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 52 int 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 76 void 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 83 int 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 } 114 115 void 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