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1da177e Linux-2.6.12-rc2
Linus Torvalds authored
1 /*
2 * xor.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1996, 1997, 1998, 1999, 2000,
5 * Ingo Molnar, Matti Aarnio, Jakub Jelinek, Richard Henderson.
6 *
7 * Dispatch optimized RAID-5 checksumming functions.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2, or (at your option)
12 * any later version.
13 *
14 * You should have received a copy of the GNU General Public License
15 * (for example /usr/src/linux/COPYING); if not, write to the Free
16 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17 */
18
19 #define BH_TRACE 0
20 #include <linux/module.h>
5a0e3ad include cleanup: Update gfp.h and slab.h includes to prepare for breakin...
Tejun Heo authored
21 #include <linux/gfp.h>
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
22 #include <linux/raid/xor.h>
bff6197 @neilbrown md: move lots of #include lines out of .h files and into .c
neilbrown authored
23 #include <linux/jiffies.h>
56a5199 @jtkukunas crypto: disable preemption while benchmarking RAID5 xor checksumming
jtkukunas authored
24 #include <linux/preempt.h>
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
25 #include <asm/xor.h>
26
27 /* The xor routines to use. */
28 static struct xor_block_template *active_template;
29
30 void
9bc89cd @djbw async_tx: add the async_tx api
djbw authored
31 xor_blocks(unsigned int src_count, unsigned int bytes, void *dest, void **srcs)
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
32 {
9bc89cd @djbw async_tx: add the async_tx api
djbw authored
33 unsigned long *p1, *p2, *p3, *p4;
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
34
9bc89cd @djbw async_tx: add the async_tx api
djbw authored
35 p1 = (unsigned long *) srcs[0];
36 if (src_count == 1) {
37 active_template->do_2(bytes, dest, p1);
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
38 return;
39 }
40
9bc89cd @djbw async_tx: add the async_tx api
djbw authored
41 p2 = (unsigned long *) srcs[1];
42 if (src_count == 2) {
43 active_template->do_3(bytes, dest, p1, p2);
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
44 return;
45 }
46
9bc89cd @djbw async_tx: add the async_tx api
djbw authored
47 p3 = (unsigned long *) srcs[2];
48 if (src_count == 3) {
49 active_template->do_4(bytes, dest, p1, p2, p3);
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
50 return;
51 }
52
9bc89cd @djbw async_tx: add the async_tx api
djbw authored
53 p4 = (unsigned long *) srcs[3];
54 active_template->do_5(bytes, dest, p1, p2, p3, p4);
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
55 }
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
56 EXPORT_SYMBOL(xor_blocks);
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
57
58 /* Set of all registered templates. */
59 static struct xor_block_template *template_list;
60
61 #define BENCH_SIZE (PAGE_SIZE)
62
63 static void
64 do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
65 {
66 int speed;
6a32847 @jtkukunas crypto: wait for a full jiffy in do_xor_speed
jtkukunas authored
67 unsigned long now, j;
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
68 int i, count, max;
69
70 tmpl->next = template_list;
71 template_list = tmpl;
72
56a5199 @jtkukunas crypto: disable preemption while benchmarking RAID5 xor checksumming
jtkukunas authored
73 preempt_disable();
74
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
75 /*
76 * Count the number of XORs done during a whole jiffy, and use
77 * this to calculate the speed of checksumming. We use a 2-page
78 * allocation to have guaranteed color L1-cache layout.
79 */
80 max = 0;
81 for (i = 0; i < 5; i++) {
6a32847 @jtkukunas crypto: wait for a full jiffy in do_xor_speed
jtkukunas authored
82 j = jiffies;
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
83 count = 0;
6a32847 @jtkukunas crypto: wait for a full jiffy in do_xor_speed
jtkukunas authored
84 while ((now = jiffies) == j)
85 cpu_relax();
86 while (time_before(jiffies, now + 1)) {
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
87 mb(); /* prevent loop optimzation */
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
88 tmpl->do_2(BENCH_SIZE, b1, b2);
89 mb();
90 count++;
91 mb();
92 }
93 if (count > max)
94 max = count;
95 }
96
56a5199 @jtkukunas crypto: disable preemption while benchmarking RAID5 xor checksumming
jtkukunas authored
97 preempt_enable();
98
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
99 speed = max * (HZ * BENCH_SIZE / 1024);
100 tmpl->speed = speed;
101
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
102 printk(KERN_INFO " %-10s: %5d.%03d MB/sec\n", tmpl->name,
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
103 speed / 1000, speed % 1000);
104 }
105
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
106 static int __init
107 calibrate_xor_blocks(void)
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
108 {
109 void *b1, *b2;
110 struct xor_block_template *f, *fastest;
111
33f65df @vegard crypto: don't track xor test pages with kmemcheck
vegard authored
112 /*
113 * Note: Since the memory is not actually used for _anything_ but to
114 * test the XOR speed, we don't really want kmemcheck to warn about
115 * reading uninitialized bytes here.
116 */
117 b1 = (void *) __get_free_pages(GFP_KERNEL | __GFP_NOTRACK, 2);
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
118 if (!b1) {
119 printk(KERN_WARNING "xor: Yikes! No memory available.\n");
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
120 return -ENOMEM;
121 }
122 b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
123
124 /*
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
125 * If this arch/cpu has a short-circuited selection, don't loop through
126 * all the possible functions, just test the best one
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
127 */
128
129 fastest = NULL;
130
131 #ifdef XOR_SELECT_TEMPLATE
132 fastest = XOR_SELECT_TEMPLATE(fastest);
133 #endif
134
135 #define xor_speed(templ) do_xor_speed((templ), b1, b2)
136
137 if (fastest) {
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
138 printk(KERN_INFO "xor: automatically using best "
d788fec crypto, xor: Sanitize checksumming function selection output
Borislav Petkov authored
139 "checksumming function:\n");
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
140 xor_speed(fastest);
d788fec crypto, xor: Sanitize checksumming function selection output
Borislav Petkov authored
141 goto out;
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
142 } else {
9bc89cd @djbw async_tx: add the async_tx api
djbw authored
143 printk(KERN_INFO "xor: measuring software checksum speed\n");
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
144 XOR_TRY_TEMPLATES;
145 fastest = template_list;
146 for (f = fastest; f; f = f->next)
147 if (f->speed > fastest->speed)
148 fastest = f;
149 }
150
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
151 printk(KERN_INFO "xor: using function: %s (%d.%03d MB/sec)\n",
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
152 fastest->name, fastest->speed / 1000, fastest->speed % 1000);
153
154 #undef xor_speed
155
d788fec crypto, xor: Sanitize checksumming function selection output
Borislav Petkov authored
156 out:
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
157 free_pages((unsigned long)b1, 2);
158
159 active_template = fastest;
160 return 0;
161 }
162
163 static __exit void xor_exit(void) { }
164
165 MODULE_LICENSE("GPL");
166
685784a @djbw xor: make 'xor_blocks' a library routine for use with async_tx
djbw authored
167 /* when built-in xor.o must initialize before drivers/md/md.o */
168 core_initcall(calibrate_xor_blocks);
1da177e Linux-2.6.12-rc2
Linus Torvalds authored
169 module_exit(xor_exit);
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