https://github.com/torvalds/linux
Revision ea0854170c95245a258b386c7a9314399c949fe0 authored by Shaohui Zheng on 02 February 2010, 21:44:16 UTC, committed by Linus Torvalds on 03 February 2010, 02:11:23 UTC
Newly added memory can not be accessed via /dev/mem, because we do not update the variables high_memory, max_pfn and max_low_pfn. Add a function update_end_of_memory_vars() to update these variables for 64-bit kernels. [akpm@linux-foundation.org: simplify comment] Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Li Haicheng <haicheng.li@intel.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent a225a5c
Tip revision: ea0854170c95245a258b386c7a9314399c949fe0 authored by Shaohui Zheng on 02 February 2010, 21:44:16 UTC
memory hotplug: fix a bug on /dev/mem for 64-bit kernels
memory hotplug: fix a bug on /dev/mem for 64-bit kernels
Tip revision: ea08541
find_last_bit.c
/* find_last_bit.c: fallback find next bit implementation
*
* Copyright (C) 2008 IBM Corporation
* Written by Rusty Russell <rusty@rustcorp.com.au>
* (Inspired by David Howell's find_next_bit implementation)
*
* 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 of the License, or (at your option) any later version.
*/
#include <linux/bitops.h>
#include <linux/module.h>
#include <asm/types.h>
#include <asm/byteorder.h>
unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
{
unsigned long words;
unsigned long tmp;
/* Start at final word. */
words = size / BITS_PER_LONG;
/* Partial final word? */
if (size & (BITS_PER_LONG-1)) {
tmp = (addr[words] & (~0UL >> (BITS_PER_LONG
- (size & (BITS_PER_LONG-1)))));
if (tmp)
goto found;
}
while (words) {
tmp = addr[--words];
if (tmp) {
found:
return words * BITS_PER_LONG + __fls(tmp);
}
}
/* Not found */
return size;
}
EXPORT_SYMBOL(find_last_bit);
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