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 10 #include <asm/uaccess.h> 11 #include <asm/page.h> 12 #include <asm/pgtable.h> 13 14 #include <xen/interface/xen.h> 15 #include <xen/grant_table.h> 16 #include <xen/features.h> 17 18 /* Xen machine address */ 19 typedef struct xmaddr { 20 phys_addr_t maddr; 21 } xmaddr_t; 22 23 /* Xen pseudo-physical address */ 24 typedef struct xpaddr { 25 phys_addr_t paddr; 26 } xpaddr_t; 27 28 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) 29 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) 30 31 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ 32 #define INVALID_P2M_ENTRY (~0UL) 33 #define FOREIGN_FRAME_BIT (1UL<<(BITS_PER_LONG-1)) 34 #define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2)) 35 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) 36 #define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT) 37 38 #define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) 39 40 extern unsigned long *machine_to_phys_mapping; 41 extern unsigned long machine_to_phys_nr; 42 extern unsigned long *xen_p2m_addr; 43 extern unsigned long xen_p2m_size; 44 extern unsigned long xen_max_p2m_pfn; 45 46 extern unsigned long get_phys_to_machine(unsigned long pfn); 47 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); 48 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); 49 extern unsigned long __init set_phys_range_identity(unsigned long pfn_s, 50 unsigned long pfn_e); 51 52 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 53 struct gnttab_map_grant_ref *kmap_ops, 54 struct page **pages, unsigned int count); 55 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 56 struct gnttab_unmap_grant_ref *kunmap_ops, 57 struct page **pages, unsigned int count); 58 59 /* 60 * Helper functions to write or read unsigned long values to/from 61 * memory, when the access may fault. 62 */ 63 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val) 64 { 65 return __put_user(val, (unsigned long __user *)addr); 66 } 67 68 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val) 69 { 70 return __get_user(*val, (unsigned long __user *)addr); 71 } 72 73 /* 74 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine(): 75 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator 76 * bits (identity or foreign) are set. 77 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set 78 * identity or foreign indicator will be still set. __pfn_to_mfn() is 79 * encapsulating get_phys_to_machine() which is called in special cases only. 80 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special 81 * cases needing an extended handling. 82 */ 83 static inline unsigned long __pfn_to_mfn(unsigned long pfn) 84 { 85 unsigned long mfn; 86 87 if (pfn < xen_p2m_size) 88 mfn = xen_p2m_addr[pfn]; 89 else if (unlikely(pfn < xen_max_p2m_pfn)) 90 return get_phys_to_machine(pfn); 91 else 92 return IDENTITY_FRAME(pfn); 93 94 if (unlikely(mfn == INVALID_P2M_ENTRY)) 95 return get_phys_to_machine(pfn); 96 97 return mfn; 98 } 99 100 static inline unsigned long pfn_to_mfn(unsigned long pfn) 101 { 102 unsigned long mfn; 103 104 /* 105 * Some x86 code are still using pfn_to_mfn instead of 106 * pfn_to_mfn. This will have to be removed when we figured 107 * out which call. 108 */ 109 if (xen_feature(XENFEAT_auto_translated_physmap)) 110 return pfn; 111 112 mfn = __pfn_to_mfn(pfn); 113 114 if (mfn != INVALID_P2M_ENTRY) 115 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); 116 117 return mfn; 118 } 119 120 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 121 { 122 if (xen_feature(XENFEAT_auto_translated_physmap)) 123 return 1; 124 125 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY; 126 } 127 128 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn) 129 { 130 unsigned long pfn; 131 int ret; 132 133 if (xen_feature(XENFEAT_auto_translated_physmap)) 134 return mfn; 135 136 if (unlikely(mfn >= machine_to_phys_nr)) 137 return ~0; 138 139 /* 140 * The array access can fail (e.g., device space beyond end of RAM). 141 * In such cases it doesn't matter what we return (we return garbage), 142 * but we must handle the fault without crashing! 