cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pvrdma_doorbell.c (3993B)

      1/*
      2 * Copyright (c) 2012-2016 VMware, Inc.  All rights reserved.
      3 *
      4 * This program is free software; you can redistribute it and/or
      5 * modify it under the terms of EITHER the GNU General Public License
      6 * version 2 as published by the Free Software Foundation or the BSD
      7 * 2-Clause License. This program is distributed in the hope that it
      8 * will be useful, but WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED
      9 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
     10 * See the GNU General Public License version 2 for more details at
     11 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
     12 *
     13 * You should have received a copy of the GNU General Public License
     14 * along with this program available in the file COPYING in the main
     15 * directory of this source tree.
     16 *
     17 * The BSD 2-Clause License
     18 *
     19 *     Redistribution and use in source and binary forms, with or
     20 *     without modification, are permitted provided that the following
     21 *     conditions are met:
     22 *
     23 *      - Redistributions of source code must retain the above
     24 *        copyright notice, this list of conditions and the following
     25 *        disclaimer.
     26 *
     27 *      - Redistributions in binary form must reproduce the above
     28 *        copyright notice, this list of conditions and the following
     29 *        disclaimer in the documentation and/or other materials
     30 *        provided with the distribution.
     31 *
     32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     35 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     36 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     37 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     38 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     39 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     42 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     43 * OF THE POSSIBILITY OF SUCH DAMAGE.
     44 */
     45
     46#include <linux/bitmap.h>
     47#include <linux/errno.h>
     48#include <linux/slab.h>
     49
     50#include "pvrdma.h"
     51
     52int pvrdma_uar_table_init(struct pvrdma_dev *dev)
     53{
     54	u32 num = dev->dsr->caps.max_uar;
     55	u32 mask = num - 1;
     56	struct pvrdma_id_table *tbl = &dev->uar_table.tbl;
     57
     58	if (!is_power_of_2(num))
     59		return -EINVAL;
     60
     61	tbl->last = 0;
     62	tbl->top = 0;
     63	tbl->max = num;
     64	tbl->mask = mask;
     65	spin_lock_init(&tbl->lock);
     66	tbl->table = bitmap_zalloc(num, GFP_KERNEL);
     67	if (!tbl->table)
     68		return -ENOMEM;
     69
     70	/* 0th UAR is taken by the device. */
     71	__set_bit(0, tbl->table);
     72
     73	return 0;
     74}
     75
     76void pvrdma_uar_table_cleanup(struct pvrdma_dev *dev)
     77{
     78	struct pvrdma_id_table *tbl = &dev->uar_table.tbl;
     79
     80	bitmap_free(tbl->table);
     81}
     82
     83int pvrdma_uar_alloc(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar)
     84{
     85	struct pvrdma_id_table *tbl;
     86	unsigned long flags;
     87	u32 obj;
     88
     89	tbl = &dev->uar_table.tbl;
     90
     91	spin_lock_irqsave(&tbl->lock, flags);
     92	obj = find_next_zero_bit(tbl->table, tbl->max, tbl->last);
     93	if (obj >= tbl->max) {
     94		tbl->top = (tbl->top + tbl->max) & tbl->mask;
     95		obj = find_first_zero_bit(tbl->table, tbl->max);
     96	}
     97
     98	if (obj >= tbl->max) {
     99		spin_unlock_irqrestore(&tbl->lock, flags);
    100		return -ENOMEM;
    101	}
    102
    103	__set_bit(obj, tbl->table);
    104	obj |= tbl->top;
    105
    106	spin_unlock_irqrestore(&tbl->lock, flags);
    107
    108	uar->index = obj;
    109	uar->pfn = (pci_resource_start(dev->pdev, PVRDMA_PCI_RESOURCE_UAR) >>
    110		    PAGE_SHIFT) + uar->index;
    111
    112	return 0;
    113}
    114
    115void pvrdma_uar_free(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar)
    116{
    117	struct pvrdma_id_table *tbl = &dev->uar_table.tbl;
    118	unsigned long flags;
    119	u32 obj;
    120
    121	obj = uar->index & (tbl->max - 1);
    122	spin_lock_irqsave(&tbl->lock, flags);
    123	__clear_bit(obj, tbl->table);
    124	tbl->last = min(tbl->last, obj);
    125	tbl->top = (tbl->top + tbl->max) & tbl->mask;
    126	spin_unlock_irqrestore(&tbl->lock, flags);
    127}