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 45 extern unsigned long get_phys_to_machine(unsigned long pfn); 46 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); 47 extern bool __init early_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 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 m2p_add_override(unsigned long mfn, struct page *page, 56 struct gnttab_map_grant_ref *kmap_op); 57 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, 58 struct gnttab_map_grant_ref *kmap_ops, 59 struct page **pages, unsigned int count); 60 extern int m2p_remove_override(struct page *page, 61 struct gnttab_map_grant_ref *kmap_op, 62 unsigned long mfn); 63 extern struct page *m2p_find_override(unsigned long mfn); 64 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); 65 66 static inline unsigned long pfn_to_mfn(unsigned long pfn) 67 { 68 unsigned long mfn; 69 70 if (xen_feature(XENFEAT_auto_translated_physmap)) 71 return pfn; 72 73 mfn = get_phys_to_machine(pfn); 74 75 if (mfn != INVALID_P2M_ENTRY) 76 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); 77 78 return mfn; 79 } 80 81 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 82 { 83 if (xen_feature(XENFEAT_auto_translated_physmap)) 84 return 1; 85 86 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY; 87 } 88 89 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn) 90 { 91 unsigned long pfn; 92 int ret; 93 94 if (xen_feature(XENFEAT_auto_translated_physmap)) 95 return mfn; 96 97 if (unlikely(mfn >= machine_to_phys_nr)) 98 return ~0; 99 100 /* 101 * The array access can fail (e.g., device space beyond end of RAM). 102 * In such cases it doesn't matter what we return (we return garbage), 103 * but we must handle the fault without crashing! 104 */ 105 ret = __get_user(pfn, &machine_to_phys_mapping[mfn]); 106 if (ret < 0) 107 return ~0; 108 109 return pfn; 110 } 111 112 static inline unsigned long mfn_to_pfn(unsigned long mfn) 113 { 114 unsigned long pfn; 115 116 if (xen_feature(XENFEAT_auto_translated_physmap)) 117 return mfn; 118 119 pfn = mfn_to_pfn_no_overrides(mfn); 120 if (get_phys_to_machine(pfn) != mfn) { 121 /* 122 * If this appears to be a foreign mfn (because the pfn 123 * doesn't map back to the mfn), then check the local override 124 * table to see if there's a better pfn to use. 125 * 126 * m2p_find_override_pfn returns ~0 if it doesn't find anything. 127 */ 128 pfn = m2p_find_override_pfn(mfn, ~0); 129 } 130 131 /* 132 * pfn is ~0 if there are no entries in the m2p for mfn or if the 133 * entry doesn't map back to the mfn and m2p_override doesn't have a 134 * valid entry for it. 135 */ 136 if (pfn == ~0 && 137 get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn)) 138 pfn = mfn; 139 140 return pfn; 141 } 142 143 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 144 { 145 unsigned offset = phys.paddr & ~PAGE_MASK; 146 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 147 } 148 149 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 150 { 151 unsigned offset = machine.maddr & ~PAGE_MASK; 152 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 153 } 154 155 /* 156 * We detect special mappings in one of two ways: 157 * 1. If the MFN is an I/O page then Xen will set the m2p entry 158 * to be outside our maximum possible pseudophys range. 159 * 2. If the MFN belongs to a different domain then we will certainly 160 * not have MFN in our p2m table. Conversely, if the page is ours, 161 * then we'll have p2m(m2p(MFN))==MFN. 162 * If we detect a special mapping then it doesn't have a 'struct page'. 163 * We force !pfn_valid() by returning an out-of-range pointer. 164 * 165 * NB. These checks require that, for any MFN that is not in our reservation, 166 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 167 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 168 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 169 * 170 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 171 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 172 * require. In all the cases we care about, the FOREIGN_FRAME bit is 173 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 174 */ 175 static inline unsigned long mfn_to_local_pfn(unsigned long mfn) 176 { 177 unsigned long pfn; 178 179 if (xen_feature(XENFEAT_auto_translated_physmap)) 180 return mfn; 181 182 pfn = mfn_to_pfn(mfn); 183 if (get_phys_to_machine(pfn) != mfn) 184 return -1; /* force !pfn_valid() */ 185 return pfn; 186 } 187 188 /* VIRT <-> MACHINE conversion */ 189 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 190 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 191 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 192 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 193 194 static inline unsigned long pte_mfn(pte_t pte) 195 { 196 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 197 } 198 199 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 200 { 201 pte_t pte; 202 203 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 204 massage_pgprot(pgprot); 205 206 return pte; 207 } 208 209 static inline pteval_t pte_val_ma(pte_t pte) 210 { 211 return pte.pte; 212 } 213 214 static inline pte_t __pte_ma(pteval_t x) 215 { 216 return (pte_t) { .pte = x }; 217 } 218 219 #define pmd_val_ma(v) ((v).pmd) 220 #ifdef __PAGETABLE_PUD_FOLDED 221 #define pud_val_ma(v) ((v).pgd.pgd) 222 #else 223 #define pud_val_ma(v) ((v).pud) 224 #endif 225 #define __pmd_ma(x) ((pmd_t) { (x) } ) 226 227 #define pgd_val_ma(x) ((x).pgd) 228 229 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid); 230 231 xmaddr_t arbitrary_virt_to_machine(void *address); 232 unsigned long arbitrary_virt_to_mfn(void *vaddr); 233 void make_lowmem_page_readonly(void *vaddr); 234 void make_lowmem_page_readwrite(void *vaddr); 235 236 #define xen_remap(cookie, size) ioremap((cookie), (size)); 237 #define xen_unmap(cookie) iounmap((cookie)) 238 239 #endif /* _ASM_X86_XEN_PAGE_H */ 240