// SPDX-License-Identifier: Apache-2.0
// Copyright 2024-2026, Amlal El Mahrouss (amlal@nekernel.org)
// Licensed under the Apache License, Version 2.0 (see LICENSE file)
// Official repository: https://github.com/ne-foss-org/nekernel

#ifndef HALKIT_PAGING_H
#define HALKIT_PAGING_H

/** ---------------------------------------------------

  * THIS FILE CONTAINS CODE FOR ARMV8 PAGING.

------------======================================== */

#ifdef __NE_ARM64__

#include <NeKit/Config.h>

#ifndef kPageMax
#define kPageMax (0x200)
#endif  //! kPageMax

#ifndef kPageAlign
#define kPageAlign (0x1000)
#endif  //! kPageAlign

#ifndef kPageSize
#define kPageSize (0x1000)
#endif  // !kPageSize

//! short format address range

#define c16KBPage 0b000
#define c8KBPage 0b001
#define c4KBPage 0b010
#define c2KBPage 0b011
#define c1KBPage 0b100
#define c512BPage 0b101
#define c256BPage 0b110
#define c128BPage 0b111

/// Long format address range

#define cPageMAll \
  { 0b000, 0b000 }
#define cPageMToMax(M) \
  { M, 0b000 }
#define cPageMaxToM(M) \
  { 0b000, M }
#define cPageMToN(M, N) \
  { M, N }

namespace Kernel::HAL {
struct PACKED PTE_4KB final {
  UInt64 Valid : 1;
  UInt64 Table : 1;
  UInt64 AttrIndex : 3;
  UInt64 NS : 1;
  UInt64 AP : 2;
  UInt64 SH : 2;
  UInt64 AF : 1;
  UInt64 NG : 1;
  UInt64 Reserved1 : 1;
  UInt64 Contiguous : 1;
  UInt64 Dirty : 1;
  UInt64 Reserved : 2;
  UInt64 PhysicalAddress : 36;
  UInt64 Reserved3 : 4;
  UInt64 PXN : 1;
  UInt64 XN : 1;
  UInt64 Reserved4 : 9;
};

namespace Detail {
  enum struct ControlRegisterBits {
    ProtectedModeEnable = 0,
    MonitorCoProcessor  = 1,
    Emulation           = 2,
    TaskSwitched        = 3,
    ExtensionType       = 4,
    NumericError        = 5,
    WriteProtect        = 16,
    AlignementMask      = 18,
    NotWriteThrough     = 29,
    CacheDisable        = 30,
    PageEnable          = 31,
  };

  inline UInt8 control_register_cast(ControlRegisterBits reg) { return static_cast<UInt8>(reg); }
}  // namespace Detail

struct PDE_4KB final {
  PTE_4KB ALIGN(kPageAlign) fEntries[kPageMax];
};

auto mm_alloc_bitmap(Boolean wr, Boolean user, SizeT size, Bool is_page, SizeT pad = 0) -> VoidPtr;
auto mm_free_bitmap(VoidPtr page_ptr) -> Bool;
}  // namespace Kernel::HAL

namespace Kernel {
typedef HAL::PTE_4KB PTE;
typedef HAL::PDE_4KB PDE;
}  // namespace Kernel

EXTERN_C void hal_flush_tlb();

#endif  // __NE_ARM64__

#endif