]>
Commit | Line | Data |
---|---|---|
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. | |
24 | */ | |
25 | void p9_release_pages(struct page **pages, int nr_pages) | |
26 | { | |
27 | int i; | |
28 | ||
29 | for (i = 0; i < nr_pages; i++) | |
30 | if (pages[i]) | |
31 | put_page(pages[i]); | |
32 | } | |
33 | EXPORT_SYMBOL(p9_release_pages); | |
34 | ||
35 | /** | |
36 | * p9_nr_pages - Return number of pages needed to accommodate the payload. | |
37 | */ | |
38 | int p9_nr_pages(char *data, int len) | |
39 | { | |
40 | unsigned long start_page, end_page; | |
41 | start_page = (unsigned long)data >> PAGE_SHIFT; | |
42 | end_page = ((unsigned long)data + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
43 | return end_page - start_page; | |
44 | } | |
45 | EXPORT_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. | |
53 | * @nr_pages: number of pages to accommodate the payload | |
54 | * @rw: Indicates if the pages are for read or write. | |
55 | */ | |
56 | ||
57 | int p9_payload_gup(char *data, int *nr_pages, struct page **pages, int write) | |
58 | { | |
59 | int nr_mapped_pages; | |
60 | ||
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; | |
65 | ||
66 | *nr_pages = nr_mapped_pages; | |
67 | return 0; | |
68 | } | |
69 | EXPORT_SYMBOL(p9_payload_gup); |