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6a0979df AG |
1 | /* |
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> | |
37 | ||
38 | #include "rds.h" | |
6a0979df AG |
39 | #include "ib.h" |
40 | ||
9c030391 AG |
41 | /* |
42 | * Convert IB-specific error message to RDS error message and call core | |
43 | * completion handler. | |
44 | */ | |
45 | static void rds_ib_send_complete(struct rds_message *rm, | |
46 | int wc_status, | |
47 | void (*complete)(struct rds_message *rm, int status)) | |
6a0979df AG |
48 | { |
49 | int notify_status; | |
50 | ||
51 | switch (wc_status) { | |
52 | case IB_WC_WR_FLUSH_ERR: | |
53 | return; | |
54 | ||
55 | case IB_WC_SUCCESS: | |
56 | notify_status = RDS_RDMA_SUCCESS; | |
57 | break; | |
58 | ||
59 | case IB_WC_REM_ACCESS_ERR: | |
60 | notify_status = RDS_RDMA_REMOTE_ERROR; | |
61 | break; | |
62 | ||
63 | default: | |
64 | notify_status = RDS_RDMA_OTHER_ERROR; | |
65 | break; | |
66 | } | |
9c030391 | 67 | complete(rm, notify_status); |
6a0979df AG |
68 | } |
69 | ||
ff3d7d36 AG |
70 | static void rds_ib_send_unmap_data(struct rds_ib_connection *ic, |
71 | struct rm_data_op *op, | |
72 | int wc_status) | |
6a0979df | 73 | { |
ff3d7d36 AG |
74 | if (op->op_nents) |
75 | ib_dma_unmap_sg(ic->i_cm_id->device, | |
76 | op->op_sg, op->op_nents, | |
77 | DMA_TO_DEVICE); | |
78 | } | |
6a0979df | 79 | |
ff3d7d36 AG |
80 | static void rds_ib_send_unmap_rdma(struct rds_ib_connection *ic, |
81 | struct rm_rdma_op *op, | |
82 | int wc_status) | |
83 | { | |
84 | if (op->op_mapped) { | |
85 | ib_dma_unmap_sg(ic->i_cm_id->device, | |
86 | op->op_sg, op->op_nents, | |
87 | op->op_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
88 | op->op_mapped = 0; | |
89 | } | |
15133f6e | 90 | |
ff3d7d36 AG |
91 | /* If the user asked for a completion notification on this |
92 | * message, we can implement three different semantics: | |
93 | * 1. Notify when we received the ACK on the RDS message | |
94 | * that was queued with the RDMA. This provides reliable | |
95 | * notification of RDMA status at the expense of a one-way | |
96 | * packet delay. | |
97 | * 2. Notify when the IB stack gives us the completion event for | |
98 | * the RDMA operation. | |
99 | * 3. Notify when the IB stack gives us the completion event for | |
100 | * the accompanying RDS messages. | |
101 | * Here, we implement approach #3. To implement approach #2, | |
102 | * we would need to take an event for the rdma WR. To implement #1, | |
103 | * don't call rds_rdma_send_complete at all, and fall back to the notify | |
104 | * handling in the ACK processing code. | |
105 | * | |
106 | * Note: There's no need to explicitly sync any RDMA buffers using | |
107 | * ib_dma_sync_sg_for_cpu - the completion for the RDMA | |
108 | * operation itself unmapped the RDMA buffers, which takes care | |
109 | * of synching. | |
110 | */ | |
111 | rds_ib_send_complete(container_of(op, struct rds_message, rdma), | |
112 | wc_status, rds_rdma_send_complete); | |
6a0979df | 113 | |
ff3d7d36 AG |
114 | if (op->op_write) |
115 | rds_stats_add(s_send_rdma_bytes, op->op_bytes); | |
116 | else | |
117 | rds_stats_add(s_recv_rdma_bytes, op->op_bytes); | |
118 | } | |
6a0979df | 119 | |
ff3d7d36 AG |
120 | static void rds_ib_send_unmap_atomic(struct rds_ib_connection *ic, |
121 | struct rm_atomic_op *op, | |
122 | int wc_status) | |
123 | { | |
124 | /* unmap atomic recvbuf */ | |
125 | if (op->op_mapped) { | |
126 | ib_dma_unmap_sg(ic->i_cm_id->device, op->op_sg, 1, | |
127 | DMA_FROM_DEVICE); | |
128 | op->op_mapped = 0; | |
6a0979df AG |
129 | } |
130 | ||
ff3d7d36 AG |
131 | rds_ib_send_complete(container_of(op, struct rds_message, atomic), |
132 | wc_status, rds_atomic_send_complete); | |
15133f6e | 133 | |
ff3d7d36 | 134 | if (op->op_type == RDS_ATOMIC_TYPE_CSWP) |
51e2cba8 | 135 | rds_ib_stats_inc(s_ib_atomic_cswp); |
ff3d7d36 | 136 | else |
51e2cba8 | 137 | rds_ib_stats_inc(s_ib_atomic_fadd); |
ff3d7d36 | 138 | } |
15133f6e | 139 | |
ff3d7d36 AG |
140 | /* |
141 | * Unmap the resources associated with a struct send_work. | |
142 | * | |
143 | * Returns the rm for no good reason other than it is unobtainable | |
144 | * other than by switching on wr.opcode, currently, and the caller, | |
145 | * the event handler, needs it. | |
146 | */ | |
147 | static struct rds_message *rds_ib_send_unmap_op(struct rds_ib_connection *ic, | |
148 | struct rds_ib_send_work *send, | |
