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

INCLUDED FROM

DEFINITIONS

1. set_foreign_p2m_mapping
2. clear_foreign_p2m_mapping
3. xen_safe_write_ulong
4. xen_safe_read_ulong
5. __pfn_to_mfn
6. __pfn_to_mfn
7. pfn_to_mfn
8. phys_to_machine_mapping_valid
9. mfn_to_pfn_no_overrides
10. mfn_to_pfn
11. phys_to_machine
12. machine_to_phys
13. pfn_to_gfn
14. gfn_to_pfn
15. bfn_to_local_pfn
16. pte_mfn
17. mfn_pte
18. pte_val_ma
19. __pte_ma
20. xen_arch_need_swiotlb
21. xen_get_swiotlb_free_pages

   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 <asm/extable.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         int ret = 0;
  97 
  98         asm volatile("1: mov %[val], %[ptr]\n"
  99                      "2:\n"
 100                      ".section .fixup, \"ax\"\n"
 101                      "3: sub $1, %[ret]\n"
 102                      "   jmp 2b\n"
 103                      ".previous\n"
 104                      _ASM_EXTABLE(1b, 3b)
 105                      : [ret] "+r" (ret), [ptr] "=m" (*addr)
 106                      : [val] "r" (val));
 107 
 108         return ret;
 109 }
 110 
 111 static inline int xen_safe_read_ulong(const unsigned long *addr,
 112                                       unsigned long *val)
 113 {
 114         int ret = 0;
 115         unsigned long rval = ~0ul;
 116 
 117         asm volatile("1: mov %[ptr], %[rval]\n"
 118                      "2:\n"
 119                      ".section .fixup, \"ax\"\n"
 120                      "3: sub $1, %[ret]\n"
 121                      "   jmp 2b\n"
 122                      ".previous\n"
 123                      _ASM_EXTABLE(1b, 3b)
 124                      : [ret] "+r" (ret), [rval] "+r" (rval)
 125                      : [ptr] "m" (*addr));
 126         *val = rval;
 127 
 128         return ret;
 129 }
 130 
 131 #ifdef CONFIG_XEN_PV
 132 /*
 133  * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
 134  * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
 135  *   bits (identity or foreign) are set.
 136  * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
 137  *   identity or foreign indicator will be still set. __pfn_to_mfn() is
 138  *   encapsulating get_phys_to_machine() which is called in special cases only.
 139  * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
 140  *   cases needing an extended handling.
 141  */
 142 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 143 {
 144         unsigned long mfn;
 145 
 146         if (pfn < xen_p2m_size)
 147                 mfn = xen_p2m_addr[pfn];
 148         else if (unlikely(pfn < xen_max_p2m_pfn))
 149                 return get_phys_to_machine(pfn);
 150         else
 151                 return IDENTITY_FRAME(pfn);
 152 
 153         if (unlikely(mfn == INVALID_P2M_ENTRY))
 154                 return get_phys_to_machine(pfn);
 155 
 156         return mfn;
 157 }
 158 #else
 159 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 160 {
 161         return pfn;
 162 }
 163 #endif
 164 
 165 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 166 {
 167         unsigned long mfn;
 168 
 169         /*
 170          * Some x86 code are still using pfn_to_mfn instead of
 171          * pfn_to_mfn. This will have to be removed when we figured
 172          * out which call.
 173          */
 174         if (xen_feature(XENFEAT_auto_translated_physmap))
 175                 return pfn;
 176 
 177         mfn = __pfn_to_mfn(pfn);
 178 
 179         if (mfn != INVALID_P2M_ENTRY)
 180                 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
 181 
 182         return mfn;
 183 }
 184 
 185 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
 186 {
 187         if (xen_feature(XENFEAT_auto_translated_physmap))
 188                 return 1;
 189 
 190         return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
 191 }
 192 
 193 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
 194 {
 195         unsigned long pfn;
 196         int ret;
 197 
 198         if (unlikely(mfn >= machine_to_phys_nr))
 199                 return ~0;
 200 
 201         /*
 202          * The array access can fail (e.g., device space beyond end of RAM).
 203          * In such cases it doesn't matter what we return (we return garbage),
 204          * but we must handle the fault without crashing!
 205          */
 206         ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
 207         if (ret < 0)
 208                 return ~0;
 209 
 210         return pfn;
 211 }
 212 
 213 static inline unsigned long mfn_to_pfn(unsigned long mfn)
 214 {
 215         unsigned long pfn;
 216 
 217         /*
 218          * Some x86 code are still using mfn_to_pfn instead of
 219          * gfn_to_pfn. This will have to be removed when we figure
 220          * out which call.
 221          */
 222         if (xen_feature(XENFEAT_auto_translated_physmap))
 223                 return mfn;
 224 
 225         pfn = mfn_to_pfn_no_overrides(mfn);
 226         if (__pfn_to_mfn(pfn) != mfn)
 227                 pfn = ~0;
 228 
 229         /*
