#ifndef _X86_64_PAGE_H
#define _X86_64_PAGE_H

#include <linux/config.h>
/* #include <linux/string.h> */
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <linux/types.h>
#include <asm/bug.h>
#include <xen/features.h>
#endif
#include <xen/interface/xen.h> 
#include <xen/foreign_page.h>

#define arch_free_page(_page,_order)			\
({	int foreign = PageForeign(_page);		\
	if (foreign)					\
		(PageForeignDestructor(_page))(_page);	\
	foreign;					\
})
#define HAVE_ARCH_FREE_PAGE

#ifdef CONFIG_XEN_SCRUB_PAGES
#define scrub_pages(_p,_n) memset((void *)(_p), 0, (_n) << PAGE_SHIFT)
#else
#define scrub_pages(_p,_n) ((void)0)
#endif

/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT	12
#ifdef __ASSEMBLY__
#define PAGE_SIZE	(0x1 << PAGE_SHIFT)
#else
#define PAGE_SIZE	(1UL << PAGE_SHIFT)
#endif
#define PAGE_MASK	(~(PAGE_SIZE-1))
#define PHYSICAL_PAGE_MASK	(~(PAGE_SIZE-1) & __PHYSICAL_MASK)

#define THREAD_ORDER 1 
#define THREAD_SIZE  (PAGE_SIZE << THREAD_ORDER)
#define CURRENT_MASK (~(THREAD_SIZE-1))

#define EXCEPTION_STACK_ORDER 0
#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)

#define DEBUG_STACK_ORDER EXCEPTION_STACK_ORDER
#define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER)

#define IRQSTACK_ORDER 2
#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)

#define STACKFAULT_STACK 1
#define DOUBLEFAULT_STACK 2
#define NMI_STACK 3
#define DEBUG_STACK 4
#define MCE_STACK 5
#define N_EXCEPTION_STACKS 5  /* hw limit: 7 */

#define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))
#define LARGE_PAGE_SIZE (1UL << PMD_SHIFT)

#define HPAGE_SHIFT PMD_SHIFT
#define HPAGE_SIZE	((1UL) << HPAGE_SHIFT)
#define HPAGE_MASK	(~(HPAGE_SIZE - 1))
#define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)

#ifdef __KERNEL__
#ifndef __ASSEMBLY__

extern unsigned long end_pfn;

void clear_page(void *);
void copy_page(void *, void *);

#define clear_user_page(page, vaddr, pg)	clear_page(page)
#define copy_user_page(to, from, vaddr, pg)	copy_page(to, from)

#define alloc_zeroed_user_highpage(vma, vaddr) alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vma, vaddr)
#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE

/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
#define INVALID_P2M_ENTRY	(~0UL)
#define FOREIGN_FRAME_BIT	(1UL<<63)
#define FOREIGN_FRAME(m)	((m) | FOREIGN_FRAME_BIT)

extern unsigned long *phys_to_machine_mapping;

#undef machine_to_phys_mapping
extern unsigned long *machine_to_phys_mapping;
extern unsigned int   machine_to_phys_order;

static inline unsigned long pfn_to_mfn(unsigned long pfn)
{
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return pfn;
	return phys_to_machine_mapping[(unsigned int)(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 (phys_to_machine_mapping[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 (unlikely((mfn >> machine_to_phys_order) != 0))
		return end_pfn;

	/* The array access can fail (e.g., device space beyond end of RAM). */
	asm (
		"1:	movq %1,%0\n"
		"2:\n"
		".section .fixup,\"ax\"\n"
		"3:	movq %2,%0\n"
		"	jmp  2b\n"
		".previous\n"
		".section __ex_table,\"a\"\n"
		"	.align 8\n"
		"	.quad 1b,3b\n"
		".previous"
		: "=r" (pfn)
		: "m" (machine_to_phys_mapping[mfn]), "m" (end_pfn) );

	return pfn;
}

/*
 * 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)
{
	unsigned long pfn = mfn_to_pfn(mfn);
	if ((pfn < end_pfn)
	    && !xen_feature(XENFEAT_auto_translated_physmap)
	    && (phys_to_machine_mapping[pfn] != mfn))
		return end_pfn; /* force !pfn_valid() */
	return pfn;
}


static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
{
	if (xen_feature(XENFEAT_auto_translated_physmap)) {
		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
		return;
	}
	phys_to_machine_mapping[pfn] = mfn;
}

/* Definitions for machine and pseudophysical addresses. */
typedef unsigned long paddr_t;
typedef unsigned long maddr_t;

static inline maddr_t phys_to_machine(paddr_t phys)
{
	maddr_t machine = pfn_to_mfn(phys >> PAGE_SHIFT);
	machine = (machine << PAGE_SHIFT) | (phys & ~PAGE_MASK);
	return machine;
}

static inline paddr_t machine_to_phys(maddr_t machine)
{
	paddr_t phys = mfn_to_pfn(machine >> PAGE_SHIFT);
	phys = (phys << PAGE_SHIFT) | (machine & ~PAGE_MASK);
	return phys;
}

