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/interface/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 #define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
40 extern unsigned long *machine_to_phys_mapping;
41 extern unsigned long machine_to_phys_nr;
42 extern unsigned long *xen_p2m_addr;
43 extern unsigned long xen_p2m_size;
44 extern unsigned long xen_max_p2m_pfn;
46 extern int xen_alloc_p2m_entry(unsigned long pfn);
48 extern unsigned long get_phys_to_machine(unsigned long pfn);
49 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
50 extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
51 extern unsigned long __init set_phys_range_identity(unsigned long pfn_s,
54 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
55 struct gnttab_map_grant_ref *kmap_ops,
56 struct page **pages, unsigned int count);
57 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
58 struct gnttab_unmap_grant_ref *kunmap_ops,
59 struct page **pages, unsigned int count);
62 * Helper functions to write or read unsigned long values to/from
63 * memory, when the access may fault.
65 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
67 return __put_user(val, (unsigned long __user *)addr);
70 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val)
72 return __get_user(*val, (unsigned long __user *)addr);
76 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
77 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
78 * bits (identity or foreign) are set.
79 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
80 * identity or foreign indicator will be still set. __pfn_to_mfn() is
81 * encapsulating get_phys_to_machine() which is called in special cases only.
82 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
83 * cases needing an extended handling.
85 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
89 if (pfn < xen_p2m_size)
90 mfn = xen_p2m_addr[pfn];
91 else if (unlikely(pfn < xen_max_p2m_pfn))
92 return get_phys_to_machine(pfn);
94 return IDENTITY_FRAME(pfn);
96 if (unlikely(mfn == INVALID_P2M_ENTRY))
97 return get_phys_to_machine(pfn);
102 static inline unsigned long pfn_to_mfn(unsigned long pfn)
107 * Some x86 code are still using pfn_to_mfn instead of
108 * pfn_to_mfn. This will have to be removed when we figured
111 if (xen_feature(XENFEAT_auto_translated_physmap))
114 mfn = __pfn_to_mfn(pfn);
116 if (mfn != INVALID_P2M_ENTRY)
117 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
122 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
124 if (xen_feature(XENFEAT_auto_translated_physmap))
127 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
130 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
135 if (xen_feature(XENFEAT_auto_translated_physmap))
138 if (unlikely(mfn >= machine_to_phys_nr))
142 * The array access can fail (e.g., device space beyond end of RAM).
143 * In such cases it doesn't matter what we return (we return garbage),
144 * but we must handle the fault without crashing!
146 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
153 static inline unsigned long mfn_to_pfn(unsigned long mfn)
158 * Some x86 code are still using mfn_to_pfn instead of
159 * gfn_to_pfn. This will have to be removed when we figure
162 if (xen_feature(XENFEAT_auto_translated_physmap))
165 pfn = mfn_to_pfn_no_overrides(mfn);
166 if (__pfn_to_mfn(pfn) != mfn)
170 * pfn is ~0 if there are no entries in the m2p for mfn or the
171 * entry doesn't map back to the mfn.
173 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
179 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
181 unsigned offset = phys.paddr & ~PAGE_MASK;
182 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
185 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
187 unsigned offset = machine.maddr & ~PAGE_MASK;
188 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
191 /* Pseudo-physical <-> Guest conversion */
192 static inline unsigned long pfn_to_gfn(unsigned long pfn)
194 if (xen_feature(XENFEAT_auto_translated_physmap))
197 return pfn_to_mfn(pfn);
200 static inline unsigned long gfn_to_pfn(unsigned long gfn)
202 if (xen_feature(XENFEAT_auto_translated_physmap))
205 return mfn_to_pfn(gfn);
208 /* Pseudo-physical <-> Bus conversion */
209 #define pfn_to_bfn(pfn) pfn_to_gfn(pfn)
210 #define bfn_to_pfn(bfn) gfn_to_pfn(bfn)
213 * We detect special mappings in one of two ways:
214 * 1. If the MFN is an I/O page then Xen will set the m2p entry
215 * to be outside our maximum possible pseudophys range.
216 * 2. If the MFN belongs to a different domain then we will certainly
217 * not have MFN in our p2m table. Conversely, if the page is ours,
218 * then we'll have p2m(m2p(MFN))==MFN.
219 * If we detect a special mapping then it doesn't have a 'struct page'.
220 * We force !pfn_valid() by returning an out-of-range pointer.
222 * NB. These checks require that, for any MFN that is not in our reservation,
223 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
224 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
225 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
227 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
228 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
229 * require. In all the cases we care about, the FOREIGN_FRAME bit is
230 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
232 static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
236 if (xen_feature(XENFEAT_auto_translated_physmap))
239 pfn = mfn_to_pfn(mfn);
240 if (__pfn_to_mfn(pfn) != mfn)
241 return -1; /* force !pfn_valid() */
245 /* VIRT <-> MACHINE conversion */
246 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
247 #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
248 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
249 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
251 /* VIRT <-> GUEST conversion */
252 #define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v)))
253 #define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT))
255 static inline unsigned long pte_mfn(pte_t pte)
257 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
260 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
264 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
265 massage_pgprot(pgprot);
270 static inline pteval_t pte_val_ma(pte_t pte)
275 static inline pte_t __pte_ma(pteval_t x)
277 return (pte_t) { .pte = x };
280 #define pmd_val_ma(v) ((v).pmd)
281 #ifdef __PAGETABLE_PUD_FOLDED
282 #define pud_val_ma(v) ((v).pgd.pgd)
284 #define pud_val_ma(v) ((v).pud)
286 #define __pmd_ma(x) ((pmd_t) { (x) } )
288 #define pgd_val_ma(x) ((x).pgd)
290 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
292 xmaddr_t arbitrary_virt_to_machine(void *address);
293 unsigned long arbitrary_virt_to_mfn(void *vaddr);
294 void make_lowmem_page_readonly(void *vaddr);
295 void make_lowmem_page_readwrite(void *vaddr);
297 #define xen_remap(cookie, size) ioremap((cookie), (size));
298 #define xen_unmap(cookie) iounmap((cookie))
300 static inline bool xen_arch_need_swiotlb(struct device *dev,
307 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
309 return __get_free_pages(__GFP_NOWARN, order);
312 #endif /* _ASM_X86_XEN_PAGE_H */