arch/x86/include/asm/xen/page.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_XEN_PAGE_H
   3 #define _ASM_X86_XEN_PAGE_H
   4
   5 #include <linux/kernel.h>
   6 #include <linux/types.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/pfn.h>
   9 #include <linux/mm.h>
  10 #include <linux/device.h>
  11
  12 #include <linux/uaccess.h>
  13 #include <asm/page.h>
  14 #include <asm/pgtable.h>
  15
  16 #include <xen/interface/xen.h>
  17 #include <xen/interface/grant_table.h>
  18 #include <xen/features.h>
  19
  20 /* Xen machine address */
  21 typedef struct xmaddr {
  22         phys_addr_t maddr;
  23 } xmaddr_t;
  24
  25 /* Xen pseudo-physical address */
  26 typedef struct xpaddr {
  27         phys_addr_t paddr;
  28 } xpaddr_t;
  29
  30 #ifdef CONFIG_X86_64
  31 #define XEN_PHYSICAL_MASK       __sme_clr((1UL << 52) - 1)
  32 #else
  33 #define XEN_PHYSICAL_MASK       __PHYSICAL_MASK
  34 #endif
  35
  36 #define XEN_PTE_MFN_MASK        ((pteval_t)(((signed long)PAGE_MASK) & \
  37                                             XEN_PHYSICAL_MASK))
  38
  39 #define XMADDR(x)       ((xmaddr_t) { .maddr = (x) })
  40 #define XPADDR(x)       ((xpaddr_t) { .paddr = (x) })
  41
  42 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
  43 #define INVALID_P2M_ENTRY       (~0UL)
  44 #define FOREIGN_FRAME_BIT       (1UL<<(BITS_PER_LONG-1))
  45 #define IDENTITY_FRAME_BIT      (1UL<<(BITS_PER_LONG-2))
  46 #define FOREIGN_FRAME(m)        ((m) | FOREIGN_FRAME_BIT)
  47 #define IDENTITY_FRAME(m)       ((m) | IDENTITY_FRAME_BIT)
  48
  49 #define P2M_PER_PAGE            (PAGE_SIZE / sizeof(unsigned long))
  50
  51 extern unsigned long *machine_to_phys_mapping;
  52 extern unsigned long  machine_to_phys_nr;
  53 extern unsigned long *xen_p2m_addr;
  54 extern unsigned long  xen_p2m_size;
  55 extern unsigned long  xen_max_p2m_pfn;
  56
  57 extern int xen_alloc_p2m_entry(unsigned long pfn);
  58
  59 extern unsigned long get_phys_to_machine(unsigned long pfn);
  60 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  61 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
  62 extern unsigned long __init set_phys_range_identity(unsigned long pfn_s,
  63                                                     unsigned long pfn_e);
  64
  65 #ifdef CONFIG_XEN_PV
  66 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
  67                                    struct gnttab_map_grant_ref *kmap_ops,
  68                                    struct page **pages, unsigned int count);
  69 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
  70                                      struct gnttab_unmap_grant_ref *kunmap_ops,
  71                                      struct page **pages, unsigned int count);
  72 #else
  73 static inline int
  74 set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
  75                         struct gnttab_map_grant_ref *kmap_ops,
  76                         struct page **pages, unsigned int count)
  77 {
  78         return 0;
  79 }
  80
  81 static inline int
  82 clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
  83                           struct gnttab_unmap_grant_ref *kunmap_ops,
  84                           struct page **pages, unsigned int count)
  85 {
  86         return 0;
  87 }
  88 #endif
  89
  90 /*
  91  * Helper functions to write or read unsigned long values to/from
  92  * memory, when the access may fault.
  93  */
  94 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
  95 {
  96         return __put_user(val, (unsigned long __user *)addr);
  97 }
  98
  99 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val)
 100 {
 101         return __get_user(*val, (unsigned long __user *)addr);
 102 }
 103
 104 #ifdef CONFIG_XEN_PV
 105 /*
 106  * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
 107  * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
 108  *   bits (identity or foreign) are set.
