2 * Copyright IBM Corp. 2007, 2011
3 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
6 #include <linux/sched.h>
7 #include <linux/kernel.h>
8 #include <linux/errno.h>
11 #include <linux/swap.h>
12 #include <linux/smp.h>
13 #include <linux/spinlock.h>
14 #include <linux/rcupdate.h>
15 #include <linux/slab.h>
16 #include <linux/swapops.h>
17 #include <linux/sysctl.h>
18 #include <linux/ksm.h>
19 #include <linux/mman.h>
21 #include <asm/pgtable.h>
22 #include <asm/pgalloc.h>
24 #include <asm/tlbflush.h>
25 #include <asm/mmu_context.h>
27 unsigned long *crst_table_alloc(struct mm_struct
*mm
)
29 struct page
*page
= alloc_pages(GFP_KERNEL
, 2);
33 return (unsigned long *) page_to_phys(page
);
36 void crst_table_free(struct mm_struct
*mm
, unsigned long *table
)
38 free_pages((unsigned long) table
, 2);
41 static void __crst_table_upgrade(void *arg
)
43 struct mm_struct
*mm
= arg
;
45 if (current
->active_mm
== mm
) {
52 int crst_table_upgrade(struct mm_struct
*mm
, unsigned long limit
)
54 unsigned long *table
, *pgd
;
58 BUG_ON(limit
> TASK_MAX_SIZE
);
61 table
= crst_table_alloc(mm
);
64 spin_lock_bh(&mm
->page_table_lock
);
65 if (mm
->context
.asce_limit
< limit
) {
66 pgd
= (unsigned long *) mm
->pgd
;
67 if (mm
->context
.asce_limit
<= (1UL << 31)) {
68 entry
= _REGION3_ENTRY_EMPTY
;
69 mm
->context
.asce_limit
= 1UL << 42;
70 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
74 entry
= _REGION2_ENTRY_EMPTY
;
75 mm
->context
.asce_limit
= 1UL << 53;
76 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
80 crst_table_init(table
, entry
);
81 pgd_populate(mm
, (pgd_t
*) table
, (pud_t
*) pgd
);
82 mm
->pgd
= (pgd_t
*) table
;
83 mm
->task_size
= mm
->context
.asce_limit
;
87 spin_unlock_bh(&mm
->page_table_lock
);
89 crst_table_free(mm
, table
);
90 if (mm
->context
.asce_limit
< limit
)
93 on_each_cpu(__crst_table_upgrade
, mm
, 0);
97 void crst_table_downgrade(struct mm_struct
*mm
, unsigned long limit
)
101 if (current
->active_mm
== mm
) {
105 while (mm
->context
.asce_limit
> limit
) {
107 switch (pgd_val(*pgd
) & _REGION_ENTRY_TYPE_MASK
) {
108 case _REGION_ENTRY_TYPE_R2
:
109 mm
->context
.asce_limit
= 1UL << 42;
110 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
114 case _REGION_ENTRY_TYPE_R3
:
115 mm
->context
.asce_limit
= 1UL << 31;
116 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
123 mm
->pgd
= (pgd_t
*) (pgd_val(*pgd
) & _REGION_ENTRY_ORIGIN
);
124 mm
->task_size
= mm
->context
.asce_limit
;
125 crst_table_free(mm
, (unsigned long *) pgd
);
127 if (current
->active_mm
== mm
)
134 * gmap_alloc - allocate a guest address space
135 * @mm: pointer to the parent mm_struct
136 * @limit: maximum address of the gmap address space
138 * Returns a guest address space structure.
140 struct gmap
*gmap_alloc(struct mm_struct
*mm
, unsigned long limit
)
144 unsigned long *table
;
145 unsigned long etype
, atype
;
147 if (limit
< (1UL << 31)) {
148 limit
= (1UL << 31) - 1;
149 atype
= _ASCE_TYPE_SEGMENT
;
150 etype
= _SEGMENT_ENTRY_EMPTY
;
151 } else if (limit
< (1UL << 42)) {
152 limit
= (1UL << 42) - 1;
153 atype
= _ASCE_TYPE_REGION3
;
154 etype
= _REGION3_ENTRY_EMPTY
;
155 } else if (limit
< (1UL << 53)) {
156 limit
= (1UL << 53) - 1;
157 atype
= _ASCE_TYPE_REGION2
;
158 etype
= _REGION2_ENTRY_EMPTY
;
161 atype
= _ASCE_TYPE_REGION1
;
162 etype
= _REGION1_ENTRY_EMPTY
;
164 gmap
= kzalloc(sizeof(struct gmap
), GFP_KERNEL
);
167 INIT_LIST_HEAD(&gmap
->crst_list
);
168 INIT_RADIX_TREE(&gmap
->guest_to_host
, GFP_KERNEL
);
169 INIT_RADIX_TREE(&gmap
->host_to_guest
, GFP_ATOMIC
);
170 spin_lock_init(&gmap
->guest_table_lock
);
172 page
= alloc_pages(GFP_KERNEL
, 2);
176 list_add(&page
->lru
, &gmap
->crst_list
);
177 table
= (unsigned long *) page_to_phys(page
);
178 crst_table_init(table
, etype
);
180 gmap
->asce
= atype
| _ASCE_TABLE_LENGTH
|
181 _ASCE_USER_BITS
| __pa(table
);
182 gmap
->asce_end
= limit
;
183 down_write(&mm
->mmap_sem
);
184 list_add(&gmap
->list
, &mm
->context
.gmap_list
);
185 up_write(&mm
->mmap_sem
);
193 EXPORT_SYMBOL_GPL(gmap_alloc
);
195 static void gmap_flush_tlb(struct gmap
*gmap
)
197 if (MACHINE_HAS_IDTE
)
198 __tlb_flush_asce(gmap
