cregit-Linux how code gets into the kernel

Release 4.7 drivers/infiniband/sw/rdmavt/cq.c

/*
 * Copyright(c) 2016 Intel Corporation.
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/kthread.h>
#include "cq.h"
#include "vt.h"

/**
 * rvt_cq_enter - add a new entry to the completion queue
 * @cq: completion queue
 * @entry: work completion entry to add
 * @sig: true if @entry is solicited
 *
 * This may be called with qp->s_lock held.
 */

void rvt_cq_enter(struct rvt_cq *cq, struct ib_wc *entry, bool solicited) { struct rvt_cq_wc *wc; unsigned long flags; u32 head; u32 next; spin_lock_irqsave(&cq->lock, flags); /* * Note that the head pointer might be writable by user processes. * Take care to verify it is a sane value. */ wc = cq->queue; head = wc->head; if (head >= (unsigned)cq->ibcq.cqe) { head = cq->ibcq.cqe; next = 0; } else { next = head + 1; } if (unlikely(next == wc->tail)) { spin_unlock_irqrestore(&cq->lock, flags); if (cq->ibcq.event_handler) { struct ib_event ev; ev.device = cq->ibcq.device; ev.element.cq = &cq->ibcq; ev.event = IB_EVENT_CQ_ERR; cq->ibcq.event_handler(&ev, cq->ibcq.cq_context); } return; } if (cq->ip) { wc->uqueue[head].wr_id = entry->wr_id; wc->uqueue[head].status = entry->status; wc->uqueue[head].opcode = entry->opcode; wc->uqueue[head].vendor_err = entry->vendor_err; wc->uqueue[head].byte_len = entry->byte_len; wc->uqueue[head].ex.imm_data = (__u32 __force)entry->ex.imm_data; wc->uqueue[head].qp_num = entry->qp->qp_num; wc->uqueue[head].src_qp = entry->src_qp; wc->uqueue[head].wc_flags = entry->wc_flags; wc->uqueue[head].pkey_index = entry->pkey_index; wc->uqueue[head].slid = entry->slid; wc->uqueue[head].sl = entry->sl; wc->uqueue[head].dlid_path_bits = entry->dlid_path_bits; wc->uqueue[head].port_num = entry->port_num; /* Make sure entry is written before the head index. */ smp_wmb(); } else { wc->kqueue[head] = *entry; } wc->head = next; if (cq->notify == IB_CQ_NEXT_COMP || (cq->notify == IB_CQ_SOLICITED && (solicited || entry->status != IB_WC_SUCCESS))) { struct kthread_worker *worker; /* * This will cause send_complete() to be called in * another thread. */ smp_read_barrier_depends(); /* see rvt_cq_exit */ worker = cq->rdi->worker; if (likely(worker)) { cq->notify = RVT_CQ_NONE; cq->triggered++; queue_kthread_work(worker, &cq->comptask); } } spin_unlock_irqrestore(&cq->lock, flags); }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro482100.00%1100.00%
Total482100.00%1100.00%

EXPORT_SYMBOL(rvt_cq_enter);
static void send_complete(struct kthread_work *work) { struct rvt_cq *cq = container_of(work, struct rvt_cq, comptask); /* * The completion handler will most likely rearm the notification * and poll for all pending entries. If a new completion entry * is added while we are in this routine, queue_work() * won't call us again until we return so we check triggered to * see if we need to call the handler again. */ for (;;) { u8 triggered = cq->triggered; /* * IPoIB connected mode assumes the callback is from a * soft IRQ. We simulate this by blocking "bottom halves". * See the implementation for ipoib_cm_handle_tx_wc(), * netif_tx_lock_bh() and netif_tx_lock(). */ local_bh_disable(); cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context); local_bh_enable(); if (cq->triggered == triggered) return; } }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro75100.00%1100.00%
Total75100.00%1100.00%

