arch/arm/crypto/poly1305-glue.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * OpenSSL/Cryptogams accelerated Poly1305 transform for ARM
   4  *
   5  * Copyright (C) 2019 Linaro Ltd. <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #include <asm/hwcap.h>
   9 #include <asm/neon.h>
  10 #include <asm/simd.h>
  11 #include <asm/unaligned.h>
  12 #include <crypto/algapi.h>
  13 #include <crypto/internal/hash.h>
  14 #include <crypto/internal/poly1305.h>
  15 #include <crypto/internal/simd.h>
  16 #include <linux/cpufeature.h>
  17 #include <linux/crypto.h>
  18 #include <linux/jump_label.h>
  19 #include <linux/module.h>
  20
  21 void poly1305_init_arm(void *state, const u8 *key);
  22 void poly1305_blocks_arm(void *state, const u8 *src, u32 len, u32 hibit);
  23 void poly1305_emit_arm(void *state, u8 *digest, const u32 *nonce);
  24
  25 void __weak poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit)
  26 {
  27 }
  28
  29 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
  30
  31 void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key)
  32 {
  33         poly1305_init_arm(&dctx->h, key);
  34         dctx->s[0] = get_unaligned_le32(key + 16);
  35         dctx->s[1] = get_unaligned_le32(key + 20);
  36         dctx->s[2] = get_unaligned_le32(key + 24);
  37         dctx->s[3] = get_unaligned_le32(key + 28);
  38         dctx->buflen = 0;
  39 }
  40 EXPORT_SYMBOL(poly1305_init_arch);
  41
  42 static int arm_poly1305_init(struct shash_desc *desc)
  43 {
  44         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
  45
  46         dctx->buflen = 0;
  47         dctx->rset = 0;
  48         dctx->sset = false;
  49
  50         return 0;
  51 }
  52
  53 static void arm_poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
  54                                  u32 len, u32 hibit, bool do_neon)
  55 {
  56         if (unlikely(!dctx->sset)) {
  57                 if (!dctx->rset) {
  58                         poly1305_init_arm(&dctx->h, src);
  59                         src += POLY1305_BLOCK_SIZE;
  60                         len -= POLY1305_BLOCK_SIZE;
  61                         dctx->rset = 1;
  62                 }
  63                 if (len >= POLY1305_BLOCK_SIZE) {
  64                         dctx->s[0] = get_unaligned_le32(src +  0);
  65                         dctx->s[1] = get_unaligned_le32(src +  4);
  66                         dctx->s[2] = get_unaligned_le32(src +  8);
  67                         dctx->s[3] = get_unaligned_le32(src + 12);
  68                         src += POLY1305_BLOCK_SIZE;
  69                         len -= POLY1305_BLOCK_SIZE;
  70                         dctx->sset = true;
  71                 }
  72                 if (len < POLY1305_BLOCK_SIZE)
  73                         return;
  74         }
  75
  76         len &= ~(POLY1305_BLOCK_SIZE - 1);
  77
  78         if (static_branch_likely(&have_neon) && likely(do_neon))
  79                 poly1305_blocks_neon(&dctx->h, src, len, hibit);
  80         else
  81                 poly1305_blocks_arm(&dctx->h, src, len, hibit);
  82 }
  83
  84 static void arm_poly1305_do_update(struct poly1305_desc_ctx *dctx,
  85                                     const u8 *src, u32 len, bool do_neon)
  86 {
  87         if (unlikely(dctx->buflen)) {
  88                 u32 bytes = min(len, POLY1305_BLOCK_SIZE - dctx->buflen);
  89
  90                 memcpy(dctx->buf + dctx->buflen, src, bytes);
  91                 src += bytes;
  92                 len -= bytes;
  93                 dctx->buflen += bytes;
  94
  95                 if (dctx->buflen == POLY1305_BLOCK_SIZE) {
  96                         arm_poly1305_blocks(dctx, dctx->buf,
  97                                             POLY1305_BLOCK_SIZE, 1, false);
  98                         dctx->buflen = 0;
  99                 }
 100         }
 101
 102         if (likely(len >= POLY1305_BLOCK_SIZE)) {
 103                 arm_poly1305_blocks(dctx, src, len, 1, do_neon);
 104                 src += round_down(len, POLY1305_BLOCK_SIZE);
 105                 len %= POLY1305_BLOCK_SIZE;
 106         }
 107
 108         if (unlikely(len)) {
 109                 dctx->buflen = len;
 110                 memcpy(dctx->buf, src, len);
 111         }
 112 }
 113
 114 static int arm_poly1305_update(struct shash_desc *desc,
 115                                const u8 *src, unsigned int srclen)
 116 {
 117         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 118
 119         arm_poly1305_do_update(dctx, src, srclen, false);
 120         return 0;
 121 }
 122
 123 static int __maybe_unused arm_poly1305_update_neon(struct shash_desc *desc,
 124                                                    const u8 *src,
 125                                                    unsigned int srclen)
 126 {
 127         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 128         bool do_neon = crypto_simd_usable() && srclen > 128;
 129
 130         if (static_branch_likely(&have_neon) && do_neon)
 131                 kernel_neon_begin();
 132         arm_poly1305_do_update(dctx, src, srclen, do_neon);
 133         if (static_branch_likely(&have_neon) && do_neon)
 134                 kernel_neon_end();
 135         return 0;
 136 }
 137
 138 void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src,
 139                           unsigned int nbytes)
