1 /*
2 * Copyright (c) 2006, 2007, 2008, 2010 QLogic Corporation. All rights reserved.
3 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
4 *
5 * This software is available to you under a choice of one of two
6 * licenses. You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
10 *
11 * Redistribution and use in source and binary forms, with or
12 * without modification, are permitted provided that the following
13 * conditions are met:
14 *
15 * - Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
17 * disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials
22 * provided with the distribution.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31 * SOFTWARE.
32 */
33
34 #include <linux/err.h>
35 #include <linux/slab.h>
36 #include <linux/vmalloc.h>
37
38 #include "qib_verbs.h"
39
40 /**
41 * qib_cq_enter - add a new entry to the completion queue
42 * @cq: completion queue
43 * @entry: work completion entry to add
44 * @sig: true if @entry is a solicitated entry
45 *
46 * This may be called with qp->s_lock held.
47 */
qib_cq_enter(struct qib_cq * cq,struct ib_wc * entry,int solicited)48 void qib_cq_enter(struct qib_cq *cq, struct ib_wc *entry, int solicited)
49 {
50 struct qib_cq_wc *wc;
51 unsigned long flags;
52 u32 head;
53 u32 next;
54
55 spin_lock_irqsave(&cq->lock, flags);
56
57 /*
58 * Note that the head pointer might be writable by user processes.
59 * Take care to verify it is a sane value.
60 */
61 wc = cq->queue;
62 head = wc->head;
63 if (head >= (unsigned) cq->ibcq.cqe) {
64 head = cq->ibcq.cqe;
65 next = 0;
66 } else
67 next = head + 1;
68 if (unlikely(next == wc->tail)) {
69 spin_unlock_irqrestore(&cq->lock, flags);
70 if (cq->ibcq.event_handler) {
71 struct ib_event ev;
72
73 ev.device = cq->ibcq.device;
74 ev.element.cq = &cq->ibcq;
75 ev.event = IB_EVENT_CQ_ERR;
76 cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
77 }
78 return;
79 }
80 if (cq->ip) {
81 wc->uqueue[head].wr_id = entry->wr_id;
82 wc->uqueue[head].status = entry->status;
83 wc->uqueue[head].opcode = entry->opcode;
84 wc->uqueue[head].vendor_err = entry->vendor_err;
85 wc->uqueue[head].byte_len = entry->byte_len;
86 wc->uqueue[head].ex.imm_data =
87 (__u32 __force)entry->ex.imm_data;
88 wc->uqueue[head].qp_num = entry->qp->qp_num;
89 wc->uqueue[head].src_qp = entry->src_qp;
90 wc->uqueue[head].wc_flags = entry->wc_flags;
91 wc->uqueue[head].pkey_index = entry->pkey_index;
92 wc->uqueue[head].slid = entry->slid;
93 wc->uqueue[head].sl = entry->sl;
94 wc->uqueue[head].dlid_path_bits = entry->dlid_path_bits;
95 wc->uqueue[head].port_num = entry->port_num;
96 /* Make sure entry is written before the head index. */
97 smp_wmb();
98 } else
99 wc->kqueue[head] = *entry;
100 wc->head = next;
101
102 if (cq->notify == IB_CQ_NEXT_COMP ||
103 (cq->notify == IB_CQ_SOLICITED &&
104 (solicited || entry->status != IB_WC_SUCCESS))) {
105 cq->notify = IB_CQ_NONE;
106 cq->triggered++;
107 /*
108 * This will cause send_complete() to be called in
109 * another thread.
110 */
111 queue_work(qib_cq_wq, &cq->comptask);
112 }
113
114 spin_unlock_irqrestore(&cq->lock, flags);
115 }
116
117 /**
118 * qib_poll_cq - poll for work completion entries
119 * @ibcq: the completion queue to poll
120 * @num_entries: the maximum number of entries to return
121 * @entry: pointer to array where work completions are placed
122 *
123 * Returns the number of completion entries polled.
