blob: f27d2c82b036f207a06b3b54193e43eded88757f [file] [log] [blame]
Andy Grover6a0979d2009-02-24 15:30:33 +00001/*
2 * Copyright (c) 2006 Oracle. 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
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
34#include <linux/in.h>
35#include <linux/device.h>
36#include <linux/dmapool.h>
Manuel Zerpiescb0a6052011-06-16 02:09:57 +000037#include <linux/ratelimit.h>
Andy Grover6a0979d2009-02-24 15:30:33 +000038
39#include "rds.h"
Andy Grover6a0979d2009-02-24 15:30:33 +000040#include "ib.h"
41
Andy Grover9c030392010-01-12 14:43:06 -080042/*
43 * Convert IB-specific error message to RDS error message and call core
44 * completion handler.
45 */
46static void rds_ib_send_complete(struct rds_message *rm,
47 int wc_status,
48 void (*complete)(struct rds_message *rm, int status))
Andy Grover6a0979d2009-02-24 15:30:33 +000049{
50 int notify_status;
51
52 switch (wc_status) {
53 case IB_WC_WR_FLUSH_ERR:
54 return;
55
56 case IB_WC_SUCCESS:
57 notify_status = RDS_RDMA_SUCCESS;
58 break;
59
60 case IB_WC_REM_ACCESS_ERR:
61 notify_status = RDS_RDMA_REMOTE_ERROR;
62 break;
63
64 default:
65 notify_status = RDS_RDMA_OTHER_ERROR;
66 break;
67 }
Andy Grover9c030392010-01-12 14:43:06 -080068 complete(rm, notify_status);
Andy Grover6a0979d2009-02-24 15:30:33 +000069}
70
Andy Groverff3d7d32010-03-01 14:03:09 -080071static void rds_ib_send_unmap_data(struct rds_ib_connection *ic,
72 struct rm_data_op *op,
73 int wc_status)
Andy Grover6a0979d2009-02-24 15:30:33 +000074{
Andy Groverff3d7d32010-03-01 14:03:09 -080075 if (op->op_nents)
76 ib_dma_unmap_sg(ic->i_cm_id->device,
77 op->op_sg, op->op_nents,
78 DMA_TO_DEVICE);
79}
Andy Grover6a0979d2009-02-24 15:30:33 +000080
Andy Groverff3d7d32010-03-01 14:03:09 -080081static void rds_ib_send_unmap_rdma(struct rds_ib_connection *ic,
82 struct rm_rdma_op *op,
83 int wc_status)
84{
85 if (op->op_mapped) {
86 ib_dma_unmap_sg(ic->i_cm_id->device,
87 op->op_sg, op->op_nents,
88 op->op_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
89 op->op_mapped = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +000090 }
91
Andy Groverff3d7d32010-03-01 14:03:09 -080092 /* If the user asked for a completion notification on this
93 * message, we can implement three different semantics:
94 * 1. Notify when we received the ACK on the RDS message
95 * that was queued with the RDMA. This provides reliable
96 * notification of RDMA status at the expense of a one-way
97 * packet delay.
98 * 2. Notify when the IB stack gives us the completion event for
99 * the RDMA operation.
100 * 3. Notify when the IB stack gives us the completion event for
101 * the accompanying RDS messages.
102 * Here, we implement approach #3. To implement approach #2,
103 * we would need to take an event for the rdma WR. To implement #1,
104 * don't call rds_rdma_send_complete at all, and fall back to the notify
105 * handling in the ACK processing code.
106 *
107 * Note: There's no need to explicitly sync any RDMA buffers using
108 * ib_dma_sync_sg_for_cpu - the completion for the RDMA
109 * operation itself unmapped the RDMA buffers, which takes care
110 * of synching.
111 */
112 rds_ib_send_complete(container_of(op, struct rds_message, rdma),
113 wc_status, rds_rdma_send_complete);
Andy Grover15133f62010-01-12 14:33:38 -0800114
Andy Groverff3d7d32010-03-01 14:03:09 -0800115 if (op->op_write)
116 rds_stats_add(s_send_rdma_bytes, op->op_bytes);
117 else
118 rds_stats_add(s_recv_rdma_bytes, op->op_bytes);
119}
Andy Grover15133f62010-01-12 14:33:38 -0800120
Andy Groverff3d7d32010-03-01 14:03:09 -0800121static void rds_ib_send_unmap_atomic(struct rds_ib_connection *ic,
122 struct rm_atomic_op *op,
123 int wc_status)
124{
125 /* unmap atomic recvbuf */
126 if (op->op_mapped) {
127 ib_dma_unmap_sg(ic->i_cm_id->device, op->op_sg, 1,
128 DMA_FROM_DEVICE);
129 op->op_mapped = 0;
Andy Grover15133f62010-01-12 14:33:38 -0800130 }
131
Andy Groverff3d7d32010-03-01 14:03:09 -0800132 rds_ib_send_complete(container_of(op, struct rds_message, atomic),
133 wc_status, rds_atomic_send_complete);
Andy Grover6a0979d2009-02-24 15:30:33 +0000134
Andy Groverff3d7d32010-03-01 14:03:09 -0800135 if (op->op_type == RDS_ATOMIC_TYPE_CSWP)
Andy Grover51e2cba2010-03-29 17:47:30 -0700136 rds_ib_stats_inc(s_ib_atomic_cswp);
Andy Groverff3d7d32010-03-01 14:03:09 -0800137 else
Andy Grover51e2cba2010-03-29 17:47:30 -0700138 rds_ib_stats_inc(s_ib_atomic_fadd);
Andy Groverff3d7d32010-03-01 14:03:09 -0800139}
140
141/*
142 * Unmap the resources associated with a struct send_work.
143 *
144 * Returns the rm for no good reason other than it is unobtainable
145 * other than by switching on wr.opcode, currently, and the caller,
146 * the event handler, needs it.