149 | int wc_status) | |
150 | { | |
151 | struct rds_message *rm = NULL; | |
152 | ||
153 | /* In the error case, wc.opcode sometimes contains garbage */ | |
154 | switch (send->s_wr.opcode) { | |
155 | case IB_WR_SEND: | |
156 | if (send->s_op) { | |
157 | rm = container_of(send->s_op, struct rds_message, data); | |
158 | rds_ib_send_unmap_data(ic, send->s_op, wc_status); | |
159 | } | |
160 | break; | |
161 | case IB_WR_RDMA_WRITE: | |
162 | case IB_WR_RDMA_READ: | |
163 | if (send->s_op) { | |
164 | rm = container_of(send->s_op, struct rds_message, rdma); | |
165 | rds_ib_send_unmap_rdma(ic, send->s_op, wc_status); | |
166 | } | |
167 | break; | |
168 | case IB_WR_ATOMIC_FETCH_AND_ADD: | |
169 | case IB_WR_ATOMIC_CMP_AND_SWP: | |
170 | if (send->s_op) { | |
171 | rm = container_of(send->s_op, struct rds_message, atomic); | |
172 | rds_ib_send_unmap_atomic(ic, send->s_op, wc_status); | |
173 | } | |
174 | break; | |
175 | default: | |
176 | if (printk_ratelimit()) | |
177 | printk(KERN_NOTICE | |
178 | "RDS/IB: %s: unexpected opcode 0x%x in WR!\n", | |
179 | __func__, send->s_wr.opcode); | |
180 | break; | |
15133f6e AG |
181 | } |
182 | ||
ff3d7d36 | 183 | send->s_wr.opcode = 0xdead; |
6a0979df | 184 | |
ff3d7d36 | 185 | return rm; |
6a0979df AG |
186 | } |
187 | ||
188 | void 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 | ||
6a0979df AG |
196 | send->s_op = NULL; |
197 | ||
198 | send->s_wr.wr_id = i; | |
199 | send->s_wr.sg_list = send->s_sge; | |
6a0979df AG |
200 | send->s_wr.ex.imm_data = 0; |
201 | ||
919ced4c | 202 | sge = &send->s_sge[0]; |
6a0979df AG |
203 | sge->addr = ic->i_send_hdrs_dma + (i * sizeof(struct rds_header)); |
204 | sge->length = sizeof(struct rds_header); | |
205 | sge->lkey = ic->i_mr->lkey; | |
919ced4c AG |
206 | |
207 | send->s_sge[1].lkey = ic->i_mr->lkey; | |
6a0979df AG |
208 | } |
209 | } | |
210 | ||
211 | void 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++) { | |
ff3d7d36 AG |
217 | if (send->s_op && send->s_wr.opcode != 0xdead) |
218 | rds_ib_send_unmap_op(ic, send, IB_WC_WR_FLUSH_ERR); | |
6a0979df AG |
219 | } |
220 | } | |
221 | ||
222 | /* | |
223 | * The _oldest/_free ring operations here race cleanly with the alloc/unalloc | |
224 | * operations performed in the send path. As the sender allocs and potentially | |
225 | * unallocs the next free entry in the ring it doesn't alter which is | |
226 | * the next to be freed, which is what this is concerned with. | |
227 | */ | |
228 | void rds_ib_send_cq_comp_handler(struct ib_cq *cq, void *context) | |
229 | { | |
230 | struct rds_connection *conn = context; | |
231 | struct rds_ib_connection *ic = conn->c_transport_data; | |
ff3d7d36 | 232 | struct rds_message *rm = NULL; |
6a0979df AG |
233 | struct ib_wc wc; |
234 | struct rds_ib_send_work *send; | |
235 | u32 completed; | |
236 | u32 oldest; | |
237 | u32 i = 0; | |
238 | int ret; | |
239 | ||
240 | rdsdebug("cq %p conn %p\n", cq, conn); | |
241 | rds_ib_stats_inc(s_ib_tx_cq_call); | |
242 | ret = ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); | |
243 | if (ret) | |
244 | rdsdebug("ib_req_notify_cq send failed: %d\n", ret); | |
245 | ||
246 | while (ib_poll_cq(cq, 1, &wc) > 0) { | |
247 | rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n", | |
248 | (unsigned long long)wc.wr_id, wc.status, wc.byte_len, | |
249 | be32_to_cpu(wc.ex.imm_data)); | |
250 | rds_ib_stats_inc(s_ib_tx_cq_event); | |
251 | ||
252 | if (wc.wr_id == RDS_IB_ACK_WR_ID) { | |
253 | if (ic->i_ack_queued + HZ/2 < jiffies) | |
254 | rds_ib_stats_inc(s_ib_tx_stalled); | |
255 | rds_ib_ack_send_complete(ic); | |
256 | continue; | |
257 | } | |
258 | ||
259 | oldest = rds_ib_ring_oldest(&ic->i_send_ring); | |
260 | ||
261 | completed = rds_ib_ring_completed(&ic->i_send_ring, wc.wr_id, oldest); | |
262 | ||
263 | for (i = 0; i < completed; i++) { | |
264 | send = &ic->i_sends[oldest]; | |
265 | ||
ff3d7d36 | 266 | rm = rds_ib_send_unmap_op(ic, send, wc.status); |
6a0979df | 267 | |
6a0979df AG |
268 | if (send->s_queued + HZ/2 < jiffies) |
269 | rds_ib_stats_inc(s_ib_tx_stalled); | |
270 | ||
c9e65383 CM |
271 | if (send->s_op) { |
272 | if (send->s_op == rm->m_final_op) { | |
273 | /* If anyone waited for this message to get flushed out, wake | |
274 | * them up now */ | |
275 | rds_message_unmapped(rm); | |
276 | } | |
ff3d7d36 AG |
277 | rds_message_put(rm); |
278 | send->s_op = NULL; | |
6a0979df AG |
279 | } |
280 | ||