124 *
125 * This may be called from interrupt context. Also called by ib_poll_cq()
126 * in the generic verbs code.
127 */
qib_poll_cq(struct ib_cq * ibcq,int num_entries,struct ib_wc * entry)128 int qib_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
129 {
130 struct qib_cq *cq = to_icq(ibcq);
131 struct qib_cq_wc *wc;
132 unsigned long flags;
133 int npolled;
134 u32 tail;
135
136 /* The kernel can only poll a kernel completion queue */
137 if (cq->ip) {
138 npolled = -EINVAL;
139 goto bail;
140 }
141
142 spin_lock_irqsave(&cq->lock, flags);
143
144 wc = cq->queue;
145 tail = wc->tail;
146 if (tail > (u32) cq->ibcq.cqe)
147 tail = (u32) cq->ibcq.cqe;
148 for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
149 if (tail == wc->head)
150 break;
151 /* The kernel doesn't need a RMB since it has the lock. */
152 *entry = wc->kqueue[tail];
153 if (tail >= cq->ibcq.cqe)
154 tail = 0;
155 else
156 tail++;
157 }
158 wc->tail = tail;
159
160 spin_unlock_irqrestore(&cq->lock, flags);
161
162 bail:
163 return npolled;
164 }
165
send_complete(struct work_struct * work)166 static void send_complete(struct work_struct *work)
167 {
168 struct qib_cq *cq = container_of(work, struct qib_cq, comptask);
169
170 /*
171 * The completion handler will most likely rearm the notification
172 * and poll for all pending entries. If a new completion entry
173 * is added while we are in this routine, queue_work()
174 * won't call us again until we return so we check triggered to
175 * see if we need to call the handler again.
176 */
177 for (;;) {
178 u8 triggered = cq->triggered;
179
180 /*
181 * IPoIB connected mode assumes the callback is from a
182 * soft IRQ. We simulate this by blocking "bottom halves".
183 * See the implementation for ipoib_cm_handle_tx_wc(),
184 * netif_tx_lock_bh() and netif_tx_lock().
185 */
186 local_bh_disable();
187 cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
188 local_bh_enable();
189
190 if (cq->triggered == triggered)
191 return;
192 }
193 }
194
195 /**
196 * qib_create_cq - create a completion queue
197 * @ibdev: the device this completion queue is attached to
198 * @entries: the minimum size of the completion queue
199 * @context: unused by the QLogic_IB driver
200 * @udata: user data for libibverbs.so
201 *
202 * Returns a pointer to the completion queue or negative errno values
203 * for failure.
204 *
205 * Called by ib_create_cq() in the generic verbs code.
206 */
qib_create_cq(struct ib_device * ibdev,int entries,int comp_vector,struct ib_ucontext * context,struct ib_udata * udata)207 struct ib_cq *qib_create_cq(struct ib_device *ibdev, int entries,
208 int comp_vector, struct ib_ucontext *context,
209 struct ib_udata *udata)
210 {
211 struct qib_ibdev *dev = to_idev(ibdev);
212 struct qib_cq *cq;
213 struct qib_cq_wc *wc;
214 struct ib_cq *ret;
215 u32 sz;
216
217 if (entries < 1 || entries > ib_qib_max_cqes) {
218 ret = ERR_PTR(-EINVAL);
219 goto done;
220 }
221
222 /* Allocate the completion queue structure. */
223 cq = kmalloc(sizeof(*cq), GFP_KERNEL);
224 if (!cq) {
225 ret = ERR_PTR(-ENOMEM);
226 goto done;
227 }
228
229 /*
230 * Allocate the completion queue entries and head/tail pointers.
231 * This is allocated separately so that it can be resized and
232 * also mapped into user space.
233 * We need to use vmalloc() in order to support mmap and large
234 * numbers of entries.
