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author | Yalin Wang <Yalin.Wang@sonymobile.com> | 2014-11-03 03:01:03 +0100 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2014-12-22 16:43:06 +0000 |
commit | 556d2f055bf6d79ce81587dfe774d4dd10da473f (patch) | |
tree | 3b1eaeda540d1592936691f953607a377668f90f /lib/bitrev.c | |
parent | 97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff) | |
download | lwn-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.c | 17 |
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 */ |