/*
* 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.
*
* The max SGE we need is the length of the XDR / pagesize + one for
* head + one for tail + one for RPCRDMA header. Since RPCSVC_MAXPAGES
* reserves a page for both the request and the reply header, and this
* array is only concerned with the reply we are assured that we have
* on extra page for the RPCRMDA header.
*/
int fast_reg_xdr(struct svcxprt_rdma *xprt,
struct xdr_buf *xdr,
struct svc_rdma_req_map *vec)
{
int sge_no;
u32 sge_bytes;
u32 page_bytes;
u32 page_off;
int page_no = 0;
u8 *frva;
struct svc_rdma_fastreg_mr *frmr;
frmr = svc_rdma_get_frmr(xprt);
if (IS_ERR(frmr))
return -ENOMEM;
vec->frmr = frmr;
/* Skip the RPCRDMA header */
sge_no = 1;
/* Map the head. */
frva = (void *)((unsigned long)(xdr->head[0].iov_base) & PAGE_MASK);
vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
vec->count = 2;
sge_no++;
/* Build the FRMR */
frmr->kva = frva;
frmr->direction = DMA_TO_DEVICE;
frmr->access_flags = 0;
frmr->map_len = PAGE_SIZE;
frmr->page_list_len = 1;
frmr->page_list->page_list[page_no] =
ib_dma_map_single(xprt->sc_cm_id->device,
(void *)xdr->head[0].iov_base,
PAGE_SIZE, DMA_TO_DEVICE);
if (ib_dma_mapping_error(xprt->sc_cm_id->device,
frmr->page_list->page_list[page_no]))
goto fatal_err;
atomic_inc(&xprt->sc_dma_used);
page_off = xdr->page_base;
page_bytes = xdr->page_len + page_off;
if (!page_bytes)
goto encode_tail;
/* Map the pages */
vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
vec->sge[sge_no].iov_len = page_bytes;
sge_no++;
while (page_bytes) {
struct page *page;
page = xdr->pages[page_no++];
sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
page_bytes -= sge_bytes;
frmr->page_list->page_list[page_no] =
ib_dma_map_page(xprt->sc_cm_id->device, page, 0,
PAGE_SIZE, DMA_TO_DEVICE);
if (ib_dma_mapping_error(xprt->sc_cm_id->device,
frmr->page_list->page_list[page_no]))
goto fatal_err;
atomic_inc(&xprt->sc_dma_used);
page_off = 0; /* reset for next time through loop */
frmr->map_len += PAGE_SIZE;
frmr->page_list_len++;
}
vec->count++;
encode_tail:
/* Map tail */
if (0 == xdr->tail[0].iov_len)
goto done;
vec->count++;
vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
if (((unsigned long)xdr->tail[0].iov_base & PAGE_MASK) ==
((unsigned long)xdr->head[0].iov_base & PAGE_MASK)) {
/*
* If head and tail use the same page, we don't need
* to map it again.
