[linux.git] / lib / xxhash.c

/*
 * xxHash - Extremely Fast Hash algorithm
 * Copyright (C) 2012-2016, Yann Collet.
 *
 * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following disclaimer
 *     in the documentation and/or other materials provided with the
 *     distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License version 2 as published by the
 * Free Software Foundation. This program is dual-licensed; you may select
 * either version 2 of the GNU General Public License ("GPL") or BSD license
 * ("BSD").
 *
 * You can contact the author at:
 * - xxHash homepage: https://cyan4973.github.io/xxHash/
 * - xxHash source repository: https://github.com/Cyan4973/xxHash
 */

#include <asm/unaligned.h>
#include <linux/errno.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/xxhash.h>

/*-*************************************
 * Macros
 **************************************/
#define xxh_rotl32(x, r) ((x << r) | (x >> (32 - r)))
#define xxh_rotl64(x, r) ((x << r) | (x >> (64 - r)))

#ifdef __LITTLE_ENDIAN
# define XXH_CPU_LITTLE_ENDIAN 1
#else
# define XXH_CPU_LITTLE_ENDIAN 0
#endif

/*-*************************************
 * Constants
 **************************************/
static const uint32_t PRIME32_1 = 2654435761U;
static const uint32_t PRIME32_2 = 2246822519U;
static const uint32_t PRIME32_3 = 3266489917U;
static const uint32_t PRIME32_4 =  668265263U;
static const uint32_t PRIME32_5 =  374761393U;

static const uint64_t PRIME64_1 = 11400714785074694791ULL;
static const uint64_t PRIME64_2 = 14029467366897019727ULL;
static const uint64_t PRIME64_3 =  1609587929392839161ULL;
static const uint64_t PRIME64_4 =  9650029242287828579ULL;
static const uint64_t PRIME64_5 =  2870177450012600261ULL;

/*-**************************
 *  Utils
 ***************************/
void xxh32_copy_state(struct xxh32_state *dst, const struct xxh32_state *src)
{
	memcpy(dst, src, sizeof(*dst));
}
EXPORT_SYMBOL(xxh32_copy_state);

void xxh64_copy_state(struct xxh64_state *dst, const struct xxh64_state *src)
{
	memcpy(dst, src, sizeof(*dst));
}
EXPORT_SYMBOL(xxh64_copy_state);

/*-***************************
 * Simple Hash Functions
 ****************************/
static uint32_t xxh32_round(uint32_t seed, const uint32_t input)
{
	seed += input * PRIME32_2;
	seed = xxh_rotl32(seed, 13);
	seed *= PRIME32_1;
	return seed;
}

uint32_t xxh32(const void *input, const size_t len, const uint32_t seed)
{
	const uint8_t *p = (const uint8_t *)input;
	const uint8_t *b_end = p + len;
	uint32_t h32;

	if (len >= 16) {
		const uint8_t *const limit = b_end - 16;
		uint32_t v1 = seed + PRIME32_1 + PRIME32_2;
		uint32_t v2 = seed + PRIME32_2;
		uint32_t v3 = seed + 0;
		uint32_t v4 = seed - PRIME32_1;

		do {
			v1 = xxh32_round(v1, get_unaligned_le32(p));
			p += 4;
			v2 = xxh32_round(v2, get_unaligned_le32(p));
			p += 4;
			v3 = xxh32_round(v3, get_unaligned_le32(p));
			p += 4;
			v4 = xxh32_round(v4, get_unaligned_le32(p));
			p += 4;
		} while (p <= limit);

		h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) +
			xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18);
	} else {
		h32 = seed + PRIME32_5;
	}

	h32 += (uint32_t)len;

	while (p + 4 <= b_end) {
		h32 += get_unaligned_le32(p) * PRIME32_3;
		h32 = xxh_rotl32(h32, 17) * PRIME32_4;
		p += 4;
	}

	while (p < b_end) {
		h32 += (*p) * PRIME32_5;
		h32 = xxh_rotl32(h32, 11) * PRIME32_1;
		p++;
	}

