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