arch/arm/crypto/ghash-ce-glue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
   4  *
   5  * Copyright (C) 2015 - 2018 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/b128ops.h>
  13 #include <crypto/cryptd.h>
  14 #include <crypto/internal/hash.h>
  15 #include <crypto/internal/simd.h>
  16 #include <crypto/gf128mul.h>
  17 #include <linux/cpufeature.h>
  18 #include <linux/crypto.h>
  19 #include <linux/jump_label.h>
  20 #include <linux/module.h>
  21
  22 MODULE_DESCRIPTION("GHASH hash function using ARMv8 Crypto Extensions");
  23 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  24 MODULE_LICENSE("GPL v2");
  25 MODULE_ALIAS_CRYPTO("ghash");
  26
  27 #define GHASH_BLOCK_SIZE        16
  28 #define GHASH_DIGEST_SIZE       16
  29
  30 struct ghash_key {
  31         be128   k;
  32         u64     h[][2];
  33 };
  34
  35 struct ghash_desc_ctx {
  36         u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
  37         u8 buf[GHASH_BLOCK_SIZE];
  38         u32 count;
  39 };
  40
  41 struct ghash_async_ctx {
  42         struct cryptd_ahash *cryptd_tfm;
  43 };
  44
  45 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src,
  46                                        u64 const h[][2], const char *head);
  47
  48 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src,
  49                                       u64 const h[][2], const char *head);
  50
  51 static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_p64);
  52
  53 static int ghash_init(struct shash_desc *desc)
  54 {
  55         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  56
  57         *ctx = (struct ghash_desc_ctx){};
  58         return 0;
  59 }
  60
  61 static void ghash_do_update(int blocks, u64 dg[], const char *src,
  62                             struct ghash_key *key, const char *head)
  63 {
  64         if (likely(crypto_simd_usable())) {
  65                 kernel_neon_begin();
  66                 if (static_branch_likely(&use_p64))
  67                         pmull_ghash_update_p64(blocks, dg, src, key->h, head);
  68                 else
  69                         pmull_ghash_update_p8(blocks, dg, src, key->h, head);
  70                 kernel_neon_end();
  71         } else {
  72                 be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) };
  73
  74                 do {
  75                         const u8 *in = src;
  76
  77                         if (head) {
  78                                 in = head;
  79                                 blocks++;
  80                                 head = NULL;
  81                         } else {
  82                                 src += GHASH_BLOCK_SIZE;
  83                         }
  84
  85                         crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE);
  86                         gf128mul_lle(&dst, &key->k);
  87                 } while (--blocks);
  88
  89                 dg[0] = be64_to_cpu(dst.b);
  90                 dg[1] = be64_to_cpu(dst.a);
  91         }
  92 }
  93
  94 static int ghash_update(struct shash_desc *desc, const u8 *src,
  95                         unsigned int len)
  96 {
  97         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  98         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  99
 100         ctx->count += len;
 101
 102         if ((partial + len) >= GHASH_BLOCK_SIZE) {
 103                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
 104                 int blocks;
 105
 106                 if (partial) {
 107                         int p = GHASH_BLOCK_SIZE - partial;
 108
 109                         memcpy(ctx->buf + partial, src, p);
 110                         src += p;
 111                         len -= p;
 112                 }
 113
 114                 blocks = len / GHASH_BLOCK_SIZE;
 115                 len %= GHASH_BLOCK_SIZE;
 116
 117                 ghash_do_update(blocks, ctx->digest, src, key,
 118                                 partial ? ctx->buf : NULL);
 119                 src += blocks * GHASH_BLOCK_SIZE;
 120                 partial = 0;
 121         }
 122         if (len)
 123                 memcpy(ctx->buf + partial, src, len);
 124         return 0;
 125 }
 126
 127 static int ghash_final(struct shash_desc *desc, u8 *dst)
 128 {
 129         struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
 130         unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
 131
 132         if (partial) {
 133                 struct ghash_key *key = crypto_shash_ctx(desc->tfm);
 134
 135                 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
 136                 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL);
 137         }
 138         put_unaligned_be64(ctx->digest[1], dst);
