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[v4,0/4] Implement GCM ghash using Zbc and Zbkb extensions

Message ID 20230329140642.2186644-1-heiko.stuebner@vrull.eu
Headers show
Series Implement GCM ghash using Zbc and Zbkb extensions | expand

Message

Heiko Stübner March 29, 2023, 2:06 p.m. UTC 
From: Heiko Stuebner <heiko.stuebner@vrull.eu>

This was originally part of my vector crypto series, but was part
of a separate openssl merge request implementing GCM ghash as using
non-vector extensions.

As that pull-request
    https://github.com/openssl/openssl/pull/20078
got merged recently into openssl, we could also check if this could
go into the kernel as well and provide a base for further accelerated
cryptographic support.


Changes in v4:
- rebase on top of riscv/for-next
- split out the scalar crypto implementation from the vector series
- refresh code from openSSL to match exactly
- Remove RFC label, as Zbc and Zbkb are ratified and
  the cryptographic code was merged into openSSL

changes in v3:
- rebase on top of 6.3-rc2
- rebase on top of vector-v14 patchset
- add the missing Co-developed-by mentions to showcase
  the people that did the actual openSSL crypto code

changes in v2:
- rebased on 6.2 + zbb series, so don't include already
  applied changes anymore
- refresh code picked from openssl as that side matures
- more algorithms (SHA512, AES, SM3, SM4)

Heiko Stuebner (4):
  RISC-V: add Zbc extension detection
  RISC-V: add Zbkb extension detection
  RISC-V: hook new crypto subdir into build-system
  RISC-V: crypto: add accelerated GCM GHASH implementation

 arch/riscv/Kbuild                      |   1 +
 arch/riscv/Kconfig                     |  22 ++
 arch/riscv/crypto/Kconfig              |  18 ++
 arch/riscv/crypto/Makefile             |  18 ++
 arch/riscv/crypto/ghash-riscv64-glue.c | 258 ++++++++++++++++
 arch/riscv/crypto/ghash-riscv64-zbc.pl | 400 +++++++++++++++++++++++++
 arch/riscv/crypto/riscv.pm             | 231 ++++++++++++++
 arch/riscv/include/asm/hwcap.h         |   2 +
 arch/riscv/kernel/cpu.c                |   2 +
 arch/riscv/kernel/cpufeature.c         |   2 +
 crypto/Kconfig                         |   3 +
 11 files changed, 957 insertions(+)
 create mode 100644 arch/riscv/crypto/Kconfig
 create mode 100644 arch/riscv/crypto/Makefile
 create mode 100644 arch/riscv/crypto/ghash-riscv64-glue.c
 create mode 100644 arch/riscv/crypto/ghash-riscv64-zbc.pl
 create mode 100644 arch/riscv/crypto/riscv.pm

Comments

Nathan Huckleberry April 11, 2023, 3 p.m. UTC | #1 
Hey Heiko,

Thanks for the patch, it generally looks good. A few comments.

On Wed, Mar 29, 2023 at 7:08 AM Heiko Stuebner <heiko@sntech.de> wrote:
>
> From: Heiko Stuebner <heiko.stuebner@vrull.eu>
>
> With different sets of available extensions a number of different
> implementation variants are possible. Quite a number of them are already
> implemented in openSSL or are in the process of being implemented, so pick
> the relevant openSSL coden and add suitable glue code similar to arm64 and
> powerpc to use it for kernel-specific cryptography.
>
> The prioritization of the algorithms follows the ifdef chain for the
> assembly callbacks done in openssl but here algorithms will get registered
> separately so that all of them can be part of the crypto selftests.
>
> The crypto subsystem will select the most performant of all registered
> algorithms on the running system but will selftest all registered ones.
>
> In a first step this adds scalar variants using the Zbc, Zbb and
> possible Zbkb (bitmanip crypto extension) and the perl implementation
> stems from openSSL pull request on
>     https://github.com/openssl/openssl/pull/20078
>
> Co-developed-by: Christoph Müllner <christoph.muellner@vrull.eu>
> Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
> ---
>  arch/riscv/crypto/Kconfig              |  13 +
>  arch/riscv/crypto/Makefile             |  14 +
>  arch/riscv/crypto/ghash-riscv64-glue.c | 258 ++++++++++++++++
>  arch/riscv/crypto/ghash-riscv64-zbc.pl | 400 +++++++++++++++++++++++++
>  arch/riscv/crypto/riscv.pm             | 231 ++++++++++++++
>  5 files changed, 916 insertions(+)
>  create mode 100644 arch/riscv/crypto/ghash-riscv64-glue.c
>  create mode 100644 arch/riscv/crypto/ghash-riscv64-zbc.pl
>  create mode 100644 arch/riscv/crypto/riscv.pm
>
> diff --git a/arch/riscv/crypto/Kconfig b/arch/riscv/crypto/Kconfig
> index 10d60edc0110..cd2237923e68 100644
> --- a/arch/riscv/crypto/Kconfig
> +++ b/arch/riscv/crypto/Kconfig
> @@ -2,4 +2,17 @@
>
>  menu "Accelerated Cryptographic Algorithms for CPU (riscv)"
>
> +config CRYPTO_GHASH_RISCV64
> +       tristate "Hash functions: GHASH"
> +       depends on 64BIT && RISCV_ISA_ZBC
> +       select CRYPTO_HASH
> +       select CRYPTO_LIB_GF128MUL
> +       help
> +         GCM GHASH function (NIST SP800-38D)
> +
> +         Architecture: riscv64 using one of:
> +         - Zbc extension
> +         - Zbc + Zbb extensions
> +         - Zbc + Zbkb extensions
> +
>  endmenu
> diff --git a/arch/riscv/crypto/Makefile b/arch/riscv/crypto/Makefile
> index b3b6332c9f6d..0a158919e9da 100644
> --- a/arch/riscv/crypto/Makefile
> +++ b/arch/riscv/crypto/Makefile
> @@ -2,3 +2,17 @@
>  #
>  # linux/arch/riscv/crypto/Makefile
>  #
> +
> +obj-$(CONFIG_CRYPTO_GHASH_RISCV64) += ghash-riscv64.o
> +ghash-riscv64-y := ghash-riscv64-glue.o
> +ifdef CONFIG_RISCV_ISA_ZBC
> +ghash-riscv64-y += ghash-riscv64-zbc.o
> +endif
> +
> +quiet_cmd_perlasm = PERLASM $@
> +      cmd_perlasm = $(PERL) $(<) void $(@)
> +
> +$(obj)/ghash-riscv64-zbc.S: $(src)/ghash-riscv64-zbc.pl
> +       $(call cmd,perlasm)
> +
> +clean-files += ghash-riscv64-zbc.S
> diff --git a/arch/riscv/crypto/ghash-riscv64-glue.c b/arch/riscv/crypto/ghash-riscv64-glue.c
> new file mode 100644
> index 000000000000..5ab704c49539
> --- /dev/null
> +++ b/arch/riscv/crypto/ghash-riscv64-glue.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * RISC-V optimized GHASH routines
> + *
> + * Copyright (C) 2023 VRULL GmbH
> + * Author: Heiko Stuebner <heiko.stuebner@vrull.eu>
> + */
> +
> +#include <linux/types.h>
> +#include <linux/err.h>
> +#include <linux/crypto.h>
> +#include <linux/module.h>
> +#include <asm/simd.h>
> +#include <crypto/ghash.h>
> +#include <crypto/internal/hash.h>
> +#include <crypto/internal/simd.h>
> +
> +/* Zbc (optional with zbkb improvements) */
> +void gcm_ghash_rv64i_zbc(u64 Xi[2], const u128 Htable[16],
> +                        const u8 *inp, size_t len);
> +void gcm_ghash_rv64i_zbc__zbkb(u64 Xi[2], const u128 Htable[16],
> +                              const u8 *inp, size_t len);
> +
> +struct riscv64_ghash_ctx {
> +       void (*ghash_func)(u64 Xi[2], const u128 Htable[16],
> +                          const u8 *inp, size_t len);
> +
> +       /* key used by vector asm */
> +       u128 htable[16];

