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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
   4  *
   5  * Copyright (C) 2016 Linaro Ltd <[email protected]>
   6  */
   7
   8 #include <linux/crc-t10dif.h>
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/string.h>
  13
  14 #include <crypto/internal/simd.h>
  15
  16 #include <asm/neon.h>
  17 #include <asm/simd.h>
  18
  19 static DEFINE_STATIC_KEY_FALSE(have_neon);
  20 static DEFINE_STATIC_KEY_FALSE(have_pmull);
  21
  22 #define CRC_T10DIF_PMULL_CHUNK_SIZE     16U
  23
  24 asmlinkage u16 crc_t10dif_pmull64(u16 init_crc, const u8 *buf, size_t len);
  25 asmlinkage void crc_t10dif_pmull8(u16 init_crc, const u8 *buf, size_t len,
  26                                   u8 out[16]);
  27
  28 u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
  29 {
  30         if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
  31                 if (static_branch_likely(&have_pmull)) {
  32                         if (crypto_simd_usable()) {
  33                                 kernel_neon_begin();
  34                                 crc = crc_t10dif_pmull64(crc, data, length);
  35                                 kernel_neon_end();
  36                                 return crc;
  37                         }
  38                 } else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
  39                            static_branch_likely(&have_neon) &&
  40                            crypto_simd_usable()) {
  41                         u8 buf[16] __aligned(16);
  42
  43                         kernel_neon_begin();
  44                         crc_t10dif_pmull8(crc, data, length, buf);
  45                         kernel_neon_end();
  46
  47                         crc = 0;
  48                         data = buf;
  49                         length = sizeof(buf);
  50                 }
  51         }
  52         return crc_t10dif_generic(crc, data, length);
  53 }
  54 EXPORT_SYMBOL(crc_t10dif_arch);
  55
  56 static int __init crc_t10dif_arm_init(void)
  57 {
  58         if (elf_hwcap & HWCAP_NEON) {
  59                 static_branch_enable(&have_neon);
  60                 if (elf_hwcap2 & HWCAP2_PMULL)
  61                         static_branch_enable(&have_pmull);
  62         }
  63         return 0;
  64 }
  65 arch_initcall(crc_t10dif_arm_init);
  66
  67 static void __exit crc_t10dif_arm_exit(void)
  68 {
  69 }
  70 module_exit(crc_t10dif_arm_exit);
  71
  72 bool crc_t10dif_is_optimized(void)
  73 {
  74         return static_key_enabled(&have_neon);
  75 }
  76 EXPORT_SYMBOL(crc_t10dif_is_optimized);
  77
  78 MODULE_AUTHOR("Ard Biesheuvel <[email protected]>");
  79 MODULE_DESCRIPTION("Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions");
  80 MODULE_LICENSE("GPL v2");