	h32 ^= h32 >> 15;
	h32 *= PRIME32_2;
	h32 ^= h32 >> 13;
	h32 *= PRIME32_3;
	h32 ^= h32 >> 16;

	return h32;
}
EXPORT_SYMBOL(xxh32);

static uint64_t xxh64_round(uint64_t acc, const uint64_t input)
{
	acc += input * PRIME64_2;
	acc = xxh_rotl64(acc, 31);
	acc *= PRIME64_1;
	return acc;
}

static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val)
{
	val = xxh64_round(0, val);
	acc ^= val;
	acc = acc * PRIME64_1 + PRIME64_4;
	return acc;
}

uint64_t xxh64(const void *input, const size_t len, const uint64_t seed)
{
	const uint8_t *p = (const uint8_t *)input;
	const uint8_t *const b_end = p + len;
	uint64_t h64;

	if (len >= 32) {
		const uint8_t *const limit = b_end - 32;
		uint64_t v1 = seed + PRIME64_1 + PRIME64_2;
		uint64_t v2 = seed + PRIME64_2;
		uint64_t v3 = seed + 0;
		uint64_t v4 = seed - PRIME64_1;

		do {
			v1 = xxh64_round(v1, get_unaligned_le64(p));
			p += 8;
			v2 = xxh64_round(v2, get_unaligned_le64(p));
			p += 8;
			v3 = xxh64_round(v3, get_unaligned_le64(p));
			p += 8;
			v4 = xxh64_round(v4, get_unaligned_le64(p));
			p += 8;
		} while (p <= limit);

		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
		h64 = xxh64_merge_round(h64, v1);
		h64 = xxh64_merge_round(h64, v2);
		h64 = xxh64_merge_round(h64, v3);
		h64 = xxh64_merge_round(h64, v4);

	} else {
		h64  = seed + PRIME64_5;
	}

	h64 += (uint64_t)len;

	while (p + 8 <= b_end) {
		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));

		h64 ^= k1;
		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
		p += 8;
	}

	if (p + 4 <= b_end) {
		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
		p += 4;
	}

	while (p < b_end) {
		h64 ^= (*p) * PRIME64_5;
		h64 = xxh_rotl64(h64, 11) * PRIME64_1;
		p++;
	}

	h64 ^= h64 >> 33;
	h64 *= PRIME64_2;
	h64 ^= h64 >> 29;
	h64 *= PRIME64_3;
	h64 ^= h64 >> 32;

	return h64;
}
EXPORT_SYMBOL(xxh64);

/*-**************************************************
 * Advanced Hash Functions
 ***************************************************/
void xxh32_reset(struct xxh32_state *statePtr, const uint32_t seed)
{
	/* use a local state for memcpy() to avoid strict-aliasing warnings */
	struct xxh32_state state;

	memset(&state, 0, sizeof(state));
	state.v1 = seed + PRIME32_1 + PRIME32_2;
	state.v2 = seed + PRIME32_2;
	state.v3 = seed + 0;
	state.v4 = seed - PRIME32_1;
	memcpy(statePtr, &state, sizeof(state));
}
EXPORT_SYMBOL(xxh32_reset);

void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed)
{
	/* use a local state for memcpy() to avoid strict-aliasing warnings */
	struct xxh64_state state;

	memset(&state, 0, sizeof(state));
	state.v1 = seed + PRIME64_1 + PRIME64_2;
	state.v2 = seed + PRIME64_2;
	state.v3 = seed + 0;
	state.v4 = seed - PRIME64_1;
	memcpy(statePtr, &state, sizeof(state));
}
EXPORT_SYMBOL(xxh64_reset);

int xxh32_update(struct xxh32_state *state, const void *input, const size_t len)
{
	const uint8_t *p = (const uint8_t *)input;
	const uint8_t *const b_end = p + len;

	if (input == NULL)
		return -EINVAL;

	state->total_len_32 += (uint32_t)len;
	state->large_len |= (len >= 16) | (state->total_len_32 >= 16);

