lib/crypto: riscv/poly1305: Import OpenSSL/CRYPTOGAMS implementation

This is a straight import of the OpenSSL/CRYPTOGAMS Poly1305
implementation for riscv authored by Andy Polyakov. The file
'poly1305-riscv.pl' is taken straight from
https://github.com/dot-asm/cryptogams commit
5e3fba73576244708a752fa61a8e93e587f271bb. This patch was tested on
SpacemiT X60, with 2~2.5x improvement over generic implementation.

Signed-off-by: Chunyan Zhang <[e-mail]>
Signed-off-by: Zhihang Shao <[e-mail]>
[EB: ported to lib/crypto/riscv/]
Reviewed-by: Ard Biesheuvel <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Eric Biggers <[e-mail]>

lib/crypto/Kconfig

···
 	default y if MIPS
 	# The PPC64 code needs to be fixed to work in softirq context.
 	default y if PPC64 && CPU_LITTLE_ENDIAN && VSX && BROKEN
+	default y if RISCV
 	default y if X86_64
 
 # This symbol controls the inclusion of the Poly1305 generic code.  This differs
···
 
 config CRYPTO_LIB_POLY1305_RSIZE
 	int
-	default 2 if MIPS
+	default 2 if MIPS || RISCV
 	default 11 if X86_64
 	default 9 if ARM || ARM64
 	default 1

lib/crypto/Makefile

···
 
 libpoly1305-$(CONFIG_PPC) += powerpc/poly1305-p10le_64.o
 
+ifeq ($(CONFIG_RISCV),y)
+libpoly1305-y += riscv/poly1305-core.o
+poly1305-perlasm-flavour-$(CONFIG_32BIT) := 32
+poly1305-perlasm-flavour-$(CONFIG_64BIT) := 64
+quiet_cmd_perlasm_poly1305 = PERLASM $@
+      cmd_perlasm_poly1305 = $(PERL) $< $(poly1305-perlasm-flavour-y) $@
+# Use if_changed instead of cmd, in case the flavour changed.
+$(obj)/riscv/poly1305-core.S: $(src)/riscv/poly1305-riscv.pl FORCE
+	$(call if_changed,perlasm_poly1305)
+targets += riscv/poly1305-core.S
+AFLAGS_riscv/poly1305-core.o += -Dpoly1305_init=poly1305_block_init
+endif
+
 ifeq ($(CONFIG_X86),y)
 libpoly1305-y += x86/poly1305-x86_64-cryptogams.o
 $(obj)/x86/poly1305-x86_64-cryptogams.S: $(src)/x86/poly1305-x86_64-cryptogams.pl
···
 clean-files += arm/poly1305-core.S \
 	       arm64/poly1305-core.S \
 	       mips/poly1305-core.S \
+	       riscv/poly1305-core.S \
 	       x86/poly1305-x86_64-cryptogams.S
 
