2021-02-04 19:27:57

by Chuck Lever III

[permalink] [raw]
Subject: [PATCH v4 2/6] xprtrdma: Simplify rpcrdma_convert_kvec() and frwr_map()

Clean up.

Remove a conditional branch from the SGL set-up loop in frwr_map():
Instead of using either sg_set_page() or sg_set_buf(), initialize
the mr_page field properly when rpcrdma_convert_kvec() converts the
kvec to an SGL entry. frwr_map() can then invoke sg_set_page()
unconditionally.

Signed-off-by: Chuck Lever <[email protected]>
Reviewed-by: Tom Talpey <[email protected]>
---
net/sunrpc/xprtrdma/frwr_ops.c | 12 ++++--------
net/sunrpc/xprtrdma/rpc_rdma.c | 2 +-
net/sunrpc/xprtrdma/xprt_rdma.h | 9 +++++----
3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index baca49fe83af..13a50f77dddb 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -306,14 +306,10 @@ struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
if (nsegs > ep->re_max_fr_depth)
nsegs = ep->re_max_fr_depth;
for (i = 0; i < nsegs;) {
- if (seg->mr_page)
- sg_set_page(&mr->mr_sg[i],
- seg->mr_page,
- seg->mr_len,
- offset_in_page(seg->mr_offset));
- else
- sg_set_buf(&mr->mr_sg[i], seg->mr_offset,
- seg->mr_len);
+ sg_set_page(&mr->mr_sg[i],
+ seg->mr_page,
+ seg->mr_len,
+ offset_in_page(seg->mr_offset));

++seg;
++i;
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 57f9217048d8..b36b9aae0588 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -213,7 +213,7 @@ static struct rpcrdma_mr_seg *
rpcrdma_convert_kvec(struct kvec *vec, struct rpcrdma_mr_seg *seg,
unsigned int *n)
{
- seg->mr_page = NULL;
+ seg->mr_page = virt_to_page(vec->iov_base);
seg->mr_offset = vec->iov_base;
seg->mr_len = vec->iov_len;
++seg;
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 94b28657aeeb..02971e183989 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -283,10 +283,11 @@ enum {
RPCRDMA_MAX_IOV_SEGS,
};

-struct rpcrdma_mr_seg { /* chunk descriptors */
- u32 mr_len; /* length of chunk or segment */
- struct page *mr_page; /* owning page, if any */
- char *mr_offset; /* kva if no page, else offset */
+/* Arguments for DMA mapping and registration */
+struct rpcrdma_mr_seg {
+ u32 mr_len; /* length of segment */
+ struct page *mr_page; /* underlying struct page */
+ char *mr_offset; /* IN: page offset, OUT: iova */
};

/* The Send SGE array is provisioned to send a maximum size