	if (state->memsize + len < 16) { /* fill in tmp buffer */
		memcpy((uint8_t *)(state->mem32) + state->memsize, input, len);
		state->memsize += (uint32_t)len;
		return 0;
	}

	if (state->memsize) { /* some data left from previous update */
		const uint32_t *p32 = state->mem32;

		memcpy((uint8_t *)(state->mem32) + state->memsize, input,
			16 - state->memsize);

		state->v1 = xxh32_round(state->v1, get_unaligned_le32(p32));
		p32++;
		state->v2 = xxh32_round(state->v2, get_unaligned_le32(p32));
		p32++;
		state->v3 = xxh32_round(state->v3, get_unaligned_le32(p32));
		p32++;
		state->v4 = xxh32_round(state->v4, get_unaligned_le32(p32));
		p32++;

		p += 16-state->memsize;
		state->memsize = 0;
	}

	if (p <= b_end - 16) {
		const uint8_t *const limit = b_end - 16;
		uint32_t v1 = state->v1;
		uint32_t v2 = state->v2;
		uint32_t v3 = state->v3;
		uint32_t v4 = state->v4;

		do {
			v1 = xxh32_round(v1, get_unaligned_le32(p));
			p += 4;
			v2 = xxh32_round(v2, get_unaligned_le32(p));
			p += 4;
			v3 = xxh32_round(v3, get_unaligned_le32(p));
			p += 4;
			v4 = xxh32_round(v4, get_unaligned_le32(p));
			p += 4;
		} while (p <= limit);

		state->v1 = v1;
		state->v2 = v2;
		state->v3 = v3;
		state->v4 = v4;
	}

	if (p < b_end) {
		memcpy(state->mem32, p, (size_t)(b_end-p));
		state->memsize = (uint32_t)(b_end-p);
	}

	return 0;
}
EXPORT_SYMBOL(xxh32_update);

uint32_t xxh32_digest(const struct xxh32_state *state)
{
	const uint8_t *p = (const uint8_t *)state->mem32;
	const uint8_t *const b_end = (const uint8_t *)(state->mem32) +
		state->memsize;
	uint32_t h32;

	if (state->large_len) {
		h32 = xxh_rotl32(state->v1, 1) + xxh_rotl32(state->v2, 7) +
			xxh_rotl32(state->v3, 12) + xxh_rotl32(state->v4, 18);
	} else {
		h32 = state->v3 /* == seed */ + PRIME32_5;
	}

	h32 += state->total_len_32;

	while (p + 4 <= b_end) {
		h32 += get_unaligned_le32(p) * PRIME32_3;
		h32 = xxh_rotl32(h32, 17) * PRIME32_4;
		p += 4;
	}

	while (p < b_end) {
		h32 += (*p) * PRIME32_5;
		h32 = xxh_rotl32(h32, 11) * PRIME32_1;
		p++;
	}

	h32 ^= h32 >> 15;
	h32 *= PRIME32_2;
	h32 ^= h32 >> 13;
	h32 *= PRIME32_3;
	h32 ^= h32 >> 16;

	return h32;
}
EXPORT_SYMBOL(xxh32_digest);

int xxh64_update(struct xxh64_state *state, const void *input, const size_t len)
{
	const uint8_t *p = (const uint8_t *)input;
	const uint8_t *const b_end = p + len;

	if (input == NULL)
		return -EINVAL;

	state->total_len += len;

	if (state->memsize + len < 32) { /* fill in tmp buffer */
		memcpy(((uint8_t *)state->mem64) + state->memsize, input, len);
		state->memsize += (uint32_t)len;
		return 0;
	}

	if (state->memsize) { /* tmp buffer is full */
		uint64_t *p64 = state->mem64;

		memcpy(((uint8_t *)p64) + state->memsize, input,
			32 - state->memsize);

		state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64));
		p64++;
		state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64));
		p64++;
		state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64));
		p64++;
		state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64));

		p += 32 - state->memsize;
		state->memsize = 0;
	}

	if (p + 32 <= b_end) {
		const uint8_t *const limit = b_end - 32;
		uint64_t v1 = state->v1;
		uint64_t v2 = state->v2;
		uint64_t v3 = state->v3;
		uint64_t v4 = state->v4;

