From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001 From: Srikant Patnaik Date: Sun, 11 Jan 2015 12:28:04 +0530 Subject: Moved, renamed, and deleted files The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure. --- include/asm-generic/getorder.h | 61 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 include/asm-generic/getorder.h (limited to 'include/asm-generic/getorder.h') diff --git a/include/asm-generic/getorder.h b/include/asm-generic/getorder.h new file mode 100644 index 00000000..65e4468a --- /dev/null +++ b/include/asm-generic/getorder.h @@ -0,0 +1,61 @@ +#ifndef __ASM_GENERIC_GETORDER_H +#define __ASM_GENERIC_GETORDER_H + +#ifndef __ASSEMBLY__ + +#include +#include + +/* + * 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 */ -- cgit