Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh64-2.6
[linux-2.6] / net / sunrpc / xprtrdma / rpc_rdma.c
1 /*
2  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the BSD-type
8  * license below:
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  *      Redistributions of source code must retain the above copyright
15  *      notice, this list of conditions and the following disclaimer.
16  *
17  *      Redistributions in binary form must reproduce the above
18  *      copyright notice, this list of conditions and the following
19  *      disclaimer in the documentation and/or other materials provided
20  *      with the distribution.
21  *
22  *      Neither the name of the Network Appliance, Inc. nor the names of
23  *      its contributors may be used to endorse or promote products
24  *      derived from this software without specific prior written
25  *      permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39
40 /*
41  * rpc_rdma.c
42  *
43  * This file contains the guts of the RPC RDMA protocol, and
44  * does marshaling/unmarshaling, etc. It is also where interfacing
45  * to the Linux RPC framework lives.
46  */
47
48 #include "xprt_rdma.h"
49
50 #include <linux/highmem.h>
51
52 #ifdef RPC_DEBUG
53 # define RPCDBG_FACILITY        RPCDBG_TRANS
54 #endif
55
56 enum rpcrdma_chunktype {
57         rpcrdma_noch = 0,
58         rpcrdma_readch,
59         rpcrdma_areadch,
60         rpcrdma_writech,
61         rpcrdma_replych
62 };
63
64 #ifdef RPC_DEBUG
65 static const char transfertypes[][12] = {
66         "pure inline",  /* no chunks */
67         " read chunk",  /* some argument via rdma read */
68         "*read chunk",  /* entire request via rdma read */
69         "write chunk",  /* some result via rdma write */
70         "reply chunk"   /* entire reply via rdma write */
71 };
72 #endif
73
74 /*
75  * Chunk assembly from upper layer xdr_buf.
76  *
77  * Prepare the passed-in xdr_buf into representation as RPC/RDMA chunk
78  * elements. Segments are then coalesced when registered, if possible
79  * within the selected memreg mode.
80  *
81  * Note, this routine is never called if the connection's memory
82  * registration strategy is 0 (bounce buffers).
83  */
84
85 static int
86 rpcrdma_convert_iovs(struct xdr_buf *xdrbuf, int pos,
87         enum rpcrdma_chunktype type, struct rpcrdma_mr_seg *seg, int nsegs)
88 {
89         int len, n = 0, p;
90
91         if (pos == 0 && xdrbuf->head[0].iov_len) {
92                 seg[n].mr_page = NULL;
93                 seg[n].mr_offset = xdrbuf->head[0].iov_base;
94                 seg[n].mr_len = xdrbuf->head[0].iov_len;
95                 pos += xdrbuf->head[0].iov_len;
96                 ++n;
97         }
98
99         if (xdrbuf->page_len && (xdrbuf->pages[0] != NULL)) {
100                 if (n == nsegs)
101                         return 0;
102                 seg[n].mr_page = xdrbuf->pages[0];
103                 seg[n].mr_offset = (void *)(unsigned long) xdrbuf->page_base;
104                 seg[n].mr_len = min_t(u32,
105                         PAGE_SIZE - xdrbuf->page_base, xdrbuf->page_len);
106                 len = xdrbuf->page_len - seg[n].mr_len;
107                 pos += len;
108                 ++n;
109                 p = 1;
110                 while (len > 0) {
111                         if (n == nsegs)
112                                 return 0;
113                         seg[n].mr_page = xdrbuf->pages[p];
114                         seg[n].mr_offset = NULL;
115                         seg[n].mr_len = min_t(u32, PAGE_SIZE, len);
116                         len -= seg[n].mr_len;
117                         ++n;
118                         ++p;
119                 }
120         }
121
122         if (pos < xdrbuf->len && xdrbuf->tail[0].iov_len) {
123                 if (n == nsegs)
124                         return 0;
125                 seg[n].mr_page = NULL;
126                 seg[n].mr_offset = xdrbuf->tail[0].iov_base;
127                 seg[n].mr_len = xdrbuf->tail[0].iov_len;
128                 pos += xdrbuf->tail[0].iov_len;
129                 ++n;
130         }
131
132         if (pos < xdrbuf->len)
133                 dprintk("RPC:       %s: marshaled only %d of %d\n",
134                                 __func__, pos, xdrbuf->len);
135
136         return n;
137 }
138
139 /*
140  * Create read/write chunk lists, and reply chunks, for RDMA
141  *
142  *   Assume check against THRESHOLD has been done, and chunks are required.
