// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CACHE_FLUSH_H
#define CACHE_FLUSH_H

#include <cpuid.h>

#include "magma_util/dlog.h"
#include "magma_util/macros.h"

namespace magma {

class CacheFlush {
 public:
  CacheFlush() {
    unsigned int a, b, c, d;
    if (__get_cpuid(1, &a, &b, &c, &d)) {
      cacheline_size_ = 8 * ((b >> 8) & 0xff);
    } else {
      DASSERT(false);
    }
    DASSERT(magma::is_pow2(cacheline_size_));
  }

  inline void clflush_range(void* start, size_t size) {
    const uint64_t mask = cacheline_size_ - 1;
    uint8_t* p = reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(start) & ~mask);
    uint8_t* end = reinterpret_cast<uint8_t*>(start) + size;

    __builtin_ia32_mfence();
    while (p < end) {
      __builtin_ia32_clflush(p);
      p += cacheline_size_;
    }
  }

 private:
  uint32_t cacheline_size_ = 64;
};

}  // namespace magma

#endif  // CACHE_FLUSH_H