Merge tag 'asm-generic-timers-5.11' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-microblaze.git] / drivers / xen / grant-table.c
1 /******************************************************************************
2  * grant_table.c
3  *
4  * Granting foreign access to our memory reservation.
5  *
6  * Copyright (c) 2005-2006, Christopher Clark
7  * Copyright (c) 2004-2005, K A Fraser
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License version 2
11  * as published by the Free Software Foundation; or, when distributed
12  * separately from the Linux kernel or incorporated into other
13  * software packages, subject to the following license:
14  *
15  * Permission is hereby granted, free of charge, to any person obtaining a copy
16  * of this source file (the "Software"), to deal in the Software without
17  * restriction, including without limitation the rights to use, copy, modify,
18  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19  * and to permit persons to whom the Software is furnished to do so, subject to
20  * the following conditions:
21  *
22  * The above copyright notice and this permission notice shall be included in
23  * all copies or substantial portions of the Software.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31  * IN THE SOFTWARE.
32  */
33
34 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
35
36 #include <linux/memblock.h>
37 #include <linux/sched.h>
38 #include <linux/mm.h>
39 #include <linux/slab.h>
40 #include <linux/vmalloc.h>
41 #include <linux/uaccess.h>
42 #include <linux/io.h>
43 #include <linux/delay.h>
44 #include <linux/hardirq.h>
45 #include <linux/workqueue.h>
46 #include <linux/ratelimit.h>
47 #include <linux/moduleparam.h>
48 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
49 #include <linux/dma-mapping.h>
50 #endif
51
52 #include <xen/xen.h>
53 #include <xen/interface/xen.h>
54 #include <xen/page.h>
55 #include <xen/grant_table.h>
56 #include <xen/interface/memory.h>
57 #include <xen/hvc-console.h>
58 #include <xen/swiotlb-xen.h>
59 #include <xen/balloon.h>
60 #ifdef CONFIG_X86
61 #include <asm/xen/cpuid.h>
62 #endif
63 #include <xen/mem-reservation.h>
64 #include <asm/xen/hypercall.h>
65 #include <asm/xen/interface.h>
66
67 #include <asm/sync_bitops.h>
68
69 /* External tools reserve first few grant table entries. */
70 #define NR_RESERVED_ENTRIES 8
71 #define GNTTAB_LIST_END 0xffffffff
72
73 static grant_ref_t **gnttab_list;
74 static unsigned int nr_grant_frames;
75 static int gnttab_free_count;
76 static grant_ref_t gnttab_free_head;
77 static DEFINE_SPINLOCK(gnttab_list_lock);
78 struct grant_frames xen_auto_xlat_grant_frames;
79 static unsigned int xen_gnttab_version;
80 module_param_named(version, xen_gnttab_version, uint, 0);
81
82 static union {
83         struct grant_entry_v1 *v1;
84         union grant_entry_v2 *v2;
85         void *addr;
86 } gnttab_shared;
87
88 /*This is a structure of function pointers for grant table*/
89 struct gnttab_ops {
90         /*
91          * Version of the grant interface.
92          */
93         unsigned int version;
94         /*
95          * Grant refs per grant frame.
96          */
97         unsigned int grefs_per_grant_frame;
98         /*
99          * Mapping a list of frames for storing grant entries. Frames parameter
100          * is used to store grant table address when grant table being setup,
101          * nr_gframes is the number of frames to map grant table. Returning
102          * GNTST_okay means success and negative value means failure.
103          */
104         int (*map_frames)(xen_pfn_t *frames, unsigned int nr_gframes);
105         /*
106          * Release a list of frames which are mapped in map_frames for grant
107          * entry status.
108          */
109         void (*unmap_frames)(void);
110         /*
111          * Introducing a valid entry into the grant table, granting the frame of
112          * this grant entry to domain for accessing or transfering. Ref
113          * parameter is reference of this introduced grant entry, domid is id of
114          * granted domain, frame is the page frame to be granted, and flags is
115          * status of the grant entry to be updated.
116          */
117         void (*update_entry)(grant_ref_t ref, domid_t domid,
118                              unsigned long frame, unsigned flags);
119         /*
120          * Stop granting a grant entry to domain for accessing. Ref parameter is
121          * reference of a grant entry whose grant access will be stopped,
122          * readonly is not in use in this function. If the grant entry is
123          * currently mapped for reading or writing, just return failure(==0)
124          * directly and don't tear down the grant access. Otherwise, stop grant
125          * access for this entry and return success(==1).
126          */
127         int (*end_foreign_access_ref)(grant_ref_t ref, int readonly);
128         /*
129          * Stop granting a grant entry to domain for transfer. Ref parameter is
130          * reference of a grant entry whose grant transfer will be stopped. If
131          * tranfer has not started, just reclaim the grant entry and return
132          * failure(==0). Otherwise, wait for the transfer to complete and then
133          * return the frame.
134          */
135         unsigned long (*end_foreign_transfer_ref)(grant_ref_t ref);
136         /*
137          * Query the status of a grant entry. Ref parameter is reference of
138          * queried grant entry, return value is the status of queried entry.
139          * Detailed status(writing/reading) can be gotten from the return value
140          * by bit operations.
141          */
142         int (*query_foreign_access)(grant_ref_t ref);
143 };
144
145 struct unmap_refs_callback_data {
146         struct completion completion;
147         int result;
148 };
149
150 static const struct gnttab_ops *gnttab_interface;
151
152 /* This reflects status of grant entries, so act as a global value. */
153 static grant_status_t *grstatus;
154
155 static struct gnttab_free_callback *gnttab_free_callback_list;
156
157 static int gnttab_expand(unsigned int req_entries);
158
159 #define RPP (PAGE_SIZE / sizeof(grant_ref_t))
160 #define SPP (PAGE_SIZE / sizeof(grant_status_t))
161
162 static inline grant_ref_t *__gnttab_entry(grant_ref_t entry)
163 {
164         return &gnttab_list[(entry) / RPP][(entry) % RPP];
165 }
166 /* This can be used as an l-value */
167 #define gnttab_entry(entry) (*__gnttab_entry(entry))
168
169 static int get_free_entries(unsigned count)
170 {
171         unsigned long flags;
172         int ref, rc = 0;
173         grant_ref_t head;
174
175         spin_lock_irqsave(&gnttab_list_lock, flags);
176
177         if ((gnttab_free_count < count) &&
178             ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) {
179                 spin_unlock_irqrestore(&gnttab_list_lock, flags);
180                 return rc;
181         }
182
183         ref = head = gnttab_free_head;
184         gnttab_free_count -= count;
185         while (count-- > 1)
186                 head = gnttab_entry(head);
187         gnttab_free_head = gnttab_entry(head);
188         gnttab_entry(head) = GNTTAB_LIST_END;
189
190         spin_unlock_irqrestore(&gnttab_list_lock, flags);
191
192         return ref;
193 }
194
195 static void do_free_callbacks(void)
196 {
197         struct gnttab_free_callback *callback, *next;
198
199         callback = gnttab_free_callback_list;
200         gnttab_free_callback_list = NULL;
201
202         while (callback != NULL) {
203                 next = callback->next;
204                 if (gnttab_free_count >= callback->count) {
205                         callback->next = NULL;
206                         callback->fn(callback->arg);
207                 } else {
208                         callback->next = gnttab_free_callback_list;
209                         gnttab_free_callback_list = callback;
210                 }
211                 callback = next;
212         }
213 }
214
215 static inline void check_free_callbacks(void)
216 {
217         if (unlikely(gnttab_free_callback_list))
218                 do_free_callbacks();
219 }
220
221 static void put_free_entry(grant_ref_t ref)
222 {
223         unsigned long flags;
224         spin_lock_irqsave(&gnttab_list_lock, flags);
225         gnttab_entry(ref) = gnttab_free_head;
226         gnttab_free_head = ref;
227         gnttab_free_count++;
228         check_free_callbacks();
229         spin_unlock_irqrestore(&gnttab_list_lock, flags);
230 }
231
232 /*
233  * Following applies to gnttab_update_entry_v1 and gnttab_update_entry_v2.
