goto err_unlock; > @@ -872,8 +872,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, > ret = PTR_ERR(sgt); > goto err_unpin; > } > - if (dma_buf_is_dynamic(attach->dmabuf)) > - dma_resv_unlock(attach->dmabuf->resv); > + dma_resv_unlock(attach->dmabuf->resv); > attach->sgt = sgt; > attach->dir = DMA_BIDIRECTIONAL; > } > @@ -889,8 +888,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, > dmabuf->ops->unpin(attach); > > err_unlock: > - if (dma_buf_is_dynamic(attach->dmabuf)) > - dma_resv_unlock(attach->dmabuf->resv); > + dma_resv_unlock(attach->dmabuf->resv); > > dma_buf_detach(dmabuf, attach); > return ERR_PTR(ret); > @@ -936,21 +934,19 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) > if (WARN_ON(!dmabuf || !attach)) > return; > > + dma_resv_lock(attach->dmabuf->resv, NULL); > + > if (attach->sgt) { > - if (dma_buf_is_dynamic(attach->dmabuf)) > - dma_resv_lock(attach->dmabuf->resv, NULL); > > __unmap_dma_buf(attach, attach->sgt, attach->dir); > > - if (dma_buf_is_dynamic(attach->dmabuf)) { > + if (dma_buf_is_dynamic(attach->dmabuf)) > dmabuf->ops->unpin(attach); > - dma_resv_unlock(attach->dmabuf->resv); > - } > } > - > - dma_resv_lock(dmabuf->resv, NULL); > list_del(&attach->node); > + > dma_resv_unlock(dmabuf->resv); > + > if (dmabuf->ops->detach) > dmabuf->ops->detach(dmabuf, attach); >
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index ceea4839c641..073942bf5ae9 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -858,8 +858,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, dma_buf_is_dynamic(dmabuf)) { struct sg_table *sgt; + dma_resv_lock(attach->dmabuf->resv, NULL); if (dma_buf_is_dynamic(attach->dmabuf)) { - dma_resv_lock(attach->dmabuf->resv, NULL); ret = dmabuf->ops->pin(attach); if (ret) goto err_unlock; @@ -872,8 +872,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, ret = PTR_ERR(sgt); goto err_unpin; } - if (dma_buf_is_dynamic(attach->dmabuf)) - dma_resv_unlock(attach->dmabuf->resv); + dma_resv_unlock(attach->dmabuf->resv); attach->sgt = sgt; attach->dir = DMA_BIDIRECTIONAL; } @@ -889,8 +888,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, dmabuf->ops->unpin(attach); err_unlock: - if (dma_buf_is_dynamic(attach->dmabuf)) - dma_resv_unlock(attach->dmabuf->resv); + dma_resv_unlock(attach->dmabuf->resv); dma_buf_detach(dmabuf, attach); return ERR_PTR(ret); @@ -936,21 +934,19 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (WARN_ON(!dmabuf || !attach)) return; + dma_resv_lock(attach->dmabuf->resv, NULL); + if (attach->sgt) { - if (dma_buf_is_dynamic(attach->dmabuf)) - dma_resv_lock(attach->dmabuf->resv, NULL); __unmap_dma_buf(attach, attach->sgt, attach->dir); - if (dma_buf_is_dynamic(attach->dmabuf)) { + if (dma_buf_is_dynamic(attach->dmabuf)) dmabuf->ops->unpin(attach); - dma_resv_unlock(attach->dmabuf->resv); - } } - - dma_resv_lock(dmabuf->resv, NULL); list_del(&attach->node); + dma_resv_unlock(dmabuf->resv); + if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach);
Move dma-buf attachment API functions to the dynamic locking specification by taking the reservation lock around the mapping operations. The strict locking convention prevents deadlock situations for dma-buf importers and exporters. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> --- drivers/dma-buf/dma-buf.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-)