linux/drivers/infiniband/sw/rdmavt/cq.c
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   1/*
   2 * Copyright(c) 2016 - 2018 Intel Corporation.
   3 *
   4 * This file is provided under a dual BSD/GPLv2 license.  When using or
   5 * redistributing this file, you may do so under either license.
   6 *
   7 * GPL LICENSE SUMMARY
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of version 2 of the GNU General Public License as
  11 * published by the Free Software Foundation.
  12 *
  13 * This program is distributed in the hope that it will be useful, but
  14 * WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 * General Public License for more details.
  17 *
  18 * BSD LICENSE
  19 *
  20 * Redistribution and use in source and binary forms, with or without
  21 * modification, are permitted provided that the following conditions
  22 * are met:
  23 *
  24 *  - Redistributions of source code must retain the above copyright
  25 *    notice, this list of conditions and the following disclaimer.
  26 *  - Redistributions in binary form must reproduce the above copyright
  27 *    notice, this list of conditions and the following disclaimer in
  28 *    the documentation and/or other materials provided with the
  29 *    distribution.
  30 *  - Neither the name of Intel Corporation nor the names of its
  31 *    contributors may be used to endorse or promote products derived
  32 *    from this software without specific prior written permission.
  33 *
  34 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45 *
  46 */
  47
  48#include <linux/slab.h>
  49#include <linux/vmalloc.h>
  50#include "cq.h"
  51#include "vt.h"
  52#include "trace.h"
  53
  54static struct workqueue_struct *comp_vector_wq;
  55
  56/**
  57 * rvt_cq_enter - add a new entry to the completion queue
  58 * @cq: completion queue
  59 * @entry: work completion entry to add
  60 * @solicited: true if @entry is solicited
  61 *
  62 * This may be called with qp->s_lock held.
  63 *
  64 * Return: return true on success, else return
  65 * false if cq is full.
  66 */
  67bool rvt_cq_enter(struct rvt_cq *cq, struct ib_wc *entry, bool solicited)
  68{
  69        struct ib_uverbs_wc *uqueue = NULL;
  70        struct ib_wc *kqueue = NULL;
  71        struct rvt_cq_wc *u_wc = NULL;
  72        struct rvt_k_cq_wc *k_wc = NULL;
  73        unsigned long flags;
  74        u32 head;
  75        u32 next;
  76        u32 tail;
  77
  78        spin_lock_irqsave(&cq->lock, flags);
  79
  80        if (cq->ip) {
  81                u_wc = cq->queue;
  82                uqueue = &u_wc->uqueue[0];
  83                head = RDMA_READ_UAPI_ATOMIC(u_wc->head);
  84                tail = RDMA_READ_UAPI_ATOMIC(u_wc->tail);
  85        } else {
  86                k_wc = cq->kqueue;
  87                kqueue = &k_wc->kqueue[0];
  88                head = k_wc->head;
  89                tail = k_wc->tail;
  90        }
  91
  92        /*
  93         * Note that the head pointer might be writable by
  94         * user processes.Take care to verify it is a sane value.
