[RFC PATCH 6/6] riscv: Add BLAKE2s V implementation

Björn Töpel bjorn at kernel.org
Tue Sep 12 04:57:28 PDT 2023


From: Björn Töpel <bjorn at rivosinc.com>

BLAKE2s is used in various places, most notably in Wireguard, and as
of v5.17 in drivers/char/random.

Add a BLAKE2s implementation using the V-extension. This is a
translation of the x86-64 AVX512 variant
(arch/x86/crypto/blake2s-core.S) to the RISC-V V-extension.

The AVX512 variant requires registers >= 256b (ymm*), and hence this
implementation requires a VLEN of >=256.

The implementation passes the kernel BLAKE2s selftest, and has been
tested on spike and qemu.

Instruction-wise, the V-variant uses 60% less instructions than the
generic, C-based, implementation.

Signed-off-by: Björn Töpel <bjorn at rivosinc.com>
---
 arch/riscv/Kbuild                |   2 +-
 arch/riscv/crypto/Kconfig        |  16 +++
 arch/riscv/crypto/Makefile       |   6 ++
 arch/riscv/crypto/blake2s-glue.c |  39 ++++++++
 arch/riscv/crypto/blake2s-v.S    | 164 +++++++++++++++++++++++++++++++
 crypto/Kconfig                   |   3 +
 drivers/net/Kconfig              |   1 +
 7 files changed, 230 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/crypto/Kconfig
 create mode 100644 arch/riscv/crypto/Makefile
 create mode 100644 arch/riscv/crypto/blake2s-glue.c
 create mode 100644 arch/riscv/crypto/blake2s-v.S

