From ef55d53caa055aedee13e77da82740987dd64f2d Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 8 Dec 2006 02:37:53 -0800 Subject: [PATCH] [PATCH] LOG2: Provide ilog2() fallbacks for powerpc Provide ilog2() fallbacks for powerpc for 32-bit numbers and 64-bit numbers on ppc64. Signed-off-by: David Howells Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/powerpc/Kconfig | 4 ++-- include/asm-powerpc/bitops.h | 21 ++++++++++++++++++++- include/asm-powerpc/page_32.h | 10 +--------- 3 files changed, 23 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 97c7a212cdd..56c3c4065eb 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -43,11 +43,11 @@ config RWSEM_XCHGADD_ALGORITHM config ARCH_HAS_ILOG2_U32 bool - default n + default y config ARCH_HAS_ILOG2_U64 bool - default n + default y if 64BIT config GENERIC_HWEIGHT bool diff --git a/include/asm-powerpc/bitops.h b/include/asm-powerpc/bitops.h index c341063d080..0288144ea02 100644 --- a/include/asm-powerpc/bitops.h +++ b/include/asm-powerpc/bitops.h @@ -190,7 +190,8 @@ static __inline__ void set_bits(unsigned long mask, unsigned long *addr) * Return the zero-based bit position (LE, not IBM bit numbering) of * the most significant 1-bit in a double word. */ -static __inline__ int __ilog2(unsigned long x) +static __inline__ __attribute__((const)) +int __ilog2(unsigned long x) { int lz; @@ -198,6 +199,24 @@ static __inline__ int __ilog2(unsigned long x) return BITS_PER_LONG - 1 - lz; } +static inline __attribute__((const)) +int __ilog2_u32(u32 n) +{ + int bit; + asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n)); + return 31 - bit; +} + +#ifdef __powerpc64__ +static inline __attribute__((const)) +int __ilog2_u64(u32 n) +{ + int bit; + asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n)); + return 63 - bit; +} +#endif + /* * Determines the bit position of the least significant 0 bit in the * specified double word. The returned bit position will be diff --git a/include/asm-powerpc/page_32.h b/include/asm-powerpc/page_32.h index 2677bad70f4..07f6d3cf5e5 100644 --- a/include/asm-powerpc/page_32.h +++ b/include/asm-powerpc/page_32.h @@ -26,15 +26,7 @@ extern void clear_pages(void *page, int order); static inline void clear_page(void *page) { clear_pages(page, 0); } extern void copy_page(void *to, void *from); -/* Pure 2^n version of get_order */ -extern __inline__ int get_order(unsigned long size) -{ - int lz; - - size = (size-1) >> PAGE_SHIFT; - asm ("cntlzw %0,%1" : "=r" (lz) : "r" (size)); - return 32 - lz; -} +#include #endif /* __ASSEMBLY__ */ -- 2.41.1