utility.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
#ifndef KERNEL_UTILITY_H
#define KERNEL_UTILITY_H
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/processor/types.h"
 
#include <config.h>
 
// Export memcpy et al
#include "pedigree/kernel/utilities/cpp.h"  // IWYU pragma: export
#include "pedigree/kernel/utilities/lib.h"  // IWYU pragma: export
 
#ifdef __cplusplus
#include <bit>
#endif
 
#ifdef __cplusplus
constexpr uint8_t BS8(uint8_t value) noexcept {
  return value;
}
 
constexpr uint16_t BS16(uint16_t value) noexcept {
  return std::byteswap(value);
}
 
constexpr uint32_t BS32(uint32_t value) noexcept {
  return std::byteswap(value);
}
 
constexpr uint64_t BS64(uint64_t value) noexcept {
  return std::byteswap(value);
}
#else
#define BS8(x) ((uint8_t)(x))
#define BS16(x) __builtin_bswap16((uint16_t)(x))
#define BS32(x) __builtin_bswap32((uint32_t)(x))
#define BS64(x) __builtin_bswap64((uint64_t)(x))
#endif
 
#if TARGET_IS_LITTLE_ENDIAN
 
#define LITTLE_TO_HOST8(x) (x)
#define LITTLE_TO_HOST16(x) (x)
#define LITTLE_TO_HOST32(x) (x)
#define LITTLE_TO_HOST64(x) (x)
 
#define HOST_TO_LITTLE8(x) (x)
#define HOST_TO_LITTLE16(x) (x)
#define HOST_TO_LITTLE32(x) (x)
#define HOST_TO_LITTLE64(x) (x)
 
#define BIG_TO_HOST8(x) BS8((x))
#define BIG_TO_HOST16(x) BS16((x))
#define BIG_TO_HOST32(x) BS32((x))
#define BIG_TO_HOST64(x) BS64((x))
 
#define HOST_TO_BIG8(x) BS8((x))
#define HOST_TO_BIG16(x) BS16((x))
#define HOST_TO_BIG32(x) BS32((x))
#define HOST_TO_BIG64(x) BS64((x))
 
#else  // else Big endian
 
#define BIG_TO_HOST8(x) (x)
#define BIG_TO_HOST16(x) (x)
#define BIG_TO_HOST32(x) (x)
#define BIG_TO_HOST64(x) (x)
 
#define HOST_TO_BIG8(x) (x)
#define HOST_TO_BIG16(x) (x)
#define HOST_TO_BIG32(x) (x)
#define HOST_TO_BIG64(x) (x)
 
#define LITTLE_TO_HOST8(x) BS8((x))
#define LITTLE_TO_HOST16(x) BS16((x))
#define LITTLE_TO_HOST32(x) BS32((x))
#define LITTLE_TO_HOST64(x) BS64((x))
 
#define HOST_TO_LITTLE8(x) BS8((x))
#define HOST_TO_LITTLE16(x) BS16((x))
#define HOST_TO_LITTLE32(x) BS32((x))
#define HOST_TO_LITTLE64(x) BS64((x))
 
#endif
 
#define MAX_FUNCTION_NAME 128
#define MAX_PARAMS 32
#define MAX_PARAM_LENGTH 64
 
EXPORTED_PUBLIC void* page_align(void* p) PURE;
 
#ifdef __cplusplus
template <typename T1, typename T2 = T1>
T2* adjust_pointer(T1* pointer, ssize_t offset) {
  return reinterpret_cast<T2*>(reinterpret_cast<intptr_t>(pointer) + offset);
}
 
template <typename T>
void swap(T a, T b) {
  T t = a;
  a = b;
  b = t;
}
 
template <typename T1, typename T2>
intptr_t pointer_diff(const T1* a, const T2* b) {
  return reinterpret_cast<uintptr_t>(b) - reinterpret_cast<uintptr_t>(a);
}
 
template <typename T1, typename T2>
constexpr intptr_t pointer_diff_const(T1* a, T2* b) {
  return reinterpret_cast<uintptr_t>(b) - reinterpret_cast<uintptr_t>(a);
}
 
template <typename T1, typename T2>
uintptr_t abs_difference(T1 a, T2 b) {
  intptr_t value = b - a;
  if (value < 0)
    value *= -1;
  return value;
}
#endif
 
#endif