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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 | ||
70 | static void rds_ib_send_unmap_rm(struct rds_ib_connection *ic, | |
71 | struct rds_ib_send_work *send, | |
72 | int wc_status) | |
73 | { | |
74 | struct rds_message *rm = send->s_rm; | |
75 | ||
76 | rdsdebug("ic %p send %p rm %p\n", ic, send, rm); | |
77 | ||
78 | ib_dma_unmap_sg(ic->i_cm_id->device, | |
e779137a AG |
79 | rm->data.m_sg, rm->data.m_nents, |
80 | DMA_TO_DEVICE); | |
6a0979df | 81 | |
ff87e97a | 82 | if (rm->rdma.m_rdma_op.r_active) { |
15133f6e AG |
83 | struct rds_rdma_op *op = &rm->rdma.m_rdma_op; |
84 | ||
85 | if (op->r_mapped) { | |
86 | ib_dma_unmap_sg(ic->i_cm_id->device, | |
87 | op->r_sg, op->r_nents, | |
88 | op->r_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
89 | op->r_mapped = 0; | |
90 | } | |
6a0979df AG |
91 | |
92 | /* 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 | * call rds_rdma_send_complete from the cq_handler. 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 | */ | |
9c030391 | 112 | rds_ib_send_complete(rm, wc_status, rds_rdma_send_complete); |
6a0979df | 113 | |
ff87e97a AG |
114 | if (rm->rdma.m_rdma_op.r_write) |
115 | rds_stats_add(s_send_rdma_bytes, rm->rdma.m_rdma_op.r_bytes); | |
6a0979df | 116 | else |
ff87e97a | 117 | rds_stats_add(s_recv_rdma_bytes, rm->rdma.m_rdma_op.r_bytes); |
6a0979df AG |
118 | } |
119 | ||
15133f6e AG |
120 | if (rm->atomic.op_active) { |
121 | struct rm_atomic_op *op = &rm->atomic; | |
122 | ||
123 | /* unmap atomic recvbuf */ | |
124 | if (op->op_mapped) { | |
125 | ib_dma_unmap_sg(ic->i_cm_id->device, op->op_sg, 1, | |
126 | DMA_FROM_DEVICE); | |
127 | op->op_mapped = 0; | |
128 | } | |
129 | ||
9c030391 | 130 | rds_ib_send_complete(rm, wc_status, rds_atomic_send_complete); |
15133f6e AG |
131 | |
132 | if (rm->atomic.op_type == RDS_ATOMIC_TYPE_CSWP) | |
133 | rds_stats_inc(s_atomic_cswp); | |
134 | else | |
135 | rds_stats_inc(s_atomic_fadd); | |
136 | } | |
137 | ||
6a0979df AG |
138 | /* If anyone waited for this message to get flushed out, wake |
139 | * them up now */ | |
140 | rds_message_unmapped(rm); | |
141 | ||
142 | rds_message_put(rm); | |
143 | send->s_rm = NULL; | |
144 | } | |
145 | ||
146 | void rds_ib_send_init_ring(struct rds_ib_connection *ic) | |
147 | { | |
148 | struct rds_ib_send_work *send; | |
149 | u32 i; | |
150 | ||
151 | for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) { | |
152 | struct ib_sge *sge; | |
153 | ||
154 | send->s_rm = NULL; | |
155 | send->s_op = NULL; | |
156 | ||
157 | send->s_wr.wr_id = i; | |
158 | send->s_wr.sg_list = send->s_sge; | |
6a0979df AG |
159 | send->s_wr.ex.imm_data = 0; |
160 | ||
919ced4c | 161 | sge = &send->s_sge[0]; |
6a0979df AG |
162 | sge->addr = ic->i_send_hdrs_dma + (i * sizeof(struct rds_header)); |
163 | sge->length = sizeof(struct rds_header); | |
164 | sge->lkey = ic->i_mr->lkey; | |
919ced4c AG |
165 | |
166 | send->s_sge[1].lkey = ic->i_mr->lkey; | |
6a0979df AG |
167 | } |
168 | } | |
169 | ||
170 | void rds_ib_send_clear_ring(struct rds_ib_connection *ic) | |
171 | { | |
172 | struct rds_ib_send_work *send; | |
173 | u32 i; | |
174 | ||
175 | for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) { | |
15133f6e | 176 | if (!send->s_rm || send->s_wr.opcode == 0xdead) |
6a0979df | 177 | continue; |
15133f6e | 178 | rds_ib_send_unmap_rm(ic, send, IB_WC_WR_FLUSH_ERR); |
6a0979df AG |
179 | } |
180 | } | |
181 | ||
182 | /* | |
183 | * The _oldest/_free ring operations here race cleanly with the alloc/unalloc | |
184 | * operations performed in the send path. As the sender allocs and potentially | |
185 | * unallocs the next free entry in the ring it doesn't alter which is | |
186 | * the next to be freed, which is what this is concerned with. | |
187 | */ | |
188 | void rds_ib_send_cq_comp_handler(struct ib_cq *cq, void *context) | |
189 | { | |
190 | struct rds_connection *conn = context; | |
191 | struct rds_ib_connection *ic = conn->c_transport_data; | |
192 | struct ib_wc wc; | |
193 | struct rds_ib_send_work *send; | |
194 | u32 completed; | |
195 | u32 oldest; | |
196 | u32 i = 0; | |
197 | int ret; | |
