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_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit);
  24 void poly1305_emit_arm(void *state, u8 *digest, const u32 *nonce);
  25
  26 void __weak poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit)
  27 {
  28 }
  29
  30 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
  31
  32 void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
  33 {
  34         poly1305_init_arm(&dctx->h, key);
  35         dctx->s[0] = get_unaligned_le32(key + 16);
  36         dctx->s[1] = get_unaligned_le32(key + 20);
  37         dctx->s[2] = get_unaligned_le32(key + 24);
  38         dctx->s[3] = get_unaligned_le32(key + 28);
  39         dctx->buflen = 0;
  40 }
  41 EXPORT_SYMBOL(poly1305_init_arch);
  42
  43 static int arm_poly1305_init(struct shash_desc *desc)
  44 {
  45         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
  46
  47         dctx->buflen = 0;
  48         dctx->rset = 0;
  49         dctx->sset = false;
  50
  51         return 0;
  52 }
  53
  54 static void arm_poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
  55                                  u32 len, u32 hibit, bool do_neon)
  56 {
  57         if (unlikely(!dctx->sset)) {
  58                 if (!dctx->rset) {
  59                         poly1305_init_arm(&dctx->h, src);
  60                         src += POLY1305_BLOCK_SIZE;
  61                         len -= POLY1305_BLOCK_SIZE;
  62                         dctx->rset = 1;
  63                 }
  64                 if (len >= POLY1305_BLOCK_SIZE) {
  65                         dctx->s[0] = get_unaligned_le32(src +  0);
  66                         dctx->s[1] = get_unaligned_le32(src +  4);
  67                         dctx->s[2] = get_unaligned_le32(src +  8);
  68                         dctx->s[3] = get_unaligned_le32(src + 12);
  69                         src += POLY1305_BLOCK_SIZE;
  70                         len -= POLY1305_BLOCK_SIZE;
  71                         dctx->sset = true;
  72                 }
  73                 if (len < POLY1305_BLOCK_SIZE)
  74                         return;
  75         }
  76
  77         len &= ~(POLY1305_BLOCK_SIZE - 1);
  78
  79         if (static_branch_likely(&have_neon) && likely(do_neon))
  80                 poly1305_blocks_neon(&dctx->h, src, len, hibit);
  81         else
  82                 poly1305_blocks_arm(&dctx->h, src, len, hibit);
  83 }
  84
  85 static void arm_poly1305_do_update(struct poly1305_desc_ctx *dctx,
  86                                     const u8 *src, u32 len, bool do_neon)
  87 {
  88         if (unlikely(dctx->buflen)) {
  89                 u32 bytes = min(len, POLY1305_BLOCK_SIZE - dctx->buflen);
  90
  91                 memcpy(dctx->buf + dctx->buflen, src, bytes);
  92                 src += bytes;
  93                 len -= bytes;
  94                 dctx->buflen += bytes;
  95
  96                 if (dctx->buflen == POLY1305_BLOCK_SIZE) {
  97                         arm_poly1305_blocks(dctx, dctx->buf,
  98                                             POLY1305_BLOCK_SIZE, 1, false);
  99                         dctx->buflen = 0;
 100                 }
 101         }
 102
 103         if (likely(len >= POLY1305_BLOCK_SIZE)) {
 104                 arm_poly1305_blocks(dctx, src, len, 1, do_neon);
 105                 src += round_down(len, POLY1305_BLOCK_SIZE);
 106                 len %= POLY1305_BLOCK_SIZE;
 107         }
 108
 109         if (unlikely(len)) {
 110                 dctx->buflen = len;
 111                 memcpy(dctx->buf, src, len);
 112         }
 113 }
 114
 115 static int arm_poly1305_update(struct shash_desc *desc,
 116                                const u8 *src, unsigned int srclen)
 117 {
 118         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 119
 120         arm_poly1305_do_update(dctx, src, srclen, false);
 121         return 0;
 122 }
 123
 124 static int __maybe_unused arm_poly1305_update_neon(struct shash_desc *desc,
 125                                                    const u8 *src,
 126                                                    unsigned int srclen)
 127 {
 128         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 129         bool do_neon = crypto_simd_usable() && srclen > 128;
 130
 131         if (static_branch_likely(&have_neon) && do_neon)
 132                 kernel_neon_begin();
 133         arm_poly1305_do_update(dctx, src, srclen, do_neon);
 134         if (static_branch_likely(&have_neon) && do_neon)
 135                 kernel_neon_end();
 136         return 0;
 137 }
 138
 139 void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src,
 140                           unsigned int nbytes)
 141 {
 142         bool do_neon = IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
 143                        crypto_simd_usable();
 144
 145         if (unlikely(dctx->buflen)) {
 146                 u32 bytes = min(nbytes, POLY1305_BLOCK_SIZE - dctx->buflen);
 147
 148                 memcpy(dctx->buf + dctx->buflen, src, bytes);
