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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 two6 * licenses. You may choose to be licensed under the terms of the GNU7 * General Public License (GPL) Version 2, available from the file8 * COPYING in the main directory of this source tree, or the9 * OpenIB.org BSD license below:10 *11 * Redistribution and use in source and binary forms, with or12 * without modification, are permitted provided that the following13 * conditions are met:14 *15 * - Redistributions of source code must retain the above16 * copyright notice, this list of conditions and the following17 * disclaimer.18 *19 * - Redistributions in binary form must reproduce the above20 * copyright notice, this list of conditions and the following21 * disclaimer in the documentation and/or other materials22 * 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 OF26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE31 * 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 40static 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 some51 * architectures.52 *53 * The powerpc iommu assigns dma_addrs in ascending order, so we don't54 * have to bother with retries or mapping a dummy page to insure we55 * 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 */59int 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 memory84 * @start_page: the start page85 * @num_pages: the number of pages86 * @p: the output page structures87 *88 * This function takes a given start page (page aligned user virtual89 * address) and pins it and the following specified number of pages. For90 * now, num_pages is always 1, but that will probably change at some point91 * (because caller is doing expected sends on a single virtually contiguous92 * buffer, so we can do all pages at once).93 */94int 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;123bail_release:124 __qib_release_user_pages(p, got, 0);125bail:126 atomic64_sub(num_pages, ¤t->mm->pinned_vm);127 return ret;128}129 130void 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