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Merge tag 'io_uring-5.7-2020-05-22' of git://git.kernel.dk/linux-block
[thirdparty/linux.git] / arch / x86 / crypto / poly1305_glue.c
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d7d7b853 1// SPDX-License-Identifier: GPL-2.0 OR MIT
c70f4abe 2/*
d7d7b853 3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
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4 */
5
6#include <crypto/algapi.h>
7#include <crypto/internal/hash.h>
48ea8c6e 8#include <crypto/internal/poly1305.h>
f2abe0d7 9#include <crypto/internal/simd.h>
c70f4abe 10#include <linux/crypto.h>
f0e89bcf 11#include <linux/jump_label.h>
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12#include <linux/kernel.h>
13#include <linux/module.h>
d7d7b853 14#include <asm/intel-family.h>
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15#include <asm/simd.h>
16
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17asmlinkage void poly1305_init_x86_64(void *ctx,
18 const u8 key[POLY1305_KEY_SIZE]);
19asmlinkage void poly1305_blocks_x86_64(void *ctx, const u8 *inp,
20 const size_t len, const u32 padbit);
21asmlinkage void poly1305_emit_x86_64(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
22 const u32 nonce[4]);
23asmlinkage void poly1305_emit_avx(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
24 const u32 nonce[4]);
25asmlinkage void poly1305_blocks_avx(void *ctx, const u8 *inp, const size_t len,
26 const u32 padbit);
27asmlinkage void poly1305_blocks_avx2(void *ctx, const u8 *inp, const size_t len,
28 const u32 padbit);
29asmlinkage void poly1305_blocks_avx512(void *ctx, const u8 *inp,
30 const size_t len, const u32 padbit);
31
32static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx);
f0e89bcf 33static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx2);
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34static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx512);
35
36struct poly1305_arch_internal {
37 union {
38 struct {
39 u32 h[5];
40 u32 is_base2_26;
41 };
42 u64 hs[3];
43 };
44 u64 r[2];
45 u64 pad;
46 struct { u32 r2, r1, r4, r3; } rn[9];
47};
da35b22d 48
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49/* The AVX code uses base 2^26, while the scalar code uses base 2^64. If we hit
50 * the unfortunate situation of using AVX and then having to go back to scalar
51 * -- because the user is silly and has called the update function from two
52 * separate contexts -- then we need to convert back to the original base before
53 * proceeding. It is possible to reason that the initial reduction below is
54 * sufficient given the implementation invariants. However, for an avoidance of
55 * doubt and because this is not performance critical, we do the full reduction
56 * anyway. Z3 proof of below function: https://xn--4db.cc/ltPtHCKN/py
57 */
58static void convert_to_base2_64(void *ctx)
1c08a104 59{
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60 struct poly1305_arch_internal *state = ctx;
61 u32 cy;
1c08a104 62
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63 if (!state->is_base2_26)
64 return;
1c08a104 65
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66 cy = state->h[0] >> 26; state->h[0] &= 0x3ffffff; state->h[1] += cy;
67 cy = state->h[1] >> 26; state->h[1] &= 0x3ffffff; state->h[2] += cy;
68 cy = state->h[2] >> 26; state->h[2] &= 0x3ffffff; state->h[3] += cy;
69 cy = state->h[3] >> 26; state->h[3] &= 0x3ffffff; state->h[4] += cy;
70 state->hs[0] = ((u64)state->h[2] << 52) | ((u64)state->h[1] << 26) | state->h[0];
71 state->hs[1] = ((u64)state->h[4] << 40) | ((u64)state->h[3] << 14) | (state->h[2] >> 12);
72 state->hs[2] = state->h[4] >> 24;
73#define ULT(a, b) ((a ^ ((a ^ b) | ((a - b) ^ b))) >> (sizeof(a) * 8 - 1))
74 cy = (state->hs[2] >> 2) + (state->hs[2] & ~3ULL);
75 state->hs[2] &= 3;
76 state->hs[0] += cy;
77 state->hs[1] += (cy = ULT(state->hs[0], cy));
78 state->hs[2] += ULT(state->hs[1], cy);
79#undef ULT
80 state->is_base2_26 = 0;
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81}
82
d7d7b853 83static void poly1305_simd_init(void *ctx, const u8 key[POLY1305_KEY_SIZE])
da35b22d 84{
d7d7b853 85 poly1305_init_x86_64(ctx, key);
da35b22d 86}
c70f4abe 87
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88static void poly1305_simd_blocks(void *ctx, const u8 *inp, size_t len,
89 const u32 padbit)
1c08a104 90{
d7d7b853 91 struct poly1305_arch_internal *state = ctx;
1c08a104 92