 230          * pfn is ~0 if there are no entries in the m2p for mfn or the
 231          * entry doesn't map back to the mfn.
 232          */
 233         if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
 234                 pfn = mfn;
 235 
 236         return pfn;
 237 }
 238 
 239 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
 240 {
 241         unsigned offset = phys.paddr & ~PAGE_MASK;
 242         return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
 243 }
 244 
 245 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
 246 {
 247         unsigned offset = machine.maddr & ~PAGE_MASK;
 248         return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
 249 }
 250 
 251 /* Pseudo-physical <-> Guest conversion */
 252 static inline unsigned long pfn_to_gfn(unsigned long pfn)
 253 {
 254         if (xen_feature(XENFEAT_auto_translated_physmap))
 255                 return pfn;
 256         else
 257                 return pfn_to_mfn(pfn);
 258 }
 259 
 260 static inline unsigned long gfn_to_pfn(unsigned long gfn)
 261 {
 262         if (xen_feature(XENFEAT_auto_translated_physmap))
 263                 return gfn;
 264         else
 265                 return mfn_to_pfn(gfn);
 266 }
 267 
 268 /* Pseudo-physical <-> Bus conversion */
 269 #define pfn_to_bfn(pfn)         pfn_to_gfn(pfn)
 270 #define bfn_to_pfn(bfn)         gfn_to_pfn(bfn)
 271 
 272 /*
 273  * We detect special mappings in one of two ways:
 274  *  1. If the MFN is an I/O page then Xen will set the m2p entry
 275  *     to be outside our maximum possible pseudophys range.
 276  *  2. If the MFN belongs to a different domain then we will certainly
 277  *     not have MFN in our p2m table. Conversely, if the page is ours,
 278  *     then we'll have p2m(m2p(MFN))==MFN.
 279  * If we detect a special mapping then it doesn't have a 'struct page'.
 280  * We force !pfn_valid() by returning an out-of-range pointer.
 281  *
 282  * NB. These checks require that, for any MFN that is not in our reservation,
 283  * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 284  * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 285  * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 286  *
 287  * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 288  *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 289  *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 290  *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 291  */
 292 static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
 293 {
 294         unsigned long pfn;
 295 
 296         if (xen_feature(XENFEAT_auto_translated_physmap))
 297                 return mfn;
 298 
 299         pfn = mfn_to_pfn(mfn);
 300         if (__pfn_to_mfn(pfn) != mfn)
 301                 return -1; /* force !pfn_valid() */
 302         return pfn;
 303 }
 304 
 305 /* VIRT <-> MACHINE conversion */
 306 #define virt_to_machine(v)      (phys_to_machine(XPADDR(__pa(v))))
 307 #define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
 308 #define virt_to_mfn(v)          (pfn_to_mfn(virt_to_pfn(v)))
 309 #define mfn_to_virt(m)          (__va(mfn_to_pfn(m) << PAGE_SHIFT))
 310 
 311 /* VIRT <-> GUEST conversion */
 312 #define virt_to_gfn(v)          (pfn_to_gfn(virt_to_pfn(v)))
 313 #define gfn_to_virt(g)          (__va(gfn_to_pfn(g) << PAGE_SHIFT))
 314 
 315 static inline unsigned long pte_mfn(pte_t pte)
 316 {
 317         return (pte.pte & XEN_PTE_MFN_MASK) >> PAGE_SHIFT;
 318 }
 319 
 320 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
 321 {
 322         pte_t pte;
 323 
 324         pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
 325                         massage_pgprot(pgprot);
 326 
 327         return pte;
 328 }
 329 
 330 static inline pteval_t pte_val_ma(pte_t pte)
 331 {
 332         return pte.pte;
 333 }
 334 
 335 static inline pte_t __pte_ma(pteval_t x)
 336 {
 337         return (pte_t) { .pte = x };
 338 }
 339 
 340 #define pmd_val_ma(v) ((v).pmd)
 341 #ifdef __PAGETABLE_PUD_FOLDED
 342 #define pud_val_ma(v) ((v).p4d.pgd.pgd)
 343 #else
 344 #define pud_val_ma(v) ((v).pud)
 345 #endif
 346 #define __pmd_ma(x)     ((pmd_t) { (x) } )
 347 
 348 #ifdef __PAGETABLE_P4D_FOLDED
 349 #define p4d_val_ma(x)   ((x).pgd.pgd)
 350 #else
 351 #define p4d_val_ma(x)   ((x).p4d)
 352 #endif
 353 
 354 xmaddr_t arbitrary_virt_to_machine(void *address);
 355 unsigned long arbitrary_virt_to_mfn(void *vaddr);
 356 void make_lowmem_page_readonly(void *vaddr);
 357 void make_lowmem_page_readwrite(void *vaddr);
 358 
 359 #define xen_remap(cookie, size) ioremap((cookie), (size));
 360 #define xen_unmap(cookie) iounmap((cookie))
 361 
 362 static inline bool xen_arch_need_swiotlb(struct device *dev,
 363                                          phys_addr_t phys,
 364                                          dma_addr_t dev_addr)
 365 {
 366         return false;
 367 }
 368 
 369 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
 370 {
 371         return __get_free_pages(__GFP_NOWARN, order);
 372 }
 373 
 374 #endif /* _ASM_X86_XEN_PAGE_H */