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/* -------------------------------------------
Copyright (C) 2024-2025, Amlal El Mahrouss, licensed under the Apache 2.0 license.
------------------------------------------- */
#ifdef __NE_AMD64__
#include <HALKit/AMD64/Paging.h>
#elif defined(__NE_ARM64__)
#include <HALKit/ARM64/Paging.h>
#endif
#include <ArchKit/ArchKit.h>
#include <NeKit/KernelPanic.h>
#define kBitMapMagic (0x10210U)
#define kBitMapMagIdx (0U)
#define kBitMapSizeIdx (1U)
#define kBitMapUsedIdx (2U)
///! @author Amlal El Mahrouss (amlal@nekernel.org)
namespace Kernel {
namespace HAL {
namespace Detail {
/***********************************************************************************/
/// \brief Proxy Interface to manage a bitmap allocator.
/***********************************************************************************/
class IBitMapProxy final {
public:
explicit IBitMapProxy() = default;
~IBitMapProxy() = default;
NE_COPY_DELETE(IBitMapProxy)
auto IsBitMap(VoidPtr page_ptr) -> Bool {
if (!page_ptr) return No;
UIntPtr* ptr_bit_set = reinterpret_cast<UIntPtr*>(page_ptr);
if (!ptr_bit_set[kBitMapMagIdx] || ptr_bit_set[kBitMapMagIdx] != kBitMapMagic) return No;
return Yes;
}
auto FreeBitMap(VoidPtr page_ptr) -> Bool {
if (this->IsBitMap(page_ptr) == No) return No;
UIntPtr* ptr_bit_set = reinterpret_cast<UIntPtr*>(page_ptr);
kBitMapCursor += ptr_bit_set[kBitMapSizeIdx];
ptr_bit_set[kBitMapMagIdx] = kBitMapMagic;
ptr_bit_set[kBitMapUsedIdx] = No;
this->GetBitMapStatus(ptr_bit_set);
return Yes;
}
UInt32 MakeMMFlags(Bool wr, Bool user) {
UInt32 flags = kMMFlagsPresent;
if (wr) flags |= kMMFlagsWr;
if (user) flags |= kMMFlagsUser;
return flags;
}
/***********************************************************************************/
/// @brief Iterate over availables bitmap, until we find a free entry.
/// @param base_ptr base pointer to look on.
/// @param size the size of the requested data structure.
/// @param wr is writable flag?
/// @param user is user flag?
/// @param pad additional padding added to **size**
/// @return The new free address, or nullptr.
/***********************************************************************************/
auto FindBitMap(VoidPtr base_ptr, SizeT size, Bool wr, Bool user, SizeT pad) -> VoidPtr {
if (!size) return nullptr;
if (kBitMapCursor > kKernelBitMpSize) {
err_global_get() = kErrorOutOfBitMapMemory;
(Void)(kout << "Bitmap limit reached, can't allocate more bitmaps." << kendl);
return nullptr;
}
VoidPtr base = reinterpret_cast<VoidPtr>((UIntPtr) base_ptr);
MUST_PASS(base);
STATIC SizeT biggest = 0UL;
while (YES) {
UIntPtr* ptr_bit_set = reinterpret_cast<UIntPtr*>(base);
if (ptr_bit_set[kBitMapMagIdx] == kBitMapMagic &&
ptr_bit_set[kBitMapSizeIdx] == (size + pad)) {
if (ptr_bit_set[kBitMapUsedIdx] == No) {
ptr_bit_set[kBitMapSizeIdx] = size + pad;
ptr_bit_set[kBitMapUsedIdx] = Yes;
this->GetBitMapStatus(ptr_bit_set);
UInt32 flags = this->MakeMMFlags(wr, user);
mm_map_page(ptr_bit_set, ptr_bit_set, flags);