198 | ||
199 | rdsdebug("cq %p conn %p\n", cq, conn); | |
200 | rds_ib_stats_inc(s_ib_tx_cq_call); | |
201 | ret = ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); | |
202 | if (ret) | |
203 | rdsdebug("ib_req_notify_cq send failed: %d\n", ret); | |
204 | ||
205 | while (ib_poll_cq(cq, 1, &wc) > 0) { | |
206 | rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n", | |
207 | (unsigned long long)wc.wr_id, wc.status, wc.byte_len, | |
208 | be32_to_cpu(wc.ex.imm_data)); | |
209 | rds_ib_stats_inc(s_ib_tx_cq_event); | |
210 | ||
211 | if (wc.wr_id == RDS_IB_ACK_WR_ID) { | |
212 | if (ic->i_ack_queued + HZ/2 < jiffies) | |
213 | rds_ib_stats_inc(s_ib_tx_stalled); | |
214 | rds_ib_ack_send_complete(ic); | |
215 | continue; | |
216 | } | |
217 | ||
218 | oldest = rds_ib_ring_oldest(&ic->i_send_ring); | |
219 | ||
220 | completed = rds_ib_ring_completed(&ic->i_send_ring, wc.wr_id, oldest); | |
221 | ||
222 | for (i = 0; i < completed; i++) { | |
223 | send = &ic->i_sends[oldest]; | |
224 | ||
225 | /* In the error case, wc.opcode sometimes contains garbage */ | |
226 | switch (send->s_wr.opcode) { | |
227 | case IB_WR_SEND: | |
6a0979df AG |
228 | case IB_WR_RDMA_WRITE: |
229 | case IB_WR_RDMA_READ: | |
15133f6e AG |
230 | case IB_WR_ATOMIC_FETCH_AND_ADD: |
231 | case IB_WR_ATOMIC_CMP_AND_SWP: | |
241eef3e AG |
232 | if (send->s_rm) |
233 | rds_ib_send_unmap_rm(ic, send, wc.status); | |
6a0979df AG |
234 | break; |
235 | default: | |
236 | if (printk_ratelimit()) | |
237 | printk(KERN_NOTICE | |
238 | "RDS/IB: %s: unexpected opcode 0x%x in WR!\n", | |
239 | __func__, send->s_wr.opcode); | |
240 | break; | |
241 | } | |
242 | ||
243 | send->s_wr.opcode = 0xdead; | |
244 | send->s_wr.num_sge = 1; | |
245 | if (send->s_queued + HZ/2 < jiffies) | |
246 | rds_ib_stats_inc(s_ib_tx_stalled); | |
247 | ||
248 | /* If a RDMA operation produced an error, signal this right | |
249 | * away. If we don't, the subsequent SEND that goes with this | |
250 | * RDMA will be canceled with ERR_WFLUSH, and the application | |
251 | * never learn that the RDMA failed. */ | |
252 | if (unlikely(wc.status == IB_WC_REM_ACCESS_ERR && send->s_op)) { | |
253 | struct rds_message *rm; | |
254 | ||
255 | rm = rds_send_get_message(conn, send->s_op); | |
450d06c0 | 256 | if (rm) { |
15133f6e | 257 | rds_ib_send_unmap_rm(ic, send, wc.status); |
9c030391 | 258 | rds_ib_send_complete(rm, wc.status, rds_rdma_send_complete); |
450d06c0 SP |
259 | rds_message_put(rm); |
260 | } | |
6a0979df AG |
261 | } |
262 | ||
263 | oldest = (oldest + 1) % ic->i_send_ring.w_nr; | |
264 | } | |
265 | ||
266 | rds_ib_ring_free(&ic->i_send_ring, completed); | |
267 | ||
f64f9e71 JP |
268 | if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags) || |
269 | test_bit(0, &conn->c_map_queued)) | |
6a0979df AG |
270 | queue_delayed_work(rds_wq, &conn->c_send_w, 0); |
271 | ||
272 | /* We expect errors as the qp is drained during shutdown */ | |
273 | if (wc.status != IB_WC_SUCCESS && rds_conn_up(conn)) { | |
274 | rds_ib_conn_error(conn, | |
275 | "send completion on %pI4 " | |
276 | "had status %u, disconnecting and reconnecting\n", | |
277 | &conn->c_faddr, wc.status); | |
278 | } | |
279 | } | |
280 | } | |
281 | ||
282 | /* | |
283 | * This is the main function for allocating credits when sending | |
284 | * messages. | |
285 | * | |
286 | * Conceptually, we have two counters: | |
287 | * - send credits: this tells us how many WRs we're allowed | |
288 | * to submit without overruning the reciever's queue. For | |
289 | * each SEND WR we post, we decrement this by one. | |
290 | * | |
291 | * - posted credits: this tells us how many WRs we recently | |
292 | * posted to the receive queue. This value is transferred | |
293 | * to the peer as a "credit update" in a RDS header field. | |
294 | * Every time we transmit credits to the peer, we subtract | |
295 | * the amount of transferred credits from this counter. | |
296 | * | |
297 | * It is essential that we avoid situations where both sides have | |
298 | * exhausted their send credits, and are unable to send new credits | |
299 | * to the peer. We achieve this by requiring that we send at least | |
