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
> (1UL << 53));
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
;
582 down_read(&gmap
->mm
->mmap_sem
);
583 vmaddr
= __gmap_translate(gmap
, gaddr
);
584 if (IS_ERR_VALUE(vmaddr
)) {
588 if (fixup_user_fault(current
, gmap
->mm
, vmaddr
, fault_flags
)) {
592 rc
= __gmap_link(gmap
, gaddr
, vmaddr
);
594 up_read(&gmap
->mm
->mmap_sem
);
597 EXPORT_SYMBOL_GPL(gmap_fault
);
599 static void gmap_zap_swap_entry(swp_entry_t entry
, struct mm_struct
*mm
)
601 if (!non_swap_entry(entry
))
602 dec_mm_counter(mm
, MM_SWAPENTS
);
603 else if (is_migration_entry(entry
)) {
604 struct page
*page
= migration_entry_to_page(entry
);
606 dec_mm_counter(mm
, mm_counter(page
));
608 free_swap_and_cache(entry
);
612 * this function is assumed to be called with mmap_sem held
614 void __gmap_zap(struct gmap
*gmap
, unsigned long gaddr
)
616 unsigned long vmaddr
, ptev
, pgstev
;
621 /* Find the vm address for the guest address */
622 vmaddr
= (unsigned long) radix_tree_lookup(&gmap
->guest_to_host
,
626 vmaddr
|= gaddr
& ~PMD_MASK
;
627 /* Get pointer to the page table entry */
628 ptep
= get_locked_pte(gmap
->mm
, vmaddr
, &ptl
);
634 /* Zap unused and logically-zero pages */
635 pgste
= pgste_get_lock(ptep
);
636 pgstev
= pgste_val(pgste
);
638 if (((pgstev
& _PGSTE_GPS_USAGE_MASK
) == _PGSTE_GPS_USAGE_UNUSED
) ||
639 ((pgstev
& _PGSTE_GPS_ZERO
) && (ptev
& _PAGE_INVALID
))) {
640 gmap_zap_swap_entry(pte_to_swp_entry(pte
), gmap
->mm
);
641 pte_clear(gmap
->mm
, vmaddr
, ptep
);
643 pgste_set_unlock(ptep
, pgste
);
645 pte_unmap_unlock(ptep
, ptl
);
647 EXPORT_SYMBOL_GPL(__gmap_zap
);
649 void gmap_discard(struct gmap
*gmap
, unsigned long from
, unsigned long to
)
651 unsigned long gaddr
, vmaddr
, size
;
652 struct vm_area_struct
*vma
;
654 down_read(&gmap
->mm
->mmap_sem
);
655 for (gaddr
= from
; gaddr
< to
;
656 gaddr
= (gaddr
+ PMD_SIZE
) & PMD_MASK
) {
657 /* Find the vm address for the guest address */
658 vmaddr
= (unsigned long)
659 radix_tree_lookup(&gmap
->guest_to_host
,
663 vmaddr
|= gaddr
& ~PMD_MASK
;
664 /* Find vma in the parent mm */
665 vma
= find_vma(gmap
->mm
, vmaddr
);
666 size
= min(to
- gaddr
, PMD_SIZE
- (gaddr
& ~PMD_MASK
));
667 zap_page_range(vma
, vmaddr
, size
, NULL
);
669 up_read(&gmap
->mm
->mmap_sem
);
671 EXPORT_SYMBOL_GPL(gmap_discard
);
673 static LIST_HEAD(gmap_notifier_list
);
674 static DEFINE_SPINLOCK(gmap_notifier_lock
);
677 * gmap_register_ipte_notifier - register a pte invalidation callback
678 * @nb: pointer to the gmap notifier block
680 void gmap_register_ipte_notifier(struct gmap_notifier
*nb
)
682 spin_lock(&gmap_notifier_lock
);
683 list_add(&nb
->list
, &gmap_notifier_list
);
684 spin_unlock(&gmap_notifier_lock
);
686 EXPORT_SYMBOL_GPL(gmap_register_ipte_notifier
);
689 * gmap_unregister_ipte_notifier - remove a pte invalidation callback
690 * @nb: pointer to the gmap notifier block
692 void gmap_unregister_ipte_notifier(struct gmap_notifier
*nb
)
694 spin_lock(&gmap_notifier_lock
);
695 list_del_init(&nb
->list
);
696 spin_unlock(&gmap_notifier_lock
);
698 EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier
);
701 * gmap_ipte_notify - mark a range of ptes for invalidation notification
702 * @gmap: pointer to guest mapping meta data structure
703 * @gaddr: virtual address in the guest address space
706 * Returns 0 if for each page in the given range a gmap mapping exists and
707 * the invalidation notification could be set. If the gmap mapping is missing
708 * for one or more pages -EFAULT is returned. If no memory could be allocated
709 * -ENOMEM is returned. This function establishes missing page table entries.
