LXR linux/drivers/infiniband/hw/vmw_pvrdma/pvrdma

   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 = kcalloc(BITS_TO_LONGS(num), sizeof(long), 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        kfree(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}
 128