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 #include <linux/device.h>
  10
  11 #include <linux/uaccess.h>
  12 #include <asm/page.h>
  13 #include <asm/pgtable.h>
  14
  15 #include <xen/interface/xen.h>
  16 #include <xen/interface/grant_table.h>
  17 #include <xen/features.h>
  18
  19 /* Xen machine address */
  20 typedef struct xmaddr {
  21         phys_addr_t maddr;
  22 } xmaddr_t;
  23
  24 /* Xen pseudo-physical address */
  25 typedef struct xpaddr {
  26         phys_addr_t paddr;
  27 } xpaddr_t;
  28
  29 #define XMADDR(x)       ((xmaddr_t) { .maddr = (x) })
  30 #define XPADDR(x)       ((xpaddr_t) { .paddr = (x) })
  31
  32 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
  33 #define INVALID_P2M_ENTRY       (~0UL)
  34 #define FOREIGN_FRAME_BIT       (1UL<<(BITS_PER_LONG-1))
  35 #define IDENTITY_FRAME_BIT      (1UL<<(BITS_PER_LONG-2))
  36 #define FOREIGN_FRAME(m)        ((m) | FOREIGN_FRAME_BIT)
  37 #define IDENTITY_FRAME(m)       ((m) | IDENTITY_FRAME_BIT)
  38
  39 #define P2M_PER_PAGE            (PAGE_SIZE / sizeof(unsigned long))
  40
  41 extern unsigned long *machine_to_phys_mapping;
  42 extern unsigned long  machine_to_phys_nr;
  43 extern unsigned long *xen_p2m_addr;
  44 extern unsigned long  xen_p2m_size;
  45 extern unsigned long  xen_max_p2m_pfn;
  46
  47 extern int xen_alloc_p2m_entry(unsigned long pfn);
  48
  49 extern unsigned long get_phys_to_machine(unsigned long pfn);
  50 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  51 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  52 extern unsigned long __init set_phys_range_identity(unsigned long pfn_s,
  53                                                     unsigned long pfn_e);
  54
  55 #ifdef CONFIG_XEN_PV
  56 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
  57                                    struct gnttab_map_grant_ref *kmap_ops,
  58                                    struct page **pages, unsigned int count);
  59 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
  60                                      struct gnttab_unmap_grant_ref *kunmap_ops,
  61                                      struct page **pages, unsigned int count);
  62 #else
  63 static inline int
  64 set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
  65                         struct gnttab_map_grant_ref *kmap_ops,
  66                         struct page **pages, unsigned int count)
  67 {
  68         return 0;
  69 }
  70
  71 static inline int
  72 clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
  73                           struct gnttab_unmap_grant_ref *kunmap_ops,
  74                           struct page **pages, unsigned int count)
  75 {
  76         return 0;
  77 }
  78 #endif
  79
  80 /*
  81  * Helper functions to write or read unsigned long values to/from
  82  * memory, when the access may fault.
  83  */
  84 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
  85 {
  86         return __put_user(val, (unsigned long __user *)addr);
  87 }
  88
  89 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val)
  90 {
  91         return __get_user(*val, (unsigned long __user *)addr);
  92 }
  93
  94 #ifdef CONFIG_XEN_PV
  95 /*
  96  * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
  97  * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
  98  *   bits (identity or foreign) are set.
  99  * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
 100  *   identity or foreign indicator will be still set. __pfn_to_mfn() is
 101  *   encapsulating get_phys_to_machine() which is called in special cases only.
 102  * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
 103  *   cases needing an extended handling.
 104  */
 105 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 106 {
 107         unsigned long mfn;
 108
 109         if (pfn < xen_p2m_size)
 110                 mfn = xen_p2m_addr[pfn];
 111         else if (unlikely(pfn < xen_max_p2m_pfn))
 112                 return get_phys_to_machine(pfn);
 113         else
 114                 return IDENTITY_FRAME(pfn);
 115
 116         if (unlikely(mfn == INVALID_P2M_ENTRY))
 117                 return get_phys_to_machine(pfn);
 118
 119         return mfn;
 120 }
 121 #else
 122 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 123 {
 124         return pfn;
 125 }
 126 #endif
 127
 128 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 129 {
 130         unsigned long mfn;
 131
 132         /*
 133          * Some x86 code are still using pfn_to_mfn instead of
 134          * pfn_to_mfn. This will have to be removed when we figured
 135          * out which call.
 136          */
 137         if (xen_feature(XENFEAT_auto_translated_physmap))
 138                 return pfn;
 139
 140         mfn = __pfn_to_mfn(pfn);
 141
 142         if (mfn != INVALID_P2M_ENTRY)
 143                 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
 144
 145         return mfn;
 146 }
 147
 148 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
 149 {
 150         if (xen_feature(XENFEAT_auto_translated_physmap))
 151                 return 1;
 152
 153         return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
 154 }
 155
 156 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
 157 {
 158         unsigned long pfn;
 159         int ret;
 160
 161         if (unlikely(mfn >= machine_to_phys_nr))
 162                 return ~0;
 163
 164         /*
 165          * The array access can fail (e.g., device space beyond end of RAM).
 166          * In such cases it doesn't matter what we return (we return garbage),
 167          * but we must handle the fault without crashing!
 168          */
 169         ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
 170         if (ret < 0)
 171                 return ~0;
 172
 173         return pfn;
 174 }
 175
 176 static inline unsigned long mfn_to_pfn(unsigned long mfn)
 177 {
 178         unsigned long pfn;
 179
 180         /*
 181          * Some x86 code are still using mfn_to_pfn instead of
 182          * gfn_to_pfn. This will have to be removed when we figure
 183          * out which call.
