/* SPDX-License-Identifier: Apache-2.0 OR BSD-2-Clause */
//
// This file is dual-licensed, meaning that you can use it under your
// choice of either of the following two licenses:
//
// Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
//
// Licensed under the Apache License 2.0 (the "License"). You can obtain
// a copy in the file LICENSE in the source distribution or at
// https://www.openssl.org/source/license.html
//
// or
//
// Copyright (c) 2023, Christoph Müllner <christoph.muellner@vrull.eu>
// Copyright (c) 2023, Phoebe Chen <phoebe.chen@sifive.com>
// Copyright 2024 Google LLC
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// The generated code of this file depends on the following RISC-V extensions:
// - RV64I
// - RISC-V Vector ('V') with VLEN >= 128
// - RISC-V Vector SHA-2 Secure Hash extension ('Zvknhb')
// - RISC-V Vector Cryptography Bit-manipulation extension ('Zvkb')

#include <linux/linkage.h>

.text
.option arch, +zvknhb, +zvkb

#define STATEP          a0
#define DATA            a1
#define NUM_BLOCKS      a2

#define STATEP_C        a3
#define K               a4

#define MASK            v0
#define INDICES         v1
#define W0              v10     // LMUL=2
#define W1              v12     // LMUL=2
#define W2              v14     // LMUL=2
#define W3              v16     // LMUL=2
#define VTMP            v20     // LMUL=2
#define FEBA            v22     // LMUL=2
#define HGDC            v24     // LMUL=2
#define PREV_FEBA       v26     // LMUL=2
#define PREV_HGDC       v28     // LMUL=2

// Do 4 rounds of SHA-512.  w0 contains the current 4 message schedule words.
//
// If not all the message schedule words have been computed yet, then this also
// computes 4 more message schedule words.  w1-w3 contain the next 3 groups of 4
// message schedule words; this macro computes the group after w3 and writes it
// to w0.  This means that the next (w0, w1, w2, w3) is the current (w1, w2, w3,
// w0), so the caller must cycle through the registers accordingly.
.macro  sha512_4rounds  last, w0, w1, w2, w3
        vle64.v         VTMP, (K)
        addi            K, K, 32
        vadd.vv         VTMP, VTMP, \w0
        vsha2cl.vv      HGDC, FEBA, VTMP
        vsha2ch.vv      FEBA, HGDC, VTMP
.if !\last
        vmerge.vvm      VTMP, \w2, \w1, MASK
        vsha2ms.vv      \w0, VTMP, \w3
.endif
.endm

.macro  sha512_16rounds last
        sha512_4rounds  \last, W0, W1, W2, W3
        sha512_4rounds  \last, W1, W2, W3, W0
        sha512_4rounds  \last, W2, W3, W0, W1
        sha512_4rounds  \last, W3, W0, W1, W2
.endm

// void sha512_transform_zvknhb_zvkb(struct sha512_block_state *state,
//                                   const u8 *data, size_t nblocks);
SYM_FUNC_START(sha512_transform_zvknhb_zvkb)

        // Setup mask for the vmerge to replace the first word (idx==0) in
        // message scheduling.  There are 4 words, so an 8-bit mask suffices.
        vsetivli        zero, 1, e8, m1, ta, ma
        vmv.v.i         MASK, 0x01

        // Load the state.  The state is stored as {a,b,c,d,e,f,g,h}, but we
        // need {f,e,b,a},{h,g,d,c}.  The dst vtype is e64m2 and the index vtype
        // is e8mf4.  We use index-load with the i8 indices {40, 32, 8, 0},
        // loaded using the 32-bit little endian value 0x00082028.
        li              t0, 0x00082028
        vsetivli        zero, 1, e32, m1, ta, ma
        vmv.v.x         INDICES, t0
        addi            STATEP_C, STATEP, 16
        vsetivli        zero, 4, e64, m2, ta, ma
        vluxei8.v       FEBA, (STATEP), INDICES
        vluxei8.v       HGDC, (STATEP_C), INDICES

.Lnext_block:
        la              K, K512
        addi            NUM_BLOCKS, NUM_BLOCKS, -1

