memorymanagement.cpp

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#include <memory/memorymanagement.h>
#include <common/logger.h>
#include <processes/scheduler.h>
 
using namespace MaxOS;
using namespace MaxOS::memory;
using namespace MaxOS::memory::allocator;
using namespace MaxOS::common;
using namespace MaxOS::processes;
using namespace MaxOS::system;
 
BumpMemoryManager::BumpMemoryManager(VirtualMemoryManager* virtual_memory_manager)
    : m_virtual_memory_manager(virtual_memory_manager)
{
 
    // Create the VMM if not provided
    if(m_virtual_memory_manager == nullptr)
        m_virtual_memory_manager = new VirtualMemoryManager();
 
    // Set up the first chunk of memory
    auto address = (uintptr_t)m_virtual_memory_manager->allocate(PAGE_SIZE, 0);
    setup_region(address, PAGE_SIZE);
 
}
 
BumpMemoryManager::~BumpMemoryManager() {
 
    // Free the VMM (if this is not the kernel memory manager)
    if(m_virtual_memory_manager != nullptr)
        delete m_virtual_memory_manager;
 
}
 
void* BumpMemoryManager::allocate_extra_space(size_t requested_size, size_t& actual_size) {
 
    // Create a new chunk of memory
    auto* chunk = m_virtual_memory_manager->allocate(requested_size, actual_size, PRESENT | WRITE | NO_EXECUTE);
    ASSERT(chunk != nullptr, "Out of memory - kernel cannot allocate any more memory");
 
    return chunk;
 
}
 
 
VirtualMemoryManager* BumpMemoryManager::vmm() {
 
    return m_virtual_memory_manager;
}
 
 
void BumpMemoryManager::switch_active_memory_manager(BumpMemoryManager* manager) {
 
    // Make sure there is a manager
    if(manager == nullptr)
        return;
 
    // Switch the address space
    asm volatile("mov %0, %%cr3"::"r"((uint64_t) manager->m_virtual_memory_manager->pml4_root_address_physical()) : "memory");
 
}
 
MemoryManager::MemoryManager(VirtualMemoryManager* vmm)
: BumpMemoryManager(vmm)
{
 
    // First memory manager is the kernel memory manager
    if(s_kernel_memory_manager == nullptr)
        s_kernel_memory_manager = this;
 
}
 
MemoryManager::~MemoryManager() {
 
    // Remove the kernel reference to this
    if(s_kernel_memory_manager == this)
        s_kernel_memory_manager = nullptr;
}
 
void* MemoryManager::malloc(size_t size) {
 
    return GlobalScheduler::current_process()->memory_manager->allocate(size);
}
 
void* MemoryManager::kmalloc(size_t size) {
 
    // Make sure there is a kernel memory manager
    if(s_kernel_memory_manager == nullptr)
        return nullptr;
 
    return s_kernel_memory_manager->allocate(size);
}
 
void MemoryManager::free(void* pointer) {
 
    return  GlobalScheduler::current_process()->memory_manager->unallocate(pointer);
}
 
void MemoryManager::kfree(void* pointer) {
 
    // Make sure there is a kernel memory manager
    if(s_kernel_memory_manager == nullptr)
        return;
 
    s_kernel_memory_manager->unallocate(pointer);
}
 
//Redefine the default object functions with memory orientated ones (defaults disabled in makefile)