ia64/linux-2.6.18-xen.hg

view net/sunrpc/socklib.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
1 /*
2 * linux/net/sunrpc/socklib.c
3 *
4 * Common socket helper routines for RPC client and server
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 */
9 #include <linux/compiler.h>
10 #include <linux/netdevice.h>
11 #include <linux/skbuff.h>
12 #include <linux/types.h>
13 #include <linux/pagemap.h>
14 #include <linux/udp.h>
15 #include <linux/sunrpc/xdr.h>
18 /**
19 * skb_read_bits - copy some data bits from skb to internal buffer
20 * @desc: sk_buff copy helper
21 * @to: copy destination
22 * @len: number of bytes to copy
23 *
24 * Possibly called several times to iterate over an sk_buff and copy
25 * data out of it.
26 */
27 static size_t skb_read_bits(skb_reader_t *desc, void *to, size_t len)
28 {
29 if (len > desc->count)
30 len = desc->count;
31 if (skb_copy_bits(desc->skb, desc->offset, to, len))
32 return 0;
33 desc->count -= len;
34 desc->offset += len;
35 return len;
36 }
38 /**
39 * skb_read_and_csum_bits - copy and checksum from skb to buffer
40 * @desc: sk_buff copy helper
41 * @to: copy destination
42 * @len: number of bytes to copy
43 *
44 * Same as skb_read_bits, but calculate a checksum at the same time.
45 */
46 static size_t skb_read_and_csum_bits(skb_reader_t *desc, void *to, size_t len)
47 {
48 unsigned int csum2, pos;
50 if (len > desc->count)
51 len = desc->count;
52 pos = desc->offset;
53 csum2 = skb_copy_and_csum_bits(desc->skb, pos, to, len, 0);
54 desc->csum = csum_block_add(desc->csum, csum2, pos);
55 desc->count -= len;
56 desc->offset += len;
57 return len;
58 }
60 /**
61 * xdr_partial_copy_from_skb - copy data out of an skb
62 * @xdr: target XDR buffer
63 * @base: starting offset
64 * @desc: sk_buff copy helper
65 * @copy_actor: virtual method for copying data
66 *
67 */
68 ssize_t xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, skb_reader_t *desc, skb_read_actor_t copy_actor)
69 {
70 struct page **ppage = xdr->pages;
71 unsigned int len, pglen = xdr->page_len;
72 ssize_t copied = 0;
73 int ret;
75 len = xdr->head[0].iov_len;
76 if (base < len) {
77 len -= base;
78 ret = copy_actor(desc, (char *)xdr->head[0].iov_base + base, len);
79 copied += ret;
80 if (ret != len || !desc->count)
81 goto out;
82 base = 0;
83 } else
84 base -= len;
86 if (unlikely(pglen == 0))
87 goto copy_tail;
88 if (unlikely(base >= pglen)) {
89 base -= pglen;
90 goto copy_tail;
91 }
92 if (base || xdr->page_base) {
93 pglen -= base;
94 base += xdr->page_base;
95 ppage += base >> PAGE_CACHE_SHIFT;
96 base &= ~PAGE_CACHE_MASK;
97 }
98 do {
99 char *kaddr;
101 /* ACL likes to be lazy in allocating pages - ACLs
102 * are small by default but can get huge. */
103 if (unlikely(*ppage == NULL)) {
104 *ppage = alloc_page(GFP_ATOMIC);
105 if (unlikely(*ppage == NULL)) {
106 if (copied == 0)
107 copied = -ENOMEM;
108 goto out;
109 }
110 }
112 len = PAGE_CACHE_SIZE;
113 kaddr = kmap_atomic(*ppage, KM_SKB_SUNRPC_DATA);
114 if (base) {
115 len -= base;
116 if (pglen < len)
117 len = pglen;
118 ret = copy_actor(desc, kaddr + base, len);
119 base = 0;
120 } else {
121 if (pglen < len)
122 len = pglen;
123 ret = copy_actor(desc, kaddr, len);
124 }
125 flush_dcache_page(*ppage);
126 kunmap_atomic(kaddr, KM_SKB_SUNRPC_DATA);
127 copied += ret;
128 if (ret != len || !desc->count)
129 goto out;
130 ppage++;
131 } while ((pglen -= len) != 0);
132 copy_tail:
133 len = xdr->tail[0].iov_len;
134 if (base < len)
135 copied += copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);
136 out:
137 return copied;
138 }
140 /**
141 * csum_partial_copy_to_xdr - checksum and copy data
142 * @xdr: target XDR buffer
143 * @skb: source skb
144 *
145 * We have set things up such that we perform the checksum of the UDP
146 * packet in parallel with the copies into the RPC client iovec. -DaveM
147 */
148 int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
149 {
150 skb_reader_t desc;
152 desc.skb = skb;
153 desc.offset = sizeof(struct udphdr);
154 desc.count = skb->len - desc.offset;
156 if (skb->ip_summed == CHECKSUM_UNNECESSARY)
157 goto no_checksum;
159 desc.csum = csum_partial(skb->data, desc.offset, skb->csum);
160 if (xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_and_csum_bits) < 0)
161 return -1;
162 if (desc.offset != skb->len) {
163 unsigned int csum2;
164 csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0);
165 desc.csum = csum_block_add(desc.csum, csum2, desc.offset);
166 }
167 if (desc.count)
168 return -1;
169 if ((unsigned short)csum_fold(desc.csum))
170 return -1;
171 if (unlikely(skb->ip_summed == CHECKSUM_HW))
172 netdev_rx_csum_fault(skb->dev);
173 return 0;
174 no_checksum:
175 if (xdr_partial_copy_from_skb(xdr, 0, &desc, skb_read_bits) < 0)
176 return -1;
177 if (desc.count)
178 return -1;
179 return 0;
180 }