  95         */
  96        if (head >= (unsigned)cq->ibcq.cqe) {
  97                head = cq->ibcq.cqe;
  98                next = 0;
  99        } else {
 100                next = head + 1;
 101        }
 102
 103        if (unlikely(next == tail || cq->cq_full)) {
 104                struct rvt_dev_info *rdi = cq->rdi;
 105
 106                if (!cq->cq_full)
 107                        rvt_pr_err_ratelimited(rdi, "CQ is full!\n");
 108                cq->cq_full = true;
 109                spin_unlock_irqrestore(&cq->lock, flags);
 110                if (cq->ibcq.event_handler) {
 111                        struct ib_event ev;
 112
 113                        ev.device = cq->ibcq.device;
 114                        ev.element.cq = &cq->ibcq;
 115                        ev.event = IB_EVENT_CQ_ERR;
 116                        cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
 117                }
 118                return false;
 119        }
 120        trace_rvt_cq_enter(cq, entry, head);
 121        if (uqueue) {
 122                uqueue[head].wr_id = entry->wr_id;
 123                uqueue[head].status = entry->status;
 124                uqueue[head].opcode = entry->opcode;
 125                uqueue[head].vendor_err = entry->vendor_err;
 126                uqueue[head].byte_len = entry->byte_len;
 127                uqueue[head].ex.imm_data = entry->ex.imm_data;
 128                uqueue[head].qp_num = entry->qp->qp_num;
 129                uqueue[head].src_qp = entry->src_qp;
 130                uqueue[head].wc_flags = entry->wc_flags;
 131                uqueue[head].pkey_index = entry->pkey_index;
 132                uqueue[head].slid = ib_lid_cpu16(entry->slid);
 133                uqueue[head].sl = entry->sl;
 134                uqueue[head].dlid_path_bits = entry->dlid_path_bits;
 135                uqueue[head].port_num = entry->port_num;
 136                /* Make sure entry is written before the head index. */
 137                RDMA_WRITE_UAPI_ATOMIC(u_wc->head, next);
 138        } else {
 139                kqueue[head] = *entry;
 140                k_wc->head = next;
 141        }
 142
 143        if (cq->notify == IB_CQ_NEXT_COMP ||
 144            (cq->notify == IB_CQ_SOLICITED &&
 145             (solicited || entry->status != IB_WC_SUCCESS))) {
 146                /*
 147                 * This will cause send_complete() to be called in
 148                 * another thread.
 149                 */
 150                cq->notify = RVT_CQ_NONE;
 151                cq->triggered++;
 152                queue_work_on(cq->comp_vector_cpu, comp_vector_wq,
 153                              &cq->comptask);
 154        }
 155
 156        spin_unlock_irqrestore(&cq->lock, flags);
 157        return true;
 158}
 159EXPORT_SYMBOL(rvt_cq_enter);
 160
 161static void send_complete(struct work_struct *work)
 162{
 163        struct rvt_cq *cq = container_of(work, struct rvt_cq, comptask);
 164
 165        /*
 166         * The completion handler will most likely rearm the notification
 167         * and poll for all pending entries.  If a new completion entry
 168         * is added while we are in this routine, queue_work()
 169         * won't call us again until we return so we check triggered to
 170         * see if we need to call the handler again.
 171         */
 172        for (;;) {
 173                u8 triggered = cq->triggered;
 174
 175                /*
 176                 * IPoIB connected mode assumes the callback is from a
 177                 * soft IRQ. We simulate this by blocking "bottom halves".
 178                 * See the implementation for ipoib_cm_handle_tx_wc(),
 179                 * netif_tx_lock_bh() and netif_tx_lock().
 180                 */
 181                local_bh_disable();
 182                cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
 183                local_bh_enable();
 184
 185                if (cq->triggered == triggered)
 186                        return;
 187        }
 188}
 189
 190/**
 191 * rvt_create_cq - create a completion queue
 192 * @ibcq: Allocated CQ
 193 * @attr: creation attributes
 194 * @udata: user data for libibverbs.so
 195 *
 196 * Called by ib_create_cq() in the generic verbs code.
 197 *
 198 * Return: 0 on success
 199 */
 200int rvt_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
 201                  struct ib_udata *udata)
 202{
 203        struct ib_device *ibdev = ibcq->device;
 204        struct rvt_dev_info *rdi = ib_to_rvt(ibdev);
 205        struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
 206        struct rvt_cq_wc *u_wc = NULL;
 207        struct rvt_k_cq_wc *k_wc = NULL;
 208        u32 sz;
 209        unsigned int entries = attr->cqe;
 210        int comp_vector = attr->comp_vector;
 211        int err;
 212
 213        if (attr->flags)
 214                return -EINVAL;
 215
 216        if (entries < 1 || entries > rdi->dparms.props.max_cqe)
 217                return -EINVAL;
 218
 219        if (comp_vector < 0)
 220                comp_vector = 0;
 221
 222        comp_vector = comp_vector % rdi->ibdev.num_comp_vectors;
 223
 224        /*
 225         * Allocate the completion queue entries and head/tail pointers.