*/
vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
} else {
void *va;
/* Map another page for the tail */
page_off = (unsigned long)xdr->tail[0].iov_base & ~PAGE_MASK;
va = (void *)((unsigned long)xdr->tail[0].iov_base & PAGE_MASK);
vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
frmr->page_list->page_list[page_no] =
ib_dma_map_single(xprt->sc_cm_id->device, va, PAGE_SIZE,
DMA_TO_DEVICE);
if (ib_dma_mapping_error(xprt->sc_cm_id->device,
frmr->page_list->page_list[page_no]))
goto fatal_err;
atomic_inc(&xprt->sc_dma_used);
frmr->map_len += PAGE_SIZE;
frmr->page_list_len++;
}
done:
if (svc_rdma_fastreg(xprt, frmr))
goto fatal_err;
return 0;
fatal_err:
printk("svcrdma: Error fast registering memory for xprt %p\n", xprt);
svc_rdma_put_frmr(xprt, frmr);
return -EIO;
}
static int map_xdr(struct svcxprt_rdma *xprt,
struct xdr_buf *xdr,
struct svc_rdma_req_map *vec)
{
int sge_max = (xdr->len+PAGE_SIZE-1) / PAGE_SIZE + 3;
int sge_no;
u32 sge_bytes;
u32 page_bytes;
u32 page_off;
int page_no;
BUG_ON(xdr->len !=
(xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len));
if (xprt->sc_frmr_pg_list_len)
return fast_reg_xdr(xprt, xdr, vec);
/* Skip the first sge, this is for the RPCRDMA header */
sge_no = 1;
/* Head SGE */
vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
sge_no++;
/* pages SGE */
page_no = 0;
page_bytes = xdr->page_len;
page_off = xdr->page_base;
while (page_bytes) {
vec->sge[sge_no].iov_base =
page_address(xdr->pages[page_no]) + page_off;
sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
page_bytes -= sge_bytes;
vec->sge[sge_no].iov_len = sge_bytes;
sge_no++;
page_no++;
page_off = 0; /* reset for next time through loop */
}
/* Tail SGE */
if (xdr->tail[0].iov_len) {
vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
sge_no++;
}
BUG_ON(sge_no > sge_max);
vec->count = sge_no;
return 0;
}
/* Assumptions:
* - We are using FRMR
* - or -
* - 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 svc_rdma_req_map *vec)
{
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;
BUG_ON(vec->count > RPCSVC_MAXPAGES);
dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
"write_len=%d, vec->sge=%p, vec->count=%lu\n",
rmr, (unsigned long long)to, xdr_off,
write_len, vec->sge, vec->count);
ctxt = svc_rdma_get_context(xprt);
ctxt->direction = DMA_TO_DEVICE;
sge = ctxt->sge;
/* Find the SGE associated with xdr_off */
for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count;
xdr_sge_no++) {
if (vec->sge[xdr_sge_no].iov_len > bc)
break;
bc -= vec->sge[xdr_sge_no].iov_len;
}
sge_off = bc;
bc = write_len;
sge_no = 0;
/* Copy the remaining SGE */
while (bc != 0) {
sge_bytes = min_t(size_t,
bc, vec->sge[xdr_sge_no].iov_len-sge_off);
sge[sge_no].length = sge_bytes;
if (!vec->frmr) {
sge[sge_no].addr =
ib_dma_map_single(xprt->sc_cm_id->device,
(void *)
vec->sge[xdr_sge_no].iov_base + sge_off,
sge_bytes, DMA_TO_DEVICE);
if (ib_dma_mapping_error(xprt->sc_cm_id->device,
sge[sge_no].addr))
goto err;
atomic_inc(&xprt->sc_dma_used);
sge[sge_no].lkey = xprt->sc_dma_lkey;
} else {
sge[sge_no].addr = (unsigned long)
vec->sge[xdr_sge_no].iov_base + sge_off;
sge[sge_no].lkey = vec->frmr->mr->lkey;
}
ctxt->count++;
ctxt->frmr = vec->frmr;
sge_off = 0;
sge_no++;
xdr_sge_no++;
BUG_ON(xdr_sge_no > vec->count);
bc -= sge_bytes;
}
/* 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))
goto err;
return 0;
err:
svc_rdma_put_context(ctxt, 0);
/* Fatal error, close transport */
return -EIO;
}
static int send_write_chunks(struct svcxprt_rdma *xprt,
struct rpcrdma_msg *rdma_argp,
struct rpcrdma_msg *rdma_resp,
struct svc_rqst *rqstp,
struct svc_rdma_req_map *vec)
{
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];
if (vec->frmr)
max_write = vec->frmr->map_len;
else
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,
vec);
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 svc_rdma_req_map *vec)
{
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];
if (vec->frmr)
max_write = vec->frmr->map_len;
else
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,
vec);
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,
struct svc_rdma_req_map *vec,
int byte_count)
{
struct ib_send_wr send_wr;
struct ib_send_wr inv_wr;
int sge_no;
int sge_bytes;
int page_no;
int ret;
/* Post a recv buffer to handle another request. */
ret = svc_rdma_post_recv(rdma);
if (ret) {
printk(KERN_INFO
"svcrdma: could not post a receive buffer, err=%d."
