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 */
19typedef struct xmaddr {
20	phys_addr_t maddr;
21} xmaddr_t;
22
23/* Xen pseudo-physical address */
24typedef 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
40extern unsigned long *machine_to_phys_mapping;
41extern unsigned long  machine_to_phys_nr;
42extern unsigned long *xen_p2m_addr;
43extern unsigned long  xen_p2m_size;
44extern unsigned long  xen_max_p2m_pfn;
45
46extern int xen_alloc_p2m_entry(unsigned long pfn);
47
48extern unsigned long get_phys_to_machine(unsigned long pfn);
49extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
50extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
51extern unsigned long __init set_phys_range_identity(unsigned long pfn_s,
52						    unsigned long pfn_e);
53
54extern 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);
57extern 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 */
65static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
66{
67	return __put_user(val, (unsigned long __user *)addr);
68}
69
70static 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 */
85static 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
102static 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
122static 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
130static 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
153static 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
179static 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
185static 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 */
192static 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
200static 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 */
232static 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
255static inline unsigned long pte_mfn(pte_t pte)
256{
257	return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
258}
259
260static 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
270static inline pteval_t pte_val_ma(pte_t pte)
271{
272	return pte.pte;
273}
274
275static 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
290void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
291
292xmaddr_t arbitrary_virt_to_machine(void *address);
293unsigned long arbitrary_virt_to_mfn(void *vaddr);
294void make_lowmem_page_readonly(void *vaddr);
295void make_lowmem_page_readwrite(void *vaddr);
296
297#define xen_remap(cookie, size) ioremap((cookie), (size));
298#define xen_unmap(cookie) iounmap((cookie))
299
300static 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
307static 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