143  *   Assume only encoding one list entry for read|write chunks. The NFSv3
144  *     protocol is simple enough to allow this as it only has a single "bulk
145  *     result" in each procedure - complicated NFSv4 COMPOUNDs are not. (The
146  *     RDMA/Sessions NFSv4 proposal addresses this for future v4 revs.)
147  *
148  * When used for a single reply chunk (which is a special write
149  * chunk used for the entire reply, rather than just the data), it
150  * is used primarily for READDIR and READLINK which would otherwise
151  * be severely size-limited by a small rdma inline read max. The server
152  * response will come back as an RDMA Write, followed by a message
153  * of type RDMA_NOMSG carrying the xid and length. As a result, reply
154  * chunks do not provide data alignment, however they do not require
155  * "fixup" (moving the response to the upper layer buffer) either.
156  *
157  * Encoding key for single-list chunks (HLOO = Handle32 Length32 Offset64):
158  *
159  *  Read chunklist (a linked list):
160  *   N elements, position P (same P for all chunks of same arg!):
161  *    1 - PHLOO - 1 - PHLOO - ... - 1 - PHLOO - 0
162  *
163  *  Write chunklist (a list of (one) counted array):
164  *   N elements:
165  *    1 - N - HLOO - HLOO - ... - HLOO - 0
166  *
167  *  Reply chunk (a counted array):
168  *   N elements:
169  *    1 - N - HLOO - HLOO - ... - HLOO
170  */
171
172 static unsigned int
173 rpcrdma_create_chunks(struct rpc_rqst *rqst, struct xdr_buf *target,
174                 struct rpcrdma_msg *headerp, enum rpcrdma_chunktype type)
175 {
176         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
177         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_task->tk_xprt);
178         int nsegs, nchunks = 0;
179         int pos;
180         struct rpcrdma_mr_seg *seg = req->rl_segments;
181         struct rpcrdma_read_chunk *cur_rchunk = NULL;
182         struct rpcrdma_write_array *warray = NULL;
183         struct rpcrdma_write_chunk *cur_wchunk = NULL;
184         __be32 *iptr = headerp->rm_body.rm_chunks;
185
186         if (type == rpcrdma_readch || type == rpcrdma_areadch) {
187                 /* a read chunk - server will RDMA Read our memory */
188                 cur_rchunk = (struct rpcrdma_read_chunk *) iptr;
189         } else {
190                 /* a write or reply chunk - server will RDMA Write our memory */
191                 *iptr++ = xdr_zero;     /* encode a NULL read chunk list */
192                 if (type == rpcrdma_replych)
193                         *iptr++ = xdr_zero;     /* a NULL write chunk list */
194                 warray = (struct rpcrdma_write_array *) iptr;
195                 cur_wchunk = (struct rpcrdma_write_chunk *) (warray + 1);
196         }
197
198         if (type == rpcrdma_replych || type == rpcrdma_areadch)
199                 pos = 0;
200         else
201                 pos = target->head[0].iov_len;
202
203         nsegs = rpcrdma_convert_iovs(target, pos, type, seg, RPCRDMA_MAX_SEGS);
204         if (nsegs == 0)
205                 return 0;
206
207         do {
208                 /* bind/register the memory, then build chunk from result. */
209                 int n = rpcrdma_register_external(seg, nsegs,
210                                                 cur_wchunk != NULL, r_xprt);
211                 if (n <= 0)
212                         goto out;
213                 if (cur_rchunk) {       /* read */
214                         cur_rchunk->rc_discrim = xdr_one;
215                         /* all read chunks have the same "position" */
216                         cur_rchunk->rc_position = htonl(pos);
217                         cur_rchunk->rc_target.rs_handle = htonl(seg->mr_rkey);
218                         cur_rchunk->rc_target.rs_length = htonl(seg->mr_len);
219                         xdr_encode_hyper(
220                                         (__be32 *)&cur_rchunk->rc_target.rs_offset,
221                                         seg->mr_base);
222                         dprintk("RPC:       %s: read chunk "
223                                 "elem %d@0x%llx:0x%x pos %d (%s)\n", __func__,
224                                 seg->mr_len, (unsigned long long)seg->mr_base,
225                                 seg->mr_rkey, pos, n < nsegs ? "more" : "last");
226                         cur_rchunk++;
227                         r_xprt->rx_stats.read_chunk_count++;
228                 } else {                /* write/reply */
229                         cur_wchunk->wc_target.rs_handle = htonl(seg->mr_rkey);
230                         cur_wchunk->wc_target.rs_length = htonl(seg->mr_len);
231                         xdr_encode_hyper(
232                                         (__be32 *)&cur_wchunk->wc_target.rs_offset,
233                                         seg->mr_base);
234                         dprintk("RPC:       %s: %s chunk "
235                                 "elem %d@0x%llx:0x%x (%s)\n", __func__,
236                                 (type == rpcrdma_replych) ? "reply" : "write",
237                                 seg->mr_len, (unsigned long long)seg->mr_base,
238                                 seg->mr_rkey, n < nsegs ? "more" : "last");
239                         cur_wchunk++;
240                         if (type == rpcrdma_replych)
241                                 r_xprt->rx_stats.reply_chunk_count++;
242                         else
243                                 r_xprt->rx_stats.write_chunk_count++;
244                         r_xprt->rx_stats.total_rdma_request += seg->mr_len;
245                 }
246                 nchunks++;
247                 seg   += n;
248                 nsegs -= n;
249         } while (nsegs);
250
251         /* success. all failures return above */
252         req->rl_nchunks = nchunks;
253
254         BUG_ON(nchunks == 0);
255
256         /*
257          * finish off header. If write, marshal discrim and nchunks.