 ################################################################################

lib/crypto/riscv/poly1305-riscv.pl

···
+#!/usr/bin/env perl
+# SPDX-License-Identifier: GPL-1.0+ OR BSD-3-Clause
+#
+# ====================================================================
+# Written by Andy Polyakov, @dot-asm, initially for use with OpenSSL.
+# ====================================================================
+#
+# Poly1305 hash for RISC-V.
+#
+# February 2019
+#
+# In the essence it's pretty straightforward transliteration of MIPS
+# module [without big-endian option].
+#
+# 1.8 cycles per byte on U74, >100% faster than compiler-generated
+# code. 1.9 cpb on C910, ~75% improvement. 3.3 on Spacemit X60, ~69%
+# improvement.
+#
+# June 2024.
+#
+# Add CHERI support.
+#
+######################################################################
+#
+($zero,$ra,$sp,$gp,$tp)=map("x$_",(0..4));
+($t0,$t1,$t2,$t3,$t4,$t5,$t6)=map("x$_",(5..7,28..31));
+($a0,$a1,$a2,$a3,$a4,$a5,$a6,$a7)=map("x$_",(10..17));
+($s0,$s1,$s2,$s3,$s4,$s5,$s6,$s7,$s8,$s9,$s10,$s11)=map("x$_",(8,9,18..27));
+#
+######################################################################
+
+$flavour = shift || "64";
+
+for (@ARGV) {   $output=$_ if (/\w[\w\-]*\.\w+$/);   }
+open STDOUT,">$output";
+
+$code.=<<___;
+#ifdef __KERNEL__
+# ifdef __riscv_zicfilp
+#  undef __riscv_zicfilp // calls are expected to be direct
+# endif
+#endif
+
+#if defined(__CHERI_PURE_CAPABILITY__) && !defined(__riscv_misaligned_fast)
+# define __riscv_misaligned_fast 1
+#endif
+___
+
+if ($flavour =~ /64/) {{{
+######################################################################
+# 64-bit code path...
+#
+my ($ctx,$inp,$len,$padbit) = ($a0,$a1,$a2,$a3);
+my ($in0,$in1,$tmp0,$tmp1,$tmp2,$tmp3,$tmp4) = ($a4,$a5,$a6,$a7,$t0,$t1,$t2);
+
+$code.=<<___;
+#if __riscv_xlen == 64
+# if __SIZEOF_POINTER__ == 16
+#  define PUSH	csc
+#  define POP	clc
+# else
+#  define PUSH	sd
+#  define POP	ld
+# endif
+#else
+# error "unsupported __riscv_xlen"
+#endif
+
+.option	pic
+.text
+
+.globl	poly1305_init
+.type	poly1305_init,\@function
+poly1305_init:
+#ifdef	__riscv_zicfilp
+	lpad	0
+#endif
+	sd	$zero,0($ctx)
+	sd	$zero,8($ctx)
+	sd	$zero,16($ctx)
+
+	beqz	$inp,.Lno_key
+
+#ifndef	__riscv_misaligned_fast
+	andi	$tmp0,$inp,7		# $inp % 8
+	andi	$inp,$inp,-8		# align $inp
+	slli	$tmp0,$tmp0,3		# byte to bit offset
+#endif
+	ld	$in0,0($inp)
+	ld	$in1,8($inp)
+#ifndef	__riscv_misaligned_fast
+	beqz	$tmp0,.Laligned_key
+
+	ld	$tmp2,16($inp)
+	neg	$tmp1,$tmp0		# implicit &63 in sll
+	srl	$in0,$in0,$tmp0
+	sll	$tmp3,$in1,$tmp1
+	srl	$in1,$in1,$tmp0
+	sll	$tmp2,$tmp2,$tmp1
+	or	$in0,$in0,$tmp3
