arch/sparc/lib/crc32_glue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Glue code for CRC32C optimized for sparc64 crypto opcodes.
   3  *
   4  * This is based largely upon arch/x86/crypto/crc32c-intel.c
   5  *
   6  * Copyright (C) 2008 Intel Corporation
   7  * Authors: Austin Zhang <austin_zhang@linux.intel.com>
   8  *          Kent Liu <kent.liu@intel.com>
   9  */
  10
  11 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/crc32.h>
  17 #include <asm/pstate.h>
  18 #include <asm/elf.h>
  19
  20 static DEFINE_STATIC_KEY_FALSE(have_crc32c_opcode);
  21
  22 u32 crc32_le_arch(u32 crc, const u8 *data, size_t len)
  23 {
  24         return crc32_le_base(crc, data, len);
  25 }
  26 EXPORT_SYMBOL(crc32_le_arch);
  27
  28 void crc32c_sparc64(u32 *crcp, const u64 *data, size_t len);
  29
  30 u32 crc32c_le_arch(u32 crc, const u8 *data, size_t len)
  31 {
  32         size_t n = -(uintptr_t)data & 7;
  33
  34         if (!static_branch_likely(&have_crc32c_opcode))
  35                 return crc32c_le_base(crc, data, len);
  36
  37         if (n) {
  38                 /* Data isn't 8-byte aligned.  Align it. */
  39                 n = min(n, len);
  40                 crc = crc32c_le_base(crc, data, n);
  41                 data += n;
  42                 len -= n;
  43         }
  44         n = len & ~7U;
  45         if (n) {
  46                 crc32c_sparc64(&crc, (const u64 *)data, n);
  47                 data += n;
  48                 len -= n;
  49         }
  50         if (len)
  51                 crc = crc32c_le_base(crc, data, len);
  52         return crc;
  53 }
  54 EXPORT_SYMBOL(crc32c_le_arch);
  55
  56 u32 crc32_be_arch(u32 crc, const u8 *data, size_t len)
  57 {
  58         return crc32_be_base(crc, data, len);
  59 }
  60 EXPORT_SYMBOL(crc32_be_arch);
  61
  62 static int __init crc32_sparc_init(void)
  63 {
  64         unsigned long cfr;
  65
  66         if (!(sparc64_elf_hwcap & HWCAP_SPARC_CRYPTO))
  67                 return 0;
  68
  69         __asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr));
  70         if (!(cfr & CFR_CRC32C))
  71                 return 0;
  72
  73         static_branch_enable(&have_crc32c_opcode);
  74         pr_info("Using sparc64 crc32c opcode optimized CRC32C implementation\n");
  75         return 0;
  76 }
  77 arch_initcall(crc32_sparc_init);
  78
  79 static void __exit crc32_sparc_exit(void)
  80 {
  81 }
  82 module_exit(crc32_sparc_exit);
  83
  84 u32 crc32_optimizations(void)
  85 {
  86         if (static_key_enabled(&have_crc32c_opcode))
  87                 return CRC32C_OPTIMIZATION;
  88         return 0;
  89 }
  90 EXPORT_SYMBOL(crc32_optimizations);
  91
  92 MODULE_LICENSE("GPL");
  93 MODULE_DESCRIPTION("CRC32c (Castagnoli), sparc64 crc32c opcode accelerated");