This field looks too big. The assembly only loads the first 128-byte
value from this table.

Is this copied from another implementation? There's an optimization
where you precompute the first N powers of H so that you can perform 1
finite field reduction for every N multiplications, but it doesn't
look like that's being used here.

> +       /* key used by software fallback */
> +       be128 key;
> +};
> +
> +struct riscv64_ghash_desc_ctx {
> +       u64 shash[2];
> +       u8 buffer[GHASH_DIGEST_SIZE];
> +       int bytes;
> +};
> +
> +static int riscv64_ghash_init(struct shash_desc *desc)
> +{
> +       struct riscv64_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
> +
> +       dctx->bytes = 0;
> +       memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
> +       return 0;
> +}
> +
> +#ifdef CONFIG_RISCV_ISA_ZBC
> +
> +#define RISCV64_ZBC_SETKEY(VARIANT, GHASH)                             \
> +void gcm_init_rv64i_ ## VARIANT(u128 Htable[16], const u64 Xi[2]);     \
> +static int riscv64_zbc_ghash_setkey_ ## VARIANT(struct crypto_shash *tfm,      \
> +                                          const u8 *key,               \
> +                                          unsigned int keylen)         \
> +{                                                                      \
> +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm)); \
> +       const u64 k[2] = { cpu_to_be64(((const u64 *)key)[0]),          \
> +                          cpu_to_be64(((const u64 *)key)[1]) };        \
> +                                                                       \
> +       if (keylen != GHASH_BLOCK_SIZE)                                 \
> +               return -EINVAL;                                         \
> +                                                                       \
> +       memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);                       \
> +       gcm_init_rv64i_ ## VARIANT(ctx->htable, k);                     \
> +                                                                       \
> +       ctx->ghash_func = gcm_ghash_rv64i_ ## GHASH;                    \
> +                                                                       \
> +       return 0;                                                       \
> +}

I'd prefer three identical functions over a macro here. Code searching
tools and compiler warnings are significantly worse with macros.

> +
> +static int riscv64_zbc_ghash_update(struct shash_desc *desc,
> +                          const u8 *src, unsigned int srclen)
> +{
> +       unsigned int len;
> +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
> +       struct riscv64_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
> +
> +       if (dctx->bytes) {
> +               if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
> +                       memcpy(dctx->buffer + dctx->bytes, src,
> +                               srclen);
> +                       dctx->bytes += srclen;
> +                       return 0;
> +               }
> +               memcpy(dctx->buffer + dctx->bytes, src,
> +                       GHASH_DIGEST_SIZE - dctx->bytes);
> +
> +               ctx->ghash_func(dctx->shash, ctx->htable,
> +                               dctx->buffer, GHASH_DIGEST_SIZE);
> +
> +               src += GHASH_DIGEST_SIZE - dctx->bytes;
> +               srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
> +               dctx->bytes = 0;
> +       }
> +       len = srclen & ~(GHASH_DIGEST_SIZE - 1);
> +
> +       if (len) {
> +               gcm_ghash_rv64i_zbc(dctx->shash, ctx->htable,
> +                               src, len);
> +               src += len;
> +               srclen -= len;
> +       }
> +
> +       if (srclen) {
> +               memcpy(dctx->buffer, src, srclen);
> +               dctx->bytes = srclen;
> +       }
> +       return 0;
> +}
> +
> +static int riscv64_zbc_ghash_final(struct shash_desc *desc, u8 *out)
> +{
> +       int i;
> +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
> +       struct riscv64_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
> +
> +       if (dctx->bytes) {
> +               for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
> +                       dctx->buffer[i] = 0;
> +               ctx->ghash_func(dctx->shash, ctx->htable,
> +                               dctx->buffer, GHASH_DIGEST_SIZE);

Can we do this without an indirect call?

