1 #ifndef _ASM_X86_XEN_PAGE_H 2 #define _ASM_X86_XEN_PAGE_H 3 4 #include <linux/kernel.h> 5 #include <linux/types.h> 6 #include <linux/spinlock.h> 7 #include <linux/pfn.h> 8 #include <linux/mm.h> 9 #include <linux/device.h> 10 11 #include <linux/uaccess.h> 12 #include <asm/page.h> 13 #include <asm/pgtable.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 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) 30 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) 31 32 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ 33 #define INVALID_P2M_ENTRY (~0UL) 34 #define FOREIGN_FRAME_BIT (1UL<<(BITS_PER_LONG-1)) 35 #define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2)) 36 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) 37 #define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT) 38 39 #define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) 40 41 extern unsigned long *machine_to_phys_mapping; 42 extern unsigned long machine_to_phys_nr; 43 extern unsigned long *xen_p2m_addr; 44 extern unsigned long xen_p2m_size; 45 extern unsigned long xen_max_p2m_pfn; 46 47 extern int xen_alloc_p2m_entry(unsigned long pfn); 48 49 extern unsigned long get_phys_to_machine(unsigned long pfn); 50 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); 51 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); 52 extern unsigned long __init set_phys_range_identity(unsigned long pfn_s, 53 unsigned long pfn_e); 54 55 #ifdef CONFIG_XEN_PV 56 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 57 struct gnttab_map_grant_ref *kmap_ops, 58 struct page **pages, unsigned int count); 59 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 60 struct gnttab_unmap_grant_ref *kunmap_ops, 61 struct page **pages, unsigned int count); 62 #else 63 static inline int 64 set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 65 struct gnttab_map_grant_ref *kmap_ops, 66 struct page **pages, unsigned int count) 67 { 68 return 0; 69 } 70 71 static inline int 72 clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 73 struct gnttab_unmap_grant_ref *kunmap_ops, 74 struct page **pages, unsigned int count) 75 { 76 return 0; 77 } 78 #endif 79 80 /* 81 * Helper functions to write or read unsigned long values to/from 82 * memory, when the access may fault. 83 */ 84 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val) 85 { 86 return __put_user(val, (unsigned long __user *)addr); 87 } 88 89 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val) 90 { 91 return __get_user(*val, (unsigned long __user *)addr); 92 } 93 94 #ifdef CONFIG_XEN_PV 95 /* 96 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine(): 97 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator 98 * bits (identity or foreign) are set. 99 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set 100 * identity or foreign indicator will be still set. __pfn_to_mfn() is 101 * encapsulating get_phys_to_machine() which is called in special cases only. 102 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special 103 * cases needing an extended handling. 104 */ 105 static inline unsigned long __pfn_to_mfn(unsigned long pfn) 106 { 107 unsigned long mfn; 108 109 if (pfn < xen_p2m_size) 110 mfn = xen_p2m_addr[pfn]; 111 else if (unlikely(pfn < xen_max_p2m_pfn)) 112 return get_phys_to_machine(pfn); 113 else 114 return IDENTITY_FRAME(pfn); 115 116 if (unlikely(mfn == INVALID_P2M_ENTRY)) 117 return get_phys_to_machine(pfn); 118 119 return mfn; 120 } 121 #else 122 static inline unsigned long __pfn_to_mfn(unsigned long pfn) 123 { 124 return pfn; 125 } 126 #endif 127 128 static inline unsigned long pfn_to_mfn(unsigned long pfn) 129 { 130 unsigned long mfn; 131 132 /* 133 * Some x86 code are still using pfn_to_mfn instead of 134 * pfn_to_mfn. This will have to be removed when we figured 135 * out which call. 136 */ 137 if (xen_feature(XENFEAT_auto_translated_physmap)) 138 return pfn; 139 140 mfn = __pfn_to_mfn(pfn); 141 142 if (mfn != INVALID_P2M_ENTRY) 143 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); 144 145 return mfn; 146 } 147 148 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 149 { 150 if (xen_feature(XENFEAT_auto_translated_physmap)) 151 return 1; 152 153 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY; 154 } 155 156 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn) 157 { 158 unsigned long pfn; 159 int ret; 160 161 if (unlikely(mfn >= machine_to_phys_nr)) 162 return ~0; 163 164 /* 165 * The array access can fail (e.g., device space beyond end of RAM). 166 * In such cases it doesn't matter what we return (we return garbage), 167 * but we must handle the fault without crashing! 