 226         * This is allocated separately so that it can be resized and
 227         * also mapped into user space.
 228         * We need to use vmalloc() in order to support mmap and large
 229         * numbers of entries.
 230         */
 231        if (udata && udata->outlen >= sizeof(__u64)) {
 232                sz = sizeof(struct ib_uverbs_wc) * (entries + 1);
 233                sz += sizeof(*u_wc);
 234                u_wc = vmalloc_user(sz);
 235                if (!u_wc)
 236                        return -ENOMEM;
 237        } else {
 238                sz = sizeof(struct ib_wc) * (entries + 1);
 239                sz += sizeof(*k_wc);
 240                k_wc = vzalloc_node(sz, rdi->dparms.node);
 241                if (!k_wc)
 242                        return -ENOMEM;
 243        }
 244
 245        /*
 246         * Return the address of the WC as the offset to mmap.
 247         * See rvt_mmap() for details.
 248         */
 249        if (udata && udata->outlen >= sizeof(__u64)) {
 250                cq->ip = rvt_create_mmap_info(rdi, sz, udata, u_wc);
 251                if (IS_ERR(cq->ip)) {
 252                        err = PTR_ERR(cq->ip);
 253                        goto bail_wc;
 254                }
 255
 256                err = ib_copy_to_udata(udata, &cq->ip->offset,
 257                                       sizeof(cq->ip->offset));
 258                if (err)
 259                        goto bail_ip;
 260        }
 261
 262        spin_lock_irq(&rdi->n_cqs_lock);
 263        if (rdi->n_cqs_allocated == rdi->dparms.props.max_cq) {
 264                spin_unlock_irq(&rdi->n_cqs_lock);
 265                err = -ENOMEM;
 266                goto bail_ip;
 267        }
 268
 269        rdi->n_cqs_allocated++;
 270        spin_unlock_irq(&rdi->n_cqs_lock);
 271
 272        if (cq->ip) {
 273                spin_lock_irq(&rdi->pending_lock);
 274                list_add(&cq->ip->pending_mmaps, &rdi->pending_mmaps);
 275                spin_unlock_irq(&rdi->pending_lock);
 276        }
 277
 278        /*
 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.
 282         */
 283        cq->rdi = rdi;
 284        if (rdi->driver_f.comp_vect_cpu_lookup)
 285                cq->comp_vector_cpu =
 286                        rdi->driver_f.comp_vect_cpu_lookup(rdi, comp_vector);
 287        else
 288                cq->comp_vector_cpu =
 289                        cpumask_first(cpumask_of_node(rdi->dparms.node));
 290
 291        cq->ibcq.cqe = entries;
 292        cq->notify = RVT_CQ_NONE;
 293        spin_lock_init(&cq->lock);
 294        INIT_WORK(&cq->comptask, send_complete);
 295        if (u_wc)
 296                cq->queue = u_wc;
 297        else
 298                cq->kqueue = k_wc;
 299
 300        trace_rvt_create_cq(cq, attr);
 301        return 0;
 302
 303bail_ip:
 304        kfree(cq->ip);
 305bail_wc:
 306        vfree(u_wc);
 307        vfree(k_wc);
 308        return err;
 309}
 310
 311/**
 312 * rvt_destroy_cq - destroy a completion queue
 313 * @ibcq: the completion queue to destroy.
 314 * @udata: user data or NULL for kernel object
 315 *
 316 * Called by ib_destroy_cq() in the generic verbs code.
 317 */
 318int rvt_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata)
 319{
 320        struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
 321        struct rvt_dev_info *rdi = cq->rdi;
 322
 323        flush_work(&cq->comptask);
 324        spin_lock_irq(&rdi->n_cqs_lock);
 325        rdi->n_cqs_allocated--;
 326        spin_unlock_irq(&rdi->n_cqs_lock);
 327        if (cq->ip)
 328                kref_put(&cq->ip->ref, rvt_release_mmap_info);
 329        else
 330                vfree(cq->kqueue);
 331        return 0;
 332}
 333
 334/**
 335 * rvt_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 * This may be called from interrupt context.  Also called by
 340 * ib_req_notify_cq() in the generic verbs code.
