Wrote physical memory manager

kernel/include/paging.h

@@ -3,34 +3,35 @@
 
 #include <kernel.h>
 
-#define PAGE_FLAG_PRESENT	(1 << 0) // Page is present in the table
-#define PAGE_FLAG_WRITE		(1 << 1) // Read-write
-#define PAGE_FLAG_USER		(1 << 2) // User-mode (DPL3) access allowed
-#define PAGE_FLAG_PWT		(1 << 3) // Page write-thru
-#define PAGE_FLAG_NOCACHE	(1 << 4) // Cache disable
-#define PAGE_FLAG_ACCESSED	(1 << 5) // Indicates whether page was accessed
-#define PAGE_FLAG_DIRTY		(1 << 6) // Page size (valid for PD and PDPT only)
-#define PAGE_FLAG_PAT		(1 << 7) // Page Attribute Table (valid for PT only)
-#define PAGE_FLAG_GLOBAL	(1 << 8) // Indicates the page is globally cached
-#define PAGE_FLAG_SHARED	(1 << 9) // Userland page is shared
+#define PTE_FLAG_PRESENT	(1ULL << 0) // Page is present in the table
+#define PTE_FLAG_WRITE		(1ULL << 1) // Read-write
+#define PTE_FLAG_USER		(1ULL << 2) // User-mode (DPL3) access allowed
+#define PTE_FLAG_PWT		(1ULL << 3) // Page write-thru
+#define PTE_FLAG_NOCACHE	(1ULL << 4) // Cache disable
+#define PTE_FLAG_ACCESSED	(1ULL << 5) // Indicates whether page was accessed
+#define PTE_FLAG_DIRTY		(1ULL << 6) // Page size (valid for PD and PDPT only)
+#define PTE_FLAG_PAT		(1ULL << 7) // Page Attribute Table (valid for PT only)
+#define PTE_FLAG_GLOBAL		(1ULL << 8) // Indicates the page is globally cached
+#define PTE_FLAG_SHARED		(1ULL << 9) // Userland page is shared
+#define PTE_FLAG_NOEXEC		(1ULL << 63) // No execute
 // Region caching according to the Limine protocol
-#define PAGE_FLAG_CACHE	(PAGE_FLAG_PWT | PAGE_FLAG_PAT)
+#define PTE_FLAG_CACHE		(PTE_FLAG_PWT | PTE_FLAG_PAT)
+
+#define PTE_ADDR_MASK	0x000FFFFFFFFFFFFFF000ULL
+#define PTE_ADDR(_pte)	((_pte) & PAGE_ADDR_MASK)
 
 #define PAGE_SIZE	0x1000
 #define PAGE_SIZE_LARGE	0x200000
 #define PAGE_SIZE_HUGE	0x40000000
 
-#define PHYS_ADDR(_x) ((_x) & ~0xFFF)
+// From the Linux kernel source
+// WARN: This will only invalidate on one core
+static inline void pag_invalidate(size_t vaddr) { __asm__ volatile("invlpg (%0)" :: "r" (vaddr) : "memory"); }
 
 int	pag_init(void);
-void	pag_map(size_t vaddr, size_t paddr, size_t flags);
-size_t	pag_umap(size_t vaddr);
-size_t	pag_virt_to_phys(size_t vaddr);
-size_t*	pag_get_pagedir();
-size_t*	pag_get_task_pagedir(void* task);
-void	pag_set_pagedir(size_t* pagedir);
-size_t*	pag_alloc_pagedir();
-void	pag_free_pagedir(size_t* pagedir);
-void	pag_invalidate(size_t vaddr);
+void	pag_map(uint64_t* pml4, void* vaddr, void* paddr, uint64_t flags);
+void	pag_unmap(uint64_t* pml4, void* vaddr);
+void	pag_switch(uint64_t* pml4);
+uint64_t* pag_new_pml(void);
 
 #endif