arch/x86/crypto/ghash-clmulni-intel_asm.S

   1 /*
   2  * Accelerated GHASH implementation with Intel PCLMULQDQ-NI
   3  * instructions. This file contains accelerated part of ghash
   4  * implementation. More information about PCLMULQDQ can be found at:
   5  *
   6  * http://software.intel.com/en-us/articles/carry-less-multiplication-and-its-usage-for-computing-the-gcm-mode/
   7  *
   8  * Copyright (c) 2009 Intel Corp.
   9  *   Author: Huang Ying <ying.huang@intel.com>
  10  *           Vinodh Gopal
  11  *           Erdinc Ozturk
  12  *           Deniz Karakoyunlu
  13  *
  14  * This program is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU General Public License version 2 as published
  16  * by the Free Software Foundation.
  17  */
  18
  19 #include <linux/linkage.h>
  20 #include <asm/inst.h>
  21
  22 .data
  23
  24 .align 16
  25 .Lbswap_mask:
  26         .octa 0x000102030405060708090a0b0c0d0e0f
  27
  28 #define DATA    %xmm0
  29 #define SHASH   %xmm1
  30 #define T1      %xmm2
  31 #define T2      %xmm3
  32 #define T3      %xmm4
  33 #define BSWAP   %xmm5
  34 #define IN1     %xmm6
  35
  36 .text
  37
  38 /*
  39  * __clmul_gf128mul_ble:        internal ABI
  40  * input:
  41  *      DATA:                   operand1
  42  *      SHASH:                  operand2, hash_key << 1 mod poly
  43  * output:
  44  *      DATA:                   operand1 * operand2 mod poly
  45  * changed:
  46  *      T1
  47  *      T2
  48  *      T3
  49  */
  50 __clmul_gf128mul_ble:
  51         movaps DATA, T1
  52         pshufd $0b01001110, DATA, T2
  53         pshufd $0b01001110, SHASH, T3
  54         pxor DATA, T2
  55         pxor SHASH, T3
  56
  57         PCLMULQDQ 0x00 SHASH DATA       # DATA = a0 * b0
  58         PCLMULQDQ 0x11 SHASH T1         # T1 = a1 * b1
  59         PCLMULQDQ 0x00 T3 T2            # T2 = (a1 + a0) * (b1 + b0)
  60         pxor DATA, T2
  61         pxor T1, T2                     # T2 = a0 * b1 + a1 * b0
  62
  63         movaps T2, T3
  64         pslldq $8, T3
  65         psrldq $8, T2
  66         pxor T3, DATA
  67         pxor T2, T1                     # <T1:DATA> is result of
  68                                         # carry-less multiplication
  69
  70         # first phase of the reduction
  71         movaps DATA, T3
  72         psllq $1, T3
  73         pxor DATA, T3
  74         psllq $5, T3
  75         pxor DATA, T3
  76         psllq $57, T3
  77         movaps T3, T2
  78         pslldq $8, T2
  79         psrldq $8, T3
  80         pxor T2, DATA
  81         pxor T3, T1
  82
  83         # second phase of the reduction
  84         movaps DATA, T2
  85         psrlq $5, T2
  86         pxor DATA, T2
  87         psrlq $1, T2
  88         pxor DATA, T2
  89         psrlq $1, T2
  90         pxor T2, T1
  91         pxor T1, DATA
  92         ret
  93 ENDPROC(__clmul_gf128mul_ble)
  94
  95 /* void clmul_ghash_mul(char *dst, const u128 *shash) */
  96 ENTRY(clmul_ghash_mul)
  97         movups (%rdi), DATA
  98         movups (%rsi), SHASH
  99         movaps .Lbswap_mask, BSWAP
 100         PSHUFB_XMM BSWAP DATA
 101         call __clmul_gf128mul_ble
 102         PSHUFB_XMM BSWAP DATA
 103         movups DATA, (%rdi)
 104         ret
 105 ENDPROC(clmul_ghash_mul)
 106
 107 /*
 108  * void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
 109  *                         const u128 *shash);
 110  */
 111 ENTRY(clmul_ghash_update)
 112         cmp $16, %rdx
 113         jb .Lupdate_just_ret    # check length
 114         movaps .Lbswap_mask, BSWAP
 115         movups (%rdi), DATA
 116         movups (%rcx), SHASH
 117         PSHUFB_XMM BSWAP DATA
 118 .align 4
 119 .Lupdate_loop:
 120         movups (%rsi), IN1
 121         PSHUFB_XMM BSWAP IN1
 122         pxor IN1, DATA
 123         call __clmul_gf128mul_ble
 124         sub $16, %rdx
 125         add $16, %rsi
 126         cmp $16, %rdx
 127         jge .Lupdate_loop
 128         PSHUFB_XMM BSWAP DATA
 129         movups DATA, (%rdi)
 130 .Lupdate_just_ret:
 131         ret
 132 ENDPROC(clmul_ghash_update)