Commit d7e12014 authored by Ken Raeburn's avatar Ken Raeburn Committed by Mike Snitzer
Browse files

dm vdo murmurhash3: use kernel byteswapping routines instead of GCC ones 



Also open-code the calls.

Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarKen Raeburn <raeburn@redhat.com>
Signed-off-by: default avatarMatthew Sakai <msakai@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
parent 309d8ced

drivers/md/dm-vdo/murmurhash3.c

+8 −25
Original line number Diff line number Diff line
@@ -8,33 +8,14 @@ 


#include "murmurhash3.h"



#include <asm/unaligned.h>



static inline u64 rotl64(u64 x, s8 r)

{

	return (x << r) | (x >> (64 - r));

}



#define ROTL64(x, y) rotl64(x, y)

static __always_inline u64 getblock64(const u64 *p, int i)

{

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	return p[i];

#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

	return __builtin_bswap64(p[i]);

#else

#error "can't figure out byte order"

#endif

}



static __always_inline void putblock64(u64 *p, int i, u64 value)

{

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__

	p[i] = value;

#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

	p[i] = __builtin_bswap64(value);

#else

#error "can't figure out byte order"

#endif

}



/* Finalization mix - force all bits of a hash block to avalanche */
@@ -60,6 +41,8 @@ void murmurhash3_128(const void *key, const int len, const u32 seed, void *out) 
	const u64 c1 = 0x87c37b91114253d5LLU;

	const u64 c2 = 0x4cf5ad432745937fLLU;



	u64 *hash_out = out;



	/* body */



	const u64 *blocks = (const u64 *)(data);
@@ -67,8 +50,8 @@ void murmurhash3_128(const void *key, const int len, const u32 seed, void *out) 
	int i;



	for (i = 0; i < nblocks; i++) {

		u64 k1 = getblock64(blocks, i * 2 + 0);

		u64 k2 = getblock64(blocks, i * 2 + 1);

		u64 k1 = get_unaligned_le64(&blocks[i * 2]);

		u64 k2 = get_unaligned_le64(&blocks[i * 2 + 1]);



		k1 *= c1;

		k1 = ROTL64(k1, 31);
@@ -170,6 +153,6 @@ void murmurhash3_128(const void *key, const int len, const u32 seed, void *out) 
	h1 += h2;

	h2 += h1;



	putblock64((u64 *)out, 0, h1);

	putblock64((u64 *)out, 1, h2);

	put_unaligned_le64(h1, &hash_out[0]);

	put_unaligned_le64(h2, &hash_out[1]);

}