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/grant_table.h>
16 #include <xen/features.h>
18 /* Xen machine address */
19 typedef struct xmaddr {
23 /* Xen pseudo-physical address */
24 typedef struct xpaddr {
28 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) })
29 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) })
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)
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))
42 extern unsigned long *machine_to_phys_mapping;
43 extern unsigned long machine_to_phys_nr;
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,
52 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
53 struct gnttab_map_grant_ref *kmap_ops,
54 struct page **pages, unsigned int count);
55 extern int m2p_add_override(unsigned long mfn, struct page *page,
56 struct gnttab_map_grant_ref *kmap_op);
57 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
58 struct gnttab_map_grant_ref *kmap_ops,
59 struct page **pages, unsigned int count);
60 extern int m2p_remove_override(struct page *page,
61 struct gnttab_map_grant_ref *kmap_op,
63 extern struct page *m2p_find_override(unsigned long mfn);
64 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
66 static inline unsigned long pfn_to_mfn(unsigned long pfn)
70 if (xen_feature(XENFEAT_auto_translated_physmap))
73 mfn = get_phys_to_machine(pfn);
75 if (mfn != INVALID_P2M_ENTRY)
76 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
81 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
83 if (xen_feature(XENFEAT_auto_translated_physmap))
86 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
89 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
94 if (xen_feature(XENFEAT_auto_translated_physmap))
97 if (unlikely(mfn >= machine_to_phys_nr))
101 * The array access can fail (e.g., device space beyond end of RAM).
102 * In such cases it doesn't matter what we return (we return garbage),
103 * but we must handle the fault without crashing!
105 ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
112 static inline unsigned long mfn_to_pfn(unsigned long mfn)
116 if (xen_feature(XENFEAT_auto_translated_physmap))
119 pfn = mfn_to_pfn_no_overrides(mfn);
120 if (get_phys_to_machine(pfn) != mfn) {
122 * If this appears to be a foreign mfn (because the pfn
123 * doesn't map back to the mfn), then check the local override
124 * table to see if there's a better pfn to use.
126 * m2p_find_override_pfn returns ~0 if it doesn't find anything.
128 pfn = m2p_find_override_pfn(mfn, ~0);
132 * pfn is ~0 if there are no entries in the m2p for mfn or if the
133 * entry doesn't map back to the mfn and m2p_override doesn't have a
134 * valid entry for it.
137 get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
143 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
145 unsigned offset = phys.paddr & ~PAGE_MASK;
146 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
149 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
151 unsigned offset = machine.maddr & ~PAGE_MASK;
152 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
156 * We detect special mappings in one of two ways:
157 * 1. If the MFN is an I/O page then Xen will set the m2p entry
158 * to be outside our maximum possible pseudophys range.
159 * 2. If the MFN belongs to a different domain then we will certainly
160 * not have MFN in our p2m table. Conversely, if the page is ours,
161 * then we'll have p2m(m2p(MFN))==MFN.
162 * If we detect a special mapping then it doesn't have a 'struct page'.
163 * We force !pfn_valid() by returning an out-of-range pointer.
165 * NB. These checks require that, for any MFN that is not in our reservation,
166 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
167 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
168 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
170 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
171 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
172 * require. In all the cases we care about, the FOREIGN_FRAME bit is
173 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
175 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
179 if (xen_feature(XENFEAT_auto_translated_physmap))
182 pfn = mfn_to_pfn(mfn);
183 if (get_phys_to_machine(pfn) != mfn)
184 return -1; /* force !pfn_valid() */
188 /* VIRT <-> MACHINE conversion */
189 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
190 #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
191 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
192 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
194 static inline unsigned long pte_mfn(pte_t pte)
196 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
199 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
203 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
204 massage_pgprot(pgprot);
209 static inline pteval_t pte_val_ma(pte_t pte)
214 static inline pte_t __pte_ma(pteval_t x)
216 return (pte_t) { .pte = x };
219 #define pmd_val_ma(v) ((v).pmd)
220 #ifdef __PAGETABLE_PUD_FOLDED
221 #define pud_val_ma(v) ((v).pgd.pgd)
223 #define pud_val_ma(v) ((v).pud)
225 #define __pmd_ma(x) ((pmd_t) { (x) } )
227 #define pgd_val_ma(x) ((x).pgd)
229 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
231 xmaddr_t arbitrary_virt_to_machine(void *address);
232 unsigned long arbitrary_virt_to_mfn(void *vaddr);
233 void make_lowmem_page_readonly(void *vaddr);
234 void make_lowmem_page_readwrite(void *vaddr);
236 #define xen_remap(cookie, size) ioremap((cookie), (size));
237 #define xen_unmap(cookie) iounmap((cookie))
239 #endif /* _ASM_X86_XEN_PAGE_H */