+	or	$in1,$in1,$tmp2
+
+.Laligned_key:
+#endif
+	li	$tmp0,1
+	slli	$tmp0,$tmp0,32		# 0x0000000100000000
+	addi	$tmp0,$tmp0,-63		# 0x00000000ffffffc1
+	slli	$tmp0,$tmp0,28		# 0x0ffffffc10000000
+	addi	$tmp0,$tmp0,-1		# 0x0ffffffc0fffffff
+
+	and	$in0,$in0,$tmp0
+	addi	$tmp0,$tmp0,-3		# 0x0ffffffc0ffffffc
+	and	$in1,$in1,$tmp0
+
+	sd	$in0,24($ctx)
+	srli	$tmp0,$in1,2
+	sd	$in1,32($ctx)
+	add	$tmp0,$tmp0,$in1	# s1 = r1 + (r1 >> 2)
+	sd	$tmp0,40($ctx)
+
+.Lno_key:
+	li	$a0,0			# return 0
+	ret
+.size	poly1305_init,.-poly1305_init
+___
+{
+my ($h0,$h1,$h2,$r0,$r1,$rs1,$d0,$d1,$d2) =
+   ($s0,$s1,$s2,$s3,$t3,$t4,$in0,$in1,$t2);
+my ($shr,$shl) = ($t5,$t6);		# used on R6
+
+$code.=<<___;
+.globl	poly1305_blocks
+.type	poly1305_blocks,\@function
+poly1305_blocks:
+#ifdef	__riscv_zicfilp
+	lpad	0
+#endif
+	andi	$len,$len,-16		# complete blocks only
+	beqz	$len,.Lno_data
+
+	caddi	$sp,$sp,-4*__SIZEOF_POINTER__
+	PUSH	$s0,3*__SIZEOF_POINTER__($sp)
+	PUSH	$s1,2*__SIZEOF_POINTER__($sp)
+	PUSH	$s2,1*__SIZEOF_POINTER__($sp)
+	PUSH	$s3,0*__SIZEOF_POINTER__($sp)
+
+#ifndef	__riscv_misaligned_fast
+	andi	$shr,$inp,7
+	andi	$inp,$inp,-8		# align $inp
+	slli	$shr,$shr,3		# byte to bit offset
+	neg	$shl,$shr		# implicit &63 in sll
+#endif
+
+	ld	$h0,0($ctx)		# load hash value
+	ld	$h1,8($ctx)
+	ld	$h2,16($ctx)
+
+	ld	$r0,24($ctx)		# load key
+	ld	$r1,32($ctx)
+	ld	$rs1,40($ctx)
+
+	add	$len,$len,$inp		# end of buffer
+
+.Loop:
+	ld	$in0,0($inp)		# load input
+	ld	$in1,8($inp)
+#ifndef	__riscv_misaligned_fast
+	beqz	$shr,.Laligned_inp
+
+	ld	$tmp2,16($inp)
+	srl	$in0,$in0,$shr
+	sll	$tmp3,$in1,$shl
+	srl	$in1,$in1,$shr
+	sll	$tmp2,$tmp2,$shl
+	or	$in0,$in0,$tmp3
+	or	$in1,$in1,$tmp2
+
+.Laligned_inp:
+#endif
+	caddi	$inp,$inp,16
+
+	andi	$tmp0,$h2,-4		# modulo-scheduled reduction
+	srli	$tmp1,$h2,2
+	andi	$h2,$h2,3
+
+	add	$d0,$h0,$in0		# accumulate input
+	 add	$tmp1,$tmp1,$tmp0
+	sltu	$tmp0,$d0,$h0
+	add	$d0,$d0,$tmp1		# ... and residue
+	sltu	$tmp1,$d0,$tmp1
+	add	$d1,$h1,$in1
+	add	$tmp0,$tmp0,$tmp1
+	sltu	$tmp1,$d1,$h1
+	add	$d1,$d1,$tmp0
+
+	 add	$d2,$h2,$padbit
+	 sltu	$tmp0,$d1,$tmp0
+	mulhu	$h1,$r0,$d0		# h0*r0
+	mul	$h0,$r0,$d0
+
+	 add	$d2,$d2,$tmp1
+	 add	$d2,$d2,$tmp0
+	mulhu	$tmp1,$rs1,$d1		# h1*5*r1
+	mul	$tmp0,$rs1,$d1
+
+	mulhu	$h2,$r1,$d0		# h0*r1
+	mul	$tmp2,$r1,$d0
+	 add	$h0,$h0,$tmp0
+	 add	$h1,$h1,$tmp1
+	 sltu	$tmp0,$h0,$tmp0
+
+	 add	$h1,$h1,$tmp0
+	 add	$h1,$h1,$tmp2
+	mulhu	$tmp1,$r0,$d1		# h1*r0
+	mul	$tmp0,$r0,$d1
+
+	 sltu	$tmp2,$h1,$tmp2
+	 add	$h2,$h2,$tmp2
+	mul	$tmp2,$rs1,$d2		# h2*5*r1
+
+	 add	$h1,$h1,$tmp0
+	 add	$h2,$h2,$tmp1
+	mul	$tmp3,$r0,$d2		# h2*r0
+	 sltu	$tmp0,$h1,$tmp0
