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 set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
  53                                    struct gnttab_map_grant_ref *kmap_ops,
  54                                    struct page **pages, unsigned int count);
  55 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
  56                                      struct gnttab_map_grant_ref *kmap_ops,
  57                                      struct page **pages, unsigned int count);
  58 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
  59
  60 static inline unsigned long pfn_to_mfn(unsigned long pfn)
  61 {
  62         unsigned long mfn;
  63
  64         if (xen_feature(XENFEAT_auto_translated_physmap))
  65                 return pfn;
  66
  67         mfn = get_phys_to_machine(pfn);
  68
  69         if (mfn != INVALID_P2M_ENTRY)
  70                 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
  71
  72         return mfn;
  73 }
  74
  75 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
  76 {
  77         if (xen_feature(XENFEAT_auto_translated_physmap))
  78                 return 1;
  79
  80         return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
  81 }
  82
  83 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
  84 {
  85         unsigned long pfn;
  86         int ret;
  87
  88         if (xen_feature(XENFEAT_auto_translated_physmap))
  89                 return mfn;
  90
  91         if (unlikely(mfn >= machine_to_phys_nr))
  92                 return ~0;
  93
  94         /*
  95          * The array access can fail (e.g., device space beyond end of RAM).
  96          * In such cases it doesn't matter what we return (we return garbage),
  97          * but we must handle the fault without crashing!
  98          */
  99         ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
 100         if (ret < 0)
 101                 return ~0;
 102
 103         return pfn;
 104 }
 105
 106 static inline unsigned long mfn_to_pfn(unsigned long mfn)
 107 {
 108         unsigned long pfn;
 109
 110         if (xen_feature(XENFEAT_auto_translated_physmap))
 111                 return mfn;
 112
 113         pfn = mfn_to_pfn_no_overrides(mfn);
 114         if (get_phys_to_machine(pfn) != mfn) {
 115                 /*
 116                  * If this appears to be a foreign mfn (because the pfn
 117                  * doesn't map back to the mfn), then check the local override
 118                  * table to see if there's a better pfn to use.
 119                  *
 120                  * m2p_find_override_pfn returns ~0 if it doesn't find anything.
 121                  */
 122                 pfn = m2p_find_override_pfn(mfn, ~0);
 123         }
 124
 125         /*
 126          * pfn is ~0 if there are no entries in the m2p for mfn or if the
 127          * entry doesn't map back to the mfn and m2p_override doesn't have a
 128          * valid entry for it.
 129          */
 130         if (pfn == ~0 &&
 131                         get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
 132                 pfn = mfn;
 133
 134         return pfn;
 135 }
 136
 137 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 138 {
 139         unsigned offset = phys.paddr & ~PAGE_MASK;
 140         return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
 141 }
 142
 143 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
 144 {
 145         unsigned offset = machine.maddr & ~PAGE_MASK;
 146         return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
 147 }
 148
 149 /*
 150  * We detect special mappings in one of two ways:
 151  *  1. If the MFN is an I/O page then Xen will set the m2p entry
 152  *     to be outside our maximum possible pseudophys range.
 153  *  2. If the MFN belongs to a different domain then we will certainly
 154  *     not have MFN in our p2m table. Conversely, if the page is ours,
 155  *     then we'll have p2m(m2p(MFN))==MFN.
 156  * If we detect a special mapping then it doesn't have a 'struct page'.
 157  * We force !pfn_valid() by returning an out-of-range pointer.
 158  *
 159  * NB. These checks require that, for any MFN that is not in our reservation,
 160  * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 161  * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 162  * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 163  *
 164  * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 165  *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 166  *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 167  *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 168  */
 169 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
 170 {
 171         unsigned long pfn;
 172
 173         if (xen_feature(XENFEAT_auto_translated_physmap))
 174                 return mfn;
 175
 176         pfn = mfn_to_pfn(mfn);
 177         if (get_phys_to_machine(pfn) != mfn)
 178                 return -1; /* force !pfn_valid() */
 179         return pfn;
 180 }
 181
 182 /* VIRT <-> MACHINE conversion */
 183 #define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 184 #define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 185 #define virt_to_mfn(v)          (pfn_to_mfn(virt_to_pfn(v)))
 186 #define mfn_to_virt(m)          (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 187
 188 static inline unsigned long pte_mfn(pte_t pte)
 189 {
 190         return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
 191 }
 192
 193 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
 194 {
 195         pte_t pte;
 196
 197         pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
 198                         massage_pgprot(pgprot);
 199
 200         return pte;
 201 }
 202
 203 static inline pteval_t pte_val_ma(pte_t pte)
 204 {
 205         return pte.pte;
 206 }
 207
 208 static inline pte_t __pte_ma(pteval_t x)
 209 {
 210         return (pte_t) { .pte = x };
 211 }
 212
 213 #define pmd_val_ma(v) ((v).pmd)
 214 #ifdef __PAGETABLE_PUD_FOLDED
 215 #define pud_val_ma(v) ((v).pgd.pgd)
 216 #else
 217 #define pud_val_ma(v) ((v).pud)
 218 #endif
 219 #define __pmd_ma(x)     ((pmd_t) { (x) } )
 220
 221 #define pgd_val_ma(x)   ((x).pgd)
 222
 223 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
 224
 225 xmaddr_t arbitrary_virt_to_machine(void *address);
 226 unsigned long arbitrary_virt_to_mfn(void *vaddr);
 227 void make_lowmem_page_readonly(void *vaddr);
 228 void make_lowmem_page_readwrite(void *vaddr);
 229
 230 #define xen_remap(cookie, size) ioremap((cookie), (size));
 231 #define xen_unmap(cookie) iounmap((cookie))
 232
 233 static inline bool xen_arch_need_swiotlb(struct device *dev,
 234                                          unsigned long pfn,
 235                                          unsigned long mfn)
 236 {
 237         return false;
 238 }
 239
 240 #endif /* _ASM_X86_XEN_PAGE_H */