> +               dctx->bytes = 0;
> +       }
> +       memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
> +       return 0;
> +}
> +
> +RISCV64_ZBC_SETKEY(zbc, zbc);
> +struct shash_alg riscv64_zbc_ghash_alg = {
> +       .digestsize = GHASH_DIGEST_SIZE,
> +       .init = riscv64_ghash_init,
> +       .update = riscv64_zbc_ghash_update,
> +       .final = riscv64_zbc_ghash_final,
> +       .setkey = riscv64_zbc_ghash_setkey_zbc,
> +       .descsize = sizeof(struct riscv64_ghash_desc_ctx)
> +                   + sizeof(struct ghash_desc_ctx),
> +       .base = {
> +                .cra_name = "ghash",
> +                .cra_driver_name = "riscv64_zbc_ghash",
> +                .cra_priority = 250,
> +                .cra_blocksize = GHASH_BLOCK_SIZE,
> +                .cra_ctxsize = sizeof(struct riscv64_ghash_ctx),
> +                .cra_module = THIS_MODULE,
> +       },
> +};
> +
> +RISCV64_ZBC_SETKEY(zbc__zbb, zbc);
> +struct shash_alg riscv64_zbc_zbb_ghash_alg = {
> +       .digestsize = GHASH_DIGEST_SIZE,
> +       .init = riscv64_ghash_init,
> +       .update = riscv64_zbc_ghash_update,
> +       .final = riscv64_zbc_ghash_final,
> +       .setkey = riscv64_zbc_ghash_setkey_zbc__zbb,
> +       .descsize = sizeof(struct riscv64_ghash_desc_ctx)
> +                   + sizeof(struct ghash_desc_ctx),
> +       .base = {
> +                .cra_name = "ghash",
> +                .cra_driver_name = "riscv64_zbc_zbb_ghash",
> +                .cra_priority = 251,
> +                .cra_blocksize = GHASH_BLOCK_SIZE,
> +                .cra_ctxsize = sizeof(struct riscv64_ghash_ctx),
> +                .cra_module = THIS_MODULE,
> +       },
> +};
> +
> +RISCV64_ZBC_SETKEY(zbc__zbkb, zbc__zbkb);
> +struct shash_alg riscv64_zbc_zbkb_ghash_alg = {
> +       .digestsize = GHASH_DIGEST_SIZE,
> +       .init = riscv64_ghash_init,
> +       .update = riscv64_zbc_ghash_update,
> +       .final = riscv64_zbc_ghash_final,
> +       .setkey = riscv64_zbc_ghash_setkey_zbc__zbkb,
> +       .descsize = sizeof(struct riscv64_ghash_desc_ctx)
> +                   + sizeof(struct ghash_desc_ctx),
> +       .base = {
> +                .cra_name = "ghash",
> +                .cra_driver_name = "riscv64_zbc_zbkb_ghash",
> +                .cra_priority = 252,
> +                .cra_blocksize = GHASH_BLOCK_SIZE,
> +                .cra_ctxsize = sizeof(struct riscv64_ghash_ctx),
> +                .cra_module = THIS_MODULE,
> +       },
> +};
> +
> +#endif /* CONFIG_RISCV_ISA_ZBC */
> +
> +#define RISCV64_DEFINED_GHASHES                7
> +
> +static struct shash_alg *riscv64_ghashes[RISCV64_DEFINED_GHASHES];
> +static int num_riscv64_ghashes;
> +
> +static int __init riscv64_ghash_register(struct shash_alg *ghash)
> +{
> +       int ret;
> +
> +       ret = crypto_register_shash(ghash);
> +       if (ret < 0) {
> +               int i;
> +
> +               for (i = num_riscv64_ghashes - 1; i >= 0 ; i--)
> +                       crypto_unregister_shash(riscv64_ghashes[i]);
> +
> +               num_riscv64_ghashes = 0;
> +
> +               return ret;
> +       }
> +
> +       pr_debug("Registered RISC-V ghash %s\n", ghash->base.cra_driver_name);
> +       riscv64_ghashes[num_riscv64_ghashes] = ghash;
> +       num_riscv64_ghashes++;
> +       return 0;
> +}
> +
> +static int __init riscv64_ghash_mod_init(void)
> +{
> +       int ret = 0;
> +
> +#ifdef CONFIG_RISCV_ISA_ZBC
> +       if (riscv_isa_extension_available(NULL, ZBC)) {
> +               ret = riscv64_ghash_register(&riscv64_zbc_ghash_alg);
> +               if (ret < 0)
> +                       return ret;
> +
> +               if (riscv_isa_extension_available(NULL, ZBB)) {
> +                       ret = riscv64_ghash_register(&riscv64_zbc_zbb_ghash_alg);
> +                       if (ret < 0)
> +                               return ret;
> +               }
> +
> +               if (riscv_isa_extension_available(NULL, ZBKB)) {
> +                       ret = riscv64_ghash_register(&riscv64_zbc_zbkb_ghash_alg);
> +                       if (ret < 0)
> +                               return ret;
> +               }
> +       }
> +#endif
> +
> +       return 0;
> +}
> +
> +static void __exit riscv64_ghash_mod_fini(void)
> +{
> +       int i;
> +
> +       for (i = num_riscv64_ghashes - 1; i >= 0 ; i--)
> +               crypto_unregister_shash(riscv64_ghashes[i]);
> +
> +       num_riscv64_ghashes = 0;
> +}
> +
> +module_init(riscv64_ghash_mod_init);
> +module_exit(riscv64_ghash_mod_fini);
> +
> +MODULE_DESCRIPTION("GSM GHASH (accelerated)");
> +MODULE_AUTHOR("Heiko Stuebner <heiko.stuebner@vrull.eu>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS_CRYPTO("ghash");
> diff --git a/arch/riscv/crypto/ghash-riscv64-zbc.pl b/arch/riscv/crypto/ghash-riscv64-zbc.pl
> new file mode 100644
> index 000000000000..691231ffa11c
> --- /dev/null
> +++ b/arch/riscv/crypto/ghash-riscv64-zbc.pl
> @@ -0,0 +1,400 @@
> +#! /usr/bin/env perl
> +# Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
> +#
> +# Licensed under the Apache License 2.0 (the "License").  You may not use
> +# this file except in compliance with the License.  You can obtain a copy
> +# in the file LICENSE in the source distribution or at
> +# https://www.openssl.org/source/license.html
> +
> +use strict;
> +use warnings;
> +
> +use FindBin qw($Bin);
> +use lib "$Bin";
> +use lib "$Bin/../../perlasm";
> +use riscv;
> +
> +# $output is the last argument if it looks like a file (it has an extension)
> +# $flavour is the first argument if it doesn't look like a file
> +my $output = $#ARGV >= 0 && $ARGV[$#ARGV] =~ m|\.\w+$| ? pop : undef;
> +my $flavour = $#ARGV >= 0 && $ARGV[0] !~ m|\.| ? shift : undef;
> +
> +$output and open STDOUT,">$output";
> +
> +my $code=<<___;
> +.text
> +___
> +
> +################################################################################
> +# void gcm_init_rv64i_zbc(u128 Htable[16], const u64 H[2]);
> +# void gcm_init_rv64i_zbc__zbb(u128 Htable[16], const u64 H[2]);
> +# void gcm_init_rv64i_zbc__zbkb(u128 Htable[16], const u64 H[2]);
> +#
> +# input:  H: 128-bit H - secret parameter E(K, 0^128)
> +# output: Htable: Preprocessed key data for gcm_gmult_rv64i_zbc* and
> +#                 gcm_ghash_rv64i_zbc*
> +#
> +# All callers of this function revert the byte-order unconditionally
