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