1/*- 2 * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0 3 * 4 * Copyright (c) 2017 Mellanox Technologies Ltd. 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 <sys/cdefs.h> 36#include <linux/module.h> 37#include <linux/err.h> 38#include <linux/slab.h> 39 40#include <rdma/ib_verbs.h> 41 42#define IB_CQ_POLL_MAX 16 43/* maximum number of completions per poll loop */ 44#define IB_CQ_POLL_BUDGET 65536 45#define IB_CQ_POLL_FLAGS (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS) 46 47static void 48ib_cq_poll_work(struct work_struct *work) 49{ 50 struct ib_wc ib_wc[IB_CQ_POLL_MAX]; 51 struct ib_cq *cq = container_of(work, struct ib_cq, work); 52 int total = 0; 53 int i; 54 int n; 55 56 while (1) { 57 n = ib_poll_cq(cq, IB_CQ_POLL_MAX, ib_wc); 58 for (i = 0; i < n; i++) { 59 struct ib_wc *wc = ib_wc + i; 60 61 if (wc->wr_cqe != NULL) 62 wc->wr_cqe->done(cq, wc); 63 } 64 65 if (n != IB_CQ_POLL_MAX) { 66 if (ib_req_notify_cq(cq, IB_CQ_POLL_FLAGS) > 0) 67 break; 68 else 69 return; 70 } 71 total += n; 72 if (total >= IB_CQ_POLL_BUDGET) 73 break; 74 } 75 76 /* give other work structs a chance */ 77 queue_work(ib_comp_wq, &cq->work); 78} 79 80static void 81ib_cq_completion_workqueue(struct ib_cq *cq, void *private) 82{ 83 queue_work(ib_comp_wq, &cq->work); 84} 85 86struct ib_cq * 87__ib_alloc_cq_user(struct ib_device *dev, void *private, 88 int nr_cqe, int comp_vector, 89 enum ib_poll_context poll_ctx, 90 const char *caller, struct ib_udata *udata) 91{ 92 struct ib_cq_init_attr cq_attr = { 93 .cqe = nr_cqe, 94 .comp_vector = comp_vector, 95 }; 96 struct ib_cq *cq; 97 int ret; 98 99 /* 100 * Check for invalid parameters early on to avoid 101 * extra error handling code: 102 */ 103 switch (poll_ctx) { 104 case IB_POLL_DIRECT: 105 case IB_POLL_SOFTIRQ: 106 case IB_POLL_WORKQUEUE: 107 break; 108 default: 109 return (ERR_PTR(-EINVAL)); 110 } 111 112 cq = rdma_zalloc_drv_obj(dev, ib_cq); 113 if (!cq) 114 return ERR_PTR(-ENOMEM); 115 116 cq->device = dev; 117 cq->cq_context = private; 118 cq->poll_ctx = poll_ctx; 119 atomic_set(&cq->usecnt, 0); 120 121 ret = dev->create_cq(cq, &cq_attr, NULL); 122 if (ret) 123 goto out_free_cq; 124 125 switch (poll_ctx) { 126 case IB_POLL_DIRECT: 127 cq->comp_handler = NULL; /* no hardware completions */ 128 break; 129 case IB_POLL_SOFTIRQ: 130 case IB_POLL_WORKQUEUE: 131 cq->comp_handler = ib_cq_completion_workqueue; 132 INIT_WORK(&cq->work, ib_cq_poll_work); 133 ib_req_notify_cq(cq, IB_CQ_NEXT_COMP); 134 break; 135 default: 136 break; 137 } 138 return (cq); 139 140out_free_cq: 141 kfree(cq); 142 return (ERR_PTR(ret)); 143} 144EXPORT_SYMBOL(__ib_alloc_cq_user); 145 146void 147ib_free_cq_user(struct ib_cq *cq, struct ib_udata *udata) 148{ 149 150 if (WARN_ON_ONCE(atomic_read(&cq->usecnt) != 0)) 151 return; 152 153 switch (cq->poll_ctx) { 154 case IB_POLL_DIRECT: 155 break; 156 case IB_POLL_SOFTIRQ: 157 case IB_POLL_WORKQUEUE: 158 flush_work(&cq->work); 159 break; 160 default: 161 break; 162 } 163 164 cq->device->destroy_cq(cq, udata); 165 kfree(cq); 166} 167EXPORT_SYMBOL(ib_free_cq_user); 168