/** * rvt_create_cq - create a completion queue * @ibdev: the device this completion queue is attached to * @attr: creation attributes * @context: unused by the QLogic_IB driver * @udata: user data for libibverbs.so * * Called by ib_create_cq() in the generic verbs code. * * Return: pointer to the completion queue or negative errno values * for failure. */
struct ib_cq *rvt_create_cq(struct ib_device *ibdev, const struct ib_cq_init_attr *attr, struct ib_ucontext *context, struct ib_udata *udata) { struct rvt_dev_info *rdi = ib_to_rvt(ibdev); struct rvt_cq *cq; struct rvt_cq_wc *wc; struct ib_cq *ret; u32 sz; unsigned int entries = attr->cqe; if (attr->flags) return ERR_PTR(-EINVAL); if (entries < 1 || entries > rdi->dparms.props.max_cqe) return ERR_PTR(-EINVAL); /* Allocate the completion queue structure. */ cq = kzalloc(sizeof(*cq), GFP_KERNEL); if (!cq) return ERR_PTR(-ENOMEM); /* * Allocate the completion queue entries and head/tail pointers. * This is allocated separately so that it can be resized and * also mapped into user space. * We need to use vmalloc() in order to support mmap and large * numbers of entries. */ sz = sizeof(*wc); if (udata && udata->outlen >= sizeof(__u64)) sz += sizeof(struct ib_uverbs_wc) * (entries + 1); else sz += sizeof(struct ib_wc) * (entries + 1); wc = vmalloc_user(sz); if (!wc) { ret = ERR_PTR(-ENOMEM); goto bail_cq; } /* * Return the address of the WC as the offset to mmap. * See rvt_mmap() for details. */ if (udata && udata->outlen >= sizeof(__u64)) { int err; cq->ip = rvt_create_mmap_info(rdi, sz, context, wc); if (!cq->ip) { ret = ERR_PTR(-ENOMEM); goto bail_wc; } err = ib_copy_to_udata(udata, &cq->ip->offset, sizeof(cq->ip->offset)); if (err) { ret = ERR_PTR(err); goto bail_ip; } } spin_lock(&rdi->n_cqs_lock); if (rdi->n_cqs_allocated == rdi->dparms.props.max_cq) { spin_unlock(&rdi->n_cqs_lock); ret = ERR_PTR(-ENOMEM); goto bail_ip; } rdi->n_cqs_allocated++; spin_unlock(&rdi->n_cqs_lock); if (cq->ip) { spin_lock_irq(&rdi->pending_lock); list_add(&cq->ip->pending_mmaps, &rdi->pending_mmaps); spin_unlock_irq(&rdi->pending_lock); } /* * ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe. * The number of entries should be >= the number requested or return * an error. */ cq->rdi = rdi; cq->ibcq.cqe = entries; cq->notify = RVT_CQ_NONE; spin_lock_init(&cq->lock); init_kthread_work(&cq->comptask, send_complete); cq->queue = wc; ret = &cq->ibcq; goto done; bail_ip: kfree(cq->ip); bail_wc: vfree(wc); bail_cq: kfree(cq); done: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro473100.00%2100.00%
Total473100.00%2100.00%

/** * rvt_destroy_cq - destroy a completion queue * @ibcq: the completion queue to destroy. * * Called by ib_destroy_cq() in the generic verbs code. * * Return: always 0 */
int rvt_destroy_cq(struct ib_cq *ibcq) { struct rvt_cq *cq = ibcq_to_rvtcq(ibcq); struct rvt_dev_info *rdi = cq->rdi; flush_kthread_work(&cq->comptask); spin_lock(&rdi->n_cqs_lock); rdi->n_cqs_allocated--; spin_unlock(&rdi->n_cqs_lock); if (cq->ip) kref_put(&cq->ip->ref, rvt_release_mmap_info); else vfree(cq->queue); kfree(cq); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro92100.00%2100.00%
Total92100.00%2100.00%

/** * rvt_req_notify_cq - change the notification type for a completion queue * @ibcq: the completion queue * @notify_flags: the type of notification to request * * This may be called from interrupt context. Also called by * ib_req_notify_cq() in the generic verbs code. * * Return: 0 for success. */
int rvt_req_notify_cq(struct ib_cq *ibcq, enum ib_cq_notify_flags notify_flags) { struct rvt_cq *cq = ibcq_to_rvtcq(ibcq); unsigned long flags; int ret = 0; spin_lock_irqsave(&cq->lock, flags); /* * Don't change IB_CQ_NEXT_COMP to IB_CQ_SOLICITED but allow * any other transitions (see C11-31 and C11-32 in ch. 11.4.2.2). */ if (cq->notify != IB_CQ_NEXT_COMP) cq->notify = notify_flags & IB_CQ_SOLICITED_MASK; if ((notify_flags & IB_CQ_REPORT_MISSED_EVENTS) && cq->queue->head != cq->queue->tail) ret = 1; spin_unlock_irqrestore(&cq->lock, flags); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro97100.00%2100.00%
Total97100.00%2100.00%

