Commit | Line | Data |
---|---|---|
fcd8b7c0 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> | |
cb0a6056 | 37 | #include <linux/ratelimit.h> |
fcd8b7c0 AG |
38 | |
39 | #include "rds.h" | |
fcd8b7c0 AG |
40 | #include "iw.h" |
41 | ||
42 | static void rds_iw_send_rdma_complete(struct rds_message *rm, | |
43 | int wc_status) | |
44 | { | |
45 | int notify_status; | |
46 | ||
47 | switch (wc_status) { | |
48 | case IB_WC_WR_FLUSH_ERR: | |
49 | return; | |
50 | ||
51 | case IB_WC_SUCCESS: | |
52 | notify_status = RDS_RDMA_SUCCESS; | |
53 | break; | |
54 | ||
55 | case IB_WC_REM_ACCESS_ERR: | |
56 | notify_status = RDS_RDMA_REMOTE_ERROR; | |
57 | break; | |
58 | ||
59 | default: | |
60 | notify_status = RDS_RDMA_OTHER_ERROR; | |
61 | break; | |
62 | } | |
63 | rds_rdma_send_complete(rm, notify_status); | |
64 | } | |
65 | ||
66 | static void rds_iw_send_unmap_rdma(struct rds_iw_connection *ic, | |
f8b3aaf2 | 67 | struct rm_rdma_op *op) |
fcd8b7c0 | 68 | { |
f8b3aaf2 | 69 | if (op->op_mapped) { |
fcd8b7c0 | 70 | ib_dma_unmap_sg(ic->i_cm_id->device, |
f8b3aaf2 AG |
71 | op->op_sg, op->op_nents, |
72 | op->op_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
73 | op->op_mapped = 0; | |
fcd8b7c0 AG |
74 | } |
75 | } | |
76 | ||
77 | static void rds_iw_send_unmap_rm(struct rds_iw_connection *ic, | |
78 | struct rds_iw_send_work *send, | |
79 | int wc_status) | |
80 | { | |
81 | struct rds_message *rm = send->s_rm; | |
82 | ||
83 | rdsdebug("ic %p send %p rm %p\n", ic, send, rm); | |
84 | ||
85 | ib_dma_unmap_sg(ic->i_cm_id->device, | |
6c7cc6e4 | 86 | rm->data.op_sg, rm->data.op_nents, |
fcd8b7c0 AG |
87 | DMA_TO_DEVICE); |
88 | ||
f8b3aaf2 AG |
89 | if (rm->rdma.op_active) { |
90 | rds_iw_send_unmap_rdma(ic, &rm->rdma); | |
fcd8b7c0 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 | */ | |
112 | rds_iw_send_rdma_complete(rm, wc_status); | |
113 | ||
f8b3aaf2 AG |
114 | if (rm->rdma.op_write) |
115 | rds_stats_add(s_send_rdma_bytes, rm->rdma.op_bytes); | |
fcd8b7c0 | 116 | else |
f8b3aaf2 | 117 | rds_stats_add(s_recv_rdma_bytes, rm->rdma.op_bytes); |
fcd8b7c0 AG |
118 | } |
119 | ||
120 | /* If anyone waited for this message to get flushed out, wake | |
121 | * them up now */ | |
122 | rds_message_unmapped(rm); | |
123 | ||
124 | rds_message_put(rm); | |
125 | send->s_rm = NULL; | |
126 | } | |
127 | ||
128 | void rds_iw_send_init_ring(struct rds_iw_connection *ic) | |
129 | { | |
130 | struct rds_iw_send_work *send; | |
131 | u32 i; | |
132 | ||
133 | for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) { | |
134 | struct ib_sge *sge; | |
135 | ||
136 | send->s_rm = NULL; | |
137 | send->s_op = NULL; | |
138 | send->s_mapping = NULL; | |
139 | ||
e622f2f4 CH |
140 | send->s_send_wr.next = NULL; |
141 | send->s_send_wr.wr_id = i; | |
142 | send->s_send_wr.sg_list = send->s_sge; | |
143 | send->s_send_wr.num_sge = 1; | |
144 | send->s_send_wr.opcode = IB_WR_SEND; | |
145 | send->s_send_wr.send_flags = 0; | |
146 | send->s_send_wr.ex.imm_data = 0; | |
fcd8b7c0 AG |
147 | |
148 | sge = rds_iw_data_sge(ic, send->s_sge); | |
149 | sge->lkey = 0; | |
150 | ||
151 | sge = rds_iw_header_sge(ic, send->s_sge); | |
152 | sge->addr = ic->i_send_hdrs_dma + (i * sizeof(struct rds_header)); | |
153 | sge->length = sizeof(struct rds_header); | |
154 | sge->lkey = 0; | |
155 | ||
fc279959 SG |
156 | send->s_mr = ib_alloc_mr(ic->i_pd, IB_MR_TYPE_MEM_REG, |
157 | fastreg_message_size); | |
fcd8b7c0 | 158 | if (IS_ERR(send->s_mr)) { |
fc279959 | 159 | printk(KERN_WARNING "RDS/IW: ib_alloc_mr failed\n"); |
fcd8b7c0 AG |
160 | break; |
161 | } | |
fcd8b7c0 AG |
162 | } |
163 | } | |
164 | ||
165 | void rds_iw_send_clear_ring(struct rds_iw_connection *ic) | |
166 | { | |
167 | struct rds_iw_send_work *send; | |
168 | u32 i; | |
169 | ||
170 | for (i = 0, send = ic->i_sends; i < ic->i_send_ring.w_nr; i++, send++) { | |
171 | BUG_ON(!send->s_mr); | |
172 | ib_dereg_mr(send->s_mr); | |
e622f2f4 | 173 | if (send->s_send_wr.opcode == 0xdead) |
fcd8b7c0 AG |
174 | continue; |
175 | if (send->s_rm) | |
176 | rds_iw_send_unmap_rm(ic, send, IB_WC_WR_FLUSH_ERR); | |
177 | if (send->s_op) | |
178 | rds_iw_send_unmap_rdma(ic, send->s_op); | |
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_iw_send_cq_comp_handler(struct ib_cq *cq, void *context) | |
189 | { | |
190 | struct rds_connection *conn = context; | |
191 | struct rds_iw_connection *ic = conn->c_transport_data; | |
192 | struct ib_wc wc; | |
193 | struct rds_iw_send_work *send; | |