281 | oldest = (oldest + 1) % ic->i_send_ring.w_nr; | |
282 | } | |
283 | ||
284 | rds_ib_ring_free(&ic->i_send_ring, completed); | |
285 | ||
f64f9e71 JP |
286 | if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags) || |
287 | test_bit(0, &conn->c_map_queued)) | |
6a0979df AG |
288 | queue_delayed_work(rds_wq, &conn->c_send_w, 0); |
289 | ||
290 | /* We expect errors as the qp is drained during shutdown */ | |
291 | if (wc.status != IB_WC_SUCCESS && rds_conn_up(conn)) { | |
292 | rds_ib_conn_error(conn, | |
293 | "send completion on %pI4 " | |
294 | "had status %u, disconnecting and reconnecting\n", | |
295 | &conn->c_faddr, wc.status); | |
296 | } | |
297 | } | |
298 | } | |
299 | ||
300 | /* | |
301 | * This is the main function for allocating credits when sending | |
302 | * messages. | |
303 | * | |
304 | * Conceptually, we have two counters: | |
305 | * - send credits: this tells us how many WRs we're allowed | |
306 | * to submit without overruning the reciever's queue. For | |
307 | * each SEND WR we post, we decrement this by one. | |
308 | * | |
309 | * - posted credits: this tells us how many WRs we recently | |
310 | * posted to the receive queue. This value is transferred | |
311 | * to the peer as a "credit update" in a RDS header field. | |
312 | * Every time we transmit credits to the peer, we subtract | |
313 | * the amount of transferred credits from this counter. | |
314 | * | |
315 | * It is essential that we avoid situations where both sides have | |
316 | * exhausted their send credits, and are unable to send new credits | |
317 | * to the peer. We achieve this by requiring that we send at least | |
318 | * one credit update to the peer before exhausting our credits. | |
319 | * When new credits arrive, we subtract one credit that is withheld | |
320 | * until we've posted new buffers and are ready to transmit these | |
321 | * credits (see rds_ib_send_add_credits below). | |
322 | * | |
323 | * The RDS send code is essentially single-threaded; rds_send_xmit | |
324 | * grabs c_send_lock to ensure exclusive access to the send ring. | |
325 | * However, the ACK sending code is independent and can race with | |
326 | * message SENDs. | |
327 | * | |
328 | * In the send path, we need to update the counters for send credits | |
329 | * and the counter of posted buffers atomically - when we use the | |
330 | * last available credit, we cannot allow another thread to race us | |
331 | * and grab the posted credits counter. Hence, we have to use a | |
332 | * spinlock to protect the credit counter, or use atomics. | |
333 | * | |
334 | * Spinlocks shared between the send and the receive path are bad, | |
335 | * because they create unnecessary delays. An early implementation | |
336 | * using a spinlock showed a 5% degradation in throughput at some | |
337 | * loads. | |
338 | * | |
339 | * This implementation avoids spinlocks completely, putting both | |
340 | * counters into a single atomic, and updating that atomic using | |
341 | * atomic_add (in the receive path, when receiving fresh credits), | |
342 | * and using atomic_cmpxchg when updating the two counters. | |
343 | */ | |
344 | int rds_ib_send_grab_credits(struct rds_ib_connection *ic, | |
7b70d033 | 345 | u32 wanted, u32 *adv_credits, int need_posted, int max_posted) |
6a0979df AG |
346 | { |
347 | unsigned int avail, posted, got = 0, advertise; | |
348 | long oldval, newval; | |
349 | ||
350 | *adv_credits = 0; | |
351 | if (!ic->i_flowctl) | |
352 | return wanted; | |
353 | ||
354 | try_again: | |
355 | advertise = 0; | |
356 | oldval = newval = atomic_read(&ic->i_credits); | |
357 | posted = IB_GET_POST_CREDITS(oldval); | |
358 | avail = IB_GET_SEND_CREDITS(oldval); | |
359 | ||
360 | rdsdebug("rds_ib_send_grab_credits(%u): credits=%u posted=%u\n", | |
361 | wanted, avail, posted); | |
362 | ||
363 | /* The last credit must be used to send a credit update. */ | |
364 | if (avail && !posted) | |
365 | avail--; | |
366 | ||
367 | if (avail < wanted) { | |
368 | struct rds_connection *conn = ic->i_cm_id->context; | |
369 | ||
370 | /* Oops, there aren't that many credits left! */ | |
371 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); | |
372 | got = avail; | |
373 | } else { | |
374 | /* Sometimes you get what you want, lalala. */ | |
375 | got = wanted; | |
376 | } | |
377 | newval -= IB_SET_SEND_CREDITS(got); | |
378 | ||
379 | /* | |
380 | * If need_posted is non-zero, then the caller wants | |
