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 * $FreeBSD: stable/10/sys/dev/mlx5/mlx5_ib/mlx5_ib_doorbell.c 323223 2017-09-06 15:33:23Z hselasky $ 26 */ 27 28#include <linux/compiler.h> 29#include <linux/kref.h> 30#include <linux/slab.h> 31#include <rdma/ib_umem.h> 32 33#include "mlx5_ib.h" 34 35struct mlx5_ib_user_db_page { 36 struct list_head list; 37 struct ib_umem *umem; 38 uintptr_t user_virt; 39 int refcnt; 40}; 41 42int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, uintptr_t virt, 43 struct mlx5_db *db) 44{ 45 struct mlx5_ib_user_db_page *page; 46 struct ib_umem_chunk *chunk; 47 int err = 0; 48 49 mutex_lock(&context->db_page_mutex); 50 51 list_for_each_entry(page, &context->db_page_list, list) 52 if (page->user_virt == (virt & PAGE_MASK)) 53 goto found; 54 55 page = kmalloc(sizeof(*page), GFP_KERNEL); 56 if (!page) { 57 err = -ENOMEM; 58 goto out; 59 } 60 61 page->user_virt = (virt & PAGE_MASK); 62 page->refcnt = 0; 63 page->umem = ib_umem_get(&context->ibucontext, virt & PAGE_MASK, 64 PAGE_SIZE, 0, 0); 65 if (IS_ERR(page->umem)) { 66 err = PTR_ERR(page->umem); 67 kfree(page); 68 goto out; 69 } 70 71 list_add(&page->list, &context->db_page_list); 72 73found: 74 chunk = list_entry(page->umem->chunk_list.next, 75 struct ib_umem_chunk, list); 76 db->dma = sg_dma_address(chunk->page_list) + (virt & ~PAGE_MASK); 77 db->u.user_page = page; 78 ++page->refcnt; 79 80out: 81 mutex_unlock(&context->db_page_mutex); 82 83 return err; 84} 85 86void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db) 87{ 88 mutex_lock(&context->db_page_mutex); 89 90 if (!--db->u.user_page->refcnt) { 91 list_del(&db->u.user_page->list); 92 ib_umem_release(db->u.user_page->umem); 93 kfree(db->u.user_page); 94 } 95 96 mutex_unlock(&context->db_page_mutex); 97} 98