cfg80211: Validate frequencies nested in NL80211_ATTR_SCAN_FREQUENCIES
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / 9p / trans_common.c
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1/*
2 * Copyright IBM Corporation, 2010
3 * Author Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2.1 of the GNU Lesser General Public License
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 *
13 */
14
15#include <linux/slab.h>
16#include <linux/module.h>
17#include <net/9p/9p.h>
18#include <net/9p/client.h>
19#include <linux/scatterlist.h>
20#include "trans_common.h"
21
22/**
23 * p9_release_req_pages - Release pages after the transaction.
022cae36 24 */
abfa034e 25void p9_release_pages(struct page **pages, int nr_pages)
022cae36 26{
53effe16
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27 int i;
28
29 for (i = 0; i < nr_pages; i++)
30 if (pages[i])
31 put_page(pages[i]);
022cae36 32}
abfa034e 33EXPORT_SYMBOL(p9_release_pages);
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34
35/**
25985edc 36 * p9_nr_pages - Return number of pages needed to accommodate the payload.
022cae36 37 */
abfa034e 38int p9_nr_pages(char *data, int len)
022cae36 39{
472e7f9f 40 unsigned long start_page, end_page;
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41 start_page = (unsigned long)data >> PAGE_SHIFT;
42 end_page = ((unsigned long)data + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
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43 return end_page - start_page;
44}
45EXPORT_SYMBOL(p9_nr_pages);
46
47/**
48 * payload_gup - Translates user buffer into kernel pages and
49 * pins them either for read/write through get_user_pages_fast().
50 * @req: Request to be sent to server.
51 * @pdata_off: data offset into the first page after translation (gup).
52 * @pdata_len: Total length of the IO. gup may not return requested # of pages.
25985edc 53 * @nr_pages: number of pages to accommodate the payload
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54 * @rw: Indicates if the pages are for read or write.
55 */
022cae36 56
abfa034e
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57int p9_payload_gup(char *data, int *nr_pages, struct page **pages, int write)
58{
59 int nr_mapped_pages;
022cae36 60
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61 nr_mapped_pages = get_user_pages_fast((unsigned long)data,
62 *nr_pages, write, pages);
63 if (nr_mapped_pages <= 0)
64 return nr_mapped_pages;
022cae36 65
abfa034e 66 *nr_pages = nr_mapped_pages;
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67 return 0;
68}
69EXPORT_SYMBOL(p9_payload_gup);