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 */ 348