[PATCH V5 4/5] RDMA/isert: Set REMOTE_WRITE on DMA MRs to support iWARP devices

Steve Wise
2015-07-05T17:45:00Z

iWARP devices require REMOTE_WRITE for MRs used as the destination of
an RDMA READ. So if the device protocol is iWARP, then set REMOTE_WRITE
when allocating the DMA MR.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
---

drivers/infiniband/ulp/isert/ib_isert.c | 22 +++++++++++++++++++++-
1 files changed, 21 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 9e7b492..ee40478 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -348,6 +348,17 @@ out_cq:
return ret;
}

+static int any_port_is_iwarp(struct isert_device *device)
+{
+ int i;
+
+ for (i = rdma_start_port(device->ib_device);
+ i <= rdma_end_port(device->ib_device); i++)
+ if (rdma_protocol_iwarp(device->ib_device, i))
+ return 1;
+ return 0;
+}
+
static int
isert_create_device_ib_res(struct isert_device *device)
{
@@ -383,7 +394,16 @@ isert_create_device_ib_res(struct isert_device *device)
goto out_cq;
}

- device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE);
+ /*
+ * IWARP transports need REMOTE_WRITE for MRs used as the target of
+ * an RDMA_READ. Since the DMA MR is used for all ports, then if
+ * any port is running IWARP, add REMOTE_WRITE.
+ */
+ if (any_port_is_iwarp(device))
+ device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
+ IB_ACCESS_REMOTE_WRITE);
+ else
+ device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE);
if (IS_ERR(device->mr)) {
ret = PTR_ERR(device->mr);
isert_err("failed to create dma mr, device %p, ret=%d\n",