168 */ 169 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn); 170 if (ret < 0) 171 return ~0; 172 173 return pfn; 174 } 175 176 static inline unsigned long mfn_to_pfn(unsigned long mfn) 177 { 178 unsigned long pfn; 179 180 /* 181 * Some x86 code are still using mfn_to_pfn instead of 182 * gfn_to_pfn. This will have to be removed when we figure 183 * out which call. 184 */ 185 if (xen_feature(XENFEAT_auto_translated_physmap)) 186 return mfn; 187 188 pfn = mfn_to_pfn_no_overrides(mfn); 189 if (__pfn_to_mfn(pfn) != mfn) 190 pfn = ~0; 191 192 /* 193 * pfn is ~0 if there are no entries in the m2p for mfn or the 194 * entry doesn't map back to the mfn. 195 */ 196 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn)) 197 pfn = mfn; 198 199 return pfn; 200 } 201 202 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 203 { 204 unsigned offset = phys.paddr & ~PAGE_MASK; 205 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 206 } 207 208 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 209 { 210 unsigned offset = machine.maddr & ~PAGE_MASK; 211 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 212 } 213 214 /* Pseudo-physical <-> Guest conversion */ 215 static inline unsigned long pfn_to_gfn(unsigned long pfn) 216 { 217 if (xen_feature(XENFEAT_auto_translated_physmap)) 218 return pfn; 219 else 220 return pfn_to_mfn(pfn); 221 } 222 223 static inline unsigned long gfn_to_pfn(unsigned long gfn) 224 { 225 if (xen_feature(XENFEAT_auto_translated_physmap)) 226 return gfn; 227 else 228 return mfn_to_pfn(gfn); 229 } 230 231 /* Pseudo-physical <-> Bus conversion */ 232 #define pfn_to_bfn(pfn) pfn_to_gfn(pfn) 233 #define bfn_to_pfn(bfn) gfn_to_pfn(bfn) 234 235 /* 236 * We detect special mappings in one of two ways: 237 * 1. If the MFN is an I/O page then Xen will set the m2p entry 238 * to be outside our maximum possible pseudophys range. 239 * 2. If the MFN belongs to a different domain then we will certainly 240 * not have MFN in our p2m table. Conversely, if the page is ours, 241 * then we'll have p2m(m2p(MFN))==MFN. 242 * If we detect a special mapping then it doesn't have a 'struct page'. 243 * We force !pfn_valid() by returning an out-of-range pointer. 244 * 245 * NB. These checks require that, for any MFN that is not in our reservation, 246 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 247 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 248 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 249 * 250 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 251 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 252 * require. In all the cases we care about, the FOREIGN_FRAME bit is 253 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 254 */ 255 static inline unsigned long bfn_to_local_pfn(unsigned long mfn) 256 { 257 unsigned long pfn; 258 259 if (xen_feature(XENFEAT_auto_translated_physmap)) 260 return mfn; 261 262 pfn = mfn_to_pfn(mfn); 263 if (__pfn_to_mfn(pfn) != mfn) 264 return -1; /* force !pfn_valid() */ 265 return pfn; 266 } 267 268 /* VIRT <-> MACHINE conversion */ 269 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 270 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 271 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 272 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 273 274 /* VIRT <-> GUEST conversion */ 275 #define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) 276 #define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT)) 277 278 static inline unsigned long pte_mfn(pte_t pte) 279 { 280 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 281 } 282 283 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 284 { 285 pte_t pte; 286 287 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 288 massage_pgprot(pgprot); 289 290 return pte; 291 } 292 293 static inline pteval_t pte_val_ma(pte_t pte) 294 { 295 return pte.pte; 296 } 297 298 static inline pte_t __pte_ma(pteval_t x) 299 { 300 return (pte_t) { .pte = x }; 301 } 302 303 #define pmd_val_ma(v) ((v).pmd) 304 #ifdef __PAGETABLE_PUD_FOLDED 305 #define pud_val_ma(v) ((v).p4d.pgd.pgd) 306 #else 307 #define pud_val_ma(v) ((v).pud) 308 #endif 309 #define __pmd_ma(x) ((pmd_t) { (x) } ) 310 311 #ifdef __PAGETABLE_P4D_FOLDED 312 #define p4d_val_ma(x) ((x).pgd.pgd) 313 #else 314 #define p4d_val_ma(x) ((x).p4d) 315 #endif 316 317 xmaddr_t arbitrary_virt_to_machine(void *address); 318 unsigned long arbitrary_virt_to_mfn(void *vaddr); 319 void make_lowmem_page_readonly(void *vaddr); 320 void make_lowmem_page_readwrite(void *vaddr); 321 322 #define xen_remap(cookie, size) ioremap((cookie), (size)); 323 #define xen_unmap(cookie) iounmap((cookie)) 324 325 static inline bool xen_arch_need_swiotlb(struct device *dev, 326 phys_addr_t phys, 327 dma_addr_t dev_addr) 328 { 329 return false; 330 } 331 332 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order) 333 { 334 return __get_free_pages(__GFP_NOWARN, order); 335 } 336 337 #endif /* _ASM_X86_XEN_PAGE_H */ 338