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/features.h> 16 17 /* Xen machine address */ 18 typedef struct xmaddr { 19 phys_addr_t maddr; 20 } xmaddr_t; 21 22 /* Xen pseudo-physical address */ 23 typedef struct xpaddr { 24 phys_addr_t paddr; 25 } xpaddr_t; 26 27 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) }) 28 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) }) 29 30 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/ 31 #define INVALID_P2M_ENTRY (~0UL) 32 #define FOREIGN_FRAME_BIT (1UL<<31) 33 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT) 34 35 /* Maximum amount of memory we can handle in a domain in pages */ 36 #define MAX_DOMAIN_PAGES \ 37 ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE)) 38 39 extern unsigned long *machine_to_phys_mapping; 40 extern unsigned int machine_to_phys_order; 41 42 extern unsigned long get_phys_to_machine(unsigned long pfn); 43 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); 44 45 extern int m2p_add_override(unsigned long mfn, struct page *page); 46 extern int m2p_remove_override(struct page *page); 47 extern struct page *m2p_find_override(unsigned long mfn); 48 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); 49 50 static inline unsigned long pfn_to_mfn(unsigned long pfn) 51 { 52 unsigned long mfn; 53 54 if (xen_feature(XENFEAT_auto_translated_physmap)) 55 return pfn; 56 57 mfn = get_phys_to_machine(pfn); 58 59 if (mfn != INVALID_P2M_ENTRY) 60 mfn &= ~FOREIGN_FRAME_BIT; 61 62 return mfn; 63 } 64 65 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 66 { 67 if (xen_feature(XENFEAT_auto_translated_physmap)) 68 return 1; 69 70 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY; 71 } 72 73 static inline unsigned long mfn_to_pfn(unsigned long mfn) 74 { 75 unsigned long pfn; 76 77 if (xen_feature(XENFEAT_auto_translated_physmap)) 78 return mfn; 79 80 pfn = 0; 81 /* 82 * The array access can fail (e.g., device space beyond end of RAM). 83 * In such cases it doesn't matter what we return (we return garbage), 84 * but we must handle the fault without crashing! 85 */ 86 __get_user(pfn, &machine_to_phys_mapping[mfn]); 87 88 /* 89 * If this appears to be a foreign mfn (because the pfn 90 * doesn't map back to the mfn), then check the local override 91 * table to see if there's a better pfn to use. 92 */ 93 if (get_phys_to_machine(pfn) != mfn) 94 pfn = m2p_find_override_pfn(mfn, pfn); 95 96 return pfn; 97 } 98 99 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 100 { 101 unsigned offset = phys.paddr & ~PAGE_MASK; 102 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 103 } 104 105 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 106 { 107 unsigned offset = machine.maddr & ~PAGE_MASK; 108 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 109 } 110 111 /* 112 * We detect special mappings in one of two ways: 113 * 1. If the MFN is an I/O page then Xen will set the m2p entry 114 * to be outside our maximum possible pseudophys range. 115 * 2. If the MFN belongs to a different domain then we will certainly 116 * not have MFN in our p2m table. Conversely, if the page is ours, 117 * then we'll have p2m(m2p(MFN))==MFN. 118 * If we detect a special mapping then it doesn't have a 'struct page'. 119 * We force !pfn_valid() by returning an out-of-range pointer. 120 * 121 * NB. These checks require that, for any MFN that is not in our reservation, 122 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 123 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 124 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 125 * 126 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 127 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 128 * require. In all the cases we care about, the FOREIGN_FRAME bit is 129 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 130 */ 131 static inline unsigned long mfn_to_local_pfn(unsigned long mfn) 132 { 133 unsigned long pfn = mfn_to_pfn(mfn); 134 if (get_phys_to_machine(pfn) != mfn) 135 return -1; /* force !pfn_valid() */ 136 return pfn; 137 } 138 139 /* VIRT <-> MACHINE conversion */ 140 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 141 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 142 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 143 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 144 145 static inline unsigned long pte_mfn(pte_t pte) 146 { 147 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 148 } 149 150 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 151 { 152 pte_t pte; 153 154 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 155 massage_pgprot(pgprot); 156 157 return pte; 158 } 159 160 static inline pteval_t pte_val_ma(pte_t pte) 161 { 162 return pte.pte; 163 } 164 165 static inline pte_t __pte_ma(pteval_t x) 166 { 167 return (pte_t) { .pte = x }; 168 } 169 170 #define pmd_val_ma(v) ((v).pmd) 171 #ifdef __PAGETABLE_PUD_FOLDED 172 #define pud_val_ma(v) ((v).pgd.pgd) 173 #else 174 #define pud_val_ma(v) ((v).pud) 175 #endif 176 #define __pmd_ma(x) ((pmd_t) { (x) } ) 177 178 #define pgd_val_ma(x) ((x).pgd) 179 180 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid); 181 182 xmaddr_t arbitrary_virt_to_machine(void *address); 183 unsigned long arbitrary_virt_to_mfn(void *vaddr); 184 void make_lowmem_page_readonly(void *vaddr); 185 void make_lowmem_page_readwrite(void *vaddr); 186 187 #endif /* _ASM_X86_XEN_PAGE_H */ 188