/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* BLAKE2b digest algorithm, NEON accelerated
*
* Copyright 2020 Google LLC
*
* Author: Eric Biggers <ebiggers@google.com>
*/
#include <linux/linkage.h>
.text
.fpu neon
// The arguments to blake2b_compress_neon()
STATE .req r0
BLOCK .req r1
NBLOCKS .req r2
INC .req r3
// Pointers to the rotation tables
ROR24_TABLE .req r4
ROR16_TABLE .req r5
// The original stack pointer
ORIG_SP .req r6
// NEON registers which contain the message words of the current block.
// M_0-M_3 are occasionally used for other purposes too.
M_0 .req d16
M_1 .req d17
M_2 .req d18
M_3 .req d19
M_4 .req d20
M_5 .req d21
M_6 .req d22
M_7 .req d23
M_8 .req d24
M_9 .req d25
M_10 .req d26
M_11 .req d27
M_12 .req d28
M_13 .req d29
M_14 .req d30
M_15 .req d31
.align 4
// Tables for computing ror64(x, 24) and ror64(x, 16) using the vtbl.8
// instruction. This is the most efficient way to implement these
// rotation amounts with NEON. (On Cortex-A53 it's the same speed as
// vshr.u64 + vsli.u64, while on Cortex-A7 it's faster.)
.Lror24_table:
.byte 3, 4, 5, 6, 7, 0, 1, 2
.Lror16_table:
.byte 2, 3, 4, 5, 6, 7, 0, 1
// The BLAKE2b initialization vector
.Lblake2b_IV:
.quad 0x6a09e667f3bcc908, 0xbb67ae8584caa73b
.quad 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1
.quad 0x510e527fade682d1, 0x9b05688c2b3e6c1f
.quad 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179
// Execute one round of BLAKE2b by updating the state matrix v[0..15] in the
// NEON registers q0-q7. The message block is in q8..q15 (M_0-M_15). The stack
// pointer points to a 32-byte aligned buffer containing a copy of q8 and q9
// (M_0-M_3), so that they can be reloaded if they are used as temporary
// registers. The macro arguments s0-s15 give the order in which the message
// words are used in this round. 'final' is 1 if this is the final round.
.macro _blake2b_round s0, s1, s2, s3, s4, s5, s6, s7, \
s8, s9, s10, s11, s12, s13, s14, s15, final=0
// Mix the columns:
// (v[0], v[4], v[8], v[12]), (v[1], v[5], v[9], v[13]),
// (v[2], v[6], v[10], v[14]), and (v[3], v[7], v[11], v[15]).
// a += b + m[blake2b_sigma[r][2*i + 0]];
vadd.u64 q0, q0, q2
vadd.u64 q1, q1, q3
vadd.u64 d0, d0, M_\s0
vadd.u64 d1, d1, M_\s2
vadd.u64 d2, d2, M_\s4
vadd.u64 d3, d3, M_\s6
// d = ror64(d ^ a, 32);
veor q6, q6, q0
veor q7, q7, q1
vrev64.32 q6, q6
vrev64.32 q7, q7
// c += d;
vadd.u64 q4, q4, q6
vadd.u64 q5, q5, q7
// b = ror64(b ^ c, 24);
vld1.8 {M_0}, [ROR24_TABLE, :64]
veor q2, q2, q4
veor q3, q3, q5
vtbl.8 d4, {d4}, M_0
vtbl.8 d5, {d5}, M_0
vtbl.8 d6, {d6}, M_0
vtbl.8 d7, {d7}, M_0
// a += b + m[blake2b_sigma[r][2*i + 1]];
//
// M_0 got clobbered above, so we have to reload it if any of the four
// message words this step needs happens to be M_0. Otherwise we don't
// need to reload it here, as it will just get clobbered again below.