258          */
259         if (cur_rchunk) {
260                 iptr = (__be32 *) cur_rchunk;
261                 *iptr++ = xdr_zero;     /* finish the read chunk list */
262                 *iptr++ = xdr_zero;     /* encode a NULL write chunk list */
263                 *iptr++ = xdr_zero;     /* encode a NULL reply chunk */
264         } else {
265                 warray->wc_discrim = xdr_one;
266                 warray->wc_nchunks = htonl(nchunks);
267                 iptr = (__be32 *) cur_wchunk;
268                 if (type == rpcrdma_writech) {
269                         *iptr++ = xdr_zero; /* finish the write chunk list */
270                         *iptr++ = xdr_zero; /* encode a NULL reply chunk */
271                 }
272         }
273
274         /*
275          * Return header size.
276          */
277         return (unsigned char *)iptr - (unsigned char *)headerp;
278
279 out:
280         for (pos = 0; nchunks--;)
281                 pos += rpcrdma_deregister_external(
282                                 &req->rl_segments[pos], r_xprt, NULL);
283         return 0;
284 }
285
286 /*
287  * Copy write data inline.
288  * This function is used for "small" requests. Data which is passed
289  * to RPC via iovecs (or page list) is copied directly into the
290  * pre-registered memory buffer for this request. For small amounts
291  * of data, this is efficient. The cutoff value is tunable.
292  */
293 static int
294 rpcrdma_inline_pullup(struct rpc_rqst *rqst, int pad)
295 {
296         int i, npages, curlen;
297         int copy_len;
298         unsigned char *srcp, *destp;
299         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
300
301         destp = rqst->rq_svec[0].iov_base;
302         curlen = rqst->rq_svec[0].iov_len;
303         destp += curlen;
304         /*
305          * Do optional padding where it makes sense. Alignment of write
306          * payload can help the server, if our setting is accurate.
307          */
308         pad -= (curlen + 36/*sizeof(struct rpcrdma_msg_padded)*/);
309         if (pad < 0 || rqst->rq_slen - curlen < RPCRDMA_INLINE_PAD_THRESH)
310                 pad = 0;        /* don't pad this request */
311
312         dprintk("RPC:       %s: pad %d destp 0x%p len %d hdrlen %d\n",
313                 __func__, pad, destp, rqst->rq_slen, curlen);
314
315         copy_len = rqst->rq_snd_buf.page_len;
316         r_xprt->rx_stats.pullup_copy_count += copy_len;
317         npages = PAGE_ALIGN(rqst->rq_snd_buf.page_base+copy_len) >> PAGE_SHIFT;
318         for (i = 0; copy_len && i < npages; i++) {
319                 if (i == 0)
320                         curlen = PAGE_SIZE - rqst->rq_snd_buf.page_base;
321                 else
322                         curlen = PAGE_SIZE;
323                 if (curlen > copy_len)
324                         curlen = copy_len;
325                 dprintk("RPC:       %s: page %d destp 0x%p len %d curlen %d\n",
326                         __func__, i, destp, copy_len, curlen);
327                 srcp = kmap_atomic(rqst->rq_snd_buf.pages[i],
328                                         KM_SKB_SUNRPC_DATA);
329                 if (i == 0)
330                         memcpy(destp, srcp+rqst->rq_snd_buf.page_base, curlen);
331                 else
332                         memcpy(destp, srcp, curlen);
333                 kunmap_atomic(srcp, KM_SKB_SUNRPC_DATA);
334                 rqst->rq_svec[0].iov_len += curlen;
335                 destp += curlen;
336                 copy_len -= curlen;
337         }
338         if (rqst->rq_snd_buf.tail[0].iov_len) {
339                 curlen = rqst->rq_snd_buf.tail[0].iov_len;
340                 if (destp != rqst->rq_snd_buf.tail[0].iov_base) {
341                         memcpy(destp,
342                                 rqst->rq_snd_buf.tail[0].iov_base, curlen);
343                         r_xprt->rx_stats.pullup_copy_count += curlen;
344                 }
345                 dprintk("RPC:       %s: tail destp 0x%p len %d curlen %d\n",
346                         __func__, destp, copy_len, curlen);
347                 rqst->rq_svec[0].iov_len += curlen;
348         }
349         /* header now contains entire send message */
350         return pad;
351 }
352
353 /*
354  * Marshal a request: the primary job of this routine is to choose
355  * the transfer modes. See comments below.