147 */
148static struct rds_message *rds_ib_send_unmap_op(struct rds_ib_connection *ic,
149 struct rds_ib_send_work *send,
150 int wc_status)
151{
152 struct rds_message *rm = NULL;
153
154 /* In the error case, wc.opcode sometimes contains garbage */
155 switch (send->s_wr.opcode) {
156 case IB_WR_SEND:
157 if (send->s_op) {
158 rm = container_of(send->s_op, struct rds_message, data);
159 rds_ib_send_unmap_data(ic, send->s_op, wc_status);
160 }
161 break;
162 case IB_WR_RDMA_WRITE:
163 case IB_WR_RDMA_READ:
164 if (send->s_op) {
165 rm = container_of(send->s_op, struct rds_message, rdma);
166 rds_ib_send_unmap_rdma(ic, send->s_op, wc_status);
167 }
168 break;
169 case IB_WR_ATOMIC_FETCH_AND_ADD:
170 case IB_WR_ATOMIC_CMP_AND_SWP:
171 if (send->s_op) {
172 rm = container_of(send->s_op, struct rds_message, atomic);
173 rds_ib_send_unmap_atomic(ic, send->s_op, wc_status);
174 }
175 break;
176 default:
Manuel Zerpiescb0a6052011-06-16 02:09:57 +0000177 printk_ratelimited(KERN_NOTICE
Andy Groverff3d7d32010-03-01 14:03:09 -0800178 "RDS/IB: %s: unexpected opcode 0x%x in WR!\n",
179 __func__, send->s_wr.opcode);
180 break;
181 }
182
183 send->s_wr.opcode = 0xdead;
184
185 return rm;
Andy Grover6a0979d2009-02-24 15:30:33 +0000186}
187
188void rds_ib_send_init_ring(struct rds_ib_connection *ic)
189{
190 struct rds_ib_send_work *send;
191 u32 i;
192
193 for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) {
194 struct ib_sge *sge;
195
Andy Grover6a0979d2009-02-24 15:30:33 +0000196 send->s_op = NULL;
197
santosh.shilimkar@oracle.comdcfd0412016-03-01 15:20:45 -0800198 send->s_wr.wr_id = i;
Andy Grover6a0979d2009-02-24 15:30:33 +0000199 send->s_wr.sg_list = send->s_sge;
Andy Grover6a0979d2009-02-24 15:30:33 +0000200 send->s_wr.ex.imm_data = 0;
201
Andy Grover919ced42010-01-13 16:32:24 -0800202 sge = &send->s_sge[0];
Andy Grover6a0979d2009-02-24 15:30:33 +0000203 sge->addr = ic->i_send_hdrs_dma + (i * sizeof(struct rds_header));
204 sge->length = sizeof(struct rds_header);
Jason Gunthorpee5580242015-07-30 17:22:26 -0600205 sge->lkey = ic->i_pd->local_dma_lkey;
Andy Grover919ced42010-01-13 16:32:24 -0800206
Jason Gunthorpee5580242015-07-30 17:22:26 -0600207 send->s_sge[1].lkey = ic->i_pd->local_dma_lkey;
Andy Grover6a0979d2009-02-24 15:30:33 +0000208 }
209}
210
211void rds_ib_send_clear_ring(struct rds_ib_connection *ic)
212{
213 struct rds_ib_send_work *send;
214 u32 i;
215
216 for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) {
Andy Groverff3d7d32010-03-01 14:03:09 -0800217 if (send->s_op && send->s_wr.opcode != 0xdead)
218 rds_ib_send_unmap_op(ic, send, IB_WC_WR_FLUSH_ERR);
Andy Grover6a0979d2009-02-24 15:30:33 +0000219 }
220}
221
222/*
Zach Brownf0460112010-07-14 13:55:35 -0700223 * The only fast path caller always has a non-zero nr, so we don't
224 * bother testing nr before performing the atomic sub.
225 */
226static void rds_ib_sub_signaled(struct rds_ib_connection *ic, int nr)
227{
228 if ((atomic_sub_return(nr, &ic->i_signaled_sends) == 0) &&
229 waitqueue_active(&rds_ib_ring_empty_wait))
230 wake_up(&rds_ib_ring_empty_wait);
231 BUG_ON(atomic_read(&ic->i_signaled_sends) < 0);
232}
233
234/*
Andy Grover6a0979d2009-02-24 15:30:33 +0000235 * The _oldest/_free ring operations here race cleanly with the alloc/unalloc
236 * operations performed in the send path. As the sender allocs and potentially
237 * unallocs the next free entry in the ring it doesn't alter which is
238 * the next to be freed, which is what this is concerned with.
239 */
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400240void rds_ib_send_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
Andy Grover6a0979d2009-02-24 15:30:33 +0000241{
Andy Groverff3d7d32010-03-01 14:03:09 -0800242 struct rds_message *rm = NULL;
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400243 struct rds_connection *conn = ic->conn;
Andy Grover6a0979d2009-02-24 15:30:33 +0000244 struct rds_ib_send_work *send;
245 u32 completed;
246 u32 oldest;
247 u32 i = 0;
Zach Brownf0460112010-07-14 13:55:35 -0700248 int nr_sig = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000249
Andy Grover6a0979d2009-02-24 15:30:33 +0000250
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400251 rdsdebug("wc wr_id 0x%llx status %u (%s) byte_len %u imm_data %u\n",
252 (unsigned long long)wc->wr_id, wc->status,
253 ib_wc_status_msg(wc->status), wc->byte_len,
254 be32_to_cpu(wc->ex.imm_data));
255 rds_ib_stats_inc(s_ib_tx_cq_event);
Andy Grover6a0979d2009-02-24 15:30:33 +0000256
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400257 if (wc->wr_id == RDS_IB_ACK_WR_ID) {
258 if (time_after(jiffies, ic->i_ack_queued + HZ / 2))
259 rds_ib_stats_inc(s_ib_tx_stalled);
260 rds_ib_ack_send_complete(ic);
261 return;
262 }
Andy Grover6a0979d2009-02-24 15:30:33 +0000263
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400264 oldest = rds_ib_ring_oldest(&ic->i_send_ring);
Andy Grover6a0979d2009-02-24 15:30:33 +0000265
santosh.shilimkar@oracle.comdcfd0412016-03-01 15:20:45 -0800266 completed = rds_ib_ring_completed(&ic->i_send_ring, wc->wr_id, oldest);
Andy Grover6a0979d2009-02-24 15:30:33 +0000267
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400268 for (i = 0; i < completed; i++) {
269 send = &ic->i_sends[oldest];
270 if (send->s_wr.send_flags & IB_SEND_SIGNALED)
271 nr_sig++;
Andy Grover6a0979d2009-02-24 15:30:33 +0000272
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400273 rm = rds_ib_send_unmap_op(ic, send, wc->status);
Andy Grover6a0979d2009-02-24 15:30:33 +0000274
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400275 if (time_after(jiffies, send->s_queued + HZ / 2))
276 rds_ib_stats_inc(s_ib_tx_stalled);
Andy Grover6a0979d2009-02-24 15:30:33 +0000277
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400278 if (send->s_op) {
279 if (send->s_op == rm->m_final_op) {
280 /* If anyone waited for this message to get
281 * flushed out, wake them up now
282 */
283 rds_message_unmapped(rm);
Andy Grover6a0979d2009-02-24 15:30:33 +0000284 }
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400285 rds_message_put(rm);
286 send->s_op = NULL;
Andy Grover6a0979d2009-02-24 15:30:33 +0000287 }
288
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400289 oldest = (oldest + 1) % ic->i_send_ring.w_nr;
290 }
Andy Grover6a0979d2009-02-24 15:30:33 +0000291
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400292 rds_ib_ring_free(&ic->i_send_ring, completed);
293 rds_ib_sub_signaled(ic, nr_sig);
294 nr_sig = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000295
Santosh Shilimkar0c28c042015-09-06 02:18:51 -0400296 if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
297 test_bit(0, &conn->c_map_queued))
298 queue_delayed_work(rds_wq, &conn->c_send_w, 0);
299
300 /* We expect errors as the qp is drained during shutdown */
301 if (wc->status != IB_WC_SUCCESS && rds_conn_up(conn)) {
302 rds_ib_conn_error(conn, "send completion on %pI4 had status %u (%s), disconnecting and reconnecting\n",
303 &conn->c_faddr, wc->status,
304 ib_wc_status_msg(wc->status));
Andy Grover6a0979d2009-02-24 15:30:33 +0000305 }
306}
307
308/*
309 * This is the main function for allocating credits when sending
310 * messages.
