/* See COPYRIGHT for copyright information. */

#ifndef _KERN_PMAP_H_
#define _KERN_PMAP_H_

#include <inc/pmap.h>
#include <inc/assert.h>


/* This macro takes a user supplied address and turns it into
 * something that will cause a fault if it is a kernel address.  ULIM
 * itself is guaranteed never to contain a valid page.  
*/
#define TRUP(_p)   						\
({								\
	register typeof((_p)) __m_p = (_p);			\
	(u_int) __m_p > ULIM ? (typeof(_p)) ULIM : __m_p;	\
})

// translates from virtual address to physical address
#define PADDR(kva)						\
({								\
	u_long a = (u_long) (kva);				\
	if (a < KERNBASE)					\
		panic("PADDR called with invalid kva %08lx", a);\
	a - KERNBASE;						\
})

// translates from physical address to kernel virtual address
#define KADDR(pa)						\
({								\
	u_long ppn = PPN(pa);					\
	if (ppn >= npage)					\
		panic("KADDR called with invalid pa %08lx", (u_long)pa);\
	(pa) + KERNBASE;					\
})



extern char bootstacktop[], bootstack[];

extern u_long npage;


extern struct Segdesc gdt[];
extern struct Pseudodesc gdt_pd;
extern struct Page *pages;
extern u_long npage;
extern u_long boot_cr3;
extern Pde *boot_pgdir;

void i386_vm_init();
void i386_detect_memory();
void page_init(void);
void page_check(void);
int  page_alloc(struct Page **);
void page_free(struct Page *);
int  page_insert(Pde *, struct Page *, u_long, u_int);
void page_remove(Pde *, u_long va);
struct Page *page_lookup(Pde*, u_long, Pte**);
void page_decref(struct Page*);
void tlb_invalidate(Pde *, u_long va);

static inline u_long
page2ppn(struct Page *pp)
{
	return pp - pages;
}

static inline u_long
page2pa(struct Page *pp)
{
	return page2ppn(pp)<<PGSHIFT;
}

static inline struct Page *
pa2page(u_long pa)
{
	if (PPN(pa) >= npage)
		panic("pa2page called with invalid pa");
	return &pages[PPN(pa)];
}

static inline u_long
page2kva(struct Page *pp)
{
	return KADDR(page2pa(pp));
}

int pgdir_walk(Pde *pgdir, u_long va, int create, Pte **ppte);
u_long va2pa(Pde *pgdir, u_long va);

void * vmemcpy(Pde *pgdir, void *dst, const void *src, size_t n);
void * vmemset(Pde *pgdir, void *dst, int c, size_t n);

#endif /* _KERN_PMAP_H_ */