text: // SPDX-License-Identifier: GPL-2.0 OR MIT
  /*
   * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
   */
  
  #include <linux/simd.h>
  #include <asm/x86/cpufeature.h>
  #include <asm/processor.h>
  #include <asm/x86/fpu/api.h>
  
  asmlinkage void blake2s_compress_avx(struct blake2s_state *state,
  				     const u8 *block, const size_t nblocks,
  				     const u32 inc);
  asmlinkage void blake2s_compress_avx512(struct blake2s_state *state,
  					const u8 *block, const size_t nblocks,
  					const u32 inc);
  
  static bool blake2s_use_avx __ro_after_init;
  static bool blake2s_use_avx512 __ro_after_init;
  static bool *const blake2s_nobs[] __initconst = { &blake2s_use_avx512 };
  
  static void __init blake2s_fpu_init(void)
  {
  	blake2s_use_avx =
  		boot_cpu_has(X86_FEATURE_AVX) &&
  		cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL);
  #ifndef COMPAT_CANNOT_USE_AVX512
  	blake2s_use_avx512 =
  		boot_cpu_has(X86_FEATURE_AVX) &&
  		boot_cpu_has(X86_FEATURE_AVX2) &&
  		boot_cpu_has(X86_FEATURE_AVX512F) &&
  		boot_cpu_has(X86_FEATURE_AVX512VL) &&
  		cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM |
  				  XFEATURE_MASK_AVX512, NULL);
  #endif
  }
  
  static inline bool blake2s_compress_arch(struct blake2s_state *state,
  					 const u8 *block, size_t nblocks,
  					 const u32 inc)
  {
  	simd_context_t simd_context;
  	bool used_arch = false;
  
  	/* SIMD disables preemption, so relax after processing each page. */
  	BUILD_BUG_ON(PAGE_SIZE / BLAKE2S_BLOCK_SIZE < 8);
  
  	simd_get(&simd_context);
  
  	if (!IS_ENABLED(CONFIG_AS_AVX) || !blake2s_use_avx ||
  	    !simd_use(&simd_context))
  		goto out;
  	used_arch = true;
  
  	for (;;) {
  		const size_t blocks = min_t(size_t, nblocks,
  					    PAGE_SIZE / BLAKE2S_BLOCK_SIZE);
  
  		if (IS_ENABLED(CONFIG_AS_AVX512) && blake2s_use_avx512)
  			blake2s_compress_avx512(state, block, blocks, inc);
  		else
  			blake2s_compress_avx(state, block, blocks, inc);
  
  		nblocks -= blocks;
  		if (!nblocks)
  			break;
  		block += blocks * BLAKE2S_BLOCK_SIZE;
  		simd_relax(&simd_context);
  	}
  out:
  	simd_put(&simd_context);
  	return used_arch;
  }
  