300 | * one credit update to the peer before exhausting our credits. | |
301 | * When new credits arrive, we subtract one credit that is withheld | |
302 | * until we've posted new buffers and are ready to transmit these | |
303 | * credits (see rds_ib_send_add_credits below). | |
304 | * | |
305 | * The RDS send code is essentially single-threaded; rds_send_xmit | |
306 | * grabs c_send_lock to ensure exclusive access to the send ring. | |
307 | * However, the ACK sending code is independent and can race with | |
308 | * message SENDs. | |
309 | * | |
310 | * In the send path, we need to update the counters for send credits | |
311 | * and the counter of posted buffers atomically - when we use the | |
312 | * last available credit, we cannot allow another thread to race us | |
313 | * and grab the posted credits counter. Hence, we have to use a | |
314 | * spinlock to protect the credit counter, or use atomics. | |
315 | * | |
316 | * Spinlocks shared between the send and the receive path are bad, | |
317 | * because they create unnecessary delays. An early implementation | |
318 | * using a spinlock showed a 5% degradation in throughput at some | |
319 | * loads. | |
320 | * | |
321 | * This implementation avoids spinlocks completely, putting both | |
322 | * counters into a single atomic, and updating that atomic using | |
323 | * atomic_add (in the receive path, when receiving fresh credits), | |
324 | * and using atomic_cmpxchg when updating the two counters. | |
325 | */ | |
326 | int rds_ib_send_grab_credits(struct rds_ib_connection *ic, | |
7b70d033 | 327 | u32 wanted, u32 *adv_credits, int need_posted, int max_posted) |
6a0979df AG |
328 | { |
329 | unsigned int avail, posted, got = 0, advertise; | |
330 | long oldval, newval; | |
331 | ||
332 | *adv_credits = 0; | |
333 | if (!ic->i_flowctl) | |
334 | return wanted; | |
335 | ||
336 | try_again: | |
337 | advertise = 0; | |
338 | oldval = newval = atomic_read(&ic->i_credits); | |
339 | posted = IB_GET_POST_CREDITS(oldval); | |
340 | avail = IB_GET_SEND_CREDITS(oldval); | |
341 | ||
342 | rdsdebug("rds_ib_send_grab_credits(%u): credits=%u posted=%u\n", | |
343 | wanted, avail, posted); | |
344 | ||
345 | /* The last credit must be used to send a credit update. */ | |
346 | if (avail && !posted) | |
347 | avail--; | |
348 | ||
349 | if (avail < wanted) { | |
350 | struct rds_connection *conn = ic->i_cm_id->context; | |
351 | ||
352 | /* Oops, there aren't that many credits left! */ | |
353 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); | |
354 | got = avail; | |
355 | } else { | |
356 | /* Sometimes you get what you want, lalala. */ | |
357 | got = wanted; | |
358 | } | |
359 | newval -= IB_SET_SEND_CREDITS(got); | |
360 | ||
361 | /* | |
362 | * If need_posted is non-zero, then the caller wants | |
363 | * the posted regardless of whether any send credits are | |
364 | * available. | |
365 | */ | |
366 | if (posted && (got || need_posted)) { | |
7b70d033 | 367 | advertise = min_t(unsigned int, posted, max_posted); |
6a0979df AG |
368 | newval -= IB_SET_POST_CREDITS(advertise); |
369 | } | |
370 | ||
371 | /* Finally bill everything */ | |
372 | if (atomic_cmpxchg(&ic->i_credits, oldval, newval) != oldval) | |
373 | goto try_again; | |
374 | ||
375 | *adv_credits = advertise; | |
376 | return got; | |
377 | } | |
378 | ||
379 | void rds_ib_send_add_credits(struct rds_connection *conn, unsigned int credits) | |
380 | { | |
381 | struct rds_ib_connection *ic = conn->c_transport_data; | |
382 | ||
383 | if (credits == 0) | |
384 | return; | |
385 | ||
386 | rdsdebug("rds_ib_send_add_credits(%u): current=%u%s\n", | |
387 | credits, | |
388 | IB_GET_SEND_CREDITS(atomic_read(&ic->i_credits)), | |
389 | test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ? ", ll_send_full" : ""); | |
390 | ||
391 | atomic_add(IB_SET_SEND_CREDITS(credits), &ic->i_credits); | |
392 | if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags)) | |
393 | queue_delayed_work(rds_wq, &conn->c_send_w, 0); | |
394 | ||
395 | WARN_ON(IB_GET_SEND_CREDITS(credits) >= 16384); | |
396 | ||
397 | rds_ib_stats_inc(s_ib_rx_credit_updates); | |
398 | } | |