+	 add	$h2,$h2,$tmp0
+
+	add	$h1,$h1,$tmp2
+	sltu	$tmp2,$h1,$tmp2
+	add	$h2,$h2,$tmp2
+	add	$h2,$h2,$tmp3
+
+	bne	$inp,$len,.Loop
+
+	sd	$h0,0($ctx)		# store hash value
+	sd	$h1,8($ctx)
+	sd	$h2,16($ctx)
+
+	POP	$s0,3*__SIZEOF_POINTER__($sp)		# epilogue
+	POP	$s1,2*__SIZEOF_POINTER__($sp)
+	POP	$s2,1*__SIZEOF_POINTER__($sp)
+	POP	$s3,0*__SIZEOF_POINTER__($sp)
+	caddi	$sp,$sp,4*__SIZEOF_POINTER__
+
+.Lno_data:
+	ret
+.size	poly1305_blocks,.-poly1305_blocks
+___
+}
+{
+my ($ctx,$mac,$nonce) = ($a0,$a1,$a2);
+
+$code.=<<___;
+.globl	poly1305_emit
+.type	poly1305_emit,\@function
+poly1305_emit:
+#ifdef	__riscv_zicfilp
+	lpad	0
+#endif
+	ld	$tmp2,16($ctx)
+	ld	$tmp0,0($ctx)
+	ld	$tmp1,8($ctx)
+
+	andi	$in0,$tmp2,-4		# final reduction
+	srl	$in1,$tmp2,2
+	andi	$tmp2,$tmp2,3
+	add	$in0,$in0,$in1
+
+	add	$tmp0,$tmp0,$in0
+	sltu	$in1,$tmp0,$in0
+	 addi	$in0,$tmp0,5		# compare to modulus
+	add	$tmp1,$tmp1,$in1
+	 sltiu	$tmp3,$in0,5
+	sltu	$tmp4,$tmp1,$in1
+	 add	$in1,$tmp1,$tmp3
+	add	$tmp2,$tmp2,$tmp4
+	 sltu	$tmp3,$in1,$tmp3
+	 add	$tmp2,$tmp2,$tmp3
+
+	srli	$tmp2,$tmp2,2		# see if it carried/borrowed
+	neg	$tmp2,$tmp2
+
+	xor	$in0,$in0,$tmp0
+	xor	$in1,$in1,$tmp1
+	and	$in0,$in0,$tmp2
+	and	$in1,$in1,$tmp2
+	xor	$in0,$in0,$tmp0
+	xor	$in1,$in1,$tmp1
+
+	lwu	$tmp0,0($nonce)		# load nonce
+	lwu	$tmp1,4($nonce)
+	lwu	$tmp2,8($nonce)
+	lwu	$tmp3,12($nonce)
+	slli	$tmp1,$tmp1,32
+	slli	$tmp3,$tmp3,32
+	or	$tmp0,$tmp0,$tmp1
+	or	$tmp2,$tmp2,$tmp3
+
+	add	$in0,$in0,$tmp0		# accumulate nonce
+	add	$in1,$in1,$tmp2
+	sltu	$tmp0,$in0,$tmp0
+	add	$in1,$in1,$tmp0
+
+#ifdef	__riscv_misaligned_fast
+	sd	$in0,0($mac)		# write mac value
+	sd	$in1,8($mac)
+#else
+	srli	$tmp0,$in0,8		# write mac value
+	srli	$tmp1,$in0,16
+	srli	$tmp2,$in0,24
+	sb	$in0,0($mac)
+	srli	$tmp3,$in0,32
+	sb	$tmp0,1($mac)
+	srli	$tmp0,$in0,40
+	sb	$tmp1,2($mac)
+	srli	$tmp1,$in0,48
+	sb	$tmp2,3($mac)
+	srli	$tmp2,$in0,56
+	sb	$tmp3,4($mac)
+	srli	$tmp3,$in1,8
+	sb	$tmp0,5($mac)
+	srli	$tmp0,$in1,16
+	sb	$tmp1,6($mac)
+	srli	$tmp1,$in1,24
+	sb	$tmp2,7($mac)
+
+	sb	$in1,8($mac)
+	srli	$tmp2,$in1,32
+	sb	$tmp3,9($mac)
+	srli	$tmp3,$in1,40
+	sb	$tmp0,10($mac)
+	srli	$tmp0,$in1,48
+	sb	$tmp1,11($mac)
+	srli	$tmp1,$in1,56
+	sb	$tmp2,12($mac)
+	sb	$tmp3,13($mac)
+	sb	$tmp0,14($mac)
+	sb	$tmp1,15($mac)
+#endif
+
+	ret
+.size	poly1305_emit,.-poly1305_emit
+.string	"Poly1305 for RISC-V, CRYPTOGAMS by \@dot-asm"
+___
+}
+}}} else {{{
+######################################################################
+# 32-bit code path
+#
+
+my ($ctx,$inp,$len,$padbit) = ($a0,$a1,$a2,$a3);
+my ($in0,$in1,$in2,$in3,$tmp0,$tmp1,$tmp2,$tmp3) =
+   ($a4,$a5,$a6,$a7,$t0,$t1,$t2,$t3);
