drivers/infiniband/hw/qib/qib_cq.c

   1 /*
   2  * Copyright (c) 2013 Intel Corporation.  All rights reserved.
   3  * Copyright (c) 2006, 2007, 2008, 2010 QLogic Corporation. All rights reserved.
   4  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  */
  34
  35 #include <linux/err.h>
  36 #include <linux/slab.h>
  37 #include <linux/vmalloc.h>
  38 #include <linux/kthread.h>
  39
  40 #include "qib_verbs.h"
  41 #include "qib.h"
  42
  43 /**
  44  * qib_cq_enter - add a new entry to the completion queue
  45  * @cq: completion queue
  46  * @entry: work completion entry to add
  47  * @sig: true if @entry is a solicitated entry
  48  *
  49  * This may be called with qp->s_lock held.
  50  */
  51 void qib_cq_enter(struct qib_cq *cq, struct ib_wc *entry, int solicited)
  52 {
  53         struct qib_cq_wc *wc;
  54         unsigned long flags;
  55         u32 head;
  56         u32 next;
  57
  58         spin_lock_irqsave(&cq->lock, flags);
  59
  60         /*
  61          * Note that the head pointer might be writable by user processes.
  62          * Take care to verify it is a sane value.
  63          */
  64         wc = cq->queue;
  65         head = wc->head;
  66         if (head >= (unsigned) cq->ibcq.cqe) {
  67                 head = cq->ibcq.cqe;
  68                 next = 0;
  69         } else
  70                 next = head + 1;
  71         if (unlikely(next == wc->tail)) {
  72                 spin_unlock_irqrestore(&cq->lock, flags);
  73                 if (cq->ibcq.event_handler) {
  74                         struct ib_event ev;
  75
  76                         ev.device = cq->ibcq.device;
  77                         ev.element.cq = &cq->ibcq;
  78                         ev.event = IB_EVENT_CQ_ERR;
  79                         cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
  80                 }
  81                 return;
  82         }
  83         if (cq->ip) {
  84                 wc->uqueue[head].wr_id = entry->wr_id;
  85                 wc->uqueue[head].status = entry->status;
  86                 wc->uqueue[head].opcode = entry->opcode;
  87                 wc->uqueue[head].vendor_err = entry->vendor_err;
  88                 wc->uqueue[head].byte_len = entry->byte_len;
  89                 wc->uqueue[head].ex.imm_data =
  90                         (__u32 __force)entry->ex.imm_data;
  91                 wc->uqueue[head].qp_num = entry->qp->qp_num;
  92                 wc->uqueue[head].src_qp = entry->src_qp;
  93                 wc->uqueue[head].wc_flags = entry->wc_flags;
  94                 wc->uqueue[head].pkey_index = entry->pkey_index;
  95                 wc->uqueue[head].slid = entry->slid;
  96                 wc->uqueue[head].sl = entry->sl;
  97                 wc->uqueue[head].dlid_path_bits = entry->dlid_path_bits;
  98                 wc->uqueue[head].port_num = entry->port_num;
  99                 /* Make sure entry is written before the head index. */
 100                 smp_wmb();
 101         } else
 102                 wc->kqueue[head] = *entry;
 103         wc->head = next;
 104
 105         if (cq->notify == IB_CQ_NEXT_COMP ||
 106             (cq->notify == IB_CQ_SOLICITED &&
 107              (solicited || entry->status != IB_WC_SUCCESS))) {
 108                 struct kthread_worker *worker;
 109                 /*
 110                  * This will cause send_complete() to be called in
 111                  * another thread.
 112                  */
 113                 smp_rmb();
 114                 worker = cq->dd->worker;
 115                 if (likely(worker)) {
 116                         cq->notify = IB_CQ_NONE;
 117                         cq->triggered++;
 118                         queue_kthread_work(worker, &cq->comptask);
 119                 }
 120         }
 121
 122         spin_unlock_irqrestore(&cq->lock, flags);
 123 }
 124
 125 /**
 126  * qib_poll_cq - poll for work completion entries
 127  * @ibcq: the completion queue to poll
 128  * @num_entries: the maximum number of entries to return
 129  * @entry: pointer to array where work completions are placed
 130  *
 131  * Returns the number of completion entries polled.
 132  *
 133  * This may be called from interrupt context.  Also called by ib_poll_cq()
 134  * in the generic verbs code.