711 int gmap_ipte_notify(struct gmap
*gmap
, unsigned long gaddr
, unsigned long len
)
719 if ((gaddr
& ~PAGE_MASK
) || (len
& ~PAGE_MASK
))
721 down_read(&gmap
->mm
->mmap_sem
);
723 /* Convert gmap address and connect the page tables */
724 addr
= __gmap_translate(gmap
, gaddr
);
725 if (IS_ERR_VALUE(addr
)) {
729 /* Get the page mapped */
730 if (fixup_user_fault(current
, gmap
->mm
, addr
, FAULT_FLAG_WRITE
)) {
734 rc
= __gmap_link(gmap
, gaddr
, addr
);
737 /* Walk the process page table, lock and get pte pointer */
738 ptep
= get_locked_pte(gmap
->mm
, addr
, &ptl
);
740 /* Set notification bit in the pgste of the pte */
742 if ((pte_val(entry
) & (_PAGE_INVALID
| _PAGE_PROTECT
)) == 0) {
743 pgste
= pgste_get_lock(ptep
);
744 pgste_val(pgste
) |= PGSTE_IN_BIT
;
745 pgste_set_unlock(ptep
, pgste
);
749 pte_unmap_unlock(ptep
, ptl
);
751 up_read(&gmap
->mm
->mmap_sem
);
754 EXPORT_SYMBOL_GPL(gmap_ipte_notify
);
757 * gmap_do_ipte_notify - call all invalidation callbacks for a specific pte.
758 * @mm: pointer to the process mm_struct
759 * @addr: virtual address in the process address space
760 * @pte: pointer to the page table entry
762 * This function is assumed to be called with the page table lock held
763 * for the pte to notify.
