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 unpin_user_pages_dirty_lock(p, num_pages, dirty); 44 } 45 46 /* 47 * qib_map_page - a safety wrapper around pci_map_page() 48 * 49 * A dma_addr of all 0's is interpreted by the chip as "disabled". 50 * Unfortunately, it can also be a valid dma_addr returned on some 51 * architectures. 52 * 53 * The powerpc iommu assigns dma_addrs in ascending order, so we don't 54 * have to bother with retries or mapping a dummy page to insure we 55 * don't just get the same mapping again. 56 * 57 * I'm sure we won't be so lucky with other iommu's, so FIXME. 58 */ 59 int qib_map_page(struct pci_dev *hwdev, struct page *page, dma_addr_t *daddr) 60 { 61 dma_addr_t phys; 62 63 phys = dma_map_page(&hwdev->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE); 64 if (dma_mapping_error(&hwdev->dev, phys)) 65 return -ENOMEM; 66 67 if (!phys) { 68 dma_unmap_page(&hwdev->dev, phys, PAGE_SIZE, DMA_FROM_DEVICE); 69 phys = dma_map_page(&hwdev->dev, page, 0, PAGE_SIZE, 70 DMA_FROM_DEVICE); 71 if (dma_mapping_error(&hwdev->dev, phys)) 72 return -ENOMEM; 73 /* 74 * FIXME: If we get 0 again, we should keep this page, 75 * map another, then free the 0 page. 76 */ 77 } 78 *daddr = phys; 79 return 0; 80 } 81 82 /** 83 * qib_get_user_pages - lock user pages into memory 84 * @start_page: the start page 85 * @num_pages: the number of pages 86 * @p: the output page structures 87 * 88 * This function takes a given start page (page aligned user virtual 89 * address) and pins it and the following specified number of pages. For 90 * now, num_pages is always 1, but that will probably change at some point 91 * (because caller is doing expected sends on a single virtually contiguous 92 * buffer, so we can do all pages at once). 93 */ 94 int qib_get_user_pages(unsigned long start_page, size_t num_pages, 95 struct page **p) 96 { 97 unsigned long locked, lock_limit; 98 size_t got; 99 int ret; 100 101 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; 102 locked = atomic64_add_return(num_pages, ¤t->mm->pinned_vm); 103 104 if (locked > lock_limit && !capable(CAP_IPC_LOCK)) { 105 ret = -ENOMEM; 106 goto bail; 107 } 108 109 mmap_read_lock(current->mm); 110 for (got = 0; got < num_pages; got += ret) { 111 ret = pin_user_pages(start_page + got * PAGE_SIZE, 112 num_pages - got, 113 FOLL_LONGTERM | FOLL_WRITE, 114 p + got); 115 if (ret < 0) { 116 mmap_read_unlock(current->mm); 117 goto bail_release; 118 } 119 } 120 mmap_read_unlock(current->mm); 121 122 return 0; 123 bail_release: 124 __qib_release_user_pages(p, got, 0); 125 bail: 126 atomic64_sub(num_pages, ¤t->mm->pinned_vm); 127 return ret; 128 } 129 130 void qib_release_user_pages(struct page **p, size_t num_pages) 131 { 132 __qib_release_user_pages(p, num_pages, 1); 133 134 /* during close after signal, mm can be NULL */ 135 if (current->mm) 136 atomic64_sub(num_pages, ¤t->mm->pinned_vm); 137 } 138