Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2015 HGST, a Western Digital Company.
4 */
5#include <linux/err.h>
6#include <linux/slab.h>
7#include <rdma/ib_verbs.h>
8
9#include "core_priv.h"
10
11#include <trace/events/rdma_core.h>
12/* Max size for shared CQ, may require tuning */
13#define IB_MAX_SHARED_CQ_SZ 4096U
14
15/* # of WCs to poll for with a single call to ib_poll_cq */
16#define IB_POLL_BATCH 16
17#define IB_POLL_BATCH_DIRECT 8
18
19/* # of WCs to iterate over before yielding */
20#define IB_POLL_BUDGET_IRQ 256
21#define IB_POLL_BUDGET_WORKQUEUE 65536
22
23#define IB_POLL_FLAGS \
24 (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
25
26static const struct dim_cq_moder
27rdma_dim_prof[RDMA_DIM_PARAMS_NUM_PROFILES] = {
28 {1, 0, 1, 0},
29 {1, 0, 4, 0},
30 {2, 0, 4, 0},
31 {2, 0, 8, 0},
32 {4, 0, 8, 0},
33 {16, 0, 8, 0},
34 {16, 0, 16, 0},
35 {32, 0, 16, 0},
36 {32, 0, 32, 0},
37};
38
39static void ib_cq_rdma_dim_work(struct work_struct *w)
40{
41 struct dim *dim = container_of(w, struct dim, work);
42 struct ib_cq *cq = dim->priv;
43
44 u16 usec = rdma_dim_prof[dim->profile_ix].usec;
45 u16 comps = rdma_dim_prof[dim->profile_ix].comps;
46
47 dim->state = DIM_START_MEASURE;
48
49 trace_cq_modify(cq, comps, usec);
50 cq->device->ops.modify_cq(cq, comps, usec);
51}
52
53static void rdma_dim_init(struct ib_cq *cq)
54{
55 struct dim *dim;
56
57 if (!cq->device->ops.modify_cq || !cq->device->use_cq_dim ||
58 cq->poll_ctx == IB_POLL_DIRECT)
59 return;
60
61 dim = kzalloc(sizeof(struct dim), GFP_KERNEL);
62 if (!dim)
63 return;
64
65 dim->state = DIM_START_MEASURE;
66 dim->tune_state = DIM_GOING_RIGHT;
67 dim->profile_ix = RDMA_DIM_START_PROFILE;
68 dim->priv = cq;
69 cq->dim = dim;
70
71 INIT_WORK(&dim->work, ib_cq_rdma_dim_work);
72}
73
74static void rdma_dim_destroy(struct ib_cq *cq)
75{
76 if (!cq->dim)
77 return;
78
79 cancel_work_sync(&cq->dim->work);
80 kfree(cq->dim);
81}
82
83static int __poll_cq(struct ib_cq *cq, int num_entries, struct ib_wc *wc)
84{
85 int rc;
86
87 rc = ib_poll_cq(cq, num_entries, wc);
88 trace_cq_poll(cq, num_entries, rc);
89 return rc;
90}
91
92static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *wcs,
93 int batch)
94{
95 int i, n, completed = 0;
96
97 trace_cq_process(cq);
98
99 /*
100 * budget might be (-1) if the caller does not
101 * want to bound this call, thus we need unsigned
102 * minimum here.
103 */
104 while ((n = __poll_cq(cq, min_t(u32, batch,
105 budget - completed), wcs)) > 0) {
106 for (i = 0; i < n; i++) {
107 struct ib_wc *wc = &wcs[i];
108
109 if (wc->wr_cqe)
110 wc->wr_cqe->done(cq, wc);
111 else
112 WARN_ON_ONCE(wc->status == IB_WC_SUCCESS);
113 }
114
115 completed += n;
116
117 if (n != batch || (budget != -1 && completed >= budget))
118 break;
119 }
120
121 return completed;
122}
123
124/**
125 * ib_process_cq_direct - process a CQ in caller context
126 * @cq: CQ to process
127 * @budget: number of CQEs to poll for
128 *
129 * This function is used to process all outstanding CQ entries.