> +# on little-endian machines. So we need to revert the byte-order back.
> +# Additionally we reverse the bits of each byte.
> +
> +{
> +my ($Htable,$H,$VAL0,$VAL1,$TMP0,$TMP1,$TMP2) = ("a0","a1","a2","a3","t0","t1","t2");
> +
> +$code .= <<___;
> +.p2align 3
> +.globl gcm_init_rv64i_zbc
> +.type gcm_init_rv64i_zbc,\@function
> +gcm_init_rv64i_zbc:
> +    ld      $VAL0,0($H)
> +    ld      $VAL1,8($H)
> +    @{[brev8_rv64i   $VAL0, $TMP0, $TMP1, $TMP2]}
> +    @{[brev8_rv64i   $VAL1, $TMP0, $TMP1, $TMP2]}
> +    @{[sd_rev8_rv64i $VAL0, $Htable, 0, $TMP0]}
> +    @{[sd_rev8_rv64i $VAL1, $Htable, 8, $TMP0]}
> +    ret
> +.size gcm_init_rv64i_zbc,.-gcm_init_rv64i_zbc
> +___
> +}
> +
> +{
> +my ($Htable,$H,$VAL0,$VAL1,$TMP0,$TMP1,$TMP2) = ("a0","a1","a2","a3","t0","t1","t2");
> +
> +$code .= <<___;
> +.p2align 3
> +.globl gcm_init_rv64i_zbc__zbb
> +.type gcm_init_rv64i_zbc__zbb,\@function
> +gcm_init_rv64i_zbc__zbb:
> +    ld      $VAL0,0($H)
> +    ld      $VAL1,8($H)
> +    @{[brev8_rv64i $VAL0, $TMP0, $TMP1, $TMP2]}
> +    @{[brev8_rv64i $VAL1, $TMP0, $TMP1, $TMP2]}
> +    @{[rev8 $VAL0, $VAL0]}
> +    @{[rev8 $VAL1, $VAL1]}
> +    sd      $VAL0,0($Htable)
> +    sd      $VAL1,8($Htable)
> +    ret
> +.size gcm_init_rv64i_zbc__zbb,.-gcm_init_rv64i_zbc__zbb
> +___
> +}
> +
> +{
> +my ($Htable,$H,$TMP0,$TMP1) = ("a0","a1","t0","t1");
> +
> +$code .= <<___;
> +.p2align 3
> +.globl gcm_init_rv64i_zbc__zbkb
> +.type gcm_init_rv64i_zbc__zbkb,\@function
> +gcm_init_rv64i_zbc__zbkb:
> +    ld      $TMP0,0($H)
> +    ld      $TMP1,8($H)
> +    @{[brev8 $TMP0, $TMP0]}
> +    @{[brev8 $TMP1, $TMP1]}
> +    @{[rev8 $TMP0, $TMP0]}
> +    @{[rev8 $TMP1, $TMP1]}
> +    sd      $TMP0,0($Htable)
> +    sd      $TMP1,8($Htable)
> +    ret
> +.size gcm_init_rv64i_zbc__zbkb,.-gcm_init_rv64i_zbc__zbkb
> +___
> +}
> +
> +################################################################################
> +# void gcm_gmult_rv64i_zbc(u64 Xi[2], const u128 Htable[16]);
> +# void gcm_gmult_rv64i_zbc__zbkb(u64 Xi[2], const u128 Htable[16]);
> +#
> +# input:  Xi: current hash value
> +#         Htable: copy of H
> +# output: Xi: next hash value Xi
> +#
> +# Compute GMULT (Xi*H mod f) using the Zbc (clmul) and Zbb (basic bit manip)
> +# extensions. Using the no-Karatsuba approach and clmul for the final reduction.
> +# This results in an implementation with minimized number of instructions.
> +# HW with clmul latencies higher than 2 cycles might observe a performance
> +# improvement with Karatsuba. HW with clmul latencies higher than 6 cycles
> +# might observe a performance improvement with additionally converting the
> +# reduction to shift&xor. For a full discussion of this estimates see
> +# https://github.com/riscv/riscv-crypto/blob/master/doc/supp/gcm-mode-cmul.adoc
> +{
> +my ($Xi,$Htable,$x0,$x1,$y0,$y1) = ("a0","a1","a4","a5","a6","a7");
> +my ($z0,$z1,$z2,$z3,$t0,$t1,$polymod) = ("t0","t1","t2","t3","t4","t5","t6");
> +
> +$code .= <<___;
> +.p2align 3
> +.globl gcm_gmult_rv64i_zbc
> +.type gcm_gmult_rv64i_zbc,\@function
> +gcm_gmult_rv64i_zbc:
> +    # Load Xi and bit-reverse it
> +    ld        $x0, 0($Xi)
> +    ld        $x1, 8($Xi)
> +    @{[brev8_rv64i $x0, $z0, $z1, $z2]}
> +    @{[brev8_rv64i $x1, $z0, $z1, $z2]}
> +
> +    # Load the key (already bit-reversed)
> +    ld        $y0, 0($Htable)
> +    ld        $y1, 8($Htable)
> +
> +    # Load the reduction constant
> +    la        $polymod, Lpolymod
> +    lbu       $polymod, 0($polymod)
> +
> +    # Multiplication (without Karatsuba)
> +    @{[clmulh $z3, $x1, $y1]}
> +    @{[clmul  $z2, $x1, $y1]}
> +    @{[clmulh $t1, $x0, $y1]}
> +    @{[clmul  $z1, $x0, $y1]}
> +    xor       $z2, $z2, $t1
> +    @{[clmulh $t1, $x1, $y0]}
> +    @{[clmul  $t0, $x1, $y0]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $x0, $y0]}
> +    @{[clmul  $z0, $x0, $y0]}
> +    xor       $z1, $z1, $t1
> +
> +    # Reduction with clmul
> +    @{[clmulh $t1, $z3, $polymod]}
> +    @{[clmul  $t0, $z3, $polymod]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $z2, $polymod]}
> +    @{[clmul  $t0, $z2, $polymod]}
> +    xor       $x1, $z1, $t1
> +    xor       $x0, $z0, $t0
> +
> +    # Bit-reverse Xi back and store it
> +    @{[brev8_rv64i $x0, $z0, $z1, $z2]}
> +    @{[brev8_rv64i $x1, $z0, $z1, $z2]}
> +    sd        $x0, 0($Xi)
> +    sd        $x1, 8($Xi)
> +    ret
> +.size gcm_gmult_rv64i_zbc,.-gcm_gmult_rv64i_zbc
> +___
> +}
> +
> +{
> +my ($Xi,$Htable,$x0,$x1,$y0,$y1) = ("a0","a1","a4","a5","a6","a7");
> +my ($z0,$z1,$z2,$z3,$t0,$t1,$polymod) = ("t0","t1","t2","t3","t4","t5","t6");
> +
> +$code .= <<___;
> +.p2align 3
> +.globl gcm_gmult_rv64i_zbc__zbkb
> +.type gcm_gmult_rv64i_zbc__zbkb,\@function
> +gcm_gmult_rv64i_zbc__zbkb:
> +    # Load Xi and bit-reverse it
> +    ld        $x0, 0($Xi)
> +    ld        $x1, 8($Xi)
> +    @{[brev8  $x0, $x0]}
> +    @{[brev8  $x1, $x1]}
> +
> +    # Load the key (already bit-reversed)
> +    ld        $y0, 0($Htable)
> +    ld        $y1, 8($Htable)
> +
> +    # Load the reduction constant
> +    la        $polymod, Lpolymod
> +    lbu       $polymod, 0($polymod)
> +
> +    # Multiplication (without Karatsuba)
> +    @{[clmulh $z3, $x1, $y1]}
> +    @{[clmul  $z2, $x1, $y1]}
> +    @{[clmulh $t1, $x0, $y1]}
> +    @{[clmul  $z1, $x0, $y1]}
> +    xor       $z2, $z2, $t1
> +    @{[clmulh $t1, $x1, $y0]}
> +    @{[clmul  $t0, $x1, $y0]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $x0, $y0]}
> +    @{[clmul  $z0, $x0, $y0]}
> +    xor       $z1, $z1, $t1
> +
> +    # Reduction with clmul
> +    @{[clmulh $t1, $z3, $polymod]}
> +    @{[clmul  $t0, $z3, $polymod]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $z2, $polymod]}
> +    @{[clmul  $t0, $z2, $polymod]}
> +    xor       $x1, $z1, $t1
> +    xor       $x0, $z0, $t0
> +
> +    # Bit-reverse Xi back and store it
> +    @{[brev8  $x0, $x0]}
> +    @{[brev8  $x1, $x1]}
> +    sd        $x0, 0($Xi)
> +    sd        $x1, 8($Xi)
> +    ret
> +.size gcm_gmult_rv64i_zbc__zbkb,.-gcm_gmult_rv64i_zbc__zbkb
> +___
> +}
> +
> +################################################################################
> +# void gcm_ghash_rv64i_zbc(u64 Xi[2], const u128 Htable[16],
> +#                          const u8 *inp, size_t len);
> +# void gcm_ghash_rv64i_zbc__zbkb(u64 Xi[2], const u128 Htable[16],
> +#                                const u8 *inp, size_t len);
