From 31ac3260ed875647b692e21242d8b0811a696875 Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Tue, 16 May 2023 00:26:13 +0300
Subject: [PATCH] Kernel: MMU keeps track of the current

---
 kernel/arch/x86_64/MMU.cpp         | 8 ++++++++
 kernel/include/kernel/Memory/MMU.h | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/kernel/arch/x86_64/MMU.cpp b/kernel/arch/x86_64/MMU.cpp
index f8c309e4..67a079ce 100644
--- a/kernel/arch/x86_64/MMU.cpp
+++ b/kernel/arch/x86_64/MMU.cpp
@@ -18,6 +18,7 @@ namespace Kernel
 {
 	
 	static MMU* s_instance = nullptr;
+	static MMU* s_current = nullptr;
 
 	void MMU::initialize()
 	{
@@ -34,6 +35,12 @@ namespace Kernel
 		return *s_instance;
 	}
 
+	MMU& MMU::current()
+	{
+		ASSERT(s_current);
+		return *s_current;
+	}
+
 	static uint64_t* allocate_page_aligned_page()
 	{
 		void* page = kmalloc(PAGE_SIZE, PAGE_SIZE);
@@ -130,6 +137,7 @@ namespace Kernel
 	void MMU::load()
 	{
 		asm volatile("movq %0, %%cr3" :: "r"(m_highest_paging_struct));
+		s_current = this;
 	}
 
 	void MMU::identity_map_page(paddr_t address, flags_t flags)
diff --git a/kernel/include/kernel/Memory/MMU.h b/kernel/include/kernel/Memory/MMU.h
index 17728484..8e481608 100644
--- a/kernel/include/kernel/Memory/MMU.h
+++ b/kernel/include/kernel/Memory/MMU.h
@@ -20,6 +20,8 @@ namespace Kernel
 		static void initialize();
 		static MMU& get();
 
+		static MMU& current();
+
 		MMU();
 		~MMU();