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authorDan Williams <dan.j.williams@intel.com>2007-07-09 14:56:42 -0400
committerDan Williams <dan.j.williams@intel.com>2007-07-13 11:06:14 -0400
commit685784aaf3cd0e3ff5e36c7ecf6f441cdbf57f73 (patch)
tree10f99829f7d877b87614fe69be77e363c026a8d7 /drivers/md/xor.c
parentd379b01e9087a582d58f4b678208a4f8d8376fe7 (diff)
xor: make 'xor_blocks' a library routine for use with async_tx
The async_tx api tries to use a dma engine for an operation, but will fall back to an optimized software routine otherwise. Xor support is implemented using the raid5 xor routines. For organizational purposes this routine is moved to a common area. The following fixes are also made: * rename xor_block => xor_blocks, suggested by Adrian Bunk * ensure that xor.o initializes before md.o in the built-in case * checkpatch.pl fixes * mark calibrate_xor_blocks __init, Adrian Bunk Cc: Adrian Bunk <bunk@stusta.de> Cc: NeilBrown <neilb@suse.de> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/md/xor.c')
-rw-r--r--drivers/md/xor.c154
1 files changed, 0 insertions, 154 deletions
diff --git a/drivers/md/xor.c b/drivers/md/xor.c
deleted file mode 100644
index 324897c4be4e..000000000000
--- a/drivers/md/xor.c
+++ /dev/null
@@ -1,154 +0,0 @@
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. */
26static struct xor_block_template *active_template;
27
28void
29xor_block(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
56/* Set of all registered templates. */
57static struct xor_block_template *template_list;
58
59#define BENCH_SIZE (PAGE_SIZE)
60
61static void
62do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
63{
64 int speed;
65 unsigned long now;
66 int i, count, max;
67
68 tmpl->next = template_list;
69 template_list = tmpl;
70
71 /*
72 * Count the number of XORs done during a whole jiffy, and use
73 * this to calculate the speed of checksumming. We use a 2-page
74 * allocation to have guaranteed color L1-cache layout.
75 */
76 max = 0;
77 for (i = 0; i < 5; i++) {
78 now = jiffies;
79 count = 0;
80 while (jiffies == now) {
81 mb();
82 tmpl->do_2(BENCH_SIZE, b1, b2);
83 mb();
84 count++;
85 mb();
86 }
87 if (count > max)
88 max = count;
89 }
90
91 speed = max * (HZ * BENCH_SIZE / 1024);
92 tmpl->speed = speed;
93
94 printk(" %-10s: %5d.%03d MB/sec\n", tmpl->name,
95 speed / 1000, speed % 1000);
96}
97
98static int
99calibrate_xor_block(void)
100{
101 void *b1, *b2;
102 struct xor_block_template *f, *fastest;
103
104 b1 = (void *) __get_free_pages(GFP_KERNEL, 2);
105 if (! b1) {
106 printk("raid5: Yikes! No memory available.\n");
107 return -ENOMEM;
108 }
109 b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
110
111 /*
112 * If this arch/cpu has a short-circuited selection, don't loop through all
113 * the possible functions, just test the best one
114 */
115
116 fastest = NULL;
117
118#ifdef XOR_SELECT_TEMPLATE
119 fastest = XOR_SELECT_TEMPLATE(fastest);
120#endif
121
122#define xor_speed(templ) do_xor_speed((templ), b1, b2)
123
124 if (fastest) {
125 printk(KERN_INFO "raid5: automatically using best checksumming function: %s\n",
126 fastest->name);
127 xor_speed(fastest);
128 } else {
129 printk(KERN_INFO "raid5: measuring checksumming speed\n");
130 XOR_TRY_TEMPLATES;
131 fastest = template_list;
132 for (f = fastest; f; f = f->next)
133 if (f->speed > fastest->speed)
134 fastest = f;
135 }
136
137 printk("raid5: using function: %s (%d.%03d MB/sec)\n",
138 fastest->name, fastest->speed / 1000, fastest->speed % 1000);
139
140#undef xor_speed
141
142 free_pages((unsigned long)b1, 2);
143
144 active_template = fastest;
145 return 0;
146}
147
148static __exit void xor_exit(void) { }
149
150EXPORT_SYMBOL(xor_block);
151MODULE_LICENSE("GPL");
152
153module_init(calibrate_xor_block);
154module_exit(xor_exit);