/** * rvt_resize_cq - change the size of the CQ * @ibcq: the completion queue * * Return: 0 for success. */
int rvt_resize_cq(struct ib_cq *ibcq, int cqe, struct ib_udata *udata) { struct rvt_cq *cq = ibcq_to_rvtcq(ibcq); struct rvt_cq_wc *old_wc; struct rvt_cq_wc *wc; u32 head, tail, n; int ret; u32 sz; struct rvt_dev_info *rdi = cq->rdi; if (cqe < 1 || cqe > rdi->dparms.props.max_cqe) return -EINVAL; /* * Need to use vmalloc() if we want to support large #s of entries. */ sz = sizeof(*wc); if (udata && udata->outlen >= sizeof(__u64)) sz += sizeof(struct ib_uverbs_wc) * (cqe + 1); else sz += sizeof(struct ib_wc) * (cqe + 1); wc = vmalloc_user(sz); if (!wc) return -ENOMEM; /* Check that we can write the offset to mmap. */ if (udata && udata->outlen >= sizeof(__u64)) { __u64 offset = 0; ret = ib_copy_to_udata(udata, &offset, sizeof(offset)); if (ret) goto bail_free; } spin_lock_irq(&cq->lock); /* * Make sure head and tail are sane since they * might be user writable. */ old_wc = cq->queue; head = old_wc->head; if (head > (u32)cq->ibcq.cqe) head = (u32)cq->ibcq.cqe; tail = old_wc->tail; if (tail > (u32)cq->ibcq.cqe) tail = (u32)cq->ibcq.cqe; if (head < tail) n = cq->ibcq.cqe + 1 + head - tail; else n = head - tail; if (unlikely((u32)cqe < n)) { ret = -EINVAL; goto bail_unlock; } for (n = 0; tail != head; n++) { if (cq->ip) wc->uqueue[n] = old_wc->uqueue[tail]; else wc->kqueue[n] = old_wc->kqueue[tail]; if (tail == (u32)cq->ibcq.cqe) tail = 0; else tail++; } cq->ibcq.cqe = cqe; wc->head = n; wc->tail = 0; cq->queue = wc; spin_unlock_irq(&cq->lock); vfree(old_wc); if (cq->ip) { struct rvt_mmap_info *ip = cq->ip; rvt_update_mmap_info(rdi, ip, sz, wc); /* * Return the offset to mmap. * See rvt_mmap() for details. */ if (udata && udata->outlen >= sizeof(__u64)) { ret = ib_copy_to_udata(udata, &ip->offset, sizeof(ip->offset)); if (ret) return ret; } spin_lock_irq(&rdi->pending_lock); if (list_empty(&ip->pending_mmaps)) list_add(&ip->pending_mmaps, &rdi->pending_mmaps); spin_unlock_irq(&rdi->pending_lock); } return 0; bail_unlock: spin_unlock_irq(&cq->lock); bail_free: vfree(wc); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro556100.00%3100.00%
Total556100.00%3100.00%

/** * rvt_poll_cq - poll for work completion entries * @ibcq: the completion queue to poll * @num_entries: the maximum number of entries to return * @entry: pointer to array where work completions are placed * * This may be called from interrupt context. Also called by ib_poll_cq() * in the generic verbs code. * * Return: the number of completion entries polled. */
int rvt_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry) { struct rvt_cq *cq = ibcq_to_rvtcq(ibcq); struct rvt_cq_wc *wc; unsigned long flags; int npolled; u32 tail; /* The kernel can only poll a kernel completion queue */ if (cq->ip) return -EINVAL; spin_lock_irqsave(&cq->lock, flags); wc = cq->queue; tail = wc->tail; if (tail > (u32)cq->ibcq.cqe) tail = (u32)cq->ibcq.cqe; for (npolled = 0; npolled < num_entries; ++npolled, ++entry) { if (tail == wc->head) break; /* The kernel doesn't need a RMB since it has the lock. */ *entry = wc->kqueue[tail]; if (tail >= cq->ibcq.cqe) tail = 0; else tail++; } wc->tail = tail; spin_unlock_irqrestore(&cq->lock, flags); return npolled; }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro175100.00%2100.00%
Total175100.00%2100.00%

/** * rvt_driver_cq_init - Init cq resources on behalf of driver * @rdi: rvt dev structure * * Return: 0 on success */
int rvt_driver_cq_init(struct rvt_dev_info *rdi) { int ret = 0; int cpu; struct task_struct *task; if (rdi->worker) return 0; rdi->worker = kzalloc(sizeof(*rdi->worker), GFP_KERNEL); if (!rdi->worker) return -ENOMEM; init_kthread_worker(rdi->worker); task = kthread_create_on_node( kthread_worker_fn, rdi->worker, rdi->dparms.node, "%s", rdi->dparms.cq_name); if (IS_ERR(task)) { kfree(rdi->worker); rdi->worker = NULL; return PTR_ERR(task); } set_user_nice(task, MIN_NICE); cpu = cpumask_first(cpumask_of_node(rdi->dparms.node)); kthread_bind(task, cpu); wake_up_process(task); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro14995.51%150.00%
mike marciniszynmike marciniszyn74.49%150.00%
Total156100.00%2100.00%

/** * rvt_cq_exit - tear down cq reources * @rdi: rvt dev structure */
void rvt_cq_exit(struct rvt_dev_info *rdi) { struct kthread_worker *worker; worker = rdi->worker; if (!worker) return; /* blocks future queuing from send_complete() */ rdi->worker = NULL; smp_wmb(); /* See rdi_cq_enter */ flush_kthread_worker(worker); kthread_stop(worker->task); kfree(worker); }

Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro55100.00%2100.00%
Total55100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
dennis dalessandrodennis dalessandro218399.68%583.33%
mike marciniszynmike marciniszyn70.32%116.67%
Total2190100.00%6100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}