arch/arm/crypto/crc32-ce-glue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions
   4  *
   5  * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #include <linux/cpufeature.h>
   9 #include <linux/crc32.h>
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/string.h>
  14
  15 #include <crypto/internal/hash.h>
  16 #include <crypto/internal/simd.h>
  17
  18 #include <asm/hwcap.h>
  19 #include <asm/neon.h>
  20 #include <asm/simd.h>
  21 #include <asm/unaligned.h>
  22
  23 #define PMULL_MIN_LEN           64L     /* minimum size of buffer
  24                                          * for crc32_pmull_le_16 */
  25 #define SCALE_F                 16L     /* size of NEON register */
  26
  27 asmlinkage u32 crc32_pmull_le(const u8 buf[], u32 len, u32 init_crc);
  28 asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len);
  29
  30 asmlinkage u32 crc32c_pmull_le(const u8 buf[], u32 len, u32 init_crc);
  31 asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], u32 len);
  32
  33 static u32 (*fallback_crc32)(u32 init_crc, const u8 buf[], u32 len);
  34 static u32 (*fallback_crc32c)(u32 init_crc, const u8 buf[], u32 len);
  35
  36 static int crc32_cra_init(struct crypto_tfm *tfm)
  37 {
  38         u32 *key = crypto_tfm_ctx(tfm);
  39
  40         *key = 0;
  41         return 0;
  42 }
  43
  44 static int crc32c_cra_init(struct crypto_tfm *tfm)
  45 {
  46         u32 *key = crypto_tfm_ctx(tfm);
  47
  48         *key = ~0;
  49         return 0;
  50 }
  51
  52 static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
  53                         unsigned int keylen)
  54 {
  55         u32 *mctx = crypto_shash_ctx(hash);
  56
  57         if (keylen != sizeof(u32))
  58                 return -EINVAL;
  59         *mctx = le32_to_cpup((__le32 *)key);
  60         return 0;
  61 }
  62
  63 static int crc32_init(struct shash_desc *desc)
  64 {
  65         u32 *mctx = crypto_shash_ctx(desc->tfm);
  66         u32 *crc = shash_desc_ctx(desc);
  67
  68         *crc = *mctx;
  69         return 0;
  70 }
  71
  72 static int crc32_update(struct shash_desc *desc, const u8 *data,
  73                         unsigned int length)
  74 {
  75         u32 *crc = shash_desc_ctx(desc);
  76
  77         *crc = crc32_armv8_le(*crc, data, length);
  78         return 0;
  79 }
  80
  81 static int crc32c_update(struct shash_desc *desc, const u8 *data,
  82                          unsigned int length)
  83 {
  84         u32 *crc = shash_desc_ctx(desc);
  85
  86         *crc = crc32c_armv8_le(*crc, data, length);
  87         return 0;
  88 }
  89
  90 static int crc32_final(struct shash_desc *desc, u8 *out)
  91 {
  92         u32 *crc = shash_desc_ctx(desc);
  93
  94         put_unaligned_le32(*crc, out);
  95         return 0;
  96 }
  97
  98 static int crc32c_final(struct shash_desc *desc, u8 *out)
  99 {
 100         u32 *crc = shash_desc_ctx(desc);
 101
 102         put_unaligned_le32(~*crc, out);
 103         return 0;
 104 }
 105
 106 static int crc32_pmull_update(struct shash_desc *desc, const u8 *data,
 107                               unsigned int length)
 108 {
 109         u32 *crc = shash_desc_ctx(desc);
 110         unsigned int l;
 111
 112         if (crypto_simd_usable()) {
 113                 if ((u32)data % SCALE_F) {
 114                         l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F));
 115
 116                         *crc = fallback_crc32(*crc, data, l);
 117
 118                         data += l;
 119                         length -= l;
 120                 }
 121
 122                 if (length >= PMULL_MIN_LEN) {
 123                         l = round_down(length, SCALE_F);
 124
 125                         kernel_neon_begin();
 126                         *crc = crc32_pmull_le(data, l, *crc);
 127                         kernel_neon_end();
 128
 129                         data += l;
 130                         length -= l;
 131                 }
 132         }
 133
 134         if (length > 0)
 135                 *crc = fallback_crc32(*crc, data, length);
 136
 137         return 0;
 138 }
 139