356  *
357  * Uses multiple RDMA IOVs for a request:
358  *  [0] -- RPC RDMA header, which uses memory from the *start* of the
359  *         preregistered buffer that already holds the RPC data in
360  *         its middle.
361  *  [1] -- the RPC header/data, marshaled by RPC and the NFS protocol.
362  *  [2] -- optional padding.
363  *  [3] -- if padded, header only in [1] and data here.
364  */
365
366 int
367 rpcrdma_marshal_req(struct rpc_rqst *rqst)
368 {
369         struct rpc_xprt *xprt = rqst->rq_task->tk_xprt;
370         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
371         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
372         char *base;
373         size_t hdrlen, rpclen, padlen;
374         enum rpcrdma_chunktype rtype, wtype;
375         struct rpcrdma_msg *headerp;
376
377         /*
378          * rpclen gets amount of data in first buffer, which is the
379          * pre-registered buffer.
380          */
381         base = rqst->rq_svec[0].iov_base;
382         rpclen = rqst->rq_svec[0].iov_len;
383
384         /* build RDMA header in private area at front */
385         headerp = (struct rpcrdma_msg *) req->rl_base;
386         /* don't htonl XID, it's already done in request */
387         headerp->rm_xid = rqst->rq_xid;
388         headerp->rm_vers = xdr_one;
389         headerp->rm_credit = htonl(r_xprt->rx_buf.rb_max_requests);
390         headerp->rm_type = __constant_htonl(RDMA_MSG);
391
392         /*
393          * Chunks needed for results?
394          *
395          * o If the expected result is under the inline threshold, all ops
396          *   return as inline (but see later).
397          * o Large non-read ops return as a single reply chunk.
398          * o Large read ops return data as write chunk(s), header as inline.
399          *
400          * Note: the NFS code sending down multiple result segments implies
401          * the op is one of read, readdir[plus], readlink or NFSv4 getacl.
402          */
403
404         /*
405          * This code can handle read chunks, write chunks OR reply
406          * chunks -- only one type. If the request is too big to fit
407          * inline, then we will choose read chunks. If the request is
408          * a READ, then use write chunks to separate the file data
409          * into pages; otherwise use reply chunks.
410          */
411         if (rqst->rq_rcv_buf.buflen <= RPCRDMA_INLINE_READ_THRESHOLD(rqst))
412                 wtype = rpcrdma_noch;
413         else if (rqst->rq_rcv_buf.page_len == 0)
414                 wtype = rpcrdma_replych;
415         else if (rqst->rq_rcv_buf.flags & XDRBUF_READ)
416                 wtype = rpcrdma_writech;
417         else
418                 wtype = rpcrdma_replych;
419
420         /*
421          * Chunks needed for arguments?
422          *
423          * o If the total request is under the inline threshold, all ops
424          *   are sent as inline.
425          * o Large non-write ops are sent with the entire message as a
426          *   single read chunk (protocol 0-position special case).
427          * o Large write ops transmit data as read chunk(s), header as
428          *   inline.
429          *
430          * Note: the NFS code sending down multiple argument segments
431          * implies the op is a write.
432          * TBD check NFSv4 setacl
433          */
434         if (rqst->rq_snd_buf.len <= RPCRDMA_INLINE_WRITE_THRESHOLD(rqst))
435                 rtype = rpcrdma_noch;
436         else if (rqst->rq_snd_buf.page_len == 0)
437                 rtype = rpcrdma_areadch;
438         else
439                 rtype = rpcrdma_readch;
440
441         /* The following simplification is not true forever */
442         if (rtype != rpcrdma_noch && wtype == rpcrdma_replych)
443                 wtype = rpcrdma_noch;
444         BUG_ON(rtype != rpcrdma_noch && wtype != rpcrdma_noch);
445
446         if (r_xprt->rx_ia.ri_memreg_strategy == RPCRDMA_BOUNCEBUFFERS &&
447             (rtype != rpcrdma_noch || wtype != rpcrdma_noch)) {
448                 /* forced to "pure inline"? */
449                 dprintk("RPC:       %s: too much data (%d/%d) for inline\n",
450                         __func__, rqst->rq_rcv_buf.len, rqst->rq_snd_buf.len);
451                 return -1;
452         }
453
454         hdrlen = 28; /*sizeof *headerp;*/
455         padlen = 0;
456
457         /*
458          * Pull up any extra send data into the preregistered buffer.