311 *
312 * Conceptually, we have two counters:
313 * - send credits: this tells us how many WRs we're allowed
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300314 * to submit without overruning the receiver's queue. For
Andy Grover6a0979d2009-02-24 15:30:33 +0000315 * each SEND WR we post, we decrement this by one.
316 *
317 * - posted credits: this tells us how many WRs we recently
318 * posted to the receive queue. This value is transferred
319 * to the peer as a "credit update" in a RDS header field.
320 * Every time we transmit credits to the peer, we subtract
321 * the amount of transferred credits from this counter.
322 *
323 * It is essential that we avoid situations where both sides have
324 * exhausted their send credits, and are unable to send new credits
325 * to the peer. We achieve this by requiring that we send at least
326 * one credit update to the peer before exhausting our credits.
327 * When new credits arrive, we subtract one credit that is withheld
328 * until we've posted new buffers and are ready to transmit these
329 * credits (see rds_ib_send_add_credits below).
330 *
331 * The RDS send code is essentially single-threaded; rds_send_xmit
Zach Brown0f4b1c72010-06-04 14:41:41 -0700332 * sets RDS_IN_XMIT to ensure exclusive access to the send ring.
Andy Grover6a0979d2009-02-24 15:30:33 +0000333 * However, the ACK sending code is independent and can race with
334 * message SENDs.
335 *
336 * In the send path, we need to update the counters for send credits
337 * and the counter of posted buffers atomically - when we use the
338 * last available credit, we cannot allow another thread to race us
339 * and grab the posted credits counter. Hence, we have to use a
340 * spinlock to protect the credit counter, or use atomics.
341 *
342 * Spinlocks shared between the send and the receive path are bad,
343 * because they create unnecessary delays. An early implementation
344 * using a spinlock showed a 5% degradation in throughput at some
345 * loads.
346 *
347 * This implementation avoids spinlocks completely, putting both
348 * counters into a single atomic, and updating that atomic using
349 * atomic_add (in the receive path, when receiving fresh credits),
350 * and using atomic_cmpxchg when updating the two counters.
351 */
352int rds_ib_send_grab_credits(struct rds_ib_connection *ic,
Steve Wise7b70d032009-04-09 14:09:39 +0000353 u32 wanted, u32 *adv_credits, int need_posted, int max_posted)
Andy Grover6a0979d2009-02-24 15:30:33 +0000354{
355 unsigned int avail, posted, got = 0, advertise;
356 long oldval, newval;
357
358 *adv_credits = 0;
359 if (!ic->i_flowctl)
360 return wanted;
361
362try_again:
363 advertise = 0;
364 oldval = newval = atomic_read(&ic->i_credits);
365 posted = IB_GET_POST_CREDITS(oldval);
366 avail = IB_GET_SEND_CREDITS(oldval);
367
Rasmus Villemoes11ac1192015-02-05 23:17:20 +0100368 rdsdebug("wanted=%u credits=%u posted=%u\n",
Andy Grover6a0979d2009-02-24 15:30:33 +0000369 wanted, avail, posted);
370
371 /* The last credit must be used to send a credit update. */
372 if (avail && !posted)
373 avail--;
374
375 if (avail < wanted) {
376 struct rds_connection *conn = ic->i_cm_id->context;
377
378 /* Oops, there aren't that many credits left! */
379 set_bit(RDS_LL_SEND_FULL, &conn->c_flags);
380 got = avail;
381 } else {
382 /* Sometimes you get what you want, lalala. */
383 got = wanted;
384 }
385 newval -= IB_SET_SEND_CREDITS(got);
386
387 /*
388 * If need_posted is non-zero, then the caller wants
389 * the posted regardless of whether any send credits are
390 * available.
391 */
392 if (posted && (got || need_posted)) {
Steve Wise7b70d032009-04-09 14:09:39 +0000393 advertise = min_t(unsigned int, posted, max_posted);
Andy Grover6a0979d2009-02-24 15:30:33 +0000394 newval -= IB_SET_POST_CREDITS(advertise);
395 }
396
397 /* Finally bill everything */
398 if (atomic_cmpxchg(&ic->i_credits, oldval, newval) != oldval)
399 goto try_again;
400
401 *adv_credits = advertise;
402 return got;
403}
404
405void rds_ib_send_add_credits(struct rds_connection *conn, unsigned int credits)
406{
407 struct rds_ib_connection *ic = conn->c_transport_data;
408
409 if (credits == 0)
410 return;
411
Rasmus Villemoes11ac1192015-02-05 23:17:20 +0100412 rdsdebug("credits=%u current=%u%s\n",
Andy Grover6a0979d2009-02-24 15:30:33 +0000413 credits,
414 IB_GET_SEND_CREDITS(atomic_read(&ic->i_credits)),
415 test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ? ", ll_send_full" : "");
416
417 atomic_add(IB_SET_SEND_CREDITS(credits), &ic->i_credits);
418 if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags))
419 queue_delayed_work(rds_wq, &conn->c_send_w, 0);
420
421 WARN_ON(IB_GET_SEND_CREDITS(credits) >= 16384);
422
423 rds_ib_stats_inc(s_ib_rx_credit_updates);
424}
425
426void rds_ib_advertise_credits(struct rds_connection *conn, unsigned int posted)
427{
428 struct rds_ib_connection *ic = conn->c_transport_data;
429
430 if (posted == 0)
431 return;
432
433 atomic_add(IB_SET_POST_CREDITS(posted), &ic->i_credits);
434
435 /* Decide whether to send an update to the peer now.
