cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

doorbell.c (2933B)

      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 two
      5 * licenses.  You may choose to be licensed under the terms of the GNU
      6 * General Public License (GPL) Version 2, available from the file
      7 * COPYING in the main directory of this source tree, or the
      8 * OpenIB.org BSD license below:
      9 *
     10 *     Redistribution and use in source and binary forms, with or
     11 *     without modification, are permitted provided that the following
     12 *     conditions are met:
     13 *
     14 *      - Redistributions of source code must retain the above
     15 *        copyright notice, this list of conditions and the following
     16 *        disclaimer.
     17 *
     18 *      - Redistributions in binary form must reproduce the above
     19 *        copyright notice, this list of conditions and the following
     20 *        disclaimer in the documentation and/or other materials
     21 *        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 OF
     25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
     27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
     28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     30 * 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}