 135  */
 136 int qib_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
 137 {
 138         struct qib_cq *cq = to_icq(ibcq);
 139         struct qib_cq_wc *wc;
 140         unsigned long flags;
 141         int npolled;
 142         u32 tail;
 143
 144         /* The kernel can only poll a kernel completion queue */
 145         if (cq->ip) {
 146                 npolled = -EINVAL;
 147                 goto bail;
 148         }
 149
 150         spin_lock_irqsave(&cq->lock, flags);
 151
 152         wc = cq->queue;
 153         tail = wc->tail;
 154         if (tail > (u32) cq->ibcq.cqe)
 155                 tail = (u32) cq->ibcq.cqe;
 156         for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
 157                 if (tail == wc->head)
 158                         break;
 159                 /* The kernel doesn't need a RMB since it has the lock. */
 160                 *entry = wc->kqueue[tail];
 161                 if (tail >= cq->ibcq.cqe)
 162                         tail = 0;
 163                 else
 164                         tail++;
 165         }
 166         wc->tail = tail;
 167
 168         spin_unlock_irqrestore(&cq->lock, flags);
 169
 170 bail:
 171         return npolled;
 172 }
 173
 174 static void send_complete(struct kthread_work *work)
 175 {
 176         struct qib_cq *cq = container_of(work, struct qib_cq, comptask);
 177
 178         /*
 179          * The completion handler will most likely rearm the notification
 180          * and poll for all pending entries.  If a new completion entry
 181          * is added while we are in this routine, queue_work()
 182          * won't call us again until we return so we check triggered to
 183          * see if we need to call the handler again.
 184          */
 185         for (;;) {
 186                 u8 triggered = cq->triggered;
 187
 188                 /*
 189                  * IPoIB connected mode assumes the callback is from a
 190                  * soft IRQ. We simulate this by blocking "bottom halves".
 191                  * See the implementation for ipoib_cm_handle_tx_wc(),
 192                  * netif_tx_lock_bh() and netif_tx_lock().
 193                  */
 194                 local_bh_disable();
 195                 cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
 196                 local_bh_enable();
 197
 198                 if (cq->triggered == triggered)
 199                         return;
 200         }
 201 }
 202
 203 /**
 204  * qib_create_cq - create a completion queue
 205  * @ibdev: the device this completion queue is attached to
 206  * @entries: the minimum size of the completion queue
 207  * @context: unused by the QLogic_IB driver
 208  * @udata: user data for libibverbs.so
 209  *
 210  * Returns a pointer to the completion queue or negative errno values
 211  * for failure.
 212  *
 213  * Called by ib_create_cq() in the generic verbs code.
 214  */
 215 struct ib_cq *qib_create_cq(struct ib_device *ibdev, int entries,
 216                             int comp_vector, struct ib_ucontext *context,
 217                             struct ib_udata *udata)
 218 {
 219         struct qib_ibdev *dev = to_idev(ibdev);
 220         struct qib_cq *cq;
 221         struct qib_cq_wc *wc;
 222         struct ib_cq *ret;
 223         u32 sz;
 224
 225         if (entries < 1 || entries > ib_qib_max_cqes) {
 226                 ret = ERR_PTR(-EINVAL);
 227                 goto done;
 228         }
 229
 230         /* Allocate the completion queue structure. */
 231         cq = kmalloc(sizeof(*cq), GFP_KERNEL);
 232         if (!cq) {
 233                 ret = ERR_PTR(-ENOMEM);
 234                 goto done;
 235         }
 236
 237         /*
 238          * Allocate the completion queue entries and head/tail pointers.
 239          * This is allocated separately so that it can be resized and
 240          * also mapped into user space.
 241          * We need to use vmalloc() in order to support mmap and large
 242          * numbers of entries.
 243          */
 244         sz = sizeof(*wc);
 245         if (udata && udata->outlen >= sizeof(__u64))
 246                 sz += sizeof(struct ib_uverbs_wc) * (entries + 1);
 247         else
 248                 sz += sizeof(struct ib_wc) * (entries + 1);
 249         wc = vmalloc_user(sz);
 250         if (!wc) {
 251                 ret = ERR_PTR(-ENOMEM);
 252                 goto bail_cq;
 253         }
 254
 255         /*
 256          * Return the address of the WC as the offset to mmap.
 257          * See qib_mmap() for details.