/*
 * These are used to make use of C type-checking..
 */
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pud; } pud_t;
typedef struct { unsigned long pgd; } pgd_t;
#define PTE_MASK	PHYSICAL_PAGE_MASK

typedef struct { unsigned long pgprot; } pgprot_t;

#define pte_val(x)	(((x).pte & 1) ? machine_to_phys((x).pte) : \
			 (x).pte)
#define pte_val_ma(x)	((x).pte)

static inline unsigned long pmd_val(pmd_t x)
{
	unsigned long ret = x.pmd;
	if (ret) ret = machine_to_phys(ret);
	return ret;
}

static inline unsigned long pud_val(pud_t x)
{
	unsigned long ret = x.pud;
	if (ret) ret = machine_to_phys(ret);
	return ret;
}

static inline unsigned long pgd_val(pgd_t x)
{
	unsigned long ret = x.pgd;
	if (ret) ret = machine_to_phys(ret);
	return ret;
}

#define pgprot_val(x)	((x).pgprot)

#define __pte_ma(x)     ((pte_t) { (x) } )

static inline pte_t __pte(unsigned long x)
{
	if (x & 1) x = phys_to_machine(x);
	return ((pte_t) { (x) });
}

static inline pmd_t __pmd(unsigned long x)
{
	if ((x & 1)) x = phys_to_machine(x);
	return ((pmd_t) { (x) });
}

static inline pud_t __pud(unsigned long x)
{
	if ((x & 1)) x = phys_to_machine(x);
	return ((pud_t) { (x) });
}

static inline pgd_t __pgd(unsigned long x)
{
	if ((x & 1)) x = phys_to_machine(x);
	return ((pgd_t) { (x) });
}

#define __pgprot(x)	((pgprot_t) { (x) } )

#define __PHYSICAL_START	((unsigned long)CONFIG_PHYSICAL_START)
#define __START_KERNEL		(__START_KERNEL_map + __PHYSICAL_START)
#define __START_KERNEL_map	0xffffffff80000000UL
#define __PAGE_OFFSET           0xffff880000000000UL	

#else
#define __PHYSICAL_START	CONFIG_PHYSICAL_START
#define __START_KERNEL		(__START_KERNEL_map + __PHYSICAL_START)
#define __START_KERNEL_map	0xffffffff80000000
#define __PAGE_OFFSET           0xffff880000000000
#endif /* !__ASSEMBLY__ */

#ifdef CONFIG_XEN_COMPAT_030002
#undef LOAD_OFFSET
#define LOAD_OFFSET		0
#endif /* CONFIG_XEN_COMPAT_030002 */

/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr)	(((addr)+PAGE_SIZE-1)&PAGE_MASK)

/* See Documentation/x86_64/mm.txt for a description of the memory map. */
#define __PHYSICAL_MASK_SHIFT	46
#define __PHYSICAL_MASK		((1UL << __PHYSICAL_MASK_SHIFT) - 1)
#define __VIRTUAL_MASK_SHIFT	48
#define __VIRTUAL_MASK		((1UL << __VIRTUAL_MASK_SHIFT) - 1)

#define KERNEL_TEXT_SIZE  (40UL*1024*1024)
#define KERNEL_TEXT_START 0xffffffff80000000UL 

#define PAGE_OFFSET		((unsigned long)__PAGE_OFFSET)

/* Note: __pa(&symbol_visible_to_c) should be always replaced with __pa_symbol.
   Otherwise you risk miscompilation. */ 
#define __pa(x)			(((unsigned long)(x)>=__START_KERNEL_map)?(unsigned long)(x) - (unsigned long)__START_KERNEL_map:(unsigned long)(x) - PAGE_OFFSET)
/* __pa_symbol should be used for C visible symbols.
   This seems to be the official gcc blessed way to do such arithmetic. */ 
#define __pa_symbol(x)		\
	({unsigned long v;  \
	  asm("" : "=r" (v) : "0" (x)); \
	  __pa(v); })

#define __va(x)			((void *)((unsigned long)(x)+PAGE_OFFSET))
#define __boot_va(x)		__va(x)
#define __boot_pa(x)		__pa(x)
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn)		((pfn) < end_pfn)
#endif

#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_kaddr(pfn)      __va((pfn) << PAGE_SHIFT)

/* VIRT <-> MACHINE conversion */
#define virt_to_machine(v)	(phys_to_machine(__pa(v)))
#define virt_to_mfn(v)		(pfn_to_mfn(__pa(v) >> PAGE_SHIFT))
#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))

#define VM_DATA_DEFAULT_FLAGS \
	(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
	 VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)

#define __HAVE_ARCH_GATE_AREA 1	

#ifndef __ASSEMBLY__
extern int devmem_is_allowed(unsigned long pagenr);
#endif

#endif /* __KERNEL__ */

#include <asm-generic/memory_model.h>
#include <asm-generic/page.h>

#endif /* _X86_64_PAGE_H */