drivers/infiniband/hw/ipath/ipath_cq.c

   1 /*
   2  * Copyright (c) 2006 QLogic, Inc. 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/vmalloc.h>
  36
  37 #include "ipath_verbs.h"
  38
  39 /**
  40  * ipath_cq_enter - add a new entry to the completion queue
  41  * @cq: completion queue
  42  * @entry: work completion entry to add
  43  * @sig: true if @entry is a solicitated entry
  44  *
  45  * This may be called with qp->s_lock held.
  46  */
  47 void ipath_cq_enter(struct ipath_cq *cq, struct ib_wc *entry, int solicited)
  48 {
  49         struct ipath_cq_wc *wc;
  50         unsigned long flags;
  51         u32 head;
  52         u32 next;
  53
  54         spin_lock_irqsave(&cq->lock, flags);
  55
  56         /*
  57          * Note that the head pointer might be writable by user processes.
  58          * Take care to verify it is a sane value.
  59          */
  60         wc = cq->queue;
  61         head = wc->head;
  62         if (head >= (unsigned) cq->ibcq.cqe) {
  63                 head = cq->ibcq.cqe;
  64                 next = 0;
  65         } else
  66                 next = head + 1;
  67         if (unlikely(next == wc->tail)) {
  68                 spin_unlock_irqrestore(&cq->lock, flags);
  69                 if (cq->ibcq.event_handler) {
  70                         struct ib_event ev;
  71
  72                         ev.device = cq->ibcq.device;
  73                         ev.element.cq = &cq->ibcq;
  74                         ev.event = IB_EVENT_CQ_ERR;
  75                         cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
  76                 }
  77                 return;
  78         }
  79         wc->queue[head].wr_id = entry->wr_id;
  80         wc->queue[head].status = entry->status;
  81         wc->queue[head].opcode = entry->opcode;
  82         wc->queue[head].vendor_err = entry->vendor_err;
  83         wc->queue[head].byte_len = entry->byte_len;
  84         wc->queue[head].imm_data = (__u32 __force)entry->imm_data;
  85         wc->queue[head].qp_num = entry->qp->qp_num;
  86         wc->queue[head].src_qp = entry->src_qp;
  87         wc->queue[head].wc_flags = entry->wc_flags;
  88         wc->queue[head].pkey_index = entry->pkey_index;
  89         wc->queue[head].slid = entry->slid;
  90         wc->queue[head].sl = entry->sl;
  91         wc->queue[head].dlid_path_bits = entry->dlid_path_bits;
  92         wc->queue[head].port_num = entry->port_num;
  93         wc->head = next;
  94
  95         if (cq->notify == IB_CQ_NEXT_COMP ||
  96             (cq->notify == IB_CQ_SOLICITED && solicited)) {
  97                 cq->notify = IB_CQ_NONE;
  98                 cq->triggered++;
  99                 /*
 100                  * This will cause send_complete() to be called in
 101                  * another thread.
 102                  */
 103                 tasklet_hi_schedule(&cq->comptask);
 104         }
 105
 106         spin_unlock_irqrestore(&cq->lock, flags);
 107
 108         if (entry->status != IB_WC_SUCCESS)
 109                 to_idev(cq->ibcq.device)->n_wqe_errs++;
 110 }
 111
 112 /**
 113  * ipath_poll_cq - poll for work completion entries
 114  * @ibcq: the completion queue to poll
 115  * @num_entries: the maximum number of entries to return
 116  * @entry: pointer to array where work completions are placed
 117  *
 118  * Returns the number of completion entries polled.
 119  *
 120  * This may be called from interrupt context.  Also called by ib_poll_cq()
 121  * in the generic verbs code.
