Merge tag 'v3.3.7' into 3.3/master
[zen-stable.git] / drivers / infiniband / hw / ipath / ipath_cq.c
blob0416c6c0e126f3dd8728fe2518b0d1ce018ce6dc
1 /*
2 * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
3 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
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:
11 * Redistribution and use in source and binary forms, with or
12 * without modification, are permitted provided that the following
13 * conditions are met:
15 * - Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
17 * disclaimer.
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.
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.
34 #include <linux/err.h>
35 #include <linux/slab.h>
36 #include <linux/vmalloc.h>
38 #include "ipath_verbs.h"
40 /**
41 * ipath_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
46 * This may be called with qp->s_lock held.
48 void ipath_cq_enter(struct ipath_cq *cq, struct ib_wc *entry, int solicited)
50 struct ipath_cq_wc *wc;
51 unsigned long flags;
52 u32 head;
53 u32 next;
55 spin_lock_irqsave(&cq->lock, flags);
58 * Note that the head pointer might be writable by user processes.
59 * Take care to verify it is a sane value.
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;
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);
78 return;
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 = (__u32 __force) entry->ex.imm_data;
87 wc->uqueue[head].qp_num = entry->qp->qp_num;
88 wc->uqueue[head].src_qp = entry->src_qp;
89 wc->uqueue[head].wc_flags = entry->wc_flags;
90 wc->uqueue[head].pkey_index = entry->pkey_index;
91 wc->uqueue[head].slid = entry->slid;
92 wc->uqueue[head].sl = entry->sl;
93 wc->uqueue[head].dlid_path_bits = entry->dlid_path_bits;
94 wc->uqueue[head].port_num = entry->port_num;
95 /* Make sure entry is written before the head index. */
96 smp_wmb();
97 } else
98 wc->kqueue[head] = *entry;
99 wc->head = next;
101 if (cq->notify == IB_CQ_NEXT_COMP ||
102 (cq->notify == IB_CQ_SOLICITED && solicited)) {
103 cq->notify = IB_CQ_NONE;
104 cq->triggered++;
106 * This will cause send_complete() to be called in
107 * another thread.
109 tasklet_hi_schedule(&cq->comptask);
112 spin_unlock_irqrestore(&cq->lock, flags);
114 if (entry->status != IB_WC_SUCCESS)
115 to_idev(cq->ibcq.device)->n_wqe_errs++;
119 * ipath_poll_cq - poll for work completion entries
120 * @ibcq: the completion queue to poll
121 * @num_entries: the maximum number of entries to return
122 * @entry: pointer to array where work completions are placed
124 * Returns the number of completion entries polled.
126 * This may be called from interrupt context. Also called by ib_poll_cq()
127 * in the generic verbs code.
129 int ipath_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
131 struct ipath_cq *cq = to_icq(ibcq);
132 struct ipath_cq_wc *wc;
133 unsigned long flags;
134 int npolled;
135 u32 tail;
137 /* The kernel can only poll a kernel completion queue */
138 if (cq->ip) {
139 npolled = -EINVAL;
140 goto bail;
143 spin_lock_irqsave(&cq->lock, flags);
145 wc = cq->queue;
146 tail = wc->tail;
147 if (tail > (u32) cq->ibcq.cqe)
148 tail = (u32) cq->ibcq.cqe;
149 for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
150 if (tail == wc->head)
151 break;
152 /* The kernel doesn't need a RMB since it has the lock. */
153 *entry = wc->kqueue[tail];
154 if (tail >= cq->ibcq.cqe)
155 tail = 0;
156 else
157 tail++;
159 wc->tail = tail;
161 spin_unlock_irqrestore(&cq->lock, flags);
163 bail:
164 return npolled;
167 static void send_complete(unsigned long data)
169 struct ipath_cq *cq = (struct ipath_cq *)data;
172 * The completion handler will most likely rearm the notification
173 * and poll for all pending entries. If a new completion entry
174 * is added while we are in this routine, tasklet_hi_schedule()
175 * won't call us again until we return so we check triggered to
176 * see if we need to call the handler again.
178 for (;;) {
179 u8 triggered = cq->triggered;
181 cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
183 if (cq->triggered == triggered)
184 return;
189 * ipath_create_cq - create a completion queue
190 * @ibdev: the device this completion queue is attached to
191 * @entries: the minimum size of the completion queue
192 * @context: unused by the InfiniPath driver
193 * @udata: unused by the InfiniPath driver
195 * Returns a pointer to the completion queue or negative errno values
196 * for failure.