235 */
236 sz = sizeof(*wc);
237 if (udata && udata->outlen >= sizeof(__u64))
238 sz += sizeof(struct ib_uverbs_wc) * (entries + 1);
239 else
240 sz += sizeof(struct ib_wc) * (entries + 1);
241 wc = vmalloc_user(sz);
242 if (!wc) {
243 ret = ERR_PTR(-ENOMEM);
244 goto bail_cq;
245 }
246
247 /*
248 * Return the address of the WC as the offset to mmap.
249 * See qib_mmap() for details.
250 */
251 if (udata && udata->outlen >= sizeof(__u64)) {
252 int err;
253
254 cq->ip = qib_create_mmap_info(dev, sz, context, wc);
255 if (!cq->ip) {
256 ret = ERR_PTR(-ENOMEM);
257 goto bail_wc;
258 }
259
260 err = ib_copy_to_udata(udata, &cq->ip->offset,
261 sizeof(cq->ip->offset));
262 if (err) {
263 ret = ERR_PTR(err);
264 goto bail_ip;
265 }
266 } else
267 cq->ip = NULL;
268
269 spin_lock(&dev->n_cqs_lock);
270 if (dev->n_cqs_allocated == ib_qib_max_cqs) {
271 spin_unlock(&dev->n_cqs_lock);
272 ret = ERR_PTR(-ENOMEM);
273 goto bail_ip;
274 }
275
276 dev->n_cqs_allocated++;
277 spin_unlock(&dev->n_cqs_lock);
278
279 if (cq->ip) {
280 spin_lock_irq(&dev->pending_lock);
281 list_add(&cq->ip->pending_mmaps, &dev->pending_mmaps);
282 spin_unlock_irq(&dev->pending_lock);
283 }
284
285 /*
286 * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
287 * The number of entries should be >= the number requested or return
288 * an error.
289 */
290 cq->ibcq.cqe = entries;
291 cq->notify = IB_CQ_NONE;
292 cq->triggered = 0;
293 spin_lock_init(&cq->lock);
294 INIT_WORK(&cq->comptask, send_complete);
295 wc->head = 0;
296 wc->tail = 0;
297 cq->queue = wc;
298
299 ret = &cq->ibcq;
300
301 goto done;
302
303 bail_ip:
304 kfree(cq->ip);
305 bail_wc:
306 vfree(wc);
307 bail_cq:
308 kfree(cq);
309 done:
310 return ret;
311 }
312
313 /**
314 * qib_destroy_cq - destroy a completion queue
315 * @ibcq: the completion queue to destroy.
316 *
317 * Returns 0 for success.
318 *
319 * Called by ib_destroy_cq() in the generic verbs code.
320 */
qib_destroy_cq(struct ib_cq * ibcq)321 int qib_destroy_cq(struct ib_cq *ibcq)
322 {
323 struct qib_ibdev *dev = to_idev(ibcq->device);
324 struct qib_cq *cq = to_icq(ibcq);
325
326 flush_work(&cq->comptask);
327 spin_lock(&dev->n_cqs_lock);
328 dev->n_cqs_allocated--;
329 spin_unlock(&dev->n_cqs_lock);
330 if (cq->ip)
331 kref_put(&cq->ip->ref, qib_release_mmap_info);
332 else
333 vfree(cq->queue);
334 kfree(cq);
335
336 return 0;
337 }
338
339 /**
340 * qib_req_notify_cq - change the notification type for a completion queue
341 * @ibcq: the completion queue
342 * @notify_flags: the type of notification to request
343 *
344 * Returns 0 for success.
345 *
346 * This may be called from interrupt context. Also called by
347 * ib_req_notify_cq() in the generic verbs code.
348 */
qib_req_notify_cq(struct ib_cq * ibcq,enum ib_cq_notify_flags notify_flags)349 int qib_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
350 {
351 struct qib_cq *cq = to_icq(ibcq);
352 unsigned long flags;
353 int ret = 0;
354
355 spin_lock_irqsave(&cq->lock, flags);
356 /*
357 * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow
358 * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2).
