linux/include/asm-generic/getorder.h
Joerg Roedel b893485db9 bitops: Add missing parentheses to new get_order macro
The new get_order macro introcuded in commit

	d66acc39c7

does not use parentheses around all uses of the parameter n.
This causes new compile warnings, for example in the
amd_iommu_init.c function:

drivers/iommu/amd_iommu_init.c:561:6: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses]
drivers/iommu/amd_iommu_init.c:561:6: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses]

Fix those warnings by adding the missing parentheses.

Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/r/1330088295-28732-1-git-send-email-joerg.roedel@amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-02-24 10:39:27 -08:00

62 lines
1.4 KiB
C

#ifndef __ASM_GENERIC_GETORDER_H
#define __ASM_GENERIC_GETORDER_H
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <linux/log2.h>
/*
* Runtime evaluation of get_order()
*/
static inline __attribute_const__
int __get_order(unsigned long size)
{
int order;
size--;
size >>= PAGE_SHIFT;
#if BITS_PER_LONG == 32
order = fls(size);
#else
order = fls64(size);
#endif
return order;
}
/**
* get_order - Determine the allocation order of a memory size
* @size: The size for which to get the order
*
* Determine the allocation order of a particular sized block of memory. This
* is on a logarithmic scale, where:
*
* 0 -> 2^0 * PAGE_SIZE and below
* 1 -> 2^1 * PAGE_SIZE to 2^0 * PAGE_SIZE + 1
* 2 -> 2^2 * PAGE_SIZE to 2^1 * PAGE_SIZE + 1
* 3 -> 2^3 * PAGE_SIZE to 2^2 * PAGE_SIZE + 1
* 4 -> 2^4 * PAGE_SIZE to 2^3 * PAGE_SIZE + 1
* ...
*
* The order returned is used to find the smallest allocation granule required
* to hold an object of the specified size.
*
* The result is undefined if the size is 0.
*
* This function may be used to initialise variables with compile time
* evaluations of constants.
*/
#define get_order(n) \
( \
__builtin_constant_p(n) ? ( \
((n) == 0UL) ? BITS_PER_LONG - PAGE_SHIFT : \
(((n) < (1UL << PAGE_SHIFT)) ? 0 : \
ilog2((n) - 1) - PAGE_SHIFT + 1) \
) : \
__get_order(n) \
)
#endif /* __ASSEMBLY__ */
#endif /* __ASM_GENERIC_GETORDER_H */