 341 *
 342 * Return: 0 for success.
 343 */
 344int rvt_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags)
 345{
 346        struct rvt_cq *cq = ibcq_to_rvtcq(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                if (cq->queue) {
 360                        if (RDMA_READ_UAPI_ATOMIC(cq->queue->head) !=
 361                                RDMA_READ_UAPI_ATOMIC(cq->queue->tail))
 362                                ret = 1;
 363                } else {
 364                        if (cq->kqueue->head != cq->kqueue->tail)
 365                                ret = 1;
 366                }
 367        }
 368
 369        spin_unlock_irqrestore(&cq->lock, flags);
 370
 371        return ret;
 372}
 373
 374/**
 375 * rvt_resize_cq - change the size of the CQ
 376 * @ibcq: the completion queue
 377 *
 378 * Return: 0 for success.
 379 */
 380int rvt_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata)
 381{
 382        struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
 383        u32 head, tail, n;
 384        int ret;
 385        u32 sz;
 386        struct rvt_dev_info *rdi = cq->rdi;
 387        struct rvt_cq_wc *u_wc = NULL;
 388        struct rvt_cq_wc *old_u_wc = NULL;
 389        struct rvt_k_cq_wc *k_wc = NULL;
 390        struct rvt_k_cq_wc *old_k_wc = NULL;
 391
 392        if (cqe < 1 || cqe > rdi->dparms.props.max_cqe)
 393                return -EINVAL;
 394
 395        /*
 396         * Need to use vmalloc() if we want to support large #s of entries.
 397         */
 398        if (udata && udata->outlen >= sizeof(__u64)) {
 399                sz = sizeof(struct ib_uverbs_wc) * (cqe + 1);
 400                sz += sizeof(*u_wc);
 401                u_wc = vmalloc_user(sz);
 402                if (!u_wc)
 403                        return -ENOMEM;
 404        } else {
 405                sz = sizeof(struct ib_wc) * (cqe + 1);
 406                sz += sizeof(*k_wc);
 407                k_wc = vzalloc_node(sz, rdi->dparms.node);
 408                if (!k_wc)
 409                        return -ENOMEM;
 410        }
 411        /* Check that we can write the offset to mmap. */
 412        if (udata && udata->outlen >= sizeof(__u64)) {
 413                __u64 offset = 0;
 414
 415                ret = ib_copy_to_udata(udata, &offset, sizeof(offset));
 416                if (ret)
 417                        goto bail_free;
 418        }
 419
 420        spin_lock_irq(&cq->lock);
 421        /*
 422         * Make sure head and tail are sane since they
 423         * might be user writable.
 424         */
 425        if (u_wc) {
 426                old_u_wc = cq->queue;
 427                head = RDMA_READ_UAPI_ATOMIC(old_u_wc->head);
 428                tail = RDMA_READ_UAPI_ATOMIC(old_u_wc->tail);
 429        } else {
 430                old_k_wc = cq->kqueue;
 431                head = old_k_wc->head;
 432                tail = old_k_wc->tail;
 433        }
 434
 435        if (head > (u32)cq->ibcq.cqe)
 436                head = (u32)cq->ibcq.cqe;
 437        if (tail > (u32)cq->ibcq.cqe)
 438                tail = (u32)cq->ibcq.cqe;
 439        if (head < tail)
 440                n = cq->ibcq.cqe + 1 + head - tail;
 441        else
 442                n = head - tail;
 443        if (unlikely((u32)cqe < n)) {
 444                ret = -EINVAL;
 445                goto bail_unlock;
 446        }
 447        for (n = 0; tail != head; n++) {
 448                if (u_wc)
 449                        u_wc->uqueue[n] = old_u_wc->uqueue[tail];
 450                else
 451                        k_wc->kqueue[n] = old_k_wc->kqueue[tail];
 452                if (tail == (u32)cq->ibcq.cqe)
 453                        tail = 0;
 454                else
 455                        tail++;
 456        }
 457        cq->ibcq.cqe = cqe;
 458        if (u_wc) {
 459                RDMA_WRITE_UAPI_ATOMIC(u_wc->head, n);
 460                RDMA_WRITE_UAPI_ATOMIC(u_wc->tail, 0);
 461                cq->queue = u_wc;
 462        } else {
 463                k_wc->head = n;
 464                k_wc->tail = 0;
 465                cq->kqueue = k_wc;
 466        }
 467        spin_unlock_irq(&cq->lock);
 468
 469        if (u_wc)
 470                vfree(old_u_wc);
 471        else
 472                vfree(old_k_wc);
 473
 474        if (cq->ip) {
 475                struct rvt_mmap_info *ip = cq->ip;
 476
 477                rvt_update_mmap_info(rdi, ip, sz, u_wc);
 478
 479                /*
 480                 * Return the offset to mmap.
