This implementation takes advantage of research made by Niels Möller to optimize GCM on PowerPC, this optimization yields a +27.7% performance boost on POWER8 over the previous implementation that was based on intel documents. The performance comparison is made by processing 4 blocks per loop without any further optimizations. I made some documentations between the lines but I suggest writing a document similar to the intel ones that go into more details and clarify the preference of this method. I'm also curious if this method can also make a difference in other architectures like ARM, I'm planning to try it out for ARM to figure that out. --- configure.ac | 6 +- gcm.c | 49 +++-- powerpc64/p8/gcm-hash.asm | 502 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 542 insertions(+), 15 deletions(-) create mode 100644 powerpc64/p8/gcm-hash.asm
diff --git a/configure.ac b/configure.ac index 2a47f940..20f7cf74 100644 --- a/configure.ac +++ b/configure.ac @@ -497,7 +497,7 @@ asm_replace_list="aes-encrypt-internal.asm aes-decrypt-internal.asm \ sha3-permute.asm umac-nh.asm umac-nh-n.asm machine.m4"
# Assembler files which generate additional object files if they are used. -asm_nettle_optional_list="gcm-hash8.asm cpuid.asm \ +asm_nettle_optional_list="gcm-hash.asm gcm-hash8.asm cpuid.asm \ aes-encrypt-internal-2.asm aes-decrypt-internal-2.asm memxor-2.asm \ chacha-3core.asm chacha-core-internal-2.asm salsa20-2core.asm \ salsa20-core-internal-2.asm sha1-compress-2.asm sha256-compress-2.asm \ @@ -621,9 +621,9 @@ AH_VERBATIM([HAVE_NATIVE], #undef HAVE_NATIVE_ecc_secp384r1_redc #undef HAVE_NATIVE_ecc_secp521r1_modp #undef HAVE_NATIVE_ecc_secp521r1_redc -#undef HAVE_NATIVE_gcm_init_key8 +#undef HAVE_NATIVE_gcm_init_key +#undef HAVE_NATIVE_gcm_hash #undef HAVE_NATIVE_gcm_hash8 -#undef HAVE_NATIVE_gcm_fill #undef HAVE_NATIVE_salsa20_core #undef HAVE_NATIVE_salsa20_2core #undef HAVE_NATIVE_fat_salsa20_2core diff --git a/gcm.c b/gcm.c index 48b3e75a..81981c1c 100644 --- a/gcm.c +++ b/gcm.c @@ -140,6 +140,19 @@ gcm_gf_mul (union nettle_block16 *x, const union nettle_block16 *table) memcpy (x->b, Z.b, sizeof(Z)); } # elif GCM_TABLE_BITS == 8 +# if HAVE_NATIVE_gcm_init_key + +#define gcm_init_key _nettle_gcm_init_key +void +_nettle_gcm_init_key (union nettle_block16 *table); +# endif /* HAVE_NATIVE_gcm_init_key */ +# if HAVE_NATIVE_gcm_hash + +#define gcm_hash _nettle_gcm_hash +void +_nettle_gcm_hash (const struct gcm_key *key, union nettle_block16 *x, + size_t length, const uint8_t *data); +# endif /* HAVE_NATIVE_gcm_hash */ # if HAVE_NATIVE_gcm_hash8
#define gcm_hash _nettle_gcm_hash8 @@ -228,6 +241,29 @@ gcm_gf_mul (union nettle_block16 *x, const union nettle_block16 *table) /* Increment the rightmost 32 bits. */ #define INC32(block) INCREMENT(4, (block.b) + GCM_BLOCK_SIZE - 4)