->mm
, gmap
->asce
);
200 __tlb_flush_global();
203 static void gmap_radix_tree_free(struct radix_tree_root
*root
)
205 struct radix_tree_iter iter
;
206 unsigned long indices
[16];
211 /* A radix tree is freed by deleting all of its entries */
215 radix_tree_for_each_slot(slot
, root
, &iter
, index
) {
216 indices
[nr
] = iter
.index
;
220 for (i
= 0; i
< nr
; i
++) {
222 radix_tree_delete(root
, index
);
228 * gmap_free - free a guest address space
229 * @gmap: pointer to the guest address space structure
231 void gmap_free(struct gmap
*gmap
)
233 struct page
*page
, *next
;
236 if (MACHINE_HAS_IDTE
)
237 __tlb_flush_asce(gmap
->mm
, gmap
->asce
);
239 __tlb_flush_global();
241 /* Free all segment & region tables. */
242 list_for_each_entry_safe(page
, next
, &gmap
->crst_list
, lru
)
243 __free_pages(page
, 2);
244 gmap_radix_tree_free(&gmap
->guest_to_host
);
245 gmap_radix_tree_free(&gmap
->host_to_guest
);
246 down_write(&gmap
->mm
->mmap_sem
);
247 list_del(&gmap
->list
);
248 up_write(&gmap
->mm
->mmap_sem
);
251 EXPORT_SYMBOL_GPL(gmap_free
);
254 * gmap_enable - switch primary space to the guest address space
255 * @gmap: pointer to the guest address space structure
257 void gmap_enable(struct gmap
*gmap
)
259 S390_lowcore
.gmap
= (unsigned long) gmap
;
261 EXPORT_SYMBOL_GPL(gmap_enable
);
264 * gmap_disable - switch back to the standard primary address space
265 * @gmap: pointer to the guest address space structure
267 void gmap_disable(struct gmap
*gmap
)
269 S390_lowcore
.gmap
= 0UL;
271 EXPORT_SYMBOL_GPL(gmap_disable
);
274 * gmap_alloc_table is assumed to be called with mmap_sem held
276 static int gmap_alloc_table(struct gmap
*gmap
, unsigned long *table
,
277 unsigned long init
, unsigned long gaddr
)
282 /* since we dont free the gmap table until gmap_free we can unlock */
283 page
= alloc_pages(GFP_KERNEL
, 2);
286 new = (unsigned long *) page_to_phys(page
);
287 crst_table_init(new, init
);
288 spin_lock(&gmap
->mm
->page_table_lock
);
289 if (*table
& _REGION_ENTRY_INVALID
) {
290 list_add(&page
->lru
, &gmap
->crst_list
);
291 *table
= (unsigned long) new | _REGION_ENTRY_LENGTH
|
292 (*table
& _REGION_ENTRY_TYPE_MASK
);
296 spin_unlock(&gmap
->mm
->page_table_lock
);
298 __free_pages(page
, 2);
303 * __gmap_segment_gaddr - find virtual address from segment pointer
304 * @entry: pointer to a segment table entry in the guest address space
306 * Returns the virtual address in the guest address space for the segment
308 static unsigned long __gmap_segment_gaddr(unsigned long *entry
)
311 unsigned long offset
, mask
;
313 offset
= (unsigned long) entry
/ sizeof(unsigned long);
314 offset
= (offset
& (PTRS_PER_PMD
- 1)) * PMD_SIZE
;
315 mask
= ~(PTRS_PER_PMD
* sizeof(pmd_t
) - 1);
316 page
= virt_to_page((void *)((unsigned long) entry
& mask
));
317 return page
->index
+ offset
;
321 * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
322 * @gmap: pointer to the guest address space structure
323 * @vmaddr: address in the host process address space
325 * Returns 1 if a TLB flush is required
327 static int __gmap_unlink_by_vmaddr(struct gmap
*gmap
, unsigned long vmaddr
)
329 unsigned long *entry
;
332 spin_lock(&gmap
->guest_table_lock
);
333 entry
= radix_tree_delete(&gmap
->host_to_guest
, vmaddr
>> PMD_SHIFT
);
335 flush
= (*entry
!= _SEGMENT_ENTRY_INVALID
);
336 *entry
= _SEGMENT_ENTRY_INVALID
;
338 spin_unlock(&gmap
->guest_table_lock
);
343 * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
344 * @gmap: pointer to the guest address space structure
345 * @gaddr: address in the guest address space
347 * Returns 1 if a TLB flush is required
349 static int __gmap_unmap_by_gaddr(struct gmap
*gmap
, unsigned long gaddr
)
351 unsigned long vmaddr
;
353 vmaddr
= (unsigned long) radix_tree_delete(&gmap
->guest_to_host
,
355 return vmaddr
? __gmap_unlink_by_vmaddr(gmap
, vmaddr
) : 0;
359 * gmap_unmap_segment - unmap segment from the guest address space
360 * @gmap: pointer to the guest address space structure
361 * @to: address in the guest address space
362 * @len: length of the memory area to unmap
364 * Returns 0 if the unmap succeeded, -EINVAL if not.
