1 #ifndef __XEN_PAGE_H 2 #define __XEN_PAGE_H 3 4 #include <linux/pfn.h> 5 6 #include <asm/uaccess.h> 7 #include <asm/pgtable.h> 8 9 #include <xen/features.h> 10 11 #ifdef CONFIG_X86_PAE 12 /* Xen machine address */ 13 typedef struct xmaddr { 14 unsigned long long maddr; 15 } xmaddr_t; 16 17 /* Xen pseudo-physical address */ 18 typedef struct xpaddr { 19 unsigned long long paddr; 20 } xpaddr_t; 21 #else 22 /* Xen machine address */ 23 typedef struct xmaddr { 24 unsigned long maddr; 25 } xmaddr_t; 26 27 /* Xen pseudo-physical address */ 28 typedef struct xpaddr { 29 unsigned long paddr; 30 } xpaddr_t; 31 #endif 32 33 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) 34 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) 35 36 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ 37 #define INVALID_P2M_ENTRY (~0UL) 38 #define FOREIGN_FRAME_BIT (1UL<<31) 39 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) 40 41 extern unsigned long *phys_to_machine_mapping; 42 43 static inline unsigned long pfn_to_mfn(unsigned long pfn) 44 { 45 if (xen_feature(XENFEAT_auto_translated_physmap)) 46 return pfn; 47 48 return phys_to_machine_mapping[(unsigned int)(pfn)] & 49 ~FOREIGN_FRAME_BIT; 50 } 51 52 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 53 { 54 if (xen_feature(XENFEAT_auto_translated_physmap)) 55 return 1; 56 57 return (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY); 58 } 59 60 static inline unsigned long mfn_to_pfn(unsigned long mfn) 61 { 62 unsigned long pfn; 63 64 if (xen_feature(XENFEAT_auto_translated_physmap)) 65 return mfn; 66 67 #if 0 68 if (unlikely((mfn >> machine_to_phys_order) != 0)) 69 return max_mapnr; 70 #endif 71 72 pfn = 0; 73 /* 74 * The array access can fail (e.g., device space beyond end of RAM). 75 * In such cases it doesn't matter what we return (we return garbage), 76 * but we must handle the fault without crashing! 77 */ 78 __get_user(pfn, &machine_to_phys_mapping[mfn]); 79 80 return pfn; 81 } 82 83 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 84 { 85 unsigned offset = phys.paddr & ~PAGE_MASK; 86 return XMADDR(PFN_PHYS((u64)pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 87 } 88 89 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 90 { 91 unsigned offset = machine.maddr & ~PAGE_MASK; 92 return XPADDR(PFN_PHYS((u64)mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 93 } 94 95 /* 96 * We detect special mappings in one of two ways: 97 * 1. If the MFN is an I/O page then Xen will set the m2p entry 98 * to be outside our maximum possible pseudophys range. 99 * 2. If the MFN belongs to a different domain then we will certainly 100 * not have MFN in our p2m table. Conversely, if the page is ours, 101 * then we'll have p2m(m2p(MFN))==MFN. 102 * If we detect a special mapping then it doesn't have a 'struct page'. 103 * We force !pfn_valid() by returning an out-of-range pointer. 104 * 105 * NB. These checks require that, for any MFN that is not in our reservation, 106 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 107 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 108 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 109 * 110 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 111 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 112 * require. In all the cases we care about, the FOREIGN_FRAME bit is 113 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 114 */ 115 static inline unsigned long mfn_to_local_pfn(unsigned long mfn) 116 { 117 extern unsigned long max_mapnr; 118 unsigned long pfn = mfn_to_pfn(mfn); 119 if ((pfn < max_mapnr) 120 && !xen_feature(XENFEAT_auto_translated_physmap) 121 && (phys_to_machine_mapping[pfn] != mfn)) 122 return max_mapnr; /* force !pfn_valid() */ 123 return pfn; 124 } 125 126 static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn) 127 { 128 if (xen_feature(XENFEAT_auto_translated_physmap)) { 129 BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY); 130 return; 131 } 132 phys_to_machine_mapping[pfn] = mfn; 133 } 134 135 /* VIRT <-> MACHINE conversion */ 136 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 137 #define virt_to_mfn(v) (pfn_to_mfn(PFN_DOWN(__pa(v)))) 138 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 139 140 #ifdef CONFIG_X86_PAE 141 #define pte_mfn(_pte) (((_pte).pte_low >> PAGE_SHIFT) | \ 142 (((_pte).pte_high & 0xfff) << (32-PAGE_SHIFT))) 143 144 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 145 { 146 pte_t pte; 147 148 pte.pte_high = (page_nr >> (32 - PAGE_SHIFT)) | 149 (pgprot_val(pgprot) >> 32); 150 pte.pte_high &= (__supported_pte_mask >> 32); 151 pte.pte_low = ((page_nr << PAGE_SHIFT) | pgprot_val(pgprot)); 152 pte.pte_low &= __supported_pte_mask; 153 154 return pte; 155 } 156 157 static inline unsigned long long pte_val_ma(pte_t x) 158 { 159 return x.pte; 160 } 161 #define pmd_val_ma(v) ((v).pmd) 162 #define pud_val_ma(v) ((v).pgd.pgd) 163 #define __pte_ma(x) ((pte_t) { .pte = (x) }) 164 #define __pmd_ma(x) ((pmd_t) { (x) } ) 165 #else /* !X86_PAE */ 166 #define pte_mfn(_pte) ((_pte).pte_low >> PAGE_SHIFT) 167 #define mfn_pte(pfn, prot) __pte_ma(((pfn) << PAGE_SHIFT) | pgprot_val(prot)) 168 #define pte_val_ma(x) ((x).pte) 169 #define pmd_val_ma(v) ((v).pud.pgd.pgd) 170 #define __pte_ma(x) ((pte_t) { (x) } ) 171 #endif /* CONFIG_X86_PAE */ 172 173 #define pgd_val_ma(x) ((x).pgd) 174 175 176 xmaddr_t arbitrary_virt_to_machine(unsigned long address); 177 void make_lowmem_page_readonly(void *vaddr); 178 void make_lowmem_page_readwrite(void *vaddr); 179 180 #endif /* __XEN_PAGE_H */ 181