+#ifndef gcm_init_key +static void +gcm_init_key(union nettle_block16 *table) +{ +#if GCM_TABLE_BITS + /* Middle element if GCM_TABLE_BITS > 0, otherwise the first + element */ + unsigned i = (1<<GCM_TABLE_BITS)/2; + + /* Algorithm 3 from the gcm paper. First do powers of two, then do + the rest by adding. */ + while (i /= 2) + block16_mulx_ghash(&table[i], &table[2*i]); + for (i = 2; i < 1<<GCM_TABLE_BITS; i *= 2) + { + unsigned j; + for (j = 1; j < i; j++) + block16_xor3(&table[i+j], &table[i], &table[j]); + } +#endif +} +#endif /* !gcm_init_key */ + /* Initialization of GCM. * @ctx: The context of GCM * @cipher: The context of the underlying block cipher @@ -245,18 +281,7 @@ gcm_set_key(struct gcm_key *key, memset(key->h[0].b, 0, GCM_BLOCK_SIZE); f (cipher, GCM_BLOCK_SIZE, key->h[i].b, key->h[0].b);
-#if GCM_TABLE_BITS - /* Algorithm 3 from the gcm paper. First do powers of two, then do - the rest by adding. */ - while (i /= 2) - block16_mulx_ghash(&key->h[i], &key->h[2*i]); - for (i = 2; i < 1<<GCM_TABLE_BITS; i *= 2) - { - unsigned j; - for (j = 1; j < i; j++) - block16_xor3(&key->h[i+j], &key->h[i],&key->h[j]); - } -#endif + gcm_init_key(key->h); }
#ifndef gcm_hash diff --git a/powerpc64/p8/gcm-hash.asm b/powerpc64/p8/gcm-hash.asm new file mode 100644 index 00000000..e79fbdc2 --- /dev/null +++ b/powerpc64/p8/gcm-hash.asm @@ -0,0 +1,502 @@ +C powerpc64/p8/gcm-hash.asm + +ifelse(` + Copyright (C) 2020 Niels Möller and Mamone Tarsha + This file is part of GNU Nettle. + + GNU Nettle is free software: you can redistribute it and/or + modify it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at your + option) any later version. + + or both in parallel, as here. + + GNU Nettle is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see http://www.gnu.org/licenses/. +') + +C Alignment of gcm_key table elements, which is declared in gcm.h +define(`TableElemAlign', `0x100') + +C Register usage: + +define(`SP', `r1') +define(`TOCP', `r2') + +define(`TABLE', `r3') + +define(`ZERO', `v0') +define(`B1', `v1') +define(`EMSB', `v16') +define(`POLY', `v17') +define(`POLY_L', `v1') + +define(`H', `v2') +define(`H2', `v3') +define(`H3', `v4') +define(`H4', `v5') +define(`H1M', `v6') +define(`H1L', `v7') +define(`H2M', `v8') +define(`H2L', `v9') +define(`Hl', `v10') +define(`Hm', `v11') +define(`Hp', `v12') +define(`Hl2', `v13') +define(`Hm2', `v14') +define(`Hp2', `v15') +define(`R', `v13') +define(`F', `v14') +define(`T', `v15') +define(`R2', `v16') +define(`F2', `v17') +define(`T2', `v18') + +define(`LE_TEMP', `v18') +define(`LE_MASK', `v19') + +.file "gcm-hash.asm" + +.text + + C void gcm_init_key (union gcm_block *table) + +C This function populates the gcm table as the following layout +C ******************************************************************************* +C | H1M = (H1 div x⁶⁴)||((H1 mod x⁶⁴) × (x⁶⁴+x⁶³+x⁶²+x⁵⁷)) div x⁶⁴ | +C | H1L = (H1 mod x⁶⁴)||(((H1 mod x⁶⁴) × (x⁶³+x⁶²+x⁵⁷)) mod x⁶⁴) + (H1 div x⁶⁴) | +C | | +C | H2M = (H2 div x⁶⁴)||((H2 mod x⁶⁴) × (x⁶⁴+x⁶³+x⁶²+x⁵⁷)) div x⁶⁴ | +C | H2L = (H2 mod x⁶⁴)||(((H2 mod x⁶⁴) × (x⁶³+x⁶²+x⁵⁷)) mod x⁶⁴) + (H2 div x⁶⁴) | +C | | +C | H3M = (H3 div x⁶⁴)||((H3 mod x⁶⁴) × (x⁶⁴+x⁶³+x⁶²+x⁵⁷)) div x⁶⁴ | +C | H3L = (H3 mod x⁶⁴)||(((H3 mod x⁶⁴) × (x⁶³+x⁶²+x⁵⁷)) mod x⁶⁴) + (H3 div x⁶⁴) | +C | | +C | H4M = (H3 div x⁶⁴)||((H4 mod x⁶⁴) × (x⁶⁴+x⁶³+x⁶²+x⁵⁷)) div x⁶⁴ | +C | H4L = (H3 mod x⁶⁴)||(((H4 mod x⁶⁴) × (x⁶³+x⁶²+x⁵⁷)) mod x⁶⁴) + (H4 div x⁶⁴) | +C ******************************************************************************* + +define(`FUNC_ALIGN', `5') +PROLOGUE(_nettle_gcm_init_key) + DATA_LOAD_VEC(POLY,.polynomial,r7) C 0xC2000000000000000000000000000001 +IF_LE(` + li r8,0 + lvsl LE_MASK,0,r8 C 0x000102030405060708090A0B0C0D0E0F + vspltisb LE_TEMP,0x07 C 0x07070707070707070707070707070707 + vxor LE_MASK,LE_MASK,LE_TEMP C 0x07060504030201000F0E0D0C0B0A0908 +') + + C 'H' is assigned by gcm_set_key() to the middle element of the table + li r10,8*TableElemAlign + lxvd2x VSR(H),r10,TABLE C load 'H' + C byte-reverse of each doubleword permuting on little-endian mode +IF_LE(` + vperm H,H,H,LE_MASK +') + + C --- calculate H = H << 1 mod P(X), P(X) = (x¹²⁸+x¹²⁷+x¹²⁶+x¹²¹+1) --- + + vupkhsb EMSB,H C extend most significant bit to first byte + vspltisb B1,1 C 0x01010101010101010101010101010101 + vspltb EMSB,EMSB,0 C first byte quadword-extend + vsl H,H,B1 C H = H << 1 + vand EMSB,EMSB,POLY C EMSB &= 0xC2000000000000000000000000000001 + vxor ZERO,ZERO,ZERO C 0x00000000000000000000000000000000 + vxor H,H,EMSB C H ^= EMSB + + C --- calculate H^2 = H*H --- + + xxmrghd VSR(POLY_L),VSR(ZERO),VSR(POLY) C 0x0000000000000000C200000000000000 + + C --- Hp = (H mod x⁶⁴) / x⁶⁴ mod P(X) --- + C --- Hp = (H mod x⁶⁴) × (x⁶⁴+x⁶³+x⁶²+x⁵⁷) mod P(X), deg(Hp) ≤ 127 --- + C --- Hp = (H mod