194 | u32 completed; | |
195 | u32 oldest; | |
196 | u32 i; | |
197 | int ret; | |
198 | ||
199 | rdsdebug("cq %p conn %p\n", cq, conn); | |
200 | rds_iw_stats_inc(s_iw_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_iw_stats_inc(s_iw_tx_cq_event); | |
210 | ||
211 | if (wc.status != IB_WC_SUCCESS) { | |
212 | printk(KERN_ERR "WC Error: status = %d opcode = %d\n", wc.status, wc.opcode); | |
213 | break; | |
214 | } | |
215 | ||
216 | if (wc.opcode == IB_WC_LOCAL_INV && wc.wr_id == RDS_IW_LOCAL_INV_WR_ID) { | |
217 | ic->i_fastreg_posted = 0; | |
218 | continue; | |
219 | } | |
220 | ||
9ddc8737 | 221 | if (wc.opcode == IB_WC_REG_MR && wc.wr_id == RDS_IW_REG_WR_ID) { |
fcd8b7c0 AG |
222 | ic->i_fastreg_posted = 1; |
223 | continue; | |
224 | } | |
225 | ||
226 | if (wc.wr_id == RDS_IW_ACK_WR_ID) { | |
71fd762f | 227 | if (time_after(jiffies, ic->i_ack_queued + HZ/2)) |
fcd8b7c0 AG |
228 | rds_iw_stats_inc(s_iw_tx_stalled); |
229 | rds_iw_ack_send_complete(ic); | |
230 | continue; | |
231 | } | |
232 | ||
233 | oldest = rds_iw_ring_oldest(&ic->i_send_ring); | |
234 | ||
235 | completed = rds_iw_ring_completed(&ic->i_send_ring, wc.wr_id, oldest); | |
236 | ||
237 | for (i = 0; i < completed; i++) { | |
238 | send = &ic->i_sends[oldest]; | |
239 | ||
240 | /* In the error case, wc.opcode sometimes contains garbage */ | |
e622f2f4 | 241 | switch (send->s_send_wr.opcode) { |
fcd8b7c0 AG |
242 | case IB_WR_SEND: |
243 | if (send->s_rm) | |
244 | rds_iw_send_unmap_rm(ic, send, wc.status); | |
245 | break; | |
9ddc8737 | 246 | case IB_WR_REG_MR: |
fcd8b7c0 AG |
247 | case IB_WR_RDMA_WRITE: |
248 | case IB_WR_RDMA_READ: | |
249 | case IB_WR_RDMA_READ_WITH_INV: | |
250 | /* Nothing to be done - the SG list will be unmapped | |
251 | * when the SEND completes. */ | |
252 | break; | |
253 | default: | |
cb0a6056 | 254 | printk_ratelimited(KERN_NOTICE |
fcd8b7c0 | 255 | "RDS/IW: %s: unexpected opcode 0x%x in WR!\n", |
e622f2f4 | 256 | __func__, send->s_send_wr.opcode); |
fcd8b7c0 AG |
257 | break; |
258 | } | |
259 | ||
e622f2f4 CH |
260 | send->s_send_wr.opcode = 0xdead; |
261 | send->s_send_wr.num_sge = 1; | |
71fd762f | 262 | if (time_after(jiffies, send->s_queued + HZ/2)) |
fcd8b7c0 AG |
263 | rds_iw_stats_inc(s_iw_tx_stalled); |
264 | ||
265 | /* If a RDMA operation produced an error, signal this right | |
266 | * away. If we don't, the subsequent SEND that goes with this | |
267 | * RDMA will be canceled with ERR_WFLUSH, and the application | |
268 | * never learn that the RDMA failed. */ | |
269 | if (unlikely(wc.status == IB_WC_REM_ACCESS_ERR && send->s_op)) { | |
270 | struct rds_message *rm; | |
271 | ||
272 | rm = rds_send_get_message(conn, send->s_op); | |
273 | if (rm) | |
274 | rds_iw_send_rdma_complete(rm, wc.status); | |
275 | } | |
276 | ||
277 | oldest = (oldest + 1) % ic->i_send_ring.w_nr; | |
278 | } | |
279 | ||
280 | rds_iw_ring_free(&ic->i_send_ring, completed); | |
281 | ||
f64f9e71 JP |
282 | if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags) || |
283 | test_bit(0, &conn->c_map_queued)) | |
fcd8b7c0 AG |
284 | queue_delayed_work(rds_wq, &conn->c_send_w, 0); |
285 | ||
286 | /* We expect errors as the qp is drained during shutdown */ | |
287 | if (wc.status != IB_WC_SUCCESS && rds_conn_up(conn)) { | |
288 | rds_iw_conn_error(conn, | |
289 | "send completion on %pI4 " | |
290 | "had status %u, disconnecting and reconnecting\n", | |
291 | &conn->c_faddr, wc.status); | |
292 | } | |
293 | } | |
294 | } | |
295 | ||
296 | /* | |
297 | * This is the main function for allocating credits when sending | |
298 | * messages. | |
299 | * | |
300 | * Conceptually, we have two counters: | |
301 | * - send credits: this tells us how many WRs we're allowed | |
25985edc | 302 | * to submit without overruning the receiver's queue. For |
fcd8b7c0 AG |
303 | * each SEND WR we post, we decrement this by one. |
304 | * | |
305 | * - posted credits: this tells us how many WRs we recently | |
306 | * posted to the receive queue. This value is transferred | |
307 | * to the peer as a "credit update" in a RDS header field. | |
308 | * Every time we transmit credits to the peer, we subtract | |
309 | * the amount of transferred credits from this counter. | |
310 | * | |
311 | * It is essential that we avoid situations where both sides have | |
312 | * exhausted their send credits, and are unable to send new credits | |
313 | * to the peer. We achieve this by requiring that we send at least | |