399 | ||
400 | void rds_ib_advertise_credits(struct rds_connection *conn, unsigned int posted) | |
401 | { | |
402 | struct rds_ib_connection *ic = conn->c_transport_data; | |
403 | ||
404 | if (posted == 0) | |
405 | return; | |
406 | ||
407 | atomic_add(IB_SET_POST_CREDITS(posted), &ic->i_credits); | |
408 | ||
409 | /* Decide whether to send an update to the peer now. | |
410 | * If we would send a credit update for every single buffer we | |
411 | * post, we would end up with an ACK storm (ACK arrives, | |
412 | * consumes buffer, we refill the ring, send ACK to remote | |
413 | * advertising the newly posted buffer... ad inf) | |
414 | * | |
415 | * Performance pretty much depends on how often we send | |
416 | * credit updates - too frequent updates mean lots of ACKs. | |
417 | * Too infrequent updates, and the peer will run out of | |
418 | * credits and has to throttle. | |
419 | * For the time being, 16 seems to be a good compromise. | |
420 | */ | |
421 | if (IB_GET_POST_CREDITS(atomic_read(&ic->i_credits)) >= 16) | |
422 | set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags); | |
423 | } | |
424 | ||
241eef3e AG |
425 | static inline void rds_ib_set_wr_signal_state(struct rds_ib_connection *ic, |
426 | struct rds_ib_send_work *send, | |
427 | bool notify) | |
428 | { | |
429 | /* | |
430 | * We want to delay signaling completions just enough to get | |
431 | * the batching benefits but not so much that we create dead time | |
432 | * on the wire. | |
433 | */ | |
434 | if (ic->i_unsignaled_wrs-- == 0 || notify) { | |
435 | ic->i_unsignaled_wrs = rds_ib_sysctl_max_unsig_wrs; | |
436 | send->s_wr.send_flags |= IB_SEND_SIGNALED; | |
437 | } | |
438 | } | |
439 | ||
6a0979df AG |
440 | /* |
441 | * This can be called multiple times for a given message. The first time | |
442 | * we see a message we map its scatterlist into the IB device so that | |
443 | * we can provide that mapped address to the IB scatter gather entries | |
444 | * in the IB work requests. We translate the scatterlist into a series | |
445 | * of work requests that fragment the message. These work requests complete | |
446 | * in order so we pass ownership of the message to the completion handler | |
447 | * once we send the final fragment. | |
448 | * | |
449 | * The RDS core uses the c_send_lock to only enter this function once | |
450 | * per connection. This makes sure that the tx ring alloc/unalloc pairs | |
451 | * don't get out of sync and confuse the ring. | |
452 | */ | |
453 | int rds_ib_xmit(struct rds_connection *conn, struct rds_message *rm, | |
454 | unsigned int hdr_off, unsigned int sg, unsigned int off) | |
455 | { | |
456 | struct rds_ib_connection *ic = conn->c_transport_data; | |
457 | struct ib_device *dev = ic->i_cm_id->device; | |
458 | struct rds_ib_send_work *send = NULL; | |
459 | struct rds_ib_send_work *first; | |
460 | struct rds_ib_send_work *prev; | |
461 | struct ib_send_wr *failed_wr; | |
462 | struct scatterlist *scat; | |
463 | u32 pos; | |
464 | u32 i; | |
465 | u32 work_alloc; | |
da5a06ce | 466 | u32 credit_alloc = 0; |
6a0979df AG |
467 | u32 posted; |
468 | u32 adv_credits = 0; | |
469 | int send_flags = 0; | |
da5a06ce | 470 | int bytes_sent = 0; |
6a0979df AG |
471 | int ret; |
472 | int flow_controlled = 0; | |
473 | ||
474 | BUG_ON(off % RDS_FRAG_SIZE); | |
475 | BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header)); | |
476 | ||
2e7b3b99 AG |
477 | /* Do not send cong updates to IB loopback */ |
478 | if (conn->c_loopback | |
479 | && rm->m_inc.i_hdr.h_flags & RDS_FLAG_CONG_BITMAP) { | |
480 | rds_cong_map_updated(conn->c_fcong, ~(u64) 0); | |
481 | return sizeof(struct rds_header) + RDS_CONG_MAP_BYTES; | |
482 | } | |
483 | ||
6a0979df AG |
484 | /* FIXME we may overallocate here */ |
485 | if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0) | |
486 | i = 1; | |
487 | else | |
488 | i = ceil(be32_to_cpu(rm->m_inc.i_hdr.h_len), RDS_FRAG_SIZE); | |
489 | ||
490 | work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos); | |
491 | if (work_alloc == 0) { | |
492 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); | |
493 | rds_ib_stats_inc(s_ib_tx_ring_full); | |