x⁶⁴) × (x⁶⁴+x⁶³+x⁶²+x⁵⁷) --- + vpmsumd Hp,H,POLY_L C Hp = (H mod x⁶⁴) × (x⁶³+x⁶²+x⁵⁷) + xxmrgld VSR(Hl),VSR(H),VSR(ZERO) C Hl = (H mod x⁶⁴) × x⁶⁴ + xxswapd VSR(Hm),VSR(H) + vxor Hl,Hl,Hp C Hl = Hl + Hp + vxor Hm,Hm,Hp C Hm = Hm + Hp + xxmrghd VSR(H1M),VSR(H),VSR(Hl) C H1M = (H div x⁶⁴)||(Hl div x⁶⁴) + xxmrgld VSR(H1L),VSR(H),VSR(Hm) C H1L = (H mod x⁶⁴)||(Hl mod x⁶⁴) + + vpmsumd F,H1L,H C F = (H1Lh × Hh) + (H1Ll × Hl) + vpmsumd R,H1M,H C R = (H1Mh × Hh) + (H1Ml × Hl) + + C --- rduction --- + vpmsumd T,F,POLY_L C T = (F mod x⁶⁴) × (x⁶³+x⁶²+x⁵⁷) + xxswapd VSR(H2),VSR(F) + vxor R,R,T C R = R + T + vxor H2,R,H2 + + xxmrgld VSR(Hl),VSR(H2),VSR(ZERO) + xxswapd VSR(Hm),VSR(H2) + vpmsumd Hp,H2,POLY_L + vxor Hl,Hl,Hp + vxor Hm,Hm,Hp + xxmrghd VSR(H2M),VSR(H2),VSR(Hl) + xxmrgld VSR(H2L),VSR(H2),VSR(Hm) + + C store H1M, H1L, H2M, H2L + li r8,1*TableElemAlign + li r9,2*TableElemAlign + li r10,3*TableElemAlign + stxvd2x VSR(H1M),0,TABLE + stxvd2x VSR(H1L),r8,TABLE + stxvd2x VSR(H2M),r9,TABLE + stxvd2x VSR(H2L),r10,TABLE + + C --- calculate H^3 = H^1*H^2, H^4 = H^2*H^2 --- + + vpmsumd F,H1L,H2 + vpmsumd F2,H2L,H2 + vpmsumd R,H1M,H2 + vpmsumd R2,H2M,H2 + + vpmsumd T,F,POLY_L + vpmsumd T2,F2,POLY_L + xxswapd VSR(H3),VSR(F) + xxswapd VSR(H4),VSR(F2) + vxor R,R,T + vxor R2,R2,T2 + vxor H3,R,H3 + vxor H4,R2,H4 + + xxmrgld VSR(Hl),VSR(H3),VSR(ZERO) + xxmrgld VSR(Hl2),VSR(H4),VSR(ZERO) + xxswapd VSR(Hm),VSR(H3) + xxswapd VSR(Hm2),VSR(H4) + vpmsumd Hp,H3,POLY_L + vpmsumd Hp2,H4,POLY_L + vxor Hl,Hl,Hp + vxor Hl2,Hl2,Hp2 + vxor Hm,Hm,Hp + vxor Hm2,Hm2,Hp2 + xxmrghd VSR(H1M),VSR(H3),VSR(Hl) + xxmrghd VSR(H2M),VSR(H4),VSR(Hl2) + xxmrgld VSR(H1L),VSR(H3),VSR(Hm) + xxmrgld VSR(H2L),VSR(H4),VSR(Hm2) + + C store H3M, H3L, H4M, H4L + li r7,4*TableElemAlign + li r8,5*TableElemAlign + li r9,6*TableElemAlign + li r10,7*TableElemAlign + stxvd2x VSR(H1M),r7,TABLE + stxvd2x VSR(H1L),r8,TABLE + stxvd2x VSR(H2M),r9,TABLE + stxvd2x VSR(H2L),r10,TABLE + + blr +EPILOGUE(_nettle_gcm_init_key) + +define(`TABLE', `r3') +define(`X', `r4') +define(`LENGTH', `r5') +define(`DATA', `r6') + +define(`ZERO', `v16') +define(`POLY', `v17') +define(`POLY_L', `v0') + +define(`D', `v1') +define(`C0', `v2') +define(`C1', `v3') +define(`C2', `v4') +define(`C3', `v5') +define(`H1M', `v6') +define(`H1L', `v7') +define(`H2M', `v8') +define(`H2L', `v9') +define(`H3M', `v10') +define(`H3L', `v11') +define(`H4M', `v12') +define(`H4L', `v13') +define(`R', `v14') +define(`F', `v15') +define(`R2', `v16') +define(`F2', `v17') +define(`R3', `v18') +define(`F3', `v20') +define(`R4', `v21') +define(`F4', `v22') +define(`T', `v23') + +define(`LE_TEMP', `v18') +define(`LE_MASK', `v19') + + C