/*

* Copyright (c) 2018, Intel Corporation.

*

* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

*

* This code is free software; you can redistribute it and/or modify it

* under the terms of the GNU General Public License version 2 only, as

* published by the Free Software Foundation.

*

* This code 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

* version 2 for more details (a copy is included in the LICENSE file that

* accompanied this code).

*

* You should have received a copy of the GNU General Public License version

* 2 along with this work; if not, write to the Free Software Foundation,

* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

*

* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

* or visit www.oracle.com if you need additional information or have any

* questions.

*

*/

#include "precompiled.hpp"

#include "asm/assembler.hpp"

#include "asm/assembler.inline.hpp"

#include "runtime/stubRoutines.hpp"

#include "macroAssembler_x86.hpp"

// Multiply 128 x 128 bits, using 4 pclmulqdq operations

void MacroAssembler::schoolbookAAD(int i, Register htbl, XMMRegister data,

    XMMRegister tmp0, XMMRegister tmp1, XMMRegister tmp2, XMMRegister tmp3) {

    movdqu(xmm15, Address(htbl, i * 16));

    vpclmulhqlqdq(tmp3, data, xmm15); // 0x01

    vpxor(tmp2, tmp2, tmp3, Assembler::AVX_128bit);

    vpclmulldq(tmp3, data, xmm15); // 0x00

    vpxor(tmp0, tmp0, tmp3, Assembler::AVX_128bit);

    vpclmulhdq(tmp3, data, xmm15); // 0x11

    vpxor(tmp1, tmp1, tmp3, Assembler::AVX_128bit);

    vpclmullqhqdq(tmp3, data, xmm15); // 0x10

    vpxor(tmp2, tmp2, tmp3, Assembler::AVX_128bit);

}

// Multiply two 128 bit numbers resulting in a 256 bit value

// Result of the multiplication followed by reduction stored in state

void MacroAssembler::gfmul(XMMRegister tmp0, XMMRegister state) {

    const XMMRegister tmp1 = xmm4;

    const XMMRegister tmp2 = xmm5;

    const XMMRegister tmp3 = xmm6;

    const XMMRegister tmp4 = xmm7;

    vpclmulldq(tmp1, state, tmp0); //0x00  (a0 * b0)

    vpclmulhdq(tmp4, state, tmp0);//0x11 (a1 * b1)

    vpclmullqhqdq(tmp2, state, tmp0);//0x10 (a1 * b0)

    vpclmulhqlqdq(tmp3, state, tmp0); //0x01 (a0 * b1)

    vpxor(tmp2, tmp2, tmp3, Assembler::AVX_128bit); // (a0 * b1) + (a1 * b0)

    vpslldq(tmp3, tmp2, 8, Assembler::AVX_128bit);

    vpsrldq(tmp2, tmp2, 8, Assembler::AVX_128bit);

    vpxor(tmp1, tmp1, tmp3, Assembler::AVX_128bit); // tmp1 and tmp4 hold the result

    vpxor(tmp4, tmp4, tmp2, Assembler::AVX_128bit); // of carryless multiplication

    // Follows the reduction technique mentioned in

    // Shift-XOR reduction described in Gueron-Kounavis May 2010

    // First phase of reduction

    //

    vpslld(xmm8, tmp1, 31, Assembler::AVX_128bit); // packed right shift shifting << 31

    vpslld(xmm9, tmp1, 30, Assembler::AVX_128bit); // packed right shift shifting << 30

    vpslld(xmm10, tmp1, 25, Assembler::AVX_128bit);// packed right shift shifting << 25

    // xor the shifted versions

    vpxor(xmm8, xmm8, xmm9, Assembler::AVX_128bit);

    vpxor(xmm8, xmm8, xmm10, Assembler::AVX_128bit);

    vpslldq(xmm9, xmm8, 12, Assembler::AVX_128bit);

    vpsrldq(xmm8, xmm8, 4, Assembler::AVX_128bit);

    vpxor(tmp1, tmp1, xmm9, Assembler::AVX_128bit);// first phase of the reduction complete

    //

    // Second phase of the reduction

    //

    vpsrld(xmm9, tmp1, 1, Assembler::AVX_128bit);// packed left shifting >> 1

    vpsrld(xmm10, tmp1, 2, Assembler::AVX_128bit);// packed left shifting >> 2

    vpsrld(xmm11, tmp1, 7, Assembler::AVX_128bit);// packed left shifting >> 7

    vpxor(xmm9, xmm9, xmm10, Assembler::AVX_128bit);// xor the shifted versions

    vpxor(xmm9, xmm9, xmm11, Assembler::AVX_128bit);

    vpxor(xmm9, xmm9, xmm8, Assembler::AVX_128bit);

    vpxor(tmp1, tmp1, xmm9, Assembler::AVX_128bit);

    vpxor(state, tmp4, tmp1, Assembler::AVX_128bit);// the result is in state

    ret(0);

}

// This method takes the subkey after expansion as input and generates 1 * 16 power of subkey H.