436 * If we would send a credit update for every single buffer we
437 * post, we would end up with an ACK storm (ACK arrives,
438 * consumes buffer, we refill the ring, send ACK to remote
439 * advertising the newly posted buffer... ad inf)
440 *
441 * Performance pretty much depends on how often we send
442 * credit updates - too frequent updates mean lots of ACKs.
443 * Too infrequent updates, and the peer will run out of
444 * credits and has to throttle.
445 * For the time being, 16 seems to be a good compromise.
446 */
447 if (IB_GET_POST_CREDITS(atomic_read(&ic->i_credits)) >= 16)
448 set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
449}
450
Zach Brownf0460112010-07-14 13:55:35 -0700451static inline int rds_ib_set_wr_signal_state(struct rds_ib_connection *ic,
452 struct rds_ib_send_work *send,
453 bool notify)
Andy Grover241eef32010-01-19 21:25:26 -0800454{
455 /*
456 * We want to delay signaling completions just enough to get
457 * the batching benefits but not so much that we create dead time
458 * on the wire.
459 */
460 if (ic->i_unsignaled_wrs-- == 0 || notify) {
461 ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs;
462 send->s_wr.send_flags |= IB_SEND_SIGNALED;
Zach Brownf0460112010-07-14 13:55:35 -0700463 return 1;
Andy Grover241eef32010-01-19 21:25:26 -0800464 }
Zach Brownf0460112010-07-14 13:55:35 -0700465 return 0;
Andy Grover241eef32010-01-19 21:25:26 -0800466}
467
Andy Grover6a0979d2009-02-24 15:30:33 +0000468/*
469 * This can be called multiple times for a given message. The first time
470 * we see a message we map its scatterlist into the IB device so that
471 * we can provide that mapped address to the IB scatter gather entries
472 * in the IB work requests. We translate the scatterlist into a series
473 * of work requests that fragment the message. These work requests complete
474 * in order so we pass ownership of the message to the completion handler
475 * once we send the final fragment.
476 *
477 * The RDS core uses the c_send_lock to only enter this function once
478 * per connection. This makes sure that the tx ring alloc/unalloc pairs
479 * don't get out of sync and confuse the ring.
480 */
481int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm,
482 unsigned int hdr_off, unsigned int sg, unsigned int off)
483{
484 struct rds_ib_connection *ic = conn->c_transport_data;
485 struct ib_device *dev = ic->i_cm_id->device;
486 struct rds_ib_send_work *send = NULL;
487 struct rds_ib_send_work *first;
488 struct rds_ib_send_work *prev;
489 struct ib_send_wr *failed_wr;
490 struct scatterlist *scat;
491 u32 pos;
492 u32 i;
493 u32 work_alloc;
Andy Groverda5a06c2010-01-14 12:18:11 -0800494 u32 credit_alloc = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000495 u32 posted;
496 u32 adv_credits = 0;
497 int send_flags = 0;
Andy Groverda5a06c2010-01-14 12:18:11 -0800498 int bytes_sent = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000499 int ret;
500 int flow_controlled = 0;
Zach Brownf0460112010-07-14 13:55:35 -0700501 int nr_sig = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000502
503 BUG_ON(off % RDS_FRAG_SIZE);
504 BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header));
505
Andy Grover2e7b3b92010-03-11 13:49:59 +0000506 /* Do not send cong updates to IB loopback */
507 if (conn->c_loopback
508 && rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) {
509 rds_cong_map_updated(conn->c_fcong, ~(u64) 0);
Neil Horman60946282011-03-02 06:28:22 +0000510 scat = &rm->data.op_sg[sg];
Venkat Venkatsubra18fc25c2013-12-02 15:41:39 -0800511 ret = max_t(int, RDS_CONG_MAP_BYTES, scat->length);
512 return sizeof(struct rds_header) + ret;
Andy Grover2e7b3b92010-03-11 13:49:59 +0000513 }
514
Andy Grover6a0979d2009-02-24 15:30:33 +0000515 /* FIXME we may overallocate here */
516 if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0)
517 i = 1;
518 else
519 i = ceil(be32_to_cpu(rm->m_inc.i_hdr.h_len), RDS_FRAG_SIZE);
520
521 work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos);
522 if (work_alloc == 0) {
523 set_bit(RDS_LL_SEND_FULL, &conn->c_flags);
524 rds_ib_stats_inc(s_ib_tx_ring_full);
525 ret = -ENOMEM;
526 goto out;
527 }
528
Andy Grover6a0979d2009-02-24 15:30:33 +0000529 if (ic->i_flowctl) {
Steve Wise7b70d032009-04-09 14:09:39 +0000530 credit_alloc = rds_ib_send_grab_credits(ic, work_alloc, &posted, 0, RDS_MAX_ADV_CREDIT);
Andy Grover6a0979d2009-02-24 15:30:33 +0000531 adv_credits += posted;
532 if (credit_alloc < work_alloc) {
533 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - credit_alloc);
534 work_alloc = credit_alloc;
Andy Groverc8de3f12010-01-15 15:55:26 -0800535 flow_controlled = 1;
Andy Grover6a0979d2009-02-24 15:30:33 +0000536 }
537 if (work_alloc == 0) {
Steve Wised39e0602009-04-09 14:09:38 +0000538 set_bit(RDS_LL_SEND_FULL, &conn->c_flags);
Andy Grover6a0979d2009-02-24 15:30:33 +0000539 rds_ib_stats_inc(s_ib_tx_throttle);
540 ret = -ENOMEM;
541 goto out;
542 }
543 }
544
545 /* map the message the first time we see it */
Andy Groverff3d7d32010-03-01 14:03:09 -0800546 if (!ic->i_data_op) {
Andy Grover6c7cc6e2010-01-27 18:04:18 -0800547 if (rm->data.op_nents) {
548 rm->data.op_count = ib_dma_map_sg(dev,
549 rm->data.op_sg,
550 rm->data.op_nents,
551 DMA_TO_DEVICE);
552 rdsdebug("ic %p mapping rm %p: %d\n", ic, rm, rm->data.op_count);
