1 /* 2 * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved. 3 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, 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/mm.h> 35 #include <linux/device.h> 36 37 #include "qib.h" 38 39 static void __qib_release_user_pages(struct page **p, size_t num_pages, 40 int dirty) 41 { 42 size_t i; 43 44 for (i = 0; i < num_pages; i++) { 45 if (dirty) 46 set_page_dirty_lock(p[i]); 47 put_page(p[i]); 48 } 49 } 50 51 /* 52 * Call with current->mm->mmap_sem held. 53 */ 54 static int __qib_get_user_pages(unsigned long start_page, size_t num_pages, 55 struct page **p) 56 { 57 unsigned long lock_limit; 58 size_t got; 59 int ret; 60 61 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 62 63 if (num_pages > lock_limit && !capable(CAP_IPC_LOCK)) { 64 ret = -ENOMEM; 65 goto bail; 66 } 67 68 for (got = 0; got < num_pages; got += ret) { 69 ret = get_user_pages(current, current->mm, 70 start_page + got * PAGE_SIZE, 71 num_pages - got, 1, 1, 72 p + got, NULL); 73 if (ret < 0) 74 goto bail_release; 75 } 76 77 current->mm->pinned_vm += num_pages; 78 79 ret = 0; 80 goto bail; 81 82 bail_release: 83 __qib_release_user_pages(p, got, 0); 84 bail: 85 return ret; 86 } 87 88 /** 89 * qib_map_page - a safety wrapper around pci_map_page() 90 * 91 * A dma_addr of all 0's is interpreted by the chip as "disabled". 92 * Unfortunately, it can also be a valid dma_addr returned on some 93 * architectures. 94 * 95 * The powerpc iommu assigns dma_addrs in ascending order, so we don't 96 * have to bother with retries or mapping a dummy page to insure we 97 * don't just get the same mapping again. 98 * 99 * I'm sure we won't be so lucky with other iommu's, so FIXME. 100 */ 101 dma_addr_t qib_map_page(struct pci_dev *hwdev, struct page *page, 102 unsigned long offset, size_t size, int direction) 103 { 104 dma_addr_t phys; 105 106 phys = pci_map_page(hwdev, page, offset, size, direction); 107 108 if (phys == 0) { 109 pci_unmap_page(hwdev, phys, size, direction); 110 phys = pci_map_page(hwdev, page, offset, size, direction); 111 /* 112 * FIXME: If we get 0 again, we should keep this page, 113 * map another, then free the 0 page. 114 */ 115 } 116 117 return phys; 118 } 119 120 /** 121 * qib_get_user_pages - lock user pages into memory 122 * @start_page: the start page 123 * @num_pages: the number of pages 124 * @p: the output page structures 125 * 126 * This function takes a given start page (page aligned user virtual 127 * address) and pins it and the following specified number of pages. For 128 * now, num_pages is always 1, but that will probably change at some point 129 * (because caller is doing expected sends on a single virtually contiguous 130 * buffer, so we can do all pages at once). 131 */ 132 int qib_get_user_pages(unsigned long start_page, size_t num_pages, 133 struct page **p) 134 { 135 int ret; 136 137 down_write(¤t->mm->mmap_sem); 138 139 ret = __qib_get_user_pages(start_page, num_pages, p); 140 141 up_write(¤t->mm->mmap_sem); 142 143 return ret; 144 } 145 146 void qib_release_user_pages(struct page **p, size_t num_pages) 147 { 148 if (current->mm) /* during close after signal, mm can be NULL */ 149 down_write(¤t->mm->mmap_sem); 150 151 __qib_release_user_pages(p, num_pages, 1); 152 153 if (current->mm) { 154 current->mm->pinned_vm -= num_pages; 155 up_write(¤t->mm->mmap_sem); 156 } 157 } 158