381 | * the posted regardless of whether any send credits are | |
382 | * available. | |
383 | */ | |
384 | if (posted && (got || need_posted)) { | |
7b70d033 | 385 | advertise = min_t(unsigned int, posted, max_posted); |
6a0979df AG |
386 | newval -= IB_SET_POST_CREDITS(advertise); |
387 | } | |
388 | ||
389 | /* Finally bill everything */ | |
390 | if (atomic_cmpxchg(&ic->i_credits, oldval, newval) != oldval) | |
391 | goto try_again; | |
392 | ||
393 | *adv_credits = advertise; | |
394 | return got; | |
395 | } | |
396 | ||
397 | void rds_ib_send_add_credits(struct rds_connection *conn, unsigned int credits) | |
398 | { | |
399 | struct rds_ib_connection *ic = conn->c_transport_data; | |
400 | ||
401 | if (credits == 0) | |
402 | return; | |
403 | ||
404 | rdsdebug("rds_ib_send_add_credits(%u): current=%u%s\n", | |
405 | credits, | |
406 | IB_GET_SEND_CREDITS(atomic_read(&ic->i_credits)), | |
407 | test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ? ", ll_send_full" : ""); | |
408 | ||
409 | atomic_add(IB_SET_SEND_CREDITS(credits), &ic->i_credits); | |
410 | if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags)) | |
411 | queue_delayed_work(rds_wq, &conn->c_send_w, 0); | |
412 | ||
413 | WARN_ON(IB_GET_SEND_CREDITS(credits) >= 16384); | |
414 | ||
415 | rds_ib_stats_inc(s_ib_rx_credit_updates); | |
416 | } | |
417 | ||
418 | void rds_ib_advertise_credits(struct rds_connection *conn, unsigned int posted) | |
419 | { | |
420 | struct rds_ib_connection *ic = conn->c_transport_data; | |
421 | ||
422 | if (posted == 0) | |
423 | return; | |
424 | ||
425 | atomic_add(IB_SET_POST_CREDITS(posted), &ic->i_credits); | |
426 | ||
427 | /* Decide whether to send an update to the peer now. | |
428 | * If we would send a credit update for every single buffer we | |
429 | * post, we would end up with an ACK storm (ACK arrives, | |
430 | * consumes buffer, we refill the ring, send ACK to remote | |
431 | * advertising the newly posted buffer... ad inf) | |
432 | * | |
433 | * Performance pretty much depends on how often we send | |
434 | * credit updates - too frequent updates mean lots of ACKs. | |
435 | * Too infrequent updates, and the peer will run out of | |
436 | * credits and has to throttle. | |
437 | * For the time being, 16 seems to be a good compromise. | |
438 | */ | |
439 | if (IB_GET_POST_CREDITS(atomic_read(&ic->i_credits)) >= 16) | |
440 | set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags); | |
441 | } | |
442 | ||
241eef3e AG |
443 | static inline void rds_ib_set_wr_signal_state(struct rds_ib_connection *ic, |
444 | struct rds_ib_send_work *send, | |
445 | bool notify) | |
446 | { | |
447 | /* | |
448 | * We want to delay signaling completions just enough to get | |
449 | * the batching benefits but not so much that we create dead time | |
450 | * on the wire. | |
451 | */ | |
452 | if (ic->i_unsignaled_wrs-- == 0 || notify) { | |
453 | ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs; | |
454 | send->s_wr.send_flags |= IB_SEND_SIGNALED; | |
455 | } | |
456 | } | |
457 | ||
6a0979df AG |
458 | /* |
459 | * This can be called multiple times for a given message. The first time | |
460 | * we see a message we map its scatterlist into the IB device so that | |
461 | * we can provide that mapped address to the IB scatter gather entries | |
462 | * in the IB work requests. We translate the scatterlist into a series | |
463 | * of work requests that fragment the message. These work requests complete | |
464 | * in order so we pass ownership of the message to the completion handler | |
465 | * once we send the final fragment. | |
466 | * | |
467 | * The RDS core uses the c_send_lock to only enter this function once | |
468 | * per connection. This makes sure that the tx ring alloc/unalloc pairs | |
469 | * don't get out of sync and confuse the ring. | |
470 | */ | |
471 | int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm, | |
472 | unsigned int hdr_off, unsigned int sg, unsigned int off) | |
473 | { | |
474 | struct rds_ib_connection *ic = conn->c_transport_data; | |
475 | struct ib_device *dev = ic->i_cm_id->device; | |
476 | struct rds_ib_send_work *send = NULL; | |
477 | struct rds_ib_send_work *first; | |
478 | struct rds_ib_send_work *prev; | |
479 | struct ib_send_wr *failed_wr; | |
480 | struct scatterlist *scat; | |
481 | u32 pos; | |
482 | u32 i; | |
483 | u32 work_alloc; | |
da5a06ce | 484 | u32 credit_alloc = 0; |
