aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/include/asm/xen/page.h
blob: 8760cc60a21c8af5bcc7be1993bdf0b67c0eeb06 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
#ifndef _ASM_X86_XEN_PAGE_H
#define _ASM_X86_XEN_PAGE_H

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/pfn.h>
#include <linux/mm.h>

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>

#include <xen/interface/xen.h>
#include <xen/features.h>

/* Xen machine address */
typedef struct xmaddr {
	phys_addr_t maddr;
} xmaddr_t;

/* Xen pseudo-physical address */
typedef struct xpaddr {
	phys_addr_t paddr;
} xpaddr_t;

#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })

/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
#define INVALID_P2M_ENTRY	(~0UL)
#define FOREIGN_FRAME_BIT	(1UL<<31)
#define FOREIGN_FRAME(m)	((m) | FOREIGN_FRAME_BIT)

/* Maximum amount of memory we can handle in a domain in pages */
#define MAX_DOMAIN_PAGES						\
    ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE))

extern unsigned long *machine_to_phys_mapping;
extern unsigned int   machine_to_phys_order;

extern unsigned long get_phys_to_machine(unsigned long pfn);
extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);

static inline unsigned long pfn_to_mfn(unsigned long pfn)
{
	unsigned long mfn;

	if (xen_feature(XENFEAT_auto_translated_physmap))
		return pfn;

	mfn = get_phys_to_machine(pfn);

	if (mfn != INVALID_P2M_ENTRY)
		mfn &= ~FOREIGN_FRAME_BIT;

	return mfn;
}

static inline int phys_to_machine_mapping_valid(unsigned long pfn)
{
	if (xen_feature(XENFEAT_auto_translated_physmap))
		return 1;

	return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
}

static inline unsigned long mfn_to_pfn(unsigned long mfn)
{
	unsigned long pfn;

	if (xen_feature(XENFEAT_auto_translated_physmap))
		return mfn;

	if (unlikely((mfn >> machine_to_phys_order) != 0))
		return ~0;

	pfn = 0;
	/*
	 * The array access can fail (e.g., device space beyond end of RAM).
	 * In such cases it doesn't matter what we return (we return garbage),
	 * but we must handle the fault without crashing!
	 */
	__get_user(pfn, &machine_to_phys_mapping[mfn]);

	return pfn;
}

static inline xmaddr_t phys_to_machine(xpaddr_t phys)
{
	unsigned offset = phys.paddr & ~PAGE_MASK;
	return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
}

static inline xpaddr_t machine_to_phys(xmaddr_t machine)
{
	unsigned offset = machine.maddr & ~PAGE_MASK;
	return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
}

/*
 * We detect special mappings in one of two ways:
 *  1. If the MFN is an I/O page then Xen will set the m2p entry
 *     to be outside our maximum possible pseudophys range.
 *  2. If the MFN belongs to a different domain then we will certainly
 *     not have MFN in our p2m table. Conversely, if the page is ours,
 *     then we'll have p2m(m2p(MFN))==MFN.
 * If we detect a special mapping then it doesn't have a 'struct page'.
 * We force !pfn_valid() by returning an out-of-range pointer.
 *
 * NB. These checks require that, for any MFN that is not in our reservation,
 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
 *
 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
 *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
 *      require. In all the cases we care about, the FOREIGN_FRAME bit is
 *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
 */
static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
{
	unsigned long pfn = mfn_to_pfn(mfn);
	if (get_phys_to_machine(pfn) != mfn)
		return -1; /* force !pfn_valid() */
	return pfn;
}

/* VIRT <-> MACHINE conversion */
#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
#define virt_to_pfn(v)          (PFN_DOWN(__pa(v)))
#define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(v)))
#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))

static inline unsigned long pte_mfn(pte_t pte)
{
	return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
}

static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
{
	pte_t pte;

	pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
			massage_pgprot(pgprot);

	return pte;
}

static inline pteval_t pte_val_ma(pte_t pte)
{
	return pte.pte;
}

static inline pte_t __pte_ma(pteval_t x)
{
	return (pte_t) { .pte = x };
}

#define pmd_val_ma(v) ((v).pmd)
#ifdef __PAGETABLE_PUD_FOLDED
#define pud_val_ma(v) ((v).pgd.pgd)
#else
#define pud_val_ma(v) ((v).pud)
#endif
#define __pmd_ma(x)	((pmd_t) { (x) } )

#define pgd_val_ma(x)	((x).pgd)

void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);

xmaddr_t arbitrary_virt_to_machine(void *address);
unsigned long arbitrary_virt_to_mfn(void *vaddr);
void make_lowmem_page_readonly(void *vaddr);
void make_lowmem_page_readwrite(void *vaddr);

#endif /* _ASM_X86_XEN_PAGE_H */