diff --git a/arch/riscv/Kbuild b/arch/riscv/Kbuild
index d25ad1c19f88..1a5d89a18920 100644
--- a/arch/riscv/Kbuild
+++ b/arch/riscv/Kbuild
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
-obj-y += kernel/ mm/ net/
+obj-y += kernel/ mm/ net/ crypto/
 obj-$(CONFIG_BUILTIN_DTB) += boot/dts/
 obj-y += errata/
 obj-$(CONFIG_KVM) += kvm/
diff --git a/arch/riscv/crypto/Kconfig b/arch/riscv/crypto/Kconfig
new file mode 100644
index 000000000000..e072400eb456
--- /dev/null
+++ b/arch/riscv/crypto/Kconfig
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menu "Accelerated Cryptographic Algorithms for CPU (RISC-V)"
+
+config CRYPTO_BLAKE2S_RISCV
+	bool "Hash functions: BLAKE2s (V)"
+	depends on 64BIT && MMU && RISCV_ISA_V
+	select CRYPTO_LIB_BLAKE2S_GENERIC
+	select CRYPTO_ARCH_HAVE_LIB_BLAKE2S
+	help
+	  BLAKE2s cryptographic hash function (RFC 7693)
+
+	  Architecture: riscv64 using:
+	  - V extension (VLEN >= 256)
+
+endmenu
diff --git a/arch/riscv/crypto/Makefile b/arch/riscv/crypto/Makefile
new file mode 100644
index 000000000000..1768025c13ae
--- /dev/null
+++ b/arch/riscv/crypto/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# RISC-V crypto algorithms
+
+obj-$(CONFIG_CRYPTO_BLAKE2S_RISCV) += libblake2s-riscv.o
+libblake2s-riscv-y := blake2s-v.o blake2s-glue.o
diff --git a/arch/riscv/crypto/blake2s-glue.c b/arch/riscv/crypto/blake2s-glue.c
new file mode 100644
index 000000000000..d3de0e8e5872
--- /dev/null
+++ b/arch/riscv/crypto/blake2s-glue.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2022 Rivos, Inc. All Rights Reserved.
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason at zx2c4.com>. All Rights Reserved.
+ */
+
+#include <crypto/internal/blake2s.h>
+
+#include <linux/types.h>
+#include <linux/minmax.h>
+#include <linux/sizes.h>
+
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <asm/simd.h>
+#include <asm/vector.h>
+
+asmlinkage void blake2s_compress_vector(struct blake2s_state *state, const u8 *block,
+					const size_t nblocks, const u32 inc);
+
+void blake2s_compress(struct blake2s_state *state, const u8 *block, size_t nblocks, const u32 inc)
+{
+	if (!(has_vector() && riscv_v_vsize >= 256 * 32 / 8) || !may_use_simd()) {
+		blake2s_compress_generic(state, block, nblocks, inc);
+		return;
+	}
+
+	do {
+		const size_t blocks = min_t(size_t, nblocks, SZ_4K / BLAKE2S_BLOCK_SIZE);
+
+		kernel_vector_begin();
+		blake2s_compress_vector(state, block, blocks, inc);
+		kernel_vector_end();
+
+		nblocks -= blocks;
+		block += blocks * BLAKE2S_BLOCK_SIZE;
+	} while (nblocks);
+}
+EXPORT_SYMBOL(blake2s_compress);
diff --git a/arch/riscv/crypto/blake2s-v.S b/arch/riscv/crypto/blake2s-v.S
new file mode 100644
index 000000000000..9653b7a19127
--- /dev/null
+++ b/arch/riscv/crypto/blake2s-v.S
@@ -0,0 +1,164 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/*
+ * BLAKE2s RISC-V V implementation
+ *
+ * Copyright (C) 2022 Rivos, Inc. All Rights Reserved.
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason at zx2c4.com>. All Rights Reserved.
+ * Copyright (C) 2017-2019 Samuel Neves <sneves at dei.uc.pt>. All Rights Reserved.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+
+.section .rodata, "a", @progbits
+
+.align 8
+IV:
+.octa 0xA54FF53A3C6EF372BB67AE856A09E667
+.octa 0x5BE0CD191F83D9AB9B05688C510E527F
+
+.align 8
+SIGMA2:
+.long  0,  2,  4,  6,  1,  3,  5,  7, 14,  8, 10, 12, 15,  9, 11, 13
+.long  8,  2, 13, 15, 10,  9, 12,  3,  6,  4,  0, 14,  5, 11,  1,  7
+.long 11, 13,  8,  6,  5, 10, 14,  3,  2,  4, 12, 15,  1,  0,  7,  9
+.long 11, 10,  7,  0,  8, 15,  1, 13,  3,  6,  2, 12,  4, 14,  9,  5
+.long  4, 10,  9, 14, 15,  0, 11,  8,  1,  7,  3, 13,  2,  5,  6, 12
+.long  2, 11,  4, 15, 14,  3, 10,  8, 13,  6,  5,  7,  0, 12,  1,  9
+.long  4,  8, 15,  9, 14, 11, 13,  5,  3,  2,  1, 12,  6, 10,  7,  0
+.long  6, 13,  0, 14, 12,  2,  1, 11, 15,  4,  5,  8,  7,  9,  3, 10
+.long 15,  5,  4, 13, 10,  7,  3, 11, 12,  2,  0,  6,  9,  8,  1, 14