6a0979df AG |
485 | u32 posted; |
486 | u32 adv_credits = 0; | |
487 | int send_flags = 0; | |
da5a06ce | 488 | int bytes_sent = 0; |
6a0979df AG |
489 | int ret; |
490 | int flow_controlled = 0; | |
491 | ||
492 | BUG_ON(off % RDS_FRAG_SIZE); | |
493 | BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header)); | |
494 | ||
2e7b3b99 AG |
495 | /* Do not send cong updates to IB loopback */ |
496 | if (conn->c_loopback | |
497 | && rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) { | |
498 | rds_cong_map_updated(conn->c_fcong, ~(u64) 0); | |
499 | return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES; | |
500 | } | |
501 | ||
6a0979df AG |
502 | /* FIXME we may overallocate here */ |
503 | if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0) | |
504 | i = 1; | |
505 | else | |
506 | i = ceil(be32_to_cpu(rm->m_inc.i_hdr.h_len), RDS_FRAG_SIZE); | |
507 | ||
508 | work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos); | |
509 | if (work_alloc == 0) { | |
510 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); | |
511 | rds_ib_stats_inc(s_ib_tx_ring_full); | |
512 | ret = -ENOMEM; | |
513 | goto out; | |
514 | } | |
515 | ||
6a0979df | 516 | if (ic->i_flowctl) { |
7b70d033 | 517 | credit_alloc = rds_ib_send_grab_credits(ic, work_alloc, &posted, 0, RDS_MAX_ADV_CREDIT); |
6a0979df AG |
518 | adv_credits += posted; |
519 | if (credit_alloc < work_alloc) { | |
520 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - credit_alloc); | |
521 | work_alloc = credit_alloc; | |
c8de3f10 | 522 | flow_controlled = 1; |
6a0979df AG |
523 | } |
524 | if (work_alloc == 0) { | |
d39e0602 | 525 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); |
6a0979df AG |
526 | rds_ib_stats_inc(s_ib_tx_throttle); |
527 | ret = -ENOMEM; | |
528 | goto out; | |
529 | } | |
530 | } | |
531 | ||
532 | /* map the message the first time we see it */ | |
ff3d7d36 | 533 | if (!ic->i_data_op) { |
6c7cc6e4 AG |
534 | if (rm->data.op_nents) { |
535 | rm->data.op_count = ib_dma_map_sg(dev, | |
536 | rm->data.op_sg, | |
537 | rm->data.op_nents, | |
538 | DMA_TO_DEVICE); | |
539 | rdsdebug("ic %p mapping rm %p: %d\n", ic, rm, rm->data.op_count); | |
540 | if (rm->data.op_count == 0) { | |
6a0979df AG |
541 | rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); |
542 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
543 | ret = -ENOMEM; /* XXX ? */ | |
544 | goto out; | |
545 | } | |
546 | } else { | |
6c7cc6e4 | 547 | rm->data.op_count = 0; |
6a0979df AG |
548 | } |
549 | ||
6a0979df | 550 | rds_message_addref(rm); |
ff3d7d36 | 551 | ic->i_data_op = &rm->data; |
6a0979df AG |
552 | |
553 | /* Finalize the header */ | |
554 | if (test_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags)) | |
555 | rm->m_inc.i_hdr.h_flags |= RDS_FLAG_ACK_REQUIRED; | |
556 | if (test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) | |
557 | rm->m_inc.i_hdr.h_flags |= RDS_FLAG_RETRANSMITTED; | |
558 | ||
559 | /* If it has a RDMA op, tell the peer we did it. This is | |
560 | * used by the peer to release use-once RDMA MRs. */ | |
f8b3aaf2 | 561 | if (rm->rdma.op_active) { |
6a0979df AG |
562 | struct rds_ext_header_rdma ext_hdr; |
563 | ||
f8b3aaf2 | 564 | ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.op_rkey); |
6a0979df AG |
565 | rds_message_add_extension(&rm->m_inc.i_hdr, |
566 | RDS_EXTHDR_RDMA, &ext_hdr, sizeof(ext_hdr)); | |
567 | } | |
568 | if (rm->m_rdma_cookie) { | |
569 | rds_message_add_rdma_dest_extension(&rm->m_inc.i_hdr, | |
570 | rds_rdma_cookie_key(rm->m_rdma_cookie), | |
571 | rds_rdma_cookie_offset(rm->m_rdma_cookie)); | |
572 | } | |
573 | ||
574 | /* Note - rds_ib_piggyb_ack clears the ACK_REQUIRED bit, so | |
575 | * we should not do this unless we have a chance of at least | |
576 | * sticking the header into the send ring. Which is why we | |
577 | * should call rds_ib_ring_alloc first. */ | |
578 | rm->m_inc.i_hdr.h_ack = cpu_to_be64(rds_ib_piggyb_ack(ic)); | |
579 | rds_message_make_checksum(&rm->m_inc.i_hdr); | |
580 | ||
581 | /* | |
582 | * Update adv_credits since we reset the ACK_REQUIRED bit. | |
583 | */ | |
c8de3f10 AG |
584 | if (ic->i_flowctl) { |
585 | rds_ib_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits); | |
586 | adv_credits += posted; | |
587 | BUG_ON(adv_credits > 255); | |
588 | } | |
735f61e6 | 589 | } |
6a0979df | 590 | |
6a0979df AG |
591 | /* Sometimes you want to put a fence between an RDMA |