359 */
360 if (cq->notify != IB_CQ_NEXT_COMP)
361 cq->notify = notify_flags & IB_CQ_SOLICITED_MASK;
362
363 if ((notify_flags & IB_CQ_REPORT_MISSED_EVENTS) &&
364 cq->queue->head != cq->queue->tail)
365 ret = 1;
366
367 spin_unlock_irqrestore(&cq->lock, flags);
368
369 return ret;
370 }
371
372 /**
373 * qib_resize_cq - change the size of the CQ
374 * @ibcq: the completion queue
375 *
376 * Returns 0 for success.
377 */
qib_resize_cq(struct ib_cq * ibcq,int cqe,struct ib_udata * udata)378 int qib_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
379 {
380 struct qib_cq *cq = to_icq(ibcq);
381 struct qib_cq_wc *old_wc;
382 struct qib_cq_wc *wc;
383 u32 head, tail, n;
384 int ret;
385 u32 sz;
386
387 if (cqe < 1 || cqe > ib_qib_max_cqes) {
388 ret = -EINVAL;
389 goto bail;
390 }
391
392 /*
393 * Need to use vmalloc() if we want to support large #s of entries.
394 */
395 sz = sizeof(*wc);
396 if (udata && udata->outlen >= sizeof(__u64))
397 sz += sizeof(struct ib_uverbs_wc) * (cqe + 1);
398 else
399 sz += sizeof(struct ib_wc) * (cqe + 1);
400 wc = vmalloc_user(sz);
401 if (!wc) {
402 ret = -ENOMEM;
403 goto bail;
404 }
405
406 /* Check that we can write the offset to mmap. */
407 if (udata && udata->outlen >= sizeof(__u64)) {
408 __u64 offset = 0;
409
410 ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
411 if (ret)
412 goto bail_free;
413 }
414
415 spin_lock_irq(&cq->lock);
416 /*
417 * Make sure head and tail are sane since they
418 * might be user writable.
419 */
420 old_wc = cq->queue;
421 head = old_wc->head;
422 if (head > (u32) cq->ibcq.cqe)
423 head = (u32) cq->ibcq.cqe;
424 tail = old_wc->tail;
425 if (tail > (u32) cq->ibcq.cqe)
426 tail = (u32) cq->ibcq.cqe;
427 if (head < tail)
428 n = cq->ibcq.cqe + 1 + head - tail;
429 else
430 n = head - tail;
431 if (unlikely((u32)cqe < n)) {
432 ret = -EINVAL;
433 goto bail_unlock;
434 }
435 for (n = 0; tail != head; n++) {
436 if (cq->ip)
437 wc->uqueue[n] = old_wc->uqueue[tail];
438 else
439 wc->kqueue[n] = old_wc->kqueue[tail];
440 if (tail == (u32) cq->ibcq.cqe)
441 tail = 0;
442 else
443 tail++;
444 }
445 cq->ibcq.cqe = cqe;
446 wc->head = n;
447 wc->tail = 0;
448 cq->queue = wc;
449 spin_unlock_irq(&cq->lock);
450
451 vfree(old_wc);
452
453 if (cq->ip) {
454 struct qib_ibdev *dev = to_idev(ibcq->device);
455 struct qib_mmap_info *ip = cq->ip;
456
457 qib_update_mmap_info(dev, ip, sz, wc);
458
459 /*
460 * Return the offset to mmap.
461 * See qib_mmap() for details.
462 */
463 if (udata && udata->outlen >= sizeof(__u64)) {
464 ret = ib_copy_to_udata(udata, &ip->offset,
465 sizeof(ip->offset));
466 if (ret)
467 goto bail;
468 }
469
470 spin_lock_irq(&dev->pending_lock);
471 if (list_empty(&ip->pending_mmaps))
472 list_add(&ip->pending_mmaps, &dev->pending_mmaps);
473 spin_unlock_irq(&dev->pending_lock);
474 }
475
476 ret = 0;
477 goto bail;
478
479 bail_unlock:
480 spin_unlock_irq(&cq->lock);
481 bail_free:
482 vfree(wc);
483 bail:
484 return ret;
485 }
486