linux-stable/crypto/xor.c
Linus Torvalds c80ddb5263 md updates for 3.5
Main features:
  - RAID10 arrays can be reshapes - adding and removing devices and
    changing chunks (not 'far' array though)
  - allow RAID5 arrays to be reshaped with a backup file (not tested
    yet, but the priciple works fine for RAID10).
  - arrays can be reshaped while a bitmap is present - you no longer
    need to remove it first
  - SSSE3 support for RAID6 syndrome calculations
 
 and of course a number of minor fixes etc.
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Merge tag 'md-3.5' of git://neil.brown.name/md

Pull md updates from NeilBrown:
 "It's been a busy cycle for md - lots of fun stuff here..  if you like
  this kind of thing :-)

  Main features:
   - RAID10 arrays can be reshaped - adding and removing devices and
     changing chunks (not 'far' array though)
   - allow RAID5 arrays to be reshaped with a backup file (not tested
     yet, but the priciple works fine for RAID10).
   - arrays can be reshaped while a bitmap is present - you no longer
     need to remove it first
   - SSSE3 support for RAID6 syndrome calculations

  and of course a number of minor fixes etc."

* tag 'md-3.5' of git://neil.brown.name/md: (56 commits)
  md/bitmap: record the space available for the bitmap in the superblock.
  md/raid10: Remove extras after reshape to smaller number of devices.
  md/raid5: improve removal of extra devices after reshape.
  md: check the return of mddev_find()
  MD RAID1: Further conditionalize 'fullsync'
  DM RAID: Use md_error() in place of simply setting Faulty bit
  DM RAID: Record and handle missing devices
  DM RAID: Set recovery flags on resume
  md/raid5: Allow reshape while a bitmap is present.
  md/raid10: resize bitmap when required during reshape.
  md: allow array to be resized while bitmap is present.
  md/bitmap: make sure reshape request are reflected in superblock.
  md/bitmap: add bitmap_resize function to allow bitmap resizing.
  md/bitmap: use DIV_ROUND_UP instead of open-code
  md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'
  md/bitmap: make bitmap bitops atomic.
  md/bitmap: make _page_attr bitops atomic.
  md/bitmap: merge bitmap_file_unmap and bitmap_file_put.
  md/bitmap: remove async freeing of bitmap file.
  md/bitmap: convert some spin_lock_irqsave to spin_lock_irq
  ...
2012-05-23 17:08:40 -07:00

169 lines
4 KiB
C

/*
* xor.c : Multiple Devices driver for Linux
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000,
* Ingo Molnar, Matti Aarnio, Jakub Jelinek, Richard Henderson.
*
* Dispatch optimized RAID-5 checksumming functions.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* You should have received a copy of the GNU General Public License
* (for example /usr/src/linux/COPYING); if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define BH_TRACE 0
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/raid/xor.h>
#include <linux/jiffies.h>
#include <linux/preempt.h>
#include <asm/xor.h>
/* The xor routines to use. */
static struct xor_block_template *active_template;
void
xor_blocks(unsigned int src_count, unsigned int bytes, void *dest, void **srcs)
{
unsigned long *p1, *p2, *p3, *p4;
p1 = (unsigned long *) srcs[0];
if (src_count == 1) {
active_template->do_2(bytes, dest, p1);
return;
}
p2 = (unsigned long *) srcs[1];
if (src_count == 2) {
active_template->do_3(bytes, dest, p1, p2);
return;
}
p3 = (unsigned long *) srcs[2];
if (src_count == 3) {
active_template->do_4(bytes, dest, p1, p2, p3);
return;
}
p4 = (unsigned long *) srcs[3];
active_template->do_5(bytes, dest, p1, p2, p3, p4);
}
EXPORT_SYMBOL(xor_blocks);
/* Set of all registered templates. */
static struct xor_block_template *template_list;
#define BENCH_SIZE (PAGE_SIZE)
static void
do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2)
{
int speed;
unsigned long now, j;
int i, count, max;
tmpl->next = template_list;
template_list = tmpl;
preempt_disable();
/*
* Count the number of XORs done during a whole jiffy, and use
* this to calculate the speed of checksumming. We use a 2-page
* allocation to have guaranteed color L1-cache layout.
*/
max = 0;
for (i = 0; i < 5; i++) {
j = jiffies;
count = 0;
while ((now = jiffies) == j)
cpu_relax();
while (time_before(jiffies, now + 1)) {
mb(); /* prevent loop optimzation */
tmpl->do_2(BENCH_SIZE, b1, b2);
mb();
count++;
mb();
}
if (count > max)
max = count;
}
preempt_enable();
speed = max * (HZ * BENCH_SIZE / 1024);
tmpl->speed = speed;
printk(KERN_INFO " %-10s: %5d.%03d MB/sec\n", tmpl->name,
speed / 1000, speed % 1000);
}
static int __init
calibrate_xor_blocks(void)
{
void *b1, *b2;
struct xor_block_template *f, *fastest;
/*
* Note: Since the memory is not actually used for _anything_ but to
* test the XOR speed, we don't really want kmemcheck to warn about
* reading uninitialized bytes here.
*/
b1 = (void *) __get_free_pages(GFP_KERNEL | __GFP_NOTRACK, 2);
if (!b1) {
printk(KERN_WARNING "xor: Yikes! No memory available.\n");
return -ENOMEM;
}
b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
/*
* If this arch/cpu has a short-circuited selection, don't loop through
* all the possible functions, just test the best one
*/
fastest = NULL;
#ifdef XOR_SELECT_TEMPLATE
fastest = XOR_SELECT_TEMPLATE(fastest);
#endif
#define xor_speed(templ) do_xor_speed((templ), b1, b2)
if (fastest) {
printk(KERN_INFO "xor: automatically using best "
"checksumming function:\n");
xor_speed(fastest);
goto out;
} else {
printk(KERN_INFO "xor: measuring software checksum speed\n");
XOR_TRY_TEMPLATES;
fastest = template_list;
for (f = fastest; f; f = f->next)
if (f->speed > fastest->speed)
fastest = f;
}
printk(KERN_INFO "xor: using function: %s (%d.%03d MB/sec)\n",
fastest->name, fastest->speed / 1000, fastest->speed % 1000);
#undef xor_speed
out:
free_pages((unsigned long)b1, 2);
active_template = fastest;
return 0;
}
static __exit void xor_exit(void) { }
MODULE_LICENSE("GPL");
/* when built-in xor.o must initialize before drivers/md/md.o */
core_initcall(calibrate_xor_blocks);
module_exit(xor_exit);