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 /* Maximum amount of memory we can handle in a domain in pages */ 39 #define MAX_DOMAIN_PAGES \ 40 ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE)) 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 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 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 if (xen_feature(XENFEAT_auto_translated_physmap)) 107 return pfn; 108 109 mfn = __pfn_to_mfn(pfn); 110 111 if (mfn != INVALID_P2M_ENTRY) 112 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); 113 114 return mfn; 115 } 116 117 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 118 { 119 if (xen_feature(XENFEAT_auto_translated_physmap)) 120 return 1; 121 122 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY; 123 } 124 125 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn) 126 { 127 unsigned long pfn; 128 int ret; 129 130 if (xen_feature(XENFEAT_auto_translated_physmap)) 131 return mfn; 132 133 if (unlikely(mfn >= machine_to_phys_nr)) 134 return ~0; 135 136 /* 137 * The array access can fail (e.g., device space beyond end of RAM). 138 * In such cases it doesn't matter what we return (we return garbage), 139 * but we must handle the fault without crashing! 140 */ 141 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn); 142 if (ret < 0) 143 return ~0; 144 145 return pfn; 146 } 147 148 static inline unsigned long mfn_to_pfn(unsigned long mfn) 149 { 150 unsigned long pfn; 151 152 if (xen_feature(XENFEAT_auto_translated_physmap)) 153 return mfn; 154 155 pfn = mfn_to_pfn_no_overrides(mfn); 156 if (__pfn_to_mfn(pfn) != mfn) 157 pfn = ~0; 158 159 /* 160 * pfn is ~0 if there are no entries in the m2p for mfn or the 161 * entry doesn't map back to the mfn. 162 */ 163 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn)) 164 pfn = mfn; 165 166 return pfn; 167 } 168 169 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 170 { 171 unsigned offset = phys.paddr & ~PAGE_MASK; 172 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 173 } 174 175 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 176 { 177 unsigned offset = machine.maddr & ~PAGE_MASK; 178 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 179 } 180 181 /* 182 * We detect special mappings in one of two ways: 183 * 1. If the MFN is an I/O page then Xen will set the m2p entry 184 * to be outside our maximum possible pseudophys range. 185 * 2. If the MFN belongs to a different domain then we will certainly 186 * not have MFN in our p2m table. Conversely, if the page is ours, 187 * then we'll have p2m(m2p(MFN))==MFN. 188 * If we detect a special mapping then it doesn't have a 'struct page'. 189 * We force !pfn_valid() by returning an out-of-range pointer. 190 * 191 * NB. These checks require that, for any MFN that is not in our reservation, 192 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 193 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 194 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 195 * 196 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 197 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 198 * require. In all the cases we care about, the FOREIGN_FRAME bit is 199 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 200 */ 201 static inline unsigned long mfn_to_local_pfn(unsigned long mfn) 202 { 203 unsigned long pfn; 204 205 if (xen_feature(XENFEAT_auto_translated_physmap)) 206 return mfn; 207 208 pfn = mfn_to_pfn(mfn); 209 if (__pfn_to_mfn(pfn) != mfn) 210 return -1; /* force !pfn_valid() */ 211 return pfn; 212 } 213 214 /* VIRT <-> MACHINE conversion */ 215 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 216 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 217 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 218 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 219 220 static inline unsigned long pte_mfn(pte_t pte) 221 { 222 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 223 } 224 225 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 226 { 227 pte_t pte; 228 229 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 230 massage_pgprot(pgprot); 231 232 return pte; 233 } 234 235 static inline pteval_t pte_val_ma(pte_t pte) 236 { 237 return pte.pte; 238 } 239 240 static inline pte_t __pte_ma(pteval_t x) 241 { 242 return (pte_t) { .pte = x }; 243 } 244 245 #define pmd_val_ma(v) ((v).pmd) 246 #ifdef __PAGETABLE_PUD_FOLDED 247 #define pud_val_ma(v) ((v).pgd.pgd) 248 #else 249 #define pud_val_ma(v) ((v).pud) 250 #endif 251 #define __pmd_ma(x) ((pmd_t) { (x) } ) 252 253 #define pgd_val_ma(x) ((x).pgd) 254 255 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid); 256 257 xmaddr_t arbitrary_virt_to_machine(void *address); 258 unsigned long arbitrary_virt_to_mfn(void *vaddr); 259 void make_lowmem_page_readonly(void *vaddr); 260 void make_lowmem_page_readwrite(void *vaddr); 261 262 #define xen_remap(cookie, size) ioremap((cookie), (size)); 263 #define xen_unmap(cookie) iounmap((cookie)) 264 265 static inline bool xen_arch_need_swiotlb(struct device *dev, 266 unsigned long pfn, 267 unsigned long mfn) 268 { 269 return false; 270 } 271 272 #endif /* _ASM_X86_XEN_PAGE_H */ 273