		do {
			v1 = xxh64_round(v1, get_unaligned_le64(p));
			p += 8;
			v2 = xxh64_round(v2, get_unaligned_le64(p));
			p += 8;
			v3 = xxh64_round(v3, get_unaligned_le64(p));
			p += 8;
			v4 = xxh64_round(v4, get_unaligned_le64(p));
			p += 8;
		} while (p <= limit);

		state->v1 = v1;
		state->v2 = v2;
		state->v3 = v3;
		state->v4 = v4;
	}

	if (p < b_end) {
		memcpy(state->mem64, p, (size_t)(b_end-p));
		state->memsize = (uint32_t)(b_end - p);
	}

	return 0;
}
EXPORT_SYMBOL(xxh64_update);

uint64_t xxh64_digest(const struct xxh64_state *state)
{
	const uint8_t *p = (const uint8_t *)state->mem64;
	const uint8_t *const b_end = (const uint8_t *)state->mem64 +
		state->memsize;
	uint64_t h64;

	if (state->total_len >= 32) {
		const uint64_t v1 = state->v1;
		const uint64_t v2 = state->v2;
		const uint64_t v3 = state->v3;
		const uint64_t v4 = state->v4;

		h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
			xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
		h64 = xxh64_merge_round(h64, v1);
		h64 = xxh64_merge_round(h64, v2);
		h64 = xxh64_merge_round(h64, v3);
		h64 = xxh64_merge_round(h64, v4);
	} else {
		h64  = state->v3 + PRIME64_5;
	}

	h64 += (uint64_t)state->total_len;

	while (p + 8 <= b_end) {
		const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));

		h64 ^= k1;
		h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
		p += 8;
	}

	if (p + 4 <= b_end) {
		h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
		h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
		p += 4;
	}

	while (p < b_end) {
		h64 ^= (*p) * PRIME64_5;
		h64 = xxh_rotl64(h64, 11) * PRIME64_1;
		p++;
	}

	h64 ^= h64 >> 33;
	h64 *= PRIME64_2;
	h64 ^= h64 >> 29;
	h64 *= PRIME64_3;
	h64 ^= h64 >> 32;