130 * It does not offload CQ processing to a different context and does
131 * not ask for completion interrupts from the HCA.
132 * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
133 * concurrent processing.
134 *
135 * Note: do not pass -1 as %budget unless it is guaranteed that the number
136 * of completions that will be processed is small.
137 */
138int ib_process_cq_direct(struct ib_cq *cq, int budget)
139{
140 struct ib_wc wcs[IB_POLL_BATCH_DIRECT];
141
142 return __ib_process_cq(cq, budget, wcs, IB_POLL_BATCH_DIRECT);
143}
144EXPORT_SYMBOL(ib_process_cq_direct);
145
146static void ib_cq_completion_direct(struct ib_cq *cq, void *private)
147{
148 WARN_ONCE(1, "got unsolicited completion for CQ 0x%p\n", cq);
149}
150
151static int ib_poll_handler(struct irq_poll *iop, int budget)
152{
153 struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
154 struct dim *dim = cq->dim;
155 int completed;
156
157 completed = __ib_process_cq(cq, budget, cq->wc, IB_POLL_BATCH);
158 if (completed < budget) {
159 irq_poll_complete(&cq->iop);
160 if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) {
161 trace_cq_reschedule(cq);
162 irq_poll_sched(&cq->iop);
163 }
164 }
165
166 if (dim)
167 rdma_dim(dim, completed);
168
169 return completed;
170}
171
172static void ib_cq_completion_softirq(struct ib_cq *cq, void *private)
173{
174 trace_cq_schedule(cq);
175 irq_poll_sched(&cq->iop);
176}
177
178static void ib_cq_poll_work(struct work_struct *work)
179{
180 struct ib_cq *cq = container_of(work, struct ib_cq, work);
181 int completed;
182
183 completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, cq->wc,
184 IB_POLL_BATCH);
185 if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
186 ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
187 queue_work(cq->comp_wq, &cq->work);
188 else if (cq->dim)
189 rdma_dim(cq->dim, completed);
190}
191
192static void ib_cq_completion_workqueue(struct ib_cq *cq, void *private)
193{
194 trace_cq_schedule(cq);
195 queue_work(cq->comp_wq, &cq->work);
196}
197
198/**
199 * __ib_alloc_cq - allocate a completion queue
200 * @dev: device to allocate the CQ for
201 * @private: driver private data, accessible from cq->cq_context
202 * @nr_cqe: number of CQEs to allocate
203 * @comp_vector: HCA completion vectors for this CQ
204 * @poll_ctx: context to poll the CQ from.
205 * @caller: module owner name.
206 *
207 * This is the proper interface to allocate a CQ for in-kernel users. A
208 * CQ allocated with this interface will automatically be polled from the
209 * specified context. The ULP must use wr->wr_cqe instead of wr->wr_id
210 * to use this CQ abstraction.
211 */
212struct ib_cq *__ib_alloc_cq(struct ib_device *dev, void *private, int nr_cqe,
213 int comp_vector, enum ib_poll_context poll_ctx,
214 const char *caller)
215{
216 struct ib_cq_init_attr cq_attr = {
217 .cqe = nr_cqe,
218 .comp_vector = comp_vector,
219 };
220 struct ib_cq *cq;
221 int ret = -ENOMEM;
222
223 cq = rdma_zalloc_drv_obj(dev, ib_cq);
224 if (!cq)
225 return ERR_PTR(ret);
226
227 cq->device = dev;
228 cq->cq_context = private;
229 cq->poll_ctx = poll_ctx;
230 atomic_set(&cq->usecnt, 0);
231 cq->comp_vector = comp_vector;
232
233 cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL);
234 if (!cq->wc)
235 goto out_free_cq;
236
237 rdma_restrack_new(&cq->res, RDMA_RESTRACK_CQ);
238 rdma_restrack_set_name(&cq->res, caller);
239
240 ret = dev->ops.create_cq(cq, &cq_attr, NULL);
241 if (ret)
242 goto out_free_wc;
243
244 rdma_dim_init(cq);
245
246 switch (cq->poll_ctx) {
247 case IB_POLL_DIRECT:
248 cq->comp_handler = ib_cq_completion_direct;
249 break;
250 case IB_POLL_SOFTIRQ:
251 cq->comp_handler = ib_cq_completion_softirq;
252
253 irq_poll_init(&cq->iop, IB_POLL_BUDGET_IRQ, ib_poll_handler);
254 ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
255 break;
256 case IB_POLL_WORKQUEUE:
257 case IB_POLL_UNBOUND_WORKQUEUE:
258 cq->comp_handler = ib_cq_completion_workqueue;
259 INIT_WORK(&cq->work, ib_cq_poll_work);
260 ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
261 cq->comp_wq = (cq->poll_ctx == IB_POLL_WORKQUEUE) ?