143 */ 144 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn); 145 if (ret < 0) 146 return ~0; 147 148 return pfn; 149 } 150 151 static inline unsigned long mfn_to_pfn(unsigned long mfn) 152 { 153 unsigned long pfn; 154 155 /* 156 * Some x86 code are still using mfn_to_pfn instead of 157 * gfn_to_pfn. This will have to be removed when we figure 158 * out which call. 159 */ 160 if (xen_feature(XENFEAT_auto_translated_physmap)) 161 return mfn; 162 163 pfn = mfn_to_pfn_no_overrides(mfn); 164 if (__pfn_to_mfn(pfn) != mfn) 165 pfn = ~0; 166 167 /* 168 * pfn is ~0 if there are no entries in the m2p for mfn or the 169 * entry doesn't map back to the mfn. 170 */ 171 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn)) 172 pfn = mfn; 173 174 return pfn; 175 } 176 177 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 178 { 179 unsigned offset = phys.paddr & ~PAGE_MASK; 180 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 181 } 182 183 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 184 { 185 unsigned offset = machine.maddr & ~PAGE_MASK; 186 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 187 } 188 189 /* Pseudo-physical <-> Guest conversion */ 190 static inline unsigned long pfn_to_gfn(unsigned long pfn) 191 { 192 if (xen_feature(XENFEAT_auto_translated_physmap)) 193 return pfn; 194 else 195 return pfn_to_mfn(pfn); 196 } 197 198 static inline unsigned long gfn_to_pfn(unsigned long gfn) 199 { 200 if (xen_feature(XENFEAT_auto_translated_physmap)) 201 return gfn; 202 else 203 return mfn_to_pfn(gfn); 204 } 205 206 /* Pseudo-physical <-> Bus conversion */ 207 #define pfn_to_bfn(pfn) pfn_to_gfn(pfn) 208 #define bfn_to_pfn(bfn) gfn_to_pfn(bfn) 209 210 /* 211 * We detect special mappings in one of two ways: 212 * 1. If the MFN is an I/O page then Xen will set the m2p entry 213 * to be outside our maximum possible pseudophys range. 214 * 2. If the MFN belongs to a different domain then we will certainly 215 * not have MFN in our p2m table. Conversely, if the page is ours, 216 * then we'll have p2m(m2p(MFN))==MFN. 217 * If we detect a special mapping then it doesn't have a 'struct page'. 218 * We force !pfn_valid() by returning an out-of-range pointer. 219 * 220 * NB. These checks require that, for any MFN that is not in our reservation, 221 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 222 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 223 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 224 * 225 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 226 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 227 * require. In all the cases we care about, the FOREIGN_FRAME bit is 228 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 229 */ 230 static inline unsigned long bfn_to_local_pfn(unsigned long mfn) 231 { 232 unsigned long pfn; 233 234 if (xen_feature(XENFEAT_auto_translated_physmap)) 235 return mfn; 236 237 pfn = mfn_to_pfn(mfn); 238 if (__pfn_to_mfn(pfn) != mfn) 239 return -1; /* force !pfn_valid() */ 240 return pfn; 241 } 242 243 /* VIRT <-> MACHINE conversion */ 244 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 245 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 246 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 247 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 248 249 /* VIRT <-> GUEST conversion */ 250 #define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) 251 #define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT)) 252 253 static inline unsigned long pte_mfn(pte_t pte) 254 { 255 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 256 } 257 258 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 259 { 260 pte_t pte; 261 262 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 263 massage_pgprot(pgprot); 264 265 return pte; 266 } 267 268 static inline pteval_t pte_val_ma(pte_t pte) 269 { 270 return pte.pte; 271 } 272 273 static inline pte_t __pte_ma(pteval_t x) 274 { 275 return (pte_t) { .pte = x }; 276 } 277 278 #define pmd_val_ma(v) ((v).pmd) 279 #ifdef __PAGETABLE_PUD_FOLDED 280 #define pud_val_ma(v) ((v).pgd.pgd) 281 #else 282 #define pud_val_ma(v) ((v).pud) 283 #endif 284 #define __pmd_ma(x) ((pmd_t) { (x) } ) 285 286 #define pgd_val_ma(x) ((x).pgd) 287 288 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid); 289 290 xmaddr_t arbitrary_virt_to_machine(void *address); 291 unsigned long arbitrary_virt_to_mfn(void *vaddr); 292 void make_lowmem_page_readonly(void *vaddr); 293 void make_lowmem_page_readwrite(void *vaddr); 294 295 #define xen_remap(cookie, size) ioremap((cookie), (size)); 296 #define xen_unmap(cookie) iounmap((cookie)) 297 298 static inline bool xen_arch_need_swiotlb(struct device *dev, 299 unsigned long pfn, 300 unsigned long bfn) 301 { 302 return false; 303 } 304 305 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order) 306 { 307 return __get_free_pages(__GFP_NOWARN, order); 308 } 309 310 #endif /* _ASM_X86_XEN_PAGE_H */ 311