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