314 | * one credit update to the peer before exhausting our credits. | |
315 | * When new credits arrive, we subtract one credit that is withheld | |
316 | * until we've posted new buffers and are ready to transmit these | |
317 | * credits (see rds_iw_send_add_credits below). | |
318 | * | |
319 | * The RDS send code is essentially single-threaded; rds_send_xmit | |
320 | * grabs c_send_lock to ensure exclusive access to the send ring. | |
321 | * However, the ACK sending code is independent and can race with | |
322 | * message SENDs. | |
323 | * | |
324 | * In the send path, we need to update the counters for send credits | |
325 | * and the counter of posted buffers atomically - when we use the | |
326 | * last available credit, we cannot allow another thread to race us | |
327 | * and grab the posted credits counter. Hence, we have to use a | |
328 | * spinlock to protect the credit counter, or use atomics. | |
329 | * | |
330 | * Spinlocks shared between the send and the receive path are bad, | |
331 | * because they create unnecessary delays. An early implementation | |
332 | * using a spinlock showed a 5% degradation in throughput at some | |
333 | * loads. | |
334 | * | |
335 | * This implementation avoids spinlocks completely, putting both | |
336 | * counters into a single atomic, and updating that atomic using | |
337 | * atomic_add (in the receive path, when receiving fresh credits), | |
338 | * and using atomic_cmpxchg when updating the two counters. | |
339 | */ | |
340 | int rds_iw_send_grab_credits(struct rds_iw_connection *ic, | |
7b70d033 | 341 | u32 wanted, u32 *adv_credits, int need_posted, int max_posted) |
fcd8b7c0 AG |
342 | { |
343 | unsigned int avail, posted, got = 0, advertise; | |
344 | long oldval, newval; | |
345 | ||
346 | *adv_credits = 0; | |
347 | if (!ic->i_flowctl) | |
348 | return wanted; | |
349 | ||
350 | try_again: | |
351 | advertise = 0; | |
352 | oldval = newval = atomic_read(&ic->i_credits); | |
353 | posted = IB_GET_POST_CREDITS(oldval); | |
354 | avail = IB_GET_SEND_CREDITS(oldval); | |
355 | ||
11ac1199 | 356 | rdsdebug("wanted=%u credits=%u posted=%u\n", |
fcd8b7c0 AG |
357 | wanted, avail, posted); |
358 | ||
359 | /* The last credit must be used to send a credit update. */ | |
360 | if (avail && !posted) | |
361 | avail--; | |
362 | ||
363 | if (avail < wanted) { | |
364 | struct rds_connection *conn = ic->i_cm_id->context; | |
365 | ||
366 | /* Oops, there aren't that many credits left! */ | |
367 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); | |
368 | got = avail; | |
369 | } else { | |
370 | /* Sometimes you get what you want, lalala. */ | |
371 | got = wanted; | |
372 | } | |
373 | newval -= IB_SET_SEND_CREDITS(got); | |
374 | ||
375 | /* | |
376 | * If need_posted is non-zero, then the caller wants | |
377 | * the posted regardless of whether any send credits are | |
378 | * available. | |
379 | */ | |
380 | if (posted && (got || need_posted)) { | |
7b70d033 | 381 | advertise = min_t(unsigned int, posted, max_posted); |
fcd8b7c0 AG |
382 | newval -= IB_SET_POST_CREDITS(advertise); |
383 | } | |
384 | ||
385 | /* Finally bill everything */ | |
386 | if (atomic_cmpxchg(&ic->i_credits, oldval, newval) != oldval) | |
387 | goto try_again; | |
388 | ||
389 | *adv_credits = advertise; | |
390 | return got; | |
391 | } | |
392 | ||
393 | void rds_iw_send_add_credits(struct rds_connection *conn, unsigned int credits) | |
394 | { | |
395 | struct rds_iw_connection *ic = conn->c_transport_data; | |
396 | ||
397 | if (credits == 0) | |
398 | return; | |
399 | ||
11ac1199 | 400 | rdsdebug("credits=%u current=%u%s\n", |
fcd8b7c0 AG |
401 | credits, |
402 | IB_GET_SEND_CREDITS(atomic_read(&ic->i_credits)), | |
403 | test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ? ", ll_send_full" : ""); | |
404 | ||
405 | atomic_add(IB_SET_SEND_CREDITS(credits), &ic->i_credits); | |
406 | if (test_and_clear_bit(RDS_LL_SEND_FULL, &conn->c_flags)) | |
407 | queue_delayed_work(rds_wq, &conn->c_send_w, 0); | |
408 | ||
409 | WARN_ON(IB_GET_SEND_CREDITS(credits) >= 16384); | |
410 | ||
411 | rds_iw_stats_inc(s_iw_rx_credit_updates); | |
412 | } | |
413 | ||
414 | void rds_iw_advertise_credits(struct rds_connection *conn, unsigned int posted) | |
415 | { | |
416 | struct rds_iw_connection *ic = conn->c_transport_data; | |
417 | ||
418 | if (posted == 0) | |
419 | return; | |
420 | ||
421 | atomic_add(IB_SET_POST_CREDITS(posted), &ic->i_credits); | |
422 | ||
423 | /* Decide whether to send an update to the peer now. | |
