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 <crypto/internal/poly1305.h>
9 #include <linux/cpufeature.h>
10 #include <linux/jump_label.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/unaligned.h>
14
15 asmlinkage void poly1305_p10le_4blocks(struct poly1305_block_state *state, const u8 *m, u32 mlen);
16 asmlinkage void poly1305_64s(struct poly1305_block_state *state, const u8 *m, u32 mlen, int highbit);
17 asmlinkage void poly1305_emit_64(const struct poly1305_state *state, const u32 nonce[4], u8 digest[POLY1305_DIGEST_SIZE]);
18
19 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_p10);
20
vsx_begin(void)21 static void vsx_begin(void)
22 {
23 preempt_disable();
24 enable_kernel_vsx();
25 }
26
vsx_end(void)27 static void vsx_end(void)
28 {
29 disable_kernel_vsx();
30 preempt_enable();
31 }
32
poly1305_block_init_arch(struct poly1305_block_state * dctx,const u8 raw_key[POLY1305_BLOCK_SIZE])33 void poly1305_block_init_arch(struct poly1305_block_state *dctx,
34 const u8 raw_key[POLY1305_BLOCK_SIZE])
35 {
36 if (!static_key_enabled(&have_p10))
37 return poly1305_block_init_generic(dctx, raw_key);
38
39 dctx->h = (struct poly1305_state){};
40 dctx->core_r.key.r64[0] = get_unaligned_le64(raw_key + 0);
41 dctx->core_r.key.r64[1] = get_unaligned_le64(raw_key + 8);
42 }
43 EXPORT_SYMBOL_GPL(poly1305_block_init_arch);
44
poly1305_blocks_arch(struct poly1305_block_state * state,const u8 * src,unsigned int len,u32 padbit)45 void poly1305_blocks_arch(struct poly1305_block_state *state, const u8 *src,
46 unsigned int len, u32 padbit)
47 {
48 if (!static_key_enabled(&have_p10))
49 return poly1305_blocks_generic(state, src, len, padbit);
50 vsx_begin();
51 if (len >= POLY1305_BLOCK_SIZE * 4) {
52 poly1305_p10le_4blocks(state, src, len);
53 src += len - (len % (POLY1305_BLOCK_SIZE * 4));
54 len %= POLY1305_BLOCK_SIZE * 4;
55 }
56 while (len >= POLY1305_BLOCK_SIZE) {
57 poly1305_64s(state, src, POLY1305_BLOCK_SIZE, padbit);
58 len -= POLY1305_BLOCK_SIZE;
59 src += POLY1305_BLOCK_SIZE;
60 }
61 vsx_end();
62 }
63 EXPORT_SYMBOL_GPL(poly1305_blocks_arch);
64
poly1305_emit_arch(const struct poly1305_state * state,u8 digest[POLY1305_DIGEST_SIZE],const u32 nonce[4])65 void poly1305_emit_arch(const struct poly1305_state *state,
66 u8 digest[POLY1305_DIGEST_SIZE],
67 const u32 nonce[4])
68 {
69 if (!static_key_enabled(&have_p10))
70 return poly1305_emit_generic(state, digest, nonce);
71 poly1305_emit_64(state, nonce, digest);
72 }
73 EXPORT_SYMBOL_GPL(poly1305_emit_arch);
74
poly1305_is_arch_optimized(void)75 bool poly1305_is_arch_optimized(void)
76 {
77 return static_key_enabled(&have_p10);
78 }
79 EXPORT_SYMBOL(poly1305_is_arch_optimized);
80
poly1305_p10_init(void)81 static int __init poly1305_p10_init(void)
82 {
83 if (cpu_has_feature(CPU_FTR_ARCH_31))
84 static_branch_enable(&have_p10);
85 return 0;
86 }
87 subsys_initcall(poly1305_p10_init);
88
poly1305_p10_exit(void)89 static void __exit poly1305_p10_exit(void)
90 {
91 }
92 module_exit(poly1305_p10_exit);
93
94 MODULE_LICENSE("GPL");
95 MODULE_AUTHOR("Danny Tsen <dtsen@linux.ibm.com>");
96 MODULE_DESCRIPTION("Optimized Poly1305 for P10");
97