+.long  8,  7, 14, 11, 13, 15,  0, 12, 10,  4,  5,  6,  3,  2,  1,  9
+
+.align 8
+GATHER_DIAG1:
+.long  3, 0, 1, 2
+.align 8
+GATHER_DIAG2:
+.long  2, 3, 0, 1
+.align 8
+GATHER_DIAG3:
+.long  1, 2, 3, 0
+
+.section .text
+
+.macro VROR REG BITS TMPREG
+	vmv.v.v		\TMPREG, \REG
+	vsrl.vi		\REG, \REG, \BITS
+	vsll.vi		\TMPREG, \TMPREG, 32-\BITS
+	vor.vv		\REG, \REG, \TMPREG
+.endm
+
+/*
+ * void blake2s_compress_vector(struct blake2s_state *state,
+ *        const u8 *block, size_t nblocks, const u32 inc)
+ *
+ * blake2s_compress_vector is a translation of the AVX512 variant
+ * (arch/x86/blake2s-core.S) to RISC-V V. The implementation requires
+ * VLEN>=256b.
+ *
+ */
+SYM_FUNC_START(blake2s_compress_vector)
+	vsetivli	t0, 1, e32, m1, ta, ma
+	vmv.v.x		v5, a3
+	vsetivli	t0, 4, e32, m1, ta, ma
+	vle32.v		v0, (a0)
+	addi		t0, a0, 0x10
+	vle32.v		v1, (t0)
+	addi		t0, t0, 0x10
+	vle32.v		v4, (t0)
+	la		t0, IV
+	vle32.v		v14, (t0)
+	la		t0, IV+16
+	vle32.v		v15, (t0)
+	la		t0, GATHER_DIAG1
+	vle32.v		v16, (t0)
+	la		t0, GATHER_DIAG2
+	vle32.v		v18, (t0)
+	la		t0, GATHER_DIAG3
+	vle32.v		v19, (t0)
+.Lblake2s_compress_vector_mainloop:
+	vmv.v.v		v10, v0
+	vmv.v.v		v11, v1
+	vadd.vv		v4, v5, v4
+	vmv.v.v		v2, v14
+	vxor.vv		v3, v15, v4
+	vsetivli	t0, 8, e32, m1, ta, ma
+	vle32.v		v6, (a1)
+	addi		a1, a1, 0x20
+	vle32.v		v7, (a1)
+	addi		a1, a1, 0x20
+	la		t1, SIGMA2
+	li		t2, 0xa
+.Lblake2s_compress_vector_roundloop:
+	vsetivli	t0, 8, e32, m1, ta, ma
+	vle32.v		v12, (t1)
+	addi		t1, t1, 0x20
+	vle32.v		v13, (t1)
+	addi		t1, t1, 0x20
+	vsetivli	t0, 16, e32, m2, ta, ma
+	vrgather.vv	v8, v6, v12
+	vmv.v.v		v6, v8
+	vsetivli	t0, 4, e32, m1, ta, ma
+	vadd.vv		v0, v8, v0
+	vadd.vv		v0, v1, v0
+	vxor.vv		v3, v0, v3
+	VROR		v3 16 v17
+	vadd.vv		v2, v3, v2
+	vxor.vv		v1, v2, v1
+	VROR		v1 12 v17
+	vsetivli	t0, 8, e32, m1, ta, ma
+	vslidedown.vi	v8, v8, 4
+	vsetivli	t0, 4, e32, m1, ta, ma
+	vadd.vv		v0, v8, v0
+	vadd.vv		v0, v1, v0
+	vxor.vv		v3, v0, v3
+	VROR		v3 8 v17
+	vadd.vv		v2, v3, v2
+	vxor.vv		v1, v2, v1
+	VROR		v1, 7, v17
+	vmv.v.v		v17, v0
+	vrgather.vv	v0, v17, v16
+	vmv.v.v		v17, v3
+	vrgather.vv	v3, v17, v18
+	vmv.v.v		v17, v2
+	vrgather.vv	v2, v17, v19
+	vadd.vv		v0, v9, v0
+	vadd.vv		v0, v1, v0
+	vxor.vv		v3, v0, v3
+	VROR		v3 16 v17
+	vadd.vv		v2, v3, v2
+	vxor.vv		v1, v2, v1
+	VROR		v1 12 v17
+	vsetivli	t0, 8, e32, m1, ta, ma
+	vslidedown.vi	v9, v9, 4
+	vsetivli	t0, 4, e32, m1, ta, ma
+	vadd.vv		v0, v9, v0
+	vadd.vv		v0, v1, v0
+	vxor.vv		v3, v0, v3
+	VROR		v3, 8, v17
+	vadd.vv		v2, v3, v2
+	vxor.vv		v1, v2, v1
+	VROR		v1 7 v17
+	vmv.v.v		v17, v0
+	vrgather.vv	v0, v17, v19
+	vmv.v.v		v17, v3
+	vrgather.vv	v3, v17, v18
+	vmv.v.v		v17, v2
+	vrgather.vv	v2, v17, v16
+	addi		t2, t2, -1
+	bne		t2, x0, .Lblake2s_compress_vector_roundloop
+	vxor.vv		v0, v10, v0
+	vxor.vv		v1, v11, v1
+	vxor.vv		v0, v2, v0
+	vxor.vv		v1, v3, v1
+	addi		a2, a2, -1
+	bne		a2, x0, .Lblake2s_compress_vector_mainloop
+	vse32.v		v0, (a0)
+	addi		a0, a0, 0x10
+	vse32.v		v1, (a0)
+	addi		a0, a0, 0x10
+	vse32.v		v4, (a0)
+	ret
+SYM_FUNC_END(blake2s_compress_vector)
+
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 650b1b3620d8..c7b23d2c58e4 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1436,6 +1436,9 @@ endif
 if PPC
 source "arch/powerpc/crypto/Kconfig"
 endif
+if RISCV
+source "arch/riscv/crypto/Kconfig"
+endif
 if S390
 source "arch/s390/crypto/Kconfig"
 endif
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 44eeb5d61ba9..f7fb168a3944 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -94,6 +94,7 @@ config WIREGUARD
 	select CRYPTO_CHACHA_MIPS if CPU_MIPS32_R2
 	select CRYPTO_POLY1305_MIPS if MIPS
 	select CRYPTO_CHACHA_S390 if S390
+	select CRYPTO_BLAKE2S_RISCV if RISCV && 64BIT
 	help
 	  WireGuard is a secure, fast, and easy to use replacement for IPSec
 	  that uses modern cryptography and clever networking tricks. It's
-- 
2.39.2




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