1 /*- 2 * Copyright (c) 2013-2015, Mellanox Technologies, Ltd. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS `AS IS' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include "opt_rss.h" 27 #include "opt_ratelimit.h" 28 29 #include <linux/kref.h> 30 #include <linux/slab.h> 31 #include <rdma/ib_umem.h> 32 33 #include <dev/mlx5/mlx5_ib/mlx5_ib.h> 34 35 struct mlx5_ib_user_db_page { 36 struct list_head list; 37 struct ib_umem *umem; 38 unsigned long user_virt; 39 int refcnt; 40 }; 41 42 int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt, 43 struct mlx5_db *db) 44 { 45 struct mlx5_ib_user_db_page *page; 46 int err = 0; 47 48 mutex_lock(&context->db_page_mutex); 49 50 list_for_each_entry(page, &context->db_page_list, list) 51 if (page->user_virt == (virt & PAGE_MASK)) 52 goto found; 53 54 page = kmalloc(sizeof(*page), GFP_KERNEL); 55 if (!page) { 56 err = -ENOMEM; 57 goto out; 58 } 59 60 page->user_virt = (virt & PAGE_MASK); 61 page->refcnt = 0; 62 page->umem = ib_umem_get(&context->ibucontext, virt & PAGE_MASK, 63 PAGE_SIZE, 0, 0); 64 if (IS_ERR(page->umem)) { 65 err = PTR_ERR(page->umem); 66 kfree(page); 67 goto out; 68 } 69 70 list_add(&page->list, &context->db_page_list); 71 72 found: 73 db->dma = sg_dma_address(page->umem->sg_head.sgl) + (virt & ~PAGE_MASK); 74 db->u.user_page = page; 75 ++page->refcnt; 76 77 out: 78 mutex_unlock(&context->db_page_mutex); 79 80 return err; 81 } 82 83 void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db) 84 { 85 mutex_lock(&context->db_page_mutex); 86 87 if (!--db->u.user_page->refcnt) { 88 list_del(&db->u.user_page->list); 89 ib_umem_release(db->u.user_page->umem); 90 kfree(db->u.user_page); 91 } 92 93 mutex_unlock(&context->db_page_mutex); 94 } 95