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
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 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 */
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 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 */
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, &current->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, &current->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, &current->mm->pinned_vm);
137}
138