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 */ 375