	return h64;
}
EXPORT_SYMBOL(xxh64_digest);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("xxHash");
Commit	Line	Data
5d240522 NT	1	/*
	2	* xxHash - Extremely Fast Hash algorithm
	3	* Copyright (C) 2012-2016, Yann Collet.
	4	*
	5	* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
	6	*
	7	* Redistribution and use in source and binary forms, with or without
	8	* modification, are permitted provided that the following conditions are
	9	* met:
	10	*
	11	* * Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* * Redistributions in binary form must reproduce the above
	14	* copyright notice, this list of conditions and the following disclaimer
	15	* in the documentation and/or other materials provided with the
	16	* distribution.
	17	*
	18	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	19	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	20	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	21	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	22	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	23	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	24	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	25	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	26	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	27	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	28	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	29	*
	30	* This program is free software; you can redistribute it and/or modify it under
	31	* the terms of the GNU General Public License version 2 as published by the
	32	* Free Software Foundation. This program is dual-licensed; you may select
	33	* either version 2 of the GNU General Public License ("GPL") or BSD license
	34	* ("BSD").
	35	*
	36	* You can contact the author at:
d89775fc	37	* - xxHash homepage: https://cyan4973.github.io/xxHash/
5d240522 NT	38	* - xxHash source repository: https://github.com/Cyan4973/xxHash
	39	*/
	40
	41	#include <asm/unaligned.h>
	42	#include <linux/errno.h>
	43	#include <linux/compiler.h>
	44	#include <linux/kernel.h>
	45	#include <linux/module.h>
	46	#include <linux/string.h>
	47	#include <linux/xxhash.h>
	48
	49	/-************************************
	50	* Macros
	51	**************************************/
	52	#define xxh_rotl32(x, r) ((x << r) \| (x >> (32 - r)))
	53	#define xxh_rotl64(x, r) ((x << r) \| (x >> (64 - r)))
	54
	55	#ifdef __LITTLE_ENDIAN
	56	# define XXH_CPU_LITTLE_ENDIAN 1
	57	#else
	58	# define XXH_CPU_LITTLE_ENDIAN 0
	59	#endif
	60
	61	/-************************************
	62	* Constants
	63	**************************************/
	64	static const uint32_t PRIME32_1 = 2654435761U;
	65	static const uint32_t PRIME32_2 = 2246822519U;
	66	static const uint32_t PRIME32_3 = 3266489917U;
	67	static const uint32_t PRIME32_4 = 668265263U;
	68	static const uint32_t PRIME32_5 = 374761393U;
	69
	70	static const uint64_t PRIME64_1 = 11400714785074694791ULL;
	71	static const uint64_t PRIME64_2 = 14029467366897019727ULL;
	72	static const uint64_t PRIME64_3 = 1609587929392839161ULL;
	73	static const uint64_t PRIME64_4 = 9650029242287828579ULL;
	74	static const uint64_t PRIME64_5 = 2870177450012600261ULL;
	75
	76	/-*************************
	77	* Utils
	78	***************************/
	79	void xxh32_copy_state(struct xxh32_state dst, const struct xxh32_state src)
	80	{
	81	memcpy(dst, src, sizeof(*dst));
	82	}
	83	EXPORT_SYMBOL(xxh32_copy_state);
	84
	85	void xxh64_copy_state(struct xxh64_state dst, const struct xxh64_state src)
	86	{
	87	memcpy(dst, src, sizeof(*dst));
	88	}
