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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* ChaCha 256-bit cipher algorithm, x64 SSSE3 functions
*
* Copyright (C) 2015 Martin Willi
*/
#include <linux/linkage.h>
#include <asm/frame.h>
.section .rodata.cst16.ROT8, "aM", @progbits, 16
.align 16
ROT8: .octa 0x0e0d0c0f0a09080b0605040702010003
.section .rodata.cst16.ROT16, "aM", @progbits, 16
.align 16
ROT16: .octa 0x0d0c0f0e09080b0a0504070601000302
.section .rodata.cst16.CTRINC, "aM", @progbits, 16
.align 16
CTRINC: .octa 0x00000003000000020000000100000000
.text
/*
* chacha_permute - permute one block
*
* Permute one 64-byte block where the state matrix is in %xmm0-%xmm3. This
* function performs matrix operations on four words in parallel, but requires
* shuffling to rearrange the words after each round. 8/16-bit word rotation is
* done with the slightly better performing SSSE3 byte shuffling, 7/12-bit word
* rotation uses traditional shift+OR.
*
* The round count is given in %r8d.
*
* Clobbers: %r8d, %xmm4-%xmm7
*/
SYM_FUNC_START_LOCAL(chacha_permute)
movdqa ROT8(%rip),%xmm4
movdqa ROT16(%rip),%xmm5
.Ldoubleround:
# x0 += x1, x3 = rotl32(x3 ^ x0, 16)
paddd %xmm1,%xmm0
pxor %xmm0,%xmm3
pshufb %xmm5,%xmm3
# x2 += x3, x1 = rotl32(x1 ^ x2, 12)
paddd %xmm3,%xmm2
pxor %xmm2,%xmm1
movdqa %xmm1,%xmm6
pslld $12,%xmm6
psrld $20,%xmm1
por %xmm6,%xmm1
# x0 += x1, x3 = rotl32(x3 ^ x0, 8)
paddd %xmm1,%xmm0
pxor %xmm0,%xmm3
pshufb %xmm4,%xmm3
# x2 += x3, x1 = rotl32(x1 ^ x2, 7)
paddd %xmm3,%xmm2
pxor %xmm2,%xmm1
movdqa %xmm1,%xmm7
pslld $7,%xmm7
psrld $25,%xmm1
por %xmm7,%xmm1
# x1 = shuffle32(x1, MASK(0, 3, 2, 1))
pshufd $0x39,%xmm1,%xmm1
# x2 = shuffle32(x2, MASK(1, 0, 3, 2))
pshufd $0x4e,%xmm2,%xmm2
# x3 = shuffle32(x3, MASK(2, 1, 0, 3))
pshufd $0x93,%xmm3,%xmm3
# x0 += x1, x3 = rotl32(x3 ^ x0, 16)
paddd %xmm1,%xmm0
pxor %xmm0,%xmm3
pshufb %xmm5,%xmm3
# x2 += x3, x1 = rotl32(x1 ^ x2, 12)
paddd %xmm3,%xmm2
pxor %xmm2,%xmm1
movdqa %xmm1,%xmm6
pslld $12,%xmm6
psrld $20,%xmm1
por %xmm6,%xmm1
# x0 += x1, x3 = rotl32(x3 ^ x0, 8)
paddd %xmm1,%xmm0
pxor %xmm0,%xmm3
pshufb %xmm4,%xmm3
# x2 += x3, x1 = rotl32(x1 ^ x2, 7)
paddd %xmm3,%xmm2
pxor %xmm2,%xmm1
movdqa %xmm1,%xmm7
pslld $7,%xmm7
psrld $25,%xmm1
por %xmm7,%xmm1
# x1 = shuffle32(x1, MASK(2, 1, 0, 3))
pshufd $0x93,%xmm1,%xmm1
# x2 = shuffle32(x2, MASK(1, 0, 3, 2))
pshufd $0x4e,%xmm2,%xmm2
# x3 = shuffle32(x3, MASK(0, 3, 2, 1))
pshufd $0x39,%xmm3,%xmm3
sub $2,%r8d
jnz .Ldoubleround
ret
SYM_FUNC_END(chacha_permute)
SYM_FUNC_START(chacha_block_xor_ssse3)
# %rdi: Input state matrix, s
# %rsi: up to 1 data block output, o
# %rdx: up to 1 data block input, i
# %rcx: input/output length in bytes
# %r8d: nrounds
FRAME_BEGIN
