LXR linux/arch/x86/include/asm/xen/page.h

   1#ifndef _ASM_X86_XEN_PAGE_H
   2#define _ASM_X86_XEN_PAGE_H
   3
   4#include <linux/kernel.h>
   5#include <linux/types.h>
   6#include <linux/spinlock.h>
   7#include <linux/pfn.h>
   8
   9#include <asm/uaccess.h>
  10#include <asm/page.h>
  11#include <asm/pgtable.h>
  12
  13#include <xen/interface/xen.h>
  14#include <xen/features.h>
  15
  16/* Xen machine address */
  17typedef struct xmaddr {
  18        phys_addr_t maddr;
  19} xmaddr_t;
  20
  21/* Xen pseudo-physical address */
  22typedef struct xpaddr {
  23        phys_addr_t paddr;
  24} xpaddr_t;
  25
  26#define XMADDR(x)       ((xmaddr_t) { .maddr = (x) })
  27#define XPADDR(x)       ((xpaddr_t) { .paddr = (x) })
  28
  29/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
  30#define INVALID_P2M_ENTRY       (~0UL)
  31#define FOREIGN_FRAME_BIT       (1UL<<31)
  32#define FOREIGN_FRAME(m)        ((m) | FOREIGN_FRAME_BIT)
  33
  34/* Maximum amount of memory we can handle in a domain in pages */
  35#define MAX_DOMAIN_PAGES                                                \
  36    ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE))
  37
  38
  39extern unsigned long get_phys_to_machine(unsigned long pfn);
  40extern void set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  41
  42static inline unsigned long pfn_to_mfn(unsigned long pfn)
  43{
  44        if (xen_feature(XENFEAT_auto_translated_physmap))
  45                return pfn;
  46
  47        return get_phys_to_machine(pfn) & ~FOREIGN_FRAME_BIT;
  48}
  49
  50static inline int phys_to_machine_mapping_valid(unsigned long pfn)
  51{
  52        if (xen_feature(XENFEAT_auto_translated_physmap))
  53                return 1;
  54
  55        return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
  56}
  57
  58static inline unsigned long mfn_to_pfn(unsigned long mfn)
  59{
  60        unsigned long pfn;
  61
  62        if (xen_feature(XENFEAT_auto_translated_physmap))
  63                return mfn;
  64
  65#if 0
  66        if (unlikely((mfn >> machine_to_phys_order) != 0))
  67                return max_mapnr;
  68#endif
  69
  70        pfn = 0;
  71        /*
  72         * The array access can fail (e.g., device space beyond end of RAM).
  73         * In such cases it doesn't matter what we return (we return garbage),
  74         * but we must handle the fault without crashing!
  75         */
  76        __get_user(pfn, &machine_to_phys_mapping[mfn]);
  77
  78        return pfn;
  79}
  80
  81static inline xmaddr_t phys_to_machine(xpaddr_t phys)
  82{
  83        unsigned offset = phys.paddr & ~PAGE_MASK;
  84        return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
  85}
  86
  87static inline xpaddr_t machine_to_phys(xmaddr_t machine)
  88{
  89        unsigned offset = machine.maddr & ~PAGE_MASK;
  90        return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
  91}
  92
  93/*
  94 * We detect special mappings in one of two ways:
  95 *  1. If the MFN is an I/O page then Xen will set the m2p entry
  96 *     to be outside our maximum possible pseudophys range.
  97 *  2. If the MFN belongs to a different domain then we will certainly
  98 *     not have MFN in our p2m table. Conversely, if the page is ours,
  99 *     then we'll have p2m(m2p(MFN))==MFN.
 100 * If we detect a special mapping then it doesn't have a 'struct page'.
 101 * We force !pfn_valid() by returning an out-of-range pointer.
 102 *
 103 * NB. These checks require that, for any MFN that is not in our reservation,
 104 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 105 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 106 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 107 *
 108 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 109 *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 110 *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 111 *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 112 */
 113static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
 114{
 115        extern unsigned long max_mapnr;
 116        unsigned long pfn = mfn_to_pfn(mfn);
 117        if ((pfn < max_mapnr)
 118            && !xen_feature(XENFEAT_auto_translated_physmap)
 119            && (get_phys_to_machine(pfn) != mfn))
 120                return max_mapnr; /* force !pfn_valid() */
 121        /* XXX fixme; not true with sparsemem */
 122        return pfn;
 123}
 124
 125/* VIRT <-> MACHINE conversion */
 126#define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 127#define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 128#define virt_to_mfn(v)          (pfn_to_mfn(virt_to_pfn(v)))
 129#define mfn_to_virt(m)          (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 130
 131static inline unsigned long pte_mfn(pte_t pte)
 132{
 133        return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
 134}
 135
 136static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
 137{
 138        pte_t pte;
 139
 140        pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
 141                        massage_pgprot(pgprot);
 142
 143        return pte;
 144}
 145
 146static inline pteval_t pte_val_ma(pte_t pte)
 147{
 148        return pte.pte;
 149}
 150
 151static inline pte_t __pte_ma(pteval_t x)
 152{
 153        return (pte_t) { .pte = x };
 154}
 155
 156#define pmd_val_ma(v) ((v).pmd)
 157#ifdef __PAGETABLE_PUD_FOLDED
 158#define pud_val_ma(v) ((v).pgd.pgd)
 159#else
 160#define pud_val_ma(v) ((v).pud)
 161#endif
 162#define __pmd_ma(x)     ((pmd_t) { (x) } )
 163
 164#define pgd_val_ma(x)   ((x).pgd)
 165
 166
 167xmaddr_t arbitrary_virt_to_machine(void *address);
 168unsigned long arbitrary_virt_to_mfn(void *vaddr);
 169void make_lowmem_page_readonly(void *vaddr);
 170void make_lowmem_page_readwrite(void *vaddr);
 171
 172#endif /* _ASM_X86_XEN_PAGE_H */
 173