765 void gmap_do_ipte_notify(struct mm_struct
*mm
, unsigned long vmaddr
, pte_t
*pte
)
767 unsigned long offset
, gaddr
;
768 unsigned long *table
;
769 struct gmap_notifier
*nb
;
772 offset
= ((unsigned long) pte
) & (255 * sizeof(pte_t
));
773 offset
= offset
* (4096 / sizeof(pte_t
));
774 spin_lock(&gmap_notifier_lock
);
775 list_for_each_entry(gmap
, &mm
->context
.gmap_list
, list
) {
776 table
= radix_tree_lookup(&gmap
->host_to_guest
,
777 vmaddr
>> PMD_SHIFT
);
780 gaddr
= __gmap_segment_gaddr(table
) + offset
;
781 list_for_each_entry(nb
, &gmap_notifier_list
, list
)
782 nb
->notifier_call(gmap
, gaddr
);
784 spin_unlock(&gmap_notifier_lock
);
786 EXPORT_SYMBOL_GPL(gmap_do_ipte_notify
);
788 int set_guest_storage_key(struct mm_struct
*mm
, unsigned long addr
,
789 unsigned long key
, bool nq
)
795 down_read(&mm
->mmap_sem
);
797 ptep
= get_locked_pte(mm
, addr
, &ptl
);
798 if (unlikely(!ptep
)) {
799 up_read(&mm
->mmap_sem
);
802 if (!(pte_val(*ptep
) & _PAGE_INVALID
) &&
803 (pte_val(*ptep
) & _PAGE_PROTECT
)) {
804 pte_unmap_unlock(ptep
, ptl
);
805 if (fixup_user_fault(current
, mm
, addr
, FAULT_FLAG_WRITE
)) {
806 up_read(&mm
->mmap_sem
);
812 new = old
= pgste_get_lock(ptep
);
813 pgste_val(new) &= ~(PGSTE_GR_BIT
| PGSTE_GC_BIT
|
814 PGSTE_ACC_BITS
| PGSTE_FP_BIT
);
815 pgste_val(new) |= (key
& (_PAGE_CHANGED
| _PAGE_REFERENCED
)) << 48;
816 pgste_val(new) |= (key
& (_PAGE_ACC_BITS
| _PAGE_FP_BIT
)) << 56;
817 if (!(pte_val(*ptep
) & _PAGE_INVALID
)) {
818 unsigned long address
, bits
, skey
;
820 address
= pte_val(*ptep
) & PAGE_MASK
;
821 skey
= (unsigned long) page_get_storage_key(address
);
822 bits
= skey
& (_PAGE_CHANGED
| _PAGE_REFERENCED
);
823 skey
= key
& (_PAGE_ACC_BITS
| _PAGE_FP_BIT
);
824 /* Set storage key ACC and FP */
825 page_set_storage_key(address
, skey
, !nq
);
826 /* Merge host changed & referenced into pgste */
827 pgste_val(new) |= bits
<< 52;
829 /* changing the guest storage key is considered a change of the page */
830 if ((pgste_val(new) ^ pgste_val(old
)) &
831 (PGSTE_ACC_BITS
| PGSTE_FP_BIT
| PGSTE_GR_BIT
| PGSTE_GC_BIT
))
832 pgste_val(new) |= PGSTE_UC_BIT
;
834 pgste_set_unlock(ptep
, new);
835 pte_unmap_unlock(ptep
, ptl
);
836 up_read(&mm
->mmap_sem
);
839 EXPORT_SYMBOL(set_guest_storage_key
);
841 unsigned long get_guest_storage_key(struct mm_struct
*mm
, unsigned long addr
)
847 unsigned long key
= 0;
849 down_read(&mm
->mmap_sem
);
850 ptep
= get_locked_pte(mm
, addr
, &ptl
);
851 if (unlikely(!ptep
)) {
852 up_read(&mm
->mmap_sem
);
855 pgste
= pgste_get_lock(ptep
);
857 if (pte_val(*ptep
) & _PAGE_INVALID
) {
858 key
|= (pgste_val(pgste
) & PGSTE_ACC_BITS
) >> 56;
859 key
|= (pgste_val(pgste
) & PGSTE_FP_BIT
) >> 56;
860 key
|= (pgste_val(pgste