424 | * If we would send a credit update for every single buffer we | |
425 | * post, we would end up with an ACK storm (ACK arrives, | |
426 | * consumes buffer, we refill the ring, send ACK to remote | |
427 | * advertising the newly posted buffer... ad inf) | |
428 | * | |
429 | * Performance pretty much depends on how often we send | |
430 | * credit updates - too frequent updates mean lots of ACKs. | |
431 | * Too infrequent updates, and the peer will run out of | |
432 | * credits and has to throttle. | |
433 | * For the time being, 16 seems to be a good compromise. | |
434 | */ | |
435 | if (IB_GET_POST_CREDITS(atomic_read(&ic->i_credits)) >= 16) | |
436 | set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags); | |
437 | } | |
438 | ||
439 | static inline void | |
440 | rds_iw_xmit_populate_wr(struct rds_iw_connection *ic, | |
441 | struct rds_iw_send_work *send, unsigned int pos, | |
442 | unsigned long buffer, unsigned int length, | |
443 | int send_flags) | |
444 | { | |
445 | struct ib_sge *sge; | |
446 | ||
447 | WARN_ON(pos != send - ic->i_sends); | |
448 | ||
e622f2f4 CH |
449 | send->s_send_wr.send_flags = send_flags; |
450 | send->s_send_wr.opcode = IB_WR_SEND; | |
451 | send->s_send_wr.num_sge = 2; | |
452 | send->s_send_wr.next = NULL; | |
fcd8b7c0 AG |
453 | send->s_queued = jiffies; |
454 | send->s_op = NULL; | |
455 | ||
456 | if (length != 0) { | |
457 | sge = rds_iw_data_sge(ic, send->s_sge); | |
458 | sge->addr = buffer; | |
459 | sge->length = length; | |
460 | sge->lkey = rds_iw_local_dma_lkey(ic); | |
461 | ||
462 | sge = rds_iw_header_sge(ic, send->s_sge); | |
463 | } else { | |
464 | /* We're sending a packet with no payload. There is only | |
465 | * one SGE */ | |
e622f2f4 | 466 | send->s_send_wr.num_sge = 1; |
fcd8b7c0 AG |
467 | sge = &send->s_sge[0]; |
468 | } | |
469 | ||
470 | sge->addr = ic->i_send_hdrs_dma + (pos * sizeof(struct rds_header)); | |
471 | sge->length = sizeof(struct rds_header); | |
472 | sge->lkey = rds_iw_local_dma_lkey(ic); | |
473 | } | |
474 | ||
475 | /* | |
476 | * This can be called multiple times for a given message. The first time | |
477 | * we see a message we map its scatterlist into the IB device so that | |
478 | * we can provide that mapped address to the IB scatter gather entries | |
479 | * in the IB work requests. We translate the scatterlist into a series | |
480 | * of work requests that fragment the message. These work requests complete | |
481 | * in order so we pass ownership of the message to the completion handler | |
482 | * once we send the final fragment. | |
483 | * | |
484 | * The RDS core uses the c_send_lock to only enter this function once | |
485 | * per connection. This makes sure that the tx ring alloc/unalloc pairs | |
486 | * don't get out of sync and confuse the ring. | |
487 | */ | |
488 | int rds_iw_xmit(struct rds_connection *conn, struct rds_message *rm, | |
489 | unsigned int hdr_off, unsigned int sg, unsigned int off) | |
490 | { | |
491 | struct rds_iw_connection *ic = conn->c_transport_data; | |
492 | struct ib_device *dev = ic->i_cm_id->device; | |
493 | struct rds_iw_send_work *send = NULL; | |
494 | struct rds_iw_send_work *first; | |
495 | struct rds_iw_send_work *prev; | |
496 | struct ib_send_wr *failed_wr; | |
497 | struct scatterlist *scat; | |
498 | u32 pos; | |
499 | u32 i; | |
500 | u32 work_alloc; | |
501 | u32 credit_alloc; | |
502 | u32 posted; | |
503 | u32 adv_credits = 0; | |
504 | int send_flags = 0; | |
505 | int sent; | |
506 | int ret; | |
507 | int flow_controlled = 0; | |
508 | ||
509 | BUG_ON(off % RDS_FRAG_SIZE); | |
510 | BUG_ON(hdr_off != 0 && hdr_off != sizeof(struct rds_header)); | |
511 | ||
512 | /* Fastreg support */ | |
f64f9e71 | 513 | if (rds_rdma_cookie_key(rm->m_rdma_cookie) && !ic->i_fastreg_posted) { |
fcd8b7c0 AG |
514 | ret = -EAGAIN; |
515 | goto out; | |
516 | } | |
517 | ||
518 | /* FIXME we may overallocate here */ | |
519 | if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0) | |
520 | i = 1; | |
521 | else | |
522 | i = ceil(be32_to_cpu(rm->m_inc.i_hdr.h_len), RDS_FRAG_SIZE); | |
523 | ||
524 | work_alloc = rds_iw_ring_alloc(&ic->i_send_ring, i, &pos); | |
525 | if (work_alloc == 0) { | |
526 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); | |
527 | rds_iw_stats_inc(s_iw_tx_ring_full); | |
528 | ret = -ENOMEM; | |
529 | goto out; | |
530 | } | |
531 | ||
532 | credit_alloc = work_alloc; | |
533 | if (ic->i_flowctl) { | |
