tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Poly1305 authenticator algorithm, RFC7539.
4 *
5 * Copyright 2023- IBM Corp. All rights reserved.
6 */
7#include <asm/switch_to.h>
8#include <linux/cpufeature.h>
9#include <linux/jump_label.h>
10#include <linux/kernel.h>
11#include <linux/unaligned.h>
12
13asmlinkage void poly1305_p10le_4blocks(struct poly1305_block_state *state, const u8 *m, u32 mlen);
14asmlinkage void poly1305_64s(struct poly1305_block_state *state, const u8 *m, u32 mlen, int highbit);
15asmlinkage void poly1305_emit_64(const struct poly1305_state *state, const u32 nonce[4], u8 digest[POLY1305_DIGEST_SIZE]);
16
17static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_p10);
18
19static void vsx_begin(void)
20{
21 preempt_disable();
22 enable_kernel_vsx();
23}
24
25static void vsx_end(void)
26{
27 disable_kernel_vsx();
28 preempt_enable();
29}
30
31static void poly1305_block_init(struct poly1305_block_state *dctx,
32 const u8 raw_key[POLY1305_BLOCK_SIZE])
33{
34 if (!static_key_enabled(&have_p10))
35 return poly1305_block_init_generic(dctx, raw_key);
36
37 dctx->h = (struct poly1305_state){};
38 dctx->core_r.key.r64[0] = get_unaligned_le64(raw_key + 0);
39 dctx->core_r.key.r64[1] = get_unaligned_le64(raw_key + 8);
40}
41
42static void poly1305_blocks(struct poly1305_block_state *state, const u8 *src,
43 unsigned int len, u32 padbit)
44{
45 if (!static_key_enabled(&have_p10))
46 return poly1305_blocks_generic(state, src, len, padbit);
47 vsx_begin();
48 if (len >= POLY1305_BLOCK_SIZE * 4) {
49 poly1305_p10le_4blocks(state, src, len);
50 src += len - (len % (POLY1305_BLOCK_SIZE * 4));
51 len %= POLY1305_BLOCK_SIZE * 4;
52 }
53 while (len >= POLY1305_BLOCK_SIZE) {
54 poly1305_64s(state, src, POLY1305_BLOCK_SIZE, padbit);
55 len -= POLY1305_BLOCK_SIZE;
56 src += POLY1305_BLOCK_SIZE;
57 }
58 vsx_end();
59}
60
61static void poly1305_emit(const struct poly1305_state *state,
62 u8 digest[POLY1305_DIGEST_SIZE], const u32 nonce[4])
63{
64 if (!static_key_enabled(&have_p10))
65 return poly1305_emit_generic(state, digest, nonce);
66 poly1305_emit_64(state, nonce, digest);
67}
68
69#define poly1305_mod_init_arch poly1305_mod_init_arch
70static void poly1305_mod_init_arch(void)
71{
72 if (cpu_has_feature(CPU_FTR_ARCH_31))
73 static_branch_enable(&have_p10);
74}