1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_XEN_PAGE_H
3 #define _ASM_X86_XEN_PAGE_H
5 #include <linux/kernel.h>
6 #include <linux/types.h>
7 #include <linux/spinlock.h>
10 #include <linux/device.h>
12 #include <asm/extable.h>
14 #include <asm/pgtable.h>
16 #include <xen/interface/xen.h>
17 #include <xen/interface/grant_table.h>
18 #include <xen/features.h>
20 /* Xen machine address */
21 typedef struct xmaddr
{
25 /* Xen pseudo-physical address */
26 typedef struct xpaddr
{
31 #define XEN_PHYSICAL_MASK __sme_clr((1UL << 52) - 1)
33 #define XEN_PHYSICAL_MASK __PHYSICAL_MASK
36 #define XEN_PTE_MFN_MASK ((pteval_t)(((signed long)PAGE_MASK) & \
39 #define XMADDR(x) ((xmaddr_t) { .maddr = (x) })
40 #define XPADDR(x) ((xpaddr_t) { .paddr = (x) })
42 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
43 #define INVALID_P2M_ENTRY (~0UL)
44 #define FOREIGN_FRAME_BIT (1UL<<(BITS_PER_LONG-1))
45 #define IDENTITY_FRAME_BIT (1UL<<(BITS_PER_LONG-2))
46 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT)
47 #define IDENTITY_FRAME(m) ((m) | IDENTITY_FRAME_BIT)
49 #define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
51 extern unsigned long *machine_to_phys_mapping
;
52 extern unsigned long machine_to_phys_nr
;
53 extern unsigned long *xen_p2m_addr
;
54 extern unsigned long xen_p2m_size
;
55 extern unsigned long xen_max_p2m_pfn
;
57 extern int xen_alloc_p2m_entry(unsigned long pfn
);
59 extern unsigned long get_phys_to_machine(unsigned long pfn
);
60 extern bool set_phys_to_machine(unsigned long pfn
, unsigned long mfn
);
61 extern bool __set_phys_to_machine(unsigned long pfn
, unsigned long mfn
);
62 extern unsigned long __init
set_phys_range_identity(unsigned long pfn_s
,
66 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref
*map_ops
,
67 struct gnttab_map_grant_ref
*kmap_ops
,
68 struct page
**pages
, unsigned int count
);
69 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref
*unmap_ops
,
70 struct gnttab_unmap_grant_ref
*kunmap_ops
,
71 struct page
**pages
, unsigned int count
);
74 set_foreign_p2m_mapping(struct gnttab_map_grant_ref
*map_ops
,
75 struct gnttab_map_grant_ref
*kmap_ops
,
76 struct page
**pages
, unsigned int count
)
82 clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref
*unmap_ops
,
83 struct gnttab_unmap_grant_ref
*kunmap_ops
,
84 struct page
**pages
, unsigned int count
)
91 * Helper functions to write or read unsigned long values to/from
92 * memory, when the access may fault.
94 static inline int xen_safe_write_ulong(unsigned long *addr
, unsigned long val
)
98 asm volatile("1: mov %[val], %[ptr]\n"
100 ".section .fixup, \"ax\"\n"
101 "3: sub $1, %[ret]\n"
105 : [ret
] "+r" (ret
), [ptr
] "=m" (*addr
)
111 static inline int xen_safe_read_ulong(const unsigned long *addr
,
115 unsigned long rval
= ~0ul;
117 asm volatile("1: mov %[ptr], %[rval]\n"
119 ".section .fixup, \"ax\"\n"
120 "3: sub $1, %[ret]\n"
124 : [ret
] "+r" (ret
), [rval
] "+r" (rval
)
125 : [ptr
] "m" (*addr
));
133 * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
134 * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
135 * bits (identity or foreign) are set.
136 * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
137 * identity or foreign indicator will be still set. __pfn_to_mfn() is
138 * encapsulating get_phys_to_machine() which is called in special cases only.
139 * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
140 * cases needing an extended handling.
142 static inline unsigned long __pfn_to_mfn(unsigned long pfn
)
146 if (pfn
< xen_p2m_size
)
147 mfn
= xen_p2m_addr
[pfn
];
148 else if (unlikely(pfn
< xen_max_p2m_pfn
))
149 return get_phys_to_machine(pfn
);
151 return IDENTITY_FRAME(pfn
);
153 if (unlikely(mfn
== INVALID_P2M_ENTRY
))
154 return get_phys_to_machine(pfn
);
159 static inline unsigned long __pfn_to_mfn(unsigned long pfn
)
165 static inline unsigned long pfn_to_mfn(unsigned long pfn
)
170 * Some x86 code are still using pfn_to_mfn instead of
171 * pfn_to_mfn. This will have to be removed when we figured
174 if (xen_feature(XENFEAT_auto_translated_physmap
))
177 mfn
= __pfn_to_mfn(pfn
);
179 if (mfn
!= INVALID_P2M_ENTRY
)
180 mfn
&= ~(FOREIGN_FRAME_BIT
| IDENTITY_FRAME_BIT
);
185 static inline int phys_to_machine_mapping_valid(unsigned long pfn
)
187 if (xen_feature(XENFEAT_auto_translated_physmap
))
190 return __pfn_to_mfn(pfn
) != INVALID_P2M_ENTRY
;
193 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn
)
198 if (unlikely(mfn
>= machine_to_phys_nr
))
202 * The array access can fail (e.g., device space beyond end of RAM).