> +#
> +# input:  Xi: current hash value
> +#         Htable: copy of H
> +#         inp: pointer to input data
> +#         len: length of input data in bytes (mutiple of block size)
> +# output: Xi: Xi+1 (next hash value Xi)
> +{
> +my ($Xi,$Htable,$inp,$len,$x0,$x1,$y0,$y1) = ("a0","a1","a2","a3","a4","a5","a6","a7");
> +my ($z0,$z1,$z2,$z3,$t0,$t1,$polymod) = ("t0","t1","t2","t3","t4","t5","t6");
> +
> +$code .= <<___;
> +.p2align 3
> +.globl gcm_ghash_rv64i_zbc
> +.type gcm_ghash_rv64i_zbc,\@function
> +gcm_ghash_rv64i_zbc:
> +    # Load Xi and bit-reverse it
> +    ld        $x0, 0($Xi)
> +    ld        $x1, 8($Xi)
> +    @{[brev8_rv64i $x0, $z0, $z1, $z2]}
> +    @{[brev8_rv64i $x1, $z0, $z1, $z2]}
> +
> +    # Load the key (already bit-reversed)
> +    ld        $y0, 0($Htable)
> +    ld        $y1, 8($Htable)
> +
> +    # Load the reduction constant
> +    la        $polymod, Lpolymod
> +    lbu       $polymod, 0($polymod)
> +
> +Lstep:
> +    # Load the input data, bit-reverse them, and XOR them with Xi
> +    ld        $t0, 0($inp)
> +    ld        $t1, 8($inp)
> +    add       $inp, $inp, 16
> +    add       $len, $len, -16
> +    @{[brev8_rv64i $t0, $z0, $z1, $z2]}
> +    @{[brev8_rv64i $t1, $z0, $z1, $z2]}
> +    xor       $x0, $x0, $t0
> +    xor       $x1, $x1, $t1
> +
> +    # Multiplication (without Karatsuba)
> +    @{[clmulh $z3, $x1, $y1]}
> +    @{[clmul  $z2, $x1, $y1]}
> +    @{[clmulh $t1, $x0, $y1]}
> +    @{[clmul  $z1, $x0, $y1]}
> +    xor       $z2, $z2, $t1
> +    @{[clmulh $t1, $x1, $y0]}
> +    @{[clmul  $t0, $x1, $y0]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $x0, $y0]}
> +    @{[clmul  $z0, $x0, $y0]}
> +    xor       $z1, $z1, $t1
> +
> +    # Reduction with clmul
> +    @{[clmulh $t1, $z3, $polymod]}
> +    @{[clmul  $t0, $z3, $polymod]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $z2, $polymod]}
> +    @{[clmul  $t0, $z2, $polymod]}
> +    xor       $x1, $z1, $t1
> +    xor       $x0, $z0, $t0
> +
> +    # Iterate over all blocks
> +    bnez      $len, Lstep
> +
> +    # Bit-reverse final Xi back and store it
> +    @{[brev8_rv64i $x0, $z0, $z1, $z2]}
> +    @{[brev8_rv64i $x1, $z0, $z1, $z2]}
> +    sd        $x0, 0($Xi)
> +    sd        $x1, 8($Xi)
> +    ret
> +.size gcm_ghash_rv64i_zbc,.-gcm_ghash_rv64i_zbc
> +___
> +}
> +
> +{
> +my ($Xi,$Htable,$inp,$len,$x0,$x1,$y0,$y1) = ("a0","a1","a2","a3","a4","a5","a6","a7");
> +my ($z0,$z1,$z2,$z3,$t0,$t1,$polymod) = ("t0","t1","t2","t3","t4","t5","t6");
> +
> +$code .= <<___;
> +.p2align 3
> +.globl gcm_ghash_rv64i_zbc__zbkb
> +.type gcm_ghash_rv64i_zbc__zbkb,\@function
> +gcm_ghash_rv64i_zbc__zbkb:
> +    # Load Xi and bit-reverse it
> +    ld        $x0, 0($Xi)
> +    ld        $x1, 8($Xi)
> +    @{[brev8  $x0, $x0]}
> +    @{[brev8  $x1, $x1]}
> +
> +    # Load the key (already bit-reversed)
> +    ld        $y0, 0($Htable)
> +    ld        $y1, 8($Htable)
> +
> +    # Load the reduction constant
> +    la        $polymod, Lpolymod
> +    lbu       $polymod, 0($polymod)
> +
> +Lstep_zkbk:
> +    # Load the input data, bit-reverse them, and XOR them with Xi
> +    ld        $t0, 0($inp)
> +    ld        $t1, 8($inp)
> +    add       $inp, $inp, 16
> +    add       $len, $len, -16
> +    @{[brev8  $t0, $t0]}
> +    @{[brev8  $t1, $t1]}
> +    xor       $x0, $x0, $t0
> +    xor       $x1, $x1, $t1
> +
> +    # Multiplication (without Karatsuba)
> +    @{[clmulh $z3, $x1, $y1]}
> +    @{[clmul  $z2, $x1, $y1]}
> +    @{[clmulh $t1, $x0, $y1]}
> +    @{[clmul  $z1, $x0, $y1]}
> +    xor       $z2, $z2, $t1
> +    @{[clmulh $t1, $x1, $y0]}
> +    @{[clmul  $t0, $x1, $y0]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $x0, $y0]}
> +    @{[clmul  $z0, $x0, $y0]}
> +    xor       $z1, $z1, $t1
> +
> +    # Reduction with clmul
> +    @{[clmulh $t1, $z3, $polymod]}
> +    @{[clmul  $t0, $z3, $polymod]}
> +    xor       $z2, $z2, $t1
> +    xor       $z1, $z1, $t0
> +    @{[clmulh $t1, $z2, $polymod]}
> +    @{[clmul  $t0, $z2, $polymod]}
> +    xor       $x1, $z1, $t1
> +    xor       $x0, $z0, $t0
> +
> +    # Iterate over all blocks
> +    bnez      $len, Lstep_zkbk
> +
> +    # Bit-reverse final Xi back and store it
> +    @{[brev8  $x0, $x0]}
> +    @{[brev8  $x1, $x1]}
> +    sd $x0,  0($Xi)
> +    sd $x1,  8($Xi)
> +    ret
> +.size gcm_ghash_rv64i_zbc__zbkb,.-gcm_ghash_rv64i_zbc__zbkb
> +___
> +}
> +
> +$code .= <<___;
> +.p2align 3
> +Lbrev8_const:
> +    .dword  0xAAAAAAAAAAAAAAAA
> +    .dword  0xCCCCCCCCCCCCCCCC
> +    .dword  0xF0F0F0F0F0F0F0F0
> +.size Lbrev8_const,.-Lbrev8_const
> +
> +Lpolymod:
> +    .byte 0x87
> +.size Lpolymod,.-Lpolymod
> +___
> +
> +print $code;
> +
> +close STDOUT or die "error closing STDOUT: $!";
> diff --git a/arch/riscv/crypto/riscv.pm b/arch/riscv/crypto/riscv.pm
> new file mode 100644
> index 000000000000..b0c786a13ca0
> --- /dev/null
> +++ b/arch/riscv/crypto/riscv.pm
> @@ -0,0 +1,231 @@
> +#! /usr/bin/env perl
> +# Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
> +#
> +# Licensed under the Apache License 2.0 (the "License").  You may not use
> +# this file except in compliance with the License.  You can obtain a copy
> +# in the file LICENSE in the source distribution or at
> +# https://www.openssl.org/source/license.html
> +
> +use strict;
> +use warnings;
> +
> +# Set $have_stacktrace to 1 if we have Devel::StackTrace
> +my $have_stacktrace = 0;
> +if (eval {require Devel::StackTrace;1;}) {
> +    $have_stacktrace = 1;
> +}
> +
> +my @regs = map("x$_",(0..31));
> +# Mapping from the RISC-V psABI ABI mnemonic names to the register number.
> +my @regaliases = ('zero','ra','sp','gp','tp','t0','t1','t2','s0','s1',
> +    map("a$_",(0..7)),
> +    map("s$_",(2..11)),
> +    map("t$_",(3..6))
> +);
> +
> +my %reglookup;
> +@reglookup{@regs} = @regs;
> +@reglookup{@regaliases} = @regs;
> +
> +# Takes a register name, possibly an alias, and converts it to a register index
> +# from 0 to 31
> +sub read_reg {
> +    my $reg = lc shift;
> +    if (!exists($reglookup{$reg})) {
> +        my $trace = "";
> +        if ($have_stacktrace) {
> +            $trace = Devel::StackTrace->new->as_string;
> +        }
> +        die("Unknown register ".$reg."\n".$trace);
> +    }
> +    my $regstr = $reglookup{$reg};
> +    if (!($regstr =~ /^x([0-9]+)$/)) {
> +        my $trace = "";
