ladybird/Kernel/VM/PhysicalPage.cpp

#include <Kernel/VM/PhysicalPage.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/kmalloc.h>

Retained<PhysicalPage> PhysicalPage::create_eternal(PhysicalAddress paddr, bool supervisor)
{
    void* slot = kmalloc_eternal(sizeof(PhysicalPage));
    new (slot) PhysicalPage(paddr, supervisor);
    return adopt(*(PhysicalPage*)slot);
}

Retained<PhysicalPage> PhysicalPage::create(PhysicalAddress paddr, bool supervisor)
{
    void* slot = kmalloc(sizeof(PhysicalPage));
    new (slot) PhysicalPage(paddr, supervisor, false);
    return adopt(*(PhysicalPage*)slot);
}

PhysicalPage::PhysicalPage(PhysicalAddress paddr, bool supervisor, bool may_return_to_freelist)
    : m_may_return_to_freelist(may_return_to_freelist)
    , m_supervisor(supervisor)
    , m_paddr(paddr)
{
    if (supervisor)
        ++MemoryManager::s_super_physical_pages_in_existence;
    else
        ++MemoryManager::s_user_physical_pages_in_existence;
}

void PhysicalPage::return_to_freelist()
{
    ASSERT((paddr().get() & ~PAGE_MASK) == 0);
    InterruptDisabler disabler;
    m_retain_count = 1;
    if (m_supervisor)
        MM.m_free_supervisor_physical_pages.append(adopt(*this));
    else
        MM.m_free_physical_pages.append(adopt(*this));
#ifdef MM_DEBUG
    dbgprintf("MM: P%x released to freelist\n", m_paddr.get());
#endif
}