1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
2 /*
3 * Copyright(c) 2016 - 2018 Intel Corporation.
4 */
5
6 #include <linux/slab.h>
7 #include <linux/vmalloc.h>
8 #include "cq.h"
9 #include "vt.h"
10 #include "trace.h"
11
12 static struct workqueue_struct *comp_vector_wq;
13
14 /**
15 * rvt_cq_enter - add a new entry to the completion queue
16 * @cq: completion queue
17 * @entry: work completion entry to add
18 * @solicited: true if @entry is solicited
19 *
20 * This may be called with qp->s_lock held.
21 *
22 * Return: return true on success, else return
23 * false if cq is full.
24 */
rvt_cq_enter(struct rvt_cq * cq,struct ib_wc * entry,bool solicited)25 bool rvt_cq_enter(struct rvt_cq *cq, struct ib_wc *entry, bool solicited)
26 {
27 struct ib_uverbs_wc *uqueue = NULL;
28 struct ib_wc *kqueue = NULL;
29 struct rvt_cq_wc *u_wc = NULL;
30 struct rvt_k_cq_wc *k_wc = NULL;
31 unsigned long flags;
32 u32 head;
33 u32 next;
34 u32 tail;
35
36 spin_lock_irqsave(&cq->lock, flags);
37
38 if (cq->ip) {
39 u_wc = cq->queue;
40 uqueue = &u_wc->uqueue[0];
41 head = RDMA_READ_UAPI_ATOMIC(u_wc->head);
42 tail = RDMA_READ_UAPI_ATOMIC(u_wc->tail);
43 } else {
44 k_wc = cq->kqueue;
45 kqueue = &k_wc->kqueue[0];
46 head = k_wc->head;
47 tail = k_wc->tail;
48 }
49
50 /*
51 * Note that the head pointer might be writable by
52 * user processes.Take care to verify it is a sane value.
53 */
54 if (head >= (unsigned)cq->ibcq.cqe) {
55 head = cq->ibcq.cqe;
56 next = 0;
57 } else {
58 next = head + 1;
59 }
60
61 if (unlikely(next == tail || cq->cq_full)) {
62 struct rvt_dev_info *rdi = cq->rdi;
63
64 if (!cq->cq_full)
65 rvt_pr_err_ratelimited(rdi, "CQ is full!\n");
66 cq->cq_full = true;
67 spin_unlock_irqrestore(&cq->lock, flags);
68 if (cq->ibcq.event_handler) {
69 struct ib_event ev;
70
71 ev.device = cq->ibcq.device;
72 ev.element.cq = &cq->ibcq;
73 ev.event = IB_EVENT_CQ_ERR;
74 cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
75 }
76 return false;
77 }
78 trace_rvt_cq_enter(cq, entry, head);
79 if (uqueue) {
80 uqueue[head].wr_id = entry->wr_id;
81 uqueue[head].status = entry->status;
82 uqueue[head].opcode = entry->opcode;
83 uqueue[head].vendor_err = entry->vendor_err;
84 uqueue[head].byte_len = entry->byte_len;
85 uqueue[head].ex.imm_data = entry->ex.imm_data;
86 uqueue[head].qp_num = entry->qp->qp_num;
87 uqueue[head].src_qp = entry->src_qp;
88 uqueue[head].wc_flags = entry->wc_flags;
89 uqueue[head].pkey_index = entry->pkey_index;
90 uqueue[head].slid = ib_lid_cpu16(entry->slid);
91 uqueue[head].sl = entry->sl;
92 uqueue[head].dlid_path_bits = entry->dlid_path_bits;
93 uqueue[head].port_num = entry->port_num;
94 /* Make sure entry is written before the head index. */
95 RDMA_WRITE_UAPI_ATOMIC(u_wc->head, next);
96 } else {
97 kqueue[head] = *entry;
98 k_wc->head = next;
99 }
100
101 if (cq->notify == IB_CQ_NEXT_COMP ||
102 (cq->notify == IB_CQ_SOLICITED &&
103 (solicited || entry->status != IB_WC_SUCCESS))) {
104 /*
105 * This will cause send_complete() to be called in
106 * another thread.
107 */
108 cq->notify = RVT_CQ_NONE;
109 cq->triggered++;
110 queue_work_on(cq->comp_vector_cpu, comp_vector_wq,
111 &cq->comptask);
112 }
113
114 spin_unlock_irqrestore(&cq->lock, flags);
115 return true;
116 }
117 EXPORT_SYMBOL(rvt_cq_enter);
118
send_complete(struct work_struct * work)119 static void send_complete(struct work_struct *work)
120 {
121 struct rvt_cq *cq = container_of(work, struct rvt_cq, comptask);
122
123 /*
124 * The completion handler will most likely rearm the notification
125 * and poll for all pending entries. If a new completion entry
126 * is added while we are in this routine, queue_work()
127 * won't call us again until we return so we check triggered to
128 * see if we need to call the handler again.
