diff options
| -rw-r--r-- | arch/x86/include/asm/hash.h | 51 | ||||
| -rw-r--r-- | arch/x86/lib/hash.c | 29 | ||||
| -rw-r--r-- | include/asm-generic/hash.h | 36 | ||||
| -rw-r--r-- | include/linux/hash.h | 34 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/hash.c | 39 |
6 files changed, 93 insertions, 98 deletions
diff --git a/arch/x86/include/asm/hash.h b/arch/x86/include/asm/hash.h index a881d784f044..e8c58f88b1d4 100644 --- a/arch/x86/include/asm/hash.h +++ b/arch/x86/include/asm/hash.h @@ -1,48 +1,7 @@ -#ifndef __ASM_X86_HASH_H -#define __ASM_X86_HASH_H +#ifndef _ASM_X86_HASH_H +#define _ASM_X86_HASH_H -#include <linux/cpufeature.h> -#include <asm/alternative.h> +struct fast_hash_ops; +extern void setup_arch_fast_hash(struct fast_hash_ops *ops); -u32 __intel_crc4_2_hash(const void *data, u32 len, u32 seed); -u32 __intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed); - -/* - * non-inline versions of jhash so gcc does not need to generate - * duplicate code in every object file - */ -u32 __jhash(const void *data, u32 len, u32 seed); -u32 __jhash2(const u32 *data, u32 len, u32 seed); - -/* - * for documentation of these functions please look into - * <include/asm-generic/hash.h> - */ - -static inline u32 arch_fast_hash(const void *data, u32 len, u32 seed) -{ - u32 hash; - - alternative_call(__jhash, __intel_crc4_2_hash, X86_FEATURE_XMM4_2, -#ifdef CONFIG_X86_64 - "=a" (hash), "D" (data), "S" (len), "d" (seed)); -#else - "=a" (hash), "a" (data), "d" (len), "c" (seed)); -#endif - return hash; -} - -static inline u32 arch_fast_hash2(const u32 *data, u32 len, u32 seed) -{ - u32 hash; - - alternative_call(__jhash2, __intel_crc4_2_hash2, X86_FEATURE_XMM4_2, -#ifdef CONFIG_X86_64 - "=a" (hash), "D" (data), "S" (len), "d" (seed)); -#else - "=a" (hash), "a" (data), "d" (len), "c" (seed)); -#endif - return hash; -} - -#endif /* __ASM_X86_HASH_H */ +#endif /* _ASM_X86_HASH_H */ diff --git a/arch/x86/lib/hash.c b/arch/x86/lib/hash.c index e14327198835..ff4fa51a5b1f 100644 --- a/arch/x86/lib/hash.c +++ b/arch/x86/lib/hash.c @@ -31,13 +31,13 @@ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ +#include <linux/hash.h> +#include <linux/init.h> + #include <asm/processor.h> #include <asm/cpufeature.h> #include <asm/hash.h> -#include <linux/hash.h> -#include <linux/jhash.h> - static inline u32 crc32_u32(u32 crc, u32 val) { #ifdef CONFIG_AS_CRC32 @@ -48,7 +48,7 @@ static inline u32 crc32_u32(u32 crc, u32 val) return crc; } -u32 __intel_crc4_2_hash(const void *data, u32 len, u32 seed) +static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed) { const u32 *p32 = (const u32 *) data; u32 i, tmp = 0; @@ -71,27 +71,22 @@ u32 __intel_crc4_2_hash(const void *data, u32 len, u32 seed) return seed; } -EXPORT_SYMBOL(__intel_crc4_2_hash); -u32 __intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed) +static u32 intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed) { + const u32 *p32 = (const u32 *) data; u32 i; for (i = 0; i < len; i++) - seed = crc32_u32(seed, *data++); + seed = crc32_u32(seed, *p32++); return seed; } -EXPORT_SYMBOL(__intel_crc4_2_hash2); -u32 __jhash(const void *data, u32 len, u32 seed) +void __init setup_arch_fast_hash(struct fast_hash_ops *ops) { - return jhash(data, len, seed); -} -EXPORT_SYMBOL(__jhash); - -u32 __jhash2(const u32 *data, u32 len, u32 seed) -{ - return jhash2(data, len, seed); + if (cpu_has_xmm4_2) { + ops->hash = intel_crc4_2_hash; + ops->hash2 = intel_crc4_2_hash2; + } } -EXPORT_SYMBOL(__jhash2); diff --git a/include/asm-generic/hash.h b/include/asm-generic/hash.h index 3c82760ff2a4..b6312843dbd9 100644 --- a/include/asm-generic/hash.h +++ b/include/asm-generic/hash.h @@ -1,41 +1,9 @@ #ifndef __ASM_GENERIC_HASH_H #define __ASM_GENERIC_HASH_H -#include <linux/jhash.h> - -/** - * arch_fast_hash - Caclulates a hash over a given buffer that can have - * arbitrary size. This function will eventually use an - * architecture-optimized hashing