1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_XEN_PAGE_H
3#define _ASM_X86_XEN_PAGE_H
4
5#include <linux/kernel.h>
6#include <linux/types.h>
7#include <linux/spinlock.h>
8#include <linux/pfn.h>
9#include <linux/mm.h>
10#include <linux/device.h>
11
12#include <asm/extable.h>
13#include <asm/page.h>
14#include <asm/pgtable.h>
15
16#include <xen/interface/xen.h>
17#include <xen/interface/grant_table.h>
18#include <xen/features.h>
19
20/* Xen machine address */
21typedef struct xmaddr {
22 phys_addr_t maddr;
23} xmaddr_t;
24
25/* Xen pseudo-physical address */
26typedef struct xpaddr {
27 phys_addr_t paddr;
28} xpaddr_t;
29
30#ifdef CONFIG_X86_64
31#define XEN_PHYSICAL_MASK __sme_clr((1UL << 52) - 1)
32#else
33#define XEN_PHYSICAL_MASK __PHYSICAL_MASK
34#endif
35
36#define XEN_PTE_MFN_MASK ((pteval_t)(((signed long)PAGE_MASK) & \
37 XEN_PHYSICAL_MASK))
38
39#define XMADDR(x) ((xmaddr_t) { .maddr = (x) })
40#define XPADDR(x) ((xpaddr_t) { .paddr = (x) })
41
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)
48
49#define P2M_PER_PAGE (PAGE_SIZE / sizeof(unsigned long))
50
51extern unsigned long *machine_to_phys_mapping;
52extern unsigned long machine_to_phys_nr;
53extern unsigned long *xen_p2m_addr;
54extern unsigned long xen_p2m_size;
55extern unsigned long xen_max_p2m_pfn;
56
57extern int xen_alloc_p2m_entry(unsigned long pfn);
58
59extern unsigned long get_phys_to_machine(unsigned long pfn);
60extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
61extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
62extern unsigned long __init set_phys_range_identity(unsigned long pfn_s,
63 unsigned long pfn_e);
64
65#ifdef CONFIG_XEN_PV
66extern 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);
69extern 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);
72#else
73static inline int
74set_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)
77{
78 return 0;
79}
80
81static inline int
82clear_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)
85{
86 return 0;
87}
88#endif
89
90/*
91 * Helper functions to write or read unsigned long values to/from
92 * memory, when the access may fault.
93 */
94static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
95{
96 int ret = 0;
97
98 asm volatile("1: mov %[val], %[ptr]\n"
99 "2:\n"
100 ".section .fixup, \"ax\"\n"
101 "3: sub $1, %[ret]\n"
102 " jmp 2b\n"
103 ".previous\n"
104 _ASM_EXTABLE(1b, 3b)
105 : [ret] "+r" (ret), [ptr] "=m" (*addr)
106 : [val] "r" (val));
107
108 return ret;
109}
110
111static inline int xen_safe_read_ulong(const unsigned long *addr,
112 unsigned long *val)
113{
114 int ret = 0;
115 unsigned long rval = ~0ul;
116
117 asm volatile("1: mov %[ptr], %[rval]\n"
118 "2:\n"
119 ".section .fixup, \"ax\"\n"
120 "3: sub $1, %[ret]\n"
121 " jmp 2b\n"
122 ".previous\n"
123 _ASM_EXTABLE(1b, 3b)
124 : [ret] "+r" (ret), [rval] "+r" (rval)
125 : [ptr] "m" (*addr));
126 *val = rval;
127
128 return ret;
129}
130
131#ifdef CONFIG_XEN_PV
132/*
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.
141 */
142static inline unsigned long __pfn_to_mfn(unsigned long pfn)
143{
144 unsigned long mfn;
145
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);
150 else
151 return IDENTITY_FRAME(pfn);
152
153 if (unlikely(mfn == INVALID_P2M_ENTRY))
154 return get_phys_to_machine(pfn);
155
156 return mfn;
157}
158#else
159static inline unsigned long __pfn_to_mfn(unsigned long pfn)
160{
161 return pfn;
162}
163#endif
164
165static inline unsigned long pfn_to_mfn(unsigned long pfn)
166{
167 unsigned long mfn;
168
169 /*
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
172 * out which call.
