aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2006-12-08 02:37:53 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-08 08:28:51 -0800
commitef55d53caa055aedee13e77da82740987dd64f2d (patch)
tree243bbfca98e504401ea563d6c799ed23c12c08b8
parent39d61db0edb34d60b83c5e0d62d0e906578cc707 (diff)
[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 <dhowells@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/powerpc/Kconfig4
-rw-r--r--include/asm-powerpc/bitops.h21
-rw-r--r--include/asm-powerpc/page_32.h10
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 <asm-generic/page.h>
#endif /* __ASSEMBLY__ */