# x0..3 = s0..3
movdqu 0x00(%rdi),%xmm0
movdqu 0x10(%rdi),%xmm1
movdqu 0x20(%rdi),%xmm2
movdqu 0x30(%rdi),%xmm3
movdqa %xmm0,%xmm8
movdqa %xmm1,%xmm9
movdqa %xmm2,%xmm10
movdqa %xmm3,%xmm11
mov %rcx,%rax
call chacha_permute
# o0 = i0 ^ (x0 + s0)
paddd %xmm8,%xmm0
cmp $0x10,%rax
jl .Lxorpart
movdqu 0x00(%rdx),%xmm4
pxor %xmm4,%xmm0
movdqu %xmm0,0x00(%rsi)
# o1 = i1 ^ (x1 + s1)
paddd %xmm9,%xmm1
movdqa %xmm1,%xmm0
cmp $0x20,%rax
jl .Lxorpart
movdqu 0x10(%rdx),%xmm0
pxor %xmm1,%xmm0
movdqu %xmm0,0x10(%rsi)
# o2 = i2 ^ (x2 + s2)
paddd %xmm10,%xmm2
movdqa %xmm2,%xmm0
cmp $0x30,%rax
jl .Lxorpart
movdqu 0x20(%rdx),%xmm0
pxor %xmm2,%xmm0
movdqu %xmm0,0x20(%rsi)
# o3 = i3 ^ (x3 + s3)
paddd %xmm11,%xmm3
movdqa %xmm3,%xmm0
cmp $0x40,%rax
jl .Lxorpart
movdqu 0x30(%rdx),%xmm0
pxor %xmm3,%xmm0
movdqu %xmm0,0x30(%rsi)
.Ldone:
FRAME_END
ret
.Lxorpart:
# xor remaining bytes from partial register into output
mov %rax,%r9
and $0x0f,%r9
jz .Ldone
and $~0x0f,%rax
mov %rsi,%r11
lea 8(%rsp),%r10
sub $0x10,%rsp
and $~31,%rsp
lea (%rdx,%rax),%rsi
mov %rsp,%rdi
mov %r9,%rcx
rep movsb
pxor 0x00(%rsp),%xmm0
movdqa %xmm0,0x00(%rsp)
mov %rsp,%rsi
lea (%r11,%rax),%rdi
mov %r9,%rcx
rep movsb
lea -8(%r10),%rsp
jmp .Ldone
SYM_FUNC_END(chacha_block_xor_ssse3)
SYM_FUNC_START(hchacha_block_ssse3)
# %rdi: Input state matrix, s
# %rsi: output (8 32-bit words)
# %edx: nrounds
FRAME_BEGIN
movdqu 0x00(%rdi),%xmm0
movdqu 0x10(%rdi),%xmm1
movdqu 0x20(%rdi),%xmm2
movdqu 0x30(%rdi),%xmm3
mov %edx,%r8d
call chacha_permute
movdqu %xmm0,0x00(%rsi)
movdqu %xmm3,0x10(%rsi)
FRAME_END
ret
SYM_FUNC_END(hchacha_block_ssse3)
SYM_FUNC_START(chacha_4block_xor_ssse3)
# %rdi: Input state matrix, s
# %rsi: up to 4 data blocks output, o
# %rdx: up to 4 data blocks input, i
# %rcx: input/output length in bytes
# %r8d: nrounds
# This function encrypts four consecutive ChaCha blocks by loading the
# the state matrix in SSE registers four times. As we need some scratch
# registers, we save the first four registers on the stack. The
# algorithm performs each operation on the corresponding word of each
# state matrix, hence requires no word shuffling. For final XORing step
# we transpose the matrix by interleaving 32- and then 64-bit words,
# which allows us to do XOR in SSE registers. 8/16-bit word rotation is
# done with the slightly better performing SSSE3 byte shuffling,
# 7/12-bit word rotation uses traditional shift+OR.
lea 8(%rsp),%r10
sub $0x80,%rsp
and $~63,%rsp
mov %rcx,%rax
# x0..15[0-3] = s0..3[0..3]
movq 0x00(%rdi),%xmm1
pshufd $0x00,%xmm1,%xmm0
pshufd $0x55,%xmm1,%xmm1
movq 0x08(%rdi),%xmm3
pshufd $0x00,%xmm3,%xmm2
pshufd $0x55,%xmm3,%xmm3
movq 0x10(%rdi),%xmm5
pshufd $0x00,%xmm5,%xmm4
pshufd
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