592 | * READ and the following SEND. | |
593 | * We could either do this all the time | |
594 | * or when requested by the user. Right now, we let | |
595 | * the application choose. | |
596 | */ | |
f8b3aaf2 | 597 | if (rm->rdma.op_active && rm->rdma.op_fence) |
6a0979df AG |
598 | send_flags = IB_SEND_FENCE; |
599 | ||
da5a06ce AG |
600 | /* Each frag gets a header. Msgs may be 0 bytes */ |
601 | send = &ic->i_sends[pos]; | |
602 | first = send; | |
603 | prev = NULL; | |
ff3d7d36 | 604 | scat = &ic->i_data_op->op_sg[sg]; |
da5a06ce AG |
605 | i = 0; |
606 | do { | |
607 | unsigned int len = 0; | |
608 | ||
609 | /* Set up the header */ | |
610 | send->s_wr.send_flags = send_flags; | |
611 | send->s_wr.opcode = IB_WR_SEND; | |
612 | send->s_wr.num_sge = 1; | |
613 | send->s_wr.next = NULL; | |
614 | send->s_queued = jiffies; | |
615 | send->s_op = NULL; | |
6a0979df | 616 | |
da5a06ce AG |
617 | send->s_sge[0].addr = ic->i_send_hdrs_dma |
618 | + (pos * sizeof(struct rds_header)); | |
619 | send->s_sge[0].length = sizeof(struct rds_header); | |
620 | ||
621 | memcpy(&ic->i_send_hdrs[pos], &rm->m_inc.i_hdr, sizeof(struct rds_header)); | |
6a0979df | 622 | |
da5a06ce AG |
623 | /* Set up the data, if present */ |
624 | if (i < work_alloc | |
6c7cc6e4 | 625 | && scat != &rm->data.op_sg[rm->data.op_count]) { |
da5a06ce AG |
626 | len = min(RDS_FRAG_SIZE, ib_sg_dma_len(dev, scat) - off); |
627 | send->s_wr.num_sge = 2; | |
6a0979df | 628 | |
da5a06ce AG |
629 | send->s_sge[1].addr = ib_sg_dma_address(dev, scat) + off; |
630 | send->s_sge[1].length = len; | |
6a0979df | 631 | |
da5a06ce AG |
632 | bytes_sent += len; |
633 | off += len; | |
634 | if (off == ib_sg_dma_len(dev, scat)) { | |
635 | scat++; | |
636 | off = 0; | |
637 | } | |
638 | } | |
6a0979df | 639 | |
241eef3e | 640 | rds_ib_set_wr_signal_state(ic, send, 0); |
6a0979df | 641 | |
6a0979df AG |
642 | /* |
643 | * Always signal the last one if we're stopping due to flow control. | |
644 | */ | |
c8de3f10 | 645 | if (ic->i_flowctl && flow_controlled && i == (work_alloc-1)) |
6a0979df AG |
646 | send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; |
647 | ||
648 | rdsdebug("send %p wr %p num_sge %u next %p\n", send, | |
649 | &send->s_wr, send->s_wr.num_sge, send->s_wr.next); | |
650 | ||
c8de3f10 | 651 | if (ic->i_flowctl && adv_credits) { |
6a0979df AG |
652 | struct rds_header *hdr = &ic->i_send_hdrs[pos]; |
653 | ||
654 | /* add credit and redo the header checksum */ | |
655 | hdr->h_credit = adv_credits; | |
656 | rds_message_make_checksum(hdr); | |
657 | adv_credits = 0; | |
658 | rds_ib_stats_inc(s_ib_tx_credit_updates); | |
659 | } | |
660 | ||
661 | if (prev) | |
662 | prev->s_wr.next = &send->s_wr; | |
663 | prev = send; | |
664 | ||
665 | pos = (pos + 1) % ic->i_send_ring.w_nr; | |
da5a06ce AG |
666 | send = &ic->i_sends[pos]; |
667 | i++; | |
668 | ||
669 | } while (i < work_alloc | |
6c7cc6e4 | 670 | && scat != &rm->data.op_sg[rm->data.op_count]); |
6a0979df AG |
671 | |
672 | /* Account the RDS header in the number of bytes we sent, but just once. | |
673 | * The caller has no concept of fragmentation. */ | |
674 | if (hdr_off == 0) | |
da5a06ce | 675 | bytes_sent += sizeof(struct rds_header); |
6a0979df AG |
676 | |
677 | /* if we finished the message then send completion owns it */ | |
6c7cc6e4 | 678 | if (scat == &rm->data.op_sg[rm->data.op_count]) { |
ff3d7d36 | 679 | prev->s_op = ic->i_data_op; |
241eef3e | 680 | prev->s_wr.send_flags |= IB_SEND_SOLICITED; |
ff3d7d36 | 681 | ic->i_data_op = NULL; |
6a0979df AG |
682 | } |
683 | ||
da5a06ce | 684 | /* Put back wrs & credits we didn't use */ |
6a0979df AG |
685 | if (i < work_alloc) { |
686 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i); | |
687 | work_alloc = i; | |
688 | } | |
689 | if (ic->i_flowctl && i < credit_alloc) | |
690 | rds_ib_send_add_credits(conn, credit_alloc - i); | |
691 | ||
692 | /* XXX need to worry about failed_wr and partial sends. */ | |
693 | failed_wr = &first->s_wr; | |
694 | ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr); | |
695 | rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, | |
696 | first, &first->s_wr, ret, failed_wr); | |
697 | BUG_ON(failed_wr != &first->s_wr); | |
698 | if (ret) { | |
699 | printk(KERN_WARNING "RDS/IB: ib_post_send to %pI4 " | |
700 | "returned %d\n", &conn->c_faddr, ret); | |
701 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
ff3d7d36 AG |