366 int gmap_unmap_segment(struct gmap
*gmap
, unsigned long to
, unsigned long len
)
371 if ((to
| len
) & (PMD_SIZE
- 1))
373 if (len
== 0 || to
+ len
< to
)
377 down_write(&gmap
->mm
->mmap_sem
);
378 for (off
= 0; off
< len
; off
+= PMD_SIZE
)
379 flush
|= __gmap_unmap_by_gaddr(gmap
, to
+ off
);
380 up_write(&gmap
->mm
->mmap_sem
);
382 gmap_flush_tlb(gmap
);
385 EXPORT_SYMBOL_GPL(gmap_unmap_segment
);
388 * gmap_mmap_segment - map a segment to the guest address space
389 * @gmap: pointer to the guest address space structure
390 * @from: source address in the parent address space
391 * @to: target address in the guest address space
392 * @len: length of the memory area to map
394 * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
396 int gmap_map_segment(struct gmap
*gmap
, unsigned long from
,
397 unsigned long to
, unsigned long len
)
402 if ((from
| to
| len
) & (PMD_SIZE
- 1))
404 if (len
== 0 || from
+ len
< from
|| to
+ len
< to
||
405 from
+ len
- 1 > TASK_MAX_SIZE
|| to
+ len
- 1 > gmap
->asce_end
)
409 down_write(&gmap
->mm
->mmap_sem
);
410 for (off
= 0; off
< len
; off
+= PMD_SIZE
) {
411 /* Remove old translation */
412 flush
|= __gmap_unmap_by_gaddr(gmap
, to
+ off
);
413 /* Store new translation */
414 if (radix_tree_insert(&gmap
->guest_to_host
,
415 (to
+ off
) >> PMD_SHIFT
,
416 (void *) from
+ off
))
419 up_write(&gmap
->mm
->mmap_sem
);
421 gmap_flush_tlb(gmap
);
424 gmap_unmap_segment(gmap
, to
, len
);
427 EXPORT_SYMBOL_GPL(gmap_map_segment
);
430 * __gmap_translate - translate a guest address to a user space address
431 * @gmap: pointer to guest mapping meta data structure
432 * @gaddr: guest address
434 * Returns user space address which corresponds to the guest address or
435 * -EFAULT if no such mapping exists.
436 * This function does not establish potentially missing page table entries.
437 * The mmap_sem of the mm that belongs to the address space must be held
438 * when this function gets called.
440 unsigned long __gmap_translate(struct gmap
*gmap
, unsigned long gaddr
)
442 unsigned long vmaddr
;
444 vmaddr
= (unsigned long)
445 radix_tree_lookup(&gmap
->guest_to_host
, gaddr
>> PMD_SHIFT
);
446 return vmaddr
? (vmaddr
| (gaddr
& ~PMD_MASK
)) : -EFAULT
;
448 EXPORT_SYMBOL_GPL(__gmap_translate
);
451 * gmap_translate - translate a guest address to a user space address
452 * @gmap: pointer to guest mapping meta data structure
453 * @gaddr: guest address
455 * Returns user space address which corresponds to the guest address or
456 * -EFAULT if no such mapping exists.
457 * This function does not establish potentially missing page table entries.
459 unsigned long gmap_translate(struct gmap
*gmap
, unsigned long gaddr
)
463 down_read(&gmap
->mm
->mmap_sem
);
464 rc
= __gmap_translate(gmap
, gaddr
);
465 up_read(&gmap
->mm
->mmap_sem
);
468 EXPORT_SYMBOL_GPL(gmap_translate
);
471 * gmap_unlink - disconnect a page table from the gmap shadow tables
472 * @gmap: pointer to guest mapping meta data structure
473 * @table: pointer to the host page table
474 * @vmaddr: vm address associated with the host page table
476 static void gmap_unlink(struct mm_struct
*mm
, unsigned long *table
,
477 unsigned long vmaddr
)
482 list_for_each_entry(gmap
, &mm
->context
.gmap_list
, list
) {
483 flush
= __gmap_unlink_by_vmaddr(gmap
, vmaddr
);
485 gmap_flush_tlb(gmap
);
490 * gmap_link - set up shadow page tables to connect a host to a guest address
491 * @gmap: pointer to guest mapping meta data structure
492 * @gaddr: guest address
493 * @vmaddr: vm address
495 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
496 * if the vm address is already mapped to a different guest segment.
497 * The mmap_sem of the mm that belongs to the address space must be held
498 * when this function gets called.
500 int __gmap_link(struct gmap
*gmap
, unsigned long gaddr
, unsigned long vmaddr
)
502 struct mm_struct
*mm
;
503 unsigned long *table
;
510 /* Create higher level tables in the gmap page table */
512 if ((gmap
->asce
& _ASCE_TYPE_MASK
) >= _ASCE_TYPE_REGION1
) {
513 table
+= (gaddr
>> 53) & 0x7ff;
514 if ((*table
& _REGION_ENTRY_INVALID
) &&
515 gmap_alloc_table(gmap
, table
, _REGION2_ENTRY_EMPTY
,
516 gaddr
& 0xffe0000000000000UL
))
518 table
= (unsigned long *)(*table
& _REGION_ENTRY_ORIGIN
);
520 if ((gmap
->asce
& _ASCE_TYPE_MASK
) >= _ASCE_TYPE_REGION2
) {
521 table
+= (gaddr
>> 42) & 0x7ff;
522 if ((*table
& _REGION_ENTRY_INVALID
) &&
523 gmap_alloc_table(gmap
, table
, _REGION3_ENTRY_EMPTY
,
524 gaddr
& 0xfffffc0000000000UL
))
526 table
= (unsigned long *)(*table
& _REGION_ENTRY_ORIGIN
);
528 if ((gmap
->asce
& _ASCE_TYPE_MASK
) >= _ASCE_TYPE_REGION3
) {
529 table
+= (gaddr
>> 31) & 0x7ff;
530 if ((*table
& _REGION_ENTRY_INVALID
) &&
531 gmap_alloc_table(gmap
, table
, _SEGMENT_ENTRY_EMPTY
,
532 gaddr
& 0xffffffff80000000UL
))
534 table
= (unsigned long *)(*table
& _REGION_ENTRY_ORIGIN
);
536 table
+= (gaddr
>> 20) & 0x7ff;
537 /* Walk the parent mm page table */
539 pgd
= pgd_offset(mm
, vmaddr
);
540 VM_BUG_ON(pgd_none(*pgd
));
541 pud
= pud_offset(pgd
, vmaddr
);
542 VM_BUG_ON(pud_none(*pud
));
543 pmd
= pmd_offset(pud
, vmaddr
);
544 VM_BUG_ON(pmd_none(*pmd
));
545 /* large pmds cannot yet be handled */
548 /* Link gmap segment table entry location to page table. */
549 rc
= radix_tree_preload(GFP_KERNEL
);
552 ptl
= pmd_lock(mm
, pmd
);
553 spin_lock(&gmap
->guest_table_lock
);
554 if (*table
== _SEGMENT_ENTRY_INVALID
) {
555 rc
= radix_tree_insert(&gmap
->host_to_guest
,
556 vmaddr
>> PMD_SHIFT
, table
);
558 *table
= pmd_val(*pmd
);
561 spin_unlock(&gmap
->guest_table_lock
);
563 radix_tree_preload_end();
568 * gmap_fault - resolve a fault on a guest address
569 * @gmap: pointer to guest mapping meta data structure
570 * @gaddr: guest address
571 * @fault_flags: flags to pass down to handle_mm_fault()
573 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
574 * if the vm address is already mapped to a different guest segment.