implementation if - * available, and trades off distribution for speed. - * - * @data: buffer to hash - * @len: length of buffer in bytes - * @seed: start seed - * - * Returns 32bit hash. - */ -static inline u32 arch_fast_hash(const void *data, u32 len, u32 seed) -{ - return jhash(data, len, seed); -} - -/** - * arch_fast_hash2 - Caclulates a hash over a given buffer that has a - * size that is of a multiple of 32bit words. This - * function will eventually use an architecture- - * optimized hashing implementation if available, - * and trades off distribution for speed. - * - * @data: buffer to hash (must be 32bit padded) - * @len: number of 32bit words - * @seed: start seed - * - * Returns 32bit hash. - */ -static inline u32 arch_fast_hash2(const u32 *data, u32 len, u32 seed) +struct fast_hash_ops; +static inline void setup_arch_fast_hash(struct fast_hash_ops *ops) { - return jhash2(data, len, seed); } #endif /* __ASM_GENERIC_HASH_H */ diff --git a/include/linux/hash.h b/include/linux/hash.h index 6e8fb028848c..d0494c399392 100644 --- a/include/linux/hash.h +++ b/include/linux/hash.h @@ -84,4 +84,38 @@ static inline u32 hash32_ptr(const void *ptr) return (u32)val; } +struct fast_hash_ops { + u32 (*hash)(const void *data, u32 len, u32 seed); + u32 (*hash2)(const u32 *data, u32 len, u32 seed); +}; + +/** + * arch_fast_hash - Caclulates a hash over a given buffer that can have + * arbitrary size. This function will eventually use an + * architecture-optimized hashing implementation if + * available, and trades off distribution for speed. + * + * @data: buffer to hash + * @len: length of buffer in bytes + * @seed: start seed + * + * Returns 32bit hash. + */ +extern u32 arch_fast_hash(const void *data, u32 len, u32 seed); + +/** + * arch_fast_hash2 - Caclulates a hash over a given buffer that has a + * size that is of a multiple of 32bit words. This + * function will eventually use an architecture- + * optimized hashing implementation if available, + * and trades off distribution for speed. + * + * @data: buffer to hash (must be 32bit padded) + * @len: number of 32bit words + * @seed: start seed + * + * Returns 32bit hash. + */ +extern u32 arch_fast_hash2(const u32 *data, u32 len, u32 seed); + #endif /* _LINUX_HASH_H */ diff --git a/lib/Makefile b/lib/Makefile index 04e53dd16070..7512dc978f18 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -26,7 +26,7 @@ obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o clz_ctz.o \ bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o \ - percpu-refcount.o percpu_ida.o rhashtable.o + percpu-refcount.o percpu_ida.o hash.o rhashtable.o obj-y += string_helpers.o obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o obj-y += kstrtox.o diff --git a/lib/hash.c b/lib/hash.c new file mode 100644 index 000000000000..fea973f4bd57 --- /dev/null +++ b/lib/hash.c @@ -0,0 +1,39 @@ +/* General purpose hashing library + * + * That's a start of a kernel hashing library, which can be extended + * with further algorithms in future. arch_fast_hash{2,}() will + * eventually resolve to an architecture optimized implementation. + * + * Copyright 2013 Francesco Fusco <ffusco@redhat.com> + * Copyright 2013 Daniel Borkmann <dborkman@redhat.com> + * Copyright 2013 Thomas Graf <tgraf@redhat.com> + * Licensed under the GNU General Public License, version 2.0 (GPLv2) + */ + +#include <linux/jhash.h> +#include <linux/hash.h> +#include <linux/cache.h> + +static struct fast_hash_ops arch_hash_ops __read_mostly = { + .hash = jhash, + .hash2 = jhash2, +}; + +u32 arch_fast_hash(const void *data, u32 len, u32 seed) +{ + return arch_hash_ops.hash(data, len, seed); +} +EXPORT_SYMBOL_GPL(arch_fast_hash); + +u32 arch_fast_hash2(const u32 *data, u32 len, u32 seed) +{ + return arch_hash_ops.hash2(data, len, seed); +} +EXPORT_SYMBOL_GPL(arch_fast_hash2); + +static int __init hashlib_init(void) +{ + setup_arch_fast_hash(&arch_hash_ops); + return 0; +} +early_initcall(hashlib_init); |