arch/arm64/crypto/crc32-ce-glue.c

   1 /*
   2  * Accelerated CRC32(C) using arm64 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/cpufeature.h>
  12 #include <linux/crc32.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/string.h>
  17
  18 #include <crypto/internal/hash.h>
  19
  20 #include <asm/hwcap.h>
  21 #include <asm/neon.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[], u64 len, u32 init_crc);
  29 asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], size_t len);
  30
  31 asmlinkage u32 crc32c_pmull_le(const u8 buf[], u64 len, u32 init_crc);
  32 asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], size_t len);
  33
  34 static u32 (*fallback_crc32)(u32 init_crc, const u8 buf[], size_t len);
  35 static u32 (*fallback_crc32c)(u32 init_crc, const u8 buf[], size_t len);
  36
  37 static int crc32_pmull_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_pmull_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_pmull_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_pmull_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_pmull_update(struct shash_desc *desc, const u8 *data,
  76                          unsigned int length)
  77 {
  78         u32 *crc = shash_desc_ctx(desc);
  79         unsigned int l;
  80
  81         if ((u64)data % SCALE_F) {
  82                 l = min_t(u32, length, SCALE_F - ((u64)data % SCALE_F));
  83
  84                 *crc = fallback_crc32(*crc, data, l);
  85
  86                 data += l;
  87                 length -= l;
  88         }
  89
  90         if (length >= PMULL_MIN_LEN) {
  91                 l = round_down(length, SCALE_F);
  92
  93                 kernel_neon_begin_partial(10);
  94                 *crc = crc32_pmull_le(data, l, *crc);
  95                 kernel_neon_end();
  96
  97                 data += l;
  98                 length -= l;
  99         }
 100
 101         if (length > 0)
 102                 *crc = fallback_crc32(*crc, data, length);
 103
 104         return 0;
 105 }
 106
 107 static int crc32c_pmull_update(struct shash_desc *desc, const u8 *data,
 108                          unsigned int length)
 109 {
 110         u32 *crc = shash_desc_ctx(desc);
 111         unsigned int l;
 112
 113         if ((u64)data % SCALE_F) {
 114                 l = min_t(u32, length, SCALE_F - ((u64)data % SCALE_F));
 115
 116                 *crc = fallback_crc32c(*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_partial(10);
 126                 *crc = crc32c_pmull_le(data, l, *crc);
 127                 kernel_neon_end();
 128
 129                 data += l;
 130                 length -= l;
 131         }
 132
 133         if (length > 0) {
 134                 *crc = fallback_crc32c(*crc, data, length);
 135         }
 136
 137         return 0;
 138 }
 139
 140 static int crc32_pmull_final(struct shash_desc *desc, u8 *out)
 141 {
 142         u32 *crc = shash_desc_ctx(desc);
 143
 144         put_unaligned_le32(*crc, out);
 145         return 0;
 146 }
 147
 148 static int crc32c_pmull_final(struct shash_desc *desc, u8 *out)
 149 {
 150         u32 *crc = shash_desc_ctx(desc);
 151
 152         put_unaligned_le32(~*crc, out);
 153         return 0;
 154 }
 155
 156 static struct shash_alg crc32_pmull_algs[] = { {
 157         .setkey                 = crc32_pmull_setkey,
 158         .init                   = crc32_pmull_init,
 159         .update                 = crc32_pmull_update,
 160         .final                  = crc32_pmull_final,
 161         .descsize               = sizeof(u32),
 162         .digestsize             = sizeof(u32),
 163
 164         .base.cra_ctxsize       = sizeof(u32),
 165         .base.cra_init          = crc32_pmull_cra_init,
 166         .base.cra_name          = "crc32",
 167         .base.cra_driver_name   = "crc32-arm64-ce",
 168         .base.cra_priority      = 200,
 169         .base.cra_blocksize     = 1,
 170         .base.cra_module        = THIS_MODULE,
 171 }, {
 172         .setkey                 = crc32_pmull_setkey,
 173         .init                   = crc32_pmull_init,
 174         .update                 = crc32c_pmull_update,
 175         .final                  = crc32c_pmull_final,
 176         .descsize               = sizeof(u32),
 177         .digestsize             = sizeof(u32),
 178
 179         .base.cra_ctxsize       = sizeof(u32),
 180         .base.cra_init          = crc32c_pmull_cra_init,
 181         .base.cra_name          = "crc32c",
 182         .base.cra_driver_name   = "crc32c-arm64-ce",
 183         .base.cra_priority      = 200,
 184         .base.cra_blocksize     = 1,
 185         .base.cra_module        = THIS_MODULE,
 186 } };
 187
 188 static int __init crc32_pmull_mod_init(void)
 189 {
 190         if (elf_hwcap & HWCAP_CRC32) {
 191                 fallback_crc32 = crc32_armv8_le;
 192                 fallback_crc32c = crc32c_armv8_le;
 193         } else {
 194                 fallback_crc32 = crc32_le;
 195                 fallback_crc32c = __crc32c_le;
 196         }
 197
 198         return crypto_register_shashes(crc32_pmull_algs,
 199                                        ARRAY_SIZE(crc32_pmull_algs));
 200 }
 201
 202 static void __exit crc32_pmull_mod_exit(void)
 203 {
 204         crypto_unregister_shashes(crc32_pmull_algs,
 205                                   ARRAY_SIZE(crc32_pmull_algs));
 206 }
 207
 208 module_cpu_feature_match(PMULL, crc32_pmull_mod_init);
 209 module_exit(crc32_pmull_mod_exit);
 210
 211 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 212 MODULE_LICENSE("GPL v2");