48 lines
1.2 KiB
C
48 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Accelerated CRC64 (NVMe) using ARM NEON C intrinsics
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <asm/neon-intrinsics.h>
|
|
|
|
#include "crc64-neon.h"
|
|
|
|
u64 crc64_nvme_neon(u64 crc, const u8 *p, size_t len);
|
|
|
|
/* x^191 mod G, x^127 mod G */
|
|
static const u64 fold_consts_val[2] = { 0xeadc41fd2ba3d420ULL,
|
|
0x21e9761e252621acULL };
|
|
/* floor(x^127 / G), (G - x^64) / x */
|
|
static const u64 bconsts_val[2] = { 0x27ecfa329aef9f77ULL,
|
|
0x34d926535897936aULL };
|
|
|
|
u64 crc64_nvme_neon(u64 crc, const u8 *p, size_t len)
|
|
{
|
|
uint64x2_t fold_consts = vld1q_u64(fold_consts_val);
|
|
uint64x2_t v0 = { crc, 0 };
|
|
uint64x2_t zero = { };
|
|
|
|
for (;;) {
|
|
v0 ^= vreinterpretq_u64_u8(vld1q_u8(p));
|
|
|
|
p += 16;
|
|
len -= 16;
|
|
if (len < 16)
|
|
break;
|
|
|
|
v0 = pmull64(fold_consts, v0) ^ pmull64_high(fold_consts, v0);
|
|
}
|
|
|
|
/* Multiply the 128-bit value by x^64 and reduce it back to 128 bits. */
|
|
v0 = vextq_u64(v0, zero, 1) ^ pmull64_hi_lo(fold_consts, v0);
|
|
|
|
/* Final Barrett reduction */
|
|
uint64x2_t bconsts = vld1q_u64(bconsts_val);
|
|
uint64x2_t final = pmull64(bconsts, v0);
|
|
|
|
v0 ^= vextq_u64(zero, final, 1) ^ pmull64_hi_lo(bconsts, final);
|
|
|
|
return vgetq_lane_u64(v0, 1);
|
|
}
|