) & PGSTE_GR_BIT
) >> 48;
861 key
|= (pgste_val(pgste
) & PGSTE_GC_BIT
) >> 48;
863 physaddr
= pte_val(*ptep
) & PAGE_MASK
;
864 key
= page_get_storage_key(physaddr
);
866 /* Reflect guest's logical view, not physical */
867 if (pgste_val(pgste
) & PGSTE_GR_BIT
)
868 key
|= _PAGE_REFERENCED
;
869 if (pgste_val(pgste
) & PGSTE_GC_BIT
)
870 key
|= _PAGE_CHANGED
;
873 pgste_set_unlock(ptep
, pgste
);
874 pte_unmap_unlock(ptep
, ptl
);
875 up_read(&mm
->mmap_sem
);
878 EXPORT_SYMBOL(get_guest_storage_key
);
880 static int page_table_allocate_pgste_min
= 0;
881 static int page_table_allocate_pgste_max
= 1;
882 int page_table_allocate_pgste
= 0;
883 EXPORT_SYMBOL(page_table_allocate_pgste
);
885 static struct ctl_table page_table_sysctl
[] = {
887 .procname
= "allocate_pgste",
888 .data
= &page_table_allocate_pgste
,
889 .maxlen
= sizeof(int),
890 .mode
= S_IRUGO
| S_IWUSR
,
891 .proc_handler
= proc_dointvec
,
892 .extra1
= &page_table_allocate_pgste_min
,
893 .extra2
= &page_table_allocate_pgste_max
,
898 static struct ctl_table page_table_sysctl_dir
[] = {
903 .child
= page_table_sysctl
,
908 static int __init
page_table_register_sysctl(void)
910 return register_sysctl_table(page_table_sysctl_dir
) ? 0 : -ENOMEM
;
912 __initcall(page_table_register_sysctl
);
914 #else /* CONFIG_PGSTE */
916 static inline void gmap_unlink(struct mm_struct
*mm
, unsigned long *table
,
917 unsigned long vmaddr
)
921 #endif /* CONFIG_PGSTE */
923 static inline unsigned int atomic_xor_bits(atomic_t
*v
, unsigned int bits
)
925 unsigned int old
, new;
928 old
= atomic_read(v
);
930 } while (atomic_cmpxchg(v
, old
, new) != old
);
935 * page table entry allocation/free routines.
937 unsigned long *page_table_alloc(struct mm_struct
*mm
)
939 unsigned long *table
;
941 unsigned int mask
, bit
;
943 /* Try to get a fragment of a 4K page as a 2K page table */
944 if (!mm_alloc_pgste(mm
)) {
946 spin_lock_bh(&mm
->context
.list_lock
);
947 if (!list_empty(&mm
->context
.pgtable_list
)) {
948 page
= list_first_entry(&mm
->context
.pgtable_list
,
950 mask
= atomic_read(&page
->_mapcount
);
951 mask
= (mask
| (mask
>> 4)) & 3;
953 table
= (unsigned long *) page_to_phys(page
);
954 bit
= mask
& 1; /* =1 -> second 2K */
956 table
+= PTRS_PER_PTE
;
957 atomic_xor_bits(&page
->_mapcount
, 1U << bit
);
958 list_del(&page
->lru
);
961 spin_unlock_bh(&mm
->context
.list_lock
);
965 /* Allocate a fresh page */
966 page
= alloc_page(GFP_KERNEL
|__GFP_REPEAT
);
969 if (!pgtable_page_ctor(page
)) {
973 /* Initialize page table */
974 table
= (unsigned long *) page_to_phys(page
);
975 if (mm_alloc_pgste(mm
)) {
976 /* Return 4K page table with PGSTEs */
977 atomic_set(&page
->_mapcount
, 3);
978 clear_table(table
, _PAGE_INVALID
, PAGE_SIZE
/2);
979 clear_table(table