576 int gmap_fault(struct gmap
*gmap
, unsigned long gaddr
,
577 unsigned int fault_flags
)
579 unsigned long vmaddr
;
583 down_read(&gmap
->mm
->mmap_sem
);
587 vmaddr
= __gmap_translate(gmap
, gaddr
);
588 if (IS_ERR_VALUE(vmaddr
)) {
592 if (fixup_user_fault(current
, gmap
->mm
, vmaddr
, fault_flags
,
598 * In the case that fixup_user_fault unlocked the mmap_sem during
599 * faultin redo __gmap_translate to not race with a map/unmap_segment.
604 rc
= __gmap_link(gmap
, gaddr
, vmaddr
);
606 up_read(&gmap
->mm
->mmap_sem
);
609 EXPORT_SYMBOL_GPL(gmap_fault
);
611 static void gmap_zap_swap_entry(swp_entry_t entry
, struct mm_struct
*mm
)
613 if (!non_swap_entry(entry
))
614 dec_mm_counter(mm
, MM_SWAPENTS
);
615 else if (is_migration_entry(entry
)) {
616 struct page
*page
= migration_entry_to_page(entry
);
618 dec_mm_counter(mm
, mm_counter(page
));
620 free_swap_and_cache(entry
);
624 * this function is assumed to be called with mmap_sem held
626 void __gmap_zap(struct gmap
*gmap
, unsigned long gaddr
)
628 unsigned long vmaddr
, ptev
, pgstev
;
633 /* Find the vm address for the guest address */
634 vmaddr
= (unsigned long) radix_tree_lookup(&gmap
->guest_to_host
,
638 vmaddr
|= gaddr
& ~PMD_MASK
;
639 /* Get pointer to the page table entry */
640 ptep
= get_locked_pte(gmap
->mm
, vmaddr
, &ptl
);
646 /* Zap unused and logically-zero pages */
647 pgste
= pgste_get_lock(ptep
);
648 pgstev
= pgste_val(pgste
);
650 if (((pgstev
& _PGSTE_GPS_USAGE_MASK
) == _PGSTE_GPS_USAGE_UNUSED
) ||
651 ((pgstev
& _PGSTE_GPS_ZERO
) && (ptev
& _PAGE_INVALID
))) {
652 gmap_zap_swap_entry(pte_to_swp_entry(pte
), gmap
->mm
);
653 pte_clear(gmap
->mm
, vmaddr
, ptep
);
655 pgste_set_unlock(ptep
, pgste
);
657 pte_unmap_unlock(ptep
, ptl
);
659 EXPORT_SYMBOL_GPL(__gmap_zap
);
661 void gmap_discard(struct gmap
*gmap
, unsigned long from
, unsigned long to
)
663 unsigned long gaddr
, vmaddr
, size
;
664 struct vm_area_struct
*vma
;
666 down_read(&gmap
->mm
->mmap_sem
);
667 for (gaddr
= from
; gaddr
< to
;
668 gaddr
= (gaddr
+ PMD_SIZE
) & PMD_MASK
) {
669 /* Find the vm address for the guest address */
670 vmaddr
= (unsigned long)
671 radix_tree_lookup(&gmap
->guest_to_host
,
675 vmaddr
|= gaddr
& ~PMD_MASK
;
676 /* Find vma in the parent mm */
677 vma
= find_vma(gmap
->mm
, vmaddr
);
678 size
= min(to
- gaddr
, PMD_SIZE
- (gaddr
& ~PMD_MASK
));
679 zap_page_range(vma
, vmaddr
, size
, NULL
);
681 up_read(&gmap
->mm
->mmap_sem
);
683 EXPORT_SYMBOL_GPL(gmap_discard
);
685 static LIST_HEAD(gmap_notifier_list
);
686 static DEFINE_SPINLOCK(gmap_notifier_lock
);
689 * gmap_register_ipte_notifier - register a pte invalidation callback
690 * @nb: pointer to the gmap notifier block
692 void gmap_register_ipte_notifier(struct gmap_notifier
*nb
)
694 spin_lock(&gmap_notifier_lock
);
695 list_add(&nb
->list
, &gmap_notifier_list
);
696 spin_unlock(&gmap_notifier_lock
);
698 EXPORT_SYMBOL_GPL(gmap_register_ipte_notifier
);
701 * gmap_unregister_ipte_notifier - remove a pte invalidation callback
702 * @nb: pointer to the gmap notifier block
704 void gmap_unregister_ipte_notifier(struct gmap_notifier
*nb
)
706 spin_lock(&gmap_notifier_lock
);
707 list_del_init(&nb
->list
);
708 spin_unlock(&gmap_notifier_lock
);
710 EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier
);
713 * gmap_ipte_notify - mark a range of ptes for invalidation notification
714 * @gmap: pointer to guest mapping meta data structure
715 * @gaddr: virtual address in the guest address space
718 * Returns 0 if for each page in the given range a gmap mapping exists and
719 * the invalidation notification could be set. If the gmap mapping is missing
720 * for one or more pages -EFAULT is returned. If no memory could be allocated
721 * -ENOMEM is returned. This function establishes missing page table entries.
