#ifndef _ASM_X86_XEN_PAGE_H

#define _ASM_X86_XEN_PAGE_H

#include <linux/pfn.h>

#include <asm/uaccess.h>

#include <asm/pgtable.h>

#include <xen/features.h>

/* Xen machine address */

typedef struct xmaddr {

	phys_addr_t maddr;

} xmaddr_t;

/* Xen pseudo-physical address */

typedef struct xpaddr {

	phys_addr_t paddr;

} xpaddr_t;

#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })

#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })

/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/

#define INVALID_P2M_ENTRY	(~0UL)

#define FOREIGN_FRAME_BIT	(1UL<<31)

#define FOREIGN_FRAME(m)	((m) | FOREIGN_FRAME_BIT)

/* Maximum amount of memory we can handle in a domain in pages */

#define MAX_DOMAIN_PAGES						\

    ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE))

extern unsigned long get_phys_to_machine(unsigned long pfn);

extern void set_phys_to_machine(unsigned long pfn, unsigned long mfn);

static inline unsigned long pfn_to_mfn(unsigned long pfn)

{

	if (xen_feature(XENFEAT_auto_translated_physmap))

		return pfn;

	return get_phys_to_machine(pfn) & ~FOREIGN_FRAME_BIT;

}

static inline int phys_to_machine_mapping_valid(unsigned long pfn)

{

	if (xen_feature(XENFEAT_auto_translated_physmap))

		return 1;

	return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;

}

static inline unsigned long mfn_to_pfn(unsigned long mfn)

{

	unsigned long pfn;

	if (xen_feature(XENFEAT_auto_translated_physmap))

		return mfn;

#if 0

	if (unlikely((mfn >> machine_to_phys_order) != 0))

		return max_mapnr;

#endif

	pfn = 0;

	/*

	 * The array access can fail (e.g., device space beyond end of RAM).

	 * In such cases it doesn't matter what we return (we return garbage),

	 * but we must handle the fault without crashing!

	 */

	__get_user(pfn, &machine_to_phys_mapping[mfn]);

	return pfn;

}

static inline xmaddr_t phys_to_machine(xpaddr_t phys)

{

	unsigned offset = phys.paddr & ~PAGE_MASK;

	return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);

}

static inline xpaddr_t machine_to_phys(xmaddr_t machine)

{

	unsigned offset = machine.maddr & ~PAGE_MASK;

	return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);

}

/*

 * We detect special mappings in one of two ways:

 *  1. If the MFN is an I/O page then Xen will set the m2p entry

 *     to be outside our maximum possible pseudophys range.

 *  2. If the MFN belongs to a different domain then we will certainly

 *     not have MFN in our p2m table. Conversely, if the page is ours,

 *     then we'll have p2m(m2p(MFN))==MFN.

 * If we detect a special mapping then it doesn't have a 'struct page'.

 * We force !pfn_valid() by returning an out-of-range pointer.

 *

 * NB. These checks require that, for any MFN that is not in our reservation,

 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if

 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.

 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.

 *

 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*

 *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we

 *      require. In all the cases we care about, the FOREIGN_FRAME bit is

 *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.

 */

static inline unsigned long mfn_to_local_pfn(unsigned long mfn)

{

	extern unsigned long max_mapnr;

	unsigned long pfn = mfn_to_pfn(mfn);

	if ((pfn < max_mapnr)

	    && !xen_feature(XENFEAT_auto_translated_physmap)

	    && (get_phys_to_machine(pfn) != mfn))

		return max_mapnr; /* force !pfn_valid() */

	/* XXX fixme; not true with sparsemem */

	return pfn;

}

/* VIRT <-> MACHINE conversion */

#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))

#define virt_to_mfn(v)		(pfn_to_mfn(PFN_DOWN(__pa(v))))

#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))

static inline unsigned long pte_mfn(pte_t pte)

{

	return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;

}

static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)

{

	pte_t pte;

	pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |

		(pgprot_val(pgprot) & __supported_pte_mask);

	return pte;

}

static inline pteval_t pte_val_ma(pte_t pte)

{

	return pte.pte;

}

static inline pte_t __pte_ma(pteval_t x)

{

	return (pte_t) { .pte = x };

}

#define pmd_val_ma(v) ((v).pmd)

#ifdef __PAGETABLE_PUD_FOLDED

#define pud_val_ma(v) ((v).pgd.pgd)

#else

#define pud_val_ma(v) ((v).pud)

#endif

#define __pmd_ma(x)	((pmd_t) { (x) } )

#define pgd_val_ma(x)	((x).pgd)

xmaddr_t arbitrary_virt_to_machine(void *address);

void make_lowmem_page_readonly(void *vaddr);

void make_lowmem_page_readwrite(void *vaddr);

#endif /* _ASM_X86_XEN_PAGE_H */