arch/arm64/lib/crc-t10dif-glue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
   4  *
   5  * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
   6  */
   7
   8 #include <linux/cpufeature.h>
   9 #include <linux/crc-t10dif.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/simd.h>
  16
  17 #include <asm/neon.h>
  18 #include <asm/simd.h>
  19
  20 static DEFINE_STATIC_KEY_FALSE(have_asimd);
  21 static DEFINE_STATIC_KEY_FALSE(have_pmull);
  22
  23 #define CRC_T10DIF_PMULL_CHUNK_SIZE     16U
  24
  25 asmlinkage void crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len,
  26                                     u8 out[16]);
  27 asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
  28
  29 u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
  30 {
  31         if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
  32                 if (static_branch_likely(&have_pmull)) {
  33                         if (crypto_simd_usable()) {
  34                                 kernel_neon_begin();
  35                                 crc = crc_t10dif_pmull_p64(crc, data, length);
  36                                 kernel_neon_end();
  37                                 return crc;
  38                         }
  39                 } else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
  40                            static_branch_likely(&have_asimd) &&
  41                            crypto_simd_usable()) {
  42                         u8 buf[16];
  43
  44                         kernel_neon_begin();
  45                         crc_t10dif_pmull_p8(crc, data, length, buf);
  46                         kernel_neon_end();
  47
  48                         crc = 0;
  49                         data = buf;
  50                         length = sizeof(buf);
  51                 }
  52         }
  53         return crc_t10dif_generic(crc, data, length);
  54 }
  55 EXPORT_SYMBOL(crc_t10dif_arch);
  56
  57 static int __init crc_t10dif_arm64_init(void)
  58 {
  59         if (cpu_have_named_feature(ASIMD)) {
  60                 static_branch_enable(&have_asimd);
  61                 if (cpu_have_named_feature(PMULL))
  62                         static_branch_enable(&have_pmull);
  63         }
  64         return 0;
  65 }
  66 arch_initcall(crc_t10dif_arm64_init);
  67
  68 static void __exit crc_t10dif_arm64_exit(void)
  69 {
  70 }
  71 module_exit(crc_t10dif_arm64_exit);
  72
  73 bool crc_t10dif_is_optimized(void)
  74 {
  75         return static_key_enabled(&have_asimd);
  76 }
  77 EXPORT_SYMBOL(crc_t10dif_is_optimized);
  78
  79 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  80 MODULE_DESCRIPTION("CRC-T10DIF using arm64 NEON and Crypto Extensions");
  81 MODULE_LICENSE("GPL v2");