+
+$code.=<<___;
+#if __riscv_xlen == 32
+# if __SIZEOF_POINTER__ == 8
+#  define PUSH	csc
+#  define POP	clc
+# else
+#  define PUSH	sw
+#  define POP	lw
+# endif
+# define MULX(hi,lo,a,b)	mulhu hi,a,b; mul lo,a,b
+# define srliw	srli
+# define srlw	srl
+# define sllw	sll
+# define addw	add
+# define addiw	addi
+# define mulw	mul
+#elif __riscv_xlen == 64
+# if __SIZEOF_POINTER__ == 16
+#  define PUSH	csc
+#  define POP	clc
+# else
+#  define PUSH	sd
+#  define POP	ld
+# endif
+# define MULX(hi,lo,a,b)	slli b,b,32; srli b,b,32; mul hi,a,b; addiw lo,hi,0; srai hi,hi,32
+#else
+# error "unsupported __riscv_xlen"
+#endif
+
+.option	pic
+.text
+
+.globl	poly1305_init
+.type	poly1305_init,\@function
+poly1305_init:
+#ifdef	__riscv_zicfilp
+	lpad	0
+#endif
+	sw	$zero,0($ctx)
+	sw	$zero,4($ctx)
+	sw	$zero,8($ctx)
+	sw	$zero,12($ctx)
+	sw	$zero,16($ctx)
+
+	beqz	$inp,.Lno_key
+
+#ifndef	__riscv_misaligned_fast
+	andi	$tmp0,$inp,3		# $inp % 4
+	sub	$inp,$inp,$tmp0		# align $inp
+	sll	$tmp0,$tmp0,3		# byte to bit offset
+#endif
+	lw	$in0,0($inp)
+	lw	$in1,4($inp)
+	lw	$in2,8($inp)
+	lw	$in3,12($inp)
+#ifndef	__riscv_misaligned_fast
+	beqz	$tmp0,.Laligned_key
+
+	lw	$tmp2,16($inp)
+	sub	$tmp1,$zero,$tmp0
+	srlw	$in0,$in0,$tmp0
+	sllw	$tmp3,$in1,$tmp1
+	srlw	$in1,$in1,$tmp0
+	or	$in0,$in0,$tmp3
+	sllw	$tmp3,$in2,$tmp1
+	srlw	$in2,$in2,$tmp0
+	or	$in1,$in1,$tmp3
+	sllw	$tmp3,$in3,$tmp1
+	srlw	$in3,$in3,$tmp0
+	or	$in2,$in2,$tmp3
+	sllw	$tmp2,$tmp2,$tmp1
+	or	$in3,$in3,$tmp2
+.Laligned_key:
+#endif
+
+	lui	$tmp0,0x10000
+	addi	$tmp0,$tmp0,-1		# 0x0fffffff
+	and	$in0,$in0,$tmp0
+	addi	$tmp0,$tmp0,-3		# 0x0ffffffc
+	and	$in1,$in1,$tmp0
+	and	$in2,$in2,$tmp0
+	and	$in3,$in3,$tmp0
+
+	sw	$in0,20($ctx)
+	sw	$in1,24($ctx)
+	sw	$in2,28($ctx)
+	sw	$in3,32($ctx)
+
+	srlw	$tmp1,$in1,2
+	srlw	$tmp2,$in2,2
+	srlw	$tmp3,$in3,2
+	addw	$in1,$in1,$tmp1		# s1 = r1 + (r1 >> 2)
+	addw	$in2,$in2,$tmp2
+	addw	$in3,$in3,$tmp3
+	sw	$in1,36($ctx)
+	sw	$in2,40($ctx)
+	sw	$in3,44($ctx)
+.Lno_key:
+	li	$a0,0
+	ret
+.size	poly1305_init,.-poly1305_init
+___
+{
+my ($h0,$h1,$h2,$h3,$h4, $r0,$r1,$r2,$r3, $rs1,$rs2,$rs3) =
+   ($s0,$s1,$s2,$s3,$s4, $s5,$s6,$s7,$s8, $t0,$t1,$t2);
+my ($d0,$d1,$d2,$d3) =
+   ($a4,$a5,$a6,$a7);
+my $shr = $ra;		# used on R6
+
+$code.=<<___;
+.globl	poly1305_blocks
+.type	poly1305_blocks,\@function
+poly1305_blocks:
+#ifdef	__riscv_zicfilp
+	lpad	0
+#endif
+	andi	$len,$len,-16		# complete blocks only
+	beqz	$len,.Labort
+
+#ifdef	__riscv_zcmp
+	cm.push	{ra,s0-s8}, -48
+#else
+	caddi	$sp,$sp,-__SIZEOF_POINTER__*12
+	PUSH	$ra, __SIZEOF_POINTER__*11($sp)
+	PUSH	$s0, __SIZEOF_POINTER__*10($sp)
+	PUSH	$s1, __SIZEOF_POINTER__*9($sp)