> +        if ($have_stacktrace) {
> +            $trace = Devel::StackTrace->new->as_string;
> +        }
> +        die("Could not process register ".$reg."\n".$trace);
> +    }
> +    return $1;
> +}
> +
> +# Helper functions
> +
> +sub brev8_rv64i {
> +    # brev8 without `brev8` instruction (only in Zbkb)
> +    # Bit-reverses the first argument and needs two scratch registers
> +    my $val = shift;
> +    my $t0 = shift;
> +    my $t1 = shift;
> +    my $brev8_const = shift;
> +    my $seq = <<___;
> +        la      $brev8_const, Lbrev8_const
> +
> +        ld      $t0, 0($brev8_const)  # 0xAAAAAAAAAAAAAAAA
> +        slli    $t1, $val, 1
> +        and     $t1, $t1, $t0
> +        and     $val, $val, $t0
> +        srli    $val, $val, 1
> +        or      $val, $t1, $val
> +
> +        ld      $t0, 8($brev8_const)  # 0xCCCCCCCCCCCCCCCC
> +        slli    $t1, $val, 2
> +        and     $t1, $t1, $t0
> +        and     $val, $val, $t0
> +        srli    $val, $val, 2
> +        or      $val, $t1, $val
> +
> +        ld      $t0, 16($brev8_const) # 0xF0F0F0F0F0F0F0F0
> +        slli    $t1, $val, 4
> +        and     $t1, $t1, $t0
> +        and     $val, $val, $t0
> +        srli    $val, $val, 4
> +        or      $val, $t1, $val
> +___
> +    return $seq;
> +}
> +
> +sub sd_rev8_rv64i {
> +    # rev8 without `rev8` instruction (only in Zbb or Zbkb)
> +    # Stores the given value byte-reversed and needs one scratch register
> +    my $val = shift;
> +    my $addr = shift;
> +    my $off = shift;
> +    my $tmp = shift;
> +    my $off0 = ($off + 0);
> +    my $off1 = ($off + 1);
> +    my $off2 = ($off + 2);
> +    my $off3 = ($off + 3);
> +    my $off4 = ($off + 4);
> +    my $off5 = ($off + 5);
> +    my $off6 = ($off + 6);
> +    my $off7 = ($off + 7);
> +    my $seq = <<___;
> +        sb      $val, $off7($addr)
> +        srli    $tmp, $val, 8
> +        sb      $tmp, $off6($addr)
> +        srli    $tmp, $val, 16
> +        sb      $tmp, $off5($addr)
> +        srli    $tmp, $val, 24
> +        sb      $tmp, $off4($addr)
> +        srli    $tmp, $val, 32
> +        sb      $tmp, $off3($addr)
> +        srli    $tmp, $val, 40
> +        sb      $tmp, $off2($addr)
> +        srli    $tmp, $val, 48
> +        sb      $tmp, $off1($addr)
> +        srli    $tmp, $val, 56
> +        sb      $tmp, $off0($addr)
> +___
> +    return $seq;
> +}
> +
> +# Scalar crypto instructions
> +
> +sub aes64ds {
> +    # Encoding for aes64ds rd, rs1, rs2 instruction on RV64
> +    #                XXXXXXX_ rs2 _ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b0011101_00000_00000_000_00000_0110011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rs2 = read_reg shift;
> +    return ".word ".($template | ($rs2 << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub aes64dsm {
> +    # Encoding for aes64dsm rd, rs1, rs2 instruction on RV64
> +    #                XXXXXXX_ rs2 _ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b0011111_00000_00000_000_00000_0110011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rs2 = read_reg shift;
> +    return ".word ".($template | ($rs2 << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub aes64es {
> +    # Encoding for aes64es rd, rs1, rs2 instruction on RV64
> +    #                XXXXXXX_ rs2 _ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b0011001_00000_00000_000_00000_0110011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rs2 = read_reg shift;
> +    return ".word ".($template | ($rs2 << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub aes64esm {
> +    # Encoding for aes64esm rd, rs1, rs2 instruction on RV64
> +    #                XXXXXXX_ rs2 _ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b0011011_00000_00000_000_00000_0110011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rs2 = read_reg shift;
> +    return ".word ".($template | ($rs2 << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub aes64im {
> +    # Encoding for aes64im rd, rs1 instruction on RV64
> +    #                XXXXXXXXXXXX_ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b001100000000_00000_001_00000_0010011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    return ".word ".($template | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub aes64ks1i {
> +    # Encoding for aes64ks1i rd, rs1, rnum instruction on RV64
> +    #                XXXXXXXX_rnum_ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b00110001_0000_00000_001_00000_0010011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rnum = shift;
> +    return ".word ".($template | ($rnum << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub aes64ks2 {
> +    # Encoding for aes64ks2 rd, rs1, rs2 instruction on RV64
> +    #                XXXXXXX_ rs2 _ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b0111111_00000_00000_000_00000_0110011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rs2 = read_reg shift;
> +    return ".word ".($template | ($rs2 << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub brev8 {
> +    # brev8 rd, rs
> +    my $template = 0b011010000111_00000_101_00000_0010011;
> +    my $rd = read_reg shift;
> +    my $rs = read_reg shift;
> +    return ".word ".($template | ($rs << 15) | ($rd << 7));
> +}
> +
> +sub clmul {
> +    # Encoding for clmul rd, rs1, rs2 instruction on RV64
> +    #                XXXXXXX_ rs2 _ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b0000101_00000_00000_001_00000_0110011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rs2 = read_reg shift;
> +    return ".word ".($template | ($rs2 << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub clmulh {
> +    # Encoding for clmulh rd, rs1, rs2 instruction on RV64
> +    #                XXXXXXX_ rs2 _ rs1 _XXX_ rd  _XXXXXXX
> +    my $template = 0b0000101_00000_00000_011_00000_0110011;
> +    my $rd = read_reg shift;
> +    my $rs1 = read_reg shift;
> +    my $rs2 = read_reg shift;
> +    return ".word ".($template | ($rs2 << 20) | ($rs1 << 15) | ($rd << 7));
> +}
> +
> +sub rev8 {
> +    # Encoding for rev8 rd, rs instruction on RV64
> +    #               XXXXXXXXXXXXX_ rs  _XXX_ rd  _XXXXXXX
> +    my $template = 0b011010111000_00000_101_00000_0010011;
> +    my $rd = read_reg shift;
> +    my $rs = read_reg shift;
> +    return ".word ".($template | ($rs << 15) | ($rd << 7));
> +}
> +
> +1;
> --
> 2.39.0
>