262 ib_comp_wq : ib_comp_unbound_wq;
263 break;
264 default:
265 ret = -EINVAL;
266 goto out_destroy_cq;
267 }
268
269 rdma_restrack_add(&cq->res);
270 trace_cq_alloc(cq, nr_cqe, comp_vector, poll_ctx);
271 return cq;
272
273out_destroy_cq:
274 rdma_dim_destroy(cq);
275 cq->device->ops.destroy_cq(cq, NULL);
276out_free_wc:
277 rdma_restrack_put(&cq->res);
278 kfree(cq->wc);
279out_free_cq:
280 kfree(cq);
281 trace_cq_alloc_error(nr_cqe, comp_vector, poll_ctx, ret);
282 return ERR_PTR(ret);
283}
284EXPORT_SYMBOL(__ib_alloc_cq);
285
286/**
287 * __ib_alloc_cq_any - allocate a completion queue
288 * @dev: device to allocate the CQ for
289 * @private: driver private data, accessible from cq->cq_context
290 * @nr_cqe: number of CQEs to allocate
291 * @poll_ctx: context to poll the CQ from
292 * @caller: module owner name
293 *
294 * Attempt to spread ULP Completion Queues over each device's interrupt
295 * vectors. A simple best-effort mechanism is used.
296 */
297struct ib_cq *__ib_alloc_cq_any(struct ib_device *dev, void *private,
298 int nr_cqe, enum ib_poll_context poll_ctx,
299 const char *caller)
300{
301 static atomic_t counter;
302 int comp_vector = 0;
303
304 if (dev->num_comp_vectors > 1)
305 comp_vector =
306 atomic_inc_return(&counter) %
307 min_t(int, dev->num_comp_vectors, num_online_cpus());
308
309 return __ib_alloc_cq(dev, private, nr_cqe, comp_vector, poll_ctx,
310 caller);
311}
312EXPORT_SYMBOL(__ib_alloc_cq_any);
313
314/**
315 * ib_free_cq - free a completion queue
316 * @cq: completion queue to free.
317 */
318void ib_free_cq(struct ib_cq *cq)
319{
320 int ret;
321
322 if (WARN_ON_ONCE(atomic_read(&cq->usecnt)))
323 return;
324 if (WARN_ON_ONCE(cq->cqe_used))
325 return;
326
327 switch (cq->poll_ctx) {
328 case IB_POLL_DIRECT:
329 break;
330 case IB_POLL_SOFTIRQ:
331 irq_poll_disable(&cq->iop);
332 break;
333 case IB_POLL_WORKQUEUE:
334 case IB_POLL_UNBOUND_WORKQUEUE:
335 cancel_work_sync(&cq->work);
336 break;
337 default:
338 WARN_ON_ONCE(1);
339 }
340
341 rdma_dim_destroy(cq);
342 trace_cq_free(cq);
343 ret = cq->device->ops.destroy_cq(cq, NULL);
344 WARN_ONCE(ret, "Destroy of kernel CQ shouldn't fail");
345 rdma_restrack_del(&cq->res);
346 kfree(cq->wc);
347 kfree(cq);
348}
349EXPORT_SYMBOL(ib_free_cq);
350
351void ib_cq_pool_cleanup(struct ib_device *dev)
352{
353 struct ib_cq *cq, *n;
354 unsigned int i;
355
356 for (i = 0; i < ARRAY_SIZE(dev->cq_pools); i++) {
357 list_for_each_entry_safe(cq, n, &dev->cq_pools[i],
358 pool_entry) {
359 WARN_ON(cq->cqe_used);
360 list_del(&cq->pool_entry);
361 cq->shared = false;
362 ib_free_cq(cq);
363 }
364 }
365}
366
367static int ib_alloc_cqs(struct ib_device *dev, unsigned int nr_cqes,
368 enum ib_poll_context poll_ctx)
369{
370 LIST_HEAD(tmp_list);
371 unsigned int nr_cqs, i;
372 struct ib_cq *cq, *n;
373 int ret;
374
375 if (poll_ctx > IB_POLL_LAST_POOL_TYPE) {
376 WARN_ON_ONCE(poll_ctx > IB_POLL_LAST_POOL_TYPE);
377 return -EINVAL;
378 }
379
380 /*
381 * Allocate at least as many CQEs as requested, and otherwise
382 * a reasonable batch size so that we can share CQs between
383 * multiple users instead of allocating a larger number of CQs.