void gcm_hash (const struct gcm_key *key, union gcm_block *x, + C size_t length, const uint8_t *data) + +define(`FUNC_ALIGN', `5') +PROLOGUE(_nettle_gcm_hash) + DATA_LOAD_VEC(POLY,.polynomial,r7) +IF_LE(` + li r8,0 + lvsl LE_MASK,0,r8 + vspltisb LE_TEMP,0x07 + vxor LE_MASK,LE_MASK,LE_TEMP +') + vxor ZERO,ZERO,ZERO + xxmrghd VSR(POLY_L),VSR(ZERO),VSR(POLY) + + lxvd2x VSR(D),0,X C load 'X' pointer + C byte-reverse of each doubleword permuting on little-endian mode +IF_LE(` + vperm D,D,D,LE_MASK +') + + C --- process 4 blocks '128-bit each' per one loop --- + + srdi r7,LENGTH,6 C 4-blocks loop count 'LENGTH / (4 * 16)' + cmpldi r7,0 + beq L2x + + mtctr r7 C assign counter register to loop count + + C store non-volatile vector registers + addi r8,SP,-64 + stvx 20,0,r8 + addi r8,r8,16 + stvx 21,0,r8 + addi r8,r8,16 + stvx 22,0,r8 + addi r8,r8,16 + stvx 23,0,r8 + + C load table elements + li r8,1*TableElemAlign + li r9,2*TableElemAlign + li r10,3*TableElemAlign + lxvd2x VSR(H1M),0,TABLE + lxvd2x VSR(H1L),r8,TABLE + lxvd2x VSR(H2M),r9,TABLE + lxvd2x VSR(H2L),r10,TABLE + li r7,4*TableElemAlign + li r8,5*TableElemAlign + li r9,6*TableElemAlign + li r10,7*TableElemAlign + lxvd2x VSR(H3M),r7,TABLE + lxvd2x VSR(H3L),r8,TABLE + lxvd2x VSR(H4M),r9,TABLE + lxvd2x VSR(H4L),r10,TABLE + + li r8,0x10 + li r9,0x20 + li r10,0x30 +.align 5 +L4x_loop: + C input loading + lxvd2x VSR(C0),0,DATA C load C0 + lxvd2x VSR(C1),r8,DATA C load C1 + lxvd2x VSR(C2),r9,DATA C load C2 + lxvd2x VSR(C3),r10,DATA C load C3 + +IF_LE(` + vperm C0,C0,C0,LE_MASK + vperm C1,C1,C1,LE_MASK + vperm C2,C2,C2,LE_MASK + vperm C3,C3,C3,LE_MASK +') + + C previous digest combining + vxor C0,C0,D + + C polynomial multiplication + vpmsumd F2,H3L,C1 + vpmsumd R2,H3M,C1 + vpmsumd F3,H2L,C2 + vpmsumd R3,H2M,C2 + vpmsumd F4,H1L,C3 + vpmsumd R4,H1M,C3 + vpmsumd F,H4L,C0 + vpmsumd R,H4M,C0 + + C deferred recombination of partial products + vxor F3,F3,F4 + vxor R3,R3,R4 + vxor F,F,F2 + vxor R,R,R2 + vxor F,F,F3 + vxor R,R,R3 + + C reduction + vpmsumd T,F,POLY_L + xxswapd VSR(D),VSR(F) + vxor R,R,T + vxor D,R,D + + addi DATA,DATA,0x40 + bdnz L4x_loop + + C restore non-volatile vector registers + addi r8,SP,-64 + lvx 20,0,r8 + addi r8,r8,16 + lvx 21,0,r8 + addi r8,r8,16 + lvx 22,0,r8 + addi r8,r8,16 + lvx 23,0,r8 + + clrldi LENGTH,LENGTH,58 C 'set the high-order 58 bits to zeros' +L2x: + C --- process 2 blocks --- + + srdi r7,LENGTH,5 C 