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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