723 int gmap_ipte_notify(struct gmap
*gmap
, unsigned long gaddr
, unsigned long len
)
732 if ((gaddr
& ~PAGE_MASK
) || (len
& ~PAGE_MASK
))
734 down_read(&gmap
->mm
->mmap_sem
);
737 /* Convert gmap address and connect the page tables */
738 addr
= __gmap_translate(gmap
, gaddr
);
739 if (IS_ERR_VALUE(addr
)) {
743 /* Get the page mapped */
744 if (fixup_user_fault(current
, gmap
->mm
, addr
, FAULT_FLAG_WRITE
,
749 /* While trying to map mmap_sem got unlocked. Let us retry */
752 rc
= __gmap_link(gmap
, gaddr
, addr
);
755 /* Walk the process page table, lock and get pte pointer */
756 ptep
= get_locked_pte(gmap
->mm
, addr
, &ptl
);
758 /* Set notification bit in the pgste of the pte */
760 if ((pte_val(entry
) & (_PAGE_INVALID
| _PAGE_PROTECT
)) == 0) {
761 pgste
= pgste_get_lock(ptep
);
762 pgste_val(pgste
) |= PGSTE_IN_BIT
;
763 pgste_set_unlock(ptep
, pgste
);
767 pte_unmap_unlock(ptep
, ptl
);
769 up_read(&gmap
->mm
->mmap_sem
);
772 EXPORT_SYMBOL_GPL(gmap_ipte_notify
);
775 * gmap_do_ipte_notify - call all invalidation callbacks for a specific pte.
776 * @mm: pointer to the process mm_struct
777 * @addr: virtual address in the process address space
778 * @pte: pointer to the page table entry
780 * This function is assumed to be called with the page table lock held
781 * for the pte to notify.
783 void gmap_do_ipte_notify(struct mm_struct
*mm
, unsigned long vmaddr
, pte_t
*pte
)
785 unsigned long offset
, gaddr
;
786 unsigned long *table
;
787 struct gmap_notifier
*nb
;
790 offset
= ((unsigned long) pte
) & (255 * sizeof(pte_t
));
791 offset
= offset
* (4096 / sizeof(pte_t
));
792 spin_lock(&gmap_notifier_lock
);
793 list_for_each_entry(gmap
, &mm
->context
.gmap_list
, list
) {
794 table
= radix_tree_lookup(&gmap
->host_to_guest
,
795 vmaddr
>> PMD_SHIFT
);
798 gaddr
= __gmap_segment_gaddr(table
) + offset
;
799 list_for_each_entry(nb
, &gmap_notifier_list
, list
)
800 nb
->notifier_call(gmap
, gaddr
);
802 spin_unlock(&gmap_notifier_lock
);
804 EXPORT_SYMBOL_GPL(gmap_do_ipte_notify
);
806 int set_guest_storage_key(struct mm_struct
*mm
, unsigned long addr
,
807 unsigned long key
, bool nq
)
814 down_read(&mm
->mmap_sem
);
817 ptep
= get_locked_pte(mm
, addr
, &ptl
);
818 if (unlikely(!ptep
)) {
819 up_read(&mm
->mmap_sem
);
822 if (!(pte_val(*ptep
) & _PAGE_INVALID
) &&
823 (pte_val(*ptep
) & _PAGE_PROTECT
)) {
824 pte_unmap_unlock(ptep
, ptl
);
826 * We do not really care about unlocked. We will retry either
827 * way. But this allows fixup_user_fault to enable userfaultfd.