+ PTRS_PER_PTE
, 0, PAGE_SIZE
/2);
981 /* Return the first 2K fragment of the page */
982 atomic_set(&page
->_mapcount
, 1);
983 clear_table(table
, _PAGE_INVALID
, PAGE_SIZE
);
984 spin_lock_bh(&mm
->context
.list_lock
);
985 list_add(&page
->lru
, &mm
->context
.pgtable_list
);
986 spin_unlock_bh(&mm
->context
.list_lock
);
991 void page_table_free(struct mm_struct
*mm
, unsigned long *table
)
994 unsigned int bit
, mask
;
996 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
997 if (!mm_alloc_pgste(mm
)) {
998 /* Free 2K page table fragment of a 4K page */
999 bit
= (__pa(table
) & ~PAGE_MASK
)/(PTRS_PER_PTE
*sizeof(pte_t
));
1000 spin_lock_bh(&mm
->context
.list_lock
);
1001 mask
= atomic_xor_bits(&page
->_mapcount
, 1U << bit
);
1003 list_add(&page
->lru
, &mm
->context
.pgtable_list
);
1005 list_del(&page
->lru
);
1006 spin_unlock_bh(&mm
->context
.list_lock
);
1011 pgtable_page_dtor(page
);
1012 atomic_set(&page
->_mapcount
, -1);
1016 void page_table_free_rcu(struct mmu_gather
*tlb
, unsigned long *table
,
1017 unsigned long vmaddr
)
1019 struct mm_struct
*mm
;
1021 unsigned int bit
, mask
;
1024 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1025 if (mm_alloc_pgste(mm
)) {
1026 gmap_unlink(mm
, table
, vmaddr
);
1027 table
= (unsigned long *) (__pa(table
) | 3);
1028 tlb_remove_table(tlb
, table
);
1031 bit
= (__pa(table
) & ~PAGE_MASK
) / (PTRS_PER_PTE
*sizeof(pte_t
));
1032 spin_lock_bh(&mm
->context
.list_lock
);
1033 mask
= atomic_xor_bits(&page
->_mapcount
, 0x11U
<< bit
);
1035 list_add_tail(&page
->lru
, &mm
->context
.pgtable_list
);
1037 list_del(&page
->lru
);
1038 spin_unlock_bh(&mm
->context
.list_lock
);
1039 table
= (unsigned long *) (__pa(table
) | (1U << bit
));
1040 tlb_remove_table(tlb
, table
);
1043 static void __tlb_remove_table(void *_table
)
1045 unsigned int mask
= (unsigned long) _table
& 3;
1046 void *table
= (void *)((unsigned long) _table
^ mask
);
1047 struct page
*page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1050 case 0: /* pmd or pud */
1051 free_pages((unsigned long) table
, 2);
1053 case 1: /* lower 2K of a 4K page table */
1054 case 2: /* higher 2K of a 4K page table */
1055 if (atomic_xor_bits(&page
->_mapcount
, mask
<< 4) != 0)
1058 case 3: /* 4K page table with pgstes */
1059 pgtable_page_dtor(page
);
1060 atomic_set(&page
->_mapcount
, -1);
1066 static void tlb_remove_table_smp_sync(void *arg
)
1068 /* Simply deliver the interrupt */
1071 static void tlb_remove_table_one(void *table
)
1074 * This isn't an RCU grace period and hence the page-tables cannot be
1075 * assumed to be actually RCU-freed.
1077 * It is however sufficient for software page-table walkers that rely
1078 * on IRQ disabling. See the comment near struct mmu_table_batch.
