tools: Adopt roundup_pow_of_two
authorArnaldo Carvalho de Melo <acme@redhat.com>
Tue, 16 Dec 2014 16:19:23 +0000 (13:19 -0300)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Wed, 17 Dec 2014 14:58:15 +0000 (11:58 -0300)
To replace equivalent code used in the mmap_pages command line
parameter handling in tools/perf.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-i44zs02xt4zexfxywpklo7km@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/include/linux/log2.h

index 990b138..4144666 100644 (file)
@@ -48,6 +48,15 @@ bool is_power_of_2(unsigned long n)
 }
 
 /*
+ * round up to nearest power of two
+ */
+static inline __attribute__((const))
+unsigned long __roundup_pow_of_two(unsigned long n)
+{
+       return 1UL << fls_long(n - 1);
+}
+
+/*
  * round down to nearest power of two
  */
 static inline __attribute__((const))
@@ -141,6 +150,22 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
        __ilog2_u64(n)                          \
  )
 
+/**
+ * roundup_pow_of_two - round the given value up to nearest power of two
+ * @n - parameter
+ *
+ * round the given value up to the nearest power of two
+ * - the result is undefined when n == 0
+ * - this can be used to initialise global variables from constant data
+ */
+#define roundup_pow_of_two(n)                  \
+(                                              \
+       __builtin_constant_p(n) ? (             \
+               (n == 1) ? 1 :                  \
+               (1UL << (ilog2((n) - 1) + 1))   \
+                                  ) :          \
+       __roundup_pow_of_two(n)                 \
+ )
 
 /**
  * rounddown_pow_of_two - round the given value down to nearest power of two