1// SPDX-License-Identifier: LGPL-2.1
 2/*
 3 * Copyright IBM Corporation, 2010
 4 * Author Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
 
 
 
 
 
 
 
 
 
 5 */
 6
 7#include <linux/mm.h>
 8#include <linux/module.h>
 
 
 
 9#include "trans_common.h"
10
11/**
12 * p9_release_pages - Release pages after the transaction.
13 * @pages: array of pages to be put
14 * @nr_pages: size of array
15 */
16void p9_release_pages(struct page **pages, int nr_pages)
 
17{
18	int i;
19
20	for (i = 0; i < nr_pages; i++)
21		if (pages[i])
22			put_page(pages[i]);
 
23}
24EXPORT_SYMBOL(p9_release_pages);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 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 *  @*private: PDU's private page of struct trans_rpage_info
 
25 */
26void
27p9_release_req_pages(struct trans_rpage_info *rpinfo)
28{
29	int i = 0;
30
31	while (rpinfo->rp_data[i] && rpinfo->rp_nr_pages--) {
32		put_page(rpinfo->rp_data[i]);
33		i++;
34	}
35}
36EXPORT_SYMBOL(p9_release_req_pages);
37
38/**
39 * p9_nr_pages - Return number of pages needed to accommodate the payload.
40 */
41int
42p9_nr_pages(struct p9_req_t *req)
43{
44	unsigned long start_page, end_page;
45	start_page =  (unsigned long)req->tc->pubuf >> PAGE_SHIFT;
46	end_page = ((unsigned long)req->tc->pubuf + req->tc->pbuf_size +
47			PAGE_SIZE - 1) >> PAGE_SHIFT;
48	return end_page - start_page;
49}
50EXPORT_SYMBOL(p9_nr_pages);
51
52/**
53 * payload_gup - Translates user buffer into kernel pages and
54 * pins them either for read/write through get_user_pages_fast().
55 * @req: Request to be sent to server.
56 * @pdata_off: data offset into the first page after translation (gup).
57 * @pdata_len: Total length of the IO. gup may not return requested # of pages.
58 * @nr_pages: number of pages to accommodate the payload
59 * @rw: Indicates if the pages are for read or write.
60 */
61int
62p9_payload_gup(struct p9_req_t *req, size_t *pdata_off, int *pdata_len,
63		int nr_pages, u8 rw)
64{
65	uint32_t first_page_bytes = 0;
66	int32_t pdata_mapped_pages;
67	struct trans_rpage_info  *rpinfo;
68
69	*pdata_off = (__force size_t)req->tc->pubuf & (PAGE_SIZE-1);
70
71	if (*pdata_off)
72		first_page_bytes = min(((size_t)PAGE_SIZE - *pdata_off),
73				       req->tc->pbuf_size);
74
75	rpinfo = req->tc->private;
76	pdata_mapped_pages = get_user_pages_fast((unsigned long)req->tc->pubuf,
77			nr_pages, rw, &rpinfo->rp_data[0]);
78	if (pdata_mapped_pages <= 0)
79		return pdata_mapped_pages;
80
81	rpinfo->rp_nr_pages = pdata_mapped_pages;
82	if (*pdata_off) {
83		*pdata_len = first_page_bytes;
84		*pdata_len += min((req->tc->pbuf_size - *pdata_len),
85				((size_t)pdata_mapped_pages - 1) << PAGE_SHIFT);
86	} else {
87		*pdata_len = min(req->tc->pbuf_size,
88				(size_t)pdata_mapped_pages << PAGE_SHIFT);
89	}
90	return 0;
91}
92EXPORT_SYMBOL(p9_payload_gup);