/*
* Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the BSD-type
* license below:
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* Neither the name of the Network Appliance, Inc. nor the names of
* its contributors may be used to endorse or promote products
* derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Author: Tom Tucker <tom@opengridcomputing.com>
*/
#include <linux/sunrpc/debug.h>
#include <linux/sunrpc/rpc_rdma.h>
#include <linux/spinlock.h>
#include <asm/unaligned.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
#include <linux/sunrpc/svc_rdma.h>
#define RPCDBG_FACILITY RPCDBG_SVCXPRT
/* Encode an XDR as an array of IB SGE
*
* Assumptions:
* - head[0] is physically contiguous.
* - tail[0] is physically contiguous.
* - pages[] is not physically or virtually contigous and consists of
* PAGE_SIZE elements.
*
* Output:
* SGE[0] reserved for RCPRDMA header
* SGE[1] data from xdr->head[]
* SGE[2..sge_count-2] data from xdr->pages[]
* SGE[sge_count-1] data from xdr->tail.
*
*/
static struct ib_sge *xdr_to_sge(struct svcxprt_rdma *xprt,
struct xdr_buf *xdr,
struct ib_sge *sge,
int *sge_count)
{
/* Max we need is the length of the XDR / pagesize + one for
* head + one for tail + one for RPCRDMA header
*/
int sge_max = (xdr->len+PAGE_SIZE-1) / PAGE_SIZE + 3;
int sge_no;
u32 byte_count = xdr->len;
u32 sge_bytes;
u32 page_bytes;
int page_off;
int page_no;
/* Skip the first sge, this is for the RPCRDMA header */
sge_no = 1;
/* Head SGE */
sge[sge_no].addr = ib_dma_map_single(xprt->sc_cm_id->device,
xdr->head[0].iov_base,
xdr->head[0].iov_len,
DMA_TO_DEVICE);
sge_bytes = min_t(u32, byte_count, xdr->head[0].iov_len);
byte_count -= sge_bytes;
sge[sge_no].length = sge_bytes;
sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
sge_no++;
/* pages SGE */
page_no = 0;
page_bytes = xdr->page_len;
page_off = xdr->page_base;
while (byte_count && page_bytes) {
sge_bytes = min_t(u32, byte_count, (PAGE_SIZE-page_off));
sge[sge_no].addr =
ib_dma_map_page(xprt->sc_cm_id->device,
xdr->pages[page_no], page_off,
sge_bytes, DMA_TO_DEVICE);
sge_bytes = min(sge_bytes, page_bytes);
byte_count -= sge_bytes;
page_bytes -= sge_bytes;
sge[sge_no].length = sge_bytes;
sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
sge_no++;
page_no++;
page_off = 0; /* reset for next time through loop */
}
/* Tail SGE */
if (byte_count && xdr->tail[0].iov_len) {
sge[sge_no].addr =
ib_dma_map_single(xprt->sc_cm_id->device,
xdr->tail[0].iov_base,
xdr->tail[0].iov_len,
DMA_TO_DEVICE);
sge_bytes = min_t(u32, byte_count, xdr->tail[0].iov_len);
byte_count -= sge_bytes;
sge[sge_no].length = sge_bytes;
sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
sge_no++;
}
BUG_ON(sge_no > sge_max);
BUG_ON(byte_count != 0);
*sge_count = sge_no;
return sge;
}
/* Assumptions:
* - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
*/
static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
u32 rmr, u64 to,
u32 xdr_off, int write_len,
struct ib_sge *xdr_sge, int sge_count)
{
struct svc_rdma_op_ctxt *tmp_sge_ctxt;
struct ib_send_wr write_wr;
struct ib_sge *sge;
int xdr_sge_no;
int sge_no;
int sge_bytes;
int sge_off;
int bc;
struct svc_rdma_op_ctxt *ctxt;
int ret = 0;
BUG_ON(sge_count >= 32);
dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
"write_len=%d, xdr_sge=%p, sge_count=%d\n",
rmr, (unsigned long long)to, xdr_off,
write_len, xdr_sge, sge_count);
ctxt = svc_rdma_get_context(xprt);
ctxt->count = 0;
tmp_sge_ctxt = svc_rdma_get_context(xprt);
sge = tmp_sge_ctxt->sge;
/* Find the SGE associated with xdr_off */
for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < sge_count;
xdr_sge_no++) {
if (xdr_sge[xdr_sge_no].length > bc)
break;
bc -= xdr_sge[xdr_sge_no].length;
}
sge_off = bc;
bc = write_len;
sge_no = 0;
/* Copy the remaining SGE */
while (bc != 0 && xdr_sge_no < sge_count) {
sge[sge_no].addr = xdr_sge[xdr_sge_no].addr + sge_off;
sge[sge_no].lkey = xdr_sge[xdr_sge_no].lkey;
sge_bytes = min((size_t)bc,
(size_t)(xdr_sge[xdr_sge_no].length-sge_off));
sge[sge_no].length = sge_bytes;
sge_off = 0;
sge_no++;
xdr_sge_no++;
bc -= sge_bytes;
}
BUG_ON(bc != 0);
BUG_ON(xdr_sge_no > sge_count);