234  * Introducing a valid entry into the grant table:
235  *  1. Write ent->domid.
236  *  2. Write ent->frame:
237  *      GTF_permit_access:   Frame to which access is permitted.
238  *      GTF_accept_transfer: Pseudo-phys frame slot being filled by new
239  *                           frame, or zero if none.
240  *  3. Write memory barrier (WMB).
241  *  4. Write ent->flags, inc. valid type.
242  */
243 static void gnttab_update_entry_v1(grant_ref_t ref, domid_t domid,
244                                    unsigned long frame, unsigned flags)
245 {
246         gnttab_shared.v1[ref].domid = domid;
247         gnttab_shared.v1[ref].frame = frame;
248         wmb();
249         gnttab_shared.v1[ref].flags = flags;
250 }
251
252 static void gnttab_update_entry_v2(grant_ref_t ref, domid_t domid,
253                                    unsigned long frame, unsigned int flags)
254 {
255         gnttab_shared.v2[ref].hdr.domid = domid;
256         gnttab_shared.v2[ref].full_page.frame = frame;
257         wmb();  /* Hypervisor concurrent accesses. */
258         gnttab_shared.v2[ref].hdr.flags = GTF_permit_access | flags;
259 }
260
261 /*
262  * Public grant-issuing interface functions
263  */
264 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
265                                      unsigned long frame, int readonly)
266 {
267         gnttab_interface->update_entry(ref, domid, frame,
268                            GTF_permit_access | (readonly ? GTF_readonly : 0));
269 }
270 EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access_ref);
271
272 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
273                                 int readonly)
274 {
275         int ref;
276
277         ref = get_free_entries(1);
278         if (unlikely(ref < 0))
279                 return -ENOSPC;
280
281         gnttab_grant_foreign_access_ref(ref, domid, frame, readonly);
282
283         return ref;
284 }
285 EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access);
286
287 static int gnttab_query_foreign_access_v1(grant_ref_t ref)
288 {
289         return gnttab_shared.v1[ref].flags & (GTF_reading|GTF_writing);
290 }
291
292 static int gnttab_query_foreign_access_v2(grant_ref_t ref)
293 {
294         return grstatus[ref] & (GTF_reading|GTF_writing);
295 }
296
297 int gnttab_query_foreign_access(grant_ref_t ref)
298 {
299         return gnttab_interface->query_foreign_access(ref);
300 }
301 EXPORT_SYMBOL_GPL(gnttab_query_foreign_access);
302
303 static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly)
304 {
305         u16 flags, nflags;
306         u16 *pflags;
307
308         pflags = &gnttab_shared.v1[ref].flags;
309         nflags = *pflags;
310         do {
311                 flags = nflags;
312                 if (flags & (GTF_reading|GTF_writing))
313                         return 0;
314         } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags);
315
316         return 1;
317 }
318
319 static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly)
320 {
321         gnttab_shared.v2[ref].hdr.flags = 0;
322         mb();   /* Concurrent access by hypervisor. */
323         if (grstatus[ref] & (GTF_reading|GTF_writing)) {
324                 return 0;
325         } else {
326                 /*
327                  * The read of grstatus needs to have acquire semantics.
328                  *  On x86, reads already have that, and we just need to
329                  * protect against compiler reorderings.
330                  * On other architectures we may need a full barrier.
331                  */
332 #ifdef CONFIG_X86
333                 barrier();
334 #else
335                 mb();
336 #endif
337         }
338
339         return 1;
340 }
341
342 static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
343 {
344         return gnttab_interface->end_foreign_access_ref(ref, readonly);
345 }
346
347 int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
348 {
349         if (_gnttab_end_foreign_access_ref(ref, readonly))
350                 return 1;
351         pr_warn("WARNING: g.e. %#x still in use!\n", ref);
352         return 0;
353 }
354 EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref);
355
356 struct deferred_entry {
357         struct list_head list;
358         grant_ref_t ref;
359         bool ro;
360         uint16_t warn_delay;
361         struct page *page;
362 };
363 static LIST_HEAD(deferred_list);
364 static void gnttab_handle_deferred(struct timer_list *);
365 static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred);
366
367 static void gnttab_handle_deferred(struct timer_list *unused)
368 {
369         unsigned int nr = 10;
370         struct deferred_entry *first = NULL;
371         unsigned long flags;
372
373         spin_lock_irqsave(&gnttab_list_lock, flags);
374         while (nr--) {
375                 struct deferred_entry *entry
376                         = list_first_entry(&deferred_list,
377                                            struct deferred_entry, list);
378
379                 if (entry == first)
380                         break;
381                 list_del(&entry->list);
382                 spin_unlock_irqrestore(&gnttab_list_lock, flags);
383                 if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) {
384                         put_free_entry(entry->ref);
385                         if (entry->page) {
386                                 pr_debug("freeing g.e. %#x (pfn %#lx)\n",
387                                          entry->ref, page_to_pfn(entry->page));
388                                 put_page(entry->page);
389                         } else
390                                 pr_info("freeing g.e. %#x\n", entry->ref);
391                         kfree(entry);
392                         entry = NULL;
393                 } else {
394                         if (!--entry->warn_delay)
395                                 pr_info("g.e. %#x still pending\n", entry->ref);
396                         if (!first)
397                                 first = entry;
398                 }
399                 spin_lock_irqsave(&gnttab_list_lock, flags);
400                 if (entry)
401                         list_add_tail(&entry->list, &deferred_list);
402                 else if (list_empty(&deferred_list))
403                         break;
404         }
405         if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) {
406                 deferred_timer.expires = jiffies + HZ;
407                 add_timer(&deferred_timer);
408         }
409         spin_unlock_irqrestore(&gnttab_list_lock, flags);
410 }
411
412 static void gnttab_add_deferred(grant_ref_t ref, bool readonly,
413                                 struct page *page)
414 {
