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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 */
19typedef struct xmaddr {
20 phys_addr_t maddr;
21} xmaddr_t;
22
23/* Xen pseudo-physical address */
24typedef 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
42extern unsigned long *machine_to_phys_mapping;
43extern unsigned long machine_to_phys_nr;
44
45extern unsigned long get_phys_to_machine(unsigned long pfn);
46extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
47extern bool __init early_set_phys_to_machine(unsigned long pfn, unsigned long mfn);
48extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
49extern unsigned long set_phys_range_identity(unsigned long pfn_s,
50 unsigned long pfn_e);
51
52extern int m2p_add_override(unsigned long mfn, struct page *page,
53 struct gnttab_map_grant_ref *kmap_op);
54extern int m2p_remove_override(struct page *page,
55 struct gnttab_map_grant_ref *kmap_op);
56extern struct page *m2p_find_override(unsigned long mfn);
57extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
58
59static 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
74static 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
82static 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]);
101try_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
127static 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
133static 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 */
159static 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
173static inline unsigned long pte_mfn(pte_t pte)
174{
175 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
176}
177
178static 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
188static inline pteval_t pte_val_ma(pte_t pte)
189{
190 return pte.pte;
191}
192
193static 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
208void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
209
210xmaddr_t arbitrary_virt_to_machine(void *address);
211unsigned long arbitrary_virt_to_mfn(void *vaddr);
212void make_lowmem_page_readonly(void *vaddr);
213void make_lowmem_page_readwrite(void *vaddr);
214
215#endif /* _ASM_X86_XEN_PAGE_H */