	89	EXPORT_SYMBOL(xxh64_copy_state);
	90
	91	/-**************************
	92	* Simple Hash Functions
	93	****************************/
	94	static uint32_t xxh32_round(uint32_t seed, const uint32_t input)
	95	{
	96	seed += input * PRIME32_2;
	97	seed = xxh_rotl32(seed, 13);
	98	seed *= PRIME32_1;
	99	return seed;
	100	}
	101
102	uint32_t xxh32(const void *input, const size_t len, const uint32_t seed)
103	{
104	const uint8_t p = (const uint8_t )input;
105	const uint8_t *b_end = p + len;
106	uint32_t h32;
107
108	if (len >= 16) {
109	const uint8_t *const limit = b_end - 16;
110	uint32_t v1 = seed + PRIME32_1 + PRIME32_2;
111	uint32_t v2 = seed + PRIME32_2;
112	uint32_t v3 = seed + 0;
113	uint32_t v4 = seed - PRIME32_1;
114
115	do {
116	v1 = xxh32_round(v1, get_unaligned_le32(p));
117	p += 4;
118	v2 = xxh32_round(v2, get_unaligned_le32(p));
119	p += 4;
120	v3 = xxh32_round(v3, get_unaligned_le32(p));
121	p += 4;
122	v4 = xxh32_round(v4, get_unaligned_le32(p));
123	p += 4;
124	} while (p <= limit);
125
126	h32 = xxh_rotl32(v1, 1) + xxh_rotl32(v2, 7) +
127	xxh_rotl32(v3, 12) + xxh_rotl32(v4, 18);
128	} else {
129	h32 = seed + PRIME32_5;
130	}
131
132	h32 += (uint32_t)len;
133
134	while (p + 4 <= b_end) {
135	h32 += get_unaligned_le32(p) * PRIME32_3;
136	h32 = xxh_rotl32(h32, 17) * PRIME32_4;
137	p += 4;
138	}
139
140	while (p < b_end) {
141	h32 += (p) PRIME32_5;
142	h32 = xxh_rotl32(h32, 11) * PRIME32_1;
143	p++;
144	}
145
146	h32 ^= h32 >> 15;
147	h32 *= PRIME32_2;
148	h32 ^= h32 >> 13;
149	h32 *= PRIME32_3;
150	h32 ^= h32 >> 16;
151
152	return h32;
153	}
154	EXPORT_SYMBOL(xxh32);
155
156	static uint64_t xxh64_round(uint64_t acc, const uint64_t input)
157	{
158	acc += input * PRIME64_2;
159	acc = xxh_rotl64(acc, 31);
160	acc *= PRIME64_1;
161	return acc;
162	}
163
164	static uint64_t xxh64_merge_round(uint64_t acc, uint64_t val)
165	{
166	val = xxh64_round(0, val);
167	acc ^= val;
168	acc = acc * PRIME64_1 + PRIME64_4;
169	return acc;
170	}
171
172	uint64_t xxh64(const void *input, const size_t len, const uint64_t seed)
173	{
174	const uint8_t p = (const uint8_t )input;
175	const uint8_t *const b_end = p + len;
176	uint64_t h64;
177
178	if (len >= 32) {
179	const uint8_t *const limit = b_end - 32;
180	uint64_t v1 = seed + PRIME64_1 + PRIME64_2;
181	uint64_t v2 = seed + PRIME64_2;
182	uint64_t v3 = seed + 0;
183	uint64_t v4 = seed - PRIME64_1;
184
185	do {
186	v1 = xxh64_round(v1, get_unaligned_le64(p));
187	p += 8;
188	v2 = xxh64_round(v2, get_unaligned_le64(p));
189	p += 8;
190	v3 = xxh64_round(v3, get_unaligned_le64(p));
191	p += 8;
192	v4 = xxh64_round(v4, get_unaligned_le64(p));
193	p += 8;
194	} while (p <= limit);
195
196	h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
197	xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
198	h64 = xxh64_merge_round(h64, v1);
199	h64 = xxh64_merge_round(h64, v2);
200	h64 = xxh64_merge_round(h64, v3);
201	h64 = xxh64_merge_round(h64, v4);
202
203	} else {
204	h64 = seed + PRIME64_5;
205	}
206
207	h64 += (uint64_t)len;
208
209	while (p + 8 <= b_end) {
210	const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));
211
212	h64 ^= k1;
213	h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
214	p += 8;
215	}
216
217	if (p + 4 <= b_end) {
218	h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
219	h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
220	p += 4;
221	}
222
223	while (p < b_end) {
224	h64 ^= (p) PRIME64_5;
225	h64 = xxh_rotl64(h64, 11) * PRIME64_1;
226	p++;
227	}
228
229	h64 ^= h64 >> 33;
230	h64 *= PRIME64_2;