// The power of H is used in reduction process for one block ghash

void MacroAssembler::generateHtbl_one_block(Register htbl) {

    const XMMRegister t = xmm13;

    // load the original subkey hash

    movdqu(t, Address(htbl, 0));

    // shuffle using long swap mask

    movdqu(xmm10, ExternalAddress(StubRoutines::x86::ghash_long_swap_mask_addr()));

    vpshufb(t, t, xmm10, Assembler::AVX_128bit);

    // Compute H' = GFMUL(H, 2)

    vpsrld(xmm3, t, 7, Assembler::AVX_128bit);

    movdqu(xmm4, ExternalAddress(StubRoutines::x86::ghash_shufflemask_addr()));

    vpshufb(xmm3, xmm3, xmm4, Assembler::AVX_128bit);

    movl(rax, 0xff00);

    movdl(xmm4, rax);

    vpshufb(xmm4, xmm4, xmm3, Assembler::AVX_128bit);

    movdqu(xmm5, ExternalAddress(StubRoutines::x86::ghash_polynomial_addr()));

    vpand(xmm5, xmm5, xmm4, Assembler::AVX_128bit);

    vpsrld(xmm3, t, 31, Assembler::AVX_128bit);

    vpslld(xmm4, t, 1, Assembler::AVX_128bit);

    vpslldq(xmm3, xmm3, 4, Assembler::AVX_128bit);

    vpxor(t, xmm4, xmm3, Assembler::AVX_128bit);// t holds p(x) <<1 or H * 2

    //Adding p(x)<<1 to xmm5 which holds the reduction polynomial

    vpxor(t, t, xmm5, Assembler::AVX_128bit);

    movdqu(Address(htbl, 1 * 16), t); // H * 2

    ret(0);

}

// This method takes the subkey after expansion as input and generates the remaining powers of subkey H.

// The power of H is used in reduction process for eight block ghash

void MacroAssembler::generateHtbl_eight_blocks(Register htbl) {

    const XMMRegister t = xmm13;

    const XMMRegister tmp0 = xmm1;

    Label GFMUL;

    movdqu(t, Address(htbl, 1 * 16));

    movdqu(tmp0, t);

    // tmp0 and t hold H. Now we compute powers of H by using GFMUL(H, H)

    call(GFMUL, relocInfo::none);

    movdqu(Address(htbl, 2 * 16), t); //H ^ 2 * 2

    call(GFMUL, relocInfo::none);

    movdqu(Address(htbl, 3 * 16), t); //H ^ 3 * 2

    call(GFMUL, relocInfo::none);

    movdqu(Address(htbl, 4 * 16), t); //H ^ 4 * 2

    call(GFMUL, relocInfo::none);

    movdqu(Address(htbl, 5 * 16), t); //H ^ 5 * 2

    call(GFMUL, relocInfo::none);

    movdqu(Address(htbl, 6 * 16), t); //H ^ 6 * 2

    call(GFMUL, relocInfo::none);

    movdqu(Address(htbl, 7 * 16), t); //H ^ 7 * 2

    call(GFMUL, relocInfo::none);

    movdqu(Address(htbl, 8 * 16), t); //H ^ 8 * 2

    ret(0);

    bind(GFMUL);

    gfmul(tmp0, t);

}

// Multiblock and single block GHASH computation using Shift XOR reduction technique

void MacroAssembler::avx_ghash(Register input_state, Register htbl,

    Register input_data, Register blocks) {

    // temporary variables to hold input data and input state

    const XMMRegister data = xmm1;

    const XMMRegister state = xmm0;

    // temporary variables to hold intermediate results

    const XMMRegister tmp0 = xmm3;

    const XMMRegister tmp1 = xmm4;

    const XMMRegister tmp2 = xmm5;

    const XMMRegister tmp3 = xmm6;

