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1/*2 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.3 *4 * This software is available to you under a choice of one of two5 * licenses. You may choose to be licensed under the terms of the GNU6 * General Public License (GPL) Version 2, available from the file7 * COPYING in the main directory of this source tree, or the8 * OpenIB.org BSD license below:9 *10 * Redistribution and use in source and binary forms, with or11 * without modification, are permitted provided that the following12 * conditions are met:13 *14 * - Redistributions of source code must retain the above15 * copyright notice, this list of conditions and the following16 * disclaimer.17 *18 * - Redistributions in binary form must reproduce the above19 * copyright notice, this list of conditions and the following20 * disclaimer in the documentation and/or other materials21 * provided with the distribution.22 *23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE30 * SOFTWARE.31 */32 33#include <linux/slab.h>34#include <rdma/uverbs_ioctl.h>35 36#include "mlx4_ib.h"37 38struct mlx4_ib_user_db_page {39 struct list_head list;40 struct ib_umem *umem;41 unsigned long user_virt;42 int refcnt;43};44 45int mlx4_ib_db_map_user(struct ib_udata *udata, unsigned long virt,46 struct mlx4_db *db)47{48 struct mlx4_ib_user_db_page *page;49 int err = 0;50 struct mlx4_ib_ucontext *context = rdma_udata_to_drv_context(51 udata, struct mlx4_ib_ucontext, ibucontext);52 53 mutex_lock(&context->db_page_mutex);54 55 list_for_each_entry(page, &context->db_page_list, list)56 if (page->user_virt == (virt & PAGE_MASK))57 goto found;58 59 page = kmalloc(sizeof *page, GFP_KERNEL);60 if (!page) {61 err = -ENOMEM;62 goto out;63 }64 65 page->user_virt = (virt & PAGE_MASK);66 page->refcnt = 0;67 page->umem = ib_umem_get(context->ibucontext.device, virt & PAGE_MASK,68 PAGE_SIZE, 0);69 if (IS_ERR(page->umem)) {70 err = PTR_ERR(page->umem);71 kfree(page);72 goto out;73 }74 75 list_add(&page->list, &context->db_page_list);76 77found:78 db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) +79 (virt & ~PAGE_MASK);80 db->u.user_page = page;81 ++page->refcnt;82 83out:84 mutex_unlock(&context->db_page_mutex);85 86 return err;87}88 89void mlx4_ib_db_unmap_user(struct mlx4_ib_ucontext *context, struct mlx4_db *db)90{91 mutex_lock(&context->db_page_mutex);92 93 if (!--db->u.user_page->refcnt) {94 list_del(&db->u.user_page->list);95 ib_umem_release(db->u.user_page->umem);96 kfree(db->u.user_page);97 }98 99 mutex_unlock(&context->db_page_mutex);100}101