1 #ifndef _ASM_X86_XEN_PAGE_H 2 #define _ASM_X86_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 /* Xen machine address */ 12 typedef struct xmaddr { 13 phys_addr_t maddr; 14 } xmaddr_t; 15 16 /* Xen pseudo-physical address */ 17 typedef struct xpaddr { 18 phys_addr_t paddr; 19 } xpaddr_t; 20 21 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) 22 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) 23 24 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ 25 #define INVALID_P2M_ENTRY (~0UL) 26 #define FOREIGN_FRAME_BIT (1UL<<31) 27 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) 28 29 /* Maximum amount of memory we can handle in a domain in pages */ 30 #define MAX_DOMAIN_PAGES \ 31 ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE)) 32 33 34 extern unsigned long get_phys_to_machine(unsigned long pfn); 35 extern void set_phys_to_machine(unsigned long pfn, unsigned long mfn); 36 37 static inline unsigned long pfn_to_mfn(unsigned long pfn) 38 { 39 if (xen_feature(XENFEAT_auto_translated_physmap)) 40 return pfn; 41 42 return get_phys_to_machine(pfn) & ~FOREIGN_FRAME_BIT; 43 } 44 45 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 46 { 47 if (xen_feature(XENFEAT_auto_translated_physmap)) 48 return 1; 49 50 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY; 51 } 52 53 static inline unsigned long mfn_to_pfn(unsigned long mfn) 54 { 55 unsigned long pfn; 56 57 if (xen_feature(XENFEAT_auto_translated_physmap)) 58 return mfn; 59 60 #if 0 61 if (unlikely((mfn >> machine_to_phys_order) != 0)) 62 return max_mapnr; 63 #endif 64 65 pfn = 0; 66 /* 67 * The array access can fail (e.g., device space beyond end of RAM). 68 * In such cases it doesn't matter what we return (we return garbage), 69 * but we must handle the fault without crashing! 70 */ 71 __get_user(pfn, &machine_to_phys_mapping[mfn]); 72 73 return pfn; 74 } 75 76 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 77 { 78 unsigned offset = phys.paddr & ~PAGE_MASK; 79 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 80 } 81 82 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 83 { 84 unsigned offset = machine.maddr & ~PAGE_MASK; 85 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 86 } 87 88 /* 89 * We detect special mappings in one of two ways: 90 * 1. If the MFN is an I/O page then Xen will set the m2p entry 91 * to be outside our maximum possible pseudophys range. 92 * 2. If the MFN belongs to a different domain then we will certainly 93 * not have MFN in our p2m table. Conversely, if the page is ours, 94 * then we'll have p2m(m2p(MFN))==MFN. 95 * If we detect a special mapping then it doesn't have a 'struct page'. 96 * We force !pfn_valid() by returning an out-of-range pointer. 97 * 98 * NB. These checks require that, for any MFN that is not in our reservation, 99 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 100 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 101 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 102 * 103 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 104 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 105 * require. In all the cases we care about, the FOREIGN_FRAME bit is 106 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 107 */ 108 static inline unsigned long mfn_to_local_pfn(unsigned long mfn) 109 { 110 extern unsigned long max_mapnr; 111 unsigned long pfn = mfn_to_pfn(mfn); 112 if ((pfn < max_mapnr) 113 && !xen_feature(XENFEAT_auto_translated_physmap) 114 && (get_phys_to_machine(pfn) != mfn)) 115 return max_mapnr; /* force !pfn_valid() */ 116 /* XXX fixme; not true with sparsemem */ 117 return pfn; 118 } 119 120 /* VIRT <-> MACHINE conversion */ 121 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 122 #define virt_to_mfn(v) (pfn_to_mfn(PFN_DOWN(__pa(v)))) 123 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 124 125 static inline unsigned long pte_mfn(pte_t pte) 126 { 127 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 128 } 129 130 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 131 { 132 pte_t pte; 133 134 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 135 (pgprot_val(pgprot) & __supported_pte_mask); 136 137 return pte; 138 } 139 140 static inline pteval_t pte_val_ma(pte_t pte) 141 { 142 return pte.pte; 143 } 144 145 static inline pte_t __pte_ma(pteval_t x) 146 { 147 return (pte_t) { .pte = x }; 148 } 149 150 #define pmd_val_ma(v) ((v).pmd) 151 #ifdef __PAGETABLE_PUD_FOLDED 152 #define pud_val_ma(v) ((v).pgd.pgd) 153 #else 154 #define pud_val_ma(v) ((v).pud) 155 #endif 156 #define __pmd_ma(x) ((pmd_t) { (x) } ) 157 158 #define pgd_val_ma(x) ((x).pgd) 159 160 161 xmaddr_t arbitrary_virt_to_machine(void *address); 162 void make_lowmem_page_readonly(void *vaddr); 163 void make_lowmem_page_readwrite(void *vaddr); 164 165 #endif /* _ASM_X86_XEN_PAGE_H */ 166