231	h64 ^= h64 >> 29;
232	h64 *= PRIME64_3;
233	h64 ^= h64 >> 32;
234
235	return h64;
236	}
237	EXPORT_SYMBOL(xxh64);
238
239	/-*************************************************
240	* Advanced Hash Functions
241	***************************************************/
242	void xxh32_reset(struct xxh32_state *statePtr, const uint32_t seed)
243	{
244	/* use a local state for memcpy() to avoid strict-aliasing warnings */
245	struct xxh32_state state;
246
247	memset(&state, 0, sizeof(state));
248	state.v1 = seed + PRIME32_1 + PRIME32_2;
249	state.v2 = seed + PRIME32_2;
250	state.v3 = seed + 0;
251	state.v4 = seed - PRIME32_1;
252	memcpy(statePtr, &state, sizeof(state));
253	}
254	EXPORT_SYMBOL(xxh32_reset);
255
256	void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed)
257	{
258	/* use a local state for memcpy() to avoid strict-aliasing warnings */
259	struct xxh64_state state;
260
261	memset(&state, 0, sizeof(state));
262	state.v1 = seed + PRIME64_1 + PRIME64_2;
263	state.v2 = seed + PRIME64_2;
264	state.v3 = seed + 0;
265	state.v4 = seed - PRIME64_1;
266	memcpy(statePtr, &state, sizeof(state));
267	}
268	EXPORT_SYMBOL(xxh64_reset);
269
270	int xxh32_update(struct xxh32_state state, const void input, const size_t len)
271	{
272	const uint8_t p = (const uint8_t )input;
273	const uint8_t *const b_end = p + len;
274
275	if (input == NULL)
276	return -EINVAL;
277
278	state->total_len_32 += (uint32_t)len;
279	state->large_len \|= (len >= 16) \| (state->total_len_32 >= 16);
280
281	if (state->memsize + len < 16) { /* fill in tmp buffer */
282	memcpy((uint8_t *)(state->mem32) + state->memsize, input, len);
283	state->memsize += (uint32_t)len;
284	return 0;
285	}
286
287	if (state->memsize) { /* some data left from previous update */
288	const uint32_t *p32 = state->mem32;
289
290	memcpy((uint8_t *)(state->mem32) + state->memsize, input,
291	16 - state->memsize);
292
293	state->v1 = xxh32_round(state->v1, get_unaligned_le32(p32));
294	p32++;
295	state->v2 = xxh32_round(state->v2, get_unaligned_le32(p32));
296	p32++;
297	state->v3 = xxh32_round(state->v3, get_unaligned_le32(p32));
298	p32++;
299	state->v4 = xxh32_round(state->v4, get_unaligned_le32(p32));
300	p32++;
301
302	p += 16-state->memsize;
303	state->memsize = 0;
304	}
305
306	if (p <= b_end - 16) {
307	const uint8_t *const limit = b_end - 16;
308	uint32_t v1 = state->v1;
309	uint32_t v2 = state->v2;
310	uint32_t v3 = state->v3;
311	uint32_t v4 = state->v4;
312
313	do {
314	v1 = xxh32_round(v1, get_unaligned_le32(p));
315	p += 4;
316	v2 = xxh32_round(v2, get_unaligned_le32(p));
317	p += 4;
318	v3 = xxh32_round(v3, get_unaligned_le32(p));
319	p += 4;
320	v4 = xxh32_round(v4, get_unaligned_le32(p));
321	p += 4;
322	} while (p <= limit);
323
324	state->v1 = v1;
325	state->v2 = v2;
326	state->v3 = v3;
327	state->v4 = v4;
328	}
329
330	if (p < b_end) {
331	memcpy(state->mem32, p, (size_t)(b_end-p));
332	state->memsize = (uint32_t)(b_end-p);
333	}
334
335	return 0;
336	}
337	EXPORT_SYMBOL(xxh32_update);
338
339	uint32_t xxh32_digest(const struct xxh32_state *state)
340	{
341	const uint8_t p = (const uint8_t )state->mem32;
342	const uint8_t const b_end = (const uint8_t )(state->mem32) +
343	state->memsize;
344	uint32_t h32;
345
346	if (state->large_len) {
347	h32 = xxh_rotl32(state->v1, 1) + xxh_rotl32(state->v2, 7) +
348	xxh_rotl32(state->v3, 12) + xxh_rotl32(state->v4, 18);
349	} else {
350	h32 = state->v3 /* == seed */ + PRIME32_5;
351	}
352
353	h32 += state->total_len_32;
354
355	while (p + 4 <= b_end) {
356	h32 += get_unaligned_le32(p) * PRIME32_3;
