First step towards unpinned DMA buf operation. I've checked the DRM drivers to potential locking of the reservation object, but essentially we need to audit all implementations of the dma_buf _ops for this to work. Signed-off-by: Christian König <christian.koenig@xxxxxxx> --- drivers/dma-buf/dma-buf.c | 4 ++++ include/linux/dma-buf.h | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index e4c657d9fad7..4f0708cb58a7 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -631,7 +631,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL); + reservation_object_lock(attach->dmabuf->resv, NULL); sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); + reservation_object_unlock(attach->dmabuf->resv); if (!sg_table) sg_table = ERR_PTR(-ENOMEM); @@ -658,8 +660,10 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return; + reservation_object_lock(attach->dmabuf->resv, NULL); attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); + reservation_object_unlock(attach->dmabuf->resv); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index d17cadd76802..d2ba7a027a78 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -118,6 +118,8 @@ struct dma_buf_ops { * any other kind of sharing that the exporter might wish to make * available to buffer-users. * + * This is called with the dmabuf->resv object locked. + * * Returns: * * A &sg_table scatter list of or the backing storage of the DMA buffer, @@ -138,6 +140,8 @@ struct dma_buf_ops { * It should also unpin the backing storage if this is the last mapping * of the DMA buffer, it the exporter supports backing storage * migration. + * + * This is called with the dmabuf->resv object locked. */ void (*unmap_dma_buf)(struct dma_buf_attachment *, struct sg_table *, -- 2.14.1 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel