[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>

1 files changed, 26 insertions, 0 deletions

diff --git a/include/asm-generic/page.h b/include/asm-generic/page.h
new file mode 100644
index 000000000000..a96b5d986b6e
--- /dev/null
+++ b/include/asm-generic/page.h
@@ -0,0 +1,26 @@
+#ifndef _ASM_GENERIC_PAGE_H
+#define _ASM_GENERIC_PAGE_H
+
+#ifdef __KERNEL__
+#ifndef __ASSEMBLY__
+
+#include <linux/compiler.h>
+
+/* Pure 2^n version of get_order */
+static __inline__ __attribute_const__ int get_order(unsigned long size)
+{
+        int order;
+
+        size = (size - 1) >> (PAGE_SHIFT - 1);
+        order = -1;
+        do {
+                size >>= 1;
+                order++;
+        } while (size);
+        return order;
+}
+
+#endif  /* __ASSEMBLY__ */
+#endif  /* __KERNEL__ */
+
+#endif  /* _ASM_GENERIC_PAGE_H */