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 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 #ifdef CONFIG_X86_64 30 #define XEN_PHYSICAL_MASK __sme_clr((1UL << 52) - 1) 31 #else 32 #define XEN_PHYSICAL_MASK __PHYSICAL_MASK 33 #endif 34 35 #define XEN_PTE_MFN_MASK ((pteval_t)(((signed long)PAGE_MASK) & \ 36 XEN_PHYSICAL_MASK)) 37 38 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) 39 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) 40 41 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ 42 #define INVALID_P2M_ENTRY (~0UL) 43 #define FOREIGN_FRAME_BIT (1UL<<(BITS_PER_LONG-1)) 44 #define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2)) 45 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) 46 #define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT) 47 48 #define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) 49 50 extern unsigned long *machine_to_phys_mapping; 51 extern unsigned long machine_to_phys_nr; 52 extern unsigned long *xen_p2m_addr; 53 extern unsigned long xen_p2m_size; 54 extern unsigned long xen_max_p2m_pfn; 55 56 extern int xen_alloc_p2m_entry(unsigned long pfn); 57 58 extern unsigned long get_phys_to_machine(unsigned long pfn); 59 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); 60 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); 61 extern unsigned long __init set_phys_range_identity(unsigned long pfn_s, 62 unsigned long pfn_e); 63 64 #ifdef CONFIG_XEN_PV 65 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 66 struct gnttab_map_grant_ref *kmap_ops, 67 struct page **pages, unsigned int count); 68 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 69 struct gnttab_unmap_grant_ref *kunmap_ops, 70 struct page **pages, unsigned int count); 71 #else 72 static inline int 73 set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 74 struct gnttab_map_grant_ref *kmap_ops, 75 struct page **pages, unsigned int count) 76 { 77 return 0; 78 } 79 80 static inline int 81 clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 82 struct gnttab_unmap_grant_ref *kunmap_ops, 83 struct page **pages, unsigned int count) 84 { 85 return 0; 86 } 87 #endif 88 89 /* 90 * Helper functions to write or read unsigned long values to/from 91 * memory, when the access may fault. 92 */ 93 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val) 94 { 95 int ret = 0; 96 97 asm volatile("1: mov %[val], %[ptr]\n" 98 "2:\n" 99 ".section .fixup, \"ax\"\n" 100 "3: sub $1, %[ret]\n" 101 " jmp 2b\n" 102 ".previous\n" 103 _ASM_EXTABLE(1b, 3b) 104 : [ret] "+r" (ret), [ptr] "=m" (*addr) 105 : [val] "r" (val)); 106 107 return ret; 108 } 109 110 static inline int xen_safe_read_ulong(const unsigned long *addr, 111 unsigned long *val) 112 { 113 int ret = 0; 114 unsigned long rval = ~0ul; 115 116 asm volatile("1: mov %[ptr], %[rval]\n" 117 "2:\n" 118 ".section .fixup, \"ax\"\n" 119 "3: sub $1, %[ret]\n" 120 " jmp 2b\n" 121 ".previous\n" 122 _ASM_EXTABLE(1b, 3b) 123 : [ret] "+r" (ret), [rval] "+r" (rval) 124 : [ptr] "m" (*addr)); 125 *val = rval; 126 127 return ret; 128 } 129 130 #ifdef CONFIG_XEN_PV 131 /* 132 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine(): 133 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator 134 * bits (identity or foreign) are set. 135 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set 136 * identity or foreign indicator will be still set. __pfn_to_mfn() is 137 * encapsulating get_phys_to_machine() which is called in special cases only. 138 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special 139 * cases needing an extended handling. 140 */ 141 static inline unsigned long __pfn_to_mfn(unsigned long pfn) 142 { 143 unsigned long mfn; 144 145 if (pfn < xen_p2m_size) 146 mfn = xen_p2m_addr[pfn]; 147 else if (unlikely(pfn < xen_max_p2m_pfn)) 148 return get_phys_to_machine(pfn); 149 else 150 return IDENTITY_FRAME(pfn); 151 152 if (unlikely(mfn == INVALID_P2M_ENTRY)) 153 return get_phys_to_machine(pfn); 154 155 return mfn; 156 } 157 #else 158 static inline unsigned long __pfn_to_mfn(unsigned long pfn) 159 { 160 return pfn; 161 } 162 #endif 163 164 static inline unsigned long pfn_to_mfn(unsigned long pfn) 165 { 166 unsigned long mfn; 167 168 /* 169 * Some x86 code are still using pfn_to_mfn instead of 170 * pfn_to_mfn. This will have to be removed when we figured 171 * out which call. 172 */ 173 if (xen_feature(XENFEAT_auto_translated_physmap)) 174 return pfn; 175 176 mfn = __pfn_to_mfn(pfn); 177 178 if (mfn != INVALID_P2M_ENTRY) 179 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); 180 181 return mfn; 182 } 183 184 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 185 { 186 if (xen_feature(XENFEAT_auto_translated_physmap)) 187 return 1; 188 189 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY; 190 } 191 192 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn) 193 { 194 unsigned long pfn; 195 int ret; 196 197 if (unlikely(mfn >= machine_to_phys_nr)) 198 return ~0; 199 200 /* 201 * The array access can fail (e.g., device space beyond end of RAM). 