 139         put_unaligned_be64(ctx->digest[0], dst + 8);
 140
 141         *ctx = (struct ghash_desc_ctx){};
 142         return 0;
 143 }
 144
 145 static void ghash_reflect(u64 h[], const be128 *k)
 146 {
 147         u64 carry = be64_to_cpu(k->a) >> 63;
 148
 149         h[0] = (be64_to_cpu(k->b) << 1) | carry;
 150         h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
 151
 152         if (carry)
 153                 h[1] ^= 0xc200000000000000UL;
 154 }
 155
 156 static int ghash_setkey(struct crypto_shash *tfm,
 157                         const u8 *inkey, unsigned int keylen)
 158 {
 159         struct ghash_key *key = crypto_shash_ctx(tfm);
 160
 161         if (keylen != GHASH_BLOCK_SIZE)
 162                 return -EINVAL;
 163
 164         /* needed for the fallback */
 165         memcpy(&key->k, inkey, GHASH_BLOCK_SIZE);
 166         ghash_reflect(key->h[0], &key->k);
 167
 168         if (static_branch_likely(&use_p64)) {
 169                 be128 h = key->k;
 170
 171                 gf128mul_lle(&h, &key->k);
 172                 ghash_reflect(key->h[1], &h);
 173
 174                 gf128mul_lle(&h, &key->k);
 175                 ghash_reflect(key->h[2], &h);
 176
 177                 gf128mul_lle(&h, &key->k);
 178                 ghash_reflect(key->h[3], &h);
 179         }
 180         return 0;
 181 }
 182
 183 static struct shash_alg ghash_alg = {
 184         .digestsize             = GHASH_DIGEST_SIZE,
 185         .init                   = ghash_init,
 186         .update                 = ghash_update,
 187         .final                  = ghash_final,
 188         .setkey                 = ghash_setkey,
 189         .descsize               = sizeof(struct ghash_desc_ctx),
 190
 191         .base.cra_name          = "ghash",
 192         .base.cra_driver_name   = "ghash-ce-sync",
 193         .base.cra_priority      = 300 - 1,
 194         .base.cra_blocksize     = GHASH_BLOCK_SIZE,
 195         .base.cra_ctxsize       = sizeof(struct ghash_key) + sizeof(u64[2]),
 196         .base.cra_module        = THIS_MODULE,
 197 };
 198
 199 static int ghash_async_init(struct ahash_request *req)
 200 {
 201         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 202         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 203         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 204         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 205         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 206         struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 207
 208         desc->tfm = child;
 209         return crypto_shash_init(desc);
 210 }
 211
 212 static int ghash_async_update(struct ahash_request *req)
 213 {
 214         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 215         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 216         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 217         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 218
 219         if (!crypto_simd_usable() ||
 220             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 221                 memcpy(cryptd_req, req, sizeof(*req));
 222                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 223                 return crypto_ahash_update(cryptd_req);
 224         } else {
 225                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 226                 return shash_ahash_update(req, desc);
 227         }
 228 }
 229
 230 static int ghash_async_final(struct ahash_request *req)
 231 {
 232         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 233         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 234         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 235         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 236
 237         if (!crypto_simd_usable() ||
 238             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 239                 memcpy(cryptd_req, req, sizeof(*req));
 240                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 241                 return crypto_ahash_final(cryptd_req);
 242         } else {
 243                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 244                 return crypto_shash_final(desc, req->result);
 245         }
 246 }
 247
 248 static int ghash_async_digest(struct ahash_request *req)
 249 {
 250         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 251         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 252         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 253         struct cryptd_ahash *cryptd_tfm = ctx->cryptd_tfm;
 254
 255         if (!crypto_simd_usable() ||
 256             (in_atomic() && cryptd_ahash_queued(cryptd_tfm))) {
