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 9 #include <asm/uaccess.h> 10 #include <asm/page.h> 11 #include <asm/pgtable.h> 12 13 #include <xen/interface/xen.h> 14 #include <xen/features.h> 15 16 /* Xen machine address */ 17 typedef struct xmaddr { 18 phys_addr_t maddr; 19 } xmaddr_t; 20 21 /* Xen pseudo-physical address */ 22 typedef struct xpaddr { 23 phys_addr_t paddr; 24 } xpaddr_t; 25 26 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) 27 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) 28 29 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ 30 #define INVALID_P2M_ENTRY (~0UL) 31 #define FOREIGN_FRAME_BIT (1UL<<31) 32 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) 33 34 /* Maximum amount of memory we can handle in a domain in pages */ 35 #define MAX_DOMAIN_PAGES \ 36 ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE)) 37 38 39 extern unsigned long get_phys_to_machine(unsigned long pfn); 40 extern void set_phys_to_machine(unsigned long pfn, unsigned long mfn); 41 42 static inline unsigned long pfn_to_mfn(unsigned long pfn) 43 { 44 if (xen_feature(XENFEAT_auto_translated_physmap)) 45 return pfn; 46 47 return get_phys_to_machine(pfn) & ~FOREIGN_FRAME_BIT; 48 } 49 50 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 51 { 52 if (xen_feature(XENFEAT_auto_translated_physmap)) 53 return 1; 54 55 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY; 56 } 57 58 static inline unsigned long mfn_to_pfn(unsigned long mfn) 59 { 60 unsigned long pfn; 61 62 if (xen_feature(XENFEAT_auto_translated_physmap)) 63 return mfn; 64 65 #if 0 66 if (unlikely((mfn >> machine_to_phys_order) != 0)) 67 return max_mapnr; 68 #endif 69 70 pfn = 0; 71 /* 72 * The array access can fail (e.g., device space beyond end of RAM). 73 * In such cases it doesn't matter what we return (we return garbage), 74 * but we must handle the fault without crashing! 75 */ 76 __get_user(pfn, &machine_to_phys_mapping[mfn]); 77 78 return pfn; 79 } 80 81 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 82 { 83 unsigned offset = phys.paddr & ~PAGE_MASK; 84 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 85 } 86 87 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 88 { 89 unsigned offset = machine.maddr & ~PAGE_MASK; 90 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 91 } 92 93 /* 94 * We detect special mappings in one of two ways: 95 * 1. If the MFN is an I/O page then Xen will set the m2p entry 96 * to be outside our maximum possible pseudophys range. 97 * 2. If the MFN belongs to a different domain then we will certainly 98 * not have MFN in our p2m table. Conversely, if the page is ours, 99 * then we'll have p2m(m2p(MFN))==MFN. 100 * If we detect a special mapping then it doesn't have a 'struct page'. 101 * We force !pfn_valid() by returning an out-of-range pointer. 102 * 103 * NB. These checks require that, for any MFN that is not in our reservation, 104 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 105 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 106 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 107 * 108 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 109 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 110 * require. In all the cases we care about, the FOREIGN_FRAME bit is 111 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 112 */ 113 static inline unsigned long mfn_to_local_pfn(unsigned long mfn) 114 { 115 extern unsigned long max_mapnr; 116 unsigned long pfn = mfn_to_pfn(mfn); 117 if ((pfn < max_mapnr) 118 && !xen_feature(XENFEAT_auto_translated_physmap) 119 && (get_phys_to_machine(pfn) != mfn)) 120 return max_mapnr; /* force !pfn_valid() */ 121 /* XXX fixme; not true with sparsemem */ 122 return pfn; 123 } 124 125 /* VIRT <-> MACHINE conversion */ 126 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 127 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 128 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 129 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 130 131 static inline unsigned long pte_mfn(pte_t pte) 132 { 133 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 134 } 135 136 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 137 { 138 pte_t pte; 139 140 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 141 massage_pgprot(pgprot); 142 143 return pte; 144 } 145 146 static inline pteval_t pte_val_ma(pte_t pte) 147 { 148 return pte.pte; 149 } 150 151 static inline pte_t __pte_ma(pteval_t x) 152 { 153 return (pte_t) { .pte = x }; 154 } 155 156 #define pmd_val_ma(v) ((v).pmd) 157 #ifdef __PAGETABLE_PUD_FOLDED 158 #define pud_val_ma(v) ((v).pgd.pgd) 159 #else 160 #define pud_val_ma(v) ((v).pud) 161 #endif 162 #define __pmd_ma(x) ((pmd_t) { (x) } ) 163 164 #define pgd_val_ma(x) ((x).pgd) 165 166 167 xmaddr_t arbitrary_virt_to_machine(void *address); 168 unsigned long arbitrary_virt_to_mfn(void *vaddr); 169 void make_lowmem_page_readonly(void *vaddr); 170 void make_lowmem_page_readwrite(void *vaddr); 171 172 #endif /* _ASM_X86_XEN_PAGE_H */ 173