129 */
130 for (;;) {
131 u8 triggered = cq->triggered;
132
133 /*
134 * IPoIB connected mode assumes the callback is from a
135 * soft IRQ. We simulate this by blocking "bottom halves".
136 * See the implementation for ipoib_cm_handle_tx_wc(),
137 * netif_tx_lock_bh() and netif_tx_lock().
138 */
139 local_bh_disable();
140 cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
141 local_bh_enable();
142
143 if (cq->triggered == triggered)
144 return;
145 }
146 }
147
148 /**
149 * rvt_create_cq - create a completion queue
150 * @ibcq: Allocated CQ
151 * @attr: creation attributes
152 * @udata: user data for libibverbs.so
153 *
154 * Called by ib_create_cq() in the generic verbs code.
155 *
156 * Return: 0 on success
157 */
rvt_create_cq(struct ib_cq * ibcq,const struct ib_cq_init_attr * attr,struct ib_udata * udata)158 int rvt_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
159 struct ib_udata *udata)
160 {
161 struct ib_device *ibdev = ibcq->device;
162 struct rvt_dev_info *rdi = ib_to_rvt(ibdev);
163 struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
164 struct rvt_cq_wc *u_wc = NULL;
165 struct rvt_k_cq_wc *k_wc = NULL;
166 u32 sz;
167 unsigned int entries = attr->cqe;
168 int comp_vector = attr->comp_vector;
169 int err;
170
171 if (attr->flags)
172 return -EOPNOTSUPP;
173
174 if (entries < 1 || entries > rdi->dparms.props.max_cqe)
175 return -EINVAL;
176
177 if (comp_vector < 0)
178 comp_vector = 0;
179
180 comp_vector = comp_vector % rdi->ibdev.num_comp_vectors;
181
182 /*
183 * Allocate the completion queue entries and head/tail pointers.
184 * This is allocated separately so that it can be resized and
185 * also mapped into user space.
186 * We need to use vmalloc() in order to support mmap and large
187 * numbers of entries.
188 */
189 if (udata && udata->outlen >= sizeof(__u64)) {
190 sz = sizeof(struct ib_uverbs_wc) * (entries + 1);
191 sz += sizeof(*u_wc);
192 u_wc = vmalloc_user(sz);
193 if (!u_wc)
194 return -ENOMEM;
195 } else {
196 sz = sizeof(struct ib_wc) * (entries + 1);
197 sz += sizeof(*k_wc);
198 k_wc = vzalloc_node(sz, rdi->dparms.node);
199 if (!k_wc)
200 return -ENOMEM;
201 }
202
203 /*
204 * Return the address of the WC as the offset to mmap.
205 * See rvt_mmap() for details.
206 */
207 if (udata && udata->outlen >= sizeof(__u64)) {
208 cq->ip = rvt_create_mmap_info(rdi, sz, udata, u_wc);
209 if (IS_ERR(cq->ip)) {
210 err = PTR_ERR(cq->ip);
211 goto bail_wc;
212 }
213
214 err = ib_copy_to_udata(udata, &cq->ip->offset,
215 sizeof(cq->ip->offset));
216 if (err)
217 goto bail_ip;
218 }
219
220 spin_lock_irq(&rdi->n_cqs_lock);
221 if (rdi->n_cqs_allocated == rdi->dparms.props.max_cq) {
222 spin_unlock_irq(&rdi->n_cqs_lock);
223 err = -ENOMEM;
224 goto bail_ip;
225 }
226
227 rdi->n_cqs_allocated++;
228 spin_unlock_irq(&rdi->n_cqs_lock);
229
230 if (cq->ip) {
231 spin_lock_irq(&rdi->pending_lock);
232 list_add(&cq->ip->pending_mmaps, &rdi->pending_mmaps);
233 spin_unlock_irq(&rdi->pending_lock);
234 }
235
236 /*
237 * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
238 * The number of entries should be >= the number requested or return
239 * an error.
240 */
241 cq->rdi = rdi;
242 if (rdi->driver_f.comp_vect_cpu_lookup)
243 cq->comp_vector_cpu =
244 rdi->driver_f.comp_vect_cpu_lookup(rdi, comp_vector);
245 else
246 cq->comp_vector_cpu =
247 cpumask_first(cpumask_of_node(rdi->dparms.node));
248
249 cq->ibcq.cqe = entries;
250 cq->notify = RVT_CQ_NONE;
251 spin_lock_init(&cq->lock);
252 INIT_WORK(&cq->comptask, send_complete);
253 if (u_wc)
254 cq->queue = u_wc;
255 else
256 cq->kqueue = k_wc;
257
258 trace_rvt_create_cq(cq, attr);
259 return 0;
260
261 bail_ip:
262 kfree(cq->ip);
263 bail_wc:
264 vfree(u_wc);
265 vfree(k_wc);
266 return err;
267 }
268
269 /**
270 * rvt_destroy_cq - destroy a completion queue
271 * @ibcq: the completion queue to destroy.
