/* * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the * OpenIB.org BSD license below: * * 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. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include <linux/kref.h> #include <linux/slab.h> #include <rdma/ib_umem.h> #include "mlx5_ib.h" struct mlx5_ib_user_db_page { struct list_head list; struct ib_umem *umem; unsigned long user_virt; int refcnt; }; int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt, struct mlx5_db *db) { struct mlx5_ib_user_db_page *page; int err = 0; mutex_lock(&context->db_page_mutex); list_for_each_entry(page, &context->db_page_list, list) if (page->user_virt == (virt & PAGE_MASK)) goto found; page = kmalloc(sizeof(*page), GFP_KERNEL); if (!page) { err = -ENOMEM; goto out; } page->user_virt = (virt & PAGE_MASK); page->refcnt = 0; page->umem = ib_umem_get(&context->ibucontext, virt & PAGE_MASK, PAGE_SIZE, 0, 0); if (IS_ERR(page->umem)) { err = PTR_ERR(page->umem); kfree(page); goto out; } list_add(&page->list, &context->db_page_list); found: db->dma = sg_dma_address(page->umem->sg_head.sgl) + (virt & ~PAGE_MASK); db->u.user_page = page; ++page->refcnt; out: mutex_unlock(&context->db_page_mutex); return err; } void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db) { mutex_lock(&context->db_page_mutex); if (!--db->u.user_page->refcnt) { list_del(&db->u.user_page->list); ib_umem_release(db->u.user_page->umem); kfree(db->u.user_page); } mutex_unlock(&context->db_page_mutex); }