198 * Called by ib_create_cq() in the generic verbs code.
200 struct ib_cq *ipath_create_cq(struct ib_device *ibdev, int entries, int comp_vector,
201 struct ib_ucontext *context,
202 struct ib_udata *udata)
204 struct ipath_ibdev *dev = to_idev(ibdev);
205 struct ipath_cq *cq;
206 struct ipath_cq_wc *wc;
207 struct ib_cq *ret;
208 u32 sz;
210 if (entries < 1 || entries > ib_ipath_max_cqes) {
211 ret = ERR_PTR(-EINVAL);
212 goto done;
215 /* Allocate the completion queue structure. */
216 cq = kmalloc(sizeof(*cq), GFP_KERNEL);
217 if (!cq) {
218 ret = ERR_PTR(-ENOMEM);
219 goto done;
223 * Allocate the completion queue entries and head/tail pointers.
224 * This is allocated separately so that it can be resized and
225 * also mapped into user space.
226 * We need to use vmalloc() in order to support mmap and large
227 * numbers of entries.
229 sz = sizeof(*wc);
230 if (udata && udata->outlen >= sizeof(__u64))
231 sz += sizeof(struct ib_uverbs_wc) * (entries + 1);
232 else
233 sz += sizeof(struct ib_wc) * (entries + 1);
234 wc = vmalloc_user(sz);
235 if (!wc) {
236 ret = ERR_PTR(-ENOMEM);
237 goto bail_cq;
241 * Return the address of the WC as the offset to mmap.
242 * See ipath_mmap() for details.
244 if (udata && udata->outlen >= sizeof(__u64)) {
245 int err;
247 cq->ip = ipath_create_mmap_info(dev, sz, context, wc);
248 if (!cq->ip) {
249 ret = ERR_PTR(-ENOMEM);
250 goto bail_wc;
253 err = ib_copy_to_udata(udata, &cq->ip->offset,
254 sizeof(cq->ip->offset));
255 if (err) {
256 ret = ERR_PTR(err);
257 goto bail_ip;
259 } else
260 cq->ip = NULL;
262 spin_lock(&dev->n_cqs_lock);
263 if (dev->n_cqs_allocated == ib_ipath_max_cqs) {
264 spin_unlock(&dev->n_cqs_lock);
265 ret = ERR_PTR(-ENOMEM);
266 goto bail_ip;
269 dev->n_cqs_allocated++;
270 spin_unlock(&dev->n_cqs_lock);
272 if (cq->ip) {
273 spin_lock_irq(&dev->pending_lock);
274 list_add(&cq->ip->pending_mmaps, &dev->pending_mmaps);
275 spin_unlock_irq(&dev->pending_lock);
279 * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
280 * The number of entries should be >= the number requested or return
281 * an error.
283 cq->ibcq.cqe = entries;
284 cq->notify = IB_CQ_NONE;
285 cq->triggered = 0;
286 spin_lock_init(&cq->lock);
287 tasklet_init(&cq->comptask, send_complete, (unsigned long)cq);
288 wc->head = 0;
289 wc->tail = 0;
290 cq->queue = wc;
292 ret = &cq->ibcq;
294 goto done;
296 bail_ip:
297 kfree(cq->ip);
298 bail_wc:
299 vfree(wc);
300 bail_cq:
301 kfree(cq);
302 done:
303 return ret;
307 * ipath_destroy_cq - destroy a completion queue
308 * @ibcq: the completion queue to destroy.
310 * Returns 0 for success.
312 * Called by ib_destroy_cq() in the generic verbs code.
314 int ipath_destroy_cq(struct ib_cq *ibcq)
316 struct ipath_ibdev *dev = to_idev(ibcq->device);
317 struct ipath_cq *cq = to_icq(ibcq);
319 tasklet_kill(&cq->comptask);
320 spin_lock(&dev->n_cqs_lock);
321 dev->n_cqs_allocated--;
322 spin_unlock(&dev->n_cqs_lock);
323 if (cq->ip)
324 kref_put(&cq->ip->ref, ipath_release_mmap_info);
325 else
326 vfree(cq->queue);
327 kfree(cq);
329 return 0;
333 * ipath_req_notify_cq - change the notification type for a completion queue
334 * @ibcq: the completion queue
335 * @notify_flags: the type of notification to request
337 * Returns 0 for success.