415         struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
416         const char *what = KERN_WARNING "leaking";
417
418         if (entry) {
419                 unsigned long flags;
420
421                 entry->ref = ref;
422                 entry->ro = readonly;
423                 entry->page = page;
424                 entry->warn_delay = 60;
425                 spin_lock_irqsave(&gnttab_list_lock, flags);
426                 list_add_tail(&entry->list, &deferred_list);
427                 if (!timer_pending(&deferred_timer)) {
428                         deferred_timer.expires = jiffies + HZ;
429                         add_timer(&deferred_timer);
430                 }
431                 spin_unlock_irqrestore(&gnttab_list_lock, flags);
432                 what = KERN_DEBUG "deferring";
433         }
434         printk("%s g.e. %#x (pfn %#lx)\n",
435                what, ref, page ? page_to_pfn(page) : -1);
436 }
437
438 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
439                                unsigned long page)
440 {
441         if (gnttab_end_foreign_access_ref(ref, readonly)) {
442                 put_free_entry(ref);
443                 if (page != 0)
444                         put_page(virt_to_page(page));
445         } else
446                 gnttab_add_deferred(ref, readonly,
447                                     page ? virt_to_page(page) : NULL);
448 }
449 EXPORT_SYMBOL_GPL(gnttab_end_foreign_access);
450
451 int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn)
452 {
453         int ref;
454
455         ref = get_free_entries(1);
456         if (unlikely(ref < 0))
457                 return -ENOSPC;
458         gnttab_grant_foreign_transfer_ref(ref, domid, pfn);
459
460         return ref;
461 }
462 EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer);
463
464 void gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid,
465                                        unsigned long pfn)
466 {
467         gnttab_interface->update_entry(ref, domid, pfn, GTF_accept_transfer);
468 }
469 EXPORT_SYMBOL_GPL(gnttab_grant_foreign_transfer_ref);
470
471 static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref)
472 {
473         unsigned long frame;
474         u16           flags;
475         u16          *pflags;
476
477         pflags = &gnttab_shared.v1[ref].flags;
478
479         /*
480          * If a transfer is not even yet started, try to reclaim the grant
481          * reference and return failure (== 0).
482          */
483         while (!((flags = *pflags) & GTF_transfer_committed)) {
484                 if (sync_cmpxchg(pflags, flags, 0) == flags)
485                         return 0;
486                 cpu_relax();
487         }
488
489         /* If a transfer is in progress then wait until it is completed. */
490         while (!(flags & GTF_transfer_completed)) {
491                 flags = *pflags;
492                 cpu_relax();
493         }
494
495         rmb();  /* Read the frame number /after/ reading completion status. */
496         frame = gnttab_shared.v1[ref].frame;
497         BUG_ON(frame == 0);
498
499         return frame;
500 }
501
502 static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref)
503 {
504         unsigned long frame;
505         u16           flags;
506         u16          *pflags;
507
508         pflags = &gnttab_shared.v2[ref].hdr.flags;
509
510         /*
511          * If a transfer is not even yet started, try to reclaim the grant
512          * reference and return failure (== 0).
513          */
514         while (!((flags = *pflags) & GTF_transfer_committed)) {
515                 if (sync_cmpxchg(pflags, flags, 0) == flags)
516                         return 0;
517                 cpu_relax();
518         }
519
520         /* If a transfer is in progress then wait until it is completed. */
521         while (!(flags & GTF_transfer_completed)) {
522                 flags = *pflags;
523                 cpu_relax();
524         }
525
526         rmb();  /* Read the frame number /after/ reading completion status. */
527         frame = gnttab_shared.v2[ref].full_page.frame;
528         BUG_ON(frame == 0);
529
530         return frame;
531 }
532
533 unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref)
534 {
535         return gnttab_interface->end_foreign_transfer_ref(ref);
536 }
537 EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer_ref);
538
539 unsigned long gnttab_end_foreign_transfer(grant_ref_t ref)
540 {
541         unsigned long frame = gnttab_end_foreign_transfer_ref(ref);
542         put_free_entry(ref);
543         return frame;
544 }
545 EXPORT_SYMBOL_GPL(gnttab_end_foreign_transfer);
546
547 void gnttab_free_grant_reference(grant_ref_t ref)
548 {
549         put_free_entry(ref);
550 }
551 EXPORT_SYMBOL_GPL(gnttab_free_grant_reference);
552
553 void gnttab_free_grant_references(grant_ref_t head)
554 {
555         grant_ref_t ref;
556         unsigned long flags;
557         int count = 1;
558         if (head == GNTTAB_LIST_END)
559                 return;
560         spin_lock_irqsave(&gnttab_list_lock, flags);
561         ref = head;
562         while (gnttab_entry(ref) != GNTTAB_LIST_END) {
563                 ref = gnttab_entry(ref);
564                 count++;
565         }
566         gnttab_entry(ref) = gnttab_free_head;
567         gnttab_free_head = head;
568         gnttab_free_count += count;
569         check_free_callbacks();
570         spin_unlock_irqrestore(&gnttab_list_lock, flags);
571 }
572 EXPORT_SYMBOL_GPL(gnttab_free_grant_references);
573
574 int gnttab_alloc_grant_references(u16 count, grant_ref_t *head)
575 {
576         int h = get_free_entries(count);
577
578         if (h < 0)
579                 return -ENOSPC;
580
581         *head = h;
582
583         return 0;
584 }
585 EXPORT_SYMBOL_GPL(gnttab_alloc_grant_references);
586
587 int gnttab_empty_grant_references(const grant_ref_t *private_head)
588 {
589         return (*private_head == GNTTAB_LIST_END);
590 }
591 EXPORT_SYMBOL_GPL(gnttab_empty_grant_references);
592
593 int gnttab_claim_grant_reference(grant_ref_t *private_head)
594 {
595         grant_ref_t g = *private_head;
596         if (unlikely(g == GNTTAB_LIST_END))
597                 return -ENOSPC;
598         *private_head = gnttab_entry(g);
599         return g;
600 }
601 EXPORT_SYMBOL_GPL(gnttab_claim_grant_reference);
602
603 void gnttab_release_grant_reference(grant_ref_t *private_head,
604                                     grant_ref_t release)
605 {
606         gnttab_entry(release) = *private_head;
607         *private_head = release;
608 }
609 EXPORT_SYMBOL_GPL(gnttab_release_grant_reference);
610
611 void gnttab_request_free_callback(struct gnttab_free_callback *callback,
