/*
* Accelerated GHASH implementation with Intel PCLMULQDQ-NI
* instructions. This file contains accelerated part of ghash
* implementation. More information about PCLMULQDQ can be found at:
*
* http://software.intel.com/en-us/articles/carry-less-multiplication-and-its-usage-for-computing-the-gcm-mode/
*
* Copyright (c) 2009 Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
* Vinodh Gopal
* Erdinc Ozturk
* Deniz Karakoyunlu
*
* 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.
*/
#include <linux/linkage.h>
#include <asm/inst.h>
.data
.align 16
.Lbswap_mask:
.octa 0x000102030405060708090a0b0c0d0e0f
.Lpoly:
.octa 0xc2000000000000000000000000000001
.Ltwo_one:
.octa 0x00000001000000000000000000000001
#define DATA %xmm0
#define SHASH %xmm1
#define T1 %xmm2
#define T2 %xmm3
#define T3 %xmm4
#define BSWAP %xmm5
#define IN1 %xmm6
.text
/*
* __clmul_gf128mul_ble: internal ABI
* input:
* DATA: operand1
* SHASH: operand2, hash_key << 1 mod poly
* output:
* DATA: operand1 * operand2 mod poly
* changed:
* T1
* T2
* T3
*/
__clmul_gf128mul_ble:
movaps DATA, T1
pshufd $0b01001110, DATA, T2
pshufd $0b01001110, SHASH, T3
pxor DATA, T2
pxor SHASH, T3
PCLMULQDQ 0x00 SHASH DATA # DATA = a0 * b0
PCLMULQDQ 0x11 SHASH T1 # T1 = a1 * b1
PCLMULQDQ 0x00 T3 T2 # T2 = (a1 + a0) * (b1 + b0)
pxor DATA, T2
pxor T1, T2 # T2 = a0 * b1 + a1 * b0
movaps T2, T3
pslldq $8, T3
psrldq $8, T2
pxor T3, DATA
pxor T2, T1 # <T1:DATA> is result of
# carry-less multiplication
# first phase of the reduction
movaps DATA, T3
psllq $1, T3
pxor DATA, T3
psllq $5, T3
pxor DATA, T3
psllq $57, T3
movaps T3, T2
pslldq $8, T2
psrldq $8, T3
pxor T2, DATA
pxor T3, T1
# second phase of the reduction
movaps DATA, T2
psrlq $5, T2
pxor DATA, T2
psrlq $1, T2
pxor DATA, T2
psrlq $1, T2
pxor T2, T1
pxor T1, DATA
ret
/* void clmul_ghash_mul(char *dst, const be128 *shash) */
ENTRY(clmul_ghash_mul)
movups (%rdi), DATA
movups (%rsi), SHASH
movaps .Lbswap_mask, BSWAP
PSHUFB_XMM BSWAP DATA
call __clmul_gf128mul_ble
PSHUFB_XMM BSWAP DATA
movups DATA, (%rdi)
ret
/*
* void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
* const be128 *shash);
*/
ENTRY(clmul_ghash_update)
cmp $16, %rdx
jb .Lupdate_just_ret # check length
movaps .Lbswap_mask, BSWAP
movups (%rdi), DATA
movups (%rcx), SHASH
PSHUFB_XMM BSWAP DATA
.align 4
.Lupdate_loop:
movups (%rsi), IN1
PSHUFB_XMM BSWAP IN1
pxor IN1, DATA
call __clmul_gf128mul_ble
sub $16, %rdx
add $16, %rsi
cmp $16, %rdx
jge .Lupdate_loop
PSHUFB_XMM BSWAP DATA
movups DATA, (%rdi)
.Lupdate_just_ret:
ret
/*
* void clmul_ghash_setkey(be128 *shash, const u8 *key);
*
* Calculate hash_key << 1 mod poly
*/
ENTRY(clmul_ghash_setkey)
movaps .Lbswap_mask, BSWAP
movups (%rsi), %xmm0
PSHUFB_XMM BSWAP %xmm0
movaps %xmm0, %xmm1
psllq $1, %xmm0
psrlq $63, %xmm1
movaps %xmm1, %xmm2
pslldq $8, %xmm1
psrldq $8, %xmm2
por %xmm1, %xmm0
# reduction
pshufd $0b00100100, %xmm2, %xmm1
pcmpeqd .Ltwo_one, %xmm1
pand .Lpoly, %xmm1
pxor %xmm1, %xmm0
movups %xmm0, (%rdi)
ret