494 | ret = -ENOMEM; | |
495 | goto out; | |
496 | } | |
497 | ||
6a0979df | 498 | if (ic->i_flowctl) { |
7b70d033 | 499 | credit_alloc = rds_ib_send_grab_credits(ic, work_alloc, &posted, 0, RDS_MAX_ADV_CREDIT); |
6a0979df AG |
500 | adv_credits += posted; |
501 | if (credit_alloc < work_alloc) { | |
502 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - credit_alloc); | |
503 | work_alloc = credit_alloc; | |
c8de3f10 | 504 | flow_controlled = 1; |
6a0979df AG |
505 | } |
506 | if (work_alloc == 0) { | |
d39e0602 | 507 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); |
6a0979df AG |
508 | rds_ib_stats_inc(s_ib_tx_throttle); |
509 | ret = -ENOMEM; | |
510 | goto out; | |
511 | } | |
512 | } | |
513 | ||
514 | /* map the message the first time we see it */ | |
8690bfa1 | 515 | if (!ic->i_rm) { |
e779137a AG |
516 | if (rm->data.m_nents) { |
517 | rm->data.m_count = ib_dma_map_sg(dev, | |
518 | rm->data.m_sg, | |
519 | rm->data.m_nents, | |
520 | DMA_TO_DEVICE); | |
521 | rdsdebug("ic %p mapping rm %p: %d\n", ic, rm, rm->data.m_count); | |
522 | if (rm->data.m_count == 0) { | |
6a0979df AG |
523 | rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); |
524 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
525 | ret = -ENOMEM; /* XXX ? */ | |
526 | goto out; | |
527 | } | |
528 | } else { | |
e779137a | 529 | rm->data.m_count = 0; |
6a0979df AG |
530 | } |
531 | ||
6a0979df AG |
532 | rds_message_addref(rm); |
533 | ic->i_rm = rm; | |
534 | ||
535 | /* Finalize the header */ | |
536 | if (test_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags)) | |
537 | rm->m_inc.i_hdr.h_flags |= RDS_FLAG_ACK_REQUIRED; | |
538 | if (test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) | |
539 | rm->m_inc.i_hdr.h_flags |= RDS_FLAG_RETRANSMITTED; | |
540 | ||
541 | /* If it has a RDMA op, tell the peer we did it. This is | |
542 | * used by the peer to release use-once RDMA MRs. */ | |
ff87e97a | 543 | if (rm->rdma.m_rdma_op.r_active) { |
6a0979df AG |
544 | struct rds_ext_header_rdma ext_hdr; |
545 | ||
ff87e97a | 546 | ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.m_rdma_op.r_key); |
6a0979df AG |
547 | rds_message_add_extension(&rm->m_inc.i_hdr, |
548 | RDS_EXTHDR_RDMA, &ext_hdr, sizeof(ext_hdr)); | |
549 | } | |
550 | if (rm->m_rdma_cookie) { | |
551 | rds_message_add_rdma_dest_extension(&rm->m_inc.i_hdr, | |
552 | rds_rdma_cookie_key(rm->m_rdma_cookie), | |
553 | rds_rdma_cookie_offset(rm->m_rdma_cookie)); | |
554 | } | |
555 | ||
556 | /* Note - rds_ib_piggyb_ack clears the ACK_REQUIRED bit, so | |
557 | * we should not do this unless we have a chance of at least | |
558 | * sticking the header into the send ring. Which is why we | |
559 | * should call rds_ib_ring_alloc first. */ | |
560 | rm->m_inc.i_hdr.h_ack = cpu_to_be64(rds_ib_piggyb_ack(ic)); | |
561 | rds_message_make_checksum(&rm->m_inc.i_hdr); | |
562 | ||
563 | /* | |
564 | * Update adv_credits since we reset the ACK_REQUIRED bit. | |
565 | */ | |
c8de3f10 AG |
566 | if (ic->i_flowctl) { |
567 | rds_ib_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits); | |
568 | adv_credits += posted; | |
569 | BUG_ON(adv_credits > 255); | |
570 | } | |
735f61e6 | 571 | } |
6a0979df | 572 | |
6a0979df AG |
573 | /* Sometimes you want to put a fence between an RDMA |
574 | * READ and the following SEND. | |
575 | * We could either do this all the time | |
576 | * or when requested by the user. Right now, we let | |
577 | * the application choose. | |
578 | */ | |
ff87e97a | 579 | if (rm->rdma.m_rdma_op.r_active && rm->rdma.m_rdma_op.r_fence) |
6a0979df AG |
580 | send_flags = IB_SEND_FENCE; |
581 | ||
da5a06ce AG |
582 | /* Each frag gets a header. Msgs may be 0 bytes */ |
583 | send = &ic->i_sends[pos]; | |
584 | first = send; | |
585 | prev = NULL; | |
586 | scat = &rm->data.m_sg[sg]; | |
587 | i = 0; | |
588 | do { | |
589 | unsigned int len = 0; | |
590 | ||
591 | /* Set up the header */ | |
592 | send->s_wr.send_flags = send_flags; | |
593 | send->s_wr.opcode = IB_WR_SEND; | |
594 | send->s_wr.num_sge = 1; | |
595 | send->s_wr.next = NULL; | |
596 | send->s_queued = jiffies; | |
597 | send->s_op = NULL; | |