7b70d033 | 534 | credit_alloc = rds_iw_send_grab_credits(ic, work_alloc, &posted, 0, RDS_MAX_ADV_CREDIT); |
fcd8b7c0 AG |
535 | adv_credits += posted; |
536 | if (credit_alloc < work_alloc) { | |
537 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc - credit_alloc); | |
538 | work_alloc = credit_alloc; | |
539 | flow_controlled++; | |
540 | } | |
541 | if (work_alloc == 0) { | |
d39e0602 | 542 | set_bit(RDS_LL_SEND_FULL, &conn->c_flags); |
fcd8b7c0 AG |
543 | rds_iw_stats_inc(s_iw_tx_throttle); |
544 | ret = -ENOMEM; | |
545 | goto out; | |
546 | } | |
547 | } | |
548 | ||
549 | /* map the message the first time we see it */ | |
8690bfa1 | 550 | if (!ic->i_rm) { |
fcd8b7c0 AG |
551 | /* |
552 | printk(KERN_NOTICE "rds_iw_xmit prep msg dport=%u flags=0x%x len=%d\n", | |
553 | be16_to_cpu(rm->m_inc.i_hdr.h_dport), | |
554 | rm->m_inc.i_hdr.h_flags, | |
555 | be32_to_cpu(rm->m_inc.i_hdr.h_len)); | |
556 | */ | |
6c7cc6e4 AG |
557 | if (rm->data.op_nents) { |
558 | rm->data.op_count = ib_dma_map_sg(dev, | |
559 | rm->data.op_sg, | |
560 | rm->data.op_nents, | |
561 | DMA_TO_DEVICE); | |
562 | rdsdebug("ic %p mapping rm %p: %d\n", ic, rm, rm->data.op_count); | |
563 | if (rm->data.op_count == 0) { | |
fcd8b7c0 AG |
564 | rds_iw_stats_inc(s_iw_tx_sg_mapping_failure); |
565 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); | |
566 | ret = -ENOMEM; /* XXX ? */ | |
567 | goto out; | |
568 | } | |
569 | } else { | |
6c7cc6e4 | 570 | rm->data.op_count = 0; |
fcd8b7c0 AG |
571 | } |
572 | ||
573 | ic->i_unsignaled_wrs = rds_iw_sysctl_max_unsig_wrs; | |
574 | ic->i_unsignaled_bytes = rds_iw_sysctl_max_unsig_bytes; | |
575 | rds_message_addref(rm); | |
d655a9fb WW |
576 | rm->data.op_dmasg = 0; |
577 | rm->data.op_dmaoff = 0; | |
fcd8b7c0 AG |
578 | ic->i_rm = rm; |
579 | ||
580 | /* Finalize the header */ | |
581 | if (test_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags)) | |
582 | rm->m_inc.i_hdr.h_flags |= RDS_FLAG_ACK_REQUIRED; | |
583 | if (test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) | |
584 | rm->m_inc.i_hdr.h_flags |= RDS_FLAG_RETRANSMITTED; | |
585 | ||
586 | /* If it has a RDMA op, tell the peer we did it. This is | |
587 | * used by the peer to release use-once RDMA MRs. */ | |
f8b3aaf2 | 588 | if (rm->rdma.op_active) { |
fcd8b7c0 AG |
589 | struct rds_ext_header_rdma ext_hdr; |
590 | ||
f8b3aaf2 | 591 | ext_hdr.h_rdma_rkey = cpu_to_be32(rm->rdma.op_rkey); |
fcd8b7c0 AG |
592 | rds_message_add_extension(&rm->m_inc.i_hdr, |
593 | RDS_EXTHDR_RDMA, &ext_hdr, sizeof(ext_hdr)); | |
594 | } | |
595 | if (rm->m_rdma_cookie) { | |
596 | rds_message_add_rdma_dest_extension(&rm->m_inc.i_hdr, | |
597 | rds_rdma_cookie_key(rm->m_rdma_cookie), | |
598 | rds_rdma_cookie_offset(rm->m_rdma_cookie)); | |
599 | } | |
600 | ||
601 | /* Note - rds_iw_piggyb_ack clears the ACK_REQUIRED bit, so | |
602 | * we should not do this unless we have a chance of at least | |
603 | * sticking the header into the send ring. Which is why we | |
604 | * should call rds_iw_ring_alloc first. */ | |
605 | rm->m_inc.i_hdr.h_ack = cpu_to_be64(rds_iw_piggyb_ack(ic)); | |
606 | rds_message_make_checksum(&rm->m_inc.i_hdr); | |
607 | ||
608 | /* | |
609 | * Update adv_credits since we reset the ACK_REQUIRED bit. | |
610 | */ | |
7b70d033 | 611 | rds_iw_send_grab_credits(ic, 0, &posted, 1, RDS_MAX_ADV_CREDIT - adv_credits); |
fcd8b7c0 AG |
612 | adv_credits += posted; |
613 | BUG_ON(adv_credits > 255); | |
735f61e6 | 614 | } |
fcd8b7c0 AG |
615 | |
616 | send = &ic->i_sends[pos]; | |
617 | first = send; | |
618 | prev = NULL; | |
d655a9fb | 619 | scat = &rm->data.op_sg[rm->data.op_dmasg]; |
fcd8b7c0 AG |
620 | sent = 0; |
621 | i = 0; | |
622 | ||
623 | /* Sometimes you want to put a fence between an RDMA | |
624 | * READ and the following SEND. | |
625 | * We could either do this all the time | |
626 | * or when requested by the user. Right now, we let | |
627 | * the application choose. | |
628 | */ | |
f8b3aaf2 | 629 | if (rm->rdma.op_active && rm->rdma.op_fence) |
fcd8b7c0 AG |
630 | send_flags = IB_SEND_FENCE; |
631 | ||
632 | /* | |
633 | * We could be copying the header into the unused tail of the page. | |
634 | * That would need to be changed in the future when those pages might | |
635 | * be mapped userspace pages or page cache pages. So instead we always | |
636 | * use a second sge and our long-lived ring of mapped headers. We send | |
637 | * the header after the data so that the data payload can be aligned on | |
638 | * the receiver. | |
639 | */ | |
