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

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