 481                 * See rvt_mmap() for details.
 482                 */
 483                if (udata && udata->outlen >= sizeof(__u64)) {
 484                        ret = ib_copy_to_udata(udata, &ip->offset,
 485                                               sizeof(ip->offset));
 486                        if (ret)
 487                                return ret;
 488                }
 489
 490                spin_lock_irq(&rdi->pending_lock);
 491                if (list_empty(&ip->pending_mmaps))
 492                        list_add(&ip->pending_mmaps, &rdi->pending_mmaps);
 493                spin_unlock_irq(&rdi->pending_lock);
 494        }
 495
 496        return 0;
 497
 498bail_unlock:
 499        spin_unlock_irq(&cq->lock);
 500bail_free:
 501        vfree(u_wc);
 502        vfree(k_wc);
 503
 504        return ret;
 505}
 506
 507/**
 508 * rvt_poll_cq - poll for work completion entries
 509 * @ibcq: the completion queue to poll
 510 * @num_entries: the maximum number of entries to return
 511 * @entry: pointer to array where work completions are placed
 512 *
 513 * This may be called from interrupt context.  Also called by ib_poll_cq()
 514 * in the generic verbs code.
 515 *
 516 * Return: the number of completion entries polled.
 517 */
 518int rvt_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
 519{
 520        struct rvt_cq *cq = ibcq_to_rvtcq(ibcq);
 521        struct rvt_k_cq_wc *wc;
 522        unsigned long flags;
 523        int npolled;
 524        u32 tail;
 525
 526        /* The kernel can only poll a kernel completion queue */
 527        if (cq->ip)
 528                return -EINVAL;
 529
 530        spin_lock_irqsave(&cq->lock, flags);
 531
 532        wc = cq->kqueue;
 533        tail = wc->tail;
 534        if (tail > (u32)cq->ibcq.cqe)
 535                tail = (u32)cq->ibcq.cqe;
 536        for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
 537                if (tail == wc->head)
 538                        break;
 539                /* The kernel doesn't need a RMB since it has the lock. */
 540                trace_rvt_cq_poll(cq, &wc->kqueue[tail], npolled);
 541                *entry = wc->kqueue[tail];
 542                if (tail >= cq->ibcq.cqe)
 543                        tail = 0;
 544                else
 545                        tail++;
 546        }
 547        wc->tail = tail;
 548
 549        spin_unlock_irqrestore(&cq->lock, flags);
 550
 551        return npolled;
 552}
 553
 554/**
 555 * rvt_driver_cq_init - Init cq resources on behalf of driver
 556 *
 557 * Return: 0 on success
 558 */
 559int rvt_driver_cq_init(void)
 560{
 561        comp_vector_wq = alloc_workqueue("%s", WQ_HIGHPRI | WQ_CPU_INTENSIVE,
 562                                         0, "rdmavt_cq");
 563        if (!comp_vector_wq)
 564                return -ENOMEM;
 565
 566        return 0;
 567}
 568
 569/**
 570 * rvt_cq_exit - tear down cq reources
 571 */
 572void rvt_cq_exit(void)
 573{
 574        destroy_workqueue(comp_vector_wq);
 575        comp_vector_wq = NULL;
 576}
 577