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 extern unsigned long *machine_to_phys_mapping;
39 extern unsigned long machine_to_phys_nr;
40 extern unsigned long *xen_p2m_addr;
41 extern unsigned long xen_p2m_size;
42 extern unsigned long xen_max_p2m_pfn;
44 extern unsigned long get_phys_to_machine(unsigned long pfn);
45 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
46 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
47 extern unsigned long set_phys_range_identity(unsigned long pfn_s,
50 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
51 struct gnttab_map_grant_ref *kmap_ops,
52 struct page **pages, unsigned int count);
53 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
54 struct gnttab_unmap_grant_ref *kunmap_ops,
55 struct page **pages, unsigned int count);
58 * Helper functions to write or read unsigned long values to/from
59 * memory, when the access may fault.
61 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
63 return __put_user(val, (unsigned long __user *)addr);
66 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val)
68 return __get_user(*val, (unsigned long __user *)addr);
72 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
73 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
74 * bits (identity or foreign) are set.
75 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
76 * identity or foreign indicator will be still set. __pfn_to_mfn() is
77 * encapsulating get_phys_to_machine() which is called in special cases only.
78 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
79 * cases needing an extended handling.
81 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
85 if (pfn < xen_p2m_size)
86 mfn = xen_p2m_addr[pfn];
87 else if (unlikely(pfn < xen_max_p2m_pfn))
88 return get_phys_to_machine(pfn);
90 return IDENTITY_FRAME(pfn);
92 if (unlikely(mfn == INVALID_P2M_ENTRY))
93 return get_phys_to_machine(pfn);
98 static inline unsigned long pfn_to_mfn(unsigned long pfn)
102 if (xen_feature(XENFEAT_auto_translated_physmap))
105 mfn = __pfn_to_mfn(pfn);
107 if (mfn != INVALID_P2M_ENTRY)
108 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
113 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
115 if (xen_feature(XENFEAT_auto_translated_physmap))
118 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
121 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
126 if (xen_feature(XENFEAT_auto_translated_physmap))
129 if (unlikely(mfn >= machine_to_phys_nr))
133 * The array access can fail (e.g., device space beyond end of RAM).
134 * In such cases it doesn't matter what we return (we return garbage),
135 * but we must handle the fault without crashing!
137 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
144 static inline unsigned long mfn_to_pfn(unsigned long mfn)
148 if (xen_feature(XENFEAT_auto_translated_physmap))
151 pfn = mfn_to_pfn_no_overrides(mfn);
152 if (__pfn_to_mfn(pfn) != mfn)
156 * pfn is ~0 if there are no entries in the m2p for mfn or the
157 * entry doesn't map back to the mfn.
159 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
165 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
167 unsigned offset = phys.paddr & ~PAGE_MASK;
168 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
171 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
173 unsigned offset = machine.maddr & ~PAGE_MASK;
174 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
178 * We detect special mappings in one of two ways:
179 * 1. If the MFN is an I/O page then Xen will set the m2p entry
180 * to be outside our maximum possible pseudophys range.
181 * 2. If the MFN belongs to a different domain then we will certainly
182 * not have MFN in our p2m table. Conversely, if the page is ours,
183 * then we'll have p2m(m2p(MFN))==MFN.
184 * If we detect a special mapping then it doesn't have a 'struct page'.
185 * We force !pfn_valid() by returning an out-of-range pointer.
187 * NB. These checks require that, for any MFN that is not in our reservation,
188 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
189 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
190 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
192 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
193 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
194 * require. In all the cases we care about, the FOREIGN_FRAME bit is
195 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
197 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
201 if (xen_feature(XENFEAT_auto_translated_physmap))
204 pfn = mfn_to_pfn(mfn);
205 if (__pfn_to_mfn(pfn) != mfn)
206 return -1; /* force !pfn_valid() */
210 /* VIRT <-> MACHINE conversion */
211 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
212 #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
213 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
214 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
216 static inline unsigned long pte_mfn(pte_t pte)
218 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
221 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
225 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
226 massage_pgprot(pgprot);
231 static inline pteval_t pte_val_ma(pte_t pte)
236 static inline pte_t __pte_ma(pteval_t x)
238 return (pte_t) { .pte = x };
241 #define pmd_val_ma(v) ((v).pmd)
242 #ifdef __PAGETABLE_PUD_FOLDED
243 #define pud_val_ma(v) ((v).pgd.pgd)
245 #define pud_val_ma(v) ((v).pud)
247 #define __pmd_ma(x) ((pmd_t) { (x) } )
249 #define pgd_val_ma(x) ((x).pgd)
251 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
253 xmaddr_t arbitrary_virt_to_machine(void *address);
254 unsigned long arbitrary_virt_to_mfn(void *vaddr);
255 void make_lowmem_page_readonly(void *vaddr);
256 void make_lowmem_page_readwrite(void *vaddr);
258 #define xen_remap(cookie, size) ioremap((cookie), (size));
259 #define xen_unmap(cookie) iounmap((cookie))
261 static inline bool xen_arch_need_swiotlb(struct device *dev,
268 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
270 return __get_free_pages(__GFP_NOWARN, order);
273 #endif /* _ASM_X86_XEN_PAGE_H */