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@xxxxxxxxxx>
---
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;
--
2.17.1