 109  * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
 110  *   identity or foreign indicator will be still set. __pfn_to_mfn() is
 111  *   encapsulating get_phys_to_machine() which is called in special cases only.
 112  * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
 113  *   cases needing an extended handling.
 114  */
 115 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 116 {
 117         unsigned long mfn;
 118
 119         if (pfn < xen_p2m_size)
 120                 mfn = xen_p2m_addr[pfn];
 121         else if (unlikely(pfn < xen_max_p2m_pfn))
 122                 return get_phys_to_machine(pfn);
 123         else
 124                 return IDENTITY_FRAME(pfn);
 125
 126         if (unlikely(mfn == INVALID_P2M_ENTRY))
 127                 return get_phys_to_machine(pfn);
 128
 129         return mfn;
 130 }
 131 #else
 132 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 133 {
 134         return pfn;
 135 }
 136 #endif
 137
 138 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 139 {
 140         unsigned long mfn;
 141
 142         /*
 143          * Some x86 code are still using pfn_to_mfn instead of
 144          * pfn_to_mfn. This will have to be removed when we figured
 145          * out which call.
 146          */
 147         if (xen_feature(XENFEAT_auto_translated_physmap))
 148                 return pfn;
 149
 150         mfn = __pfn_to_mfn(pfn);
 151
 152         if (mfn != INVALID_P2M_ENTRY)
 153                 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
 154
 155         return mfn;
 156 }
 157
 158 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
 159 {
 160         if (xen_feature(XENFEAT_auto_translated_physmap))
 161                 return 1;
 162
 163         return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
 164 }
 165
 166 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
 167 {
 168         unsigned long pfn;
 169         int ret;
 170
 171         if (unlikely(mfn >= machine_to_phys_nr))
 172                 return ~0;
 173
 174         /*
 175          * The array access can fail (e.g., device space beyond end of RAM).
 176          * In such cases it doesn't matter what we return (we return garbage),
 177          * but we must handle the fault without crashing!
 178          */
 179         ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
 180         if (ret < 0)
 181                 return ~0;
 182
 183         return pfn;
 184 }
 185
 186 static inline unsigned long mfn_to_pfn(unsigned long mfn)
 187 {
 188         unsigned long pfn;
 189
 190         /*
 191          * Some x86 code are still using mfn_to_pfn instead of
 192          * gfn_to_pfn. This will have to be removed when we figure
 193          * out which call.
 194          */
 195         if (xen_feature(XENFEAT_auto_translated_physmap))
 196                 return mfn;
 197
 198         pfn = mfn_to_pfn_no_overrides(mfn);
 199         if (__pfn_to_mfn(pfn) != mfn)
 200                 pfn = ~0;
 201
 202         /*
 203          * pfn is ~0 if there are no entries in the m2p for mfn or the
 204          * entry doesn't map back to the mfn.
 205          */
 206         if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
 207                 pfn = mfn;
 208
 209         return pfn;
 210 }
 211
 212 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 213 {
 214         unsigned offset = phys.paddr & ~PAGE_MASK;
 215         return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
 216 }
 217
 218 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
 219 {
 220         unsigned offset = machine.maddr & ~PAGE_MASK;
 221         return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
 222 }
 223
 224 /* Pseudo-physical <-> Guest conversion */
 225 static inline unsigned long pfn_to_gfn(unsigned long pfn)
 226 {
 227         if (xen_feature(XENFEAT_auto_translated_physmap))
 228                 return pfn;
 229         else
 230                 return pfn_to_mfn(pfn);
 231 }
 232
 233 static inline unsigned long gfn_to_pfn(unsigned long gfn)
 234 {
 235         if (xen_feature(XENFEAT_auto_translated_physmap))
 236                 return gfn;
 237         else
 238                 return mfn_to_pfn(gfn);
 239 }
 240
 241 /* Pseudo-physical <-> Bus conversion */
 242 #define pfn_to_bfn(pfn)         pfn_to_gfn(pfn)
 243 #define bfn_to_pfn(bfn)         gfn_to_pfn(bfn)
 244
 245 /*
 246  * We detect special mappings in one of two ways:
 247  *  1. If the MFN is an I/O page then Xen will set the m2p entry
 248  *     to be outside our maximum possible pseudophys range.