"Closing transport %p.\n", ret, rdma);
set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
svc_rdma_put_context(ctxt, 0);
return -ENOTCONN;
}
/* Prepare the context */
ctxt->pages[0] = page;
ctxt->count = 1;
ctxt->frmr = vec->frmr;
if (vec->frmr)
set_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
else
clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
/* 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);
if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr))
goto err;
atomic_inc(&rdma->sc_dma_used);
ctxt->direction = DMA_TO_DEVICE;
ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
ctxt->sge[0].lkey = rdma->sc_dma_lkey;
/* Determine how many of our SGE are to be transmitted */
for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) {
sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count);
byte_count -= sge_bytes;
if (!vec->frmr) {
ctxt->sge[sge_no].addr =
ib_dma_map_single(rdma->sc_cm_id->device,
vec->sge[sge_no].iov_base,
sge_bytes, DMA_TO_DEVICE);
if (ib_dma_mapping_error(rdma->sc_cm_id->device,
ctxt->sge[sge_no].addr))
goto err;
atomic_inc(&rdma->sc_dma_used);
ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey;
} else {
ctxt->sge[sge_no].addr = (unsigned long)
vec->sge[sge_no].iov_base;
ctxt->sge[sge_no].lkey = vec->frmr->mr->lkey;
}
ctxt->sge[sge_no].length = 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;
/*
* If there are more pages than SGE, terminate SGE
* list so that svc_rdma_unmap_dma doesn't attempt to
* unmap garbage.
*/
if (page_no+1 >= sge_no)
ctxt->sge[page_no+1].length = 0;
}
BUG_ON(sge_no > rdma->sc_max_sge);
BUG_ON(sge_no > ctxt->count);
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;
if (vec->frmr) {
/* Prepare INVALIDATE WR */
memset(&inv_wr, 0, sizeof inv_wr);
inv_wr.opcode = IB_WR_LOCAL_INV;
inv_wr.send_flags = IB_SEND_SIGNALED;
inv_wr.ex.invalidate_rkey =
vec->frmr->mr->lkey;
send_wr.next = &inv_wr;
}
ret = svc_rdma_send(rdma, &send_wr);
if (ret)
goto err;
return 0;
err:
svc_rdma_put_frmr(rdma, vec->frmr);
svc_rdma_put_context(ctxt, 1);
return -EIO;
}
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 page *res_page;
struct svc_rdma_op_ctxt *ctxt;
struct svc_rdma_req_map *vec;
dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
/* Get the RDMA request header. */
rdma_argp = xdr_start(&rqstp->rq_arg);
/* Build an req vec for the XDR */
ctxt = svc_rdma_get_context(rdma);
ctxt->direction = DMA_TO_DEVICE;
vec = svc_rdma_get_req_map();
ret = map_xdr(rdma, &rqstp->rq_res, vec);
if (ret)
goto err0;
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, vec);
if (ret < 0) {
printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
ret);
goto err1;
}
inline_bytes -= ret;
/* Send any reply-list data and update resp reply-list */
ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
rqstp, vec);
if (ret < 0) {
printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
ret);
goto err1;
}
inline_bytes -= ret;
ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec,
inline_bytes);
svc_rdma_put_req_map(vec);
dprintk("svcrdma: send_reply returns %d\n", ret);
return ret;
err1:
put_page(res_page);
err0:
svc_rdma_put_req_map(vec);
svc_rdma_put_context(ctxt, 0);
return ret;
}