459          * When padding is in use and applies to the transfer, insert
460          * it and change the message type.
461          */
462         if (rtype == rpcrdma_noch) {
463
464                 padlen = rpcrdma_inline_pullup(rqst,
465                                                 RPCRDMA_INLINE_PAD_VALUE(rqst));
466
467                 if (padlen) {
468                         headerp->rm_type = __constant_htonl(RDMA_MSGP);
469                         headerp->rm_body.rm_padded.rm_align =
470                                 htonl(RPCRDMA_INLINE_PAD_VALUE(rqst));
471                         headerp->rm_body.rm_padded.rm_thresh =
472                                 __constant_htonl(RPCRDMA_INLINE_PAD_THRESH);
473                         headerp->rm_body.rm_padded.rm_pempty[0] = xdr_zero;
474                         headerp->rm_body.rm_padded.rm_pempty[1] = xdr_zero;
475                         headerp->rm_body.rm_padded.rm_pempty[2] = xdr_zero;
476                         hdrlen += 2 * sizeof(u32); /* extra words in padhdr */
477                         BUG_ON(wtype != rpcrdma_noch);
478
479                 } else {
480                         headerp->rm_body.rm_nochunks.rm_empty[0] = xdr_zero;
481                         headerp->rm_body.rm_nochunks.rm_empty[1] = xdr_zero;
482                         headerp->rm_body.rm_nochunks.rm_empty[2] = xdr_zero;
483                         /* new length after pullup */
484                         rpclen = rqst->rq_svec[0].iov_len;
485                         /*
486                          * Currently we try to not actually use read inline.
487                          * Reply chunks have the desirable property that
488                          * they land, packed, directly in the target buffers
489                          * without headers, so they require no fixup. The
490                          * additional RDMA Write op sends the same amount
491                          * of data, streams on-the-wire and adds no overhead
492                          * on receive. Therefore, we request a reply chunk
493                          * for non-writes wherever feasible and efficient.
494                          */
495                         if (wtype == rpcrdma_noch &&
496                             r_xprt->rx_ia.ri_memreg_strategy > RPCRDMA_REGISTER)
497                                 wtype = rpcrdma_replych;
498                 }
499         }
500
501         /*
502          * Marshal chunks. This routine will return the header length
503          * consumed by marshaling.
504          */
505         if (rtype != rpcrdma_noch) {
506                 hdrlen = rpcrdma_create_chunks(rqst,
507                                         &rqst->rq_snd_buf, headerp, rtype);
508                 wtype = rtype;  /* simplify dprintk */
509
510         } else if (wtype != rpcrdma_noch) {
511                 hdrlen = rpcrdma_create_chunks(rqst,
512                                         &rqst->rq_rcv_buf, headerp, wtype);
513         }
514
515         if (hdrlen == 0)
516                 return -1;
517
518         dprintk("RPC:       %s: %s: hdrlen %zd rpclen %zd padlen %zd\n"
519                 "                   headerp 0x%p base 0x%p lkey 0x%x\n",
520                 __func__, transfertypes[wtype], hdrlen, rpclen, padlen,
521                 headerp, base, req->rl_iov.lkey);
522
523         /*
524          * initialize send_iov's - normally only two: rdma chunk header and
525          * single preregistered RPC header buffer, but if padding is present,
526          * then use a preregistered (and zeroed) pad buffer between the RPC
527          * header and any write data. In all non-rdma cases, any following
528          * data has been copied into the RPC header buffer.