702 | if (prev->s_op) { |
703 | ic->i_data_op = prev->s_op; | |
704 | prev->s_op = NULL; | |
6a0979df | 705 | } |
735f61e6 AG |
706 | |
707 | rds_ib_conn_error(ic->conn, "ib_post_send failed\n"); | |
6a0979df AG |
708 | goto out; |
709 | } | |
710 | ||
da5a06ce | 711 | ret = bytes_sent; |
6a0979df AG |
712 | out: |
713 | BUG_ON(adv_credits); | |
714 | return ret; | |
715 | } | |
716 | ||
15133f6e AG |
717 | /* |
718 | * Issue atomic operation. | |
719 | * A simplified version of the rdma case, we always map 1 SG, and | |
720 | * only 8 bytes, for the return value from the atomic operation. | |
721 | */ | |
ff3d7d36 | 722 | int rds_ib_xmit_atomic(struct rds_connection *conn, struct rm_atomic_op *op) |
15133f6e AG |
723 | { |
724 | struct rds_ib_connection *ic = conn->c_transport_data; | |
725 | struct rds_ib_send_work *send = NULL; | |
726 | struct ib_send_wr *failed_wr; | |
727 | struct rds_ib_device *rds_ibdev; | |
728 | u32 pos; | |
729 | u32 work_alloc; | |
730 | int ret; | |
731 | ||
732 | rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); | |
733 | ||
734 | work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, 1, &pos); | |
735 | if (work_alloc != 1) { | |
736 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
737 | rds_ib_stats_inc(s_ib_tx_ring_full); | |
738 | ret = -ENOMEM; | |
739 | goto out; | |
740 | } | |
741 | ||
742 | /* address of send request in ring */ | |
743 | send = &ic->i_sends[pos]; | |
744 | send->s_queued = jiffies; | |
745 | ||
746 | if (op->op_type == RDS_ATOMIC_TYPE_CSWP) { | |
747 | send->s_wr.opcode = IB_WR_ATOMIC_CMP_AND_SWP; | |
748 | send->s_wr.wr.atomic.compare_add = op->op_compare; | |
749 | send->s_wr.wr.atomic.swap = op->op_swap_add; | |
750 | } else { /* FADD */ | |
751 | send->s_wr.opcode = IB_WR_ATOMIC_FETCH_AND_ADD; | |
752 | send->s_wr.wr.atomic.compare_add = op->op_swap_add; | |
753 | send->s_wr.wr.atomic.swap = 0; | |
754 | } | |
241eef3e | 755 | rds_ib_set_wr_signal_state(ic, send, op->op_notify); |
15133f6e AG |
756 | send->s_wr.num_sge = 1; |
757 | send->s_wr.next = NULL; | |
758 | send->s_wr.wr.atomic.remote_addr = op->op_remote_addr; | |
759 | send->s_wr.wr.atomic.rkey = op->op_rkey; | |
760 | ||
761 | /* map 8 byte retval buffer to the device */ | |
762 | ret = ib_dma_map_sg(ic->i_cm_id->device, op->op_sg, 1, DMA_FROM_DEVICE); | |
763 | rdsdebug("ic %p mapping atomic op %p. mapped %d pg\n", ic, op, ret); | |
764 | if (ret != 1) { | |
765 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
766 | rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); | |
767 | ret = -ENOMEM; /* XXX ? */ | |
768 | goto out; | |
769 | } | |
770 | ||
771 | /* Convert our struct scatterlist to struct ib_sge */ | |
772 | send->s_sge[0].addr = ib_sg_dma_address(ic->i_cm_id->device, op->op_sg); | |
773 | send->s_sge[0].length = ib_sg_dma_len(ic->i_cm_id->device, op->op_sg); | |
774 | send->s_sge[0].lkey = ic->i_mr->lkey; | |
775 | ||
776 | rdsdebug("rva %Lx rpa %Lx len %u\n", op->op_remote_addr, | |
777 | send->s_sge[0].addr, send->s_sge[0].length); | |
778 | ||
779 | failed_wr = &send->s_wr; | |
780 | ret = ib_post_send(ic->i_cm_id->qp, &send->s_wr, &failed_wr); | |
781 | rdsdebug("ic %p send %p (wr %p) ret %d wr %p\n", ic, | |
782 | send, &send->s_wr, ret, failed_wr); | |
783 | BUG_ON(failed_wr != &send->s_wr); | |
784 | if (ret) { | |
785 | printk(KERN_WARNING "RDS/IB: atomic ib_post_send to %pI4 " | |
786 | "returned %d\n", &conn->c_faddr, ret); | |
787 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
788 | goto out; | |
789 | } | |
790 | ||
791 | if (unlikely(failed_wr != &send->s_wr)) { | |
792 | printk(KERN_WARNING "RDS/IB: atomic ib_post_send() rc=%d, but failed_wqe updated!\n", ret); | |
793 | BUG_ON(failed_wr != &send->s_wr); | |
794 | } | |
795 | ||
796 | out: | |
797 | return ret; | |
798 | } | |
799 | ||
f8b3aaf2 | 800 | int rds_ib_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op) |
6a0979df AG |
801 | { |
802 | struct rds_ib_connection *ic = conn->c_transport_data; | |
803 | struct rds_ib_send_work *send = NULL; | |
804 | struct rds_ib_send_work *first; | |
805 | struct rds_ib_send_work *prev; | |
806 | struct ib_send_wr *failed_wr; | |
807 | struct rds_ib_device *rds_ibdev; | |
808 | struct scatterlist *scat; | |
809 | unsigned long len; | |
f8b3aaf2 | 810 | u64 remote_addr = op->op_remote_addr; |
6a0979df AG |
811 | u32 pos; |
812 | u32 work_alloc; | |
813 | u32 i; | |
814 | u32 j; | |
815 | int sent; | |