    // temporary variables to hold byte and long swap masks

    const XMMRegister bswap_mask = xmm2;

    const XMMRegister lswap_mask = xmm14;

    Label GENERATE_HTBL_1_BLK, GENERATE_HTBL_8_BLKS, BEGIN_PROCESS, GFMUL, BLOCK8_REDUCTION,

          ONE_BLK_INIT, PROCESS_1_BLOCK, PROCESS_8_BLOCKS, SAVE_STATE, EXIT_GHASH;

    testptr(blocks, blocks);

    jcc(Assembler::zero, EXIT_GHASH);

    // Check if Hashtable (1*16) has been already generated

    // For anything less than 8 blocks, we generate only the first power of H.

    movdqu(tmp2, Address(htbl, 1 * 16));

    ptest(tmp2, tmp2);

    jcc(Assembler::notZero, BEGIN_PROCESS);

    call(GENERATE_HTBL_1_BLK, relocInfo::none);

    // Shuffle the input state

    bind(BEGIN_PROCESS);

    movdqu(lswap_mask, ExternalAddress(StubRoutines::x86::ghash_long_swap_mask_addr()));

    movdqu(state, Address(input_state, 0));

    vpshufb(state, state, lswap_mask, Assembler::AVX_128bit);

    cmpl(blocks, 8);

    jcc(Assembler::below, ONE_BLK_INIT);

    // If we have 8 blocks or more data, then generate remaining powers of H

    movdqu(tmp2, Address(htbl, 8 * 16));

    ptest(tmp2, tmp2);

    jcc(Assembler::notZero, PROCESS_8_BLOCKS);

    call(GENERATE_HTBL_8_BLKS, relocInfo::none);

    //Do 8 multiplies followed by a reduction processing 8 blocks of data at a time

    //Each block = 16 bytes.

    bind(PROCESS_8_BLOCKS);

    subl(blocks, 8);

    movdqu(bswap_mask, ExternalAddress(StubRoutines::x86::ghash_byte_swap_mask_addr()));

    movdqu(data, Address(input_data, 16 * 7));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    //Loading 1*16 as calculated powers of H required starts at that location.

    movdqu(xmm15, Address(htbl, 1 * 16));

    //Perform carryless multiplication of (H*2, data block #7)

    vpclmulhqlqdq(tmp2, data, xmm15);//a0 * b1

    vpclmulldq(tmp0, data, xmm15);//a0 * b0

    vpclmulhdq(tmp1, data, xmm15);//a1 * b1

    vpclmullqhqdq(tmp3, data, xmm15);//a1* b0

    vpxor(tmp2, tmp2, tmp3, Assembler::AVX_128bit);// (a0 * b1) + (a1 * b0)

    movdqu(data, Address(input_data, 16 * 6));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    // Perform carryless multiplication of (H^2 * 2, data block #6)

    schoolbookAAD(2, htbl, data, tmp0, tmp1, tmp2, tmp3);

    movdqu(data, Address(input_data, 16 * 5));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    // Perform carryless multiplication of (H^3 * 2, data block #5)

    schoolbookAAD(3, htbl, data, tmp0, tmp1, tmp2, tmp3);

    movdqu(data, Address(input_data, 16 * 4));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    // Perform carryless multiplication of (H^4 * 2, data block #4)

    schoolbookAAD(4, htbl, data, tmp0, tmp1, tmp2, tmp3);

    movdqu(data, Address(input_data, 16 * 3));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    // Perform carryless multiplication of (H^5 * 2, data block #3)

    schoolbookAAD(5, htbl, data, tmp0, tmp1, tmp2, tmp3);

    movdqu(data, Address(input_data, 16 * 2));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    // Perform carryless multiplication of (H^6 * 2, data block #2)

    schoolbookAAD(6, htbl, data, tmp0, tmp1, tmp2, tmp3);

    movdqu(data, Address(input_data, 16 * 1));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    // Perform carryless multiplication of (H^7 * 2, data block #1)

    schoolbookAAD(7, htbl, data, tmp0, tmp1, tmp2, tmp3);

    movdqu(data, Address(input_data, 16 * 0));

    // xor data block#0 with input state before perfoming carry-less multiplication

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    vpxor(data, data, state, Assembler::AVX_128bit);