384 */
385 nr_cqes = min_t(unsigned int, dev->attrs.max_cqe,
386 max(nr_cqes, IB_MAX_SHARED_CQ_SZ));
387 nr_cqs = min_t(unsigned int, dev->num_comp_vectors, num_online_cpus());
388 for (i = 0; i < nr_cqs; i++) {
389 cq = ib_alloc_cq(dev, NULL, nr_cqes, i, poll_ctx);
390 if (IS_ERR(cq)) {
391 ret = PTR_ERR(cq);
392 goto out_free_cqs;
393 }
394 cq->shared = true;
395 list_add_tail(&cq->pool_entry, &tmp_list);
396 }
397
398 spin_lock_irq(&dev->cq_pools_lock);
399 list_splice(&tmp_list, &dev->cq_pools[poll_ctx]);
400 spin_unlock_irq(&dev->cq_pools_lock);
401
402 return 0;
403
404out_free_cqs:
405 list_for_each_entry_safe(cq, n, &tmp_list, pool_entry) {
406 cq->shared = false;
407 ib_free_cq(cq);
408 }
409 return ret;
410}
411
412/**
413 * ib_cq_pool_get() - Find the least used completion queue that matches
414 * a given cpu hint (or least used for wild card affinity) and fits
415 * nr_cqe.
416 * @dev: rdma device
417 * @nr_cqe: number of needed cqe entries
418 * @comp_vector_hint: completion vector hint (-1) for the driver to assign
419 * a comp vector based on internal counter
420 * @poll_ctx: cq polling context
421 *
422 * Finds a cq that satisfies @comp_vector_hint and @nr_cqe requirements and
423 * claim entries in it for us. In case there is no available cq, allocate
424 * a new cq with the requirements and add it to the device pool.
425 * IB_POLL_DIRECT cannot be used for shared cqs so it is not a valid value
426 * for @poll_ctx.
427 */
428struct ib_cq *ib_cq_pool_get(struct ib_device *dev, unsigned int nr_cqe,
429 int comp_vector_hint,
430 enum ib_poll_context poll_ctx)
431{
432 static unsigned int default_comp_vector;
433 unsigned int vector, num_comp_vectors;
434 struct ib_cq *cq, *found = NULL;
435 int ret;
436
437 if (poll_ctx > IB_POLL_LAST_POOL_TYPE) {
438 WARN_ON_ONCE(poll_ctx > IB_POLL_LAST_POOL_TYPE);
439 return ERR_PTR(-EINVAL);
440 }
441
442 num_comp_vectors =
443 min_t(unsigned int, dev->num_comp_vectors, num_online_cpus());
444 /* Project the affinty to the device completion vector range */
445 if (comp_vector_hint < 0) {
446 comp_vector_hint =
447 (READ_ONCE(default_comp_vector) + 1) % num_comp_vectors;
448 WRITE_ONCE(default_comp_vector, comp_vector_hint);
449 }
450 vector = comp_vector_hint % num_comp_vectors;
451
452 /*
453 * Find the least used CQ with correct affinity and
454 * enough free CQ entries
455 */
456 while (!found) {
457 spin_lock_irq(&dev->cq_pools_lock);
458 list_for_each_entry(cq, &dev->cq_pools[poll_ctx],
459 pool_entry) {
460 /*
461 * Check to see if we have found a CQ with the
462 * correct completion vector
463 */
464 if (vector != cq->comp_vector)
465 continue;
466 if (cq->cqe_used + nr_cqe > cq->cqe)
467 continue;
468 found = cq;
469 break;
470 }
471
472 if (found) {
473 found->cqe_used += nr_cqe;
474 spin_unlock_irq(&dev->cq_pools_lock);
475
476 return found;
477 }
478 spin_unlock_irq(&dev->cq_pools_lock);
479
480 /*
481 * Didn't find a match or ran out of CQs in the device
482 * pool, allocate a new array of CQs.