829 if (fixup_user_fault(current
, mm
, addr
, FAULT_FLAG_WRITE
,
831 up_read(&mm
->mmap_sem
);
837 new = old
= pgste_get_lock(ptep
);
838 pgste_val(new) &= ~(PGSTE_GR_BIT
| PGSTE_GC_BIT
|
839 PGSTE_ACC_BITS
| PGSTE_FP_BIT
);
840 pgste_val(new) |= (key
& (_PAGE_CHANGED
| _PAGE_REFERENCED
)) << 48;
841 pgste_val(new) |= (key
& (_PAGE_ACC_BITS
| _PAGE_FP_BIT
)) << 56;
842 if (!(pte_val(*ptep
) & _PAGE_INVALID
)) {
843 unsigned long address
, bits
, skey
;
845 address
= pte_val(*ptep
) & PAGE_MASK
;
846 skey
= (unsigned long) page_get_storage_key(address
);
847 bits
= skey
& (_PAGE_CHANGED
| _PAGE_REFERENCED
);
848 skey
= key
& (_PAGE_ACC_BITS
| _PAGE_FP_BIT
);
849 /* Set storage key ACC and FP */
850 page_set_storage_key(address
, skey
, !nq
);
851 /* Merge host changed & referenced into pgste */
852 pgste_val(new) |= bits
<< 52;
854 /* changing the guest storage key is considered a change of the page */
855 if ((pgste_val(new) ^ pgste_val(old
)) &
856 (PGSTE_ACC_BITS
| PGSTE_FP_BIT
| PGSTE_GR_BIT
| PGSTE_GC_BIT
))
857 pgste_val(new) |= PGSTE_UC_BIT
;
859 pgste_set_unlock(ptep
, new);
860 pte_unmap_unlock(ptep
, ptl
);
861 up_read(&mm
->mmap_sem
);
864 EXPORT_SYMBOL(set_guest_storage_key
);
866 unsigned long get_guest_storage_key(struct mm_struct
*mm
, unsigned long addr
)
872 unsigned long key
= 0;
874 down_read(&mm
->mmap_sem
);
875 ptep
= get_locked_pte(mm
, addr
, &ptl
);
876 if (unlikely(!ptep
)) {
877 up_read(&mm
->mmap_sem
);
880 pgste
= pgste_get_lock(ptep
);
882 if (pte_val(*ptep
) & _PAGE_INVALID
) {
883 key
|= (pgste_val(pgste
) & PGSTE_ACC_BITS
) >> 56;
884 key
|= (pgste_val(pgste
) & PGSTE_FP_BIT
) >> 56;
885 key
|= (pgste_val(pgste
) & PGSTE_GR_BIT
) >> 48;
886 key
|= (pgste_val(pgste
) & PGSTE_GC_BIT
) >> 48;
888 physaddr
= pte_val(*ptep
) & PAGE_MASK
;
889 key
= page_get_storage_key(physaddr
);
891 /* Reflect guest's logical view, not physical */
892 if (pgste_val(pgste
) & PGSTE_GR_BIT
)
893 key
|= _PAGE_REFERENCED
;
894 if (pgste_val(pgste
) & PGSTE_GC_BIT
)
895 key
|= _PAGE_CHANGED
;
898 pgste_set_unlock(ptep
, pgste
);
899 pte_unmap_unlock(ptep
, ptl
);
900 up_read(&mm
->mmap_sem
);
903 EXPORT_SYMBOL(get_guest_storage_key
);
905 static int page_table_allocate_pgste_min
= 0;
906 static int page_table_allocate_pgste_max
= 1;
907 int page_table_allocate_pgste
= 0;
908 EXPORT_SYMBOL(page_table_allocate_pgste
);
910 static struct ctl_table page_table_sysctl
[] = {
912 .procname
= "allocate_pgste",
913 .data
= &page_table_allocate_pgste
,
914 .maxlen
= sizeof(int),
915 .mode
= S_IRUGO
| S_IWUSR
,
916 .proc_handler
= proc_dointvec
,
917 .extra1
= &page_table_allocate_pgste_min
,
918 .extra2
= &page_table_allocate_pgste_max
,
923 static struct ctl_table page_table_sysctl_dir
[] = {
928 .child
= page_table_sysctl
,
933 static int __init
page_table_register_sysctl(void)
935 return register_sysctl_table(page_table_sysctl_dir
) ? 0 : -ENOMEM
;
937 __initcall(page_table_register_sysctl
);
939 #else /* CONFIG_PGSTE */
941 static inline void gmap_unlink(struct mm_struct
*mm
, unsigned long *table
,
942 unsigned long vmaddr
)
946 #endif /* CONFIG_PGSTE */
948 static inline unsigned int atomic_xor_bits(atomic_t
*v
, unsigned int bits
)
950 unsigned int old
, new;
953 old
= atomic_read(v
);
955 } while (atomic_cmpxchg(v
, old
, new) != old
);
960 * page table entry allocation/free routines.
962 unsigned long *page_table_alloc(struct mm_struct
*mm
)
964 unsigned long *table
;
966 unsigned int mask
, bit
;
968 /* Try to get a fragment of a 4K page as a 2K page table */
969 if (!mm_alloc_pgste(mm
)) {
971 spin_lock_bh(&mm
->context
.list_lock
);
972 if (!list_empty(&mm
->context
.pgtable_list
)) {
973 page
= list_first_entry(&mm
->context
.pgtable_list
,
975 mask
= atomic_read(&page
->_mapcount
);
976 mask
= (mask
| (mask
>> 4)) & 3;
978 table
= (unsigned long *) page_to_phys(page
);
979 bit
= mask
& 1; /* =1 -> second 2K */
981 table
+= PTRS_PER_PTE
;
982 atomic_xor_bits(&page
->_mapcount
, 1U << bit
);
983 list_del(&page
->lru
);
986 spin_unlock_bh(&mm
->context
.list_lock
);
990 /* Allocate a fresh page */
991 page
= alloc_page(GFP_KERNEL
|__GFP_REPEAT
);
994 if (!pgtable_page_ctor(page
)) {
998 /* Initialize page table */
999 table
= (unsigned long *) page_to_phys(page
);
1000 if (mm_alloc_pgste(mm
)) {
1001 /* Return 4K page table with PGSTEs */
1002 atomic_set(&page
->_mapcount
, 3);
1003 clear_table(table
, _PAGE_INVALID
, PAGE_SIZE
/2);
1004 clear_table(table
+ PTRS_PER_PTE
, 0, PAGE_SIZE
/2);
1006 /* Return the first 2K fragment of the page */
1007 atomic_set(&page
->_mapcount
, 1);
1008 clear_table(table
, _PAGE_INVALID
, PAGE_SIZE
);
1009 spin_lock_bh(&mm
->context
.list_lock
);
1010 list_add(&page
->lru
, &mm
->context
.pgtable_list
);
