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/sched/signal.h> 36 #include <linux/device.h> 37 38 #include "qib.h" 39 40 static void __qib_release_user_pages(struct page **p, size_t num_pages, 41 int dirty) 42 { 43 size_t i; 44 45 for (i = 0; i < num_pages; i++) { 46 if (dirty) 47 set_page_dirty_lock(p[i]); 48 put_page(p[i]); 49 } 50 } 51 52 /* 53 * Call with current->mm->mmap_sem held. 54 */ 55 static int __qib_get_user_pages(unsigned long start_page, size_t num_pages, 56 struct page **p) 57 { 58 unsigned long lock_limit; 59 size_t got; 60 int ret; 61 62 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 63 64 if (num_pages > lock_limit && !capable(CAP_IPC_LOCK)) { 65 ret = -ENOMEM; 66 goto bail; 67 } 68 69 for (got = 0; got < num_pages; got += ret) { 70 ret = get_user_pages(start_page + got * PAGE_SIZE, 71 num_pages - got, 72 FOLL_WRITE | FOLL_FORCE, 73 p + got, NULL); 74 if (ret < 0) 75 goto bail_release; 76 } 77 78 current->mm->pinned_vm += num_pages; 79 80 ret = 0; 81 goto bail; 82 83 bail_release: 84 __qib_release_user_pages(p, got, 0); 85 bail: 86 return ret; 87 } 88 89 /** 90 * qib_map_page - a safety wrapper around pci_map_page() 91 * 92 * A dma_addr of all 0's is interpreted by the chip as "disabled". 93 * Unfortunately, it can also be a valid dma_addr returned on some 94 * architectures. 95 * 96 * The powerpc iommu assigns dma_addrs in ascending order, so we don't 97 * have to bother with retries or mapping a dummy page to insure we 98 * don't just get the same mapping again. 99 * 100 * I'm sure we won't be so lucky with other iommu's, so FIXME. 101 */ 102 int qib_map_page(struct pci_dev *hwdev, struct page *page, dma_addr_t *daddr) 103 { 104 dma_addr_t phys; 105 106 phys = pci_map_page(hwdev, page, 0, PAGE_SIZE, PCI_DMA_FROMDEVICE); 107 if (pci_dma_mapping_error(hwdev, phys)) 108 return -ENOMEM; 109 110 if (!phys) { 111 pci_unmap_page(hwdev, phys, PAGE_SIZE, PCI_DMA_FROMDEVICE); 112 phys = pci_map_page(hwdev, page, 0, PAGE_SIZE, 113 PCI_DMA_FROMDEVICE); 114 if (pci_dma_mapping_error(hwdev, phys)) 115 return -ENOMEM; 116 /* 117 * FIXME: If we get 0 again, we should keep this page, 118 * map another, then free the 0 page. 119 */ 120 } 121 *daddr = phys; 122 return 0; 123 } 124 125 /** 126 * qib_get_user_pages - lock user pages into memory 127 * @start_page: the start page 128 * @num_pages: the number of pages 129 * @p: the output page structures 130 * 131 * This function takes a given start page (page aligned user virtual 132 * address) and pins it and the following specified number of pages. For 133 * now, num_pages is always 1, but that will probably change at some point 134 * (because caller is doing expected sends on a single virtually contiguous 135 * buffer, so we can do all pages at once). 136 */ 137 int qib_get_user_pages(unsigned long start_page, size_t num_pages, 138 struct page **p) 139 { 140 int ret; 141 142 down_write(¤t->mm->mmap_sem); 143 144 ret = __qib_get_user_pages(start_page, num_pages, p); 145 146 up_write(¤t->mm->mmap_sem); 147 148 return ret; 149 } 150 151 void qib_release_user_pages(struct page **p, size_t num_pages) 152 { 153 if (current->mm) /* during close after signal, mm can be NULL */ 154 down_write(¤t->mm->mmap_sem); 155 156 __qib_release_user_pages(p, num_pages, 1); 157 158 if (current->mm) { 159 current->mm->pinned_vm -= num_pages; 160 up_write(¤t->mm->mmap_sem); 161 } 162 } 163