        // Save the previous state, as it's needed later.
        vmv.v.v         PREV_FEBA, FEBA
        vmv.v.v         PREV_HGDC, HGDC

        // Load the next 1024-bit message block and endian-swap each 64-bit word
        vle64.v         W0, (DATA)
        vrev8.v         W0, W0
        addi            DATA, DATA, 32
        vle64.v         W1, (DATA)
        vrev8.v         W1, W1
        addi            DATA, DATA, 32
        vle64.v         W2, (DATA)
        vrev8.v         W2, W2
        addi            DATA, DATA, 32
        vle64.v         W3, (DATA)
        vrev8.v         W3, W3
        addi            DATA, DATA, 32

        // Do the 80 rounds of SHA-512.
        sha512_16rounds 0
        sha512_16rounds 0
        sha512_16rounds 0
        sha512_16rounds 0
        sha512_16rounds 1

        // Add the previous state.
        vadd.vv         FEBA, FEBA, PREV_FEBA
        vadd.vv         HGDC, HGDC, PREV_HGDC

        // Repeat if more blocks remain.
        bnez            NUM_BLOCKS, .Lnext_block

        // Store the new state and return.
        vsuxei8.v       FEBA, (STATEP), INDICES
        vsuxei8.v       HGDC, (STATEP_C), INDICES
        ret
SYM_FUNC_END(sha512_transform_zvknhb_zvkb)

.section ".rodata"
.p2align 3
.type K512, @object
K512:
        .dword          0x428a2f98d728ae22, 0x7137449123ef65cd
        .dword          0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc
        .dword          0x3956c25bf348b538, 0x59f111f1b605d019
        .dword          0x923f82a4af194f9b, 0xab1c5ed5da6d8118
        .dword          0xd807aa98a3030242, 0x12835b0145706fbe
        .dword          0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2
        .dword          0x72be5d74f27b896f, 0x80deb1fe3b1696b1
        .dword          0x9bdc06a725c71235, 0xc19bf174cf692694
        .dword          0xe49b69c19ef14ad2, 0xefbe4786384f25e3
        .dword          0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65
        .dword          0x2de92c6f592b0275, 0x4a7484aa6ea6e483
        .dword          0x5cb0a9dcbd41fbd4, 0x76f988da831153b5
        .dword          0x983e5152ee66dfab, 0xa831c66d2db43210
        .dword          0xb00327c898fb213f, 0xbf597fc7beef0ee4
        .dword          0xc6e00bf33da88fc2, 0xd5a79147930aa725
        .dword          0x06ca6351e003826f, 0x142929670a0e6e70
        .dword          0x27b70a8546d22ffc, 0x2e1b21385c26c926
        .dword          0x4d2c6dfc5ac42aed, 0x53380d139d95b3df
        .dword          0x650a73548baf63de, 0x766a0abb3c77b2a8
        .dword          0x81c2c92e47edaee6, 0x92722c851482353b
        .dword          0xa2bfe8a14cf10364, 0xa81a664bbc423001
        .dword          0xc24b8b70d0f89791, 0xc76c51a30654be30
        .dword          0xd192e819d6ef5218, 0xd69906245565a910
        .dword          0xf40e35855771202a, 0x106aa07032bbd1b8
        .dword          0x19a4c116b8d2d0c8, 0x1e376c085141ab53
        .dword          0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8
        .dword          0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb
        .dword          0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3
        .dword          0x748f82ee5defb2fc, 0x78a5636f43172f60
        .dword          0x84c87814a1f0ab72, 0x8cc702081a6439ec
        .dword          0x90befffa23631e28, 0xa4506cebde82bde9
        .dword          0xbef9a3f7b2c67915, 0xc67178f2e372532b
        .dword          0xca273eceea26619c, 0xd186b8c721c0c207
        .dword          0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178
        .dword          0x06f067aa72176fba, 0x0a637dc5a2c898a6
        .dword          0x113f9804bef90dae, 0x1b710b35131c471b
        .dword          0x28db77f523047d84, 0x32caab7b40c72493
        .dword          0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c
        .dword          0x4cc5d4becb3e42b6, 0x597f299cfc657e2a
        .dword          0x5fcb6fab3ad6faec, 0x6c44198c4a475817
.size K512, . - K512