173 */
174 if (xen_feature(XENFEAT_auto_translated_physmap))
175 return pfn;
176
177 mfn = __pfn_to_mfn(pfn);
178
179 if (mfn != INVALID_P2M_ENTRY)
180 mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
181
182 return mfn;
183}
184
185static inline int phys_to_machine_mapping_valid(unsigned long pfn)
186{
187 if (xen_feature(XENFEAT_auto_translated_physmap))
188 return 1;
189
190 return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
191}
192
193static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
194{
195 unsigned long pfn;
196 int ret;
197
198 if (unlikely(mfn >= machine_to_phys_nr))
199 return ~0;
200
201 /*
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!
205 */
206 ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
207 if (ret < 0)
208 return ~0;
209
210 return pfn;
211}
212
213static inline unsigned long mfn_to_pfn(unsigned long mfn)
214{
215 unsigned long pfn;
216
217 /*
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
220 * out which call.
221 */
222 if (xen_feature(XENFEAT_auto_translated_physmap))
223 return mfn;
224
225 pfn = mfn_to_pfn_no_overrides(mfn);
226 if (__pfn_to_mfn(pfn) != mfn)
227 pfn = ~0;
228
229 /*
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.
232 */
233 if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
234 pfn = mfn;
235
236 return pfn;
237}
238
239static inline xmaddr_t phys_to_machine(xpaddr_t phys)
240{
241 unsigned offset = phys.paddr & ~PAGE_MASK;
242 return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
243}
244
245static inline xpaddr_t machine_to_phys(xmaddr_t machine)
246{
247 unsigned offset = machine.maddr & ~PAGE_MASK;
248 return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
249}
250
251/* Pseudo-physical <-> Guest conversion */
252static inline unsigned long pfn_to_gfn(unsigned long pfn)
253{
254 if (xen_feature(XENFEAT_auto_translated_physmap))
255 return pfn;
256 else
257 return pfn_to_mfn(pfn);
258}
259
260static inline unsigned long gfn_to_pfn(unsigned long gfn)
261{
262 if (xen_feature(XENFEAT_auto_translated_physmap))
263 return gfn;
264 else
265 return mfn_to_pfn(gfn);
266}
267
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)
271
272/*
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.
281 *
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.
286 *
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.
291 */
292static inline unsigned long bfn_to_local_pfn(unsigned long mfn)
293{
294 unsigned long pfn;
295
296 if (xen_feature(XENFEAT_auto_translated_physmap))
297 return mfn;
298
299 pfn = mfn_to_pfn(mfn);
300 if (__pfn_to_mfn(pfn) != mfn)
301 return -1; /* force !pfn_valid() */
302 return pfn;
303}
304
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))
310
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))
314
315static inline unsigned long pte_mfn(pte_t pte)
316{
317 return (pte.pte & XEN_PTE_MFN_MASK) >> PAGE_SHIFT;
318}
319
320static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
321{
322 pte_t pte;
323
324 pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
325 massage_pgprot(pgprot);
326
327 return pte;
328}
329
330static inline pteval_t pte_val_ma(pte_t pte)
331{
332 return pte.pte;
333}
334
335static inline pte_t __pte_ma(pteval_t x)
336{
337 return (pte_t) { .pte = x };
338}
339
340#define pmd_val_ma(v) ((v).pmd)
341#ifdef __PAGETABLE_PUD_FOLDED
342#define pud_val_ma(v) ((v).p4d.pgd.pgd)
343#else
344#define pud_val_ma(v) ((v).pud)
345#endif
346#define __pmd_ma(x) ((pmd_t) { (x) } )
347
348#ifdef __PAGETABLE_P4D_FOLDED
349#define p4d_val_ma(x) ((x).pgd.pgd)
350#else
351#define p4d_val_ma(x) ((x).p4d)
352#endif
353
354xmaddr_t arbitrary_virt_to_machine(void *address);
355unsigned long arbitrary_virt_to_mfn(void *vaddr);
356void make_lowmem_page_readonly(void *vaddr);
357void make_lowmem_page_readwrite(void *vaddr);
358
359#define xen_remap(cookie, size) ioremap((cookie), (size));
360#define xen_unmap(cookie) iounmap((cookie))
361
362static inline bool xen_arch_need_swiotlb(struct device *dev,
363 phys_addr_t phys,
364 dma_addr_t dev_addr)
365{
366 return false;
367}
368
369static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order)
370{
371 return __get_free_pages(__GFP_NOWARN, order);
372}
373
374#endif /* _ASM_X86_XEN_PAGE_H */
375