 249  *  2. If the MFN belongs to a different domain then we will certainly
 250  *     not have MFN in our p2m table. Conversely, if the page is ours,
 251  *     then we'll have p2m(m2p(MFN))==MFN.
 252  * If we detect a special mapping then it doesn't have a 'struct page'.
 253  * We force !pfn_valid() by returning an out-of-range pointer.
 254  *
 255  * NB. These checks require that, for any MFN that is not in our reservation,
 256  * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 257  * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 258  * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 259  *
 260  * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 261  *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 262  *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 263  *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 264  */
 265 static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
 266 {
 267         unsigned long pfn;
 268
 269         if (xen_feature(XENFEAT_auto_translated_physmap))
 270                 return mfn;
 271
 272         pfn = mfn_to_pfn(mfn);
 273         if (__pfn_to_mfn(pfn) != mfn)
 274                 return -1; /* force !pfn_valid() */
 275         return pfn;
 276 }
 277
 278 /* VIRT <-> MACHINE conversion */
 279 #define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 280 #define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 281 #define virt_to_mfn(v)          (pfn_to_mfn(virt_to_pfn(v)))
 282 #define mfn_to_virt(m)          (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 283
 284 /* VIRT <-> GUEST conversion */
 285 #define virt_to_gfn(v)          (pfn_to_gfn(virt_to_pfn(v)))
 286 #define gfn_to_virt(g)          (__va(gfn_to_pfn(g) << PAGE_SHIFT))
 287
 288 static inline unsigned long pte_mfn(pte_t pte)
 289 {
 290         return (pte.pte & XEN_PTE_MFN_MASK) >> PAGE_SHIFT;
 291 }
 292
 293 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
 294 {
 295         pte_t pte;
 296
 297         pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
 298                         massage_pgprot(pgprot);
 299
 300         return pte;
 301 }
 302
 303 static inline pteval_t pte_val_ma(pte_t pte)
 304 {
 305         return pte.pte;
 306 }
 307
 308 static inline pte_t __pte_ma(pteval_t x)
 309 {
 310         return (pte_t) { .pte = x };
 311 }
 312
 313 #define pmd_val_ma(v) ((v).pmd)
 314 #ifdef __PAGETABLE_PUD_FOLDED
 315 #define pud_val_ma(v) ((v).p4d.pgd.pgd)
 316 #else
 317 #define pud_val_ma(v) ((v).pud)
 318 #endif
 319 #define __pmd_ma(x)     ((pmd_t) { (x) } )
 320
 321 #ifdef __PAGETABLE_P4D_FOLDED
 322 #define p4d_val_ma(x)   ((x).pgd.pgd)
 323 #else
 324 #define p4d_val_ma(x)   ((x).p4d)
 325 #endif
 326
 327 xmaddr_t arbitrary_virt_to_machine(void *address);
 328 unsigned long arbitrary_virt_to_mfn(void *vaddr);
 329 void make_lowmem_page_readonly(void *vaddr);
 330 void make_lowmem_page_readwrite(void *vaddr);
 331
 332 #define xen_remap(cookie, size) ioremap((cookie), (size));
 333 #define xen_unmap(cookie) iounmap((cookie))
 334
 335 static inline bool xen_arch_need_swiotlb(struct device *dev,
 336                                          phys_addr_t phys,
 337                                          dma_addr_t dev_addr)
 338 {
 339         return false;
 340 }
 341
 342 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
 343 {
 344         return __get_free_pages(__GFP_NOWARN, order);
 345 }
 346
 347 #endif /* _ASM_X86_XEN_PAGE_H */