612                                   void (*fn)(void *), void *arg, u16 count)
613 {
614         unsigned long flags;
615         struct gnttab_free_callback *cb;
616
617         spin_lock_irqsave(&gnttab_list_lock, flags);
618
619         /* Check if the callback is already on the list */
620         cb = gnttab_free_callback_list;
621         while (cb) {
622                 if (cb == callback)
623                         goto out;
624                 cb = cb->next;
625         }
626
627         callback->fn = fn;
628         callback->arg = arg;
629         callback->count = count;
630         callback->next = gnttab_free_callback_list;
631         gnttab_free_callback_list = callback;
632         check_free_callbacks();
633 out:
634         spin_unlock_irqrestore(&gnttab_list_lock, flags);
635 }
636 EXPORT_SYMBOL_GPL(gnttab_request_free_callback);
637
638 void gnttab_cancel_free_callback(struct gnttab_free_callback *callback)
639 {
640         struct gnttab_free_callback **pcb;
641         unsigned long flags;
642
643         spin_lock_irqsave(&gnttab_list_lock, flags);
644         for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) {
645                 if (*pcb == callback) {
646                         *pcb = callback->next;
647                         break;
648                 }
649         }
650         spin_unlock_irqrestore(&gnttab_list_lock, flags);
651 }
652 EXPORT_SYMBOL_GPL(gnttab_cancel_free_callback);
653
654 static unsigned int gnttab_frames(unsigned int frames, unsigned int align)
655 {
656         return (frames * gnttab_interface->grefs_per_grant_frame + align - 1) /
657                align;
658 }
659
660 static int grow_gnttab_list(unsigned int more_frames)
661 {
662         unsigned int new_nr_grant_frames, extra_entries, i;
663         unsigned int nr_glist_frames, new_nr_glist_frames;
664         unsigned int grefs_per_frame;
665
666         grefs_per_frame = gnttab_interface->grefs_per_grant_frame;
667
668         new_nr_grant_frames = nr_grant_frames + more_frames;
669         extra_entries = more_frames * grefs_per_frame;
670
671         nr_glist_frames = gnttab_frames(nr_grant_frames, RPP);
672         new_nr_glist_frames = gnttab_frames(new_nr_grant_frames, RPP);
673         for (i = nr_glist_frames; i < new_nr_glist_frames; i++) {
674                 gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC);
675                 if (!gnttab_list[i])
676                         goto grow_nomem;
677         }
678
679
680         for (i = grefs_per_frame * nr_grant_frames;
681              i < grefs_per_frame * new_nr_grant_frames - 1; i++)
682                 gnttab_entry(i) = i + 1;
683
684         gnttab_entry(i) = gnttab_free_head;
685         gnttab_free_head = grefs_per_frame * nr_grant_frames;
686         gnttab_free_count += extra_entries;
687
688         nr_grant_frames = new_nr_grant_frames;
689
690         check_free_callbacks();
691
692         return 0;
693
694 grow_nomem:
695         while (i-- > nr_glist_frames)
696                 free_page((unsigned long) gnttab_list[i]);
697         return -ENOMEM;
698 }
699
700 static unsigned int __max_nr_grant_frames(void)
701 {
702         struct gnttab_query_size query;
703         int rc;
704
705         query.dom = DOMID_SELF;
706
707         rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1);
708         if ((rc < 0) || (query.status != GNTST_okay))
709                 return 4; /* Legacy max supported number of frames */
710
711         return query.max_nr_frames;
712 }
713
714 unsigned int gnttab_max_grant_frames(void)
715 {
716         unsigned int xen_max = __max_nr_grant_frames();
717         static unsigned int boot_max_nr_grant_frames;
718
719         /* First time, initialize it properly. */
720         if (!boot_max_nr_grant_frames)
721                 boot_max_nr_grant_frames = __max_nr_grant_frames();
722
723         if (xen_max > boot_max_nr_grant_frames)
724                 return boot_max_nr_grant_frames;
725         return xen_max;
726 }
727 EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
728
729 int gnttab_setup_auto_xlat_frames(phys_addr_t addr)
730 {
731         xen_pfn_t *pfn;
732         unsigned int max_nr_gframes = __max_nr_grant_frames();
733         unsigned int i;
734         void *vaddr;
735
736         if (xen_auto_xlat_grant_frames.count)
737                 return -EINVAL;
738
739         vaddr = xen_remap(addr, XEN_PAGE_SIZE * max_nr_gframes);
740         if (vaddr == NULL) {
741                 pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n",
742                         &addr);
743                 return -ENOMEM;
744         }
745         pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL);
746         if (!pfn) {
747                 xen_unmap(vaddr);
748                 return -ENOMEM;
749         }
750         for (i = 0; i < max_nr_gframes; i++)
751                 pfn[i] = XEN_PFN_DOWN(addr) + i;
752
753         xen_auto_xlat_grant_frames.vaddr = vaddr;
754         xen_auto_xlat_grant_frames.pfn = pfn;
755         xen_auto_xlat_grant_frames.count = max_nr_gframes;
756
757         return 0;
758 }
759 EXPORT_SYMBOL_GPL(gnttab_setup_auto_xlat_frames);
760
761 void gnttab_free_auto_xlat_frames(void)
762 {
763         if (!xen_auto_xlat_grant_frames.count)
764                 return;
765         kfree(xen_auto_xlat_grant_frames.pfn);
766         xen_unmap(xen_auto_xlat_grant_frames.vaddr);
767
768         xen_auto_xlat_grant_frames.pfn = NULL;
769         xen_auto_xlat_grant_frames.count = 0;
770         xen_auto_xlat_grant_frames.vaddr = NULL;
771 }
772 EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames);
773
774 int gnttab_pages_set_private(int nr_pages, struct page **pages)
775 {
776         int i;
777
778         for (i = 0; i < nr_pages; i++) {
779 #if BITS_PER_LONG < 64
780                 struct xen_page_foreign *foreign;
781
782                 foreign = kzalloc(sizeof(*foreign), GFP_KERNEL);
783                 if (!foreign)
784                         return -ENOMEM;
785
786                 set_page_private(pages[i], (unsigned long)foreign);
787 #endif
788                 SetPagePrivate(pages[i]);
789         }
790
791         return 0;
792 }
793 EXPORT_SYMBOL_GPL(gnttab_pages_set_private);
794
795 /**
796  * gnttab_alloc_pages - alloc pages suitable for grant mapping into
797  * @nr_pages: number of pages to alloc
798  * @pages: returns the pages
799  */
800 int gnttab_alloc_pages(int nr_pages, struct page **pages)
801 {
802         int ret;
803
804         ret = xen_alloc_unpopulated_pages(nr_pages, pages);
805         if (ret < 0)
806                 return ret;
807
808         ret = gnttab_pages_set_private(nr_pages, pages);
809         if (ret < 0)
810                 gnttab_free_pages(nr_pages, pages);
