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authorYalin Wang <Yalin.Wang@sonymobile.com>2014-11-03 03:01:03 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-12-22 16:43:06 +0000
commit556d2f055bf6d79ce81587dfe774d4dd10da473f (patch)
tree3b1eaeda540d1592936691f953607a377668f90f /lib/bitrev.c
parent97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff)
downloadlwn-556d2f055bf6d79ce81587dfe774d4dd10da473f.tar.gz
lwn-556d2f055bf6d79ce81587dfe774d4dd10da473f.zip
ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction
this change add CONFIG_HAVE_ARCH_BITREVERSE config option, so that we can use some architecture's bitrev hardware instruction to do bitrev operation. Introduce __constant_bitrev* macro for constant bitrev operation. Change __bitrev16() __bitrev32() to be inline function, don't need export symbol for these tiny functions. Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'lib/bitrev.c')
-rw-r--r--lib/bitrev.c17
1 files changed, 2 insertions, 15 deletions
diff --git a/lib/bitrev.c b/lib/bitrev.c
index 3956203456d4..40ffda94cc5d 100644
--- a/lib/bitrev.c
+++ b/lib/bitrev.c
@@ -1,3 +1,4 @@
+#ifndef CONFIG_HAVE_ARCH_BITREVERSE
#include <linux/types.h>
#include <linux/module.h>
#include <linux/bitrev.h>
@@ -42,18 +43,4 @@ const u8 byte_rev_table[256] = {
};
EXPORT_SYMBOL_GPL(byte_rev_table);
-u16 bitrev16(u16 x)
-{
- return (bitrev8(x & 0xff) << 8) | bitrev8(x >> 8);
-}
-EXPORT_SYMBOL(bitrev16);
-
-/**
- * bitrev32 - reverse the order of bits in a u32 value
- * @x: value to be bit-reversed
- */
-u32 bitrev32(u32 x)
-{
- return (bitrev16(x & 0xffff) << 16) | bitrev16(x >> 16);
-}
-EXPORT_SYMBOL(bitrev32);
+#endif /* CONFIG_HAVE_ARCH_BITREVERSE */