640 | ||
641 | /* handle a 0-len message */ | |
642 | if (be32_to_cpu(rm->m_inc.i_hdr.h_len) == 0) { | |
643 | rds_iw_xmit_populate_wr(ic, send, pos, 0, 0, send_flags); | |
644 | goto add_header; | |
645 | } | |
646 | ||
647 | /* if there's data reference it with a chain of work reqs */ | |
6c7cc6e4 | 648 | for (; i < work_alloc && scat != &rm->data.op_sg[rm->data.op_count]; i++) { |
fcd8b7c0 AG |
649 | unsigned int len; |
650 | ||
651 | send = &ic->i_sends[pos]; | |
652 | ||
d655a9fb WW |
653 | len = min(RDS_FRAG_SIZE, |
654 | ib_sg_dma_len(dev, scat) - rm->data.op_dmaoff); | |
fcd8b7c0 | 655 | rds_iw_xmit_populate_wr(ic, send, pos, |
d655a9fb WW |
656 | ib_sg_dma_address(dev, scat) + rm->data.op_dmaoff, len, |
657 | send_flags); | |
fcd8b7c0 AG |
658 | |
659 | /* | |
660 | * We want to delay signaling completions just enough to get | |
661 | * the batching benefits but not so much that we create dead time | |
662 | * on the wire. | |
663 | */ | |
664 | if (ic->i_unsignaled_wrs-- == 0) { | |
665 | ic->i_unsignaled_wrs = rds_iw_sysctl_max_unsig_wrs; | |
e622f2f4 | 666 | send->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; |
fcd8b7c0 AG |
667 | } |
668 | ||
669 | ic->i_unsignaled_bytes -= len; | |
670 | if (ic->i_unsignaled_bytes <= 0) { | |
671 | ic->i_unsignaled_bytes = rds_iw_sysctl_max_unsig_bytes; | |
e622f2f4 | 672 | send->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; |
fcd8b7c0 AG |
673 | } |
674 | ||
675 | /* | |
676 | * Always signal the last one if we're stopping due to flow control. | |
677 | */ | |
678 | if (flow_controlled && i == (work_alloc-1)) | |
e622f2f4 | 679 | send->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; |
fcd8b7c0 AG |
680 | |
681 | rdsdebug("send %p wr %p num_sge %u next %p\n", send, | |
e622f2f4 | 682 | &send->s_send_wr, send->s_send_wr.num_sge, send->s_send_wr.next); |
fcd8b7c0 AG |
683 | |
684 | sent += len; | |
d655a9fb WW |
685 | rm->data.op_dmaoff += len; |
686 | if (rm->data.op_dmaoff == ib_sg_dma_len(dev, scat)) { | |
fcd8b7c0 | 687 | scat++; |
d655a9fb WW |
688 | rm->data.op_dmaoff = 0; |
689 | rm->data.op_dmasg++; | |
fcd8b7c0 AG |
690 | } |
691 | ||
692 | add_header: | |
693 | /* Tack on the header after the data. The header SGE should already | |
694 | * have been set up to point to the right header buffer. */ | |
695 | memcpy(&ic->i_send_hdrs[pos], &rm->m_inc.i_hdr, sizeof(struct rds_header)); | |
696 | ||
697 | if (0) { | |
698 | struct rds_header *hdr = &ic->i_send_hdrs[pos]; | |
699 | ||
700 | printk(KERN_NOTICE "send WR dport=%u flags=0x%x len=%d\n", | |
701 | be16_to_cpu(hdr->h_dport), | |
702 | hdr->h_flags, | |
703 | be32_to_cpu(hdr->h_len)); | |
704 | } | |
705 | if (adv_credits) { | |
706 | struct rds_header *hdr = &ic->i_send_hdrs[pos]; | |
707 | ||
708 | /* add credit and redo the header checksum */ | |
709 | hdr->h_credit = adv_credits; | |
710 | rds_message_make_checksum(hdr); | |
711 | adv_credits = 0; | |
712 | rds_iw_stats_inc(s_iw_tx_credit_updates); | |
713 | } | |
714 | ||
715 | if (prev) | |
e622f2f4 | 716 | prev->s_send_wr.next = &send->s_send_wr; |
fcd8b7c0 AG |
717 | prev = send; |
718 | ||
719 | pos = (pos + 1) % ic->i_send_ring.w_nr; | |
720 | } | |
721 | ||
722 | /* Account the RDS header in the number of bytes we sent, but just once. | |
723 | * The caller has no concept of fragmentation. */ | |
724 | if (hdr_off == 0) | |
725 | sent += sizeof(struct rds_header); | |
726 | ||
727 | /* if we finished the message then send completion owns it */ | |
6c7cc6e4 | 728 | if (scat == &rm->data.op_sg[rm->data.op_count]) { |
fcd8b7c0 | 729 | prev->s_rm = ic->i_rm; |
e622f2f4 | 730 | prev->s_send_wr.send_flags |= IB_SEND_SIGNALED | IB_SEND_SOLICITED; |
fcd8b7c0 AG |
731 | ic->i_rm = NULL; |
732 | } | |
733 | ||
734 | if (i < work_alloc) { | |
735 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc - i); | |
736 | work_alloc = i; | |
737 | } | |
738 | if (ic->i_flowctl && i < credit_alloc) | |
739 | rds_iw_send_add_credits(conn, credit_alloc - i); | |
740 | ||
741 | /* XXX need to worry about failed_wr and partial sends. */ | |
e622f2f4 CH |
742 | failed_wr = &first->s_send_wr; |
743 | ret = ib_post_send(ic->i_cm_id->qp, &first->s_send_wr, &failed_wr); | |
fcd8b7c0 | 744 | rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, |
e622f2f4 CH |
745 | first, &first->s_send_wr, ret, failed_wr); |
746 | BUG_ON(failed_wr != &first->s_send_wr); | |
fcd8b7c0 AG |
747 | if (ret) { |
748 | printk(KERN_WARNING "RDS/IW: ib_post_send to %pI4 " | |
