[PATCH] svc_rdma: use local_dma_lkey

Christoph Hellwig
2015-12-16T15:11:04Z

We now alwasy have a per-PD local_dma_lkey available. Make use of that
fact in svc_rdma and stop registering our own MR.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
include/linux/sunrpc/svc_rdma.h | 2 --
net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 2 +-
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 4 ++--
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 6 ++---
net/sunrpc/xprtrdma/svc_rdma_transport.c | 36 ++++--------------------------
5 files changed, 10 insertions(+), 40 deletions(-)

diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index b13513a..5322fea 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -156,13 +156,11 @@ struct svcxprt_rdma {
struct ib_qp *sc_qp;
struct ib_cq *sc_rq_cq;
struct ib_cq *sc_sq_cq;
- struct ib_mr *sc_phys_mr; /* MR for server memory */
int (*sc_reader)(struct svcxprt_rdma *,
struct svc_rqst *,
struct svc_rdma_op_ctxt *,
int *, u32 *, u32, u32, u64, bool);
u32 sc_dev_caps; /* distilled device caps */
- u32 sc_dma_lkey; /* local dma key */
unsigned int sc_frmr_pg_list_len;
struct list_head sc_frmr_q;
spinlock_t sc_frmr_q_lock;
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
index 417cec1..c428734 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -128,7 +128,7 @@ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma,

ctxt->wr_op = IB_WR_SEND;
ctxt->direction = DMA_TO_DEVICE;
- ctxt->sge[0].lkey = rdma->sc_dma_lkey;
+ ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey;
ctxt->sge[0].length = sndbuf->len;
ctxt->sge[0].addr =
ib_dma_map_page(rdma->sc_cm_id->device, ctxt->pages[0], 0,
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 3dfe464..c8b8a8b 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -144,6 +144,7 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,

head->arg.pages[pg_no] = rqstp->rq_arg.pages[pg_no];
head->arg.page_len += len;
+
head->arg.len += len;
if (!pg_off)
head->count++;
@@ -160,8 +161,7 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt,
goto err;
atomic_inc(&xprt->sc_dma_used);

- /* The lkey here is either a local dma lkey or a dma_mr lkey */
- ctxt->sge[pno].lkey = xprt->sc_dma_lkey;
+ ctxt->sge[pno].lkey = xprt->sc_pd->local_dma_lkey;
ctxt->sge[pno].length = len;
ctxt->count++;

diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index ced3151..20bd5d4 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -265,7 +265,7 @@ static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
sge[sge_no].addr))
goto err;
atomic_inc(&xprt->sc_dma_used);
- sge[sge_no].lkey = xprt->sc_dma_lkey;
+ sge[sge_no].lkey = xprt->sc_pd->local_dma_lkey;
ctxt->count++;
sge_off = 0;
sge_no++;
@@ -487,7 +487,7 @@ static int send_reply(struct svcxprt_rdma *rdma,
ctxt->count = 1;

/* Prepare the SGE for the RPCRDMA Header */
- ctxt->sge[0].lkey = rdma->sc_dma_lkey;
+ ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey;
ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
ctxt->sge[0].addr =
ib_dma_map_page(rdma->sc_cm_id->device, page, 0,
@@ -511,7 +511,7 @@ static int send_reply(struct svcxprt_rdma *rdma,
ctxt->sge[sge_no].addr))
goto err;
atomic_inc(&rdma->sc_dma_used);
- ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey;
+ ctxt->sge[sge_no].lkey = rdma->sc_pd->local_dma_lkey;
ctxt->sge[sge_no].length = sge_bytes;
}
if (byte_count != 0) {
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index abfbd02..faf4c49 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -232,11 +232,11 @@ void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt)
for (i = 0; i < ctxt->count && ctxt->sge[i].length; i++) {
/*
* Unmap the DMA addr in the SGE if the lkey matches
- * the sc_dma_lkey, otherwise, ignore it since it is
+ * the local_dma_lkey, otherwise, ignore it since it is
* an FRMR lkey and will be unmapped later when the
* last WR that uses it completes.
*/
- if (ctxt->sge[i].lkey == xprt->sc_dma_lkey) {
+ if (ctxt->sge[i].lkey == xprt->sc_pd->local_dma_lkey) {
atomic_dec(&xprt->sc_dma_used);
ib_dma_unmap_page(xprt->sc_cm_id->device,
ctxt->sge[i].addr,
@@ -698,7 +698,7 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt, gfp_t flags)
atomic_inc(&xprt->sc_dma_used);
ctxt->sge[sge_no].addr = pa;
ctxt->sge[sge_no].length = PAGE_SIZE;
- ctxt->sge[sge_no].lkey = xprt->sc_dma_lkey;
+ ctxt->sge[sge_no].lkey = xprt->sc_pd->local_dma_lkey;
ctxt->count = sge_no + 1;
buflen += PAGE_SIZE;
}
@@ -1014,8 +1014,6 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
struct ib_cq_init_attr cq_attr = {};
struct ib_qp_init_attr qp_attr;
struct ib_device *dev;
- int uninitialized_var(dma_mr_acc);
- int need_dma_mr = 0;
unsigned int i;
int ret = 0;

@@ -1160,32 +1158,9 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
!rdma_ib_or_roce(dev, newxprt->sc_cm_id->port_num))
goto errout;

- if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG) ||
- !(dev->device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) {
- need_dma_mr = 1;
- dma_mr_acc = IB_ACCESS_LOCAL_WRITE;
- if (rdma_protocol_iwarp(dev, newxprt->sc_cm_id->port_num) &&
- !(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG))
- dma_mr_acc |= IB_ACCESS_REMOTE_WRITE;
- }
-
if (rdma_protocol_iwarp(dev, newxprt->sc_cm_id->port_num))
newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_READ_W_INV;

- /* Create the DMA MR if needed, otherwise, use the DMA LKEY */
- if (need_dma_mr) {
- /* Register all of physical memory */
- newxprt->sc_phys_mr =
- ib_get_dma_mr(newxprt->sc_pd, dma_mr_acc);
- if (IS_ERR(newxprt->sc_phys_mr)) {
- dprintk("svcrdma: Failed to create DMA MR ret=%d\n",
- ret);
- goto errout;
- }
- newxprt->sc_dma_lkey = newxprt->sc_phys_mr->lkey;
- } else
- newxprt->sc_dma_lkey = dev->local_dma_lkey;
-
/* Post receive buffers */
for (i = 0; i < newxprt->sc_rq_depth; i++) {
ret = svc_rdma_post_recv(newxprt, GFP_KERNEL);
@@ -1349,9 +1324,6 @@ static void __svc_rdma_free(struct work_struct *work)
if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq))
ib_destroy_cq(rdma->sc_rq_cq);

- if (rdma->sc_phys_mr && !IS_ERR(rdma->sc_phys_mr))
- ib_dereg_mr(rdma->sc_phys_mr);
-
if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
ib_dealloc_pd(rdma->sc_pd);

@@ -1479,7 +1451,7 @@ void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
return;
}
atomic_inc(&xprt->sc_dma_used);
- ctxt->sge[0].lkey = xprt->sc_dma_lkey;
+ ctxt->sge[0].lkey = xprt->sc_pd->local_dma_lkey;
ctxt->sge[0].length = length;

/* Prepare SEND WR */
--
1.9.1