6a0979df | 598 | |
da5a06ce AG |
599 | send->s_sge[0].addr = ic->i_send_hdrs_dma |
600 | + (pos * sizeof(struct rds_header)); | |
601 | send->s_sge[0].length = sizeof(struct rds_header); | |
602 | ||
603 | memcpy(&ic->i_send_hdrs[pos], &rm->m_inc.i_hdr, sizeof(struct rds_header)); | |
6a0979df | 604 | |
da5a06ce AG |
605 | /* Set up the data, if present */ |
606 | if (i < work_alloc | |
607 | && scat != &rm->data.m_sg[rm->data.m_count]) { | |
608 | len = min(RDS_FRAG_SIZE, ib_sg_dma_len(dev, scat) - off); | |
609 | send->s_wr.num_sge = 2; | |
6a0979df | 610 | |
da5a06ce AG |
611 | send->s_sge[1].addr = ib_sg_dma_address(dev, scat) + off; |
612 | send->s_sge[1].length = len; | |
6a0979df | 613 | |
da5a06ce AG |
614 | bytes_sent += len; |
615 | off += len; | |
616 | if (off == ib_sg_dma_len(dev, scat)) { | |
617 | scat++; | |
618 | off = 0; | |
619 | } | |
620 | } | |
6a0979df | 621 | |
241eef3e | 622 | rds_ib_set_wr_signal_state(ic, send, 0); |
6a0979df | 623 | |
6a0979df AG |
624 | /* |
625 | * Always signal the last one if we're stopping due to flow control. | |
626 | */ | |
c8de3f10 | 627 | if (ic->i_flowctl && flow_controlled && i == (work_alloc-1)) |
6a0979df AG |
628 | send->s_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; |
629 | ||
630 | rdsdebug("send %p wr %p num_sge %u next %p\n", send, | |
631 | &send->s_wr, send->s_wr.num_sge, send->s_wr.next); | |
632 | ||
c8de3f10 | 633 | if (ic->i_flowctl && adv_credits) { |
6a0979df AG |
634 | struct rds_header *hdr = &ic->i_send_hdrs[pos]; |
635 | ||
636 | /* add credit and redo the header checksum */ | |
637 | hdr->h_credit = adv_credits; | |
638 | rds_message_make_checksum(hdr); | |
639 | adv_credits = 0; | |
640 | rds_ib_stats_inc(s_ib_tx_credit_updates); | |
641 | } | |
642 | ||
643 | if (prev) | |
644 | prev->s_wr.next = &send->s_wr; | |
645 | prev = send; | |
646 | ||
647 | pos = (pos + 1) % ic->i_send_ring.w_nr; | |
da5a06ce AG |
648 | send = &ic->i_sends[pos]; |
649 | i++; | |
650 | ||
651 | } while (i < work_alloc | |
652 | && scat != &rm->data.m_sg[rm->data.m_count]); | |
6a0979df AG |
653 | |
654 | /* Account the RDS header in the number of bytes we sent, but just once. | |
655 | * The caller has no concept of fragmentation. */ | |
656 | if (hdr_off == 0) | |
da5a06ce | 657 | bytes_sent += sizeof(struct rds_header); |
6a0979df AG |
658 | |
659 | /* if we finished the message then send completion owns it */ | |
e779137a | 660 | if (scat == &rm->data.m_sg[rm->data.m_count]) { |
6a0979df | 661 | prev->s_rm = ic->i_rm; |
241eef3e | 662 | prev->s_wr.send_flags |= IB_SEND_SOLICITED; |
6a0979df AG |
663 | ic->i_rm = NULL; |
664 | } | |
665 | ||
da5a06ce | 666 | /* Put back wrs & credits we didn't use */ |
6a0979df AG |
667 | if (i < work_alloc) { |
668 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i); | |
669 | work_alloc = i; | |
670 | } | |
671 | if (ic->i_flowctl && i < credit_alloc) | |
672 | rds_ib_send_add_credits(conn, credit_alloc - i); | |
673 | ||
674 | /* XXX need to worry about failed_wr and partial sends. */ | |
675 | failed_wr = &first->s_wr; | |
676 | ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr); | |
677 | rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, | |
678 | first, &first->s_wr, ret, failed_wr); | |
679 | BUG_ON(failed_wr != &first->s_wr); | |
680 | if (ret) { | |
681 | printk(KERN_WARNING "RDS/IB: ib_post_send to %pI4 " | |
682 | "returned %d\n", &conn->c_faddr, ret); | |
683 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
684 | if (prev->s_rm) { | |
685 | ic->i_rm = prev->s_rm; | |
686 | prev->s_rm = NULL; | |
687 | } | |
735f61e6 AG |
688 | |
689 | rds_ib_conn_error(ic->conn, "ib_post_send failed\n"); | |
6a0979df AG |
690 | goto out; |
691 | } | |
692 | ||
da5a06ce | 693 | ret = bytes_sent; |
6a0979df AG |
694 | out: |
695 | BUG_ON(adv_credits); | |
696 | return ret; | |
697 | } | |
698 | ||
15133f6e AG |
699 | /* |
700 | * Issue atomic operation. | |
701 | * A simplified version of the rdma case, we always map 1 SG, and | |
702 | * only 8 bytes, for the return value from the atomic operation. | |
703 | */ | |
241eef3e | 704 | int rds_ib_xmit_atomic(struct rds_connection *conn, struct rds_message *rm) |
