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