/* Prepare WRITE WR */
memset(&write_wr, 0, sizeof write_wr);
ctxt->wr_op = IB_WR_RDMA_WRITE;
write_wr.wr_id = (unsigned long)ctxt;
write_wr.sg_list = &sge[0];
write_wr.num_sge = sge_no;
write_wr.opcode = IB_WR_RDMA_WRITE;
write_wr.send_flags = IB_SEND_SIGNALED;
write_wr.wr.rdma.rkey = rmr;
write_wr.wr.rdma.remote_addr = to;
/* Post It */
atomic_inc(&rdma_stat_write);
if (svc_rdma_send(xprt, &write_wr)) {
svc_rdma_put_context(ctxt, 1);
/* Fatal error, close transport */
ret = -EIO;
}
svc_rdma_put_context(tmp_sge_ctxt, 0);
return ret;
}
static int send_write_chunks(struct svcxprt_rdma *xprt,
struct rpcrdma_msg *rdma_argp,
struct rpcrdma_msg *rdma_resp,
struct svc_rqst *rqstp,
struct ib_sge *sge,
int sge_count)
{
u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
int write_len;
int max_write;
u32 xdr_off;
int chunk_off;
int chunk_no;
struct rpcrdma_write_array *arg_ary;
struct rpcrdma_write_array *res_ary;
int ret;
arg_ary = svc_rdma_get_write_array(rdma_argp);
if (!arg_ary)
return 0;
res_ary = (struct rpcrdma_write_array *)
&rdma_resp->rm_body.rm_chunks[1];
max_write = xprt->sc_max_sge * PAGE_SIZE;
/* Write chunks start at the pagelist */
for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0;
xfer_len && chunk_no < arg_ary->wc_nchunks;
chunk_no++) {
struct rpcrdma_segment *arg_ch;
u64 rs_offset;
arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
write_len = min(xfer_len, arg_ch->rs_length);
/* Prepare the response chunk given the length actually
* written */
rs_offset = get_unaligned(&(arg_ch->rs_offset));
svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
arg_ch->rs_handle,
rs_offset,
write_len);
chunk_off = 0;
while (write_len) {
int this_write;
this_write = min(write_len, max_write);
ret = send_write(xprt, rqstp,
arg_ch->rs_handle,
rs_offset + chunk_off,
xdr_off,
this_write,
sge,
sge_count);
if (ret) {
dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
ret);
return -EIO;
}
chunk_off += this_write;
xdr_off += this_write;
xfer_len -= this_write;
write_len -= this_write;
}
}
/* Update the req with the number of chunks actually used */
svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no);
return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
}
static int send_reply_chunks(struct svcxprt_rdma *xprt,
struct rpcrdma_msg *rdma_argp,
struct rpcrdma_msg *rdma_resp,
struct svc_rqst *rqstp,
struct ib_sge *sge,
int sge_count)
{
u32 xfer_len = rqstp->rq_res.len;
int write_len;
int max_write;
u32 xdr_off;
int chunk_no;
int chunk_off;
struct rpcrdma_segment *ch;
struct rpcrdma_write_array *arg_ary;
struct rpcrdma_write_array *res_ary;
int ret;
arg_ary = svc_rdma_get_reply_array(rdma_argp);
if (!arg_ary)
return 0;
/* XXX: need to fix when reply lists occur with read-list and or
* write-list */
res_ary = (struct rpcrdma_write_array *)
&rdma_resp->rm_body.rm_chunks[2];
max_write = xprt->sc_max_sge * PAGE_SIZE;
/* xdr offset starts at RPC message */
for (xdr_off = 0, chunk_no = 0;
xfer_len && chunk_no < arg_ary->wc_nchunks;
chunk_no++) {
u64 rs_offset;
ch = &arg_ary->wc_array[chunk_no].wc_target;
write_len = min(xfer_len, ch->rs_length);
/* Prepare the reply chunk given the length actually
* written */
rs_offset = get_unaligned(&(ch->rs_offset));
svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
ch->rs_handle, rs_offset,
write_len);
chunk_off = 0;
while (write_len) {
int this_write;
this_write = min(write_len, max_write);
ret = send_write(xprt, rqstp,
ch->rs_handle,
rs_offset + chunk_off,
xdr_off,
this_write,
sge,
sge_count);
if (ret) {
dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
ret);
return -EIO;
}
chunk_off += this_write;
xdr_off += this_write;
xfer_len -= this_write;
write_len -= this_write;
}
}
/* Update the req with the number of chunks actually used */
svc_rdma_xdr_encode_reply_array(res_ary, chunk_no);
return rqstp->rq_res.len;
}
/* This function prepares the portion of the RPCRDMA message to be
* sent in the RDMA_SEND. This function is called after data sent via
* RDMA has already been transmitted. There are three cases:
* - The RPCRDMA header, RPC header, and payload are all sent in a
* single RDMA_SEND. This is the "inline" case.