749 | "returned %d\n", &conn->c_faddr, ret); | |
750 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); | |
751 | if (prev->s_rm) { | |
752 | ic->i_rm = prev->s_rm; | |
753 | prev->s_rm = NULL; | |
754 | } | |
755 | goto out; | |
756 | } | |
757 | ||
758 | ret = sent; | |
759 | out: | |
760 | BUG_ON(adv_credits); | |
761 | return ret; | |
762 | } | |
763 | ||
9ddc8737 SG |
764 | static int rds_iw_build_send_reg(struct rds_iw_send_work *send, |
765 | struct scatterlist *sg, | |
766 | int sg_nents) | |
fcd8b7c0 | 767 | { |
9ddc8737 SG |
768 | int n; |
769 | ||
770 | n = ib_map_mr_sg(send->s_mr, sg, sg_nents, PAGE_SIZE); | |
771 | if (unlikely(n != sg_nents)) | |
772 | return n < 0 ? n : -EINVAL; | |
773 | ||
774 | send->s_reg_wr.wr.opcode = IB_WR_REG_MR; | |
775 | send->s_reg_wr.wr.wr_id = 0; | |
776 | send->s_reg_wr.wr.num_sge = 0; | |
777 | send->s_reg_wr.mr = send->s_mr; | |
778 | send->s_reg_wr.key = send->s_mr->rkey; | |
779 | send->s_reg_wr.access = IB_ACCESS_REMOTE_WRITE; | |
fcd8b7c0 AG |
780 | |
781 | ib_update_fast_reg_key(send->s_mr, send->s_remap_count++); | |
9ddc8737 SG |
782 | |
783 | return 0; | |
fcd8b7c0 AG |
784 | } |
785 | ||
f8b3aaf2 | 786 | int rds_iw_xmit_rdma(struct rds_connection *conn, struct rm_rdma_op *op) |
fcd8b7c0 AG |
787 | { |
788 | struct rds_iw_connection *ic = conn->c_transport_data; | |
789 | struct rds_iw_send_work *send = NULL; | |
790 | struct rds_iw_send_work *first; | |
791 | struct rds_iw_send_work *prev; | |
792 | struct ib_send_wr *failed_wr; | |
793 | struct rds_iw_device *rds_iwdev; | |
794 | struct scatterlist *scat; | |
795 | unsigned long len; | |
f8b3aaf2 | 796 | u64 remote_addr = op->op_remote_addr; |
fcd8b7c0 AG |
797 | u32 pos, fr_pos; |
798 | u32 work_alloc; | |
799 | u32 i; | |
800 | u32 j; | |
801 | int sent; | |
802 | int ret; | |
803 | int num_sge; | |
9ddc8737 | 804 | int sg_nents; |
fcd8b7c0 AG |
805 | |
806 | rds_iwdev = ib_get_client_data(ic->i_cm_id->device, &rds_iw_client); | |
807 | ||
808 | /* map the message the first time we see it */ | |
f8b3aaf2 AG |
809 | if (!op->op_mapped) { |
810 | op->op_count = ib_dma_map_sg(ic->i_cm_id->device, | |
811 | op->op_sg, op->op_nents, (op->op_write) ? | |
812 | DMA_TO_DEVICE : DMA_FROM_DEVICE); | |
813 | rdsdebug("ic %p mapping op %p: %d\n", ic, op, op->op_count); | |
814 | if (op->op_count == 0) { | |
fcd8b7c0 AG |
815 | rds_iw_stats_inc(s_iw_tx_sg_mapping_failure); |
816 | ret = -ENOMEM; /* XXX ? */ | |
817 | goto out; | |
818 | } | |
819 | ||
f8b3aaf2 | 820 | op->op_mapped = 1; |
fcd8b7c0 AG |
821 | } |
822 | ||
f8b3aaf2 | 823 | if (!op->op_write) { |
fcd8b7c0 AG |
824 | /* Alloc space on the send queue for the fastreg */ |
825 | work_alloc = rds_iw_ring_alloc(&ic->i_send_ring, 1, &fr_pos); | |
826 | if (work_alloc != 1) { | |
827 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); | |
828 | rds_iw_stats_inc(s_iw_tx_ring_full); | |
829 | ret = -ENOMEM; | |
830 | goto out; | |
831 | } | |
832 | } | |
833 | ||
834 | /* | |
835 | * Instead of knowing how to return a partial rdma read/write we insist that there | |
836 | * be enough work requests to send the entire message. | |
837 | */ | |
f8b3aaf2 | 838 | i = ceil(op->op_count, rds_iwdev->max_sge); |
fcd8b7c0 AG |
839 | |
840 | work_alloc = rds_iw_ring_alloc(&ic->i_send_ring, i, &pos); | |
841 | if (work_alloc != i) { | |
842 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); | |
843 | rds_iw_stats_inc(s_iw_tx_ring_full); | |
844 | ret = -ENOMEM; | |
845 | goto out; | |
846 | } | |
847 | ||
848 | send = &ic->i_sends[pos]; | |
f8b3aaf2 | 849 | if (!op->op_write) { |
fcd8b7c0 AG |
850 | first = prev = &ic->i_sends[fr_pos]; |
851 | } else { | |
852 | first = send; | |
853 | prev = NULL; | |
854 | } | |
f8b3aaf2 | 855 | scat = &op->op_sg[0]; |
fcd8b7c0 | 856 | sent = 0; |
f8b3aaf2 | 857 | num_sge = op->op_count; |
9ddc8737 | 858 | sg_nents = 0; |
fcd8b7c0 | 859 | |
f8b3aaf2 | 860 | for (i = 0; i < work_alloc && scat != &op->op_sg[op->op_count]; i++) { |
e622f2f4 | 861 | send->s_rdma_wr.wr.send_flags = 0; |
fcd8b7c0 AG |
862 | send->s_queued = jiffies; |
863 | ||
864 | /* | |
865 | * We want to delay signaling completions just enough to get | |
866 | * the batching benefits but not so much that we create dead time on the wire. | |
867 | */ | |
868 | if (ic->i_unsignaled_wrs-- == 0) { | |
869 | ic->i_unsignaled_wrs = rds_iw_sysctl_max_unsig_wrs; | |
e622f2f4 | 870 | send->s_rdma_wr.wr.send_flags = IB_SEND_SIGNALED; |
fcd8b7c0 AG |
871 | } |
872 | ||
