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