 140 static int crc32c_pmull_update(struct shash_desc *desc, const u8 *data,
 141                                unsigned int length)
 142 {
 143         u32 *crc = shash_desc_ctx(desc);
 144         unsigned int l;
 145
 146         if (crypto_simd_usable()) {
 147                 if ((u32)data % SCALE_F) {
 148                         l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F));
 149
 150                         *crc = fallback_crc32c(*crc, data, l);
 151
 152                         data += l;
 153                         length -= l;
 154                 }
 155
 156                 if (length >= PMULL_MIN_LEN) {
 157                         l = round_down(length, SCALE_F);
 158
 159                         kernel_neon_begin();
 160                         *crc = crc32c_pmull_le(data, l, *crc);
 161                         kernel_neon_end();
 162
 163                         data += l;
 164                         length -= l;
 165                 }
 166         }
 167
 168         if (length > 0)
 169                 *crc = fallback_crc32c(*crc, data, length);
 170
 171         return 0;
 172 }
 173
 174 static struct shash_alg crc32_pmull_algs[] = { {
 175         .setkey                 = crc32_setkey,
 176         .init                   = crc32_init,
 177         .update                 = crc32_update,
 178         .final                  = crc32_final,
 179         .descsize               = sizeof(u32),
 180         .digestsize             = sizeof(u32),
 181
 182         .base.cra_ctxsize       = sizeof(u32),
 183         .base.cra_init          = crc32_cra_init,
 184         .base.cra_name          = "crc32",
 185         .base.cra_driver_name   = "crc32-arm-ce",
 186         .base.cra_priority      = 200,
 187         .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
 188         .base.cra_blocksize     = 1,
 189         .base.cra_module        = THIS_MODULE,
 190 }, {
 191         .setkey                 = crc32_setkey,
 192         .init                   = crc32_init,
 193         .update                 = crc32c_update,
 194         .final                  = crc32c_final,
 195         .descsize               = sizeof(u32),
 196         .digestsize             = sizeof(u32),
 197
 198         .base.cra_ctxsize       = sizeof(u32),
 199         .base.cra_init          = crc32c_cra_init,
 200         .base.cra_name          = "crc32c",
 201         .base.cra_driver_name   = "crc32c-arm-ce",
 202         .base.cra_priority      = 200,
 203         .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
 204         .base.cra_blocksize     = 1,
 205         .base.cra_module        = THIS_MODULE,
 206 } };
 207
 208 static int __init crc32_pmull_mod_init(void)
 209 {
 210         if (elf_hwcap2 & HWCAP2_PMULL) {
 211                 crc32_pmull_algs[0].update = crc32_pmull_update;
 212                 crc32_pmull_algs[1].update = crc32c_pmull_update;
 213
 214                 if (elf_hwcap2 & HWCAP2_CRC32) {
 215                         fallback_crc32 = crc32_armv8_le;
 216                         fallback_crc32c = crc32c_armv8_le;
 217                 } else {
 218                         fallback_crc32 = crc32_le;
 219                         fallback_crc32c = __crc32c_le;
 220                 }
 221         } else if (!(elf_hwcap2 & HWCAP2_CRC32)) {
 222                 return -ENODEV;
 223         }
 224
 225         return crypto_register_shashes(crc32_pmull_algs,
 226                                        ARRAY_SIZE(crc32_pmull_algs));
 227 }
 228
 229 static void __exit crc32_pmull_mod_exit(void)
 230 {
 231         crypto_unregister_shashes(crc32_pmull_algs,
 232                                   ARRAY_SIZE(crc32_pmull_algs));
 233 }
 234
 235 static const struct cpu_feature __maybe_unused crc32_cpu_feature[] = {
 236         { cpu_feature(CRC32) }, { cpu_feature(PMULL) }, { }
 237 };
 238 MODULE_DEVICE_TABLE(cpu, crc32_cpu_feature);
 239
 240 module_init(crc32_pmull_mod_init);
 241 module_exit(crc32_pmull_mod_exit);
 242
 243 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 244 MODULE_LICENSE("GPL v2");
 245 MODULE_ALIAS_CRYPTO("crc32");
 246 MODULE_ALIAS_CRYPTO("crc32c");