.if \s1 == 0 || \s3 == 0 || \s5 == 0 || \s7 == 0
vld1.8 {M_0}, [sp, :64]
.endif
vadd.u64 q0, q0, q2
vadd.u64 q1, q1, q3
vadd.u64 d0, d0, M_\s1
vadd.u64 d1, d1, M_\s3
vadd.u64 d2, d2, M_\s5
vadd.u64 d3, d3, M_\s7
// d = ror64(d ^ a, 16);
vld1.8 {M_0}, [ROR16_TABLE, :64]
veor q6, q6, q0
veor q7, q7, q1
vtbl.8 d12, {d12}, M_0
vtbl.8 d13, {d13}, M_0
vtbl.8 d14, {d14}, M_0
vtbl.8 d15, {d15}, M_0
// c += d;
vadd.u64 q4, q4, q6
vadd.u64 q5, q5, q7
// b = ror64(b ^ c, 63);
//
// This rotation amount isn't a multiple of 8, so it has to be
// implemented using a pair of shifts, which requires temporary
// registers. Use q8-q9 (M_0-M_3) for this, and reload them afterwards.
veor q8, q2, q4
veor q9, q3, q5
vshr.u64 q2, q8, #63
vshr.u64 q3, q9, #63
vsli.u64 q2, q8, #1
vsli.u64 q3, q9, #1
vld1.8 {q8-q9}, [sp, :256]
// Mix the diagonals:
// (v[0], v[5], v[10], v[15]), (v[1], v[6], v[11], v[12]),
// (v[2], v[7], v[8], v[13]), and (v[3], v[4], v[9], v[14]).
//
// There are two possible ways to do this: use 'vext' instructions to
// shift the rows of the matrix so that the diagonals become columns,
// and undo it afterwards; or just use 64-bit operations on 'd'
// registers instead of 128-bit operations on 'q' registers. We use the
// latter approach, as it performs much better on Cortex-A7.
// a += b + m[blake2b_sigma[r][2*i + 0]];
vadd.u64 d0, d0, d5
vadd.u64 d1, d1, d6
vadd.u64 d2, d2, d7
vadd.u64 d3, d3, d4
vadd.u64 d0, d0, M_\s8
vadd.u64 d1, d1, M_\s10
vadd.u64 d2, d2, M_\s12
vadd.u64 d3, d3, M_\s14
// d = ror64(d ^ a, 32);
veor d15, d15, d0
veor d12, d12, d1
veor d13, d13, d2
veor d14, d14, d3
vrev64.32 d15, d15
vrev64.32 d12, d12
vrev64.32 d13, d13
vrev64.32 d14, d14
// c += d;
vadd.u64 d10, d10, d15
vadd.u64 d11, d11, d12
vadd.u64 d8, d8, d13
vadd.u64 d9, d9, d14
// b = ror64(b ^ c, 24);
vld1.8 {M_0}, [ROR24_TABLE, :64]
veor d5, d5, d10
veor d6, d6, d11
veor d7, d7, d8
veor d4, d4, d9
vtbl.8 d5, {d5}, M_0
vtbl.8 d6, {d6}, M_0
vtbl.8 d7, {d7}, M_0
vtbl.8 d4, {d4}, M_0
// a += b + m[blake2b_sigma[r][2*i + 1]];
.if \s9 == 0 || \s11 == 0 || \s13 == 0 || \s15 == 0
vld1.8 {M_0}, [sp, :64]
.endif
vadd.u64 d0, d0, d5
vadd.u64 d1, d1, d6
vadd.u64 d2, d2, d7
vadd.u64 d3, d3, d4
vadd.u64 d0, d0, M_\s9
vadd.u64 d1, d1, M_\s11
vadd.u64 d2, d2, M_\s13
vadd.u64 d3, d3, M_\s15
// d = ror64(d ^ a, 16);
vld1.8 {M_0}, [ROR16_TABLE, :64]
veor d15, d15, d0
veor d12, d12, d1
veor d13, d13, d2
veor d14, d14, d3
vtbl.8 d12, {d12}, M_0
vtbl.8 d13, {d13}, M_0
vtbl.8 d14, {d14}, M_0
vtbl.8 d15, {d15}, M_0
// c += d;
vadd.u64 d10, d10, d15
vadd.u64 d11, d11, d12
vadd.u64 d8, d8, d13
vadd.u64 d9, d9, d14
// b = ror64(b ^ c, 63);
veor d16, d4, d9
veor d17, d5, d10
veor d18, d6, d11
veor d19, d7, d8
vshr.u64 q2, q8, #63
vshr.u64 q3, q9, #63
vsli.u64 q2, q8, #1
vsli.u64 q3, q9, #1
// Reloading q8-q9 can be skipped on the final round.