+	PUSH	$s2, __SIZEOF_POINTER__*8($sp)
+	PUSH	$s3, __SIZEOF_POINTER__*7($sp)
+	PUSH	$s4, __SIZEOF_POINTER__*6($sp)
+	PUSH	$s5, __SIZEOF_POINTER__*5($sp)
+	PUSH	$s6, __SIZEOF_POINTER__*4($sp)
+	PUSH	$s7, __SIZEOF_POINTER__*3($sp)
+	PUSH	$s8, __SIZEOF_POINTER__*2($sp)
+#endif
+
+#ifndef	__riscv_misaligned_fast
+	andi	$shr,$inp,3
+	andi	$inp,$inp,-4		# align $inp
+	slli	$shr,$shr,3		# byte to bit offset
+#endif
+
+	lw	$h0,0($ctx)		# load hash value
+	lw	$h1,4($ctx)
+	lw	$h2,8($ctx)
+	lw	$h3,12($ctx)
+	lw	$h4,16($ctx)
+
+	lw	$r0,20($ctx)		# load key
+	lw	$r1,24($ctx)
+	lw	$r2,28($ctx)
+	lw	$r3,32($ctx)
+	lw	$rs1,36($ctx)
+	lw	$rs2,40($ctx)
+	lw	$rs3,44($ctx)
+
+	add	$len,$len,$inp		# end of buffer
+
+.Loop:
+	lw	$d0,0($inp)		# load input
+	lw	$d1,4($inp)
+	lw	$d2,8($inp)
+	lw	$d3,12($inp)
+#ifndef	__riscv_misaligned_fast
+	beqz	$shr,.Laligned_inp
+
+	lw	$t4,16($inp)
+	sub	$t5,$zero,$shr
+	srlw	$d0,$d0,$shr
+	sllw	$t3,$d1,$t5
+	srlw	$d1,$d1,$shr
+	or	$d0,$d0,$t3
+	sllw	$t3,$d2,$t5
+	srlw	$d2,$d2,$shr
+	or	$d1,$d1,$t3
+	sllw	$t3,$d3,$t5
+	srlw	$d3,$d3,$shr
+	or	$d2,$d2,$t3
+	sllw	$t4,$t4,$t5
+	or	$d3,$d3,$t4
+
+.Laligned_inp:
+#endif
+	srliw	$t3,$h4,2		# modulo-scheduled reduction
+	andi	$t4,$h4,-4
+	andi	$h4,$h4,3
+
+	addw	$d0,$d0,$h0		# accumulate input
+	 addw	$t4,$t4,$t3
+	sltu	$h0,$d0,$h0
+	addw	$d0,$d0,$t4		# ... and residue
+	sltu	$t4,$d0,$t4
+
+	addw	$d1,$d1,$h1
+	 addw	$h0,$h0,$t4		# carry
+	sltu	$h1,$d1,$h1
+	addw	$d1,$d1,$h0
+	sltu	$h0,$d1,$h0
+
+	addw	$d2,$d2,$h2
+	 addw	$h1,$h1,$h0		# carry
+	sltu	$h2,$d2,$h2
+	addw	$d2,$d2,$h1
+	sltu	$h1,$d2,$h1
+
+	addw	$d3,$d3,$h3
+	 addw	$h2,$h2,$h1		# carry
+	sltu	$h3,$d3,$h3
+	addw	$d3,$d3,$h2
+
+	MULX	($h1,$h0,$r0,$d0)	# d0*r0
+
+	 sltu	$h2,$d3,$h2
+	 addw	$h3,$h3,$h2		# carry
+
+	MULX	($t4,$t3,$rs3,$d1)	# d1*s3
+
+	 addw	$h4,$h4,$padbit
+	 caddi	$inp,$inp,16
+	 addw	$h4,$h4,$h3
+
+	MULX	($t6,$a3,$rs2,$d2)	# d2*s2
+	 addw	$h0,$h0,$t3
+	 addw	$h1,$h1,$t4
+	 sltu	$t3,$h0,$t3
+	 addw	$h1,$h1,$t3
+
+	MULX	($t4,$t3,$rs1,$d3)	# d3*s1
+	 addw	$h0,$h0,$a3
+	 addw	$h1,$h1,$t6
+	 sltu	$a3,$h0,$a3
+	 addw	$h1,$h1,$a3
+
+
+	MULX	($h2,$a3,$r1,$d0)	# d0*r1
+	 addw	$h0,$h0,$t3
+	 addw	$h1,$h1,$t4
+	 sltu	$t3,$h0,$t3
+	 addw	$h1,$h1,$t3
+
+	MULX	($t4,$t3,$r0,$d1)	# d1*r0
+	 addw	$h1,$h1,$a3
+	 sltu	$a3,$h1,$a3
+	 addw	$h2,$h2,$a3
+
+	MULX	($t6,$a3,$rs3,$d2)	# d2*s3
+	 addw	$h1,$h1,$t3
+	 addw	$h2,$h2,$t4
+	 sltu	$t3,$h1,$t3
+	 addw	$h2,$h2,$t3
+
+	MULX	($t4,$t3,$rs2,$d3)	# d3*s2
+	 addw	$h1,$h1,$a3
+	 addw	$h2,$h2,$t6
+	 sltu	$a3,$h1,$a3
+	 addw	$h2,$h2,$a3
+
+	mulw	$a3,$rs1,$h4		# h4*s1
+	 addw	$h1,$h1,$t3
+	 addw	$h2,$h2,$t4
+	 sltu	$t3,$h1,$t3
+	 addw	$h2,$h2,$t3
