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 extern unsigned long *xen_p2m_addr;
  45 extern unsigned long  xen_p2m_size;
  46 extern unsigned long  xen_max_p2m_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 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         if (xen_feature(XENFEAT_auto_translated_physmap))
 107                 return pfn;
 108
 109         mfn = __pfn_to_mfn(pfn);
 110
 111         if (mfn != INVALID_P2M_ENTRY)
 112                 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
 113
 114         return mfn;
 115 }
 116
 117 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
 118 {
 119         if (xen_feature(XENFEAT_auto_translated_physmap))
 120                 return 1;
 121
 122         return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
 123 }
 124
 125 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
 126 {
 127         unsigned long pfn;
 128         int ret;
 129
 130         if (xen_feature(XENFEAT_auto_translated_physmap))
 131                 return mfn;
 132
 133         if (unlikely(mfn >= machine_to_phys_nr))
 134                 return ~0;
 135
 136         /*
 137          * The array access can fail (e.g., device space beyond end of RAM).
 138          * In such cases it doesn't matter what we return (we return garbage),
 139          * but we must handle the fault without crashing!
 140          */
 141         ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
 142         if (ret < 0)
 143                 return ~0;
 144
 145         return pfn;
 146 }
 147
 148 static inline unsigned long mfn_to_pfn(unsigned long mfn)
 149 {
 150         unsigned long pfn;
 151
 152         if (xen_feature(XENFEAT_auto_translated_physmap))
 153                 return mfn;
 154
 155         pfn = mfn_to_pfn_no_overrides(mfn);
 156         if (__pfn_to_mfn(pfn) != mfn)
 157                 pfn = ~0;
 158
 159         /*
 160          * pfn is ~0 if there are no entries in the m2p for mfn or the
 161          * entry doesn't map back to the mfn.
 162          */
 163         if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
 164                 pfn = mfn;
 165
 166         return pfn;
 167 }
 168
 169 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 170 {
 171         unsigned offset = phys.paddr & ~PAGE_MASK;
 172         return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
 173 }
 174
 175 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
 176 {
 177         unsigned offset = machine.maddr & ~PAGE_MASK;
 178         return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
 179 }
 180
 181 /*
 182  * We detect special mappings in one of two ways:
 183  *  1. If the MFN is an I/O page then Xen will set the m2p entry
 184  *     to be outside our maximum possible pseudophys range.
 185  *  2. If the MFN belongs to a different domain then we will certainly
 186  *     not have MFN in our p2m table. Conversely, if the page is ours,
 187  *     then we'll have p2m(m2p(MFN))==MFN.
 188  * If we detect a special mapping then it doesn't have a 'struct page'.
 189  * We force !pfn_valid() by returning an out-of-range pointer.
 190  *
 191  * NB. These checks require that, for any MFN that is not in our reservation,
 192  * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 193  * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 194  * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 195  *
 196  * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 197  *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 198  *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 199  *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 200  */
 201 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
 202 {
 203         unsigned long pfn;
 204
 205         if (xen_feature(XENFEAT_auto_translated_physmap))
 206                 return mfn;
 207
 208         pfn = mfn_to_pfn(mfn);
 209         if (__pfn_to_mfn(pfn) != mfn)
 210                 return -1; /* force !pfn_valid() */
 211         return pfn;
 212 }
 213
 214 /* VIRT <-> MACHINE conversion */
 215 #define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 216 #define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 217 #define virt_to_mfn(v)          (pfn_to_mfn(virt_to_pfn(v)))
 218 #define mfn_to_virt(m)          (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 219
 220 static inline unsigned long pte_mfn(pte_t pte)
 221 {
 222         return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
 223 }
 224
 225 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
 226 {
 227         pte_t pte;
 228
 229         pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
 230                         massage_pgprot(pgprot);
 231
 232         return pte;
 233 }
 234
 235 static inline pteval_t pte_val_ma(pte_t pte)
 236 {
 237         return pte.pte;
 238 }
 239
 240 static inline pte_t __pte_ma(pteval_t x)
 241 {
 242         return (pte_t) { .pte = x };
 243 }
 244
 245 #define pmd_val_ma(v) ((v).pmd)
 246 #ifdef __PAGETABLE_PUD_FOLDED
 247 #define pud_val_ma(v) ((v).pgd.pgd)
 248 #else
 249 #define pud_val_ma(v) ((v).pud)
 250 #endif
 251 #define __pmd_ma(x)     ((pmd_t) { (x) } )
 252
 253 #define pgd_val_ma(x)   ((x).pgd)
 254
 255 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
 256
 257 xmaddr_t arbitrary_virt_to_machine(void *address);
 258 unsigned long arbitrary_virt_to_mfn(void *vaddr);
 259 void make_lowmem_page_readonly(void *vaddr);
 260 void make_lowmem_page_readwrite(void *vaddr);
 261
 262 #define xen_remap(cookie, size) ioremap((cookie), (size));
 263 #define xen_unmap(cookie) iounmap((cookie))
 264
 265 static inline bool xen_arch_need_swiotlb(struct device *dev,
 266                                          unsigned long pfn,
 267                                          unsigned long mfn)
 268 {
 269         return false;
 270 }
 271
 272 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
 273 {
 274         return __get_free_pages(__GFP_NOWARN, order);
 275 }
 276
 277 #endif /* _ASM_X86_XEN_PAGE_H */