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 #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 unsigned long get_phys_to_machine(unsigned long pfn);
47 extern bool 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 __init 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 clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
56 struct gnttab_unmap_grant_ref *kunmap_ops,
57 struct page **pages, unsigned int count);
60 * Helper functions to write or read unsigned long values to/from
61 * memory, when the access may fault.
63 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
65 return __put_user(val, (unsigned long __user *)addr);
68 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val)
70 return __get_user(*val, (unsigned long __user *)addr);
74 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
75 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
76 * bits (identity or foreign) are set.
77 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
78 * identity or foreign indicator will be still set. __pfn_to_mfn() is
79 * encapsulating get_phys_to_machine() which is called in special cases only.
80 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
81 * cases needing an extended handling.
83 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
87 if (pfn < xen_p2m_size)
88 mfn = xen_p2m_addr[pfn];
89 else if (unlikely(pfn < xen_max_p2m_pfn))
90 return get_phys_to_machine(pfn);
92 return IDENTITY_FRAME(pfn);
94 if (unlikely(mfn == INVALID_P2M_ENTRY))
95 return get_phys_to_machine(pfn);
100 static inline unsigned long pfn_to_mfn(unsigned long pfn)
105 * Some x86 code are still using pfn_to_mfn instead of
106 * pfn_to_mfn. This will have to be removed when we figured
109 if (xen_feature(XENFEAT_auto_translated_physmap))
112 mfn = __pfn_to_mfn(pfn);
114 if (mfn != INVALID_P2M_ENTRY)
115 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
120 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
122 if (xen_feature(XENFEAT_auto_translated_physmap))
125 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
128 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
133 if (xen_feature(XENFEAT_auto_translated_physmap))
136 if (unlikely(mfn >= machine_to_phys_nr))
140 * The array access can fail (e.g., device space beyond end of RAM).
141 * In such cases it doesn't matter what we return (we return garbage),
142 * but we must handle the fault without crashing!
144 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
151 static inline unsigned long mfn_to_pfn(unsigned long mfn)
156 * Some x86 code are still using mfn_to_pfn instead of
157 * gfn_to_pfn. This will have to be removed when we figure
160 if (xen_feature(XENFEAT_auto_translated_physmap))
163 pfn = mfn_to_pfn_no_overrides(mfn);
164 if (__pfn_to_mfn(pfn) != mfn)
168 * pfn is ~0 if there are no entries in the m2p for mfn or the
169 * entry doesn't map back to the mfn.
171 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
177 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
179 unsigned offset = phys.paddr & ~PAGE_MASK;
180 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
183 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
185 unsigned offset = machine.maddr & ~PAGE_MASK;
186 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
189 /* Pseudo-physical <-> Guest conversion */
190 static inline unsigned long pfn_to_gfn(unsigned long pfn)
192 if (xen_feature(XENFEAT_auto_translated_physmap))
195 return pfn_to_mfn(pfn);
198 static inline unsigned long gfn_to_pfn(unsigned long gfn)
200 if (xen_feature(XENFEAT_auto_translated_physmap))
203 return mfn_to_pfn(gfn);
206 /* Pseudo-physical <-> Bus conversion */
207 #define pfn_to_bfn(pfn) pfn_to_gfn(pfn)
208 #define bfn_to_pfn(bfn) gfn_to_pfn(bfn)
211 * We detect special mappings in one of two ways:
212 * 1. If the MFN is an I/O page then Xen will set the m2p entry
213 * to be outside our maximum possible pseudophys range.
214 * 2. If the MFN belongs to a different domain then we will certainly
215 * not have MFN in our p2m table. Conversely, if the page is ours,
216 * then we'll have p2m(m2p(MFN))==MFN.
217 * If we detect a special mapping then it doesn't have a 'struct page'.
218 * We force !pfn_valid() by returning an out-of-range pointer.
220 * NB. These checks require that, for any MFN that is not in our reservation,
221 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
222 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
223 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
225 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
226 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
227 * require. In all the cases we care about, the FOREIGN_FRAME bit is
228 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
230 static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
234 if (xen_feature(XENFEAT_auto_translated_physmap))
237 pfn = mfn_to_pfn(mfn);
238 if (__pfn_to_mfn(pfn) != mfn)
239 return -1; /* force !pfn_valid() */
243 /* VIRT <-> MACHINE conversion */
244 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
245 #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
246 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
247 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
249 /* VIRT <-> GUEST conversion */
250 #define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v)))
251 #define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT))
253 static inline unsigned long pte_mfn(pte_t pte)
255 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
258 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
262 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
263 massage_pgprot(pgprot);
268 static inline pteval_t pte_val_ma(pte_t pte)
273 static inline pte_t __pte_ma(pteval_t x)
275 return (pte_t) { .pte = x };
278 #define pmd_val_ma(v) ((v).pmd)
279 #ifdef __PAGETABLE_PUD_FOLDED
280 #define pud_val_ma(v) ((v).pgd.pgd)
282 #define pud_val_ma(v) ((v).pud)
284 #define __pmd_ma(x) ((pmd_t) { (x) } )
286 #define pgd_val_ma(x) ((x).pgd)
288 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
290 xmaddr_t arbitrary_virt_to_machine(void *address);
291 unsigned long arbitrary_virt_to_mfn(void *vaddr);
292 void make_lowmem_page_readonly(void *vaddr);
293 void make_lowmem_page_readwrite(void *vaddr);
295 #define xen_remap(cookie, size) ioremap((cookie), (size));
296 #define xen_unmap(cookie) iounmap((cookie))
298 static inline bool xen_arch_need_swiotlb(struct device *dev,
305 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
307 return __get_free_pages(__GFP_NOWARN, order);
310 #endif /* _ASM_X86_XEN_PAGE_H */