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serenity/Kernel/Arch/riscv64/PageDirectory.cpp
Sönke Holz 8878e0c815 Kernel/riscv64: Implement everything in PageDirectory.cpp
This code is heavily based on aarch64's PageDirectory.cpp.
2024-01-29 05:17:03 -07:00

113 lines
3.6 KiB
C++

/*
* Copyright (c) 2023, Sönke Holz <sholz8530@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <AK/Singleton.h>
#include <Kernel/Arch/PageDirectory.h>
#include <Kernel/Interrupts/InterruptDisabler.h>
#include <Kernel/Library/LockRefPtr.h>
#include <Kernel/Sections.h>
#include <Kernel/Tasks/Process.h>
#include <Kernel/Tasks/Thread.h>
namespace Kernel::Memory {
struct SATPMap {
SpinlockProtected<IntrusiveRedBlackTree<&PageDirectory::m_tree_node>, LockRank::None> map {};
};
static Singleton<SATPMap> s_satp_map;
void PageDirectory::register_page_directory(PageDirectory* page_directory)
{
s_satp_map->map.with([&](auto& map) {
map.insert(bit_cast<FlatPtr>(page_directory->satp()), *page_directory);
});
}
void PageDirectory::deregister_page_directory(PageDirectory* page_directory)
{
s_satp_map->map.with([&](auto& map) {
map.remove(bit_cast<FlatPtr>(page_directory->satp()));
});
}
ErrorOr<NonnullLockRefPtr<PageDirectory>> PageDirectory::try_create_for_userspace(Process& process)
{
auto directory = TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) PageDirectory));
directory->m_process = &process;
directory->m_directory_table = TRY(MM.allocate_physical_page());
auto kernel_pd_index = (kernel_mapping_base >> VPN_2_OFFSET) & PAGE_TABLE_INDEX_MASK;
for (size_t i = 0; i < kernel_pd_index; i++) {
directory->m_directory_pages[i] = TRY(MM.allocate_physical_page());
}
// Share the top 1 GiB of kernel-only mappings (>=kernel_mapping_base)
directory->m_directory_pages[kernel_pd_index] = MM.kernel_page_directory().m_directory_pages[kernel_pd_index];
{
InterruptDisabler disabler;
auto& table = *reinterpret_cast<PageDirectoryPointerTable*>(MM.quickmap_page(*directory->m_directory_table));
for (size_t i = 0; i < array_size(directory->m_directory_pages); i++) {
if (directory->m_directory_pages[i] != nullptr) {
table.raw[i] = ((directory->m_directory_pages[i]->paddr().get()) >> PADDR_PPN_OFFSET) << PTE_PPN_OFFSET;
table.raw[i] |= to_underlying(PageTableEntryBits::Valid);
}
}
MM.unquickmap_page();
}
register_page_directory(directory);
return directory;
}
LockRefPtr<PageDirectory> PageDirectory::find_current()
{
return s_satp_map->map.with([&](auto& map) {
return map.find(bit_cast<FlatPtr>(RISCV64::CSR::SATP::read()));
});
}
void activate_kernel_page_directory(PageDirectory const& page_directory)
{
RISCV64::CSR::SATP::write(page_directory.satp());
Processor::flush_entire_tlb_local();
}
void activate_page_directory(PageDirectory const& page_directory, Thread* thread)
{
auto const satp = page_directory.satp();
thread->regs().satp = satp;
RISCV64::CSR::SATP::write(satp);
Processor::flush_entire_tlb_local();
}
UNMAP_AFTER_INIT NonnullLockRefPtr<PageDirectory> PageDirectory::must_create_kernel_page_directory()
{
return adopt_lock_ref_if_nonnull(new (nothrow) PageDirectory).release_nonnull();
}
PageDirectory::PageDirectory() = default;
UNMAP_AFTER_INIT void PageDirectory::allocate_kernel_directory()
{
dmesgln("MM: boot_pdpt @ {}", boot_pdpt);
dmesgln("MM: boot_pd_kernel @ {}", boot_pd_kernel);
m_directory_table = PhysicalPage::create(boot_pdpt, MayReturnToFreeList::No);
m_directory_pages[(kernel_mapping_base >> VPN_2_OFFSET) & PAGE_TABLE_INDEX_MASK] = PhysicalPage::create(boot_pd_kernel, MayReturnToFreeList::No);
}
PageDirectory::~PageDirectory()
{
if (is_root_table_initialized()) {
deregister_page_directory(this);
}
}
}