Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/asm changes from Ingo Molnar

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Include probe_roms.h in probe_roms.c
  x86/32: Print control and debug registers for kerenel context
  x86: Tighten dependencies of CPU_SUP_*_32
  x86/numa: Improve internode cache alignment
  x86: Fix the NMI nesting comments
  x86-64: Improve insn scheduling in SAVE_ARGS_IRQ
  x86-64: Fix CFI annotations for NMI nesting code
  bitops: Add missing parentheses to new get_order macro
  bitops: Optimise get_order()
  bitops: Adjust the comment on get_order() to describe the size==0 case
  x86/spinlocks: Eliminate TICKET_MASK
  x86-64: Handle byte-wise tail copying in memcpy() without a loop
  x86-64: Fix memcpy() to support sizes of 4Gb and above
  x86-64: Fix memset() to support sizes of 4Gb and above
  x86-64: Slightly shorten copy_page()

1 files changed, 45 insertions, 8 deletions

diff --git a/include/asm-generic/getorder.h b/include/asm-generic/getorder.h
index 67e7245dc9b3..65e4468ac53d 100644
--- a/include/asm-generic/getorder.h
+++ b/include/asm-generic/getorder.h
@@ -4,21 +4,58 @@
 #ifndef __ASSEMBLY__
 
 #include <linux/compiler.h>
+#include <linux/log2.h>
 
-/* Pure 2^n version of get_order */
-static inline __attribute_const__ int get_order(unsigned long size)
+/*
+ * Runtime evaluation 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);
+	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 */