15133f6e AG |
705 | { |
706 | struct rds_ib_connection *ic = conn->c_transport_data; | |
241eef3e | 707 | struct rm_atomic_op *op = &rm->atomic; |
15133f6e AG |
708 | struct rds_ib_send_work *send = NULL; |
709 | struct ib_send_wr *failed_wr; | |
710 | struct rds_ib_device *rds_ibdev; | |
711 | u32 pos; | |
712 | u32 work_alloc; | |
713 | int ret; | |
714 | ||
715 | rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); | |
716 | ||
717 | work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, 1, &pos); | |
718 | if (work_alloc != 1) { | |
719 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
720 | rds_ib_stats_inc(s_ib_tx_ring_full); | |
721 | ret = -ENOMEM; | |
722 | goto out; | |
723 | } | |
724 | ||
725 | /* address of send request in ring */ | |
726 | send = &ic->i_sends[pos]; | |
727 | send->s_queued = jiffies; | |
728 | ||
729 | if (op->op_type == RDS_ATOMIC_TYPE_CSWP) { | |
730 | send->s_wr.opcode = IB_WR_ATOMIC_CMP_AND_SWP; | |
731 | send->s_wr.wr.atomic.compare_add = op->op_compare; | |
732 | send->s_wr.wr.atomic.swap = op->op_swap_add; | |
733 | } else { /* FADD */ | |
734 | send->s_wr.opcode = IB_WR_ATOMIC_FETCH_AND_ADD; | |
735 | send->s_wr.wr.atomic.compare_add = op->op_swap_add; | |
736 | send->s_wr.wr.atomic.swap = 0; | |
737 | } | |
241eef3e | 738 | rds_ib_set_wr_signal_state(ic, send, op->op_notify); |
15133f6e AG |
739 | send->s_wr.num_sge = 1; |
740 | send->s_wr.next = NULL; | |
741 | send->s_wr.wr.atomic.remote_addr = op->op_remote_addr; | |
742 | send->s_wr.wr.atomic.rkey = op->op_rkey; | |
743 | ||
241eef3e AG |
744 | /* |
745 | * If there is no data or rdma ops in the message, then | |
746 | * we must fill in s_rm ourselves, so we properly clean up | |
747 | * on completion. | |
748 | */ | |
749 | if (!rm->rdma.m_rdma_op.r_active && !rm->data.op_active) | |
750 | send->s_rm = rm; | |
751 | ||
15133f6e AG |
752 | /* map 8 byte retval buffer to the device */ |
753 | ret = ib_dma_map_sg(ic->i_cm_id->device, op->op_sg, 1, DMA_FROM_DEVICE); | |
754 | rdsdebug("ic %p mapping atomic op %p. mapped %d pg\n", ic, op, ret); | |
755 | if (ret != 1) { | |
756 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
757 | rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); | |
758 | ret = -ENOMEM; /* XXX ? */ | |
759 | goto out; | |
760 | } | |
761 | ||
762 | /* Convert our struct scatterlist to struct ib_sge */ | |
763 | send->s_sge[0].addr = ib_sg_dma_address(ic->i_cm_id->device, op->op_sg); | |
764 | send->s_sge[0].length = ib_sg_dma_len(ic->i_cm_id->device, op->op_sg); | |
765 | send->s_sge[0].lkey = ic->i_mr->lkey; | |
766 | ||
767 | rdsdebug("rva %Lx rpa %Lx len %u\n", op->op_remote_addr, | |
768 | send->s_sge[0].addr, send->s_sge[0].length); | |
769 | ||
770 | failed_wr = &send->s_wr; | |
771 | ret = ib_post_send(ic->i_cm_id->qp, &send->s_wr, &failed_wr); | |
772 | rdsdebug("ic %p send %p (wr %p) ret %d wr %p\n", ic, | |
773 | send, &send->s_wr, ret, failed_wr); | |
774 | BUG_ON(failed_wr != &send->s_wr); | |
775 | if (ret) { | |
776 | printk(KERN_WARNING "RDS/IB: atomic ib_post_send to %pI4 " | |
777 | "returned %d\n", &conn->c_faddr, ret); | |
778 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
779 | goto out; | |
780 | } | |
781 | ||
782 | if (unlikely(failed_wr != &send->s_wr)) { | |
783 | printk(KERN_WARNING "RDS/IB: atomic ib_post_send() rc=%d, but failed_wqe updated!\n", ret); | |
784 | BUG_ON(failed_wr != &send->s_wr); | |
785 | } | |
786 | ||
787 | out: | |
788 | return ret; | |
789 | } | |
790 | ||
6a0979df AG |
791 | int rds_ib_xmit_rdma(struct rds_connection *conn, struct rds_rdma_op *op) |
792 | { | |
793 | struct rds_ib_connection *ic = conn->c_transport_data; | |
794 | struct rds_ib_send_work *send = NULL; | |
795 | struct rds_ib_send_work *first; | |
796 | struct rds_ib_send_work *prev; | |
797 | struct ib_send_wr *failed_wr; | |
798 | struct rds_ib_device *rds_ibdev; | |
799 | struct scatterlist *scat; | |
800 | unsigned long len; | |
801 | u64 remote_addr = op->r_remote_addr; | |
802 | u32 pos; | |
803 | u32 work_alloc; | |
804 | u32 i; | |
805 | u32 j; | |
806 | int sent; | |
807 | int ret; | |
808 | int num_sge; | |
809 | ||