811
812         return ret;
813 }
814 EXPORT_SYMBOL_GPL(gnttab_alloc_pages);
815
816 #ifdef CONFIG_XEN_UNPOPULATED_ALLOC
817 static inline void cache_init(struct gnttab_page_cache *cache)
818 {
819         cache->pages = NULL;
820 }
821
822 static inline bool cache_empty(struct gnttab_page_cache *cache)
823 {
824         return !cache->pages;
825 }
826
827 static inline struct page *cache_deq(struct gnttab_page_cache *cache)
828 {
829         struct page *page;
830
831         page = cache->pages;
832         cache->pages = page->zone_device_data;
833
834         return page;
835 }
836
837 static inline void cache_enq(struct gnttab_page_cache *cache, struct page *page)
838 {
839         page->zone_device_data = cache->pages;
840         cache->pages = page;
841 }
842 #else
843 static inline void cache_init(struct gnttab_page_cache *cache)
844 {
845         INIT_LIST_HEAD(&cache->pages);
846 }
847
848 static inline bool cache_empty(struct gnttab_page_cache *cache)
849 {
850         return list_empty(&cache->pages);
851 }
852
853 static inline struct page *cache_deq(struct gnttab_page_cache *cache)
854 {
855         struct page *page;
856
857         page = list_first_entry(&cache->pages, struct page, lru);
858         list_del(&page->lru);
859
860         return page;
861 }
862
863 static inline void cache_enq(struct gnttab_page_cache *cache, struct page *page)
864 {
865         list_add(&page->lru, &cache->pages);
866 }
867 #endif
868
869 void gnttab_page_cache_init(struct gnttab_page_cache *cache)
870 {
871         spin_lock_init(&cache->lock);
872         cache_init(cache);
873         cache->num_pages = 0;
874 }
875 EXPORT_SYMBOL_GPL(gnttab_page_cache_init);
876
877 int gnttab_page_cache_get(struct gnttab_page_cache *cache, struct page **page)
878 {
879         unsigned long flags;
880
881         spin_lock_irqsave(&cache->lock, flags);
882
883         if (cache_empty(cache)) {
884                 spin_unlock_irqrestore(&cache->lock, flags);
885                 return gnttab_alloc_pages(1, page);
886         }
887
888         page[0] = cache_deq(cache);
889         cache->num_pages--;
890
891         spin_unlock_irqrestore(&cache->lock, flags);
892
893         return 0;
894 }
895 EXPORT_SYMBOL_GPL(gnttab_page_cache_get);
896
897 void gnttab_page_cache_put(struct gnttab_page_cache *cache, struct page **page,
898                            unsigned int num)
899 {
900         unsigned long flags;
901         unsigned int i;
902
903         spin_lock_irqsave(&cache->lock, flags);
904
905         for (i = 0; i < num; i++)
906                 cache_enq(cache, page[i]);
907         cache->num_pages += num;
908
909         spin_unlock_irqrestore(&cache->lock, flags);
910 }
911 EXPORT_SYMBOL_GPL(gnttab_page_cache_put);
912
913 void gnttab_page_cache_shrink(struct gnttab_page_cache *cache, unsigned int num)
914 {
915         struct page *page[10];
916         unsigned int i = 0;
917         unsigned long flags;
918
919         spin_lock_irqsave(&cache->lock, flags);
920
921         while (cache->num_pages > num) {
922                 page[i] = cache_deq(cache);
923                 cache->num_pages--;
924                 if (++i == ARRAY_SIZE(page)) {
925                         spin_unlock_irqrestore(&cache->lock, flags);
926                         gnttab_free_pages(i, page);
927                         i = 0;
928                         spin_lock_irqsave(&cache->lock, flags);
929                 }
930         }
931
932         spin_unlock_irqrestore(&cache->lock, flags);
933
934         if (i != 0)
935                 gnttab_free_pages(i, page);
936 }
937 EXPORT_SYMBOL_GPL(gnttab_page_cache_shrink);
938
939 void gnttab_pages_clear_private(int nr_pages, struct page **pages)
940 {
941         int i;
942
943         for (i = 0; i < nr_pages; i++) {
944                 if (PagePrivate(pages[i])) {
945 #if BITS_PER_LONG < 64
946                         kfree((void *)page_private(pages[i]));
947 #endif
948                         ClearPagePrivate(pages[i]);
949                 }
950         }
951 }
952 EXPORT_SYMBOL_GPL(gnttab_pages_clear_private);
953
954 /**
955  * gnttab_free_pages - free pages allocated by gnttab_alloc_pages()
956  * @nr_pages; number of pages to free
957  * @pages: the pages
958  */
959 void gnttab_free_pages(int nr_pages, struct page **pages)
960 {
961         gnttab_pages_clear_private(nr_pages, pages);
962         xen_free_unpopulated_pages(nr_pages, pages);
963 }
964 EXPORT_SYMBOL_GPL(gnttab_free_pages);
965
966 #ifdef CONFIG_XEN_GRANT_DMA_ALLOC
967 /**
968  * gnttab_dma_alloc_pages - alloc DMAable pages suitable for grant mapping into
969  * @args: arguments to the function
970  */
971 int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args)
972 {
973         unsigned long pfn, start_pfn;
974         size_t size;
975         int i, ret;
976
977         size = args->nr_pages << PAGE_SHIFT;
978         if (args->coherent)
979                 args->vaddr = dma_alloc_coherent(args->dev, size,
980                                                  &args->dev_bus_addr,
981                                                  GFP_KERNEL | __GFP_NOWARN);
982         else
983                 args->vaddr = dma_alloc_wc(args->dev, size,
984                                            &args->dev_bus_addr,
985                                            GFP_KERNEL | __GFP_NOWARN);
986         if (!args->vaddr) {
987                 pr_debug("Failed to allocate DMA buffer of size %zu\n", size);
988                 return -ENOMEM;
989         }
990
991         start_pfn = __phys_to_pfn(args->dev_bus_addr);
992         for (pfn = start_pfn, i = 0; pfn < start_pfn + args->nr_pages;
993                         pfn++, i++) {
994                 struct page *page = pfn_to_page(pfn);
995
996                 args->pages[i] = page;
997                 args->frames[i] = xen_page_to_gfn(page);
998                 xenmem_reservation_scrub_page(page);
999         }
1000
1001         xenmem_reservation_va_mapping_reset(args->nr_pages, args->pages);
1002
1003         ret = xenmem_reservation_decrease(args->nr_pages, args->frames);
1004         if (ret != args->nr_pages) {
1005                 pr_debug("Failed to decrease reservation for DMA buffer\n");
1006                 ret = -EFAULT;
1007                 goto fail;
1008         }
1009
1010         ret = gnttab_pages_set_private(args->nr_pages, args->pages);
1011         if (ret < 0)
1012                 goto fail;
1013
1014         return 0;
1015
1016 fail:
1017         gnttab_dma_free_pages(args);
1018         return ret;
1019 }
1020 EXPORT_SYMBOL_GPL(gnttab_dma_alloc_pages);
1021
1022 /**
1023  * gnttab_dma_free_pages - free DMAable pages
1024  * @args: arguments to the function
1025  */
