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>
9 #include <asm/uaccess.h>
11 #include <asm/pgtable.h>
13 #include <xen/interface/xen.h>
14 #include <xen/features.h>
16 /* Xen machine address */
17 typedef struct xmaddr
{
21 /* Xen pseudo-physical address */
22 typedef struct xpaddr
{
26 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) })
27 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) })
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)
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))
39 extern unsigned long get_phys_to_machine(unsigned long pfn
);
40 extern void set_phys_to_machine(unsigned long pfn
, unsigned long mfn
);
42 static inline unsigned long pfn_to_mfn(unsigned long pfn
)
44 if (xen_feature(XENFEAT_auto_translated_physmap
))
47 return get_phys_to_machine(pfn
) & ~FOREIGN_FRAME_BIT
;
50 static inline int phys_to_machine_mapping_valid(unsigned long pfn
)
52 if (xen_feature(XENFEAT_auto_translated_physmap
))
55 return get_phys_to_machine(pfn
) != INVALID_P2M_ENTRY
;
58 static inline unsigned long mfn_to_pfn(unsigned long mfn
)
62 if (xen_feature(XENFEAT_auto_translated_physmap
))
68 * The array access can fail (e.g., device space beyond end of RAM).
69 * In such cases it doesn't matter what we return (we return garbage),
70 * but we must handle the fault without crashing!
72 __get_user(pfn
, &machine_to_phys_mapping
[mfn
]);
77 static inline xmaddr_t
phys_to_machine(xpaddr_t phys
)
79 unsigned offset
= phys
.paddr
& ~PAGE_MASK
;
80 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys
.paddr
))) | offset
);
83 static inline xpaddr_t
machine_to_phys(xmaddr_t machine
)
85 unsigned offset
= machine
.maddr
& ~PAGE_MASK
;
86 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine
.maddr
))) | offset
);
90 * We detect special mappings in one of two ways:
91 * 1. If the MFN is an I/O page then Xen will set the m2p entry
92 * to be outside our maximum possible pseudophys range.
93 * 2. If the MFN belongs to a different domain then we will certainly
94 * not have MFN in our p2m table. Conversely, if the page is ours,
95 * then we'll have p2m(m2p(MFN))==MFN.
96 * If we detect a special mapping then it doesn't have a 'struct page'.
97 * We force !pfn_valid() by returning an out-of-range pointer.
99 * NB. These checks require that, for any MFN that is not in our reservation,
100 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
101 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
102 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
104 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
105 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
106 * require. In all the cases we care about, the FOREIGN_FRAME bit is
107 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
109 static inline unsigned long mfn_to_local_pfn(unsigned long mfn
)
111 unsigned long pfn
= mfn_to_pfn(mfn
);
112 if (get_phys_to_machine(pfn
) != mfn
)
113 return -1; /* force !pfn_valid() */
117 /* VIRT <-> MACHINE conversion */
118 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
119 #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
120 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
121 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
123 static inline unsigned long pte_mfn(pte_t pte
)
125 return (pte
.pte
& PTE_PFN_MASK
) >> PAGE_SHIFT
;
128 static inline pte_t
mfn_pte(unsigned long page_nr
, pgprot_t pgprot
)
132 pte
.pte
= ((phys_addr_t
)page_nr
<< PAGE_SHIFT
) |
133 massage_pgprot(pgprot
);
138 static inline pteval_t
pte_val_ma(pte_t pte
)
143 static inline pte_t
__pte_ma(pteval_t x
)
145 return (pte_t
) { .pte
= x
};
148 #define pmd_val_ma(v) ((v).pmd)
149 #ifdef __PAGETABLE_PUD_FOLDED
150 #define pud_val_ma(v) ((v).pgd.pgd)
152 #define pud_val_ma(v) ((v).pud)
154 #define __pmd_ma(x) ((pmd_t) { (x) } )
156 #define pgd_val_ma(x) ((x).pgd)
159 xmaddr_t
arbitrary_virt_to_machine(void *address
);
160 unsigned long arbitrary_virt_to_mfn(void *vaddr
);
161 void make_lowmem_page_readonly(void *vaddr
);
162 void make_lowmem_page_readwrite(void *vaddr
);
164 #endif /* _ASM_X86_XEN_PAGE_H */