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linux/include/asm-generic/page.h

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[PATCH] mm: consolidate get_order Someone mentioned that almost all the architectures used basically the same implementation of get_order. This patch consolidates them into asm-generic/page.h and includes that in the appropriate places. The exceptions are ia64 and ppc which have their own (presumably optimised) versions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-04 06:54:30 +08:00
#ifndef _ASM_GENERIC_PAGE_H
#define _ASM_GENERIC_PAGE_H
#ifndef __ASSEMBLY__
Revert "[PATCH] LOG2: Alter get_order() so that it can make use of ilog2() on a constant" This reverts commit 39d61db0edb34d60b83c5e0d62d0e906578cc707. The commit was buggy in multiple ways: - the conversion to ilog2() was incorrect to begin with - it tested the wrong #defines, so on all architectures but FRV you'd never see the bug except for constant arguments. - the new "get_order()" macro used its arguments multiple times, and didn't even parenthesize them properly - despite the comments, it was not true that you could use it for constant initializers, since not all architectures even use the generic page.h header file. All of the problems are individually fixable, but it all boils down to: better just revert it, and re-do it from scratch. Cc: David Howells <dhowells@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-07 11:38:01 +08:00
#include <linux/compiler.h>
[PATCH] mm: consolidate get_order Someone mentioned that almost all the architectures used basically the same implementation of get_order. This patch consolidates them into asm-generic/page.h and includes that in the appropriate places. The exceptions are ia64 and ppc which have their own (presumably optimised) versions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-04 06:54:30 +08:00
Revert "[PATCH] LOG2: Alter get_order() so that it can make use of ilog2() on a constant" This reverts commit 39d61db0edb34d60b83c5e0d62d0e906578cc707. The commit was buggy in multiple ways: - the conversion to ilog2() was incorrect to begin with - it tested the wrong #defines, so on all architectures but FRV you'd never see the bug except for constant arguments. - the new "get_order()" macro used its arguments multiple times, and didn't even parenthesize them properly - despite the comments, it was not true that you could use it for constant initializers, since not all architectures even use the generic page.h header file. All of the problems are individually fixable, but it all boils down to: better just revert it, and re-do it from scratch. Cc: David Howells <dhowells@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-07 11:38:01 +08:00
/* Pure 2^n version of get_order */
static __inline__ __attribute_const__ int get_order(unsigned long size)
[PATCH] mm: consolidate get_order Someone mentioned that almost all the architectures used basically the same implementation of get_order. This patch consolidates them into asm-generic/page.h and includes that in the appropriate places. The exceptions are ia64 and ppc which have their own (presumably optimised) versions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-04 06:54:30 +08:00
{
int order;
Revert "[PATCH] LOG2: Alter get_order() so that it can make use of ilog2() on a constant" This reverts commit 39d61db0edb34d60b83c5e0d62d0e906578cc707. The commit was buggy in multiple ways: - the conversion to ilog2() was incorrect to begin with - it tested the wrong #defines, so on all architectures but FRV you'd never see the bug except for constant arguments. - the new "get_order()" macro used its arguments multiple times, and didn't even parenthesize them properly - despite the comments, it was not true that you could use it for constant initializers, since not all architectures even use the generic page.h header file. All of the problems are individually fixable, but it all boils down to: better just revert it, and re-do it from scratch. Cc: David Howells <dhowells@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-07 11:38:01 +08:00
size = (size - 1) >> (PAGE_SHIFT - 1);
[PATCH] mm: consolidate get_order Someone mentioned that almost all the architectures used basically the same implementation of get_order. This patch consolidates them into asm-generic/page.h and includes that in the appropriate places. The exceptions are ia64 and ppc which have their own (presumably optimised) versions. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-04 06:54:30 +08:00
order = -1;
do {
size >>= 1;
order++;
} while (size);
return order;
}
#endif /* __ASSEMBLY__ */
#endif /* _ASM_GENERIC_PAGE_H */