 122  */
 123 int ipath_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
 124 {
 125         struct ipath_cq *cq = to_icq(ibcq);
 126         struct ipath_cq_wc *wc;
 127         unsigned long flags;
 128         int npolled;
 129         u32 tail;
 130
 131         spin_lock_irqsave(&cq->lock, flags);
 132
 133         wc = cq->queue;
 134         tail = wc->tail;
 135         if (tail > (u32) cq->ibcq.cqe)
 136                 tail = (u32) cq->ibcq.cqe;
 137         for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
 138                 struct ipath_qp *qp;
 139
 140                 if (tail == wc->head)
 141                         break;
 142
 143                 qp = ipath_lookup_qpn(&to_idev(cq->ibcq.device)->qp_table,
 144                                       wc->queue[tail].qp_num);
 145                 entry->qp = &qp->ibqp;
 146                 if (atomic_dec_and_test(&qp->refcount))
 147                         wake_up(&qp->wait);
 148
 149                 entry->wr_id = wc->queue[tail].wr_id;
 150                 entry->status = wc->queue[tail].status;
 151                 entry->opcode = wc->queue[tail].opcode;
 152                 entry->vendor_err = wc->queue[tail].vendor_err;
 153                 entry->byte_len = wc->queue[tail].byte_len;
 154                 entry->imm_data = wc->queue[tail].imm_data;
 155                 entry->src_qp = wc->queue[tail].src_qp;
 156                 entry->wc_flags = wc->queue[tail].wc_flags;
 157                 entry->pkey_index = wc->queue[tail].pkey_index;
 158                 entry->slid = wc->queue[tail].slid;
 159                 entry->sl = wc->queue[tail].sl;
 160                 entry->dlid_path_bits = wc->queue[tail].dlid_path_bits;
 161                 entry->port_num = wc->queue[tail].port_num;
 162                 if (tail >= cq->ibcq.cqe)
 163                         tail = 0;
 164                 else
 165                         tail++;
 166         }
 167         wc->tail = tail;
 168
 169         spin_unlock_irqrestore(&cq->lock, flags);
 170
 171         return npolled;
 172 }
 173
 174 static void send_complete(unsigned long data)
 175 {
 176         struct ipath_cq *cq = (struct ipath_cq *)data;
 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, tasklet_hi_schedule()
 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                 cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
 189
 190                 if (cq->triggered == triggered)
 191                         return;
 192         }
 193 }
 194
 195 /**
 196  * ipath_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 InfiniPath driver
 200  * @udata: unused by the InfiniPath driver
 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 *ipath_create_cq(struct ib_device *ibdev, int entries, int comp_vector,
 208                               struct ib_ucontext *context,
 209                               struct ib_udata *udata)
 210 {
 211         struct ipath_ibdev *dev = to_idev(ibdev);
 212         struct ipath_cq *cq;
 213         struct ipath_cq_wc *wc;
 214         struct ib_cq *ret;
 215
 216         if (entries < 1 || entries > ib_ipath_max_cqes) {
 217                 ret = ERR_PTR(-EINVAL);
 218                 goto done;
 219         }
 220
 221         /* Allocate the completion queue structure. */
 222         cq = kmalloc(sizeof(*cq), GFP_KERNEL);
 223         if (!cq) {
 224                 ret = ERR_PTR(-ENOMEM);
 225                 goto done;
 226         }
 227
 228         /*
 229          * Allocate the completion queue entries and head/tail pointers.
 230          * This is allocated separately so that it can be resized and
 231          * also mapped into user space.
 232          * We need to use vmalloc() in order to support mmap and large
 233          * numbers of entries.
 234          */
 235         wc = vmalloc_user(sizeof(*wc) + sizeof(struct ib_wc) * entries);
 236         if (!wc) {
 237                 ret = ERR_PTR(-ENOMEM);
 238                 goto bail_cq;
 239         }
 240
 241         /*
 242          * Return the address of the WC as the offset to mmap.
 243          * See ipath_mmap() for details.
 244          */
 245         if (udata && udata->outlen >= sizeof(__u64)) {
 246                 int err;
 247                 u32 s = sizeof *wc + sizeof(struct ib_wc) * entries;
 248
 249                 cq->ip = ipath_create_mmap_info(dev, s, context, wc);
 250                 if (!cq->ip) {
 251                         ret = ERR_PTR(-ENOMEM);
 252                         goto bail_wc;
 253                 }
 254
 255                 err = ib_copy_to_udata(udata, &cq->ip->offset,
 256                                        sizeof(cq->ip->offset));
 257                 if (err) {
 258                         ret = ERR_PTR(err);
 259                         goto bail_ip;
 260                 }
 261         } else
 262                 cq->ip = NULL;
 263
 264         spin_lock(&dev->n_cqs_lock);
 265         if (dev->n_cqs_allocated == ib_ipath_max_cqs) {
 266                 spin_unlock(&dev->n_cqs_lock);
 267                 ret = ERR_PTR(-ENOMEM);
 268                 goto bail_ip;
 269         }
 270
 271         dev->n_cqs_allocated++;
 272         spin_unlock(&dev->n_cqs_lock);
 273
 274         if (cq->ip) {
 275                 spin_lock_irq(&dev->pending_lock);
 276                 list_add(&cq->ip->pending_mmaps, &dev->pending_mmaps);
 277                 spin_unlock_irq(&dev->pending_lock);
 278         }
 279
 280         /*
 281          * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
 282          * The number of entries should be >= the number requested or return
 283          * an error.
 284          */
 285         cq->ibcq.cqe = entries;
 286         cq->notify = IB_CQ_NONE;
 287         cq->triggered = 0;
 288         spin_lock_init(&cq->lock);
 289         tasklet_init(&cq->comptask, send_complete, (unsigned long)cq);
 290         wc->head = 0;
 291         wc->tail = 0;
 292         cq->queue = wc;
 293
 294         ret = &cq->ibcq;
 295
 296         goto done;
 297
 298 bail_ip:
 299         kfree(cq->ip);
 300 bail_wc:
 301         vfree(wc);
 302 bail_cq:
 303         kfree(cq);
 304 done:
 305         return ret;
 306 }
 307
 308 /**
 309  * ipath_destroy_cq - destroy a completion queue
 310  * @ibcq: the completion queue to destroy.
 311  *
 312  * Returns 0 for success.
 313  *
 314  * Called by ib_destroy_cq() in the generic verbs code.