 258          */
 259         if (udata && udata->outlen >= sizeof(__u64)) {
 260                 int err;
 261
 262                 cq->ip = qib_create_mmap_info(dev, sz, context, wc);
 263                 if (!cq->ip) {
 264                         ret = ERR_PTR(-ENOMEM);
 265                         goto bail_wc;
 266                 }
 267
 268                 err = ib_copy_to_udata(udata, &cq->ip->offset,
 269                                        sizeof(cq->ip->offset));
 270                 if (err) {
 271                         ret = ERR_PTR(err);
 272                         goto bail_ip;
 273                 }
 274         } else
 275                 cq->ip = NULL;
 276
 277         spin_lock(&dev->n_cqs_lock);
 278         if (dev->n_cqs_allocated == ib_qib_max_cqs) {
 279                 spin_unlock(&dev->n_cqs_lock);
 280                 ret = ERR_PTR(-ENOMEM);
 281                 goto bail_ip;
 282         }
 283
 284         dev->n_cqs_allocated++;
 285         spin_unlock(&dev->n_cqs_lock);
 286
 287         if (cq->ip) {
 288                 spin_lock_irq(&dev->pending_lock);
 289                 list_add(&cq->ip->pending_mmaps, &dev->pending_mmaps);
 290                 spin_unlock_irq(&dev->pending_lock);
 291         }
 292
 293         /*
 294          * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
 295          * The number of entries should be >= the number requested or return
 296          * an error.
 297          */
 298         cq->dd = dd_from_dev(dev);
 299         cq->ibcq.cqe = entries;
 300         cq->notify = IB_CQ_NONE;
 301         cq->triggered = 0;
 302         spin_lock_init(&cq->lock);
 303         init_kthread_work(&cq->comptask, send_complete);
 304         wc->head = 0;
 305         wc->tail = 0;
 306         cq->queue = wc;
 307
 308         ret = &cq->ibcq;
 309
 310         goto done;
 311
 312 bail_ip:
 313         kfree(cq->ip);
 314 bail_wc:
 315         vfree(wc);
 316 bail_cq:
 317         kfree(cq);
 318 done:
 319         return ret;
 320 }
 321
 322 /**
 323  * qib_destroy_cq - destroy a completion queue
 324  * @ibcq: the completion queue to destroy.
 325  *
 326  * Returns 0 for success.
 327  *
 328  * Called by ib_destroy_cq() in the generic verbs code.
 329  */
 330 int qib_destroy_cq(struct ib_cq *ibcq)
 331 {
 332         struct qib_ibdev *dev = to_idev(ibcq->device);
 333         struct qib_cq *cq = to_icq(ibcq);
 334
 335         flush_kthread_work(&cq->comptask);
 336         spin_lock(&dev->n_cqs_lock);
 337         dev->n_cqs_allocated--;
 338         spin_unlock(&dev->n_cqs_lock);
 339         if (cq->ip)
 340                 kref_put(&cq->ip->ref, qib_release_mmap_info);
 341         else
 342                 vfree(cq->queue);
 343         kfree(cq);
 344
 345         return 0;
 346 }
 347
 348 /**
 349  * qib_req_notify_cq - change the notification type for a completion queue
 350  * @ibcq: the completion queue
 351  * @notify_flags: the type of notification to request
 352  *
 353  * Returns 0 for success.
 354  *
 355  * This may be called from interrupt context.  Also called by
 356  * ib_req_notify_cq() in the generic verbs code.
 357  */
 358 int qib_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
 359 {
 360         struct qib_cq *cq = to_icq(ibcq);
 361         unsigned long flags;
 362         int ret = 0;
 363
 364         spin_lock_irqsave(&cq->lock, flags);
 365         /*
 366          * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow
 367          * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2).
 368          */
 369         if (cq->notify != IB_CQ_NEXT_COMP)
 370                 cq->notify = notify_flags & IB_CQ_SOLICITED_MASK;
 371
 372         if ((notify_flags & IB_CQ_REPORT_MISSED_EVENTS) &&
 373             cq->queue->head != cq->queue->tail)
 374                 ret = 1;
 375
 376         spin_unlock_irqrestore(&cq->lock, flags);
 377
 378         return ret;
 379 }
 380
 381 /**
 382  * qib_resize_cq - change the size of the CQ
 383  * @ibcq: the completion queue
 384  *
 385  * Returns 0 for success.
 386  */
 387 int qib_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
 388 {
 389         struct qib_cq *cq = to_icq(ibcq);
 390         struct qib_cq_wc *old_wc;
 391         struct qib_cq_wc *wc;
 392         u32 head, tail, n;
 393         int ret;
 394         u32 sz;
 395
 396         if (cqe < 1 || cqe > ib_qib_max_cqes) {
 397                 ret = -EINVAL;
 398                 goto bail;
 399         }
 400
 401         /*
 402          * Need to use vmalloc() if we want to support large #s of entries.
