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/*
* Some portions derived from code covered by the following notice:
*
* Copyright (c) 2010-2013 Intel Corporation. All rights reserved.
* All rights reserved.
*
* 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.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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.
*/
#include <linux/hash.h>
#include <linux/init.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/hash.h>
static inline u32 crc32_u32(u32 crc, u32 val)
{
#ifdef CONFIG_AS_CRC32
asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val));
#else
asm (".byte 0xf2, 0x0f, 0x38, 0xf1, 0xc1" : "+a" (crc) : "c" (val));
#endif
return crc;
}
static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed)
{
const u32 *p32 = (const u32 *) data;
u32 i, tmp = 0;
for (i = 0; i < len / 4; i++)
seed = crc32_u32(seed, *p32++);
switch (len & 3) {
case 3:
tmp |= *((const u8 *) p32 + 2) << 16;
/* fallthrough */
case 2:
tmp |= *((const u8 *) p32 + 1) << 8;
/* fallthrough */
case 1:
tmp |= *((const u8 *) p32);
seed = crc32_u32(seed, tmp);
break;
}
return 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, *p32++);
return seed;
}
void __init setup_arch_fast_hash(struct fast_hash_ops *ops)
{
if (cpu_has_xmm4_2) {
ops->hash = intel_crc4_2_hash;
ops->hash2 = intel_crc4_2_hash2;
}
}
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