// SPDX-License-Identifier: GPL-3.0-or-later
// Copyright (c) 2026 0xKSor

#pragma once
#include <Types.h>
#include <VM/PMM.h>
#include "../Common/bootinfo.h"

enum VMPTEFlags {
    // Descriptor type (bits [1:0])
    kPTEValid      = (1ULL << 0),  // 1 = Valid (fault if 0)
    kPTETable      = (1ULL << 1),  // For L0/L1/L2: table descriptor (bits[1:0]=11)
    kPTEPage       = (1ULL << 1),  // For L3: page descriptor (same bit, bits[1:0]=11)

    // MAIR attribute index (bits [4:2])
    kPTENormalMem  = (0ULL << 2),  // AttrIndx 0 → MAIR[7:0] = 0xFF (Normal, WB Cacheable)
    kPTEDeviceMem  = (1ULL << 2),  // AttrIndx 1 → MAIR[15:8] = 0x00 (Device-nGnRnE)

    // Leaf entry AP[2:1] (bits [7:6]):
    //   AP[1] (bit 6): 0 = EL0 blocked, 1 = EL0 allowed
    //   AP[2] (bit 7): 0 = Read/Write, 1 = Read-only
    kPTEUser       = (1ULL << 6),  // AP[1]=1: allow EL0 access
    kPTEAccessRW   = (0ULL << 7),  // AP[2]=0: writable for permitted levels
    kPTEAccessRO   = (1ULL << 7),  // AP[2]=1: read-only for all levels

    // Table descriptor APTable[1:0] (bits [62:61]):
    //   00 = no restriction, 01 = block EL0, 10 = reserved, 11 = read-only for all
    kPTETableNoEL0 = (1ULL << 61), // APTable[0]=1: prevent EL0 table walk

    kPTEInnerShare = (3ULL << 8),  // Inner Shareable (SMP safe)
    kPTEAccessFlag = (1ULL << 10), // Access Flag (MUST be 1 to avoid faults)
    kPTEPrivNX     = (1ULL << 53), // PXN: Privileged Execute Never
    kPTEUserNX     = (1ULL << 54)  // UXN: Unprivileged Execute Never
};

enum {
    kVMKernelVMA   = 0xFFFFFFFF80000000,
    kHHDMOffset    = 0xFFFF888000000000,
    kVMFbVirtBase  = 0xFFFFFFFFFC000000,
    kKernelPhysBase = 0x40100000,
};


static inline Address VMKernelVirtToPhys(Address virt) {
    return virt - 0xFFFFFFFF80100000 + kKernelPhysBase;
}

static inline Address VMPhysToHHDM(Address phys) {
    return phys + kHHDMOffset;
}

static inline Address VMHHDMToPhys(Address virt) {
    return virt - kHHDMOffset;
}

extern Address* gVMKernelL0Table;
extern Address gVMKernelL0Physical;

Address* VMMMapPage(Address* l0Table, Address phys, Address virt, UInt64 flags);
void VMMUnmapPage(Address* l0Table, Address virt);
Pointer VMMGetOrAllocatePage(Address* l0Table, Address virt, UInt64 flags);
void VMMInitialize(VMBootMemoryMap* bootMap, Bootinfo* info);