/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * SHA-256 optimized for ARM64
 *
 * Copyright 2025 Google LLC
 */
#include <asm/neon.h>
#include <crypto/internal/simd.h>
#include <linux/cpufeature.h>

asmlinkage void sha256_block_data_order(struct sha256_block_state *state,
     const u8 *data, size_t nblocks);
asmlinkage void sha256_block_neon(struct sha256_block_state *state,
      const u8 *data, size_t nblocks);
asmlinkage size_t __sha256_ce_transform(struct sha256_block_state *state,
     const u8 *data, size_t nblocks);

static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce);

static void sha256_blocks(struct sha256_block_state *state,
     const u8 *data, size_t nblocks)
{
 if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
     static_branch_likely(&have_neon) && crypto_simd_usable()) {
  if (static_branch_likely(&have_ce)) {
   do {
    size_t rem;

    kernel_neon_begin();
    rem = __sha256_ce_transform(state,
           data, nblocks);
    kernel_neon_end();
    data += (nblocks - rem) * SHA256_BLOCK_SIZE;
    nblocks = rem;
   } while (nblocks);
  } else {
   kernel_neon_begin();
   sha256_block_neon(state, data, nblocks);
   kernel_neon_end();
  }
 } else {
  sha256_block_data_order(state, data, nblocks);
 }
}

#ifdef CONFIG_KERNEL_MODE_NEON
#define sha256_mod_init_arch sha256_mod_init_arch
static inline void sha256_mod_init_arch(void)
{
 if (cpu_have_named_feature(ASIMD)) {
  static_branch_enable(&have_neon);
  if (cpu_have_named_feature(SHA2))
   static_branch_enable(&have_ce);
 }
}
#endif /* CONFIG_KERNEL_MODE_NEON */