873 | /* To avoid the need to have the plumbing to invalidate the fastreg_mr used | |
874 | * for local access after RDS is finished with it, using | |
875 | * IB_WR_RDMA_READ_WITH_INV will invalidate it after the read has completed. | |
876 | */ | |
f8b3aaf2 | 877 | if (op->op_write) |
e622f2f4 | 878 | send->s_rdma_wr.wr.opcode = IB_WR_RDMA_WRITE; |
fcd8b7c0 | 879 | else |
e622f2f4 | 880 | send->s_rdma_wr.wr.opcode = IB_WR_RDMA_READ_WITH_INV; |
fcd8b7c0 | 881 | |
e622f2f4 CH |
882 | send->s_rdma_wr.remote_addr = remote_addr; |
883 | send->s_rdma_wr.rkey = op->op_rkey; | |
fcd8b7c0 AG |
884 | send->s_op = op; |
885 | ||
886 | if (num_sge > rds_iwdev->max_sge) { | |
e622f2f4 | 887 | send->s_rdma_wr.wr.num_sge = rds_iwdev->max_sge; |
fcd8b7c0 AG |
888 | num_sge -= rds_iwdev->max_sge; |
889 | } else | |
e622f2f4 | 890 | send->s_rdma_wr.wr.num_sge = num_sge; |
fcd8b7c0 | 891 | |
e622f2f4 | 892 | send->s_rdma_wr.wr.next = NULL; |
fcd8b7c0 AG |
893 | |
894 | if (prev) | |
e622f2f4 | 895 | prev->s_send_wr.next = &send->s_rdma_wr.wr; |
fcd8b7c0 | 896 | |
e622f2f4 CH |
897 | for (j = 0; j < send->s_rdma_wr.wr.num_sge && |
898 | scat != &op->op_sg[op->op_count]; j++) { | |
fcd8b7c0 AG |
899 | len = ib_sg_dma_len(ic->i_cm_id->device, scat); |
900 | ||
e622f2f4 | 901 | if (send->s_rdma_wr.wr.opcode == IB_WR_RDMA_READ_WITH_INV) |
9ddc8737 | 902 | sg_nents++; |
fcd8b7c0 AG |
903 | else { |
904 | send->s_sge[j].addr = ib_sg_dma_address(ic->i_cm_id->device, scat); | |
905 | send->s_sge[j].length = len; | |
906 | send->s_sge[j].lkey = rds_iw_local_dma_lkey(ic); | |
907 | } | |
908 | ||
909 | sent += len; | |
910 | rdsdebug("ic %p sent %d remote_addr %llu\n", ic, sent, remote_addr); | |
911 | remote_addr += len; | |
912 | ||
913 | scat++; | |
914 | } | |
915 | ||
e622f2f4 CH |
916 | if (send->s_rdma_wr.wr.opcode == IB_WR_RDMA_READ_WITH_INV) { |
917 | send->s_rdma_wr.wr.num_sge = 1; | |
fcd8b7c0 AG |
918 | send->s_sge[0].addr = conn->c_xmit_rm->m_rs->rs_user_addr; |
919 | send->s_sge[0].length = conn->c_xmit_rm->m_rs->rs_user_bytes; | |
920 | send->s_sge[0].lkey = ic->i_sends[fr_pos].s_mr->lkey; | |
921 | } | |
922 | ||
923 | rdsdebug("send %p wr %p num_sge %u next %p\n", send, | |
e622f2f4 CH |
924 | &send->s_rdma_wr, |
925 | send->s_rdma_wr.wr.num_sge, | |
926 | send->s_rdma_wr.wr.next); | |
fcd8b7c0 AG |
927 | |
928 | prev = send; | |
929 | if (++send == &ic->i_sends[ic->i_send_ring.w_nr]) | |
930 | send = ic->i_sends; | |
931 | } | |
932 | ||
933 | /* if we finished the message then send completion owns it */ | |
f8b3aaf2 | 934 | if (scat == &op->op_sg[op->op_count]) |
e622f2f4 | 935 | first->s_rdma_wr.wr.send_flags = IB_SEND_SIGNALED; |
fcd8b7c0 AG |
936 | |
937 | if (i < work_alloc) { | |
938 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc - i); | |
939 | work_alloc = i; | |
940 | } | |
941 | ||
942 | /* On iWARP, local memory access by a remote system (ie, RDMA Read) is not | |
943 | * recommended. Putting the lkey on the wire is a security hole, as it can | |
944 | * allow for memory access to all of memory on the remote system. Some | |
945 | * adapters do not allow using the lkey for this at all. To bypass this use a | |
946 | * fastreg_mr (or possibly a dma_mr) | |
947 | */ | |
f8b3aaf2 | 948 | if (!op->op_write) { |
9ddc8737 SG |
949 | ret = rds_iw_build_send_reg(&ic->i_sends[fr_pos], |
950 | &op->op_sg[0], sg_nents); | |
951 | if (ret) { | |
952 | printk(KERN_WARNING "RDS/IW: failed to reg send mem\n"); | |
953 | goto out; | |
954 | } | |
fcd8b7c0 AG |
955 | work_alloc++; |
956 | } | |
957 | ||
e622f2f4 CH |
958 | failed_wr = &first->s_rdma_wr.wr; |
959 | ret = ib_post_send(ic->i_cm_id->qp, &first->s_rdma_wr.wr, &failed_wr); | |
fcd8b7c0 | 960 | rdsdebug("ic %p first %p (wr %p) ret %d wr %p\n", ic, |
e622f2f4 CH |
961 | first, &first->s_rdma_wr, ret, failed_wr); |
962 | BUG_ON(failed_wr != &first->s_rdma_wr.wr); | |
fcd8b7c0 AG |
963 | if (ret) { |
964 | printk(KERN_WARNING "RDS/IW: rdma ib_post_send to %pI4 " | |
965 | "returned %d\n", &conn->c_faddr, ret); | |
966 | rds_iw_ring_unalloc(&ic->i_send_ring, work_alloc); | |
967 | goto out; | |
968 | } | |
969 | ||
970 | out: | |
971 | return ret; | |
972 | } | |
973 | ||
974 | void rds_iw_xmit_complete(struct rds_connection *conn) | |
975 | { | |
976 | struct rds_iw_connection *ic = conn->c_transport_data; | |
977 | ||
978 | /* We may have a pending ACK or window update we were unable | |
979 | * to send previously (due to flow control). Try again. */ | |
980 | rds_iw_attempt_ack(ic); | |
981 | } |