203 * In such cases it doesn't matter what we return (we return garbage),
204 * but we must handle the fault without crashing!
206 ret
= xen_safe_read_ulong(&machine_to_phys_mapping
[mfn
], &pfn
);
213 static inline unsigned long mfn_to_pfn(unsigned long mfn
)
218 * Some x86 code are still using mfn_to_pfn instead of
219 * gfn_to_pfn. This will have to be removed when we figure
222 if (xen_feature(XENFEAT_auto_translated_physmap
))
225 pfn
= mfn_to_pfn_no_overrides(mfn
);
226 if (__pfn_to_mfn(pfn
) != mfn
)
230 * pfn is ~0 if there are no entries in the m2p for mfn or the
231 * entry doesn't map back to the mfn.
233 if (pfn
== ~0 && __pfn_to_mfn(mfn
) == IDENTITY_FRAME(mfn
))
239 static inline xmaddr_t
phys_to_machine(xpaddr_t phys
)
241 unsigned offset
= phys
.paddr
& ~PAGE_MASK
;
242 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys
.paddr
))) | offset
);
245 static inline xpaddr_t
machine_to_phys(xmaddr_t machine
)
247 unsigned offset
= machine
.maddr
& ~PAGE_MASK
;
248 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine
.maddr
))) | offset
);
251 /* Pseudo-physical <-> Guest conversion */
252 static inline unsigned long pfn_to_gfn(unsigned long pfn
)
254 if (xen_feature(XENFEAT_auto_translated_physmap
))
257 return pfn_to_mfn(pfn
);
260 static inline unsigned long gfn_to_pfn(unsigned long gfn
)
262 if (xen_feature(XENFEAT_auto_translated_physmap
))
265 return mfn_to_pfn(gfn
);
268 /* Pseudo-physical <-> Bus conversion */
269 #define pfn_to_bfn(pfn) pfn_to_gfn(pfn)
270 #define bfn_to_pfn(bfn) gfn_to_pfn(bfn)
273 * We detect special mappings in one of two ways:
274 * 1. If the MFN is an I/O page then Xen will set the m2p entry
275 * to be outside our maximum possible pseudophys range.
276 * 2. If the MFN belongs to a different domain then we will certainly
277 * not have MFN in our p2m table. Conversely, if the page is ours,
278 * then we'll have p2m(m2p(MFN))==MFN.
279 * If we detect a special mapping then it doesn't have a 'struct page'.
280 * We force !pfn_valid() by returning an out-of-range pointer.
282 * NB. These checks require that, for any MFN that is not in our reservation,
283 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
284 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
285 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
287 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
288 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
289 * require. In all the cases we care about, the FOREIGN_FRAME bit is
290 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
292 static inline unsigned long bfn_to_local_pfn(unsigned long mfn
)
296 if (xen_feature(XENFEAT_auto_translated_physmap
))
299 pfn
= mfn_to_pfn(mfn
);
300 if (__pfn_to_mfn(pfn
) != mfn
)
301 return -1; /* force !pfn_valid() */
305 /* VIRT <-> MACHINE conversion */
306 #define virt_to_machine(v) (phys_to_machine(XPADDR(__pa(v))))
307 #define virt_to_pfn(v) (PFN_DOWN(__pa(v)))
308 #define virt_to_mfn(v) (pfn_to_mfn(virt_to_pfn(v)))
309 #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT))
311 /* VIRT <-> GUEST conversion */
312 #define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v)))
313 #define gfn_to_virt(g) (__va(gfn_to_pfn(g) << PAGE_SHIFT))
315 static inline unsigned long pte_mfn(pte_t pte
)
317 return (pte
.pte
& XEN_PTE_MFN_MASK
) >> PAGE_SHIFT
;
320 static inline pte_t
mfn_pte(unsigned long page_nr
, pgprot_t pgprot
)
324 pte
.pte
= ((phys_addr_t
)page_nr
<< PAGE_SHIFT
) |
325 massage_pgprot(pgprot
);
330 static inline pteval_t
pte_val_ma(pte_t pte
)
335 static inline pte_t
__pte_ma(pteval_t x
)
337 return (pte_t
) { .pte
= x
};
340 #define pmd_val_ma(v) ((v).pmd)
341 #ifdef __PAGETABLE_PUD_FOLDED
342 #define pud_val_ma(v) ((v).p4d.pgd.pgd)
344 #define pud_val_ma(v) ((v).pud)
346 #define __pmd_ma(x) ((pmd_t) { (x) } )
348 #ifdef __PAGETABLE_P4D_FOLDED
349 #define p4d_val_ma(x) ((x).pgd.pgd)
351 #define p4d_val_ma(x) ((x).p4d)
354 xmaddr_t
arbitrary_virt_to_machine(void *address
);
355 unsigned long arbitrary_virt_to_mfn(void *vaddr
);
356 void make_lowmem_page_readonly(void *vaddr
);
357 void make_lowmem_page_readwrite(void *vaddr
);
359 #define xen_remap(cookie, size) ioremap((cookie), (size));
360 #define xen_unmap(cookie) iounmap((cookie))
362 static inline bool xen_arch_need_swiotlb(struct device
*dev
,
369 static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order
)
371 return __get_free_pages(__GFP_NOWARN
, order
);
374 #endif /* _ASM_X86_XEN_PAGE_H */