 140 {
 141         bool do_neon = IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
 142                        crypto_simd_usable();
 143
 144         if (unlikely(dctx->buflen)) {
 145                 u32 bytes = min(nbytes, POLY1305_BLOCK_SIZE - dctx->buflen);
 146
 147                 memcpy(dctx->buf + dctx->buflen, src, bytes);
 148                 src += bytes;
 149                 nbytes -= bytes;
 150                 dctx->buflen += bytes;
 151
 152                 if (dctx->buflen == POLY1305_BLOCK_SIZE) {
 153                         poly1305_blocks_arm(&dctx->h, dctx->buf,
 154                                             POLY1305_BLOCK_SIZE, 1);
 155                         dctx->buflen = 0;
 156                 }
 157         }
 158
 159         if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
 160                 unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE);
 161
 162                 if (static_branch_likely(&have_neon) && do_neon) {
 163                         do {
 164                                 unsigned int todo = min_t(unsigned int, len, SZ_4K);
 165
 166                                 kernel_neon_begin();
 167                                 poly1305_blocks_neon(&dctx->h, src, todo, 1);
 168                                 kernel_neon_end();
 169
 170                                 len -= todo;
 171                                 src += todo;
 172                         } while (len);
 173                 } else {
 174                         poly1305_blocks_arm(&dctx->h, src, len, 1);
 175                         src += len;
 176                 }
 177                 nbytes %= POLY1305_BLOCK_SIZE;
 178         }
 179
 180         if (unlikely(nbytes)) {
 181                 dctx->buflen = nbytes;
 182                 memcpy(dctx->buf, src, nbytes);
 183         }
 184 }
 185 EXPORT_SYMBOL(poly1305_update_arch);
 186
 187 void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
 188 {
 189         if (unlikely(dctx->buflen)) {
 190                 dctx->buf[dctx->buflen++] = 1;
 191                 memset(dctx->buf + dctx->buflen, 0,
 192                        POLY1305_BLOCK_SIZE - dctx->buflen);
 193                 poly1305_blocks_arm(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
 194         }
 195
 196         poly1305_emit_arm(&dctx->h, dst, dctx->s);
 197         *dctx = (struct poly1305_desc_ctx){};
 198 }
 199 EXPORT_SYMBOL(poly1305_final_arch);
 200
 201 static int arm_poly1305_final(struct shash_desc *desc, u8 *dst)
 202 {
 203         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 204
 205         if (unlikely(!dctx->sset))
 206                 return -ENOKEY;
 207
 208         poly1305_final_arch(dctx, dst);
 209         return 0;
 210 }
 211
 212 static struct shash_alg arm_poly1305_algs[] = {{
 213         .init                   = arm_poly1305_init,
 214         .update                 = arm_poly1305_update,
 215         .final                  = arm_poly1305_final,
 216         .digestsize             = POLY1305_DIGEST_SIZE,
 217         .descsize               = sizeof(struct poly1305_desc_ctx),
 218
 219         .base.cra_name          = "poly1305",
 220         .base.cra_driver_name   = "poly1305-arm",
 221         .base.cra_priority      = 150,
 222         .base.cra_blocksize     = POLY1305_BLOCK_SIZE,
 223         .base.cra_module        = THIS_MODULE,
 224 #ifdef CONFIG_KERNEL_MODE_NEON
 225 }, {
 226         .init                   = arm_poly1305_init,
 227         .update                 = arm_poly1305_update_neon,
 228         .final                  = arm_poly1305_final,
 229         .digestsize             = POLY1305_DIGEST_SIZE,
 230         .descsize               = sizeof(struct poly1305_desc_ctx),
 231
 232         .base.cra_name          = "poly1305",
 233         .base.cra_driver_name   = "poly1305-neon",
 234         .base.cra_priority      = 200,
 235         .base.cra_blocksize     = POLY1305_BLOCK_SIZE,
 236         .base.cra_module        = THIS_MODULE,
 237 #endif
 238 }};
 239
 240 static int __init arm_poly1305_mod_init(void)
 241 {
 242         if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
 243             (elf_hwcap & HWCAP_NEON))
 244                 static_branch_enable(&have_neon);
 245         else if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
 246                 /* register only the first entry */
 247                 return crypto_register_shash(&arm_poly1305_algs[0]);
 248
 249         return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
 250                 crypto_register_shashes(arm_poly1305_algs,
 251                                         ARRAY_SIZE(arm_poly1305_algs)) : 0;
 252 }
 253
 254 static void __exit arm_poly1305_mod_exit(void)
 255 {
 256         if (!IS_REACHABLE(CONFIG_CRYPTO_HASH))
 257                 return;
 258         if (!static_branch_likely(&have_neon)) {
 259                 crypto_unregister_shash(&arm_poly1305_algs[0]);
 260                 return;
 261         }
 262         crypto_unregister_shashes(arm_poly1305_algs,
 263                                   ARRAY_SIZE(arm_poly1305_algs));
 264 }
 265
 266 module_init(arm_poly1305_mod_init);
 267 module_exit(arm_poly1305_mod_exit);
 268
 269 MODULE_LICENSE("GPL v2");
 270 MODULE_ALIAS_CRYPTO("poly1305");
 271 MODULE_ALIAS_CRYPTO("poly1305-arm");
 272 MODULE_ALIAS_CRYPTO("poly1305-neon");