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Kernel: Add some bareboness functionality to map virtual addresses

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Bananymous
2023-04-19 23:51:36 +03:00
parent 0030f035be
commit ea0c9b639f
4 changed files with 65 additions and 57 deletions
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102
kernel/arch/x86_64/MMU.cpp
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@@ -90,54 +90,8 @@ MMU::~MMU()
void MMU::map_page(uintptr_t address, uint8_t flags)
{
ASSERT((address >> 48) == 0);
ASSERT(flags & Flags::Present);
bool should_invalidate = false;
address &= PAGE_MASK;
uint64_t pml4e = (address >> 39) & 0x1FF;
uint64_t pdpte = (address >> 30) & 0x1FF;
uint64_t pde = (address >> 21) & 0x1FF;
uint64_t pte = (address >> 12) & 0x1FF;
uint64_t* pml4 = m_highest_paging_struct;
if ((pml4[pml4e] & flags) != flags)
{
if (!(pml4[pml4e] & Flags::Present))
pml4[pml4e] = (uint64_t)allocate_page_aligned_page();
pml4[pml4e] = (pml4[pml4e] & PAGE_MASK) | flags;
should_invalidate = true;
}
uint64_t* pdpt = (uint64_t*)(pml4[pml4e] & PAGE_MASK);
if ((pdpt[pdpte] & flags) != flags)
{
if (!(pdpt[pdpte] & Flags::Present))
pdpt[pdpte] = (uint64_t)allocate_page_aligned_page();
pdpt[pdpte] = (pdpt[pdpte] & PAGE_MASK) | flags;
should_invalidate = true;
}
uint64_t* pd = (uint64_t*)(pdpt[pdpte] & PAGE_MASK);
if ((pd[pde] & flags) != flags)
{
if (!(pd[pde] & Flags::Present))
pd[pde] = (uint64_t)allocate_page_aligned_page();
pd[pde] = (pd[pde] & PAGE_MASK) | flags;
should_invalidate = true;
}
uint64_t* pt = (uint64_t*)(pd[pde] & PAGE_MASK);
if ((pt[pte] & flags) != flags)
{
pt[pte] = address | flags;
should_invalidate = true;
}
if (should_invalidate)
asm volatile("invlpg (%0)" :: "r"(address) : "memory");
map_page_at(address, address, flags);
}
void MMU::map_range(uintptr_t address, ptrdiff_t size, uint8_t flags)
@@ -195,3 +149,57 @@ void MMU::unmap_range(uintptr_t address, ptrdiff_t size)
for (uintptr_t page = s_page; page <= e_page; page += PAGE_SIZE)
unmap_page(page);
}
void MMU::map_page_at(paddr_t paddr, vaddr_t vaddr, uint8_t flags)
{
ASSERT((paddr >> 48) == 0);
ASSERT((vaddr >> 48) == 0);
ASSERT((paddr & ~PAGE_MASK) == 0);
ASSERT((vaddr & ~PAGE_MASK) == 0);;
ASSERT(flags & Flags::Present);
bool should_invalidate = false;
uint64_t pml4e = (vaddr >> 39) & 0x1FF;
uint64_t pdpte = (vaddr >> 30) & 0x1FF;
uint64_t pde = (vaddr >> 21) & 0x1FF;
uint64_t pte = (vaddr >> 12) & 0x1FF;
uint64_t* pml4 = m_highest_paging_struct;
if ((pml4[pml4e] & flags) != flags)
{
if (!(pml4[pml4e] & Flags::Present))
pml4[pml4e] = (uint64_t)allocate_page_aligned_page();
pml4[pml4e] = (pml4[pml4e] & PAGE_MASK) | flags;
should_invalidate = true;
}
uint64_t* pdpt = (uint64_t*)(pml4[pml4e] & PAGE_MASK);
if ((pdpt[pdpte] & flags) != flags)
{
if (!(pdpt[pdpte] & Flags::Present))
pdpt[pdpte] = (uint64_t)allocate_page_aligned_page();
pdpt[pdpte] = (pdpt[pdpte] & PAGE_MASK) | flags;
should_invalidate = true;
}
uint64_t* pd = (uint64_t*)(pdpt[pdpte] & PAGE_MASK);
if ((pd[pde] & flags) != flags)
{
if (!(pd[pde] & Flags::Present))
pd[pde] = (uint64_t)allocate_page_aligned_page();
pd[pde] = (pd[pde] & PAGE_MASK) | flags;
should_invalidate = true;
}
uint64_t* pt = (uint64_t*)(pd[pde] & PAGE_MASK);
if ((pt[pte] & flags) != flags)
{
pt[pte] = paddr | flags;
should_invalidate = true;
}
if (should_invalidate)
asm volatile("movq %0, %%cr3" :: "r"(m_highest_paging_struct));
}