1080 smp_call_function(tlb_remove_table_smp_sync
, NULL
, 1);
1081 __tlb_remove_table(table
);
1084 static void tlb_remove_table_rcu(struct rcu_head
*head
)
1086 struct mmu_table_batch
*batch
;
1089 batch
= container_of(head
, struct mmu_table_batch
, rcu
);
1091 for (i
= 0; i
< batch
->nr
; i
++)
1092 __tlb_remove_table(batch
->tables
[i
]);
1094 free_page((unsigned long)batch
);
1097 void tlb_table_flush(struct mmu_gather
*tlb
)
1099 struct mmu_table_batch
**batch
= &tlb
->batch
;
1102 call_rcu_sched(&(*batch
)->rcu
, tlb_remove_table_rcu
);
1107 void tlb_remove_table(struct mmu_gather
*tlb
, void *table
)
1109 struct mmu_table_batch
**batch
= &tlb
->batch
;
1111 tlb
->mm
->context
.flush_mm
= 1;
1112 if (*batch
== NULL
) {
1113 *batch
= (struct mmu_table_batch
*)
1114 __get_free_page(GFP_NOWAIT
| __GFP_NOWARN
);
1115 if (*batch
== NULL
) {
1116 __tlb_flush_mm_lazy(tlb
->mm
);
1117 tlb_remove_table_one(table
);
1122 (*batch
)->tables
[(*batch
)->nr
++] = table
;
1123 if ((*batch
)->nr
== MAX_TABLE_BATCH
)
1127 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1128 static inline void thp_split_vma(struct vm_area_struct
*vma
)
1132 for (addr
= vma
->vm_start
; addr
< vma
->vm_end
; addr
+= PAGE_SIZE
)
1133 follow_page(vma
, addr
, FOLL_SPLIT
);
1136 static inline void thp_split_mm(struct mm_struct
*mm
)
1138 struct vm_area_struct
*vma
;
1140 for (vma
= mm
->mmap
; vma
!= NULL
; vma
= vma
->vm_next
) {
1142 vma
->vm_flags
&= ~VM_HUGEPAGE
;
1143 vma
->vm_flags
|= VM_NOHUGEPAGE
;
1145 mm
->def_flags
|= VM_NOHUGEPAGE
;
1148 static inline void thp_split_mm(struct mm_struct
*mm
)
1151 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1154 * switch on pgstes for its userspace process (for kvm)
1156 int s390_enable_sie(void)
1158 struct mm_struct
*mm
= current
->mm
;
1160 /* Do we have pgstes? if yes, we are done */
1161 if (mm_has_pgste(mm
))
1163 /* Fail if the page tables are 2K */
1164 if (!mm_alloc_pgste(mm
))
1166 down_write(&mm
->mmap_sem
);
1167 mm
->context
.has_pgste
= 1;
1168 /* split thp mappings and disable thp for future mappings */
1170 up_write(&mm
->mmap_sem
);
1173 EXPORT_SYMBOL_GPL(s390_enable_sie
);
1176 * Enable storage key handling from now on and initialize the storage
1177 * keys with the default key.
1179 static int __s390_enable_skey(pte_t
*pte
, unsigned long addr
,
1180 unsigned long next
, struct mm_walk
*walk
)
1185 pgste
= pgste_get_lock(pte
);
1187 * Remove all zero page mappings,
1188 * after establishing a policy to forbid zero page mappings
1189 * following faults for that page will get fresh anonymous pages
1191 if (is_zero_pfn(pte_pfn(*pte
))) {
1192 ptep_flush_direct(walk
->mm
, addr
, pte
);
1193 pte_val(*pte
) = _PAGE_INVALID
;
1195 /* Clear storage key */
1196 pgste_val(pgste
) &= ~(PGSTE_ACC_BITS
| PGSTE_FP_BIT
|
1197 PGSTE_GR_BIT
| PGSTE_GC_BIT
);
1198 ptev
= pte_val(*pte
);
1199 if (!(ptev
& _PAGE_INVALID
) && (ptev
& _PAGE_WRITE
))
1200 page_set_storage_key(ptev
& PAGE_MASK
, PAGE_DEFAULT_KEY
, 1);
1201 pgste_set_unlock(pte
, pgste
);
1205 int s390_enable_skey(void)
1207 struct mm_walk walk
= { .pte_entry
= __s390_enable_skey
};
1208 struct mm_struct
*mm
= current
->mm
;
1209 struct vm_area_struct
*vma
;
1212 down_write(&mm
->mmap_sem
);
1213 if (mm_use_skey(mm
))
1216 mm
->context
.use_skey
= 1;
1217 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
1218 if (ksm_madvise(vma
, vma
->vm_start
, vma
->vm_end
,
1219 MADV_UNMERGEABLE
, &vma
->vm_flags
)) {
1220 mm
->context
.use_skey
= 0;
1225 mm
->def_flags
&= ~VM_MERGEABLE
;
1228 walk_page_range(0, TASK_SIZE
, &walk
);
1231 up_write(&mm
->mmap_sem
);
1234 EXPORT_SYMBOL_GPL(s390_enable_skey
);
1237 * Reset CMMA state, make all pages stable again.