 403          */
 404         sz = sizeof(*wc);
 405         if (udata && udata->outlen >= sizeof(__u64))
 406                 sz += sizeof(struct ib_uverbs_wc) * (cqe + 1);
 407         else
 408                 sz += sizeof(struct ib_wc) * (cqe + 1);
 409         wc = vmalloc_user(sz);
 410         if (!wc) {
 411                 ret = -ENOMEM;
 412                 goto bail;
 413         }
 414
 415         /* Check that we can write the offset to mmap. */
 416         if (udata && udata->outlen >= sizeof(__u64)) {
 417                 __u64 offset = 0;
 418
 419                 ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
 420                 if (ret)
 421                         goto bail_free;
 422         }
 423
 424         spin_lock_irq(&cq->lock);
 425         /*
 426          * Make sure head and tail are sane since they
 427          * might be user writable.
 428          */
 429         old_wc = cq->queue;
 430         head = old_wc->head;
 431         if (head > (u32) cq->ibcq.cqe)
 432                 head = (u32) cq->ibcq.cqe;
 433         tail = old_wc->tail;
 434         if (tail > (u32) cq->ibcq.cqe)
 435                 tail = (u32) cq->ibcq.cqe;
 436         if (head < tail)
 437                 n = cq->ibcq.cqe + 1 + head - tail;
 438         else
 439                 n = head - tail;
 440         if (unlikely((u32)cqe < n)) {
 441                 ret = -EINVAL;
 442                 goto bail_unlock;
 443         }
 444         for (n = 0; tail != head; n++) {
 445                 if (cq->ip)
 446                         wc->uqueue[n] = old_wc->uqueue[tail];
 447                 else
 448                         wc->kqueue[n] = old_wc->kqueue[tail];
 449                 if (tail == (u32) cq->ibcq.cqe)
 450                         tail = 0;
 451                 else
 452                         tail++;
 453         }
 454         cq->ibcq.cqe = cqe;
 455         wc->head = n;
 456         wc->tail = 0;
 457         cq->queue = wc;
 458         spin_unlock_irq(&cq->lock);
 459
 460         vfree(old_wc);
 461
 462         if (cq->ip) {
 463                 struct qib_ibdev *dev = to_idev(ibcq->device);
 464                 struct qib_mmap_info *ip = cq->ip;
 465
 466                 qib_update_mmap_info(dev, ip, sz, wc);
 467
 468                 /*
 469                  * Return the offset to mmap.
 470                  * See qib_mmap() for details.
 471                  */
 472                 if (udata && udata->outlen >= sizeof(__u64)) {
 473                         ret = ib_copy_to_udata(udata, &ip->offset,
 474                                                sizeof(ip->offset));
 475                         if (ret)
 476                                 goto bail;
 477                 }
 478
 479                 spin_lock_irq(&dev->pending_lock);
 480                 if (list_empty(&ip->pending_mmaps))
 481                         list_add(&ip->pending_mmaps, &dev->pending_mmaps);
 482                 spin_unlock_irq(&dev->pending_lock);
 483         }
 484
 485         ret = 0;
 486         goto bail;
 487
 488 bail_unlock:
 489         spin_unlock_irq(&cq->lock);
 490 bail_free:
 491         vfree(wc);
 492 bail:
 493         return ret;
 494 }
 495
 496 int qib_cq_init(struct qib_devdata *dd)
 497 {
 498         int ret = 0;
 499         int cpu;
 500         struct task_struct *task;
 501
 502         if (dd->worker)
 503                 return 0;
 504         dd->worker = kzalloc(sizeof(*dd->worker), GFP_KERNEL);
 505         if (!dd->worker)
 506                 return -ENOMEM;
 507         init_kthread_worker(dd->worker);
 508         task = kthread_create_on_node(
 509                 kthread_worker_fn,
 510                 dd->worker,
 511                 dd->assigned_node_id,
 512                 "qib_cq%d", dd->unit);
 513         if (IS_ERR(task))
 514                 goto task_fail;
 515         cpu = cpumask_first(cpumask_of_node(dd->assigned_node_id));
 516         kthread_bind(task, cpu);
 517         wake_up_process(task);
 518 out:
 519         return ret;
 520 task_fail:
 521         ret = PTR_ERR(task);
 522         kfree(dd->worker);
 523         dd->worker = NULL;
 524         goto out;
 525 }
 526
 527 void qib_cq_exit(struct qib_devdata *dd)
 528 {
 529         struct kthread_worker *worker;
 530
 531         worker = dd->worker;
 532         if (!worker)
 533                 return;
 534         /* blocks future queuing from send_complete() */
 535         dd->worker = NULL;
 536         smp_wmb();
 537         flush_kthread_worker(worker);
 538         kthread_stop(worker->task);
 539         kfree(worker);
 540 }