1026 int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args)
1027 {
1028         size_t size;
1029         int i, ret;
1030
1031         gnttab_pages_clear_private(args->nr_pages, args->pages);
1032
1033         for (i = 0; i < args->nr_pages; i++)
1034                 args->frames[i] = page_to_xen_pfn(args->pages[i]);
1035
1036         ret = xenmem_reservation_increase(args->nr_pages, args->frames);
1037         if (ret != args->nr_pages) {
1038                 pr_debug("Failed to increase reservation for DMA buffer\n");
1039                 ret = -EFAULT;
1040         } else {
1041                 ret = 0;
1042         }
1043
1044         xenmem_reservation_va_mapping_update(args->nr_pages, args->pages,
1045                                              args->frames);
1046
1047         size = args->nr_pages << PAGE_SHIFT;
1048         if (args->coherent)
1049                 dma_free_coherent(args->dev, size,
1050                                   args->vaddr, args->dev_bus_addr);
1051         else
1052                 dma_free_wc(args->dev, size,
1053                             args->vaddr, args->dev_bus_addr);
1054         return ret;
1055 }
1056 EXPORT_SYMBOL_GPL(gnttab_dma_free_pages);
1057 #endif
1058
1059 /* Handling of paged out grant targets (GNTST_eagain) */
1060 #define MAX_DELAY 256
1061 static inline void
1062 gnttab_retry_eagain_gop(unsigned int cmd, void *gop, int16_t *status,
1063                                                 const char *func)
1064 {
1065         unsigned delay = 1;
1066
1067         do {
1068                 BUG_ON(HYPERVISOR_grant_table_op(cmd, gop, 1));
1069                 if (*status == GNTST_eagain)
1070                         msleep(delay++);
1071         } while ((*status == GNTST_eagain) && (delay < MAX_DELAY));
1072
1073         if (delay >= MAX_DELAY) {
1074                 pr_err("%s: %s eagain grant\n", func, current->comm);
1075                 *status = GNTST_bad_page;
1076         }
1077 }
1078
1079 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count)
1080 {
1081         struct gnttab_map_grant_ref *op;
1082
1083         if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, batch, count))
1084                 BUG();
1085         for (op = batch; op < batch + count; op++)
1086                 if (op->status == GNTST_eagain)
1087                         gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, op,
1088                                                 &op->status, __func__);
1089 }
1090 EXPORT_SYMBOL_GPL(gnttab_batch_map);
1091
1092 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count)
1093 {
1094         struct gnttab_copy *op;
1095
1096         if (HYPERVISOR_grant_table_op(GNTTABOP_copy, batch, count))
1097                 BUG();
1098         for (op = batch; op < batch + count; op++)
1099                 if (op->status == GNTST_eagain)
1100                         gnttab_retry_eagain_gop(GNTTABOP_copy, op,
1101                                                 &op->status, __func__);
1102 }
1103 EXPORT_SYMBOL_GPL(gnttab_batch_copy);
1104
1105 void gnttab_foreach_grant_in_range(struct page *page,
1106                                    unsigned int offset,
1107                                    unsigned int len,
1108                                    xen_grant_fn_t fn,
1109                                    void *data)
1110 {
1111         unsigned int goffset;
1112         unsigned int glen;
1113         unsigned long xen_pfn;
1114
1115         len = min_t(unsigned int, PAGE_SIZE - offset, len);
1116         goffset = xen_offset_in_page(offset);
1117
1118         xen_pfn = page_to_xen_pfn(page) + XEN_PFN_DOWN(offset);
1119
1120         while (len) {
1121                 glen = min_t(unsigned int, XEN_PAGE_SIZE - goffset, len);
1122                 fn(pfn_to_gfn(xen_pfn), goffset, glen, data);
1123
1124                 goffset = 0;
1125                 xen_pfn++;
1126                 len -= glen;
1127         }
1128 }
1129 EXPORT_SYMBOL_GPL(gnttab_foreach_grant_in_range);
1130
1131 void gnttab_foreach_grant(struct page **pages,
1132                           unsigned int nr_grefs,
1133                           xen_grant_fn_t fn,
1134                           void *data)
1135 {
1136         unsigned int goffset = 0;
1137         unsigned long xen_pfn = 0;
1138         unsigned int i;
1139
1140         for (i = 0; i < nr_grefs; i++) {
1141                 if ((i % XEN_PFN_PER_PAGE) == 0) {
1142                         xen_pfn = page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]);
1143                         goffset = 0;
1144                 }
1145
1146                 fn(pfn_to_gfn(xen_pfn), goffset, XEN_PAGE_SIZE, data);
1147
1148                 goffset += XEN_PAGE_SIZE;
1149                 xen_pfn++;
1150         }
1151 }
1152
1153 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
1154                     struct gnttab_map_grant_ref *kmap_ops,
1155                     struct page **pages, unsigned int count)
1156 {
1157         int i, ret;
1158
1159         ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count);
1160         if (ret)
1161                 return ret;
1162
1163         for (i = 0; i < count; i++) {
1164                 switch (map_ops[i].status) {
1165                 case GNTST_okay:
1166                 {
1167                         struct xen_page_foreign *foreign;
1168
1169                         SetPageForeign(pages[i]);
1170                         foreign = xen_page_foreign(pages[i]);
1171                         foreign->domid = map_ops[i].dom;
1172                         foreign->gref = map_ops[i].ref;
1173                         break;
1174                 }
1175
1176                 case GNTST_no_device_space:
1177                         pr_warn_ratelimited("maptrack limit reached, can't map all guest pages\n");
1178                         break;
1179
1180                 case GNTST_eagain:
1181                         /* Retry eagain maps */
1182                         gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref,
1183                                                 map_ops + i,
1184                                                 &map_ops[i].status, __func__);
1185                         /* Test status in next loop iteration. */
1186                         i--;
1187                         break;
1188
1189                 default:
1190                         break;
1191                 }
1192         }
1193
1194         return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count);
1195 }
1196 EXPORT_SYMBOL_GPL(gnttab_map_refs);
1197
1198 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
1199                       struct gnttab_unmap_grant_ref *kunmap_ops,
1200                       struct page **pages, unsigned int count)
