Merge remote-tracking branch 'moduleh/module.h-split'
[linux-2.6/next.git] / drivers / infiniband / hw / ipath / ipath_user_pages.c
blobcfed5399f0746acc71e48f1c4d723c81774cc5e4
1 /*
2 * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
3 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
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:
11 * Redistribution and use in source and binary forms, with or
12 * without modification, are permitted provided that the following
13 * conditions are met:
15 * - Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
17 * disclaimer.
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.
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.
34 #include <linux/mm.h>
35 #include <linux/device.h>
36 #include <linux/slab.h>
37 #include <linux/sched.h>
39 #include "ipath_kernel.h"
41 static void __ipath_release_user_pages(struct page **p, size_t num_pages,
42 int dirty)
44 size_t i;
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]);
55 /* call with current->mm->mmap_sem held */
56 static int __ipath_get_user_pages(unsigned long start_page, size_t num_pages,
57 struct page **p, struct vm_area_struct **vma)
59 unsigned long lock_limit;
60 size_t got;
61 int ret;
63 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
65 if (num_pages > lock_limit) {
66 ret = -ENOMEM;
67 goto bail;
70 ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n",
71 (unsigned long) num_pages, start_page);
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, vma);
78 if (ret < 0)
79 goto bail_release;
82 current->mm->locked_vm += num_pages;
84 ret = 0;
85 goto bail;
87 bail_release:
88 __ipath_release_user_pages(p, got, 0);
89 bail:
90 return ret;
93 /**
94 * ipath_map_page - a safety wrapper around pci_map_page()
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.
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.
104 * I'm sure we won't be so lucky with other iommu's, so FIXME.
106 dma_addr_t ipath_map_page(struct pci_dev *hwdev, struct page *page,
107 unsigned long offset, size_t size, int direction)
109 dma_addr_t phys;
111 phys = pci_map_page(hwdev, page, offset, size, direction);
113 if (phys == 0) {
114 pci_unmap_page(hwdev, phys, size, direction);
115 phys = pci_map_page(hwdev, page, offset, size, direction);
117 * FIXME: If we get 0 again, we should keep this page,
118 * map another, then free the 0 page.
122 return phys;
126 * ipath_map_single - a safety wrapper around pci_map_single()
128 * Same idea as ipath_map_page().
130 dma_addr_t ipath_map_single(struct pci_dev *hwdev, void *ptr, size_t size,
131 int direction)
133 dma_addr_t phys;
135 phys = pci_map_single(hwdev, ptr, size, direction);
137 if (phys == 0) {
138 pci_unmap_single(hwdev, phys, size, direction);
139 phys = pci_map_single(hwdev, ptr, size, direction);
141 * FIXME: If we get 0 again, we should keep this page,
142 * map another, then free the 0 page.
146 return phys;
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
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).
161 int ipath_get_user_pages(unsigned long start_page, size_t num_pages,
162 struct page **p)
164 int ret;
166 down_write(&current->mm->mmap_sem);
168 ret = __ipath_get_user_pages(start_page, num_pages, p, NULL);
170 up_write(&current->mm->mmap_sem);
172 return ret;
175 void ipath_release_user_pages(struct page **p, size_t num_pages)
177 down_write(&current->mm->mmap_sem);
179 __ipath_release_user_pages(p, num_pages, 1);
181 current->mm->locked_vm -= num_pages;
183 up_write(&current->mm->mmap_sem);
186 struct ipath_user_pages_work {
187 struct work_struct work;
188 struct mm_struct *mm;
189 unsigned long num_pages;
192 static void user_pages_account(struct work_struct *_work)
194 struct ipath_user_pages_work *work =
195 container_of(_work, struct ipath_user_pages_work, work);
197 down_write(&work->mm->mmap_sem);
198 work->mm->locked_vm -= work->num_pages;
199 up_write(&work->mm->mmap_sem);
200 mmput(work->mm);
201 kfree(work);
204 void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
206 struct ipath_user_pages_work *work;
207 struct mm_struct *mm;
209 __ipath_release_user_pages(p, num_pages, 1);
211 mm = get_task_mm(current);
212 if (!mm)
213 return;
215 work = kmalloc(sizeof(*work), GFP_KERNEL);
216 if (!work)
217 goto bail_mm;
219 INIT_WORK(&work->work, user_pages_account);
220 work->mm = mm;
221 work->num_pages = num_pages;
223 queue_work(ib_wq, &work->work);
224 return;
226 bail_mm:
227 mmput(mm);
228 return;