816 | int ret; | |
817 | int num_sge; | |
818 | ||
819 | rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); | |
820 | ||
ff3d7d36 | 821 | /* map the op the first time we see it */ |
f8b3aaf2 AG |
822 | if (!op->op_mapped) { |
823 | op->op_count = ib_dma_map_sg(ic->i_cm_id->device, | |
824 | op->op_sg, op->op_nents, (op->op_write) ? | |
825 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
826 | rdsdebug("ic %p mapping op %p: %d\n", ic, op, op->op_count); | |
827 | if (op->op_count == 0) { | |
6a0979df AG |
828 | rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); |
829 | ret = -ENOMEM; /* XXX ? */ | |
830 | goto out; | |
831 | } | |
832 | ||
f8b3aaf2 | 833 | op->op_mapped = 1; |
6a0979df AG |
834 | } |
835 | ||
836 | /* | |
837 | * Instead of knowing how to return a partial rdma read/write we insist that there | |
838 | * be enough work requests to send the entire message. | |
839 | */ | |
f8b3aaf2 | 840 | i = ceil(op->op_count, rds_ibdev->max_sge); |
6a0979df AG |
841 | |
842 | work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos); | |
843 | if (work_alloc != i) { | |
844 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
845 | rds_ib_stats_inc(s_ib_tx_ring_full); | |
846 | ret = -ENOMEM; | |
847 | goto out; | |
848 | } | |
849 | ||
850 | send = &ic->i_sends[pos]; | |
851 | first = send; | |
852 | prev = NULL; | |
f8b3aaf2 | 853 | scat = &op->op_sg[0]; |
6a0979df | 854 | sent = 0; |
f8b3aaf2 | 855 | num_sge = op->op_count; |
6a0979df | 856 | |
f8b3aaf2 | 857 | for (i = 0; i < work_alloc && scat != &op->op_sg[op->op_count]; i++) { |
6a0979df AG |
858 | send->s_wr.send_flags = 0; |
859 | send->s_queued = jiffies; | |
241eef3e | 860 | |
f8b3aaf2 | 861 | rds_ib_set_wr_signal_state(ic, send, op->op_notify); |
6a0979df | 862 | |
f8b3aaf2 | 863 | send->s_wr.opcode = op->op_write ? IB_WR_RDMA_WRITE : IB_WR_RDMA_READ; |
6a0979df | 864 | send->s_wr.wr.rdma.remote_addr = remote_addr; |
f8b3aaf2 | 865 | send->s_wr.wr.rdma.rkey = op->op_rkey; |
6a0979df AG |
866 | send->s_op = op; |
867 | ||
868 | if (num_sge > rds_ibdev->max_sge) { | |
869 | send->s_wr.num_sge = rds_ibdev->max_sge; | |
870 | num_sge -= rds_ibdev->max_sge; | |
871 | } else { | |
872 | send->s_wr.num_sge = num_sge; | |
873 | } | |
874 | ||
875 | send->s_wr.next = NULL; | |
876 | ||
877 | if (prev) | |
878 | prev->s_wr.next = &send->s_wr; | |
879 | ||
f8b3aaf2 | 880 | for (j = 0; j < send->s_wr.num_sge && scat != &op->op_sg[op->op_count]; j++) { |
6a0979df AG |
881 | len = ib_sg_dma_len(ic->i_cm_id->device, scat); |
882 | send->s_sge[j].addr = | |
883 | ib_sg_dma_address(ic->i_cm_id->device, scat); | |
884 | send->s_sge[j].length = len; | |
885 | send->s_sge[j].lkey = ic->i_mr->lkey; | |
886 | ||
887 | sent += len; | |
888 | rdsdebug("ic %p sent %d remote_addr %llu\n", ic, sent, remote_addr); | |
889 | ||
890 | remote_addr += len; | |
891 | scat++; | |
892 | } | |
893 | ||
894 | rdsdebug("send %p wr %p num_sge %u next %p\n", send, | |
895 | &send->s_wr, send->s_wr.num_sge, send->s_wr.next); | |
896 | ||
897 | prev = send; | |
898 | if (++send == &ic->i_sends[ic->i_send_ring.w_nr]) | |
899 | send = ic->i_sends; | |
900 | } | |
901 | ||
6a0979df AG |
902 | if (i < work_alloc) { |
903 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i); | |
904 | work_alloc = i; | |
905 | } | |
906 | ||
907 | failed_wr = &first->s_wr; | |
908 | ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr); | |
909 | rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, | |
910 | first, &first->s_wr, ret, failed_wr); | |
911 | BUG_ON(failed_wr != &first->s_wr); | |
912 | if (ret) { | |
913 | printk(KERN_WARNING "RDS/IB: rdma ib_post_send to %pI4 " | |
914 | "returned %d\n", &conn->c_faddr, ret); | |
915 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
916 | goto out; | |
917 | } | |
918 | ||
919 | if (unlikely(failed_wr != &first->s_wr)) { | |
920 | printk(KERN_WARNING "RDS/IB: ib_post_send() rc=%d, but failed_wqe updated!\n", ret); | |
921 | BUG_ON(failed_wr != &first->s_wr); | |
922 | } | |
923 | ||
924 | ||
925 | out: | |
926 | return ret; | |
927 | } | |
928 | ||
929 | void rds_ib_xmit_complete(struct rds_connection *conn) | |
930 | { | |
931 | struct rds_ib_connection *ic = conn->c_transport_data; | |
932 | ||
933 | /* We may have a pending ACK or window update we were unable | |
934 | * to send previously (due to flow control). Try again. */ | |
935 | rds_ib_attempt_ack(ic); | |
936 | } |