357	h32 = xxh_rotl32(h32, 17) * PRIME32_4;
358	p += 4;
359	}
360
361	while (p < b_end) {
362	h32 += (p) PRIME32_5;
363	h32 = xxh_rotl32(h32, 11) * PRIME32_1;
364	p++;
365	}
366
367	h32 ^= h32 >> 15;
368	h32 *= PRIME32_2;
369	h32 ^= h32 >> 13;
370	h32 *= PRIME32_3;
371	h32 ^= h32 >> 16;
372
373	return h32;
374	}
375	EXPORT_SYMBOL(xxh32_digest);
376
377	int xxh64_update(struct xxh64_state state, const void input, const size_t len)
378	{
379	const uint8_t p = (const uint8_t )input;
380	const uint8_t *const b_end = p + len;
381
382	if (input == NULL)
383	return -EINVAL;
384
385	state->total_len += len;
386
387	if (state->memsize + len < 32) { /* fill in tmp buffer */
388	memcpy(((uint8_t *)state->mem64) + state->memsize, input, len);
389	state->memsize += (uint32_t)len;
390	return 0;
391	}
392
393	if (state->memsize) { /* tmp buffer is full */
394	uint64_t *p64 = state->mem64;
395
396	memcpy(((uint8_t *)p64) + state->memsize, input,
397	32 - state->memsize);
398
399	state->v1 = xxh64_round(state->v1, get_unaligned_le64(p64));
400	p64++;
401	state->v2 = xxh64_round(state->v2, get_unaligned_le64(p64));
402	p64++;
403	state->v3 = xxh64_round(state->v3, get_unaligned_le64(p64));
404	p64++;
405	state->v4 = xxh64_round(state->v4, get_unaligned_le64(p64));
406
407	p += 32 - state->memsize;
408	state->memsize = 0;
409	}
410
411	if (p + 32 <= b_end) {
412	const uint8_t *const limit = b_end - 32;
413	uint64_t v1 = state->v1;
414	uint64_t v2 = state->v2;
415	uint64_t v3 = state->v3;
416	uint64_t v4 = state->v4;
417
418	do {
419	v1 = xxh64_round(v1, get_unaligned_le64(p));
420	p += 8;
421	v2 = xxh64_round(v2, get_unaligned_le64(p));
422	p += 8;
423	v3 = xxh64_round(v3, get_unaligned_le64(p));
424	p += 8;
425	v4 = xxh64_round(v4, get_unaligned_le64(p));
426	p += 8;
427	} while (p <= limit);
428
429	state->v1 = v1;
430	state->v2 = v2;
431	state->v3 = v3;
432	state->v4 = v4;
433	}
434
435	if (p < b_end) {
436	memcpy(state->mem64, p, (size_t)(b_end-p));
437	state->memsize = (uint32_t)(b_end - p);
438	}
439
440	return 0;
441	}
442	EXPORT_SYMBOL(xxh64_update);
443
444	uint64_t xxh64_digest(const struct xxh64_state *state)
445	{
446	const uint8_t p = (const uint8_t )state->mem64;
447	const uint8_t const b_end = (const uint8_t )state->mem64 +
448	state->memsize;
449	uint64_t h64;
450
451	if (state->total_len >= 32) {
452	const uint64_t v1 = state->v1;
453	const uint64_t v2 = state->v2;
454	const uint64_t v3 = state->v3;
455	const uint64_t v4 = state->v4;
456
457	h64 = xxh_rotl64(v1, 1) + xxh_rotl64(v2, 7) +
458	xxh_rotl64(v3, 12) + xxh_rotl64(v4, 18);
459	h64 = xxh64_merge_round(h64, v1);
460	h64 = xxh64_merge_round(h64, v2);
461	h64 = xxh64_merge_round(h64, v3);
462	h64 = xxh64_merge_round(h64, v4);
463	} else {
464	h64 = state->v3 + PRIME64_5;
465	}
466
467	h64 += (uint64_t)state->total_len;
468
469	while (p + 8 <= b_end) {
470	const uint64_t k1 = xxh64_round(0, get_unaligned_le64(p));
471
472	h64 ^= k1;
473	h64 = xxh_rotl64(h64, 27) * PRIME64_1 + PRIME64_4;
474	p += 8;
475	}
476
477	if (p + 4 <= b_end) {
478	h64 ^= (uint64_t)(get_unaligned_le32(p)) * PRIME64_1;
479	h64 = xxh_rotl64(h64, 23) * PRIME64_2 + PRIME64_3;
480	p += 4;
481	}
482
483	while (p < b_end) {
484	h64 ^= (p) PRIME64_5;
485	h64 = xxh_rotl64(h64, 11) * PRIME64_1;
486	p++;
487	}
488
489	h64 ^= h64 >> 33;
490	h64 *= PRIME64_2;
491	h64 ^= h64 >> 29;
492	h64 *= PRIME64_3;
493	h64 ^= h64 >> 32;
494
495	return h64;
496	}
497	EXPORT_SYMBOL(xxh64_digest);
498
499	MODULE_LICENSE("Dual BSD/GPL");
500	MODULE_DESCRIPTION("xxHash");