272 * @udata: user data or NULL for kernel object
273 *
274 * Called by ib_destroy_cq() in the generic verbs code.
275 */
rvt_destroy_cq(struct ib_cq * ibcq,struct ib_udata * udata)276 int rvt_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata)
277 {
278 struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
279 struct rvt_dev_info *rdi = cq->rdi;
280
281 flush_work(&cq->comptask);
282 spin_lock_irq(&rdi->n_cqs_lock);
283 rdi->n_cqs_allocated--;
284 spin_unlock_irq(&rdi->n_cqs_lock);
285 if (cq->ip)
286 kref_put(&cq->ip->ref, rvt_release_mmap_info);
287 else
288 vfree(cq->kqueue);
289 return 0;
290 }
291
292 /**
293 * rvt_req_notify_cq - change the notification type for a completion queue
294 * @ibcq: the completion queue
295 * @notify_flags: the type of notification to request
296 *
297 * This may be called from interrupt context. Also called by
298 * ib_req_notify_cq() in the generic verbs code.
299 *
300 * Return: 0 for success.
301 */
rvt_req_notify_cq(struct ib_cq * ibcq,enum ib_cq_notify_flags notify_flags)302 int rvt_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
303 {
304 struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
305 unsigned long flags;
306 int ret = 0;
307
308 spin_lock_irqsave(&cq->lock, flags);
309 /*
310 * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow
311 * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2).
312 */
313 if (cq->notify != IB_CQ_NEXT_COMP)
314 cq->notify = notify_flags & IB_CQ_SOLICITED_MASK;
315
316 if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
317 if (cq->queue) {
318 if (RDMA_READ_UAPI_ATOMIC(cq->queue->head) !=
319 RDMA_READ_UAPI_ATOMIC(cq->queue->tail))
320 ret = 1;
321 } else {
322 if (cq->kqueue->head != cq->kqueue->tail)
323 ret = 1;
324 }
325 }
326
327 spin_unlock_irqrestore(&cq->lock, flags);
328
329 return ret;
330 }
331
332 /*
333 * rvt_resize_cq - change the size of the CQ
334 * @ibcq: the completion queue
335 *
336 * Return: 0 for success.
337 */
rvt_resize_cq(struct ib_cq * ibcq,int cqe,struct ib_udata * udata)338 int rvt_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
339 {
340 struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
341 u32 head, tail, n;
342 int ret;
343 u32 sz;
344 struct rvt_dev_info *rdi = cq->rdi;
345 struct rvt_cq_wc *u_wc = NULL;
346 struct rvt_cq_wc *old_u_wc = NULL;
347 struct rvt_k_cq_wc *k_wc = NULL;
348 struct rvt_k_cq_wc *old_k_wc = NULL;
349
350 if (cqe < 1 || cqe > rdi->dparms.props.max_cqe)
351 return -EINVAL;
352
353 /*
354 * Need to use vmalloc() if we want to support large #s of entries.
355 */
356 if (udata && udata->outlen >= sizeof(__u64)) {
357 sz = sizeof(struct ib_uverbs_wc) * (cqe + 1);
358 sz += sizeof(*u_wc);
359 u_wc = vmalloc_user(sz);
360 if (!u_wc)
361 return -ENOMEM;
362 } else {
363 sz = sizeof(struct ib_wc) * (cqe + 1);
364 sz += sizeof(*k_wc);
365 k_wc = vzalloc_node(sz, rdi->dparms.node);
366 if (!k_wc)
367 return -ENOMEM;
368 }
369 /* Check that we can write the offset to mmap. */
370 if (udata && udata->outlen >= sizeof(__u64)) {
371 __u64 offset = 0;
372
373 ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
374 if (ret)
375 goto bail_free;
376 }
377
378 spin_lock_irq(&cq->lock);
379 /*
380 * Make sure head and tail are sane since they
381 * might be user writable.