339 * This may be called from interrupt context. Also called by
340 * ib_req_notify_cq() in the generic verbs code.
342 int ipath_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
344 struct ipath_cq *cq = to_icq(ibcq);
345 unsigned long flags;
346 int ret = 0;
348 spin_lock_irqsave(&cq->lock, flags);
350 * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow
351 * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2).
353 if (cq->notify != IB_CQ_NEXT_COMP)
354 cq->notify = notify_flags & IB_CQ_SOLICITED_MASK;
356 if ((notify_flags & IB_CQ_REPORT_MISSED_EVENTS) &&
357 cq->queue->head != cq->queue->tail)
358 ret = 1;
360 spin_unlock_irqrestore(&cq->lock, flags);
362 return ret;
366 * ipath_resize_cq - change the size of the CQ
367 * @ibcq: the completion queue
369 * Returns 0 for success.
371 int ipath_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
373 struct ipath_cq *cq = to_icq(ibcq);
374 struct ipath_cq_wc *old_wc;
375 struct ipath_cq_wc *wc;
376 u32 head, tail, n;
377 int ret;
378 u32 sz;
380 if (cqe < 1 || cqe > ib_ipath_max_cqes) {
381 ret = -EINVAL;
382 goto bail;
386 * Need to use vmalloc() if we want to support large #s of entries.
388 sz = sizeof(*wc);
389 if (udata && udata->outlen >= sizeof(__u64))
390 sz += sizeof(struct ib_uverbs_wc) * (cqe + 1);
391 else
392 sz += sizeof(struct ib_wc) * (cqe + 1);
393 wc = vmalloc_user(sz);
394 if (!wc) {
395 ret = -ENOMEM;
396 goto bail;
399 /* Check that we can write the offset to mmap. */
400 if (udata && udata->outlen >= sizeof(__u64)) {
401 __u64 offset = 0;
403 ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
404 if (ret)
405 goto bail_free;
408 spin_lock_irq(&cq->lock);
410 * Make sure head and tail are sane since they
411 * might be user writable.
413 old_wc = cq->queue;
414 head = old_wc->head;
415 if (head > (u32) cq->ibcq.cqe)
416 head = (u32) cq->ibcq.cqe;
417 tail = old_wc->tail;
418 if (tail > (u32) cq->ibcq.cqe)
419 tail = (u32) cq->ibcq.cqe;
420 if (head < tail)
421 n = cq->ibcq.cqe + 1 + head - tail;
422 else
423 n = head - tail;
424 if (unlikely((u32)cqe < n)) {
425 ret = -EINVAL;
426 goto bail_unlock;
428 for (n = 0; tail != head; n++) {
429 if (cq->ip)
430 wc->uqueue[n] = old_wc->uqueue[tail];
431 else
432 wc->kqueue[n] = old_wc->kqueue[tail];
433 if (tail == (u32) cq->ibcq.cqe)
434 tail = 0;
435 else
436 tail++;
438 cq->ibcq.cqe = cqe;
439 wc->head = n;
440 wc->tail = 0;
441 cq->queue = wc;
442 spin_unlock_irq(&cq->lock);
444 vfree(old_wc);
446 if (cq->ip) {
447 struct ipath_ibdev *dev = to_idev(ibcq->device);
448 struct ipath_mmap_info *ip = cq->ip;
450 ipath_update_mmap_info(dev, ip, sz, wc);
453 * Return the offset to mmap.
454 * See ipath_mmap() for details.
456 if (udata && udata->outlen >= sizeof(__u64)) {
457 ret = ib_copy_to_udata(udata, &ip->offset,
458 sizeof(ip->offset));
459 if (ret)
460 goto bail;
463 spin_lock_irq(&dev->pending_lock);
464 if (list_empty(&ip->pending_mmaps))
465 list_add(&ip->pending_mmaps, &dev->pending_mmaps);
466 spin_unlock_irq(&dev->pending_lock);
469 ret = 0;
470 goto bail;
472 bail_unlock:
473 spin_unlock_irq(&cq->lock);
474 bail_free:
475 vfree(wc);
476 bail:
477 return ret;