 149                 src += bytes;
 150                 nbytes -= bytes;
 151                 dctx->buflen += bytes;
 152
 153                 if (dctx->buflen == POLY1305_BLOCK_SIZE) {
 154                         poly1305_blocks_arm(&dctx->h, dctx->buf,
 155                                             POLY1305_BLOCK_SIZE, 1);
 156                         dctx->buflen = 0;
 157                 }
 158         }
 159
 160         if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
 161                 unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE);
 162
 163                 if (static_branch_likely(&have_neon) && do_neon) {
 164                         do {
 165                                 unsigned int todo = min_t(unsigned int, len, SZ_4K);
 166
 167                                 kernel_neon_begin();
 168                                 poly1305_blocks_neon(&dctx->h, src, todo, 1);
 169                                 kernel_neon_end();
 170
 171                                 len -= todo;
 172                                 src += todo;
 173                         } while (len);
 174                 } else {
 175                         poly1305_blocks_arm(&dctx->h, src, len, 1);
 176                         src += len;
 177                 }
 178                 nbytes %= POLY1305_BLOCK_SIZE;
 179         }
 180
 181         if (unlikely(nbytes)) {
 182                 dctx->buflen = nbytes;
 183                 memcpy(dctx->buf, src, nbytes);
 184         }
 185 }
 186 EXPORT_SYMBOL(poly1305_update_arch);
 187
 188 void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
 189 {
 190         if (unlikely(dctx->buflen)) {
 191                 dctx->buf[dctx->buflen++] = 1;
 192                 memset(dctx->buf + dctx->buflen, 0,
 193                        POLY1305_BLOCK_SIZE - dctx->buflen);
 194                 poly1305_blocks_arm(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
 195         }
 196
 197         poly1305_emit_arm(&dctx->h, dst, dctx->s);
 198         *dctx = (struct poly1305_desc_ctx){};
 199 }
 200 EXPORT_SYMBOL(poly1305_final_arch);
 201
 202 static int arm_poly1305_final(struct shash_desc *desc, u8 *dst)
 203 {
 204         struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 205
 206         if (unlikely(!dctx->sset))
 207                 return -ENOKEY;
 208
 209         poly1305_final_arch(dctx, dst);
 210         return 0;
 211 }
 212
 213 static struct shash_alg arm_poly1305_algs[] = {{
 214         .init                   = arm_poly1305_init,
 215         .update                 = arm_poly1305_update,
 216         .final                  = arm_poly1305_final,
 217         .digestsize             = POLY1305_DIGEST_SIZE,
 218         .descsize               = sizeof(struct poly1305_desc_ctx),
 219
 220         .base.cra_name          = "poly1305",
 221         .base.cra_driver_name   = "poly1305-arm",
 222         .base.cra_priority      = 150,
 223         .base.cra_blocksize     = POLY1305_BLOCK_SIZE,
 224         .base.cra_module        = THIS_MODULE,
 225 #ifdef CONFIG_KERNEL_MODE_NEON
 226 }, {
 227         .init                   = arm_poly1305_init,
 228         .update                 = arm_poly1305_update_neon,
 229         .final                  = arm_poly1305_final,
 230         .digestsize             = POLY1305_DIGEST_SIZE,
 231         .descsize               = sizeof(struct poly1305_desc_ctx),
 232
 233         .base.cra_name          = "poly1305",
 234         .base.cra_driver_name   = "poly1305-neon",
 235         .base.cra_priority      = 200,
 236         .base.cra_blocksize     = POLY1305_BLOCK_SIZE,
 237         .base.cra_module        = THIS_MODULE,
 238 #endif
 239 }};
 240
 241 static int __init arm_poly1305_mod_init(void)
 242 {
 243         if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
 244             (elf_hwcap & HWCAP_NEON))
 245                 static_branch_enable(&have_neon);
 246         else if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
 247                 /* register only the first entry */
 248                 return crypto_register_shash(&arm_poly1305_algs[0]);
 249
 250         return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
 251                 crypto_register_shashes(arm_poly1305_algs,
 252                                         ARRAY_SIZE(arm_poly1305_algs)) : 0;
 253 }
 254
 255 static void __exit arm_poly1305_mod_exit(void)
 256 {
 257         if (!IS_REACHABLE(CONFIG_CRYPTO_HASH))
 258                 return;
 259         if (!static_branch_likely(&have_neon)) {
 260                 crypto_unregister_shash(&arm_poly1305_algs[0]);
 261                 return;
 262         }
 263         crypto_unregister_shashes(arm_poly1305_algs,
 264                                   ARRAY_SIZE(arm_poly1305_algs));
 265 }
 266
 267 module_init(arm_poly1305_mod_init);
 268 module_exit(arm_poly1305_mod_exit);
 269
 270 MODULE_LICENSE("GPL v2");
 271 MODULE_ALIAS_CRYPTO("poly1305");
 272 MODULE_ALIAS_CRYPTO("poly1305-arm");
 273 MODULE_ALIAS_CRYPTO("poly1305-neon");