arch/x86/include/asm/xen/page.h - kernel/lockdown - Git at Google

 #ifndef _ASM_X86_XEN_PAGE_H
 #define _ASM_X86_XEN_PAGE_H

 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/spinlock.h>
 #include <linux/pfn.h>
 #include <linux/mm.h>

 #include <asm/uaccess.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>

 #include <xen/interface/xen.h>
 #include <xen/grant_table.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<<(BITS_PER_LONG-1))
 #define IDENTITY_FRAME_BIT	(1UL<<(BITS_PER_LONG-2))
 #define FOREIGN_FRAME(m)	((m) | FOREIGN_FRAME_BIT)
 #define IDENTITY_FRAME(m)	((m) | IDENTITY_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 *machine_to_phys_mapping;
 extern unsigned long  machine_to_phys_nr;

 extern unsigned long get_phys_to_machine(unsigned long pfn);
 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 extern bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 extern unsigned long set_phys_range_identity(unsigned long pfn_s,
 					     unsigned long pfn_e);

 extern int m2p_add_override(unsigned long mfn, struct page *page,
 			    struct gnttab_map_grant_ref *kmap_op);
 extern int m2p_remove_override(struct page *page,
 				struct gnttab_map_grant_ref *kmap_op);
 extern struct page *m2p_find_override(unsigned long mfn);
 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);

 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 {
 	unsigned long mfn;

 	if (xen_feature(XENFEAT_auto_translated_physmap))
 		return pfn;

 	mfn = get_phys_to_machine(pfn);

 	if (mfn != INVALID_P2M_ENTRY)
 		mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);

 	return mfn;
 }

 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_no_overrides(unsigned long mfn)
 {
 	unsigned long pfn;
 	int ret;

 	if (xen_feature(XENFEAT_auto_translated_physmap))
 		return mfn;

 	if (unlikely(mfn >= machine_to_phys_nr))
 		return ~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!
 	 */
 	ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
 	if (ret < 0)
 		return ~0;

 	return pfn;
 }

 static inline unsigned long mfn_to_pfn(unsigned long mfn)
 {
 	unsigned long pfn;

 	if (xen_feature(XENFEAT_auto_translated_physmap))
 		return mfn;

 	pfn = mfn_to_pfn_no_overrides(mfn);
 	if (get_phys_to_machine(pfn) != mfn) {
 		/*
 		 * If this appears to be a foreign mfn (because the pfn
 		 * doesn't map back to the mfn), then check the local override
 		 * table to see if there's a better pfn to use.
 		 *
 		 * m2p_find_override_pfn returns ~0 if it doesn't find anything.
 		 */
 		pfn = m2p_find_override_pfn(mfn, ~0);
 	}

 	/*
 	 * pfn is ~0 if there are no entries in the m2p for mfn or if the
 	 * entry doesn't map back to the mfn and m2p_override doesn't have a
 	 * valid entry for it.
 	 */
 	if (pfn == ~0 &&
 			get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
 		pfn = 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)
 {
 	unsigned long pfn;

 	if (xen_feature(XENFEAT_auto_translated_physmap))
 		return mfn;

 	pfn = mfn_to_pfn(mfn);
 	if (get_phys_to_machine(pfn) != mfn)
 		return -1; /* force !pfn_valid() */
 	return pfn;
 }

 /* VIRT <-> MACHINE conversion */
 #define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
 #define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 #define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(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) |
 			massage_pgprot(pgprot);

 	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)

 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);

 xmaddr_t arbitrary_virt_to_machine(void *address);
 unsigned long arbitrary_virt_to_mfn(void *vaddr);
 void make_lowmem_page_readonly(void *vaddr);
 void make_lowmem_page_readwrite(void *vaddr);

 #define xen_remap(cookie, size) ioremap((cookie), (size));
 #define xen_unmap(cookie) iounmap((cookie))

 #endif /* _ASM_X86_XEN_PAGE_H */
	#ifndef _ASM_X86_XEN_PAGE_H
	#define _ASM_X86_XEN_PAGE_H

	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/spinlock.h>
	#include <linux/pfn.h>
	#include <linux/mm.h>

	#include <asm/uaccess.h>
	#include <asm/page.h>
	#include <asm/pgtable.h>

	#include <xen/interface/xen.h>
	#include <xen/grant_table.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<<(BITS_PER_LONG-1))
	#define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2))
	#define FOREIGN_FRAME(m) ((m) \| FOREIGN_FRAME_BIT)
	#define IDENTITY_FRAME(m) ((m) \| IDENTITY_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 *machine_to_phys_mapping;
	extern unsigned long machine_to_phys_nr;

	extern unsigned long get_phys_to_machine(unsigned long pfn);
	extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
	extern bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn);
	extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
	extern unsigned long set_phys_range_identity(unsigned long pfn_s,
	unsigned long pfn_e);

	extern int m2p_add_override(unsigned long mfn, struct page *page,
	struct gnttab_map_grant_ref *kmap_op);
	extern int m2p_remove_override(struct page *page,
	struct gnttab_map_grant_ref *kmap_op);
	extern struct page *m2p_find_override(unsigned long mfn);
	extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);

	static inline unsigned long pfn_to_mfn(unsigned long pfn)
	{
	unsigned long mfn;

	if (xen_feature(XENFEAT_auto_translated_physmap))
	return pfn;

	mfn = get_phys_to_machine(pfn);

	if (mfn != INVALID_P2M_ENTRY)
	mfn &= ~(FOREIGN_FRAME_BIT \| IDENTITY_FRAME_BIT);

	return mfn;
	}

	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_no_overrides(unsigned long mfn)
	{
	unsigned long pfn;
	int ret;

	if (xen_feature(XENFEAT_auto_translated_physmap))
	return mfn;

	if (unlikely(mfn >= machine_to_phys_nr))
	return ~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!
	*/
	ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
	if (ret < 0)
	return ~0;

	return pfn;
	}

	static inline unsigned long mfn_to_pfn(unsigned long mfn)
	{
	unsigned long pfn;

	if (xen_feature(XENFEAT_auto_translated_physmap))
	return mfn;

	pfn = mfn_to_pfn_no_overrides(mfn);
	if (get_phys_to_machine(pfn) != mfn) {
	/*
	* If this appears to be a foreign mfn (because the pfn
	* doesn't map back to the mfn), then check the local override
	* table to see if there's a better pfn to use.
	*
	* m2p_find_override_pfn returns ~0 if it doesn't find anything.
	*/
	pfn = m2p_find_override_pfn(mfn, ~0);
	}

	/*
	* pfn is ~0 if there are no entries in the m2p for mfn or if the
	* entry doesn't map back to the mfn and m2p_override doesn't have a
	* valid entry for it.
	*/
	if (pfn == ~0 &&
	get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
	pfn = 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)
	{
	unsigned long pfn;

	if (xen_feature(XENFEAT_auto_translated_physmap))
	return mfn;

	pfn = mfn_to_pfn(mfn);
	if (get_phys_to_machine(pfn) != mfn)
	return -1; /* force !pfn_valid() */
	return pfn;
	}

	/* VIRT <-> MACHINE conversion */
	#define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
	#define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
	#define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(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) \|
	massage_pgprot(pgprot);

	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)

	void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);

	xmaddr_t arbitrary_virt_to_machine(void *address);
	unsigned long arbitrary_virt_to_mfn(void *vaddr);
	void make_lowmem_page_readonly(void *vaddr);
	void make_lowmem_page_readwrite(void *vaddr);

	#define xen_remap(cookie, size) ioremap((cookie), (size));
	#define xen_unmap(cookie) iounmap((cookie))

	#endif /* _ASM_X86_XEN_PAGE_H */