382 */
383 if (u_wc) {
384 old_u_wc = cq->queue;
385 head = RDMA_READ_UAPI_ATOMIC(old_u_wc->head);
386 tail = RDMA_READ_UAPI_ATOMIC(old_u_wc->tail);
387 } else {
388 old_k_wc = cq->kqueue;
389 head = old_k_wc->head;
390 tail = old_k_wc->tail;
391 }
392
393 if (head > (u32)cq->ibcq.cqe)
394 head = (u32)cq->ibcq.cqe;
395 if (tail > (u32)cq->ibcq.cqe)
396 tail = (u32)cq->ibcq.cqe;
397 if (head < tail)
398 n = cq->ibcq.cqe + 1 + head - tail;
399 else
400 n = head - tail;
401 if (unlikely((u32)cqe < n)) {
402 ret = -EINVAL;
403 goto bail_unlock;
404 }
405 for (n = 0; tail != head; n++) {
406 if (u_wc)
407 u_wc->uqueue[n] = old_u_wc->uqueue[tail];
408 else
409 k_wc->kqueue[n] = old_k_wc->kqueue[tail];
410 if (tail == (u32)cq->ibcq.cqe)
411 tail = 0;
412 else
413 tail++;
414 }
415 cq->ibcq.cqe = cqe;
416 if (u_wc) {
417 RDMA_WRITE_UAPI_ATOMIC(u_wc->head, n);
418 RDMA_WRITE_UAPI_ATOMIC(u_wc->tail, 0);
419 cq->queue = u_wc;
420 } else {
421 k_wc->head = n;
422 k_wc->tail = 0;
423 cq->kqueue = k_wc;
424 }
425 spin_unlock_irq(&cq->lock);
426
427 if (u_wc)
428 vfree(old_u_wc);
429 else
430 vfree(old_k_wc);
431
432 if (cq->ip) {
433 struct rvt_mmap_info *ip = cq->ip;
434
435 rvt_update_mmap_info(rdi, ip, sz, u_wc);
436
437 /*
438 * Return the offset to mmap.
439 * See rvt_mmap() for details.
440 */
441 if (udata && udata->outlen >= sizeof(__u64)) {
442 ret = ib_copy_to_udata(udata, &ip->offset,
443 sizeof(ip->offset));
444 if (ret)
445 return ret;
446 }
447
448 spin_lock_irq(&rdi->pending_lock);
449 if (list_empty(&ip->pending_mmaps))
450 list_add(&ip->pending_mmaps, &rdi->pending_mmaps);
451 spin_unlock_irq(&rdi->pending_lock);
452 }
453
454 return 0;
455
456 bail_unlock:
457 spin_unlock_irq(&cq->lock);
458 bail_free:
459 vfree(u_wc);
460 vfree(k_wc);
461
462 return ret;
463 }
464
465 /**
466 * rvt_poll_cq - poll for work completion entries
467 * @ibcq: the completion queue to poll
468 * @num_entries: the maximum number of entries to return
469 * @entry: pointer to array where work completions are placed
470 *
471 * This may be called from interrupt context. Also called by ib_poll_cq()
472 * in the generic verbs code.
473 *
474 * Return: the number of completion entries polled.
475 */
rvt_poll_cq(struct ib_cq * ibcq,int num_entries,struct ib_wc * entry)476 int rvt_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
477 {
478 struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
479 struct rvt_k_cq_wc *wc;
480 unsigned long flags;
481 int npolled;
482 u32 tail;
483
484 /* The kernel can only poll a kernel completion queue */
485 if (cq->ip)
486 return -EINVAL;
487
488 spin_lock_irqsave(&cq->lock, flags);
489
490 wc = cq->kqueue;
491 tail = wc->tail;
492 if (tail > (u32)cq->ibcq.cqe)
493 tail = (u32)cq->ibcq.cqe;
494 for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
495 if (tail == wc->head)
496 break;
497 /* The kernel doesn't need a RMB since it has the lock. */
498 trace_rvt_cq_poll(cq, &wc->kqueue[tail], npolled);
499 *entry = wc->kqueue[tail];
500 if (tail >= cq->ibcq.cqe)
501 tail = 0;
502 else
503 tail++;
504 }
505 wc->tail = tail;
506
507 spin_unlock_irqrestore(&cq->lock, flags);
508
509 return npolled;
510 }
511
512 /**
513 * rvt_driver_cq_init - Init cq resources on behalf of driver
514 *
515 * Return: 0 on success
516 */
rvt_driver_cq_init(void)517 int rvt_driver_cq_init(void)
518 {
519 comp_vector_wq = alloc_workqueue("%s", WQ_HIGHPRI | WQ_CPU_INTENSIVE,
520 0, "rdmavt_cq");
521 if (!comp_vector_wq)
522 return -ENOMEM;
523
524 return 0;
525 }
526
527 /**
528 * rvt_cq_exit - tear down cq reources
529 */
rvt_cq_exit(void)530 void rvt_cq_exit(void)
531 {
532 destroy_workqueue(comp_vector_wq);
533 comp_vector_wq = NULL;
534 }
535