[PATCH v1 15/16] xprtrdma: Make rpcrdma_{un}map_one() into inline functions

[Chuck Lever <chuck.lever@oracle.com>]

These functions are called in a loop for each page transferred via
RDMA READ or WRITE. Extract loop invariants and inline them to
reduce CPU overhead.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/fmr_ops.c      |   10 ++++++--
 net/sunrpc/xprtrdma/frwr_ops.c     |   10 ++++++--
 net/sunrpc/xprtrdma/physical_ops.c |   11 ++++++---
 net/sunrpc/xprtrdma/verbs.c        |   44 ++++++-----------------------------
 net/sunrpc/xprtrdma/xprt_rdma.h    |   45 ++++++++++++++++++++++++++++++++++--
 5 files changed, 73 insertions(+), 47 deletions(-)

diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index 9c6c2e8..1404f20 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/net/sunrpc/xprtrdma/fmr_ops.c
@@ -29,14 +29,16 @@ __fmr_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	struct rpcrdma_mr_seg *seg1 = seg;
 	struct rpcrdma_mw *mw = seg1->rl_mw;
+	struct ib_device *device;
 	int rc, nsegs = seg->mr_nsegs;
 	LIST_HEAD(l);
 
 	list_add(&mw->r.fmr->list, &l);
 	rc = ib_unmap_fmr(&l);
 	read_lock(&ia->ri_qplock);
+	device = ia->ri_id->device;
 	while (seg1->mr_nsegs--)
-		rpcrdma_unmap_one(ia, seg++);
+		rpcrdma_unmap_one(device, seg++);
 	read_unlock(&ia->ri_qplock);
 	if (rc)
 		goto out_err;
@@ -150,6 +152,8 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	   int nsegs, bool writing)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+	struct ib_device *device = ia->ri_id->device;
+	enum dma_data_direction direction = rpcrdma_data_dir(writing);
 	struct rpcrdma_mr_seg *seg1 = seg;
 	struct rpcrdma_mw *mw;
 	u64 physaddrs[RPCRDMA_MAX_DATA_SEGS];
@@ -170,7 +174,7 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	if (nsegs > RPCRDMA_MAX_FMR_SGES)
 		nsegs = RPCRDMA_MAX_FMR_SGES;
 	for (i = 0; i < nsegs;) {
-		rpcrdma_map_one(ia, seg, writing);
+		rpcrdma_map_one(device, seg, direction);
 		physaddrs[i] = seg->mr_dma;
 		len += seg->mr_len;
 		++seg;
@@ -197,7 +201,7 @@ out_maperr:
 		__func__, len, (unsigned long long)seg1->mr_dma,
 		pageoff, i, rc);
 	while (i--)
-		rpcrdma_unmap_one(ia, --seg);
+		rpcrdma_unmap_one(device, --seg);
 	rpcrdma_put_mw(r_xprt, mw);
 	return rc;
 }
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index d23e064..4494668 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -55,6 +55,7 @@ __frwr_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 	struct rpcrdma_mr_seg *seg1 = seg;
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	struct rpcrdma_mw *mw = seg1->rl_mw;
+	struct ib_device *device;
 	struct ib_send_wr invalidate_wr, *bad_wr;
 	int rc, nsegs = seg->mr_nsegs;
 
@@ -67,8 +68,9 @@ __frwr_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
 	DECR_CQCOUNT(&r_xprt->rx_ep);
 
 	read_lock(&ia->ri_qplock);
+	device = ia->ri_id->device;
 	while (seg1->mr_nsegs--)
-		rpcrdma_unmap_one(ia, seg++);
+		rpcrdma_unmap_one(device, seg++);
 	rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
 	read_unlock(&ia->ri_qplock);
 	if (rc)
@@ -323,6 +325,8 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 	    int nsegs, bool writing)
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+	struct ib_device *device = ia->ri_id->device;
+	enum dma_data_direction direction = rpcrdma_data_dir(writing);
 	struct rpcrdma_mr_seg *seg1 = seg;
 	struct rpcrdma_frmr *frmr;
 	struct rpcrdma_mw *mw;
@@ -351,7 +355,7 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 		nsegs = ia->ri_max_frmr_depth;
 	frmr = &mw->r.frmr;
 	for (page_no = i = 0; i < nsegs;) {
-		rpcrdma_map_one(ia, seg, writing);
+		rpcrdma_map_one(device, seg, direction);
 		pa = seg->mr_dma;
 		for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) {
 			frmr->fr_pgl->page_list[page_no++] = pa;
@@ -409,7 +413,7 @@ out_senderr:
 out_err:
 	frmr->fr_state = FRMR_IS_INVALID;
 	while (i--)
-		rpcrdma_unmap_one(ia, --seg);
+		rpcrdma_unmap_one(device, --seg);
 	rpcrdma_put_mw(r_xprt, mw);
 	return rc;
 }
diff --git a/net/sunrpc/xprtrdma/physical_ops.c b/net/sunrpc/xprtrdma/physical_ops.c
index 0998f4f..9ce7dfc 100644
--- a/net/sunrpc/xprtrdma/physical_ops.c
+++ b/net/sunrpc/xprtrdma/physical_ops.c
@@ -64,7 +64,8 @@ physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
 {
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 
-	rpcrdma_map_one(ia, seg, writing);
+	rpcrdma_map_one(ia->ri_id->device, seg,
+			rpcrdma_data_dir(writing));
 	seg->mr_rkey = ia->ri_bind_mem->rkey;
 	seg->mr_base = seg->mr_dma;
 	seg->mr_nsegs = 1;
@@ -77,10 +78,14 @@ static void
 physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 		  unsigned int count)
 {
+	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	unsigned int i;
 