d7d7b853 93 /* SIMD disables preemption, so relax after processing each page. */
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94 BUILD_BUG_ON(SZ_4K < POLY1305_BLOCK_SIZE ||
95 SZ_4K % POLY1305_BLOCK_SIZE);
1c08a104 96
42251572 97 if (!static_branch_likely(&poly1305_use_avx) ||
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98 (len < (POLY1305_BLOCK_SIZE * 18) && !state->is_base2_26) ||
99 !crypto_simd_usable()) {
100 convert_to_base2_64(ctx);
101 poly1305_blocks_x86_64(ctx, inp, len, padbit);
1c08a104 102 return;
d7d7b853 103 }
1c08a104 104
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105 do {
106 const size_t bytes = min_t(size_t, len, SZ_4K);
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107
108 kernel_fpu_begin();
109 if (IS_ENABLED(CONFIG_AS_AVX512) && static_branch_likely(&poly1305_use_avx512))
110 poly1305_blocks_avx512(ctx, inp, bytes, padbit);
e6abef61 111 else if (static_branch_likely(&poly1305_use_avx2))
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112 poly1305_blocks_avx2(ctx, inp, bytes, padbit);
113 else
114 poly1305_blocks_avx(ctx, inp, bytes, padbit);
115 kernel_fpu_end();
706024a5 116
d7d7b853 117 len -= bytes;
d7d7b853 118 inp += bytes;
706024a5 119 } while (len);
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120}
121
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122static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
123 const u32 nonce[4])
1c08a104 124{
42251572 125 if (!static_branch_likely(&poly1305_use_avx))
d7d7b853 126 poly1305_emit_x86_64(ctx, mac, nonce);
f9e7fe32 127 else
d7d7b853 128 poly1305_emit_avx(ctx, mac, nonce);
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129}
130
d7d7b853 131void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
1c08a104 132{
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133 poly1305_simd_init(&dctx->h, key);
134 dctx->s[0] = get_unaligned_le32(&key[16]);
135 dctx->s[1] = get_unaligned_le32(&key[20]);
136 dctx->s[2] = get_unaligned_le32(&key[24]);
137 dctx->s[3] = get_unaligned_le32(&key[28]);
138 dctx->buflen = 0;
139 dctx->sset = true;
1c08a104 140}
d7d7b853 141EXPORT_SYMBOL(poly1305_init_arch);
1c08a104 142
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143static unsigned int crypto_poly1305_setdctxkey(struct poly1305_desc_ctx *dctx,
144 const u8 *inp, unsigned int len)
1c08a104 145{
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146 unsigned int acc = 0;
147 if (unlikely(!dctx->sset)) {
148 if (!dctx->rset && len >= POLY1305_BLOCK_SIZE) {
149 poly1305_simd_init(&dctx->h, inp);
150 inp += POLY1305_BLOCK_SIZE;
151 len -= POLY1305_BLOCK_SIZE;
152 acc += POLY1305_BLOCK_SIZE;
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153 dctx->rset = 1;
154 }
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155 if (len >= POLY1305_BLOCK_SIZE) {
156 dctx->s[0] = get_unaligned_le32(&inp[0]);
157 dctx->s[1] = get_unaligned_le32(&inp[4]);
158 dctx->s[2] = get_unaligned_le32(&inp[8]);
159 dctx->s[3] = get_unaligned_le32(&inp[12]);
160 inp += POLY1305_BLOCK_SIZE;
161 len -= POLY1305_BLOCK_SIZE;
162 acc += POLY1305_BLOCK_SIZE;
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163 dctx->sset = true;
164 }
165 }
d7d7b853 166 return acc;
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167}
168
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169void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src,
170 unsigned int srclen)
c70f4abe 171{
d7d7b853 172 unsigned int bytes, used;
c70f4abe 173
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174 if (unlikely(dctx->buflen)) {
175 bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
176 memcpy(dctx->buf + dctx->buflen, src, bytes);
177 src += bytes;
178 srclen -= bytes;
179 dctx->buflen += bytes;
180
181 if (dctx->buflen == POLY1305_BLOCK_SIZE) {
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182 if (likely(!crypto_poly1305_setdctxkey(dctx, dctx->buf, POLY1305_BLOCK_SIZE)))
183 poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 1);
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184 dctx->buflen = 0;
185 }
186 }
187
188 if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
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189 bytes = round_down(srclen, POLY1305_BLOCK_SIZE);
190 srclen -= bytes;
191 used = crypto_poly1305_setdctxkey(dctx, src, bytes);
192 if (likely(bytes - used))
193 poly1305_simd_blocks(&dctx->h, src + used, bytes - used, 1);
194 src += bytes;
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195 }