+
+
+	MULX	($h3,$t3,$r2,$d0)	# d0*r2
+	 addw	$h1,$h1,$a3
+	 sltu	$a3,$h1,$a3
+	 addw	$h2,$h2,$a3
+
+	MULX	($t6,$a3,$r1,$d1)	# d1*r1
+	 addw	$h2,$h2,$t3
+	 sltu	$t3,$h2,$t3
+	 addw	$h3,$h3,$t3
+
+	MULX	($t4,$t3,$r0,$d2)	# d2*r0
+	 addw	$h2,$h2,$a3
+	 addw	$h3,$h3,$t6
+	 sltu	$a3,$h2,$a3
+	 addw	$h3,$h3,$a3
+
+	MULX	($t6,$a3,$rs3,$d3)	# d3*s3
+	 addw	$h2,$h2,$t3
+	 addw	$h3,$h3,$t4
+	 sltu	$t3,$h2,$t3
+	 addw	$h3,$h3,$t3
+
+	mulw	$t3,$rs2,$h4		# h4*s2
+	 addw	$h2,$h2,$a3
+	 addw	$h3,$h3,$t6
+	 sltu	$a3,$h2,$a3
+	 addw	$h3,$h3,$a3
+
+
+	MULX	($t6,$a3,$r3,$d0)	# d0*r3
+	 addw	$h2,$h2,$t3
+	 sltu	$t3,$h2,$t3
+	 addw	$h3,$h3,$t3
+
+	MULX	($t4,$t3,$r2,$d1)	# d1*r2
+	 addw	$h3,$h3,$a3
+	 sltu	$a3,$h3,$a3
+	 addw	$t6,$t6,$a3
+
+	MULX	($a3,$d3,$r0,$d3)	# d3*r0
+	 addw	$h3,$h3,$t3
+	 addw	$t6,$t6,$t4
+	 sltu	$t3,$h3,$t3
+	 addw	$t6,$t6,$t3
+
+	MULX	($t4,$t3,$r1,$d2)	# d2*r1
+	 addw	$h3,$h3,$d3
+	 addw	$t6,$t6,$a3
+	 sltu	$d3,$h3,$d3
+	 addw	$t6,$t6,$d3
+
+	mulw	$a3,$rs3,$h4		# h4*s3
+	 addw	$h3,$h3,$t3
+	 addw	$t6,$t6,$t4
+	 sltu	$t3,$h3,$t3
+	 addw	$t6,$t6,$t3
+
+
+	mulw	$h4,$r0,$h4		# h4*r0
+	 addw	$h3,$h3,$a3
+	 sltu	$a3,$h3,$a3
+	 addw	$t6,$t6,$a3
+	addw	$h4,$t6,$h4
+
+	li	$padbit,1		# if we loop, padbit is 1
+
+	bne	$inp,$len,.Loop
+
+	sw	$h0,0($ctx)		# store hash value
+	sw	$h1,4($ctx)
+	sw	$h2,8($ctx)
+	sw	$h3,12($ctx)
+	sw	$h4,16($ctx)
+
+#ifdef	__riscv_zcmp
+	cm.popret	{ra,s0-s8}, 48
+#else
+	POP	$ra, __SIZEOF_POINTER__*11($sp)
+	POP	$s0, __SIZEOF_POINTER__*10($sp)
+	POP	$s1, __SIZEOF_POINTER__*9($sp)
+	POP	$s2, __SIZEOF_POINTER__*8($sp)
+	POP	$s3, __SIZEOF_POINTER__*7($sp)
+	POP	$s4, __SIZEOF_POINTER__*6($sp)
+	POP	$s5, __SIZEOF_POINTER__*5($sp)
+	POP	$s6, __SIZEOF_POINTER__*4($sp)
+	POP	$s7, __SIZEOF_POINTER__*3($sp)
+	POP	$s8, __SIZEOF_POINTER__*2($sp)
+	caddi	$sp,$sp,__SIZEOF_POINTER__*12
+#endif
+.Labort:
+	ret
+.size	poly1305_blocks,.-poly1305_blocks
+___
+}
+{
+my ($ctx,$mac,$nonce,$tmp4) = ($a0,$a1,$a2,$a3);
+
+$code.=<<___;
+.globl	poly1305_emit
+.type	poly1305_emit,\@function
+poly1305_emit:
+#ifdef	__riscv_zicfilp
+	lpad	0
+#endif
+	lw	$tmp4,16($ctx)
+	lw	$tmp0,0($ctx)
+	lw	$tmp1,4($ctx)
+	lw	$tmp2,8($ctx)
+	lw	$tmp3,12($ctx)
+
+	srliw	$ctx,$tmp4,2		# final reduction
+	andi	$in0,$tmp4,-4
+	andi	$tmp4,$tmp4,3
+	addw	$ctx,$ctx,$in0
+
+	addw	$tmp0,$tmp0,$ctx
+	sltu	$ctx,$tmp0,$ctx
+	 addiw	$in0,$tmp0,5		# compare to modulus
+	addw	$tmp1,$tmp1,$ctx
+	 sltiu	$in1,$in0,5
+	sltu	$ctx,$tmp1,$ctx
+	 addw	$in1,$in1,$tmp1
+	addw	$tmp2,$tmp2,$ctx
+	 sltu	$in2,$in1,$tmp1
+	sltu	$ctx,$tmp2,$ctx
+	 addw	$in2,$in2,$tmp2
+	addw	$tmp3,$tmp3,$ctx
+	 sltu	$in3,$in2,$tmp2
+	sltu	$ctx,$tmp3,$ctx
+	 addw	$in3,$in3,$tmp3