553 if (rm->data.op_count == 0) {
Andy Grover6a0979d2009-02-24 15:30:33 +0000554 rds_ib_stats_inc(s_ib_tx_sg_mapping_failure);
555 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
556 ret = -ENOMEM; /* XXX ? */
557 goto out;
558 }
559 } else {
Andy Grover6c7cc6e2010-01-27 18:04:18 -0800560 rm->data.op_count = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000561 }
562
Andy Grover6a0979d2009-02-24 15:30:33 +0000563 rds_message_addref(rm);
Wengang Wangd655a9f2015-05-21 13:11:40 +0800564 rm->data.op_dmasg = 0;
565 rm->data.op_dmaoff = 0;
Andy Groverff3d7d32010-03-01 14:03:09 -0800566 ic->i_data_op = &rm->data;
Andy Grover6a0979d2009-02-24 15:30:33 +0000567
568 /* Finalize the header */
569 if (test_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags))
570 rm->m_inc.i_hdr.h_flags |= RDS_FLAG_ACK_REQUIRED;
571 if (test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))
572 rm->m_inc.i_hdr.h_flags |= RDS_FLAG_RETRANSMITTED;
573
574 /* If it has a RDMA op, tell the peer we did it. This is
575 * used by the peer to release use-once RDMA MRs. */
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800576 if (rm->rdma.op_active) {
Andy Grover6a0979d2009-02-24 15:30:33 +0000577 struct rds_ext_header_rdma ext_hdr;
578
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800579 ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.op_rkey);
Andy Grover6a0979d2009-02-24 15:30:33 +0000580 rds_message_add_extension(&rm->m_inc.i_hdr,
581 RDS_EXTHDR_RDMA, &ext_hdr, sizeof(ext_hdr));
582 }
583 if (rm->m_rdma_cookie) {
584 rds_message_add_rdma_dest_extension(&rm->m_inc.i_hdr,
585 rds_rdma_cookie_key(rm->m_rdma_cookie),
586 rds_rdma_cookie_offset(rm->m_rdma_cookie));
587 }
588
589 /* Note - rds_ib_piggyb_ack clears the ACK_REQUIRED bit, so
590 * we should not do this unless we have a chance of at least
591 * sticking the header into the send ring. Which is why we
592 * should call rds_ib_ring_alloc first. */
593 rm->m_inc.i_hdr.h_ack = cpu_to_be64(rds_ib_piggyb_ack(ic));
594 rds_message_make_checksum(&rm->m_inc.i_hdr);
595
596 /*
597 * Update adv_credits since we reset the ACK_REQUIRED bit.
598 */
Andy Groverc8de3f12010-01-15 15:55:26 -0800599 if (ic->i_flowctl) {
600 rds_ib_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits);
601 adv_credits += posted;
602 BUG_ON(adv_credits > 255);
603 }
Andy Grover735f61e2010-03-11 13:49:55 +0000604 }
Andy Grover6a0979d2009-02-24 15:30:33 +0000605
Andy Grover6a0979d2009-02-24 15:30:33 +0000606 /* Sometimes you want to put a fence between an RDMA
607 * READ and the following SEND.
608 * We could either do this all the time
609 * or when requested by the user. Right now, we let
610 * the application choose.
611 */
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800612 if (rm->rdma.op_active && rm->rdma.op_fence)
Andy Grover6a0979d2009-02-24 15:30:33 +0000613 send_flags = IB_SEND_FENCE;
614
Andy Groverda5a06c2010-01-14 12:18:11 -0800615 /* Each frag gets a header. Msgs may be 0 bytes */
616 send = &ic->i_sends[pos];
617 first = send;
618 prev = NULL;
Wengang Wangd655a9f2015-05-21 13:11:40 +0800619 scat = &ic->i_data_op->op_sg[rm->data.op_dmasg];
Andy Groverda5a06c2010-01-14 12:18:11 -0800620 i = 0;
621 do {
622 unsigned int len = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000623
Andy Groverda5a06c2010-01-14 12:18:11 -0800624 /* Set up the header */
625 send->s_wr.send_flags = send_flags;
626 send->s_wr.opcode = IB_WR_SEND;
627 send->s_wr.num_sge = 1;
628 send->s_wr.next = NULL;
629 send->s_queued = jiffies;
630 send->s_op = NULL;
Andy Grover6a0979d2009-02-24 15:30:33 +0000631
Andy Groverda5a06c2010-01-14 12:18:11 -0800632 send->s_sge[0].addr = ic->i_send_hdrs_dma
633 + (pos * sizeof(struct rds_header));
634 send->s_sge[0].length = sizeof(struct rds_header);
Andy Grover6a0979d2009-02-24 15:30:33 +0000635
Andy Groverda5a06c2010-01-14 12:18:11 -0800636 memcpy(&ic->i_send_hdrs[pos], &rm->m_inc.i_hdr, sizeof(struct rds_header));
Andy Grover6a0979d2009-02-24 15:30:33 +0000637
Andy Groverda5a06c2010-01-14 12:18:11 -0800638 /* Set up the data, if present */
639 if (i < work_alloc
Andy Grover6c7cc6e2010-01-27 18:04:18 -0800640 && scat != &rm->data.op_sg[rm->data.op_count]) {
Wengang Wangd655a9f2015-05-21 13:11:40 +0800641 len = min(RDS_FRAG_SIZE,
642 ib_sg_dma_len(dev, scat) - rm->data.op_dmaoff);
Andy Groverda5a06c2010-01-14 12:18:11 -0800643 send->s_wr.num_sge = 2;
644
Wengang Wangd655a9f2015-05-21 13:11:40 +0800645 send->s_sge[1].addr = ib_sg_dma_address(dev, scat);
646 send->s_sge[1].addr += rm->data.op_dmaoff;
Andy Groverda5a06c2010-01-14 12:18:11 -0800647 send->s_sge[1].length = len;
648
649 bytes_sent += len;
Wengang Wangd655a9f2015-05-21 13:11:40 +0800650 rm->data.op_dmaoff += len;
651 if (rm->data.op_dmaoff == ib_sg_dma_len(dev, scat)) {
Andy Groverda5a06c2010-01-14 12:18:11 -0800652 scat++;
Wengang Wangd655a9f2015-05-21 13:11:40 +0800653 rm->data.op_dmasg++;
654 rm->data.op_dmaoff = 0;
Andy Groverda5a06c2010-01-14 12:18:11 -0800655 }
656 }
Andy Grover6a0979d2009-02-24 15:30:33 +0000657
Andy Grover241eef32010-01-19 21:25:26 -0800658 rds_ib_set_wr_signal_state(ic, send, 0);
Andy Grover6a0979d2009-02-24 15:30:33 +0000659
Andy Grover6a0979d2009-02-24 15:30:33 +0000660 /*
661 * Always signal the last one if we're stopping due to flow control.