    // Perform carryless multiplication of (H^8 * 2, data block #0)

    schoolbookAAD(8, htbl, data, tmp0, tmp1, tmp2, tmp3);

    vpslldq(tmp3, tmp2, 8, Assembler::AVX_128bit);

    vpsrldq(tmp2, tmp2, 8, Assembler::AVX_128bit);

    vpxor(tmp0, tmp0, tmp3, Assembler::AVX_128bit);// tmp0, tmp1 contains aggregated results of

    vpxor(tmp1, tmp1, tmp2, Assembler::AVX_128bit);// the multiplication operation

    // we have the 2 128-bit partially accumulated multiplication results in tmp0:tmp1

    // with higher 128-bit in tmp1 and lower 128-bit in corresponding tmp0

    // Follows the reduction technique mentioned in

    // Shift-XOR reduction described in Gueron-Kounavis May 2010

    bind(BLOCK8_REDUCTION);

    // First Phase of the reduction

    vpslld(xmm8, tmp0, 31, Assembler::AVX_128bit); // packed right shifting << 31

    vpslld(xmm9, tmp0, 30, Assembler::AVX_128bit); // packed right shifting << 30

    vpslld(xmm10, tmp0, 25, Assembler::AVX_128bit); // packed right shifting << 25

    // xor the shifted versions

    vpxor(xmm8, xmm8, xmm10, Assembler::AVX_128bit);

    vpxor(xmm8, xmm8, xmm9, Assembler::AVX_128bit);

    vpslldq(xmm9, xmm8, 12, Assembler::AVX_128bit);

    vpsrldq(xmm8, xmm8, 4, Assembler::AVX_128bit);

    vpxor(tmp0, tmp0, xmm9, Assembler::AVX_128bit); // first phase of reduction is complete

    // second phase of the reduction

    vpsrld(xmm9, tmp0, 1, Assembler::AVX_128bit); // packed left shifting >> 1

    vpsrld(xmm10, tmp0, 2, Assembler::AVX_128bit); // packed left shifting >> 2

    vpsrld(tmp2, tmp0, 7, Assembler::AVX_128bit); // packed left shifting >> 7

    // xor the shifted versions

    vpxor(xmm9, xmm9, xmm10, Assembler::AVX_128bit);

    vpxor(xmm9, xmm9, tmp2, Assembler::AVX_128bit);

    vpxor(xmm9, xmm9, xmm8, Assembler::AVX_128bit);

    vpxor(tmp0, xmm9, tmp0, Assembler::AVX_128bit);

    // Final result is in state

    vpxor(state, tmp0, tmp1, Assembler::AVX_128bit);

    lea(input_data, Address(input_data, 16 * 8));

    cmpl(blocks, 8);

    jcc(Assembler::below, ONE_BLK_INIT);

    jmp(PROCESS_8_BLOCKS);

    // Since this is one block operation we will only use H * 2 i.e. the first power of H

    bind(ONE_BLK_INIT);

    movdqu(tmp0, Address(htbl, 1 * 16));

    movdqu(bswap_mask, ExternalAddress(StubRoutines::x86::ghash_byte_swap_mask_addr()));

    //Do one (128 bit x 128 bit) carry-less multiplication at a time followed by a reduction.

    bind(PROCESS_1_BLOCK);

    cmpl(blocks, 0);

    jcc(Assembler::equal, SAVE_STATE);

    subl(blocks, 1);

    movdqu(data, Address(input_data, 0));

    vpshufb(data, data, bswap_mask, Assembler::AVX_128bit);

    vpxor(state, state, data, Assembler::AVX_128bit);

    // gfmul(H*2, state)

    call(GFMUL, relocInfo::none);

    addptr(input_data, 16);

    jmp(PROCESS_1_BLOCK);

    bind(SAVE_STATE);

    vpshufb(state, state, lswap_mask, Assembler::AVX_128bit);

    movdqu(Address(input_state, 0), state);

    jmp(EXIT_GHASH);

    bind(GFMUL);

    gfmul(tmp0, state);

    bind(GENERATE_HTBL_1_BLK);

    generateHtbl_one_block(htbl);

    bind(GENERATE_HTBL_8_BLKS);

    generateHtbl_eight_blocks(htbl);

    bind(EXIT_GHASH);

    // zero out xmm registers used for Htbl storage

    vpxor(xmm0, xmm0, xmm0, Assembler::AVX_128bit);

    vpxor(xmm1, xmm1, xmm1, Assembler::AVX_128bit);

    vpxor(xmm3, xmm3, xmm3, Assembler::AVX_128bit);

    vpxor(xmm15, xmm15, xmm15, Assembler::AVX_128bit);