'LENGTH / (2 * 16)' + cmpldi r7,0 + beq L1x + + C load table elements + li r8,1*TableElemAlign + li r9,2*TableElemAlign + li r10,3*TableElemAlign + lxvd2x VSR(H1M),0,TABLE + lxvd2x VSR(H1L),r8,TABLE + lxvd2x VSR(H2M),r9,TABLE + lxvd2x VSR(H2L),r10,TABLE + + C input loading + li r10,0x10 + lxvd2x VSR(C0),0,DATA C load C0 + lxvd2x VSR(C1),r10,DATA C load C1 + +IF_LE(` + vperm C0,C0,C0,LE_MASK + vperm C1,C1,C1,LE_MASK +') + + C previous digest combining + vxor C0,C0,D + + C polynomial multiplication + vpmsumd F2,H1L,C1 + vpmsumd R2,H1M,C1 + vpmsumd F,H2L,C0 + vpmsumd R,H2M,C0 + + C deferred recombination of partial products + vxor F,F,F2 + vxor R,R,R2 + + C reduction + vpmsumd T,F,POLY_L + xxswapd VSR(D),VSR(F) + vxor R,R,T + vxor D,R,D + + addi DATA,DATA,0x20 + clrldi LENGTH,LENGTH,59 C 'set the high-order 59 bits to zeros' +L1x: + C --- process 1 block --- + + srdi r7,LENGTH,4 C 'LENGTH / (1 * 16)' + cmpldi r7,0 + beq Lmod + + C load table elements + li r8,1*TableElemAlign + lxvd2x VSR(H1M),0,TABLE + lxvd2x VSR(H1L),r8,TABLE + + C input loading + lxvd2x VSR(C0),0,DATA C load C0 + +IF_LE(` + vperm C0,C0,C0,LE_MASK +') + + C previous digest combining + vxor C0,C0,D + + C polynomial multiplication + vpmsumd F,H1L,C0 + vpmsumd R,H1M,C0 + + C reduction + vpmsumd T,F,POLY_L + xxswapd VSR(D),VSR(F) + vxor R,R,T + vxor D,R,D + + addi DATA,DATA,0x10 + clrldi LENGTH,LENGTH,60 C 'set the high-order 60 bits to zeros' +Lmod: + C --- process the modulo bytes, padding the low-order bytes with zeros --- + + cmpldi LENGTH,0 + beq Ldone + + C load table elements + li r8,1*TableElemAlign + lxvd2x VSR(H1M),0,TABLE + lxvd2x VSR(H1L),r8,TABLE + + C push every modulo byte to the stack and load them with padding into vector register + vxor ZERO,ZERO,ZERO + addi r8,SP,-16 + stvx ZERO,0,r8 +Lstb_loop: + subic. LENGTH,LENGTH,1 + lbzx r7,LENGTH,DATA + stbx r7,LENGTH,r8 + bne Lstb_loop + lxvd2x VSR(C0),0,r8 + +IF_LE(` + vperm C0,C0,C0,LE_MASK +') + + C previous digest combining + vxor C0,C0,D + + C polynomial multiplication + vpmsumd F,H1L,C0 + vpmsumd R,H1M,C0 + + C reduction + vpmsumd T,F,POLY_L + xxswapd VSR(D),VSR(F) + vxor R,R,T + vxor D,R,D + +Ldone: + C byte-reverse of each doubleword permuting on little-endian mode +IF_LE(` + vperm D,D,D,LE_MASK +') + stxvd2x VSR(D),0,X C store digest 'D' + + blr +EPILOGUE(_nettle_gcm_hash) + +.data + C 0xC2000000000000000000000000000001 +.polynomial: +.align 4 +IF_BE(` +.byte 0xC2 +.rept 14 +.byte 0x00 +.endr +.byte 0x01 +',` +.byte 0x01 +.rept 14 +.byte 0x00 +.endr +.byte 0xC2 +')