662 */
Andy Groverc8de3f12010-01-15 15:55:26 -0800663 if (ic->i_flowctl && flow_controlled && i == (work_alloc-1))
Andy Grover6a0979d2009-02-24 15:30:33 +0000664 send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED;
665
Zach Brownf0460112010-07-14 13:55:35 -0700666 if (send->s_wr.send_flags & IB_SEND_SIGNALED)
667 nr_sig++;
668
Andy Grover6a0979d2009-02-24 15:30:33 +0000669 rdsdebug("send %p wr %p num_sge %u next %p\n", send,
670 &send->s_wr, send->s_wr.num_sge, send->s_wr.next);
671
Andy Groverc8de3f12010-01-15 15:55:26 -0800672 if (ic->i_flowctl && adv_credits) {
Andy Grover6a0979d2009-02-24 15:30:33 +0000673 struct rds_header *hdr = &ic->i_send_hdrs[pos];
674
675 /* add credit and redo the header checksum */
676 hdr->h_credit = adv_credits;
677 rds_message_make_checksum(hdr);
678 adv_credits = 0;
679 rds_ib_stats_inc(s_ib_tx_credit_updates);
680 }
681
682 if (prev)
683 prev->s_wr.next = &send->s_wr;
684 prev = send;
685
686 pos = (pos + 1) % ic->i_send_ring.w_nr;
Andy Groverda5a06c2010-01-14 12:18:11 -0800687 send = &ic->i_sends[pos];
688 i++;
689
690 } while (i < work_alloc
Andy Grover6c7cc6e2010-01-27 18:04:18 -0800691 && scat != &rm->data.op_sg[rm->data.op_count]);
Andy Grover6a0979d2009-02-24 15:30:33 +0000692
693 /* Account the RDS header in the number of bytes we sent, but just once.
694 * The caller has no concept of fragmentation. */
695 if (hdr_off == 0)
Andy Groverda5a06c2010-01-14 12:18:11 -0800696 bytes_sent += sizeof(struct rds_header);
Andy Grover6a0979d2009-02-24 15:30:33 +0000697
698 /* if we finished the message then send completion owns it */
Andy Grover6c7cc6e2010-01-27 18:04:18 -0800699 if (scat == &rm->data.op_sg[rm->data.op_count]) {
Andy Groverff3d7d32010-03-01 14:03:09 -0800700 prev->s_op = ic->i_data_op;
Andy Grover241eef32010-01-19 21:25:26 -0800701 prev->s_wr.send_flags |= IB_SEND_SOLICITED;
santosh.shilimkar@oracle.com30491472015-08-22 15:45:30 -0700702 if (!(prev->s_wr.send_flags & IB_SEND_SIGNALED)) {
703 ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs;
704 prev->s_wr.send_flags |= IB_SEND_SIGNALED;
705 nr_sig++;
706 }
Andy Groverff3d7d32010-03-01 14:03:09 -0800707 ic->i_data_op = NULL;
Andy Grover6a0979d2009-02-24 15:30:33 +0000708 }
709
Andy Groverda5a06c2010-01-14 12:18:11 -0800710 /* Put back wrs & credits we didn't use */
Andy Grover6a0979d2009-02-24 15:30:33 +0000711 if (i < work_alloc) {
712 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i);
713 work_alloc = i;
714 }
715 if (ic->i_flowctl && i < credit_alloc)
716 rds_ib_send_add_credits(conn, credit_alloc - i);
717
Zach Brownf0460112010-07-14 13:55:35 -0700718 if (nr_sig)
719 atomic_add(nr_sig, &ic->i_signaled_sends);
720
Andy Grover6a0979d2009-02-24 15:30:33 +0000721 /* XXX need to worry about failed_wr and partial sends. */
722 failed_wr = &first->s_wr;
723 ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr);
724 rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic,
725 first, &first->s_wr, ret, failed_wr);
726 BUG_ON(failed_wr != &first->s_wr);
727 if (ret) {
728 printk(KERN_WARNING "RDS/IB: ib_post_send to %pI4 "
729 "returned %d\n", &conn->c_faddr, ret);
730 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
Zach Brownf0460112010-07-14 13:55:35 -0700731 rds_ib_sub_signaled(ic, nr_sig);
Andy Groverff3d7d32010-03-01 14:03:09 -0800732 if (prev->s_op) {
733 ic->i_data_op = prev->s_op;
734 prev->s_op = NULL;
Andy Grover6a0979d2009-02-24 15:30:33 +0000735 }
Andy Grover735f61e2010-03-11 13:49:55 +0000736
737 rds_ib_conn_error(ic->conn, "ib_post_send failed\n");
Andy Grover6a0979d2009-02-24 15:30:33 +0000738 goto out;
739 }
740
Andy Groverda5a06c2010-01-14 12:18:11 -0800741 ret = bytes_sent;
Andy Grover6a0979d2009-02-24 15:30:33 +0000742out:
743 BUG_ON(adv_credits);
744 return ret;
745}
746
Andy Grover15133f62010-01-12 14:33:38 -0800747/*
748 * Issue atomic operation.
749 * A simplified version of the rdma case, we always map 1 SG, and
750 * only 8 bytes, for the return value from the atomic operation.