202 * In such cases it doesn't matter what we return (we return garbage), 203 * but we must handle the fault without crashing! 204 */ 205 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn); 206 if (ret < 0) 207 return ~0; 208 209 return pfn; 210 } 211 212 static inline unsigned long mfn_to_pfn(unsigned long mfn) 213 { 214 unsigned long pfn; 215 216 /* 217 * Some x86 code are still using mfn_to_pfn instead of 218 * gfn_to_pfn. This will have to be removed when we figure 219 * out which call. 220 */ 221 if (xen_feature(XENFEAT_auto_translated_physmap)) 222 return mfn; 223 224 pfn = mfn_to_pfn_no_overrides(mfn); 225 if (__pfn_to_mfn(pfn) != mfn) 226 pfn = ~0; 227 228 /* 229 * pfn is ~0 if there are no entries in the m2p for mfn or the 230 * entry doesn't map back to the mfn. 231 */ 232 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn)) 233 pfn = mfn; 234 235 return pfn; 236 } 237 238 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 239 { 240 unsigned offset = phys.paddr & ~PAGE_MASK; 241 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 242 } 243 244 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 245 { 246 unsigned offset = machine.maddr & ~PAGE_MASK; 247 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 248 } 249 250 /* Pseudo-physical <-> Guest conversion */ 251 static inline unsigned long pfn_to_gfn(unsigned long pfn) 252 { 253 if (xen_feature(XENFEAT_auto_translated_physmap)) 254 return pfn; 255 else 256 return pfn_to_mfn(pfn); 257 } 258 259 static inline unsigned long gfn_to_pfn(unsigned long gfn) 260 { 261 if (xen_feature(XENFEAT_auto_translated_physmap)) 262 return gfn; 263 else 264 return mfn_to_pfn(gfn); 265 } 266 267 /* Pseudo-physical <-> Bus conversion */ 268 #define pfn_to_bfn(pfn) pfn_to_gfn(pfn) 269 #define bfn_to_pfn(bfn) gfn_to_pfn(bfn) 270 271 /* 272 * We detect special mappings in one of two ways: 273 * 1. If the MFN is an I/O page then Xen will set the m2p entry 274 * to be outside our maximum possible pseudophys range. 275 * 2. If the MFN belongs to a different domain then we will certainly 276 * not have MFN in our p2m table. Conversely, if the page is ours, 277 * then we'll have p2m(m2p(MFN))==MFN. 278 * If we detect a special mapping then it doesn't have a 'struct page'. 279 * We force !pfn_valid() by returning an out-of-range pointer. 280 * 281 * NB. These checks require that, for any MFN that is not in our reservation, 282 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 283 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 284 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 285 * 286 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 287 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 288 * require. In all the cases we care about, the FOREIGN_FRAME bit is 289 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 290 */ 291 static inline unsigned long bfn_to_local_pfn(unsigned long mfn) 292 { 293 unsigned long pfn; 294 295 if (xen_feature(XENFEAT_auto_translated_physmap)) 296 return mfn; 297 298 pfn = mfn_to_pfn(mfn); 299 if (__pfn_to_mfn(pfn) != mfn) 300 return -1; /* force !pfn_valid() */ 301 return pfn; 302 } 303 304 /* VIRT <-> MACHINE conversion */ 305 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 306 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 307 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 308 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 309 310 /* VIRT <-> GUEST conversion */ 311 #define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) 312 #define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT)) 313 314 static inline unsigned long pte_mfn(pte_t pte) 315 { 316 return (pte.pte & XEN_PTE_MFN_MASK) >> PAGE_SHIFT; 317 } 318 319 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 320 { 321 pte_t pte; 322 323 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 324 massage_pgprot(pgprot); 325 326 return pte; 327 } 328 329 static inline pteval_t pte_val_ma(pte_t pte) 330 { 331 return pte.pte; 332 } 333 334 static inline pte_t __pte_ma(pteval_t x) 335 { 336 return (pte_t) { .pte = x }; 337 } 338 339 #define pmd_val_ma(v) ((v).pmd) 340 #ifdef __PAGETABLE_PUD_FOLDED 341 #define pud_val_ma(v) ((v).p4d.pgd.pgd) 342 #else 343 #define pud_val_ma(v) ((v).pud) 344 #endif 345 #define __pmd_ma(x) ((pmd_t) { (x) } ) 346 347 #ifdef __PAGETABLE_P4D_FOLDED 348 #define p4d_val_ma(x) ((x).pgd.pgd) 349 #else 350 #define p4d_val_ma(x) ((x).p4d) 351 #endif 352 353 xmaddr_t arbitrary_virt_to_machine(void *address); 354 unsigned long arbitrary_virt_to_mfn(void *vaddr); 355 void make_lowmem_page_readonly(void *vaddr); 356 void make_lowmem_page_readwrite(void *vaddr); 357 358 #define xen_remap(cookie, size) ioremap((cookie), (size)) 359 #define xen_unmap(cookie) iounmap((cookie)) 360 361 static inline bool xen_arch_need_swiotlb(struct device *dev, 362 phys_addr_t phys, 363 dma_addr_t dev_addr) 364 { 365 return false; 366 } 367 368 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order) 369 { 370 return __get_free_pages(__GFP_NOWARN, order); 371 } 372 373 #endif /* _ASM_X86_XEN_PAGE_H */ 374