1 #ifndef _ASM_X86_XEN_PAGE_H
2 #define _ASM_X86_XEN_PAGE_H
4 #include <linux/kernel.h>
5 #include <linux/types.h>
6 #include <linux/spinlock.h>
10 #include <asm/uaccess.h>
12 #include <asm/pgtable.h>
14 #include <xen/interface/xen.h>
15 #include <xen/features.h>
17 /* Xen machine address */
18 typedef struct xmaddr {
22 /* Xen pseudo-physical address */
23 typedef struct xpaddr {
27 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) })
28 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) })
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)
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))
39 extern unsigned long *machine_to_phys_mapping;
40 extern unsigned int machine_to_phys_order;
42 extern unsigned long get_phys_to_machine(unsigned long pfn);
43 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
45 static inline unsigned long pfn_to_mfn(unsigned long pfn)
49 if (xen_feature(XENFEAT_auto_translated_physmap))
52 mfn = get_phys_to_machine(pfn);
54 if (mfn != INVALID_P2M_ENTRY)
55 mfn &= ~FOREIGN_FRAME_BIT;
60 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
62 if (xen_feature(XENFEAT_auto_translated_physmap))
65 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
68 static inline unsigned long mfn_to_pfn(unsigned long mfn)
72 if (xen_feature(XENFEAT_auto_translated_physmap))
75 if (unlikely((mfn >> machine_to_phys_order) != 0))
80 * The array access can fail (e.g., device space beyond end of RAM).
81 * In such cases it doesn't matter what we return (we return garbage),
82 * but we must handle the fault without crashing!
84 __get_user(pfn, &machine_to_phys_mapping[mfn]);
89 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
91 unsigned offset = phys.paddr & ~PAGE_MASK;
92 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
95 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
97 unsigned offset = machine.maddr & ~PAGE_MASK;
98 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
102 * We detect special mappings in one of two ways:
103 * 1. If the MFN is an I/O page then Xen will set the m2p entry
104 * to be outside our maximum possible pseudophys range.
105 * 2. If the MFN belongs to a different domain then we will certainly
106 * not have MFN in our p2m table. Conversely, if the page is ours,
107 * then we'll have p2m(m2p(MFN))==MFN.
108 * If we detect a special mapping then it doesn't have a 'struct page'.
109 * We force !pfn_valid() by returning an out-of-range pointer.
111 * NB. These checks require that, for any MFN that is not in our reservation,
112 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
113 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
114 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
116 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
117 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
118 * require. In all the cases we care about, the FOREIGN_FRAME bit is
119 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
121 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
123 unsigned long pfn = mfn_to_pfn(mfn);
124 if (get_phys_to_machine(pfn) != mfn)
125 return -1; /* force !pfn_valid() */
129 /* VIRT <-> MACHINE conversion */
130 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
131 #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
132 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
133 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
135 static inline unsigned long pte_mfn(pte_t pte)
137 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
140 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
144 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
145 massage_pgprot(pgprot);
150 static inline pteval_t pte_val_ma(pte_t pte)
155 static inline pte_t __pte_ma(pteval_t x)
157 return (pte_t) { .pte = x };
160 #define pmd_val_ma(v) ((v).pmd)
161 #ifdef __PAGETABLE_PUD_FOLDED
162 #define pud_val_ma(v) ((v).pgd.pgd)
164 #define pud_val_ma(v) ((v).pud)
166 #define __pmd_ma(x) ((pmd_t) { (x) } )
168 #define pgd_val_ma(x) ((x).pgd)
170 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
172 xmaddr_t arbitrary_virt_to_machine(void *address);
173 unsigned long arbitrary_virt_to_mfn(void *vaddr);
174 void make_lowmem_page_readonly(void *vaddr);
175 void make_lowmem_page_readwrite(void *vaddr);
177 #endif /* _ASM_X86_XEN_PAGE_H */