1201 {
1202         unsigned int i;
1203         int ret;
1204
1205         ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
1206         if (ret)
1207                 return ret;
1208
1209         for (i = 0; i < count; i++)
1210                 ClearPageForeign(pages[i]);
1211
1212         return clear_foreign_p2m_mapping(unmap_ops, kunmap_ops, pages, count);
1213 }
1214 EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
1215
1216 #define GNTTAB_UNMAP_REFS_DELAY 5
1217
1218 static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
1219
1220 static void gnttab_unmap_work(struct work_struct *work)
1221 {
1222         struct gntab_unmap_queue_data
1223                 *unmap_data = container_of(work, 
1224                                            struct gntab_unmap_queue_data,
1225                                            gnttab_work.work);
1226         if (unmap_data->age != UINT_MAX)
1227                 unmap_data->age++;
1228         __gnttab_unmap_refs_async(unmap_data);
1229 }
1230
1231 static void __gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item)
1232 {
1233         int ret;
1234         int pc;
1235
1236         for (pc = 0; pc < item->count; pc++) {
1237                 if (page_count(item->pages[pc]) > 1) {
1238                         unsigned long delay = GNTTAB_UNMAP_REFS_DELAY * (item->age + 1);
1239                         schedule_delayed_work(&item->gnttab_work,
1240                                               msecs_to_jiffies(delay));
1241                         return;
1242                 }
1243         }
1244
1245         ret = gnttab_unmap_refs(item->unmap_ops, item->kunmap_ops,
1246                                 item->pages, item->count);
1247         item->done(ret, item);
1248 }
1249
1250 void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item)
1251 {
1252         INIT_DELAYED_WORK(&item->gnttab_work, gnttab_unmap_work);
1253         item->age = 0;
1254
1255         __gnttab_unmap_refs_async(item);
1256 }
1257 EXPORT_SYMBOL_GPL(gnttab_unmap_refs_async);
1258
1259 static void unmap_refs_callback(int result,
1260                 struct gntab_unmap_queue_data *data)
1261 {
1262         struct unmap_refs_callback_data *d = data->data;
1263
1264         d->result = result;
1265         complete(&d->completion);
1266 }
1267
1268 int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item)
1269 {
1270         struct unmap_refs_callback_data data;
1271
1272         init_completion(&data.completion);
1273         item->data = &data;
1274         item->done = &unmap_refs_callback;
1275         gnttab_unmap_refs_async(item);
1276         wait_for_completion(&data.completion);
1277
1278         return data.result;
1279 }
1280 EXPORT_SYMBOL_GPL(gnttab_unmap_refs_sync);
1281
1282 static unsigned int nr_status_frames(unsigned int nr_grant_frames)
1283 {
1284         return gnttab_frames(nr_grant_frames, SPP);
1285 }
1286
1287 static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes)
1288 {
1289         int rc;
1290
1291         rc = arch_gnttab_map_shared(frames, nr_gframes,
1292                                     gnttab_max_grant_frames(),
1293                                     &gnttab_shared.addr);
1294         BUG_ON(rc);
1295
1296         return 0;
1297 }
1298
1299 static void gnttab_unmap_frames_v1(void)
1300 {
1301         arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames);
1302 }
1303
1304 static int gnttab_map_frames_v2(xen_pfn_t *frames, unsigned int nr_gframes)
1305 {
1306         uint64_t *sframes;
1307         unsigned int nr_sframes;
1308         struct gnttab_get_status_frames getframes;
1309         int rc;
1310
1311         nr_sframes = nr_status_frames(nr_gframes);
1312
1313         /* No need for kzalloc as it is initialized in following hypercall
1314          * GNTTABOP_get_status_frames.
1315          */
1316         sframes = kmalloc_array(nr_sframes, sizeof(uint64_t), GFP_ATOMIC);
1317         if (!sframes)
1318                 return -ENOMEM;
1319
1320         getframes.dom        = DOMID_SELF;
1321         getframes.nr_frames  = nr_sframes;
1322         set_xen_guest_handle(getframes.frame_list, sframes);
1323
1324         rc = HYPERVISOR_grant_table_op(GNTTABOP_get_status_frames,
1325                                        &getframes, 1);
1326         if (rc == -ENOSYS) {
1327                 kfree(sframes);
1328                 return -ENOSYS;
1329         }
1330
1331         BUG_ON(rc || getframes.status);
1332
1333         rc = arch_gnttab_map_status(sframes, nr_sframes,
1334                                     nr_status_frames(gnttab_max_grant_frames()),
1335                                     &grstatus);
1336         BUG_ON(rc);
1337         kfree(sframes);
1338
1339         rc = arch_gnttab_map_shared(frames, nr_gframes,
1340                                     gnttab_max_grant_frames(),
1341                                     &gnttab_shared.addr);
1342         BUG_ON(rc);
1343
1344         return 0;
1345 }
1346
1347 static void gnttab_unmap_frames_v2(void)
1348 {
1349         arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames);
1350         arch_gnttab_unmap(grstatus, nr_status_frames(nr_grant_frames));
1351 }
1352
1353 static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
1354 {
1355         struct gnttab_setup_table setup;
1356         xen_pfn_t *frames;
1357         unsigned int nr_gframes = end_idx + 1;
1358         int rc;
1359
1360         if (xen_feature(XENFEAT_auto_translated_physmap)) {
1361                 struct xen_add_to_physmap xatp;
1362                 unsigned int i = end_idx;
1363                 rc = 0;
1364                 BUG_ON(xen_auto_xlat_grant_frames.count < nr_gframes);
1365                 /*
1366                  * Loop backwards, so that the first hypercall has the largest
1367                  * index, ensuring that the table will grow only once.
1368                  */
1369                 do {
1370                         xatp.domid = DOMID_SELF;
1371                         xatp.idx = i;
1372                         xatp.space = XENMAPSPACE_grant_table;
1373                         xatp.gpfn = xen_auto_xlat_grant_frames.pfn[i];
1374                         rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
1375                         if (rc != 0) {
1376                                 pr_warn("grant table add_to_physmap failed, err=%d\n",
1377                                         rc);
1378                                 break;
1379                         }
1380                 } while (i-- > start_idx);
1381
1382                 return rc;
1383         }
1384
1385         /* No need for kzalloc as it is initialized in following hypercall
1386          * GNTTABOP_setup_table.
