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 m2p_add_override(unsigned long mfn, struct page *page, 53 struct gnttab_map_grant_ref *kmap_op); 54 extern int m2p_remove_override(struct page *page, 55 struct gnttab_map_grant_ref *kmap_op); 56 extern struct page *m2p_find_override(unsigned long mfn); 57 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn); 58 59 static inline unsigned long pfn_to_mfn(unsigned long pfn) 60 { 61 unsigned long mfn; 62 63 if (xen_feature(XENFEAT_auto_translated_physmap)) 64 return pfn; 65 66 mfn = get_phys_to_machine(pfn); 67 68 if (mfn != INVALID_P2M_ENTRY) 69 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT); 70 71 return mfn; 72 } 73 74 static inline int phys_to_machine_mapping_valid(unsigned long pfn) 75 { 76 if (xen_feature(XENFEAT_auto_translated_physmap)) 77 return 1; 78 79 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY; 80 } 81 82 static inline unsigned long mfn_to_pfn(unsigned long mfn) 83 { 84 unsigned long pfn; 85 int ret = 0; 86 87 if (xen_feature(XENFEAT_auto_translated_physmap)) 88 return mfn; 89 90 if (unlikely(mfn >= machine_to_phys_nr)) { 91 pfn = ~0; 92 goto try_override; 93 } 94 pfn = 0; 95 /* 96 * The array access can fail (e.g., device space beyond end of RAM). 97 * In such cases it doesn't matter what we return (we return garbage), 98 * but we must handle the fault without crashing! 99 */ 100 ret = __get_user(pfn, &machine_to_phys_mapping[mfn]); 101 try_override: 102 /* ret might be < 0 if there are no entries in the m2p for mfn */ 103 if (ret < 0) 104 pfn = ~0; 105 else if (get_phys_to_machine(pfn) != mfn) 106 /* 107 * If this appears to be a foreign mfn (because the pfn 108 * doesn't map back to the mfn), then check the local override 109 * table to see if there's a better pfn to use. 110 * 111 * m2p_find_override_pfn returns ~0 if it doesn't find anything. 112 */ 113 pfn = m2p_find_override_pfn(mfn, ~0); 114 115 /* 116 * pfn is ~0 if there are no entries in the m2p for mfn or if the 117 * entry doesn't map back to the mfn and m2p_override doesn't have a 118 * valid entry for it. 119 */ 120 if (pfn == ~0 && 121 get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn)) 122 pfn = mfn; 123 124 return pfn; 125 } 126 127 static inline xmaddr_t phys_to_machine(xpaddr_t phys) 128 { 129 unsigned offset = phys.paddr & ~PAGE_MASK; 130 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset); 131 } 132 133 static inline xpaddr_t machine_to_phys(xmaddr_t machine) 134 { 135 unsigned offset = machine.maddr & ~PAGE_MASK; 136 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset); 137 } 138 139 /* 140 * We detect special mappings in one of two ways: 141 * 1. If the MFN is an I/O page then Xen will set the m2p entry 142 * to be outside our maximum possible pseudophys range. 143 * 2. If the MFN belongs to a different domain then we will certainly 144 * not have MFN in our p2m table. Conversely, if the page is ours, 145 * then we'll have p2m(m2p(MFN))==MFN. 146 * If we detect a special mapping then it doesn't have a 'struct page'. 147 * We force !pfn_valid() by returning an out-of-range pointer. 148 * 149 * NB. These checks require that, for any MFN that is not in our reservation, 150 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if 151 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN. 152 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety. 153 * 154 * NB2. When deliberately mapping foreign pages into the p2m table, you *must* 155 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we 156 * require. In all the cases we care about, the FOREIGN_FRAME bit is 157 * masked (e.g., pfn_to_mfn()) so behaviour there is correct. 158 */ 159 static inline unsigned long mfn_to_local_pfn(unsigned long mfn) 160 { 161 unsigned long pfn = mfn_to_pfn(mfn); 162 if (get_phys_to_machine(pfn) != mfn) 163 return -1; /* force !pfn_valid() */ 164 return pfn; 165 } 166 167 /* VIRT <-> MACHINE conversion */ 168 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v)))) 169 #define virt_to_pfn(v) (PFN_DOWN(__pa(v))) 170 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v))) 171 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) 172 173 static inline unsigned long pte_mfn(pte_t pte) 174 { 175 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT; 176 } 177 178 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot) 179 { 180 pte_t pte; 181 182 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) | 183 massage_pgprot(pgprot); 184 185 return pte; 186 } 187 188 static inline pteval_t pte_val_ma(pte_t pte) 189 { 190 return pte.pte; 191 } 192 193 static inline pte_t __pte_ma(pteval_t x) 194 { 195 return (pte_t) { .pte = x }; 196 } 197 198 #define pmd_val_ma(v) ((v).pmd) 199 #ifdef __PAGETABLE_PUD_FOLDED 200 #define pud_val_ma(v) ((v).pgd.pgd) 201 #else 202 #define pud_val_ma(v) ((v).pud) 203 #endif 204 #define __pmd_ma(x) ((pmd_t) { (x) } ) 205 206 #define pgd_val_ma(x) ((x).pgd) 207 208 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid); 209 210 xmaddr_t arbitrary_virt_to_machine(void *address); 211 unsigned long arbitrary_virt_to_mfn(void *vaddr); 212 void make_lowmem_page_readonly(void *vaddr); 213 void make_lowmem_page_readwrite(void *vaddr); 214 215 #endif /* _ASM_X86_XEN_PAGE_H */ 216