529          */
530         req->rl_send_iov[0].addr = req->rl_iov.addr;
531         req->rl_send_iov[0].length = hdrlen;
532         req->rl_send_iov[0].lkey = req->rl_iov.lkey;
533
534         req->rl_send_iov[1].addr = req->rl_iov.addr + (base - req->rl_base);
535         req->rl_send_iov[1].length = rpclen;
536         req->rl_send_iov[1].lkey = req->rl_iov.lkey;
537
538         req->rl_niovs = 2;
539
540         if (padlen) {
541                 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
542
543                 req->rl_send_iov[2].addr = ep->rep_pad.addr;
544                 req->rl_send_iov[2].length = padlen;
545                 req->rl_send_iov[2].lkey = ep->rep_pad.lkey;
546
547                 req->rl_send_iov[3].addr = req->rl_send_iov[1].addr + rpclen;
548                 req->rl_send_iov[3].length = rqst->rq_slen - rpclen;
549                 req->rl_send_iov[3].lkey = req->rl_iov.lkey;
550
551                 req->rl_niovs = 4;
552         }
553
554         return 0;
555 }
556
557 /*
558  * Chase down a received write or reply chunklist to get length
559  * RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
560  */
561 static int
562 rpcrdma_count_chunks(struct rpcrdma_rep *rep, int max, int wrchunk, __be32 **iptrp)
563 {
564         unsigned int i, total_len;
565         struct rpcrdma_write_chunk *cur_wchunk;
566
567         i = ntohl(**iptrp);     /* get array count */
568         if (i > max)
569                 return -1;
570         cur_wchunk = (struct rpcrdma_write_chunk *) (*iptrp + 1);
571         total_len = 0;
572         while (i--) {
573                 struct rpcrdma_segment *seg = &cur_wchunk->wc_target;
574                 ifdebug(FACILITY) {
575                         u64 off;
576                         xdr_decode_hyper((__be32 *)&seg->rs_offset, &off);
577                         dprintk("RPC:       %s: chunk %d@0x%llx:0x%x\n",
578                                 __func__,
579                                 ntohl(seg->rs_length),
580                                 (unsigned long long)off,
581                                 ntohl(seg->rs_handle));
582                 }
583                 total_len += ntohl(seg->rs_length);
584                 ++cur_wchunk;
585         }
586         /* check and adjust for properly terminated write chunk */
587         if (wrchunk) {
588                 __be32 *w = (__be32 *) cur_wchunk;
589                 if (*w++ != xdr_zero)
590                         return -1;
591                 cur_wchunk = (struct rpcrdma_write_chunk *) w;
592         }
593         if ((char *) cur_wchunk > rep->rr_base + rep->rr_len)
594                 return -1;
595
596         *iptrp = (__be32 *) cur_wchunk;
597         return total_len;
598 }
599
600 /*
601  * Scatter inline received data back into provided iov's.
602  */
603 static void
604 rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len)
605 {
606         int i, npages, curlen, olen;
607         char *destp;
608
609         curlen = rqst->rq_rcv_buf.head[0].iov_len;
610         if (curlen > copy_len) {        /* write chunk header fixup */
611                 curlen = copy_len;
612                 rqst->rq_rcv_buf.head[0].iov_len = curlen;
613         }
614
615         dprintk("RPC:       %s: srcp 0x%p len %d hdrlen %d\n",
616                 __func__, srcp, copy_len, curlen);
617
618         /* Shift pointer for first receive segment only */
619         rqst->rq_rcv_buf.head[0].iov_base = srcp;
620         srcp += curlen;
621         copy_len -= curlen;
622
623         olen = copy_len;
624         i = 0;
625         rpcx_to_rdmax(rqst->rq_xprt)->rx_stats.fixup_copy_count += olen;
626         if (copy_len && rqst->rq_rcv_buf.page_len) {
627                 npages = PAGE_ALIGN(rqst->rq_rcv_buf.page_base +
628                         rqst->rq_rcv_buf.page_len) >> PAGE_SHIFT;
629                 for (; i < npages; i++) {
630                         if (i == 0)
631                                 curlen = PAGE_SIZE - rqst->rq_rcv_buf.page_base;
632                         else
633                                 curlen = PAGE_SIZE;
634                         if (curlen > copy_len)
635                                 curlen = copy_len;
636                         dprintk("RPC:       %s: page %d"
637                                 " srcp 0x%p len %d curlen %d\n",
638                                 __func__, i, srcp, copy_len, curlen);
639                         destp = kmap_atomic(rqst->rq_rcv_buf.pages[i],
640                                                 KM_SKB_SUNRPC_DATA);
641                         if (i == 0)
642                                 memcpy(destp + rqst->rq_rcv_buf.page_base,
643                                                 srcp, curlen);
644                         else
645                                 memcpy(destp, srcp, curlen);
646                         flush_dcache_page(rqst->rq_rcv_buf.pages[i]);
647                         kunmap_atomic(destp, KM_SKB_SUNRPC_DATA);
648                         srcp += curlen;
649                         copy_len -= curlen;
650                         if (copy_len == 0)
651                                 break;
652                 }
653                 rqst->rq_rcv_buf.page_len = olen - copy_len;
654         } else
655                 rqst->rq_rcv_buf.page_len = 0;
656
657         if (copy_len && rqst->rq_rcv_buf.tail[0].iov_len) {
658                 curlen = copy_len;
659                 if (curlen > rqst->rq_rcv_buf.tail[0].iov_len)
660                         curlen = rqst->rq_rcv_buf.tail[0].iov_len;
661                 if (rqst->rq_rcv_buf.tail[0].iov_base != srcp)
662                         memcpy(rqst->rq_rcv_buf.tail[0].iov_base, srcp, curlen);
663                 dprintk("RPC:       %s: tail srcp 0x%p len %d curlen %d\n",
664                         __func__, srcp, copy_len, curlen);
665                 rqst->rq_rcv_buf.tail[0].iov_len = curlen;
666                 copy_len -= curlen; ++i;
667         } else
668                 rqst->rq_rcv_buf.tail[0].iov_len = 0;
669
670         if (copy_len)
671                 dprintk("RPC:       %s: %d bytes in"
672                         " %d extra segments (%d lost)\n",
673                         __func__, olen, i, copy_len);
674
675         /* TBD avoid a warning from call_decode() */
676         rqst->rq_private_buf = rqst->rq_rcv_buf;
677 }
678
679 /*
680  * This function is called when an async event is posted to
681  * the connection which changes the connection state. All it
682  * does at this point is mark the connection up/down, the rpc
683  * timers do the rest.