 257                 memcpy(cryptd_req, req, sizeof(*req));
 258                 ahash_request_set_tfm(cryptd_req, &cryptd_tfm->base);
 259                 return crypto_ahash_digest(cryptd_req);
 260         } else {
 261                 struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 262                 struct crypto_shash *child = cryptd_ahash_child(cryptd_tfm);
 263
 264                 desc->tfm = child;
 265                 return shash_ahash_digest(req, desc);
 266         }
 267 }
 268
 269 static int ghash_async_import(struct ahash_request *req, const void *in)
 270 {
 271         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 272         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 273         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 274         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 275
 276         desc->tfm = cryptd_ahash_child(ctx->cryptd_tfm);
 277
 278         return crypto_shash_import(desc, in);
 279 }
 280
 281 static int ghash_async_export(struct ahash_request *req, void *out)
 282 {
 283         struct ahash_request *cryptd_req = ahash_request_ctx(req);
 284         struct shash_desc *desc = cryptd_shash_desc(cryptd_req);
 285
 286         return crypto_shash_export(desc, out);
 287 }
 288
 289 static int ghash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
 290                               unsigned int keylen)
 291 {
 292         struct ghash_async_ctx *ctx = crypto_ahash_ctx(tfm);
 293         struct crypto_ahash *child = &ctx->cryptd_tfm->base;
 294
 295         crypto_ahash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 296         crypto_ahash_set_flags(child, crypto_ahash_get_flags(tfm)
 297                                & CRYPTO_TFM_REQ_MASK);
 298         return crypto_ahash_setkey(child, key, keylen);
 299 }
 300
 301 static int ghash_async_init_tfm(struct crypto_tfm *tfm)
 302 {
 303         struct cryptd_ahash *cryptd_tfm;
 304         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 305
 306         cryptd_tfm = cryptd_alloc_ahash("ghash-ce-sync", 0, 0);
 307         if (IS_ERR(cryptd_tfm))
 308                 return PTR_ERR(cryptd_tfm);
 309         ctx->cryptd_tfm = cryptd_tfm;
 310         crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
 311                                  sizeof(struct ahash_request) +
 312                                  crypto_ahash_reqsize(&cryptd_tfm->base));
 313
 314         return 0;
 315 }
 316
 317 static void ghash_async_exit_tfm(struct crypto_tfm *tfm)
 318 {
 319         struct ghash_async_ctx *ctx = crypto_tfm_ctx(tfm);
 320
 321         cryptd_free_ahash(ctx->cryptd_tfm);
 322 }
 323
 324 static struct ahash_alg ghash_async_alg = {
 325         .init                   = ghash_async_init,
 326         .update                 = ghash_async_update,
 327         .final                  = ghash_async_final,
 328         .setkey                 = ghash_async_setkey,
 329         .digest                 = ghash_async_digest,
 330         .import                 = ghash_async_import,
 331         .export                 = ghash_async_export,
 332         .halg.digestsize        = GHASH_DIGEST_SIZE,
 333         .halg.statesize         = sizeof(struct ghash_desc_ctx),
 334         .halg.base              = {
 335                 .cra_name       = "ghash",
 336                 .cra_driver_name = "ghash-ce",
 337                 .cra_priority   = 300,
 338                 .cra_flags      = CRYPTO_ALG_ASYNC,
 339                 .cra_blocksize  = GHASH_BLOCK_SIZE,
 340                 .cra_ctxsize    = sizeof(struct ghash_async_ctx),
 341                 .cra_module     = THIS_MODULE,
 342                 .cra_init       = ghash_async_init_tfm,
 343                 .cra_exit       = ghash_async_exit_tfm,
 344         },
 345 };
 346
 347 static int __init ghash_ce_mod_init(void)
 348 {
 349         int err;
 350
 351         if (!(elf_hwcap & HWCAP_NEON))
 352                 return -ENODEV;
 353
 354         if (elf_hwcap2 & HWCAP2_PMULL) {
 355                 ghash_alg.base.cra_ctxsize += 3 * sizeof(u64[2]);
 356                 static_branch_enable(&use_p64);
 357         }
 358
 359         err = crypto_register_shash(&ghash_alg);
 360         if (err)
 361                 return err;
 362         err = crypto_register_ahash(&ghash_async_alg);
 363         if (err)
 364                 goto err_shash;
 365
 366         return 0;
 367
 368 err_shash:
 369         crypto_unregister_shash(&ghash_alg);
 370         return err;
 371 }
 372
 373 static void __exit ghash_ce_mod_exit(void)
 374 {
 375         crypto_unregister_ahash(&ghash_async_alg);
 376         crypto_unregister_shash(&ghash_alg);
 377 }
 378
 379 module_init(ghash_ce_mod_init);
 380 module_exit(ghash_ce_mod_exit);