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 (3028B)

      1/*
      2 * Copyright (c) 2013-2015, Mellanox Technologies. 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/kref.h>
     34#include <linux/slab.h>
     35#include <linux/sched/mm.h>
     36#include <rdma/ib_umem.h>
     37
     38#include "mlx5_ib.h"
     39
     40struct mlx5_ib_user_db_page {
     41	struct list_head	list;
     42	struct ib_umem	       *umem;
     43	unsigned long		user_virt;
     44	int			refcnt;
     45	struct mm_struct	*mm;
     46};
     47
     48int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt,
     49			struct mlx5_db *db)
     50{
     51	struct mlx5_ib_user_db_page *page;
     52	int err = 0;
     53
     54	mutex_lock(&context->db_page_mutex);
     55
     56	list_for_each_entry(page, &context->db_page_list, list)
     57		if ((current->mm == page->mm) &&
     58		    (page->user_virt == (virt & PAGE_MASK)))
     59			goto found;
     60
     61	page = kmalloc(sizeof(*page), GFP_KERNEL);
     62	if (!page) {
     63		err = -ENOMEM;
     64		goto out;
     65	}
     66
     67	page->user_virt = (virt & PAGE_MASK);
     68	page->refcnt    = 0;
     69	page->umem = ib_umem_get(context->ibucontext.device, virt & PAGE_MASK,
     70				 PAGE_SIZE, 0);
     71	if (IS_ERR(page->umem)) {
     72		err = PTR_ERR(page->umem);
     73		kfree(page);
     74		goto out;
     75	}
     76	mmgrab(current->mm);
     77	page->mm = current->mm;
     78
     79	list_add(&page->list, &context->db_page_list);
     80
     81found:
     82	db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) +
     83		  (virt & ~PAGE_MASK);
     84	db->u.user_page = page;
     85	++page->refcnt;
     86
     87out:
     88	mutex_unlock(&context->db_page_mutex);
     89
     90	return err;
     91}
     92
     93void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db)
     94{
     95	mutex_lock(&context->db_page_mutex);
     96
     97	if (!--db->u.user_page->refcnt) {
     98		list_del(&db->u.user_page->list);
     99		mmdrop(db->u.user_page->mm);
    100		ib_umem_release(db->u.user_page->umem);
    101		kfree(db->u.user_page);
    102	}
    103
    104	mutex_unlock(&context->db_page_mutex);
    105}