483 */
484 ret = ib_alloc_cqs(dev, nr_cqe, poll_ctx);
485 if (ret)
486 return ERR_PTR(ret);
487 }
488
489 return found;
490}
491EXPORT_SYMBOL(ib_cq_pool_get);
492
493/**
494 * ib_cq_pool_put - Return a CQ taken from a shared pool.
495 * @cq: The CQ to return.
496 * @nr_cqe: The max number of cqes that the user had requested.
497 */
498void ib_cq_pool_put(struct ib_cq *cq, unsigned int nr_cqe)
499{
500 if (WARN_ON_ONCE(nr_cqe > cq->cqe_used))
501 return;
502
503 spin_lock_irq(&cq->device->cq_pools_lock);
504 cq->cqe_used -= nr_cqe;
505 spin_unlock_irq(&cq->device->cq_pools_lock);
506}
507EXPORT_SYMBOL(ib_cq_pool_put);
1/*
2 * Copyright (c) 2015 HGST, a Western Digital Company.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 */
13#include <linux/module.h>
14#include <linux/err.h>
15#include <linux/slab.h>
16#include <rdma/ib_verbs.h>
17
18/* # of WCs to poll for with a single call to ib_poll_cq */
19#define IB_POLL_BATCH 16
20
21/* # of WCs to iterate over before yielding */
22#define IB_POLL_BUDGET_IRQ 256
23#define IB_POLL_BUDGET_WORKQUEUE 65536
24
25#define IB_POLL_FLAGS \
26 (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
27
28static int __ib_process_cq(struct ib_cq *cq, int budget)
29{
30 int i, n, completed = 0;
31
32 while ((n = ib_poll_cq(cq, IB_POLL_BATCH, cq->wc)) > 0) {
33 for (i = 0; i < n; i++) {
34 struct ib_wc *wc = &cq->wc[i];
35
36 if (wc->wr_cqe)
37 wc->wr_cqe->done(cq, wc);
38 else
39 WARN_ON_ONCE(wc->status == IB_WC_SUCCESS);
40 }
41
42 completed += n;
43
44 if (n != IB_POLL_BATCH ||
45 (budget != -1 && completed >= budget))
46 break;
47 }
48
49 return completed;
50}
51
52/**
53 * ib_process_direct_cq - process a CQ in caller context
54 * @cq: CQ to process
55 * @budget: number of CQEs to poll for
56 *
57 * This function is used to process all outstanding CQ entries on a
58 * %IB_POLL_DIRECT CQ. It does not offload CQ processing to a different
59 * context and does not ask for completion interrupts from the HCA.
60 *
61 * Note: for compatibility reasons -1 can be passed in %budget for unlimited
62 * polling. Do not use this feature in new code, it will be removed soon.