 184          */
 185         if (xen_feature(XENFEAT_auto_translated_physmap))
 186                 return mfn;
 187
 188         pfn = mfn_to_pfn_no_overrides(mfn);
 189         if (__pfn_to_mfn(pfn) != mfn)
 190                 pfn = ~0;
 191
 192         /*
 193          * pfn is ~0 if there are no entries in the m2p for mfn or the
 194          * entry doesn't map back to the mfn.
 195          */
 196         if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
 197                 pfn = mfn;
 198
 199         return pfn;
 200 }
 201
 202 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 203 {
 204         unsigned offset = phys.paddr & ~PAGE_MASK;
 205         return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
 206 }
 207
 208 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
 209 {
 210         unsigned offset = machine.maddr & ~PAGE_MASK;
 211         return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
 212 }
 213
 214 /* Pseudo-physical <-> Guest conversion */
 215 static inline unsigned long pfn_to_gfn(unsigned long pfn)
 216 {
 217         if (xen_feature(XENFEAT_auto_translated_physmap))
 218                 return pfn;
 219         else
 220                 return pfn_to_mfn(pfn);
 221 }
 222
 223 static inline unsigned long gfn_to_pfn(unsigned long gfn)
 224 {
 225         if (xen_feature(XENFEAT_auto_translated_physmap))
 226                 return gfn;
 227         else
 228                 return mfn_to_pfn(gfn);
 229 }
 230
 231 /* Pseudo-physical <-> Bus conversion */
 232 #define pfn_to_bfn(pfn)         pfn_to_gfn(pfn)
 233 #define bfn_to_pfn(bfn)         gfn_to_pfn(bfn)
 234
 235 /*
 236  * We detect special mappings in one of two ways:
 237  *  1. If the MFN is an I/O page then Xen will set the m2p entry
 238  *     to be outside our maximum possible pseudophys range.
 239  *  2. If the MFN belongs to a different domain then we will certainly
 240  *     not have MFN in our p2m table. Conversely, if the page is ours,
 241  *     then we'll have p2m(m2p(MFN))==MFN.
 242  * If we detect a special mapping then it doesn't have a 'struct page'.
 243  * We force !pfn_valid() by returning an out-of-range pointer.
 244  *
 245  * NB. These checks require that, for any MFN that is not in our reservation,
 246  * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 247  * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 248  * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 249  *
 250  * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 251  *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 252  *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 253  *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 254  */
 255 static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
 256 {
 257         unsigned long pfn;
 258
 259         if (xen_feature(XENFEAT_auto_translated_physmap))
 260                 return mfn;
 261
 262         pfn = mfn_to_pfn(mfn);
 263         if (__pfn_to_mfn(pfn) != mfn)
 264                 return -1; /* force !pfn_valid() */
 265         return pfn;
 266 }
 267
 268 /* VIRT <-> MACHINE conversion */
 269 #define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 270 #define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 271 #define virt_to_mfn(v)          (pfn_to_mfn(virt_to_pfn(v)))
 272 #define mfn_to_virt(m)          (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 273
 274 /* VIRT <-> GUEST conversion */
 275 #define virt_to_gfn(v)          (pfn_to_gfn(virt_to_pfn(v)))
 276 #define gfn_to_virt(g)          (__va(gfn_to_pfn(g) << PAGE_SHIFT))
 277
 278 static inline unsigned long pte_mfn(pte_t pte)
 279 {
 280         return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
 281 }
 282
 283 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
 284 {
 285         pte_t pte;
 286
 287         pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
 288                         massage_pgprot(pgprot);
 289
 290         return pte;
 291 }
 292
 293 static inline pteval_t pte_val_ma(pte_t pte)
 294 {
 295         return pte.pte;
 296 }
 297
 298 static inline pte_t __pte_ma(pteval_t x)
 299 {
 300         return (pte_t) { .pte = x };
 301 }
 302
 303 #define pmd_val_ma(v) ((v).pmd)
 304 #ifdef __PAGETABLE_PUD_FOLDED
 305 #define pud_val_ma(v) ((v).p4d.pgd.pgd)
 306 #else
 307 #define pud_val_ma(v) ((v).pud)
 308 #endif
 309 #define __pmd_ma(x)     ((pmd_t) { (x) } )
 310
 311 #ifdef __PAGETABLE_P4D_FOLDED
 312 #define p4d_val_ma(x)   ((x).pgd.pgd)
 313 #else
 314 #define p4d_val_ma(x)   ((x).p4d)
 315 #endif
 316
 317 xmaddr_t arbitrary_virt_to_machine(void *address);
 318 unsigned long arbitrary_virt_to_mfn(void *vaddr);
 319 void make_lowmem_page_readonly(void *vaddr);
 320 void make_lowmem_page_readwrite(void *vaddr);
 321
 322 #define xen_remap(cookie, size) ioremap((cookie), (size));
 323 #define xen_unmap(cookie) iounmap((cookie))
 324
 325 static inline bool xen_arch_need_swiotlb(struct device *dev,
 326                                          phys_addr_t phys,
 327                                          dma_addr_t dev_addr)
 328 {
 329         return false;
 330 }
 331
 332 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
 333 {
 334         return __get_free_pages(__GFP_NOWARN, order);
 335 }
 336
 337 #endif /* _ASM_X86_XEN_PAGE_H */