1387          */
1388         frames = kmalloc_array(nr_gframes, sizeof(unsigned long), GFP_ATOMIC);
1389         if (!frames)
1390                 return -ENOMEM;
1391
1392         setup.dom        = DOMID_SELF;
1393         setup.nr_frames  = nr_gframes;
1394         set_xen_guest_handle(setup.frame_list, frames);
1395
1396         rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1);
1397         if (rc == -ENOSYS) {
1398                 kfree(frames);
1399                 return -ENOSYS;
1400         }
1401
1402         BUG_ON(rc || setup.status);
1403
1404         rc = gnttab_interface->map_frames(frames, nr_gframes);
1405
1406         kfree(frames);
1407
1408         return rc;
1409 }
1410
1411 static const struct gnttab_ops gnttab_v1_ops = {
1412         .version                        = 1,
1413         .grefs_per_grant_frame          = XEN_PAGE_SIZE /
1414                                           sizeof(struct grant_entry_v1),
1415         .map_frames                     = gnttab_map_frames_v1,
1416         .unmap_frames                   = gnttab_unmap_frames_v1,
1417         .update_entry                   = gnttab_update_entry_v1,
1418         .end_foreign_access_ref         = gnttab_end_foreign_access_ref_v1,
1419         .end_foreign_transfer_ref       = gnttab_end_foreign_transfer_ref_v1,
1420         .query_foreign_access           = gnttab_query_foreign_access_v1,
1421 };
1422
1423 static const struct gnttab_ops gnttab_v2_ops = {
1424         .version                        = 2,
1425         .grefs_per_grant_frame          = XEN_PAGE_SIZE /
1426                                           sizeof(union grant_entry_v2),
1427         .map_frames                     = gnttab_map_frames_v2,
1428         .unmap_frames                   = gnttab_unmap_frames_v2,
1429         .update_entry                   = gnttab_update_entry_v2,
1430         .end_foreign_access_ref         = gnttab_end_foreign_access_ref_v2,
1431         .end_foreign_transfer_ref       = gnttab_end_foreign_transfer_ref_v2,
1432         .query_foreign_access           = gnttab_query_foreign_access_v2,
1433 };
1434
1435 static bool gnttab_need_v2(void)
1436 {
1437 #ifdef CONFIG_X86
1438         uint32_t base, width;
1439
1440         if (xen_pv_domain()) {
1441                 base = xen_cpuid_base();
1442                 if (cpuid_eax(base) < 5)
1443                         return false;   /* Information not available, use V1. */
1444                 width = cpuid_ebx(base + 5) &
1445                         XEN_CPUID_MACHINE_ADDRESS_WIDTH_MASK;
1446                 return width > 32 + PAGE_SHIFT;
1447         }
1448 #endif
1449         return !!(max_possible_pfn >> 32);
1450 }
1451
1452 static void gnttab_request_version(void)
1453 {
1454         long rc;
1455         struct gnttab_set_version gsv;
1456
1457         if (gnttab_need_v2())
1458                 gsv.version = 2;
1459         else
1460                 gsv.version = 1;
1461
1462         /* Boot parameter overrides automatic selection. */
1463         if (xen_gnttab_version >= 1 && xen_gnttab_version <= 2)
1464                 gsv.version = xen_gnttab_version;
1465
1466         rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1);
1467         if (rc == 0 && gsv.version == 2)
1468                 gnttab_interface = &gnttab_v2_ops;
1469         else
1470                 gnttab_interface = &gnttab_v1_ops;
1471         pr_info("Grant tables using version %d layout\n",
1472                 gnttab_interface->version);
1473 }
1474
1475 static int gnttab_setup(void)
1476 {
1477         unsigned int max_nr_gframes;
1478
1479         max_nr_gframes = gnttab_max_grant_frames();
1480         if (max_nr_gframes < nr_grant_frames)
1481                 return -ENOSYS;
1482
1483         if (xen_feature(XENFEAT_auto_translated_physmap) && gnttab_shared.addr == NULL) {
1484                 gnttab_shared.addr = xen_auto_xlat_grant_frames.vaddr;
1485                 if (gnttab_shared.addr == NULL) {
1486                         pr_warn("gnttab share frames is not mapped!\n");
1487                         return -ENOMEM;
1488                 }
1489         }
1490         return gnttab_map(0, nr_grant_frames - 1);
1491 }
1492
1493 int gnttab_resume(void)
1494 {
1495         gnttab_request_version();
1496         return gnttab_setup();
1497 }
1498
1499 int gnttab_suspend(void)
1500 {
1501         if (!xen_feature(XENFEAT_auto_translated_physmap))
1502                 gnttab_interface->unmap_frames();
1503         return 0;
1504 }
1505
1506 static int gnttab_expand(unsigned int req_entries)
1507 {
1508         int rc;
1509         unsigned int cur, extra;
1510
1511         cur = nr_grant_frames;
1512         extra = ((req_entries + gnttab_interface->grefs_per_grant_frame - 1) /
1513                  gnttab_interface->grefs_per_grant_frame);
1514         if (cur + extra > gnttab_max_grant_frames()) {
1515                 pr_warn_ratelimited("xen/grant-table: max_grant_frames reached"
1516                                     " cur=%u extra=%u limit=%u"
1517                                     " gnttab_free_count=%u req_entries=%u\n",
1518                                     cur, extra, gnttab_max_grant_frames(),
1519                                     gnttab_free_count, req_entries);
1520                 return -ENOSPC;
1521         }
1522
1523         rc = gnttab_map(cur, cur + extra - 1);
1524         if (rc == 0)
1525                 rc = grow_gnttab_list(extra);
1526
1527         return rc;
1528 }
1529
1530 int gnttab_init(void)
1531 {
1532         int i;
1533         unsigned long max_nr_grant_frames;
1534         unsigned int max_nr_glist_frames, nr_glist_frames;
1535         unsigned int nr_init_grefs;
1536         int ret;
1537
1538         gnttab_request_version();
1539         max_nr_grant_frames = gnttab_max_grant_frames();
1540         nr_grant_frames = 1;
1541
1542         /* Determine the maximum number of frames required for the
1543          * grant reference free list on the current hypervisor.
1544          */
1545         max_nr_glist_frames = (max_nr_grant_frames *
1546                                gnttab_interface->grefs_per_grant_frame / RPP);
1547
1548         gnttab_list = kmalloc_array(max_nr_glist_frames,
1549                                     sizeof(grant_ref_t *),
1550                                     GFP_KERNEL);
1551         if (gnttab_list == NULL)
1552                 return -ENOMEM;
1553
1554         nr_glist_frames = gnttab_frames(nr_grant_frames, RPP);
1555         for (i = 0; i < nr_glist_frames; i++) {
1556                 gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL);
1557                 if (gnttab_list[i] == NULL) {
1558                         ret = -ENOMEM;
1559                         goto ini_nomem;
1560                 }
1561         }
1562
1563         ret = arch_gnttab_init(max_nr_grant_frames,
1564                                nr_status_frames(max_nr_grant_frames));
1565         if (ret < 0)
1566                 goto ini_nomem;
1567
1568         if (gnttab_setup() < 0) {
1569                 ret = -ENODEV;
1570                 goto ini_nomem;
1571         }
1572
1573         nr_init_grefs = nr_grant_frames *
1574                         gnttab_interface->grefs_per_grant_frame;
1575
1576         for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
1577                 gnttab_entry(i) = i + 1;
1578
1579         gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END;
1580         gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES;
1581         gnttab_free_head  = NR_RESERVED_ENTRIES;
1582
1583         printk("Grant table initialized\n");
1584         return 0;
1585
1586  ini_nomem:
1587         for (i--; i >= 0; i--)
1588                 free_page((unsigned long)gnttab_list[i]);
1589         kfree(gnttab_list);
1590         return ret;
1591 }
1592 EXPORT_SYMBOL_GPL(gnttab_init);
1593
1594 static int __gnttab_init(void)
1595 {
1596         if (!xen_domain())
1597                 return -ENODEV;
1598
1599         /* Delay grant-table initialization in the PV on HVM case */
1600         if (xen_hvm_domain() && !xen_pvh_domain())
1601                 return 0;
1602
1603         return gnttab_init();
1604 }
1605 /* Starts after core_initcall so that xen_pvh_gnttab_setup can be called
1606  * beforehand to initialize xen_auto_xlat_grant_frames. */
1607 core_initcall_sync(__gnttab_init);