63 */
64int ib_process_cq_direct(struct ib_cq *cq, int budget)
65{
66 WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
67
68 return __ib_process_cq(cq, budget);
69}
70EXPORT_SYMBOL(ib_process_cq_direct);
71
72static void ib_cq_completion_direct(struct ib_cq *cq, void *private)
73{
74 WARN_ONCE(1, "got unsolicited completion for CQ 0x%p\n", cq);
75}
76
77static int ib_poll_handler(struct irq_poll *iop, int budget)
78{
79 struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
80 int completed;
81
82 completed = __ib_process_cq(cq, budget);
83 if (completed < budget) {
84 irq_poll_complete(&cq->iop);
85 if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
86 irq_poll_sched(&cq->iop);
87 }
88
89 return completed;
90}
91
92static void ib_cq_completion_softirq(struct ib_cq *cq, void *private)
93{
94 irq_poll_sched(&cq->iop);
95}
96
97static void ib_cq_poll_work(struct work_struct *work)
98{
99 struct ib_cq *cq = container_of(work, struct ib_cq, work);
100 int completed;
101
102 completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);
103 if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
104 ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
105 queue_work(ib_comp_wq, &cq->work);
106}
107
108static void ib_cq_completion_workqueue(struct ib_cq *cq, void *private)
109{
110 queue_work(ib_comp_wq, &cq->work);
111}
112
113/**
114 * ib_alloc_cq - allocate a completion queue
115 * @dev: device to allocate the CQ for
116 * @private: driver private data, accessible from cq->cq_context
117 * @nr_cqe: number of CQEs to allocate
118 * @comp_vector: HCA completion vectors for this CQ
119 * @poll_ctx: context to poll the CQ from.
120 *
121 * This is the proper interface to allocate a CQ for in-kernel users. A
122 * CQ allocated with this interface will automatically be polled from the
123 * specified context. The ULP needs must use wr->wr_cqe instead of wr->wr_id
124 * to use this CQ abstraction.
125 */
126struct ib_cq *ib_alloc_cq(struct ib_device *dev, void *private,
127 int nr_cqe, int comp_vector, enum ib_poll_context poll_ctx)
128{
129 struct ib_cq_init_attr cq_attr = {
130 .cqe = nr_cqe,
131 .comp_vector = comp_vector,
132 };
133 struct ib_cq *cq;
134 int ret = -ENOMEM;
135
136 cq = dev->create_cq(dev, &cq_attr, NULL, NULL);
137 if (IS_ERR(cq))
138 return cq;
139
140 cq->device = dev;
141 cq->uobject = NULL;
142 cq->event_handler = NULL;
143 cq->cq_context = private;
144 cq->poll_ctx = poll_ctx;
145 atomic_set(&cq->usecnt, 0);
146
147 cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL);
148 if (!cq->wc)
149 goto out_destroy_cq;
150
151 switch (cq->poll_ctx) {
152 case IB_POLL_DIRECT:
153 cq->comp_handler = ib_cq_completion_direct;
154 break;
155 case IB_POLL_SOFTIRQ:
156 cq->comp_handler = ib_cq_completion_softirq;
157
158 irq_poll_init(&cq->iop, IB_POLL_BUDGET_IRQ, ib_poll_handler);
159 ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
160 break;
161 case IB_POLL_WORKQUEUE:
162 cq->comp_handler = ib_cq_completion_workqueue;
163 INIT_WORK(&cq->work, ib_cq_poll_work);
164 ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
165 break;
166 default:
167 ret = -EINVAL;
168 goto out_free_wc;
169 }
170
171 return cq;
172
173out_free_wc:
174 kfree(cq->wc);
175out_destroy_cq:
176 cq->device->destroy_cq(cq);
177 return ERR_PTR(ret);
178}
179EXPORT_SYMBOL(ib_alloc_cq);
180
181/**
182 * ib_free_cq - free a completion queue
183 * @cq: completion queue to free.
184 */
185void ib_free_cq(struct ib_cq *cq)
186{
187 int ret;
188
189 if (WARN_ON_ONCE(atomic_read(&cq->usecnt)))
190 return;
191
192 switch (cq->poll_ctx) {
193 case IB_POLL_DIRECT:
194 break;
195 case IB_POLL_SOFTIRQ:
196 irq_poll_disable(&cq->iop);
197 break;
198 case IB_POLL_WORKQUEUE:
199 flush_work(&cq->work);
200 break;
201 default:
202 WARN_ON_ONCE(1);
203 }
204
205 kfree(cq->wc);
206 ret = cq->device->destroy_cq(cq);
207 WARN_ON_ONCE(ret);
208}
209EXPORT_SYMBOL(ib_free_cq);