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/interface/grant_table.h>
16 #include <xen/features.h>
17
18 /* Xen machine address */
19 typedef struct xmaddr {
20 phys_addr_t maddr;
21 } xmaddr_t;
22
23 /* Xen pseudo-physical address */
24 typedef 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 #define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
39
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;
45
46 extern int xen_alloc_p2m_entry(unsigned long pfn);
47
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,
52 unsigned long pfn_e);
53
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);
60
61 /*
62 * Helper functions to write or read unsigned long values to/from
63 * memory, when the access may fault.
64 */
xen_safe_write_ulong(unsigned long * addr,unsigned long val)65 static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
66 {
67 return __put_user(val, (unsigned long __user *)addr);
68 }
69
xen_safe_read_ulong(unsigned long * addr,unsigned long * val)70 static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val)
71 {
72 return __get_user(*val, (unsigned long __user *)addr);
73 }
74
75 /*
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.
84 */
__pfn_to_mfn(unsigned long pfn)85 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
86 {
87 unsigned long mfn;
88
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);
93 else
94 return IDENTITY_FRAME(pfn);
95
96 if (unlikely(mfn == INVALID_P2M_ENTRY))
97 return get_phys_to_machine(pfn);
98
99 return mfn;
100 }
101
pfn_to_mfn(unsigned long pfn)102 static inline unsigned long pfn_to_mfn(unsigned long pfn)
103 {
104 unsigned long mfn;
105
106 /*
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
109 * out which call.
110 */
111 if (xen_feature(XENFEAT_auto_translated_physmap))
112 return pfn;
113
114 mfn = __pfn_to_mfn(pfn);
115
116 if (mfn != INVALID_P2M_ENTRY)
117 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
118
119 return mfn;
120 }
121
phys_to_machine_mapping_valid(unsigned long pfn)122 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
123 {
124 if (xen_feature(XENFEAT_auto_translated_physmap))
125 return 1;
126
127 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
128 }
129
mfn_to_pfn_no_overrides(unsigned long mfn)130 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
131 {
132 unsigned long pfn;
133 int ret;
134
135 if (xen_feature(XENFEAT_auto_translated_physmap))
136 return mfn;
137
138 if (unlikely(mfn >= machine_to_phys_nr))
139 return ~0;
140
141 /*
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!
145 */
146 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
147 if (ret < 0)
148 return ~0;
149
150 return pfn;
151 }
152
mfn_to_pfn(unsigned long mfn)153 static inline unsigned long mfn_to_pfn(unsigned long mfn)
154 {
155 unsigned long pfn;
156
157 /*
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
160 * out which call.
161 */
162 if (xen_feature(XENFEAT_auto_translated_physmap))
163 return mfn;
164
165 pfn = mfn_to_pfn_no_overrides(mfn);
166 if (__pfn_to_mfn(pfn) != mfn)
167 pfn = ~0;
168
169 /*
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.
172 */
173 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
174 pfn = mfn;
175
176 return pfn;
177 }
178
phys_to_machine(xpaddr_t phys)179 static inline xmaddr_t phys_to_machine(xpaddr_t phys)
180 {
181 unsigned offset = phys.paddr & ~PAGE_MASK;
182 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
183 }
184
machine_to_phys(xmaddr_t machine)185 static inline xpaddr_t machine_to_phys(xmaddr_t machine)
186 {
187 unsigned offset = machine.maddr & ~PAGE_MASK;
188 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
189 }
190
191 /* Pseudo-physical <-> Guest conversion */
pfn_to_gfn(unsigned long pfn)192 static inline unsigned long pfn_to_gfn(unsigned long pfn)
193 {
194 if (xen_feature(XENFEAT_auto_translated_physmap))
195 return pfn;
196 else
197 return pfn_to_mfn(pfn);
198 }
199
gfn_to_pfn(unsigned long gfn)200 static inline unsigned long gfn_to_pfn(unsigned long gfn)
201 {
202 if (xen_feature(XENFEAT_auto_translated_physmap))
203 return gfn;
204 else
205 return mfn_to_pfn(gfn);
206 }
207
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)
211
212 /*
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.
221 *
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.
226 *
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.
231 */
bfn_to_local_pfn(unsigned long mfn)232 static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
233 {
234 unsigned long pfn;
235
236 if (xen_feature(XENFEAT_auto_translated_physmap))
237 return mfn;
238
239 pfn = mfn_to_pfn(mfn);
240 if (__pfn_to_mfn(pfn) != mfn)
241 return -1; /* force !pfn_valid() */
242 return pfn;
243 }
244
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))
250
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))
254
pte_mfn(pte_t pte)255 static inline unsigned long pte_mfn(pte_t pte)
256 {
257 return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
258 }
259
mfn_pte(unsigned long page_nr,pgprot_t pgprot)260 static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
261 {
262 pte_t pte;
263
264 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
265 massage_pgprot(pgprot);
266
267 return pte;
268 }
269
pte_val_ma(pte_t pte)270 static inline pteval_t pte_val_ma(pte_t pte)
271 {
272 return pte.pte;
273 }
274
__pte_ma(pteval_t x)275 static inline pte_t __pte_ma(pteval_t x)
276 {
277 return (pte_t) { .pte = x };
278 }
279
280 #define pmd_val_ma(v) ((v).pmd)
281 #ifdef __PAGETABLE_PUD_FOLDED
282 #define pud_val_ma(v) ((v).pgd.pgd)
283 #else
284 #define pud_val_ma(v) ((v).pud)
285 #endif
286 #define __pmd_ma(x) ((pmd_t) { (x) } )
287
288 #define pgd_val_ma(x) ((x).pgd)
289
290 void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
291
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);
296
297 #define xen_remap(cookie, size) ioremap((cookie), (size));
298 #define xen_unmap(cookie) iounmap((cookie))
299
xen_arch_need_swiotlb(struct device * dev,phys_addr_t phys,dma_addr_t dev_addr)300 static inline bool xen_arch_need_swiotlb(struct device *dev,
301 phys_addr_t phys,
302 dma_addr_t dev_addr)
303 {
304 return false;
305 }
306
xen_get_swiotlb_free_pages(unsigned int order)307 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
308 {
309 return __get_free_pages(__GFP_NOWARN, order);
310 }
311
312 #endif /* _ASM_X86_XEN_PAGE_H */
313