crypto: riscv - add vector crypto accelerated AES-{ECB,CBC,CTR,XTS}

Add implementations of AES-ECB, AES-CBC, AES-CTR, and AES-XTS, as well
as bare (single-block) AES, using the RISC-V vector crypto extensions.
The assembly code is derived from OpenSSL code (openssl/openssl#21923)
that was dual-licensed so that it could be reused in the kernel.
Nevertheless, the assembly has been significantly reworked for
integration with the kernel, for example by using regular .S files
instead of the so-called perlasm, using the assembler instead of bare
'.inst', greatly reducing code duplication, supporting AES-192, and
making the code use the same AES key structure as the C code.

Co-developed-by: Phoebe Chen <phoebe.chen@sifive.com>
Signed-off-by: Phoebe Chen <phoebe.chen@sifive.com>
Signed-off-by: Jerry Shih <jerry.shih@sifive.com>
Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240122002024.27477-5-ebiggers@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

arch/riscv/crypto/Kconfig

@@ -2,4 +2,20 @@
 
 menu "Accelerated Cryptographic Algorithms for CPU (riscv)"
 
+config CRYPTO_AES_RISCV64
+	tristate "Ciphers: AES, modes: ECB, CBC, CTR, XTS"
+	depends on 64BIT && RISCV_ISA_V && TOOLCHAIN_HAS_VECTOR_CRYPTO
+	select CRYPTO_ALGAPI
+	select CRYPTO_LIB_AES
+	select CRYPTO_SKCIPHER
+	help
+	  Block cipher: AES cipher algorithms
+	  Length-preserving ciphers: AES with ECB, CBC, CTR, XTS
+
+	  Architecture: riscv64 using:
+	  - Zvkned vector crypto extension
+	  - Zvbb vector extension (XTS)
+	  - Zvkb vector crypto extension (CTR)
+	  - Zvkg vector crypto extension (XTS)
+
 endmenu

arch/riscv/crypto/Makefile

@@ -1 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_CRYPTO_AES_RISCV64) += aes-riscv64.o
+aes-riscv64-y := aes-riscv64-glue.o aes-riscv64-zvkned.o \
+		 aes-riscv64-zvkned-zvbb-zvkg.o aes-riscv64-zvkned-zvkb.o

arch/riscv/crypto/aes-macros.S

@@ -0,0 +1,156 @@
+/* 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 (c) 2023, Jerry Shih <jerry.shih@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.
+
+// This file contains macros that are shared by the other aes-*.S files.  The
+// generated code of these macros depends on the following RISC-V extensions:
+// - RV64I
+// - RISC-V Vector ('V') with VLEN >= 128
+// - RISC-V Vector AES block cipher extension ('Zvkned')
+
+// Loads the AES round keys from \keyp into vector registers and jumps to code
+// specific to the length of the key.  Specifically:
+//   - If AES-128, loads round keys into v1-v11 and jumps to \label128.
+//   - If AES-192, loads round keys into v1-v13 and jumps to \label192.
+//   - If AES-256, loads round keys into v1-v15 and continues onwards.
+//
+// Also sets vl=4 and vtype=e32,m1,ta,ma.  Clobbers t0 and t1.
+.macro	aes_begin	keyp, label128, label192
+	lwu		t0, 480(\keyp)	// t0 = key length in bytes
+	li		t1, 24		// t1 = key length for AES-192
+	vsetivli	zero, 4, e32, m1, ta, ma
+	vle32.v		v1, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v2, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v3, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v4, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v5, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v6, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v7, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v8, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v9, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v10, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v11, (\keyp)
+	blt		t0, t1, \label128	// If AES-128, goto label128.
+	addi		\keyp, \keyp, 16
+	vle32.v		v12, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v13, (\keyp)
+	beq		t0, t1, \label192	// If AES-192, goto label192.
+	// Else, it's AES-256.
+	addi		\keyp, \keyp, 16
+	vle32.v		v14, (\keyp)
+	addi		\keyp, \keyp, 16
+	vle32.v		v15, (\keyp)
+.endm
+
+// Encrypts \data using zvkned instructions, using the round keys loaded into
+// v1-v11 (for AES-128), v1-v13 (for AES-192), or v1-v15 (for AES-256).  \keylen
+// is the AES key length in bits.  vl and vtype must already be set
+// appropriately.  Note that if vl > 4, multiple blocks are encrypted.
+.macro	aes_encrypt	data, keylen
+	vaesz.vs	\data, v1
+	vaesem.vs	\data, v2
+	vaesem.vs	\data, v3
+	vaesem.vs	\data, v4
+	vaesem.vs	\data, v5
+	vaesem.vs	\data, v6
+	vaesem.vs	\data, v7
+	vaesem.vs	\data, v8
+	vaesem.vs	\data, v9
+	vaesem.vs	\data, v10
+.if \keylen == 128
+	vaesef.vs	\data, v11
+.elseif \keylen == 192
+	vaesem.vs	\data, v11
+	vaesem.vs	\data, v12
+	vaesef.vs	\data, v13
+.else
+	vaesem.vs	\data, v11
+	vaesem.vs	\data, v12
+	vaesem.vs	\data, v13
+	vaesem.vs	\data, v14
+	vaesef.vs	\data, v15
+.endif
+.endm
+
+// Same as aes_encrypt, but decrypts instead of encrypts.
+.macro	aes_decrypt	data, keylen
+.if \keylen == 128
+	vaesz.vs	\data, v11
+.elseif \keylen == 192
+	vaesz.vs	\data, v13
+	vaesdm.vs	\data, v12
+	vaesdm.vs	\data, v11
+.else
+	vaesz.vs	\data, v15
+	vaesdm.vs	\data, v14
+	vaesdm.vs	\data, v13
+	vaesdm.vs	\data, v12
+	vaesdm.vs	\data, v11
+.endif
+	vaesdm.vs	\data, v10
+	vaesdm.vs	\data, v9
+	vaesdm.vs	\data, v8
+	vaesdm.vs	\data, v7
+	vaesdm.vs	\data, v6
+	vaesdm.vs	\data, v5
+	vaesdm.vs	\data, v4
+	vaesdm.vs	\data, v3
+	vaesdm.vs	\data, v2
+	vaesdf.vs	\data, v1
+.endm
+
+// Expands to aes_encrypt or aes_decrypt according to \enc, which is 1 or 0.
+.macro	aes_crypt	data, enc, keylen
+.if \enc
+	aes_encrypt	\data, \keylen
+.else
+	aes_decrypt	\data, \keylen
+.endif
+.endm