1/* 2 * Copyright (c) 2004 Topspin Communications. All rights reserved. 3 * Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved. 4 * 5 * This software is available to you under a choice of one of two 6 * licenses. You may choose to be licensed under the terms of the GNU 7 * General Public License (GPL) Version 2, available from the file 8 * COPYING in the main directory of this source tree, or the 9 * OpenIB.org BSD license below: 10 * 11 * Redistribution and use in source and binary forms, with or 12 * without modification, are permitted provided that the following 13 * conditions are met: 14 * 15 * - Redistributions of source code must retain the above 16 * copyright notice, this list of conditions and the following 17 * disclaimer. 18 * 19 * - Redistributions in binary form must reproduce the above 20 * copyright notice, this list of conditions and the following 21 * disclaimer in the documentation and/or other materials 22 * provided with the distribution. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 31 * SOFTWARE. 32 */ 33 34#include <linux/errno.h> 35#include <linux/slab.h> 36#include <linux/bitmap.h> 37 38#include "c2.h" 39 40static int c2_alloc_mqsp_chunk(struct c2_dev *c2dev, gfp_t gfp_mask, 41 struct sp_chunk **head) 42{ 43 int i; 44 struct sp_chunk *new_head; 45 dma_addr_t dma_addr; 46 47 new_head = dma_alloc_coherent(&c2dev->pcidev->dev, PAGE_SIZE, 48 &dma_addr, gfp_mask); 49 if (new_head == NULL) 50 return -ENOMEM; 51 52 new_head->dma_addr = dma_addr; 53 pci_unmap_addr_set(new_head, mapping, new_head->dma_addr); 54 55 new_head->next = NULL; 56 new_head->head = 0; 57 58 /* build list where each index is the next free slot */ 59 for (i = 0; 60 i < (PAGE_SIZE - sizeof(struct sp_chunk) - 61 sizeof(u16)) / sizeof(u16) - 1; 62 i++) { 63 new_head->shared_ptr[i] = i + 1; 64 } 65 /* terminate list */ 66 new_head->shared_ptr[i] = 0xFFFF; 67 68 *head = new_head; 69 return 0; 70} 71 72int c2_init_mqsp_pool(struct c2_dev *c2dev, gfp_t gfp_mask, 73 struct sp_chunk **root) 74{ 75 return c2_alloc_mqsp_chunk(c2dev, gfp_mask, root); 76} 77 78void c2_free_mqsp_pool(struct c2_dev *c2dev, struct sp_chunk *root) 79{ 80 struct sp_chunk *next; 81 82 while (root) { 83 next = root->next; 84 dma_free_coherent(&c2dev->pcidev->dev, PAGE_SIZE, root, 85 pci_unmap_addr(root, mapping)); 86 root = next; 87 } 88} 89 90u16 *c2_alloc_mqsp(struct c2_dev *c2dev, struct sp_chunk *head, 91 dma_addr_t *dma_addr, gfp_t gfp_mask) 92{ 93 u16 mqsp; 94 95 while (head) { 96 mqsp = head->head; 97 if (mqsp != 0xFFFF) { 98 head->head = head->shared_ptr[mqsp]; 99 break; 100 } else if (head->next == NULL) { 101 if (c2_alloc_mqsp_chunk(c2dev, gfp_mask, &head->next) == 102 0) { 103 head = head->next; 104 mqsp = head->head; 105 head->head = head->shared_ptr[mqsp]; 106 break; 107 } else 108 return NULL; 109 } else 110 head = head->next; 111 } 112 if (head) { 113 *dma_addr = head->dma_addr + 114 ((unsigned long) &(head->shared_ptr[mqsp]) - 115 (unsigned long) head); 116 pr_debug("%s addr %p dma_addr %llx\n", __FUNCTION__, 117 &(head->shared_ptr[mqsp]), (unsigned long long) *dma_addr); 118 return &(head->shared_ptr[mqsp]); 119 } 120 return NULL; 121} 122 123void c2_free_mqsp(u16 * mqsp) 124{ 125 struct sp_chunk *head; 126 u16 idx; 127 128 /* The chunk containing this ptr begins at the page boundary */ 129 head = (struct sp_chunk *) ((unsigned long) mqsp & PAGE_MASK); 130 131 /* Link head to new mqsp */ 132 *mqsp = head->head; 133 134 /* Compute the shared_ptr index */ 135 idx = ((unsigned long) mqsp & ~PAGE_MASK) >> 1; 136 idx -= (unsigned long) &(((struct sp_chunk *) 0)->shared_ptr[0]) >> 1; 137 138 /* Point this index at the head */ 139 head->shared_ptr[idx] = head->head; 140 141 /* Point head at this index */ 142 head->head = idx; 143} 144