751 */
Andy Groverff3d7d32010-03-01 14:03:09 -0800752int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op)
Andy Grover15133f62010-01-12 14:33:38 -0800753{
754 struct rds_ib_connection *ic = conn->c_transport_data;
755 struct rds_ib_send_work *send = NULL;
756 struct ib_send_wr *failed_wr;
757 struct rds_ib_device *rds_ibdev;
758 u32 pos;
759 u32 work_alloc;
760 int ret;
Zach Brownf0460112010-07-14 13:55:35 -0700761 int nr_sig = 0;
Andy Grover15133f62010-01-12 14:33:38 -0800762
763 rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client);
764
765 work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, 1, &pos);
766 if (work_alloc != 1) {
767 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
768 rds_ib_stats_inc(s_ib_tx_ring_full);
769 ret = -ENOMEM;
770 goto out;
771 }
772
773 /* address of send request in ring */
774 send = &ic->i_sends[pos];
775 send->s_queued = jiffies;
776
777 if (op->op_type == RDS_ATOMIC_TYPE_CSWP) {
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100778 send->s_atomic_wr.wr.opcode = IB_WR_MASKED_ATOMIC_CMP_AND_SWP;
779 send->s_atomic_wr.compare_add = op->op_m_cswp.compare;
780 send->s_atomic_wr.swap = op->op_m_cswp.swap;
781 send->s_atomic_wr.compare_add_mask = op->op_m_cswp.compare_mask;
782 send->s_atomic_wr.swap_mask = op->op_m_cswp.swap_mask;
Andy Grover15133f62010-01-12 14:33:38 -0800783 } else { /* FADD */
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100784 send->s_atomic_wr.wr.opcode = IB_WR_MASKED_ATOMIC_FETCH_AND_ADD;
785 send->s_atomic_wr.compare_add = op->op_m_fadd.add;
786 send->s_atomic_wr.swap = 0;
787 send->s_atomic_wr.compare_add_mask = op->op_m_fadd.nocarry_mask;
788 send->s_atomic_wr.swap_mask = 0;
Andy Grover15133f62010-01-12 14:33:38 -0800789 }
Zach Brownf0460112010-07-14 13:55:35 -0700790 nr_sig = rds_ib_set_wr_signal_state(ic, send, op->op_notify);
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100791 send->s_atomic_wr.wr.num_sge = 1;
792 send->s_atomic_wr.wr.next = NULL;
793 send->s_atomic_wr.remote_addr = op->op_remote_addr;
794 send->s_atomic_wr.rkey = op->op_rkey;
Chris Mason1cc22282010-05-11 16:15:35 -0700795 send->s_op = op;
796 rds_message_addref(container_of(send->s_op, struct rds_message, atomic));
Andy Grover15133f62010-01-12 14:33:38 -0800797
798 /* map 8 byte retval buffer to the device */
799 ret = ib_dma_map_sg(ic->i_cm_id->device, op->op_sg, 1, DMA_FROM_DEVICE);
800 rdsdebug("ic %p mapping atomic op %p. mapped %d pg\n", ic, op, ret);
801 if (ret != 1) {
802 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
803 rds_ib_stats_inc(s_ib_tx_sg_mapping_failure);
804 ret = -ENOMEM; /* XXX ? */
805 goto out;
806 }
807
808 /* Convert our struct scatterlist to struct ib_sge */
809 send->s_sge[0].addr = ib_sg_dma_address(ic->i_cm_id->device, op->op_sg);
810 send->s_sge[0].length = ib_sg_dma_len(ic->i_cm_id->device, op->op_sg);
Jason Gunthorpee5580242015-07-30 17:22:26 -0600811 send->s_sge[0].lkey = ic->i_pd->local_dma_lkey;
Andy Grover15133f62010-01-12 14:33:38 -0800812
813 rdsdebug("rva %Lx rpa %Lx len %u\n", op->op_remote_addr,
814 send->s_sge[0].addr, send->s_sge[0].length);
815
Zach Brownf0460112010-07-14 13:55:35 -0700816 if (nr_sig)
817 atomic_add(nr_sig, &ic->i_signaled_sends);
818
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100819 failed_wr = &send->s_atomic_wr.wr;
820 ret = ib_post_send(ic->i_cm_id->qp, &send->s_atomic_wr.wr, &failed_wr);
Andy Grover15133f62010-01-12 14:33:38 -0800821 rdsdebug("ic %p send %p (wr %p) ret %d wr %p\n", ic,
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100822 send, &send->s_atomic_wr, ret, failed_wr);
823 BUG_ON(failed_wr != &send->s_atomic_wr.wr);
Andy Grover15133f62010-01-12 14:33:38 -0800824 if (ret) {
825 printk(KERN_WARNING "RDS/IB: atomic ib_post_send to %pI4 "
826 "returned %d\n", &conn->c_faddr, ret);
827 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
Zach Brownf0460112010-07-14 13:55:35 -0700828 rds_ib_sub_signaled(ic, nr_sig);
Andy Grover15133f62010-01-12 14:33:38 -0800829 goto out;
830 }
831
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100832 if (unlikely(failed_wr != &send->s_atomic_wr.wr)) {
Andy Grover15133f62010-01-12 14:33:38 -0800833 printk(KERN_WARNING "RDS/IB: atomic ib_post_send() rc=%d, but failed_wqe updated!\n", ret);
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100834 BUG_ON(failed_wr != &send->s_atomic_wr.wr);
Andy Grover15133f62010-01-12 14:33:38 -0800835 }
836
837out:
838 return ret;
839}
840
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800841int rds_ib_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op)
Andy Grover6a0979d2009-02-24 15:30:33 +0000842{
843 struct rds_ib_connection *ic = conn->c_transport_data;
844 struct rds_ib_send_work *send = NULL;
845 struct rds_ib_send_work *first;
846 struct rds_ib_send_work *prev;
847 struct ib_send_wr *failed_wr;
Andy Grover6a0979d2009-02-24 15:30:33 +0000848 struct scatterlist *scat;
849 unsigned long len;
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800850 u64 remote_addr = op->op_remote_addr;
Zach Brown89bf9d42010-05-18 15:44:50 -0700851 u32 max_sge = ic->rds_ibdev->max_sge;
Andy Grover6a0979d2009-02-24 15:30:33 +0000852 u32 pos;
853 u32 work_alloc;
854 u32 i;
855 u32 j;
856 int sent;
857 int ret;
858 int num_sge;
Zach Brownf0460112010-07-14 13:55:35 -0700859 int nr_sig = 0;
Andy Grover6a0979d2009-02-24 15:30:33 +0000860
Andy Groverff3d7d32010-03-01 14:03:09 -0800861 /* map the op the first time we see it */
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800862 if (!op->op_mapped) {
863 op->op_count = ib_dma_map_sg(ic->i_cm_id->device,
864 op->op_sg, op->op_nents, (op->op_write) ?
865 DMA_TO_DEVICE : DMA_FROM_DEVICE);
866 rdsdebug("ic %p mapping op %p: %d\n", ic, op, op->op_count);
867 if (op->op_count == 0) {
Andy Grover6a0979d2009-02-24 15:30:33 +0000868 rds_ib_stats_inc(s_ib_tx_sg_mapping_failure);
869 ret = -ENOMEM; /* XXX ? */
870 goto out;
871 }
872
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800873 op->op_mapped = 1;
Andy Grover6a0979d2009-02-24 15:30:33 +0000874 }
875
876 /*
877 * Instead of knowing how to return a partial rdma read/write we insist that there
878 * be enough work requests to send the entire message.
