Current implementation requires a dma device for RDMA driver to use dma-buf memory space as RDMA buffer. However, software RDMA drivers has not dma device and copy RDMA data using CPU instead of hardware.
This patch changes to be hold a dma-buf on struct ib_umem_dmabuf. This allows the software RDMA driver to map dma-buf memory for CPU memory accessing.
Signed-off-by: Shunsuke Mie mie@igel.co.jp --- drivers/infiniband/core/umem_dmabuf.c | 20 ++++++++++++++++---- include/rdma/ib_umem.h | 1 + 2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c index e824baf4640d..ebbb0a259fd4 100644 --- a/drivers/infiniband/core/umem_dmabuf.c +++ b/drivers/infiniband/core/umem_dmabuf.c @@ -117,9 +117,6 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, if (check_add_overflow(offset, (unsigned long)size, &end)) return ret;
- if (unlikely(!ops || !ops->move_notify)) - return ret; - dmabuf = dma_buf_get(fd); if (IS_ERR(dmabuf)) return ERR_CAST(dmabuf); @@ -133,6 +130,8 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, goto out_release_dmabuf; }
+ umem_dmabuf->dmabuf = dmabuf; + umem = &umem_dmabuf->umem; umem->ibdev = device; umem->length = size; @@ -143,6 +142,13 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, if (!ib_umem_num_pages(umem)) goto out_free_umem;
+ /* Software RDMA drivers has not dma device. Just get dmabuf from fd */ + if (!device->dma_device) + goto done; + + if (unlikely(!ops || !ops->move_notify)) + goto out_free_umem; + umem_dmabuf->attach = dma_buf_dynamic_attach( dmabuf, device->dma_device, @@ -152,6 +158,7 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, ret = ERR_CAST(umem_dmabuf->attach); goto out_free_umem; } +done: return umem_dmabuf;
out_free_umem: @@ -165,13 +172,18 @@ EXPORT_SYMBOL(ib_umem_dmabuf_get);
void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { - struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf; + struct dma_buf *dmabuf = umem_dmabuf->dmabuf; + + if (!umem_dmabuf->attach) + goto free_dmabuf;
dma_resv_lock(dmabuf->resv, NULL); ib_umem_dmabuf_unmap_pages(umem_dmabuf); dma_resv_unlock(dmabuf->resv);
dma_buf_detach(dmabuf, umem_dmabuf->attach); + +free_dmabuf: dma_buf_put(dmabuf); kfree(umem_dmabuf); } diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index 5ae9dff74dac..11c0cf7e0dd8 100644 --- a/include/rdma/ib_umem.h +++ b/include/rdma/ib_umem.h @@ -32,6 +32,7 @@ struct ib_umem { struct ib_umem_dmabuf { struct ib_umem umem; struct dma_buf_attachment *attach; + struct dma_buf *dmabuf; struct sg_table *sgt; struct scatterlist *first_sg; struct scatterlist *last_sg;