drivers/infiniband/hw/qib/qib_cq.c

   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  */
  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  */
 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
 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  */
 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  */
 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  */
 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  */
 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 }