Thanks,
Huck
Heiko Stübner May 11, 2023, 10:30 a.m. UTC | #2 
Hi Nathan,

Am Dienstag, 11. April 2023, 17:00:00 CEST schrieb Nathan Huckleberry:
> On Wed, Mar 29, 2023 at 7:08 AM Heiko Stuebner <heiko@sntech.de> wrote:
> > +struct riscv64_ghash_ctx {
> > +       void (*ghash_func)(u64 Xi[2], const u128 Htable[16],
> > +                          const u8 *inp, size_t len);
> > +
> > +       /* key used by vector asm */
> > +       u128 htable[16];
> 
> This field looks too big. The assembly only loads the first 128-byte
> value from this table.

OpenSSL defines the Htable field handed to the init- and the other
functions as this "u128 Htable[16]"    [0] . As I really like the concept
of keeping in sync with openSSL, I guess I'd rather not change that.

[0] https://github.com/openssl/openssl/blob/master/crypto/modes/gcm128.c#L88


> Is this copied from another implementation? There's an optimization
> where you precompute the first N powers of H so that you can perform 1
> finite field reduction for every N multiplications, but it doesn't
> look like that's being used here.

The whole crypto-specific code comes from openSSL itself, so for now I
guess I'd like to try keeping things the same.


> > +#define RISCV64_ZBC_SETKEY(VARIANT, GHASH)                             \
> > +void gcm_init_rv64i_ ## VARIANT(u128 Htable[16], const u64 Xi[2]);     \
> > +static int riscv64_zbc_ghash_setkey_ ## VARIANT(struct crypto_shash *tfm,      \
> > +                                          const u8 *key,               \
> > +                                          unsigned int keylen)         \
> > +{                                                                      \
> > +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm)); \
> > +       const u64 k[2] = { cpu_to_be64(((const u64 *)key)[0]),          \
> > +                          cpu_to_be64(((const u64 *)key)[1]) };        \
> > +                                                                       \
> > +       if (keylen != GHASH_BLOCK_SIZE)                                 \
> > +               return -EINVAL;                                         \
> > +                                                                       \
> > +       memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);                       \
> > +       gcm_init_rv64i_ ## VARIANT(ctx->htable, k);                     \
> > +                                                                       \
> > +       ctx->ghash_func = gcm_ghash_rv64i_ ## GHASH;                    \
> > +                                                                       \
> > +       return 0;                                                       \
> > +}
> 
> I'd prefer three identical functions over a macro here. Code searching
> tools and compiler warnings are significantly worse with macros.

done :-)


> > +
> > +static int riscv64_zbc_ghash_update(struct shash_desc *desc,
> > +                          const u8 *src, unsigned int srclen)
> > +{
> > +       unsigned int len;
> > +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
> > +       struct riscv64_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
> > +
> > +       if (dctx->bytes) {
> > +               if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
> > +                       memcpy(dctx->buffer + dctx->bytes, src,
> > +                               srclen);
> > +                       dctx->bytes += srclen;
> > +                       return 0;
> > +               }
> > +               memcpy(dctx->buffer + dctx->bytes, src,
> > +                       GHASH_DIGEST_SIZE - dctx->bytes);
> > +
> > +               ctx->ghash_func(dctx->shash, ctx->htable,
> > +                               dctx->buffer, GHASH_DIGEST_SIZE);
> > +
> > +               src += GHASH_DIGEST_SIZE - dctx->bytes;
> > +               srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
> > +               dctx->bytes = 0;
> > +       }
> > +       len = srclen & ~(GHASH_DIGEST_SIZE - 1);
> > +
> > +       if (len) {
> > +               gcm_ghash_rv64i_zbc(dctx->shash, ctx->htable,
> > +                               src, len);
> > +               src += len;
> > +               srclen -= len;
> > +       }
> > +
> > +       if (srclen) {
> > +               memcpy(dctx->buffer, src, srclen);
> > +               dctx->bytes = srclen;
> > +       }
> > +       return 0;
> > +}
> > +
> > +static int riscv64_zbc_ghash_final(struct shash_desc *desc, u8 *out)
> > +{
> > +       int i;
> > +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
> > +       struct riscv64_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
> > +
> > +       if (dctx->bytes) {
> > +               for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
> > +                       dctx->buffer[i] = 0;
> > +               ctx->ghash_func(dctx->shash, ctx->htable,
> > +                               dctx->buffer, GHASH_DIGEST_SIZE);
> 
> Can we do this without an indirect call?

hmm, the indirect call is in both riscv64_zbc_ghash_update() and
riscv64_zbc_ghash_final() . And I found a missing one at the bottom
of riscv64_zbc_ghash_update(), where gcm_ghash_rv64i_zbc() is
called right now.