+	addw	$tmp4,$tmp4,$ctx
+	 sltu	$ctx,$in3,$tmp3
+	 addw	$ctx,$ctx,$tmp4
+
+	srl	$ctx,$ctx,2		# see if it carried/borrowed
+	sub	$ctx,$zero,$ctx
+
+	xor	$in0,$in0,$tmp0
+	xor	$in1,$in1,$tmp1
+	xor	$in2,$in2,$tmp2
+	xor	$in3,$in3,$tmp3
+	and	$in0,$in0,$ctx
+	and	$in1,$in1,$ctx
+	and	$in2,$in2,$ctx
+	and	$in3,$in3,$ctx
+	xor	$in0,$in0,$tmp0
+	xor	$in1,$in1,$tmp1
+	xor	$in2,$in2,$tmp2
+	xor	$in3,$in3,$tmp3
+
+	lw	$tmp0,0($nonce)		# load nonce
+	lw	$tmp1,4($nonce)
+	lw	$tmp2,8($nonce)
+	lw	$tmp3,12($nonce)
+
+	addw	$in0,$in0,$tmp0		# accumulate nonce
+	sltu	$ctx,$in0,$tmp0
+
+	addw	$in1,$in1,$tmp1
+	sltu	$tmp1,$in1,$tmp1
+	addw	$in1,$in1,$ctx
+	sltu	$ctx,$in1,$ctx
+	addw	$ctx,$ctx,$tmp1
+
+	addw	$in2,$in2,$tmp2
+	sltu	$tmp2,$in2,$tmp2
+	addw	$in2,$in2,$ctx
+	sltu	$ctx,$in2,$ctx
+	addw	$ctx,$ctx,$tmp2
+
+	addw	$in3,$in3,$tmp3
+	addw	$in3,$in3,$ctx
+
+#ifdef	__riscv_misaligned_fast
+	sw	$in0,0($mac)		# write mac value
+	sw	$in1,4($mac)
+	sw	$in2,8($mac)
+	sw	$in3,12($mac)
+#else
+	srl	$tmp0,$in0,8		# write mac value
+	srl	$tmp1,$in0,16
+	srl	$tmp2,$in0,24
+	sb	$in0, 0($mac)
+	sb	$tmp0,1($mac)
+	srl	$tmp0,$in1,8
+	sb	$tmp1,2($mac)
+	srl	$tmp1,$in1,16
+	sb	$tmp2,3($mac)
+	srl	$tmp2,$in1,24
+	sb	$in1, 4($mac)
+	sb	$tmp0,5($mac)
+	srl	$tmp0,$in2,8
+	sb	$tmp1,6($mac)
+	srl	$tmp1,$in2,16
+	sb	$tmp2,7($mac)
+	srl	$tmp2,$in2,24
+	sb	$in2, 8($mac)
+	sb	$tmp0,9($mac)
+	srl	$tmp0,$in3,8
+	sb	$tmp1,10($mac)
+	srl	$tmp1,$in3,16
+	sb	$tmp2,11($mac)
+	srl	$tmp2,$in3,24
+	sb	$in3, 12($mac)
+	sb	$tmp0,13($mac)
+	sb	$tmp1,14($mac)
+	sb	$tmp2,15($mac)
+#endif
+
+	ret
+.size	poly1305_emit,.-poly1305_emit
+.string	"Poly1305 for RISC-V, CRYPTOGAMS by \@dot-asm"
+___
+}
+}}}
+
+foreach (split("\n", $code)) {
+    if ($flavour =~ /^cheri/) {
+	s/\(x([0-9]+)\)/(c$1)/ and s/\b([ls][bhwd]u?)\b/c$1/;
+	s/\b(PUSH|POP)(\s+)x([0-9]+)/$1$2c$3/ or
+	s/\b(ret|jal)\b/c$1/;
+	s/\bcaddi?\b/cincoffset/ and s/\bx([0-9]+,)/c$1/g or
+	m/\bcmove\b/ and s/\bx([0-9]+)/c$1/g;
+    } else {
+	s/\bcaddi?\b/add/ or
+	s/\bcmove\b/mv/;
+    }
+    print $_, "\n";
+}
+
+close STDOUT;

lib/crypto/riscv/poly1305.h

···
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * OpenSSL/Cryptogams accelerated Poly1305 transform for riscv
+ *
+ * Copyright (C) 2025 Institute of Software, CAS.
+ */
+
+asmlinkage void poly1305_block_init(struct poly1305_block_state *state,
+				    const u8 raw_key[POLY1305_BLOCK_SIZE]);
+asmlinkage void poly1305_blocks(struct poly1305_block_state *state,
+				const u8 *src, u32 len, u32 hibit);
+asmlinkage void poly1305_emit(const struct poly1305_state *state,
+			      u8 digest[POLY1305_DIGEST_SIZE],
+			      const u32 nonce[4]);