1/* 2 * Copyright (c) 2006, 2007 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#include <linux/slab.h> 37#include <linux/sched.h> 38 39#include "ipath_kernel.h" 40 41static void __ipath_release_user_pages(struct page **p, size_t num_pages, 42 int dirty) 43{ 44 size_t i; 45 46 for (i = 0; i < num_pages; i++) { 47 ipath_cdbg(MM, "%lu/%lu put_page %p\n", (unsigned long) i, 48 (unsigned long) num_pages, p[i]); 49 if (dirty) 50 set_page_dirty_lock(p[i]); 51 put_page(p[i]); 52 } 53} 54 55/* call with current->mm->mmap_sem held */ 56static int __ipath_get_user_pages(unsigned long start_page, size_t num_pages, 57 struct page **p) 58{ 59 unsigned long lock_limit; 60 size_t got; 61 int ret; 62 63 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 64 65 if (num_pages > lock_limit) { 66 ret = -ENOMEM; 67 goto bail; 68 } 69 70 ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n", 71 (unsigned long) num_pages, start_page); 72 73 for (got = 0; got < num_pages; got += ret) { 74 ret = get_user_pages(current, current->mm, 75 start_page + got * PAGE_SIZE, 76 num_pages - got, 1, 1, 77 p + got, NULL); 78 if (ret < 0) 79 goto bail_release; 80 } 81 82 current->mm->pinned_vm += num_pages; 83 84 ret = 0; 85 goto bail; 86 87bail_release: 88 __ipath_release_user_pages(p, got, 0); 89bail: 90 return ret; 91} 92 93/** 94 * ipath_map_page - a safety wrapper around pci_map_page() 95 * 96 * A dma_addr of all 0's is interpreted by the chip as "disabled". 97 * Unfortunately, it can also be a valid dma_addr returned on some 98 * architectures. 99 * 100 * The powerpc iommu assigns dma_addrs in ascending order, so we don't 101 * have to bother with retries or mapping a dummy page to insure we 102 * don't just get the same mapping again. 103 * 104 * I'm sure we won't be so lucky with other iommu's, so FIXME. 105 */ 106dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page, 107 unsigned long offset, size_t size, int direction) 108{ 109 dma_addr_t phys; 110 111 phys = pci_map_page(hwdev, page, offset, size, direction); 112 113 if (phys == 0) { 114 pci_unmap_page(hwdev, phys, size, direction); 115 phys = pci_map_page(hwdev, page, offset, size, direction); 116 /* 117 * FIXME: If we get 0 again, we should keep this page, 118 * map another, then free the 0 page. 119 */ 120 } 121 122 return phys; 123} 124 125/** 126 * ipath_map_single - a safety wrapper around pci_map_single() 127 * 128 * Same idea as ipath_map_page(). 129 */ 130dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size, 131 int direction) 132{ 133 dma_addr_t phys; 134 135 phys = pci_map_single(hwdev, ptr, size, direction); 136 137 if (phys == 0) { 138 pci_unmap_single(hwdev, phys, size, direction); 139 phys = pci_map_single(hwdev, ptr, size, direction); 140 /* 141 * FIXME: If we get 0 again, we should keep this page, 142 * map another, then free the 0 page. 143 */ 144 } 145 146 return phys; 147} 148 149/** 150 * ipath_get_user_pages - lock user pages into memory 151 * @start_page: the start page 152 * @num_pages: the number of pages 153 * @p: the output page structures 154 * 155 * This function takes a given start page (page aligned user virtual 156 * address) and pins it and the following specified number of pages. For 157 * now, num_pages is always 1, but that will probably change at some point 158 * (because caller is doing expected sends on a single virtually contiguous 159 * buffer, so we can do all pages at once). 160 */ 161int ipath_get_user_pages(unsigned long start_page, size_t num_pages, 162 struct page **p) 163{ 164 int ret; 165 166 down_write(¤t->mm->mmap_sem); 167 168 ret = __ipath_get_user_pages(start_page, num_pages, p); 169 170 up_write(¤t->mm->mmap_sem); 171 172 return ret; 173} 174 175void ipath_release_user_pages(struct page **p, size_t num_pages) 176{ 177 down_write(¤t->mm->mmap_sem); 178 179 __ipath_release_user_pages(p, num_pages, 1); 180 181 current->mm->pinned_vm -= num_pages; 182 183 up_write(¤t->mm->mmap_sem); 184} 185 186struct ipath_user_pages_work { 187 struct work_struct work; 188 struct mm_struct *mm; 189 unsigned long num_pages; 190}; 191 192static void user_pages_account(struct work_struct *_work) 193{ 194 struct ipath_user_pages_work *work = 195 container_of(_work, struct ipath_user_pages_work, work); 196 197 down_write(&work->mm->mmap_sem); 198 work->mm->pinned_vm -= work->num_pages; 199 up_write(&work->mm->mmap_sem); 200 mmput(work->mm); 201 kfree(work); 202} 203 204void ipath_release_user_pages_on_close(struct page **p, size_t num_pages) 205{ 206 struct ipath_user_pages_work *work; 207 struct mm_struct *mm; 208 209 __ipath_release_user_pages(p, num_pages, 1); 210 211 mm = get_task_mm(current); 212 if (!mm) 213 return; 214 215 work = kmalloc(sizeof(*work), GFP_KERNEL); 216 if (!work) 217 goto bail_mm; 218 219 INIT_WORK(&work->work, user_pages_account); 220 work->mm = mm; 221 work->num_pages = num_pages; 222 223 queue_work(ib_wq, &work->work); 224 return; 225 226bail_mm: 227 mmput(mm); 228 return; 229} 230