1011 spin_unlock_bh(&mm
->context
.list_lock
);
1016 void page_table_free(struct mm_struct
*mm
, unsigned long *table
)
1019 unsigned int bit
, mask
;
1021 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1022 if (!mm_alloc_pgste(mm
)) {
1023 /* Free 2K page table fragment of a 4K page */
1024 bit
= (__pa(table
) & ~PAGE_MASK
)/(PTRS_PER_PTE
*sizeof(pte_t
));
1025 spin_lock_bh(&mm
->context
.list_lock
);
1026 mask
= atomic_xor_bits(&page
->_mapcount
, 1U << bit
);
1028 list_add(&page
->lru
, &mm
->context
.pgtable_list
);
1030 list_del(&page
->lru
);
1031 spin_unlock_bh(&mm
->context
.list_lock
);
1036 pgtable_page_dtor(page
);
1037 atomic_set(&page
->_mapcount
, -1);
1041 void page_table_free_rcu(struct mmu_gather
*tlb
, unsigned long *table
,
1042 unsigned long vmaddr
)
1044 struct mm_struct
*mm
;
1046 unsigned int bit
, mask
;
1049 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1050 if (mm_alloc_pgste(mm
)) {
1051 gmap_unlink(mm
, table
, vmaddr
);
1052 table
= (unsigned long *) (__pa(table
) | 3);
1053 tlb_remove_table(tlb
, table
);
1056 bit
= (__pa(table
) & ~PAGE_MASK
) / (PTRS_PER_PTE
*sizeof(pte_t
));
1057 spin_lock_bh(&mm
->context
.list_lock
);
1058 mask
= atomic_xor_bits(&page
->_mapcount
, 0x11U
<< bit
);
1060 list_add_tail(&page
->lru
, &mm
->context
.pgtable_list
);
1062 list_del(&page
->lru
);
1063 spin_unlock_bh(&mm
->context
.list_lock
);
1064 table
= (unsigned long *) (__pa(table
) | (1U << bit
));
1065 tlb_remove_table(tlb
, table
);
1068 static void __tlb_remove_table(void *_table
)
1070 unsigned int mask
= (unsigned long) _table
& 3;
1071 void *table
= (void *)((unsigned long) _table
^ mask
);
1072 struct page
*page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1075 case 0: /* pmd or pud */
1076 free_pages((unsigned long) table
, 2);
1078 case 1: /* lower 2K of a 4K page table */
1079 case 2: /* higher 2K of a 4K page table */
1080 if (atomic_xor_bits(&page
->_mapcount
, mask
<< 4) != 0)
1083 case 3: /* 4K page table with pgstes */
1084 pgtable_page_dtor(page
);
1085 atomic_set(&page
->_mapcount
, -1);
1091 static void tlb_remove_table_smp_sync(void *arg
)
1093 /* Simply deliver the interrupt */
1096 static void tlb_remove_table_one(void *table
)
1099 * This isn't an RCU grace period and hence the page-tables cannot be
1100 * assumed to be actually RCU-freed.
1102 * It is however sufficient for software page-table walkers that rely
1103 * on IRQ disabling. See the comment near struct mmu_table_batch.
1105 smp_call_function(tlb_remove_table_smp_sync
, NULL
, 1);
1106 __tlb_remove_table(table
);
1109 static void tlb_remove_table_rcu(struct rcu_head
*head
)
1111 struct mmu_table_batch
*batch
;
1114 batch
= container_of(head
, struct mmu_table_batch
, rcu
);
1116 for (i
= 0; i
< batch
->nr
; i
++)
1117 __tlb_remove_table(batch
->tables
[i
]);
1119 free_page((unsigned long)batch
);
1122 void tlb_table_flush(struct mmu_gather
*tlb
)
1124 struct mmu_table_batch
**batch
= &tlb
->batch
;
1127 call_rcu_sched(&(*batch
)->rcu
, tlb_remove_table_rcu
);
1132 void tlb_remove_table(struct mmu_gather
*tlb
, void *table
)
1134 struct mmu_table_batch
**batch
= &tlb
->batch
;
1136 tlb
->mm
->context
.flush_mm
= 1;
1137 if (*batch
== NULL
) {
1138 *batch
= (struct mmu_table_batch
*)
1139 __get_free_page(GFP_NOWAIT
| __GFP_NOWARN
);
1140 if (*batch
== NULL
) {
1141 __tlb_flush_mm_lazy(tlb
->mm
);
1142 tlb_remove_table_one(table
);
1147 (*batch
)->tables
[(*batch
)->nr
++] = table
;
1148 if ((*batch
)->nr
== MAX_TABLE_BATCH
)
1152 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1153 static inline void thp_split_vma(struct vm_area_struct
*vma
)
1157 for (addr
= vma
->vm_start
; addr
< vma
->vm_end
; addr
+= PAGE_SIZE
)
1158 follow_page(vma
, addr
, FOLL_SPLIT
);
1161 static inline void thp_split_mm(struct mm_struct
*mm
)
1163 struct vm_area_struct
*vma
;
1165 for (vma
= mm
->mmap
; vma
!= NULL
; vma
= vma
->vm_next
) {
1167 vma
->vm_flags
&= ~VM_HUGEPAGE
;
1168 vma
->vm_flags
|= VM_NOHUGEPAGE
;
1170 mm
->def_flags
|= VM_NOHUGEPAGE
;
1173 static inline void thp_split_mm(struct mm_struct
*mm
)
1176 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1179 * switch on pgstes for its userspace process (for kvm)
1181 int s390_enable_sie(void)
1183 struct mm_struct
*mm
= current
->mm
;
1185 /* Do we have pgstes? if yes, we are done */
1186 if (mm_has_pgste(mm
))
1188 /* Fail if the page tables are 2K */
1189 if (!mm_alloc_pgste(mm
))
1191 down_write(&mm
->mmap_sem
);
1192 mm
->context
.has_pgste
= 1;
1193 /* split thp mappings and disable thp for future mappings */
1195 up_write(&mm
->mmap_sem
);
1198 EXPORT_SYMBOL_GPL(s390_enable_sie
);
1201 * Enable storage key handling from now on and initialize the storage
1202 * keys with the default key.