810 | rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client); | |
811 | ||
812 | /* map the message the first time we see it */ | |
813 | if (!op->r_mapped) { | |
814 | op->r_count = ib_dma_map_sg(ic->i_cm_id->device, | |
815 | op->r_sg, op->r_nents, (op->r_write) ? | |
816 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
817 | rdsdebug("ic %p mapping op %p: %d\n", ic, op, op->r_count); | |
818 | if (op->r_count == 0) { | |
819 | rds_ib_stats_inc(s_ib_tx_sg_mapping_failure); | |
820 | ret = -ENOMEM; /* XXX ? */ | |
821 | goto out; | |
822 | } | |
823 | ||
824 | op->r_mapped = 1; | |
825 | } | |
826 | ||
827 | /* | |
828 | * Instead of knowing how to return a partial rdma read/write we insist that there | |
829 | * be enough work requests to send the entire message. | |
830 | */ | |
831 | i = ceil(op->r_count, rds_ibdev->max_sge); | |
832 | ||
833 | work_alloc = rds_ib_ring_alloc(&ic->i_send_ring, i, &pos); | |
834 | if (work_alloc != i) { | |
835 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
836 | rds_ib_stats_inc(s_ib_tx_ring_full); | |
837 | ret = -ENOMEM; | |
838 | goto out; | |
839 | } | |
840 | ||
841 | send = &ic->i_sends[pos]; | |
842 | first = send; | |
843 | prev = NULL; | |
844 | scat = &op->r_sg[0]; | |
845 | sent = 0; | |
846 | num_sge = op->r_count; | |
847 | ||
848 | for (i = 0; i < work_alloc && scat != &op->r_sg[op->r_count]; i++) { | |
849 | send->s_wr.send_flags = 0; | |
850 | send->s_queued = jiffies; | |
241eef3e AG |
851 | |
852 | rds_ib_set_wr_signal_state(ic, send, op->r_notify); | |
6a0979df AG |
853 | |
854 | send->s_wr.opcode = op->r_write ? IB_WR_RDMA_WRITE : IB_WR_RDMA_READ; | |
855 | send->s_wr.wr.rdma.remote_addr = remote_addr; | |
856 | send->s_wr.wr.rdma.rkey = op->r_key; | |
857 | send->s_op = op; | |
858 | ||
859 | if (num_sge > rds_ibdev->max_sge) { | |
860 | send->s_wr.num_sge = rds_ibdev->max_sge; | |
861 | num_sge -= rds_ibdev->max_sge; | |
862 | } else { | |
863 | send->s_wr.num_sge = num_sge; | |
864 | } | |
865 | ||
866 | send->s_wr.next = NULL; | |
867 | ||
868 | if (prev) | |
869 | prev->s_wr.next = &send->s_wr; | |
870 | ||
871 | for (j = 0; j < send->s_wr.num_sge && scat != &op->r_sg[op->r_count]; j++) { | |
872 | len = ib_sg_dma_len(ic->i_cm_id->device, scat); | |
873 | send->s_sge[j].addr = | |
874 | ib_sg_dma_address(ic->i_cm_id->device, scat); | |
875 | send->s_sge[j].length = len; | |
876 | send->s_sge[j].lkey = ic->i_mr->lkey; | |
877 | ||
878 | sent += len; | |
879 | rdsdebug("ic %p sent %d remote_addr %llu\n", ic, sent, remote_addr); | |
880 | ||
881 | remote_addr += len; | |
882 | scat++; | |
883 | } | |
884 | ||
885 | rdsdebug("send %p wr %p num_sge %u next %p\n", send, | |
886 | &send->s_wr, send->s_wr.num_sge, send->s_wr.next); | |
887 | ||
888 | prev = send; | |
889 | if (++send == &ic->i_sends[ic->i_send_ring.w_nr]) | |
890 | send = ic->i_sends; | |
891 | } | |
892 | ||
6a0979df AG |
893 | if (i < work_alloc) { |
894 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc - i); | |
895 | work_alloc = i; | |
896 | } | |
897 | ||
898 | failed_wr = &first->s_wr; | |
899 | ret = ib_post_send(ic->i_cm_id->qp, &first->s_wr, &failed_wr); | |
900 | rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, | |
901 | first, &first->s_wr, ret, failed_wr); | |
902 | BUG_ON(failed_wr != &first->s_wr); | |
903 | if (ret) { | |
904 | printk(KERN_WARNING "RDS/IB: rdma ib_post_send to %pI4 " | |
905 | "returned %d\n", &conn->c_faddr, ret); | |
906 | rds_ib_ring_unalloc(&ic->i_send_ring, work_alloc); | |
907 | goto out; | |
908 | } | |
909 | ||
910 | if (unlikely(failed_wr != &first->s_wr)) { | |
911 | printk(KERN_WARNING "RDS/IB: ib_post_send() rc=%d, but failed_wqe updated!\n", ret); | |
912 | BUG_ON(failed_wr != &first->s_wr); | |
913 | } | |
914 | ||
915 | ||
916 | out: | |
917 | return ret; | |
918 | } | |
919 | ||
920 | void rds_ib_xmit_complete(struct rds_connection *conn) | |
921 | { | |
922 | struct rds_ib_connection *ic = conn->c_transport_data; | |
923 | ||
924 | /* We may have a pending ACK or window update we were unable | |
925 | * to send previously (due to flow control). Try again. */ | |
926 | rds_ib_attempt_ack(ic); | |
927 | } |