.if ! \final
vld1.8 {q8-q9}, [sp, :256]
.endif
.endm
//
// void blake2b_compress_neon(struct blake2b_state *state,
// const u8 *block, size_t nblocks, u32 inc);
//
// Only the first three fields of struct blake2b_state are used:
// u64 h[8]; (inout)
// u64 t[2]; (inout)
// u64 f[2]; (in)
//
.align 5
ENTRY(blake2b_compress_neon)
push {r4-r10}
// Allocate a 32-byte stack buffer that is 32-byte aligned.
mov ORIG_SP, sp
sub ip, sp, #32
bic ip, ip, #31
mov sp, ip
adr ROR24_TABLE, .Lror24_table
adr ROR16_TABLE, .Lror16_table
mov ip, STATE
vld1.64 {q0-q1}, [ip]! // Load h[0..3]
vld1.64 {q2-q3}, [ip]! // Load h[4..7]
.Lnext_block:
adr r10, .Lblake2b_IV
vld1.64 {q14-q15}, [ip] // Load t[0..1] and f[0..1]
vld1.64 {q4-q5}, [r10]! // Load IV[0..3]
vmov r7, r8, d28 // Copy t[0] to (r7, r8)
vld1.64 {q6-q7}, [r10] // Load IV[4..7]
adds r7, r7, INC // Increment counter
bcs .Lslow_inc_ctr
vmov.i32 d28[0], r7
vst1.64 {d28}, [ip] // Update t[0]
.Linc_ctr_done:
// Load the next message block and finish initializing the state matrix
// 'v'. Fortunately, there are exactly enough NEON registers to fit the
// entire state matrix in q0-q7 and the entire message block in q8-15.
//
// However, _blake2b_round also needs some extra registers for rotates,
// so we have to spill some registers. It's better to spill the message
// registers than the state registers, as the message doesn't change.
// Therefore we store a copy of the first 32 bytes of the message block
// (q8-q9) in an aligned buffer on the stack so that they can be
// reloaded when needed. (We could just reload directly from the
// message buffer, but it's faster to use aligned loads.)
vld1.8 {q8-q9}, [BLOCK]!
veor q6, q6, q14 // v[12..13] = IV[4..5] ^ t[0..1]
vld1.8 {q10-q11}, [BLOCK]!
veor q7, q7, q15 // v[14..15] = IV[6..7] ^ f[0..1]
vld1.8 {q12-q13}, [BLOCK]!
vst1.8 {q8-q9}, [sp, :256]
mov ip, STATE
vld1.8 {q14-q15}, [BLOCK]!
// Execute the rounds. Each round is provided the order in which it
// needs to use the message words.
_blake2b_round 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
_blake2b_round 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3
_blake2b_round 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4
_blake2b_round 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8
_blake2b_round 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13
_blake2b_round 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9
_blake2b_round 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11
_blake2b_round 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10
_blake2b_round 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5
_blake2b_round 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0
_blake2b_round 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
_blake2b_round 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 \
final=1
// Fold the final state matrix into the hash chaining value:
//
// for (i = 0; i < 8; i++)
// h[i] ^= v[i] ^ v[i + 8];
//
vld1.64 {q8-q9}, [ip]! // Load old h[0..3]
veor q0, q0, q4 // v[0..1] ^= v[8..9]
veor q1, q1, q5 // v[2..3] ^= v[10..11]
vld1.64 {q10-q11}, [ip] // Load old h[4..7]
veor q2, q2, q6 // v[4..5] ^= v[12..13]
veor q3, q3, q7 // v[6..7] ^= v[14..15]
veor q0, q0, q8 // v[0..1] ^= h[0..1]
veor q1, q1, q9 // v[2..3] ^= h[2..3]
mov ip, STATE
subs NBLOCKS, NBLOCKS, #1 // nblocks--
vst1.64 {q0-q1}, [ip]! // Store new h[0..3]
veor q2, q2, q10 // v[4..5] ^= h[4..5]
veor q3, q3, q11 // v[6..7] ^= h[6..7]
vst1.64 {q2-q3}, [ip]! // Store new h[4..7]
// Advance to the next block, if there is one.
bne .Lnext_block // nblocks != 0?
mov sp, ORIG_SP
pop {r4-r10}
mov pc, lr
.Lslow_inc_ctr:
// Handle the case where the counter overflowed its low 32 bits, by
// carrying the overflow bit into the full 128-bit counter.
vmov r9, r10, d29
adcs r8, r8, #0
adcs r9, r9, #0
adc r10, r10, #0
vmov d28, r7, r8
vmov d29, r9, r10
vst1.64 {q14}, [ip] // Update t[0] and t[1]
b .Linc_ctr_done
ENDPROC(blake2b_compress_neon)