if (biggest < (size + pad)) biggest = size + pad;
kBitMapCursor += size + pad;
return (VoidPtr) ptr_bit_set;
}
} else if (ptr_bit_set[kBitMapMagIdx] != kBitMapMagic) {
ptr_bit_set[kBitMapMagIdx] = kBitMapMagic;
ptr_bit_set[kBitMapSizeIdx] = (size + pad);
ptr_bit_set[kBitMapUsedIdx] = Yes;
this->GetBitMapStatus(ptr_bit_set);
UInt32 flags = this->MakeMMFlags(wr, user);
mm_map_page(ptr_bit_set, ptr_bit_set, flags);
if (biggest < (size + pad)) biggest = (size + pad);
kBitMapCursor += size + pad;
return (VoidPtr) ptr_bit_set;
}
UIntPtr raw_base = reinterpret_cast<UIntPtr>(base);
UIntPtr offset = (ptr_bit_set[kBitMapMagIdx] != kBitMapMagic)
? (size + pad)
: ptr_bit_set[kBitMapSizeIdx];
base = reinterpret_cast<VoidPtr>(raw_base + offset);
if (base == nullptr) return nullptr;
}
return nullptr;
}
/// @brief Print Bitmap status
auto GetBitMapStatus(UIntPtr* ptr_bit_set) -> Void {
if (!this->IsBitMap(ptr_bit_set)) {
(Void)(kout << "Not a BitMap: " << hex_number((UIntPtr) ptr_bit_set) << kendl);
return;
}
(Void)(kout << "Magic: " << hex_number(ptr_bit_set[kBitMapMagIdx]) << kendl);
(Void)(kout << "Is Allocated? " << (ptr_bit_set[kBitMapUsedIdx] ? "YES" : "NO") << kendl);
(Void)(kout << "Size of BitMap (B): " << number(ptr_bit_set[kBitMapSizeIdx]) << kendl);
(Void)(kout << "Size of BitMap (KIB): " << number(KIB(ptr_bit_set[kBitMapSizeIdx]))
<< kendl);
(Void)(kout << "Size of BitMap (MIB): " << number(MIB(ptr_bit_set[kBitMapSizeIdx]))
<< kendl);
(Void)(kout << "Size of BitMap (GIB): " << number(GIB(ptr_bit_set[kBitMapSizeIdx]))
<< kendl);
(Void)(kout << "Size of BitMap (TIB): " << number(TIB(ptr_bit_set[kBitMapSizeIdx]))
<< kendl);
(Void)(kout << "BitMap Address: " << hex_number((UIntPtr) ptr_bit_set) << kendl);
}
};
} // namespace Detail
auto mm_is_bitmap(VoidPtr ptr) -> BOOL {
Detail::IBitMapProxy bitmp;
return bitmp.IsBitMap(ptr);
}
/***********************************************************************************/
/// @brief Allocate a new page to be used by the OS.
/// @param wr read/write bit.
/// @param user user bit.
/// @return a new bitmap allocated pointer.
/***********************************************************************************/
auto mm_alloc_bitmap(Boolean wr, Boolean user, SizeT size, Bool is_page, SizeT pad) -> VoidPtr {
VoidPtr ptr_new = nullptr;
Detail::IBitMapProxy bitmp;
if (is_page) return nullptr;
ptr_new = bitmp.FindBitMap(kKernelBitMpStart, size, wr, user, pad);
if (!ptr_new) {
ke_panic(RUNTIME_CHECK_VIRTUAL_OUT_OF_MEM, "Out of memory bitmap");
return nullptr;
}
return ptr_new;
}
/***********************************************************************************/
/// @brief Free Bitmap, and mark it as absent.
/// @param ptr the pointer to free.
/***********************************************************************************/
auto mm_free_bitmap(VoidPtr ptr) -> Bool {
if (!ptr) return No;
Detail::IBitMapProxy bitmp;
Bool ret = bitmp.FreeBitMap(ptr);
return ret;
}
} // namespace HAL
} // namespace Kernel
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