879 */
Zach Brown89bf9d42010-05-18 15:44:50 -0700880 i = ceil(op->op_count, max_sge);
Andy Grover6a0979d2009-02-24 15:30:33 +0000881
882 work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos);
883 if (work_alloc != i) {
884 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
885 rds_ib_stats_inc(s_ib_tx_ring_full);
886 ret = -ENOMEM;
887 goto out;
888 }
889
890 send = &ic->i_sends[pos];
891 first = send;
892 prev = NULL;
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800893 scat = &op->op_sg[0];
Andy Grover6a0979d2009-02-24 15:30:33 +0000894 sent = 0;
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800895 num_sge = op->op_count;
Andy Grover6a0979d2009-02-24 15:30:33 +0000896
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800897 for (i = 0; i < work_alloc && scat != &op->op_sg[op->op_count]; i++) {
Andy Grover6a0979d2009-02-24 15:30:33 +0000898 send->s_wr.send_flags = 0;
899 send->s_queued = jiffies;
Chris Mason1cc22282010-05-11 16:15:35 -0700900 send->s_op = NULL;
Andy Grover241eef32010-01-19 21:25:26 -0800901
Zach Brownf0460112010-07-14 13:55:35 -0700902 nr_sig += rds_ib_set_wr_signal_state(ic, send, op->op_notify);
Andy Grover6a0979d2009-02-24 15:30:33 +0000903
Andy Groverf8b3aaf2010-03-01 14:11:53 -0800904 send->s_wr.opcode = op->op_write ? IB_WR_RDMA_WRITE : IB_WR_RDMA_READ;
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100905 send->s_rdma_wr.remote_addr = remote_addr;
906 send->s_rdma_wr.rkey = op->op_rkey;
Andy Grover6a0979d2009-02-24 15:30:33 +0000907
Zach Brown89bf9d42010-05-18 15:44:50 -0700908 if (num_sge > max_sge) {
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100909 send->s_rdma_wr.wr.num_sge = max_sge;
Zach Brown89bf9d42010-05-18 15:44:50 -0700910 num_sge -= max_sge;
Andy Grover6a0979d2009-02-24 15:30:33 +0000911 } else {
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100912 send->s_rdma_wr.wr.num_sge = num_sge;
Andy Grover6a0979d2009-02-24 15:30:33 +0000913 }
914
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100915 send->s_rdma_wr.wr.next = NULL;
Andy Grover6a0979d2009-02-24 15:30:33 +0000916
917 if (prev)
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100918 prev->s_rdma_wr.wr.next = &send->s_rdma_wr.wr;
Andy Grover6a0979d2009-02-24 15:30:33 +0000919
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100920 for (j = 0; j < send->s_rdma_wr.wr.num_sge &&
921 scat != &op->op_sg[op->op_count]; j++) {
Andy Grover6a0979d2009-02-24 15:30:33 +0000922 len = ib_sg_dma_len(ic->i_cm_id->device, scat);
923 send->s_sge[j].addr =
924 ib_sg_dma_address(ic->i_cm_id->device, scat);
925 send->s_sge[j].length = len;
Jason Gunthorpee5580242015-07-30 17:22:26 -0600926 send->s_sge[j].lkey = ic->i_pd->local_dma_lkey;
Andy Grover6a0979d2009-02-24 15:30:33 +0000927
928 sent += len;
929 rdsdebug("ic %p sent %d remote_addr %llu\n", ic, sent, remote_addr);
930
931 remote_addr += len;
932 scat++;
933 }
934
935 rdsdebug("send %p wr %p num_sge %u next %p\n", send,
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100936 &send->s_rdma_wr.wr,
937 send->s_rdma_wr.wr.num_sge,
938 send->s_rdma_wr.wr.next);
Andy Grover6a0979d2009-02-24 15:30:33 +0000939
940 prev = send;
941 if (++send == &ic->i_sends[ic->i_send_ring.w_nr])
942 send = ic->i_sends;
943 }
944
Chris Mason1cc22282010-05-11 16:15:35 -0700945 /* give a reference to the last op */
946 if (scat == &op->op_sg[op->op_count]) {
947 prev->s_op = op;
948 rds_message_addref(container_of(op, struct rds_message, rdma));
949 }
950
Andy Grover6a0979d2009-02-24 15:30:33 +0000951 if (i < work_alloc) {
952 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i);
953 work_alloc = i;
954 }
955
Zach Brownf0460112010-07-14 13:55:35 -0700956 if (nr_sig)
957 atomic_add(nr_sig, &ic->i_signaled_sends);
958
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100959 failed_wr = &first->s_rdma_wr.wr;
960 ret = ib_post_send(ic->i_cm_id->qp, &first->s_rdma_wr.wr, &failed_wr);
Andy Grover6a0979d2009-02-24 15:30:33 +0000961 rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic,
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100962 first, &first->s_rdma_wr.wr, ret, failed_wr);
963 BUG_ON(failed_wr != &first->s_rdma_wr.wr);
Andy Grover6a0979d2009-02-24 15:30:33 +0000964 if (ret) {
965 printk(KERN_WARNING "RDS/IB: rdma ib_post_send to %pI4 "
966 "returned %d\n", &conn->c_faddr, ret);
967 rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc);
Zach Brownf0460112010-07-14 13:55:35 -0700968 rds_ib_sub_signaled(ic, nr_sig);
Andy Grover6a0979d2009-02-24 15:30:33 +0000969 goto out;
970 }
971
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100972 if (unlikely(failed_wr != &first->s_rdma_wr.wr)) {
Andy Grover6a0979d2009-02-24 15:30:33 +0000973 printk(KERN_WARNING "RDS/IB: ib_post_send() rc=%d, but failed_wqe updated!\n", ret);
Christoph Hellwige622f2f2015-10-08 09:16:33 +0100974 BUG_ON(failed_wr != &first->s_rdma_wr.wr);
Andy Grover6a0979d2009-02-24 15:30:33 +0000975 }
976
977
978out:
979 return ret;
980}
981
982void rds_ib_xmit_complete(struct rds_connection *conn)
983{
984 struct rds_ib_connection *ic = conn->c_transport_data;
985
986 /* We may have a pending ACK or window update we were unable
987 * to send previously (due to flow control). Try again. */
988 rds_ib_attempt_ack(ic);
989}