 315  */
 316 int ipath_destroy_cq(struct ib_cq *ibcq)
 317 {
 318         struct ipath_ibdev *dev = to_idev(ibcq->device);
 319         struct ipath_cq *cq = to_icq(ibcq);
 320
 321         tasklet_kill(&cq->comptask);
 322         spin_lock(&dev->n_cqs_lock);
 323         dev->n_cqs_allocated--;
 324         spin_unlock(&dev->n_cqs_lock);
 325         if (cq->ip)
 326                 kref_put(&cq->ip->ref, ipath_release_mmap_info);
 327         else
 328                 vfree(cq->queue);
 329         kfree(cq);
 330
 331         return 0;
 332 }
 333
 334 /**
 335  * ipath_req_notify_cq - change the notification type for a completion queue
 336  * @ibcq: the completion queue
 337  * @notify_flags: the type of notification to request
 338  *
 339  * Returns 0 for success.
 340  *
 341  * This may be called from interrupt context.  Also called by
 342  * ib_req_notify_cq() in the generic verbs code.
 343  */
 344 int ipath_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
 345 {
 346         struct ipath_cq *cq = to_icq(ibcq);
 347         unsigned long flags;
 348         int ret = 0;
 349
 350         spin_lock_irqsave(&cq->lock, flags);
 351         /*
 352          * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow
 353          * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2).
 354          */
 355         if (cq->notify != IB_CQ_NEXT_COMP)
 356                 cq->notify = notify_flags & IB_CQ_SOLICITED_MASK;
 357
 358         if ((notify_flags & IB_CQ_REPORT_MISSED_EVENTS) &&
 359             cq->queue->head != cq->queue->tail)
 360                 ret = 1;
 361
 362         spin_unlock_irqrestore(&cq->lock, flags);
 363
 364         return ret;
 365 }
 366
 367 /**
 368  * ipath_resize_cq - change the size of the CQ
 369  * @ibcq: the completion queue
 370  *
 371  * Returns 0 for success.
 372  */
 373 int ipath_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
 374 {
 375         struct ipath_cq *cq = to_icq(ibcq);
 376         struct ipath_cq_wc *old_wc;
 377         struct ipath_cq_wc *wc;
 378         u32 head, tail, n;
 379         int ret;
 380
 381         if (cqe < 1 || cqe > ib_ipath_max_cqes) {
 382                 ret = -EINVAL;
 383                 goto bail;
 384         }
 385
 386         /*
 387          * Need to use vmalloc() if we want to support large #s of entries.
 388          */
 389         wc = vmalloc_user(sizeof(*wc) + sizeof(struct ib_wc) * cqe);
 390         if (!wc) {
 391                 ret = -ENOMEM;
 392                 goto bail;
 393         }
 394
 395         /*
 396          * Return the address of the WC as the offset to mmap.
 397          * See ipath_mmap() for details.
 398          */
 399         if (udata && udata->outlen >= sizeof(__u64)) {
 400                 __u64 offset = (__u64) wc;
 401
 402                 ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
 403                 if (ret)
 404                         goto bail;
 405         }
 406
 407         spin_lock_irq(&cq->lock);
 408         /*
 409          * Make sure head and tail are sane since they
 410          * might be user writable.
 411          */
 412         old_wc = cq->queue;
 413         head = old_wc->head;
 414         if (head > (u32) cq->ibcq.cqe)
 415                 head = (u32) cq->ibcq.cqe;
 416         tail = old_wc->tail;
 417         if (tail > (u32) cq->ibcq.cqe)
 418                 tail = (u32) cq->ibcq.cqe;
 419         if (head < tail)
 420                 n = cq->ibcq.cqe + 1 + head - tail;
 421         else
 422                 n = head - tail;
 423         if (unlikely((u32)cqe < n)) {
 424                 spin_unlock_irq(&cq->lock);
 425                 vfree(wc);
 426                 ret = -EOVERFLOW;
 427                 goto bail;
 428         }
 429         for (n = 0; tail != head; n++) {
 430                 wc->queue[n] = old_wc->queue[tail];
 431                 if (tail == (u32) cq->ibcq.cqe)
 432                         tail = 0;
 433                 else
 434                         tail++;
 435         }
 436         cq->ibcq.cqe = cqe;
 437         wc->head = n;
 438         wc->tail = 0;
 439         cq->queue = wc;
 440         spin_unlock_irq(&cq->lock);
 441
 442         vfree(old_wc);
 443
 444         if (cq->ip) {
 445                 struct ipath_ibdev *dev = to_idev(ibcq->device);
 446                 struct ipath_mmap_info *ip = cq->ip;
 447                 u32 s = sizeof *wc + sizeof(struct ib_wc) * cqe;
 448
 449                 ipath_update_mmap_info(dev, ip, s, wc);
 450                 spin_lock_irq(&dev->pending_lock);
 451                 if (list_empty(&ip->pending_mmaps))
 452                         list_add(&ip->pending_mmaps, &dev->pending_mmaps);
 453                 spin_unlock_irq(&dev->pending_lock);
 454         }
 455
 456         ret = 0;
 457
 458 bail:
 459         return ret;
 460 }