* - The RPCRDMA header and some portion of the RPC header and data
* are sent via this RDMA_SEND and another portion of the data is
* sent via RDMA.
* - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC
* header and data are all transmitted via RDMA.
* In all three cases, this function prepares the RPCRDMA header in
* sge[0], the 'type' parameter indicates the type to place in the
* RPCRDMA header, and the 'byte_count' field indicates how much of
* the XDR to include in this RDMA_SEND.
*/
static int send_reply(struct svcxprt_rdma *rdma,
struct svc_rqst *rqstp,
struct page *page,
struct rpcrdma_msg *rdma_resp,
struct svc_rdma_op_ctxt *ctxt,
int sge_count,
int byte_count)
{
struct ib_send_wr send_wr;
int sge_no;
int sge_bytes;
int page_no;
int ret;
/* Prepare the context */
ctxt->pages[0] = page;
ctxt->count = 1;
/* Prepare the SGE for the RPCRDMA Header */
ctxt->sge[0].addr =
ib_dma_map_page(rdma->sc_cm_id->device,
page, 0, PAGE_SIZE, DMA_TO_DEVICE);
ctxt->direction = DMA_TO_DEVICE;
ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
ctxt->sge[0].lkey = rdma->sc_phys_mr->lkey;
/* Determine how many of our SGE are to be transmitted */
for (sge_no = 1; byte_count && sge_no < sge_count; sge_no++) {
sge_bytes = min((size_t)ctxt->sge[sge_no].length,
(size_t)byte_count);
byte_count -= sge_bytes;
}
BUG_ON(byte_count != 0);
/* Save all respages in the ctxt and remove them from the
* respages array. They are our pages until the I/O
* completes.
*/
for (page_no = 0; page_no < rqstp->rq_resused; page_no++) {
ctxt->pages[page_no+1] = rqstp->rq_respages[page_no];
ctxt->count++;
rqstp->rq_respages[page_no] = NULL;
}
BUG_ON(sge_no > rdma->sc_max_sge);
memset(&send_wr, 0, sizeof send_wr);
ctxt->wr_op = IB_WR_SEND;
send_wr.wr_id = (unsigned long)ctxt;
send_wr.sg_list = ctxt->sge;
send_wr.num_sge = sge_no;
send_wr.opcode = IB_WR_SEND;
send_wr.send_flags = IB_SEND_SIGNALED;
ret = svc_rdma_send(rdma, &send_wr);
if (ret)
svc_rdma_put_context(ctxt, 1);
return ret;
}
void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
{
}
/*
* Return the start of an xdr buffer.
*/
static void *xdr_start(struct xdr_buf *xdr)
{
return xdr->head[0].iov_base -
(xdr->len -
xdr->page_len -
xdr->tail[0].iov_len -
xdr->head[0].iov_len);
}
int svc_rdma_sendto(struct svc_rqst *rqstp)
{
struct svc_xprt *xprt = rqstp->rq_xprt;
struct svcxprt_rdma *rdma =
container_of(xprt, struct svcxprt_rdma, sc_xprt);
struct rpcrdma_msg *rdma_argp;
struct rpcrdma_msg *rdma_resp;
struct rpcrdma_write_array *reply_ary;
enum rpcrdma_proc reply_type;
int ret;
int inline_bytes;
struct ib_sge *sge;
int sge_count = 0;
struct page *res_page;
struct svc_rdma_op_ctxt *ctxt;
dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
/* Get the RDMA request header. */
rdma_argp = xdr_start(&rqstp->rq_arg);
/* Build an SGE for the XDR */
ctxt = svc_rdma_get_context(rdma);
ctxt->direction = DMA_TO_DEVICE;
sge = xdr_to_sge(rdma, &rqstp->rq_res, ctxt->sge, &sge_count);
inline_bytes = rqstp->rq_res.len;
/* Create the RDMA response header */
res_page = svc_rdma_get_page();
rdma_resp = page_address(res_page);
reply_ary = svc_rdma_get_reply_array(rdma_argp);
if (reply_ary)
reply_type = RDMA_NOMSG;
else
reply_type = RDMA_MSG;
svc_rdma_xdr_encode_reply_header(rdma, rdma_argp,
rdma_resp, reply_type);
/* Send any write-chunk data and build resp write-list */
ret = send_write_chunks(rdma, rdma_argp, rdma_resp,
rqstp, sge, sge_count);
if (ret < 0) {
printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
ret);
goto error;
}
inline_bytes -= ret;
/* Send any reply-list data and update resp reply-list */
ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
rqstp, sge, sge_count);
if (ret < 0) {
printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
ret);
goto error;
}
inline_bytes -= ret;
ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, sge_count,
inline_bytes);
dprintk("svcrdma: send_reply returns %d\n", ret);
return ret;
error:
svc_rdma_put_context(ctxt, 0);
put_page(res_page);
return ret;
}