Getting rid of the indirect call would mean duplicating both of these
functions for all instances. Especially with the slightly higher
complexity of the update this somehow seems not the best way to go.


Thanks for your pointers
Heiko
Nathan Huckleberry May 11, 2023, 7:02 p.m. UTC | #3 
On Thu, May 11, 2023 at 3:30 AM Heiko Stübner <heiko@sntech.de> wrote:
>
> Hi Nathan,
>
> Am Dienstag, 11. April 2023, 17:00:00 CEST schrieb Nathan Huckleberry:
> > On Wed, Mar 29, 2023 at 7:08 AM Heiko Stuebner <heiko@sntech.de> wrote:
> > > +struct riscv64_ghash_ctx {
> > > +       void (*ghash_func)(u64 Xi[2], const u128 Htable[16],
> > > +                          const u8 *inp, size_t len);
> > > +
> > > +       /* key used by vector asm */
> > > +       u128 htable[16];
> >
> > This field looks too big. The assembly only loads the first 128-byte
> > value from this table.
>
> OpenSSL defines the Htable field handed to the init- and the other
> functions as this "u128 Htable[16]"    [0] . As I really like the concept
> of keeping in sync with openSSL, I guess I'd rather not change that.
>
> [0] https://github.com/openssl/openssl/blob/master/crypto/modes/gcm128.c#L88
>
>
> > Is this copied from another implementation? There's an optimization
> > where you precompute the first N powers of H so that you can perform 1
> > finite field reduction for every N multiplications, but it doesn't
> > look like that's being used here.
>
> The whole crypto-specific code comes from openSSL itself, so for now I
> guess I'd like to try keeping things the same.
>
>
> > > +#define RISCV64_ZBC_SETKEY(VARIANT, GHASH)                             \
> > > +void gcm_init_rv64i_ ## VARIANT(u128 Htable[16], const u64 Xi[2]);     \
> > > +static int riscv64_zbc_ghash_setkey_ ## VARIANT(struct crypto_shash *tfm,      \
> > > +                                          const u8 *key,               \
> > > +                                          unsigned int keylen)         \
> > > +{                                                                      \
> > > +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm)); \
> > > +       const u64 k[2] = { cpu_to_be64(((const u64 *)key)[0]),          \
> > > +                          cpu_to_be64(((const u64 *)key)[1]) };        \
> > > +                                                                       \
> > > +       if (keylen != GHASH_BLOCK_SIZE)                                 \
> > > +               return -EINVAL;                                         \
> > > +                                                                       \
> > > +       memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);                       \
> > > +       gcm_init_rv64i_ ## VARIANT(ctx->htable, k);                     \
> > > +                                                                       \
> > > +       ctx->ghash_func = gcm_ghash_rv64i_ ## GHASH;                    \
> > > +                                                                       \
> > > +       return 0;                                                       \
> > > +}
> >
> > I'd prefer three identical functions over a macro here. Code searching
> > tools and compiler warnings are significantly worse with macros.
>
> done :-)
>
>
> > > +
> > > +static int riscv64_zbc_ghash_update(struct shash_desc *desc,
> > > +                          const u8 *src, unsigned int srclen)
> > > +{
> > > +       unsigned int len;
> > > +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
> > > +       struct riscv64_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
> > > +
> > > +       if (dctx->bytes) {
> > > +               if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
> > > +                       memcpy(dctx->buffer + dctx->bytes, src,
> > > +                               srclen);
> > > +                       dctx->bytes += srclen;
> > > +                       return 0;
> > > +               }
> > > +               memcpy(dctx->buffer + dctx->bytes, src,
> > > +                       GHASH_DIGEST_SIZE - dctx->bytes);
> > > +
> > > +               ctx->ghash_func(dctx->shash, ctx->htable,
> > > +                               dctx->buffer, GHASH_DIGEST_SIZE);
> > > +
> > > +               src += GHASH_DIGEST_SIZE - dctx->bytes;
> > > +               srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
> > > +               dctx->bytes = 0;
> > > +       }
> > > +       len = srclen & ~(GHASH_DIGEST_SIZE - 1);
> > > +
> > > +       if (len) {
> > > +               gcm_ghash_rv64i_zbc(dctx->shash, ctx->htable,
> > > +                               src, len);
> > > +               src += len;
> > > +               srclen -= len;
> > > +       }
> > > +
> > > +       if (srclen) {
> > > +               memcpy(dctx->buffer, src, srclen);
> > > +               dctx->bytes = srclen;
> > > +       }
> > > +       return 0;
> > > +}
> > > +
> > > +static int riscv64_zbc_ghash_final(struct shash_desc *desc, u8 *out)
> > > +{
> > > +       int i;
> > > +       struct riscv64_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
> > > +       struct riscv64_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
> > > +
> > > +       if (dctx->bytes) {
> > > +               for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
> > > +                       dctx->buffer[i] = 0;
> > > +               ctx->ghash_func(dctx->shash, ctx->htable,
> > > +                               dctx->buffer, GHASH_DIGEST_SIZE);
> >
> > Can we do this without an indirect call?
>
> hmm, the indirect call is in both riscv64_zbc_ghash_update() and
> riscv64_zbc_ghash_final() . And I found a missing one at the bottom
> of riscv64_zbc_ghash_update(), where gcm_ghash_rv64i_zbc() is
> called right now.
>
> Getting rid of the indirect call would mean duplicating both of these
> functions for all instances. Especially with the slightly higher
> complexity of the update this somehow seems not the best way to go.

Indirect calls are quite expensive. They are an issue for things like
disk/filesystem encryption because it introduces a ton of latency per
block.

I think this is a candidate for static calls. It looks like static
call support hasn't been accepted for riscv yet. Maybe just add a TODO
for now?

See:
https://lwn.net/Articles/771209/
https://lore.kernel.org/all/tencent_A8A256967B654625AEE1DB222514B0613B07@qq.com/

>
>
> Thanks for your pointers
> Heiko
>
>

Thanks,
Huck