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 <linux/uaccess.h> 11 #include <asm/page.h> 12 #include <asm/pgtable.h> 13 14 #include <xen/interface/xen.h> 15 #include <xen/interface/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 int xen_alloc_p2m_entry(unsigned long pfn); 47 48 extern unsigned long get_phys_to_machine(unsigned long pfn); 49 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); 50 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn); 51 extern unsigned long __init set_phys_range_identity(unsigned long pfn_s, 52 unsigned long pfn_e); 53 54 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, 55 struct gnttab_map_grant_ref *kmap_ops, 56 struct page **pages, unsigned int count); 57 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 58 struct gnttab_unmap_grant_ref *kunmap_ops, 59 struct page **pages, unsigned int count); 60 61 /* 62 * Helper functions to write or read unsigned long values to/from 63 * memory, when the access may fault. 64 */ 65 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val) 66 { 67 return __put_user(val, (unsigned long __user *)addr); 68 } 69 70 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val) 71 { 72 return __get_user(*val, (unsigned long __user *)addr); 73 } 74 75 /* 76 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine(): 77 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator 78 * bits (identity or foreign) are set. 79 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set 80 * identity or foreign indicator will be still set. __pfn_to_mfn() is 81 * encapsulating get_phys_to_machine() which is called in special cases only. 82 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special 83 * cases needing an extended handling. 84 */ 85 static inline unsigned long __pfn_to_mfn(unsigned long pfn) 86 { 87 unsigned long mfn; 88 89 if (pfn < xen_p2m_size) 90 mfn = xen_p2m_addr[pfn]; 91 else if (unlikely(pfn < xen_max_p2m_pfn)) 92 return get_phys_to_machine(pfn); 93 else 94 return IDENTITY_FRAME(pfn); 95 96 if (unlikely(mfn == INVALID_P2M_ENTRY)) 97 return get_phys_to_machine(pfn); 98 99 return mfn; 100 } 101 102 static inline unsigned long pfn_to_mfn(unsigned long pfn) 103 { 104 unsigned long mfn; 105 106 /* 107 * Some x86 code are still using pfn_to_mfn instead of 108 * pfn_to_mfn. This will have to be removed when we figured 109 * out which call. 110 */ 111 if (xen_feature(XENFEAT_auto_translated_physmap)) 112 return pfn; 113 114 mfn = __pfn_to_mfn(pfn); 115 116 if (mfn != INVALID_P2M_ENTRY) 117 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); 118 119 return mfn; 120 } 121 122 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 123 { 124 if (xen_feature(XENFEAT_auto_translated_physmap)) 125 return 1; 126 127 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY; 128 } 129 130 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn) 131 { 132 unsigned long pfn; 133 int ret; 134 135 if (xen_feature(XENFEAT_auto_translated_physmap)) 136 return mfn; 137 138 if (unlikely(mfn >= machine_to_phys_nr)) 139 return ~0; 140 141 /* 142 * The array access can fail (e.g., device space beyond end of RAM). 143 * In such cases it doesn't matter what we return (we return garbage), 144 * but we must handle the fault without crashing! 145 */ 146 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn); 147 if (ret < 0) 148 return ~0; 149 150 return pfn; 151 } 152 153 static inline unsigned long mfn_to_pfn(unsigned long mfn) 154 { 155 unsigned long pfn; 156 157 /* 158 * Some x86 code are still using mfn_to_pfn instead of 159 * gfn_to_pfn. This will have to be removed when we figure 160 * out which call. 161 */ 162 if (xen_feature(XENFEAT_auto_translated_physmap)) 163 return mfn; 164 165 pfn = mfn_to_pfn_no_overrides(mfn); 166 if (__pfn_to_mfn(pfn) != mfn) 167 pfn = ~0; 168 169 /* 170 * pfn is ~0 if there are no entries in the m2p for mfn or the 171 * entry doesn't map back to the mfn. 172 */ 173 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn)) 174 pfn = mfn; 175 176 return pfn; 177 } 178 179 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 180 { 181 unsigned offset = phys.paddr & ~PAGE_MASK; 182 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 183 } 184 185 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 186 { 187 unsigned offset = machine.maddr & ~PAGE_MASK; 188 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 189 } 190 191 /* Pseudo-physical <-> Guest conversion */ 192 static inline unsigned long pfn_to_gfn(unsigned long pfn) 193 { 194 if (xen_feature(XENFEAT_auto_translated_physmap)) 195 return pfn; 196 else 197 return pfn_to_mfn(pfn); 198 } 199 200 static inline unsigned long gfn_to_pfn(unsigned long gfn) 201 { 202 if (xen_feature(XENFEAT_auto_translated_physmap)) 203 return gfn; 204 else 205 return mfn_to_pfn(gfn); 206 } 207 208 /* Pseudo-physical <-> Bus conversion */ 209 #define pfn_to_bfn(pfn) pfn_to_gfn(pfn) 210 #define bfn_to_pfn(bfn) gfn_to_pfn(bfn) 211 212 /* 213 * We detect special mappings in one of two ways: 214 * 1. If the MFN is an I/O page then Xen will set the m2p entry 215 * to be outside our maximum possible pseudophys range. 216 * 2. If the MFN belongs to a different domain then we will certainly 217 * not have MFN in our p2m table. Conversely, if the page is ours, 218 * then we'll have p2m(m2p(MFN))==MFN. 219 * If we detect a special mapping then it doesn't have a 'struct page'. 220 * We force !pfn_valid() by returning an out-of-range pointer. 221 * 222 * NB. These checks require that, for any MFN that is not in our reservation, 223 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 224 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 225 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 226 * 227 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 228 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 229 * require. In all the cases we care about, the FOREIGN_FRAME bit is 230 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 231 */ 232 static inline unsigned long bfn_to_local_pfn(unsigned long mfn) 233 { 234 unsigned long pfn; 235 236 if (xen_feature(XENFEAT_auto_translated_physmap)) 237 return mfn; 238 239 pfn = mfn_to_pfn(mfn); 240 if (__pfn_to_mfn(pfn) != mfn) 241 return -1; /* force !pfn_valid() */ 242 return pfn; 243 } 244 245 /* VIRT <-> MACHINE conversion */ 246 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 247 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 248 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 249 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 250 251 /* VIRT <-> GUEST conversion */ 252 #define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) 253 #define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT)) 254 255 static inline unsigned long pte_mfn(pte_t pte) 256 { 257 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 258 } 259 260 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 261 { 262 pte_t pte; 263 264 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 265 massage_pgprot(pgprot); 266 267 return pte; 268 } 269 270 static inline pteval_t pte_val_ma(pte_t pte) 271 { 272 return pte.pte; 273 } 274 275 static inline pte_t __pte_ma(pteval_t x) 276 { 277 return (pte_t) { .pte = x }; 278 } 279 280 #define pmd_val_ma(v) ((v).pmd) 281 #ifdef __PAGETABLE_PUD_FOLDED 282 #define pud_val_ma(v) ((v).pgd.pgd) 283 #else 284 #define pud_val_ma(v) ((v).pud) 285 #endif 286 #define __pmd_ma(x) ((pmd_t) { (x) } ) 287 288 #define pgd_val_ma(x) ((x).pgd) 289 290 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid); 291 292 xmaddr_t arbitrary_virt_to_machine(void *address); 293 unsigned long arbitrary_virt_to_mfn(void *vaddr); 294 void make_lowmem_page_readonly(void *vaddr); 295 void make_lowmem_page_readwrite(void *vaddr); 296 297 #define xen_remap(cookie, size) ioremap((cookie), (size)); 298 #define xen_unmap(cookie) iounmap((cookie)) 299 300 static inline bool xen_arch_need_swiotlb(struct device *dev, 301 phys_addr_t phys, 302 dma_addr_t dev_addr) 303 { 304 return false; 305 } 306 307 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order) 308 { 309 return __get_free_pages(__GFP_NOWARN, order); 310 } 311 312 #endif /* _ASM_X86_XEN_PAGE_H */ 313