196
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197 if (unlikely(srclen)) {
198 dctx->buflen = srclen;
199 memcpy(dctx->buf, src, srclen);
200 }
1b2c6a51 201}
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202EXPORT_SYMBOL(poly1305_update_arch);
203
d7d7b853 204void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
f0e89bcf 205{
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206 if (unlikely(dctx->buflen)) {
207 dctx->buf[dctx->buflen++] = 1;
208 memset(dctx->buf + dctx->buflen, 0,
209 POLY1305_BLOCK_SIZE - dctx->buflen);
210 poly1305_simd_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
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211 }
212
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213 poly1305_simd_emit(&dctx->h, dst, dctx->s);
214 *dctx = (struct poly1305_desc_ctx){};
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215}
216EXPORT_SYMBOL(poly1305_final_arch);
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217
218static int crypto_poly1305_init(struct shash_desc *desc)
219{
220 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
221
d7d7b853 222 *dctx = (struct poly1305_desc_ctx){};
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223 return 0;
224}
225
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226static int crypto_poly1305_update(struct shash_desc *desc,
227 const u8 *src, unsigned int srclen)
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228{
229 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
230
d7d7b853 231 poly1305_update_arch(dctx, src, srclen);
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232 return 0;
233}
234
d7d7b853 235static int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
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236{
237 struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
238
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239 if (unlikely(!dctx->sset))
240 return -ENOKEY;
241
242 poly1305_final_arch(dctx, dst);
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243 return 0;
244}
245
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246static struct shash_alg alg = {
247 .digestsize = POLY1305_DIGEST_SIZE,
ad8f5b88 248 .init = crypto_poly1305_init,
d7d7b853 249 .update = crypto_poly1305_update,
c70f4abe 250 .final = crypto_poly1305_final,
ad8f5b88 251 .descsize = sizeof(struct poly1305_desc_ctx),
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252 .base = {
253 .cra_name = "poly1305",
254 .cra_driver_name = "poly1305-simd",
255 .cra_priority = 300,
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256 .cra_blocksize = POLY1305_BLOCK_SIZE,
257 .cra_module = THIS_MODULE,
258 },
259};
260
261static int __init poly1305_simd_mod_init(void)
262{
42251572 263 if (boot_cpu_has(X86_FEATURE_AVX) &&
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264 cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
265 static_branch_enable(&poly1305_use_avx);
e6abef61 266 if (boot_cpu_has(X86_FEATURE_AVX) && boot_cpu_has(X86_FEATURE_AVX2) &&
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267 cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
268 static_branch_enable(&poly1305_use_avx2);
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269 if (IS_ENABLED(CONFIG_AS_AVX512) && boot_cpu_has(X86_FEATURE_AVX) &&
270 boot_cpu_has(X86_FEATURE_AVX2) && boot_cpu_has(X86_FEATURE_AVX512F) &&
271 cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM | XFEATURE_MASK_AVX512, NULL) &&
272 /* Skylake downclocks unacceptably much when using zmm, but later generations are fast. */
273 boot_cpu_data.x86_model != INTEL_FAM6_SKYLAKE_X)
274 static_branch_enable(&poly1305_use_avx512);
8394bfec 275 return IS_REACHABLE(CONFIG_CRYPTO_HASH) ? crypto_register_shash(&alg) : 0;
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276}
277
278static void __exit poly1305_simd_mod_exit(void)
279{
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280 if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
281 crypto_unregister_shash(&alg);
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282}
283
284module_init(poly1305_simd_mod_init);
285module_exit(poly1305_simd_mod_exit);
286
287MODULE_LICENSE("GPL");
d7d7b853 288MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
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289MODULE_DESCRIPTION("Poly1305 authenticator");
290MODULE_ALIAS_CRYPTO("poly1305");
291MODULE_ALIAS_CRYPTO("poly1305-simd");