diff options
Diffstat (limited to 'crypto/xor.c')
-rw-r--r-- | crypto/xor.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/crypto/xor.c b/crypto/xor.c new file mode 100644 index 000000000000..8281ac5e68a8 --- /dev/null +++ b/crypto/xor.c | |||
@@ -0,0 +1,156 @@ | |||
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> | ||
21 | #include <linux/raid/md.h> | ||
22 | #include <linux/raid/xor.h> | ||
23 | #include <asm/xor.h> | ||
24 | |||
25 | /* The xor routines to use. */ | ||
26 | static struct xor_block_template *active_template; | ||
27 | |||
28 | void | ||
29 | xor_blocks(unsigned int count, unsigned int bytes, void **ptr) | ||
30 | { | ||
31 | unsigned long *p0, *p1, *p2, *p3, *p4; | ||
32 | |||
33 | p0 = (unsigned long *) ptr[0]; | ||
34 | p1 = (unsigned long *) ptr[1]; | ||
35 | if (count == 2) { | ||
36 | active_template->do_2(bytes, p0, p1); | ||
37 | return; | ||
38 | } | ||
39 | |||
40 | p2 = (unsigned long *) ptr[2]; | ||
41 | if (count == 3) { | ||
42 | active_template->do_3(bytes, p0, p1, p2); | ||
43 | return; | ||
44 | } | ||
45 | |||
46 | p3 = (unsigned long *) ptr[3]; | ||
47 | if (count == 4) { | ||
48 | active_template->do_4(bytes, p0, p1, p2, p3); | ||
49 | return; | ||
50 | } | ||
51 | |||
52 | p4 = (unsigned long *) ptr[4]; | ||
53 | active_template->do_5(bytes, p0, p1, p2, p3, p4); | ||
54 | } | ||
55 | EXPORT_SYMBOL(xor_blocks); | ||
56 | |||
57 | /* Set of all registered templates. */ | ||
58 | static struct xor_block_template *template_list; | ||
59 | |||
60 | #define BENCH_SIZE (PAGE_SIZE) | ||
61 | |||
62 | static void | ||
63 | do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2) | ||
64 | { | ||
65 | int speed; | ||
66 | unsigned long now; | ||
67 | int i, count, max; | ||
68 | |||
69 | tmpl->next = template_list; | ||
70 | template_list = tmpl; | ||
71 | |||
72 | /* | ||
73 | * Count the number of XORs done during a whole jiffy, and use | ||
74 | * this to calculate the speed of checksumming. We use a 2-page | ||
75 | * allocation to have guaranteed color L1-cache layout. | ||
76 | */ | ||
77 | max = 0; | ||
78 | for (i = 0; i < 5; i++) { | ||
79 | now = jiffies; | ||
80 | count = 0; | ||
81 | while (jiffies == now) { | ||
82 | mb(); /* prevent loop optimzation */ | ||
83 | tmpl->do_2(BENCH_SIZE, b1, b2); | ||
84 | mb(); | ||
85 | count++; | ||
86 | mb(); | ||
87 | } | ||
88 | if (count > max) | ||
89 | max = count; | ||
90 | } | ||
91 | |||
92 | speed = max * (HZ * BENCH_SIZE / 1024); | ||
93 | tmpl->speed = speed; | ||
94 | |||
95 | printk(KERN_INFO " %-10s: %5d.%03d MB/sec\n", tmpl->name, | ||
96 | speed / 1000, speed % 1000); | ||
97 | } | ||
98 | |||
99 | static int __init | ||
100 | calibrate_xor_blocks(void) | ||
101 | { | ||
102 | void *b1, *b2; | ||
103 | struct xor_block_template *f, *fastest; | ||
104 | |||
105 | b1 = (void *) __get_free_pages(GFP_KERNEL, 2); | ||
106 | if (!b1) { | ||
107 | printk(KERN_WARNING "xor: Yikes! No memory available.\n"); | ||
108 | return -ENOMEM; | ||
109 | } | ||
110 | b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE; | ||
111 | |||
112 | /* | ||
113 | * If this arch/cpu has a short-circuited selection, don't loop through | ||
114 | * all the possible functions, just test the best one | ||
115 | */ | ||
116 | |||
117 | fastest = NULL; | ||
118 | |||
119 | #ifdef XOR_SELECT_TEMPLATE | ||
120 | fastest = XOR_SELECT_TEMPLATE(fastest); | ||
121 | #endif | ||
122 | |||
123 | #define xor_speed(templ) do_xor_speed((templ), b1, b2) | ||
124 | |||
125 | if (fastest) { | ||
126 | printk(KERN_INFO "xor: automatically using best " | ||
127 | "checksumming function: %s\n", | ||
128 | fastest->name); | ||
129 | xor_speed(fastest); | ||
130 | } else { | ||
131 | printk(KERN_INFO "xor: measuring checksumming speed\n"); | ||
132 | XOR_TRY_TEMPLATES; | ||
133 | fastest = template_list; | ||
134 | for (f = fastest; f; f = f->next) | ||
135 | if (f->speed > fastest->speed) | ||
136 | fastest = f; | ||
137 | } | ||
138 | |||
139 | printk(KERN_INFO "xor: using function: %s (%d.%03d MB/sec)\n", | ||
140 | fastest->name, fastest->speed / 1000, fastest->speed % 1000); | ||
141 | |||
142 | #undef xor_speed | ||
143 | |||
144 | free_pages((unsigned long)b1, 2); | ||
145 | |||
146 | active_template = fastest; | ||
147 | return 0; | ||
148 | } | ||
149 | |||
150 | static __exit void xor_exit(void) { } | ||
151 | |||
152 | MODULE_LICENSE("GPL"); | ||
153 | |||
154 | /* when built-in xor.o must initialize before drivers/md/md.o */ | ||
155 | core_initcall(calibrate_xor_blocks); | ||
156 | module_exit(xor_exit); | ||