This way we always call the the map/unmap callbacks with the reservation object held if pin/unpin is also implemented.
For static dma-buf exporters we still have the fallback of using cached sgt.
v2: reordered v3: rebased on sgt caching v4: use the cached sgt when possible v5: cleanup further
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/dma-buf/dma-buf.c | 10 +++++----- include/linux/dma-buf.h | 3 +++ 2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index a18d10c4425a..0aa97bb05636 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -691,13 +691,15 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
reservation_object_lock(attach->dmabuf->resv, NULL); r = dma_buf_pin(attach->dmabuf); - reservation_object_unlock(attach->dmabuf->resv); - if (r) + if (r) { + reservation_object_unlock(attach->dmabuf->resv); return ERR_PTR(r); + }
sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); if (!sg_table) sg_table = ERR_PTR(-ENOMEM); + reservation_object_unlock(attach->dmabuf->resv);
return sg_table; } @@ -725,10 +727,8 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (attach->sgt == sg_table) return;
- attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, - direction); - reservation_object_lock(attach->dmabuf->resv, NULL); + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); dma_buf_unpin(attach->dmabuf); reservation_object_unlock(attach->dmabuf->resv); } diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index b9d0719581cd..425a771d229c 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -144,6 +144,9 @@ struct dma_buf_ops { * any other kind of sharing that the exporter might wish to make * available to buffer-users. * + * This is always called with the dmabuf->resv object locked when + * the pin/unpin callbacks are implemented. + * * Returns: * * A &sg_table scatter list of or the backing storage of the DMA buffer,