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