-	for (i = 0; i < count; i++)
-		rpcrdma_unmap_one(&r_xprt->rx_ia, &req->rl_segments[i]);
+	for (i = 0; i < count; i++) {
+		read_lock(&ia->ri_qplock);
+		rpcrdma_unmap_one(ia->ri_id->device, &req->rl_segments[i]);
+		read_unlock(&ia->ri_qplock);
+	}
 }
 
 static void
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 21b63fe..460c917 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1288,6 +1288,14 @@ rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
  * Wrappers for internal-use kmalloc memory registration, used by buffer code.
  */
 
+void
+rpcrdma_mapping_error(struct rpcrdma_mr_seg *seg)
+{
+	dprintk("RPC:       map_one: offset %p iova %llx len %zu\n",
+		seg->mr_offset,
+		(unsigned long long)seg->mr_dma, seg->mr_dmalen);
+}
+
 static int
 rpcrdma_register_internal(struct rpcrdma_ia *ia, void *va, int len,
 				struct ib_mr **mrp, struct ib_sge *iov)
@@ -1413,42 +1421,6 @@ rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
 }
 
 /*
- * Wrappers for chunk registration, shared by read/write chunk code.
- */
-
-void
-rpcrdma_map_one(struct rpcrdma_ia *ia, struct rpcrdma_mr_seg *seg, bool writing)
-{
-	seg->mr_dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
-	seg->mr_dmalen = seg->mr_len;
-	if (seg->mr_page)
-		seg->mr_dma = ib_dma_map_page(ia->ri_id->device,
-				seg->mr_page, offset_in_page(seg->mr_offset),
-				seg->mr_dmalen, seg->mr_dir);
-	else
-		seg->mr_dma = ib_dma_map_single(ia->ri_id->device,
-				seg->mr_offset,
-				seg->mr_dmalen, seg->mr_dir);
-	if (ib_dma_mapping_error(ia->ri_id->device, seg->mr_dma)) {
-		dprintk("RPC:       %s: mr_dma %llx mr_offset %p mr_dma_len %zu\n",
-			__func__,
-			(unsigned long long)seg->mr_dma,
-			seg->mr_offset, seg->mr_dmalen);
-	}
-}
-
-void
-rpcrdma_unmap_one(struct rpcrdma_ia *ia, struct rpcrdma_mr_seg *seg)
-{
-	if (seg->mr_page)
-		ib_dma_unmap_page(ia->ri_id->device,
-				seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
-	else
-		ib_dma_unmap_single(ia->ri_id->device,
-				seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
-}
-
-/*
  * Prepost any receive buffer, then post send.
  *
  * Receive buffer is donated to hardware, reclaimed upon recv completion.
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index b167e44..10c4fa5 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -423,11 +423,52 @@ void rpcrdma_free_regbuf(struct rpcrdma_ia *,
 			 struct rpcrdma_regbuf *);
 
 unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
-void rpcrdma_map_one(struct rpcrdma_ia *, struct rpcrdma_mr_seg *, bool);
-void rpcrdma_unmap_one(struct rpcrdma_ia *, struct rpcrdma_mr_seg *);
 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
 
 /*
+ * Wrappers for chunk registration, shared by read/write chunk code.
+ */
+
+void rpcrdma_mapping_error(struct rpcrdma_mr_seg *);
+
+static inline enum dma_data_direction
+rpcrdma_data_dir(bool writing)
+{
+	return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+}
+
+static inline void
+rpcrdma_map_one(struct ib_device *device, struct rpcrdma_mr_seg *seg,
+		enum dma_data_direction direction)
+{
+	seg->mr_dir = direction;
+	seg->mr_dmalen = seg->mr_len;
+
+	if (seg->mr_page)
+		seg->mr_dma = ib_dma_map_page(device,
+				seg->mr_page, offset_in_page(seg->mr_offset),
+				seg->mr_dmalen, seg->mr_dir);
+	else
+		seg->mr_dma = ib_dma_map_single(device,
+				seg->mr_offset,
+				seg->mr_dmalen, seg->mr_dir);
+
+	if (ib_dma_mapping_error(device, seg->mr_dma))
+		rpcrdma_mapping_error(seg);
+}
+
+static inline void
+rpcrdma_unmap_one(struct ib_device *device, struct rpcrdma_mr_seg *seg)
+{
+	if (seg->mr_page)
+		ib_dma_unmap_page(device,
+				  seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
+	else
+		ib_dma_unmap_single(device,
+				    seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
+}
+
+/*
  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
  */
 void rpcrdma_connect_worker(struct work_struct *);