684  */
685 void
686 rpcrdma_conn_func(struct rpcrdma_ep *ep)
687 {
688         struct rpc_xprt *xprt = ep->rep_xprt;
689
690         spin_lock_bh(&xprt->transport_lock);
691         if (ep->rep_connected > 0) {
692                 if (!xprt_test_and_set_connected(xprt))
693                         xprt_wake_pending_tasks(xprt, 0);
694         } else {
695                 if (xprt_test_and_clear_connected(xprt))
696                         xprt_wake_pending_tasks(xprt, ep->rep_connected);
697         }
698         spin_unlock_bh(&xprt->transport_lock);
699 }
700
701 /*
702  * This function is called when memory window unbind which we are waiting
703  * for completes. Just use rr_func (zeroed by upcall) to signal completion.
704  */
705 static void
706 rpcrdma_unbind_func(struct rpcrdma_rep *rep)
707 {
708         wake_up(&rep->rr_unbind);
709 }
710
711 /*
712  * Called as a tasklet to do req/reply match and complete a request
713  * Errors must result in the RPC task either being awakened, or
714  * allowed to timeout, to discover the errors at that time.
715  */
716 void
717 rpcrdma_reply_handler(struct rpcrdma_rep *rep)
718 {
719         struct rpcrdma_msg *headerp;
720         struct rpcrdma_req *req;
721         struct rpc_rqst *rqst;
722         struct rpc_xprt *xprt = rep->rr_xprt;
723         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
724         __be32 *iptr;
725         int i, rdmalen, status;
726
727         /* Check status. If bad, signal disconnect and return rep to pool */
728         if (rep->rr_len == ~0U) {
729                 rpcrdma_recv_buffer_put(rep);
730                 if (r_xprt->rx_ep.rep_connected == 1) {
731                         r_xprt->rx_ep.rep_connected = -EIO;
732                         rpcrdma_conn_func(&r_xprt->rx_ep);
733                 }
734                 return;
735         }
736         if (rep->rr_len < 28) {
737                 dprintk("RPC:       %s: short/invalid reply\n", __func__);
738                 goto repost;
739         }
740         headerp = (struct rpcrdma_msg *) rep->rr_base;
741         if (headerp->rm_vers != xdr_one) {
742                 dprintk("RPC:       %s: invalid version %d\n",
743                         __func__, ntohl(headerp->rm_vers));
744                 goto repost;
745         }
746
747         /* Get XID and try for a match. */
748         spin_lock(&xprt->transport_lock);
749         rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
750         if (rqst == NULL) {
751                 spin_unlock(&xprt->transport_lock);
752                 dprintk("RPC:       %s: reply 0x%p failed "
753                         "to match any request xid 0x%08x len %d\n",
754                         __func__, rep, headerp->rm_xid, rep->rr_len);
755 repost:
756                 r_xprt->rx_stats.bad_reply_count++;
757                 rep->rr_func = rpcrdma_reply_handler;
758                 if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, &r_xprt->rx_ep, rep))
759                         rpcrdma_recv_buffer_put(rep);
760
761                 return;
762         }
763
764         /* get request object */
765         req = rpcr_to_rdmar(rqst);
766
767         dprintk("RPC:       %s: reply 0x%p completes request 0x%p\n"
768                 "                   RPC request 0x%p xid 0x%08x\n",
769                         __func__, rep, req, rqst, headerp->rm_xid);
770
771         BUG_ON(!req || req->rl_reply);
772
773         /* from here on, the reply is no longer an orphan */
774         req->rl_reply = rep;
775
776         /* check for expected message types */
777         /* The order of some of these tests is important. */
778         switch (headerp->rm_type) {
779         case __constant_htonl(RDMA_MSG):
780                 /* never expect read chunks */
781                 /* never expect reply chunks (two ways to check) */
782                 /* never expect write chunks without having offered RDMA */
783                 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
784                     (headerp->rm_body.rm_chunks[1] == xdr_zero &&
785                      headerp->rm_body.rm_chunks[2] != xdr_zero) ||
786                     (headerp->rm_body.rm_chunks[1] != xdr_zero &&
787                      req->rl_nchunks == 0))
788                         goto badheader;