1204 static int __s390_enable_skey(pte_t
*pte
, unsigned long addr
,
1205 unsigned long next
, struct mm_walk
*walk
)
1210 pgste
= pgste_get_lock(pte
);
1212 * Remove all zero page mappings,
1213 * after establishing a policy to forbid zero page mappings
1214 * following faults for that page will get fresh anonymous pages
1216 if (is_zero_pfn(pte_pfn(*pte
))) {
1217 ptep_flush_direct(walk
->mm
, addr
, pte
);
1218 pte_val(*pte
) = _PAGE_INVALID
;
1220 /* Clear storage key */
1221 pgste_val(pgste
) &= ~(PGSTE_ACC_BITS
| PGSTE_FP_BIT
|
1222 PGSTE_GR_BIT
| PGSTE_GC_BIT
);
1223 ptev
= pte_val(*pte
);
1224 if (!(ptev
& _PAGE_INVALID
) && (ptev
& _PAGE_WRITE
))
1225 page_set_storage_key(ptev
& PAGE_MASK
, PAGE_DEFAULT_KEY
, 1);
1226 pgste_set_unlock(pte
, pgste
);
1230 int s390_enable_skey(void)
1232 struct mm_walk walk
= { .pte_entry
= __s390_enable_skey
};
1233 struct mm_struct
*mm
= current
->mm
;
1234 struct vm_area_struct
*vma
;
1237 down_write(&mm
->mmap_sem
);
1238 if (mm_use_skey(mm
))
1241 mm
->context
.use_skey
= 1;
1242 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
1243 if (ksm_madvise(vma
, vma
->vm_start
, vma
->vm_end
,
1244 MADV_UNMERGEABLE
, &vma
->vm_flags
)) {
1245 mm
->context
.use_skey
= 0;
1250 mm
->def_flags
&= ~VM_MERGEABLE
;
1253 walk_page_range(0, TASK_SIZE
, &walk
);
1256 up_write(&mm
->mmap_sem
);
1259 EXPORT_SYMBOL_GPL(s390_enable_skey
);
1262 * Reset CMMA state, make all pages stable again.
1264 static int __s390_reset_cmma(pte_t
*pte
, unsigned long addr
,
1265 unsigned long next
, struct mm_walk
*walk
)
1269 pgste
= pgste_get_lock(pte
);
1270 pgste_val(pgste
) &= ~_PGSTE_GPS_USAGE_MASK
;
1271 pgste_set_unlock(pte
, pgste
);
1275 void s390_reset_cmma(struct mm_struct
*mm
)
1277 struct mm_walk walk
= { .pte_entry
= __s390_reset_cmma
};
1279 down_write(&mm
->mmap_sem
);
1281 walk_page_range(0, TASK_SIZE
, &walk
);
1282 up_write(&mm
->mmap_sem
);
1284 EXPORT_SYMBOL_GPL(s390_reset_cmma
);
1287 * Test and reset if a guest page is dirty
1289 bool gmap_test_and_clear_dirty(unsigned long address
, struct gmap
*gmap
)
1295 pte
= get_locked_pte(gmap
->mm
, address
, &ptl
);
1299 if (ptep_test_and_clear_user_dirty(gmap
->mm
, address
, pte
))
1305 EXPORT_SYMBOL_GPL(gmap_test_and_clear_dirty
);
1307 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1308 int pmdp_clear_flush_young(struct vm_area_struct
*vma
, unsigned long address
,
1311 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1312 /* No need to flush TLB
1313 * On s390 reference bits are in storage key and never in TLB */
1314 return pmdp_test_and_clear_young(vma
, address
, pmdp
);
1317 int pmdp_set_access_flags(struct vm_area_struct
*vma
,
1318 unsigned long address
, pmd_t
*pmdp
,
1319 pmd_t entry
, int dirty
)
1321 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1323 entry
= pmd_mkyoung(entry
);
1325 entry
= pmd_mkdirty(entry
);
1326 if (pmd_same(*pmdp
, entry
))
1328 pmdp_invalidate(vma
, address
, pmdp
);
1329 set_pmd_at(vma
->vm_mm
, address
, pmdp
, entry
);
1333 void pgtable_trans_huge_deposit(struct mm_struct
*mm
, pmd_t
*pmdp
,
1336 struct list_head
*lh
= (struct list_head
*) pgtable
;
1338 assert_spin_locked(pmd_lockptr(mm
, pmdp
));
1341 if (!pmd_huge_pte(mm
, pmdp
))
1344 list_add(lh
, (struct list_head
*) pmd_huge_pte(mm
, pmdp
));
1345 pmd_huge_pte(mm
, pmdp
) = pgtable
;
1348 pgtable_t
pgtable_trans_huge_withdraw(struct mm_struct
*mm
, pmd_t
*pmdp
)
1350 struct list_head
*lh
;
1354 assert_spin_locked(pmd_lockptr(mm
, pmdp
));
1357 pgtable
= pmd_huge_pte(mm
, pmdp
);
1358 lh
= (struct list_head
*) pgtable
;
1360 pmd_huge_pte(mm
, pmdp
) = NULL
;
1362 pmd_huge_pte(mm
, pmdp
) = (pgtable_t
) lh
->next
;
1365 ptep
= (pte_t
*) pgtable
;
1366 pte_val(*ptep
) = _PAGE_INVALID
;
1368 pte_val(*ptep
) = _PAGE_INVALID
;
1371 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */