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 #include <linux/mm.h>
   9
  10 #include <asm/uaccess.h>
  11 #include <asm/page.h>
  12 #include <asm/pgtable.h>
  13
  14 #include <xen/interface/xen.h>
  15 #include <xen/grant_table.h>
  16 #include <xen/features.h>
  17
  18 /* Xen machine address */
  19 typedef struct xmaddr {
  20         phys_addr_t maddr;
  21 } xmaddr_t;
  22
  23 /* Xen pseudo-physical address */
  24 typedef struct xpaddr {
  25         phys_addr_t paddr;
  26 } xpaddr_t;
  27
  28 #define XMADDR(x)       ((xmaddr_t) { .maddr = (x) })
  29 #define XPADDR(x)       ((xpaddr_t) { .paddr = (x) })
  30
  31 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
  32 #define INVALID_P2M_ENTRY       (~0UL)
  33 #define FOREIGN_FRAME_BIT       (1UL<<(BITS_PER_LONG-1))
  34 #define IDENTITY_FRAME_BIT      (1UL<<(BITS_PER_LONG-2))
  35 #define FOREIGN_FRAME(m)        ((m) | FOREIGN_FRAME_BIT)
  36 #define IDENTITY_FRAME(m)       ((m) | IDENTITY_FRAME_BIT)
  37
  38 /* Maximum amount of memory we can handle in a domain in pages */
  39 #define MAX_DOMAIN_PAGES                                                \
  40     ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE))
  41
  42 extern unsigned long *machine_to_phys_mapping;
  43 extern unsigned long  machine_to_phys_nr;
  44
  45 extern unsigned long get_phys_to_machine(unsigned long pfn);
  46 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  47 extern bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  48 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  49 extern unsigned long set_phys_range_identity(unsigned long pfn_s,
  50                                              unsigned long pfn_e);
  51
  52 extern int m2p_add_override(unsigned long mfn, struct page *page,
  53                             struct gnttab_map_grant_ref *kmap_op);
  54 extern int m2p_remove_override(struct page *page,
  55                                 struct gnttab_map_grant_ref *kmap_op);
  56 extern struct page *m2p_find_override(unsigned long mfn);
  57 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
  58
  59 static inline unsigned long pfn_to_mfn(unsigned long pfn)
  60 {
  61         unsigned long mfn;
  62
  63         if (xen_feature(XENFEAT_auto_translated_physmap))
  64                 return pfn;
  65
  66         mfn = get_phys_to_machine(pfn);
  67
  68         if (mfn != INVALID_P2M_ENTRY)
  69                 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
  70
  71         return mfn;
  72 }
  73
  74 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
  75 {
  76         if (xen_feature(XENFEAT_auto_translated_physmap))
  77                 return 1;
  78
  79         return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
  80 }
  81
  82 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
  83 {
  84         unsigned long pfn;
  85         int ret;
  86
  87         if (xen_feature(XENFEAT_auto_translated_physmap))
  88                 return mfn;
  89
  90         if (unlikely(mfn >= machine_to_phys_nr))
  91                 return ~0;
  92
  93         /*
  94          * The array access can fail (e.g., device space beyond end of RAM).
  95          * In such cases it doesn't matter what we return (we return garbage),
  96          * but we must handle the fault without crashing!
  97          */
  98         ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
  99         if (ret < 0)
 100                 return ~0;
 101
 102         return pfn;
 103 }
 104
 105 static inline unsigned long mfn_to_pfn(unsigned long mfn)
 106 {
 107         unsigned long pfn;
 108
 109         if (xen_feature(XENFEAT_auto_translated_physmap))
 110                 return mfn;
 111
 112         pfn = mfn_to_pfn_no_overrides(mfn);
 113         if (get_phys_to_machine(pfn) != mfn) {
 114                 /*
 115                  * If this appears to be a foreign mfn (because the pfn
 116                  * doesn't map back to the mfn), then check the local override
 117                  * table to see if there's a better pfn to use.
 118                  *
 119                  * m2p_find_override_pfn returns ~0 if it doesn't find anything.
 120                  */
 121                 pfn = m2p_find_override_pfn(mfn, ~0);
 122         }
 123
 124         /*
 125          * pfn is ~0 if there are no entries in the m2p for mfn or if the
 126          * entry doesn't map back to the mfn and m2p_override doesn't have a
 127          * valid entry for it.
 128          */
 129         if (pfn == ~0 &&
 130                         get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
 131                 pfn = mfn;
 132
 133         return pfn;
 134 }
 135
 136 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 137 {
 138         unsigned offset = phys.paddr & ~PAGE_MASK;
 139         return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
 140 }
 141
 142 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
 143 {
 144         unsigned offset = machine.maddr & ~PAGE_MASK;
 145         return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
 146 }
 147
 148 /*
 149  * We detect special mappings in one of two ways:
 150  *  1. If the MFN is an I/O page then Xen will set the m2p entry
 151  *     to be outside our maximum possible pseudophys range.
 152  *  2. If the MFN belongs to a different domain then we will certainly
 153  *     not have MFN in our p2m table. Conversely, if the page is ours,
 154  *     then we'll have p2m(m2p(MFN))==MFN.
 155  * If we detect a special mapping then it doesn't have a 'struct page'.
 156  * We force !pfn_valid() by returning an out-of-range pointer.
 157  *
 158  * NB. These checks require that, for any MFN that is not in our reservation,
 159  * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 160  * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 161  * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 162  *
 163  * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 164  *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 165  *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 166  *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 167  */
 168 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
 169 {
 170         unsigned long pfn = mfn_to_pfn(mfn);
 171         if (get_phys_to_machine(pfn) != mfn)
 172                 return -1; /* force !pfn_valid() */
 173         return pfn;
 174 }
 175
 176 /* VIRT <-> MACHINE conversion */
 177 #define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 178 #define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 179 #define virt_to_mfn(v)          (pfn_to_mfn(virt_to_pfn(v)))
 180 #define mfn_to_virt(m)          (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 181
 182 static inline unsigned long pte_mfn(pte_t pte)
 183 {
 184         return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
 185 }
 186
 187 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
 188 {
 189         pte_t pte;
 190
 191         pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
 192                         massage_pgprot(pgprot);
 193
 194         return pte;
 195 }
 196
 197 static inline pteval_t pte_val_ma(pte_t pte)
 198 {
 199         return pte.pte;
 200 }
 201
 202 static inline pte_t __pte_ma(pteval_t x)
 203 {
 204         return (pte_t) { .pte = x };
 205 }
 206
 207 #define pmd_val_ma(v) ((v).pmd)
 208 #ifdef __PAGETABLE_PUD_FOLDED
 209 #define pud_val_ma(v) ((v).pgd.pgd)
 210 #else
 211 #define pud_val_ma(v) ((v).pud)
 212 #endif
 213 #define __pmd_ma(x)     ((pmd_t) { (x) } )
 214
 215 #define pgd_val_ma(x)   ((x).pgd)
 216
 217 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
 218
 219 xmaddr_t arbitrary_virt_to_machine(void *address);
 220 unsigned long arbitrary_virt_to_mfn(void *vaddr);
 221 void make_lowmem_page_readonly(void *vaddr);
 222 void make_lowmem_page_readwrite(void *vaddr);
 223
 224 #define xen_remap(cookie, size) ioremap((cookie), (size));
 225
 226 #endif /* _ASM_X86_XEN_PAGE_H */