789                 if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
790                         /* count any expected write chunks in read reply */
791                         /* start at write chunk array count */
792                         iptr = &headerp->rm_body.rm_chunks[2];
793                         rdmalen = rpcrdma_count_chunks(rep,
794                                                 req->rl_nchunks, 1, &iptr);
795                         /* check for validity, and no reply chunk after */
796                         if (rdmalen < 0 || *iptr++ != xdr_zero)
797                                 goto badheader;
798                         rep->rr_len -=
799                             ((unsigned char *)iptr - (unsigned char *)headerp);
800                         status = rep->rr_len + rdmalen;
801                         r_xprt->rx_stats.total_rdma_reply += rdmalen;
802                 } else {
803                         /* else ordinary inline */
804                         iptr = (__be32 *)((unsigned char *)headerp + 28);
805                         rep->rr_len -= 28; /*sizeof *headerp;*/
806                         status = rep->rr_len;
807                 }
808                 /* Fix up the rpc results for upper layer */
809                 rpcrdma_inline_fixup(rqst, (char *)iptr, rep->rr_len);
810                 break;
811
812         case __constant_htonl(RDMA_NOMSG):
813                 /* never expect read or write chunks, always reply chunks */
814                 if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
815                     headerp->rm_body.rm_chunks[1] != xdr_zero ||
816                     headerp->rm_body.rm_chunks[2] != xdr_one ||
817                     req->rl_nchunks == 0)
818                         goto badheader;
819                 iptr = (__be32 *)((unsigned char *)headerp + 28);
820                 rdmalen = rpcrdma_count_chunks(rep, req->rl_nchunks, 0, &iptr);
821                 if (rdmalen < 0)
822                         goto badheader;
823                 r_xprt->rx_stats.total_rdma_reply += rdmalen;
824                 /* Reply chunk buffer already is the reply vector - no fixup. */
825                 status = rdmalen;
826                 break;
827
828 badheader:
829         default:
830                 dprintk("%s: invalid rpcrdma reply header (type %d):"
831                                 " chunks[012] == %d %d %d"
832                                 " expected chunks <= %d\n",
833                                 __func__, ntohl(headerp->rm_type),
834                                 headerp->rm_body.rm_chunks[0],
835                                 headerp->rm_body.rm_chunks[1],
836                                 headerp->rm_body.rm_chunks[2],
837                                 req->rl_nchunks);
838                 status = -EIO;
839                 r_xprt->rx_stats.bad_reply_count++;
840                 break;
841         }
842
843         /* If using mw bind, start the deregister process now. */
844         /* (Note: if mr_free(), cannot perform it here, in tasklet context) */
845         if (req->rl_nchunks) switch (r_xprt->rx_ia.ri_memreg_strategy) {
846         case RPCRDMA_MEMWINDOWS:
847                 for (i = 0; req->rl_nchunks-- > 1;)
848                         i += rpcrdma_deregister_external(
849                                 &req->rl_segments[i], r_xprt, NULL);
850                 /* Optionally wait (not here) for unbinds to complete */
851                 rep->rr_func = rpcrdma_unbind_func;
852                 (void) rpcrdma_deregister_external(&req->rl_segments[i],
853                                                    r_xprt, rep);
854                 break;
855         case RPCRDMA_MEMWINDOWS_ASYNC:
856                 for (i = 0; req->rl_nchunks--;)
857                         i += rpcrdma_deregister_external(&req->rl_segments[i],
858                                                          r_xprt, NULL);
859                 break;
860         default:
861                 break;
862         }
863
864         dprintk("RPC:       %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
865                         __func__, xprt, rqst, status);
866         xprt_complete_rqst(rqst->rq_task, status);
867         spin_unlock(&xprt->transport_lock);
868 }