1239 static int __s390_reset_cmma(pte_t
*pte
, unsigned long addr
,
1240 unsigned long next
, struct mm_walk
*walk
)
1244 pgste
= pgste_get_lock(pte
);
1245 pgste_val(pgste
) &= ~_PGSTE_GPS_USAGE_MASK
;
1246 pgste_set_unlock(pte
, pgste
);
1250 void s390_reset_cmma(struct mm_struct
*mm
)
1252 struct mm_walk walk
= { .pte_entry
= __s390_reset_cmma
};
1254 down_write(&mm
->mmap_sem
);
1256 walk_page_range(0, TASK_SIZE
, &walk
);
1257 up_write(&mm
->mmap_sem
);
1259 EXPORT_SYMBOL_GPL(s390_reset_cmma
);
1262 * Test and reset if a guest page is dirty
1264 bool gmap_test_and_clear_dirty(unsigned long address
, struct gmap
*gmap
)
1270 pte
= get_locked_pte(gmap
->mm
, address
, &ptl
);
1274 if (ptep_test_and_clear_user_dirty(gmap
->mm
, address
, pte
))
1280 EXPORT_SYMBOL_GPL(gmap_test_and_clear_dirty
);
1282 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1283 int pmdp_clear_flush_young(struct vm_area_struct
*vma
, unsigned long address
,
1286 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1287 /* No need to flush TLB
1288 * On s390 reference bits are in storage key and never in TLB */
1289 return pmdp_test_and_clear_young(vma
, address
, pmdp
);
1292 int pmdp_set_access_flags(struct vm_area_struct
*vma
,
1293 unsigned long address
, pmd_t
*pmdp
,
1294 pmd_t entry
, int dirty
)
1296 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1298 entry
= pmd_mkyoung(entry
);
1300 entry
= pmd_mkdirty(entry
);
1301 if (pmd_same(*pmdp
, entry
))
1303 pmdp_invalidate(vma
, address
, pmdp
);
1304 set_pmd_at(vma
->vm_mm
, address
, pmdp
, entry
);
1308 static void pmdp_splitting_flush_sync(void *arg
)
1310 /* Simply deliver the interrupt */
1313 void pmdp_splitting_flush(struct vm_area_struct
*vma
, unsigned long address
,
1316 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1317 if (!test_and_set_bit(_SEGMENT_ENTRY_SPLIT_BIT
,
1318 (unsigned long *) pmdp
)) {
1319 /* need to serialize against gup-fast (IRQ disabled) */
1320 smp_call_function(pmdp_splitting_flush_sync
, NULL
, 1);
1324 void pgtable_trans_huge_deposit(struct mm_struct
*mm
, pmd_t
*pmdp
,
1327 struct list_head
*lh
= (struct list_head
*) pgtable
;
1329 assert_spin_locked(pmd_lockptr(mm
, pmdp
));
1332 if (!pmd_huge_pte(mm
, pmdp
))
1335 list_add(lh
, (struct list_head
*) pmd_huge_pte(mm
, pmdp
));
1336 pmd_huge_pte(mm
, pmdp
) = pgtable
;
1339 pgtable_t
pgtable_trans_huge_withdraw(struct mm_struct
*mm
, pmd_t
*pmdp
)
1341 struct list_head
*lh
;
1345 assert_spin_locked(pmd_lockptr(mm
, pmdp
));
1348 pgtable
= pmd_huge_pte(mm
, pmdp
);
1349 lh
= (struct list_head
*) pgtable
;
1351 pmd_huge_pte(mm
, pmdp
) = NULL
;
1353 pmd_huge_pte(mm
, pmdp
) = (pgtable_t
) lh
->next
;
1356 ptep
= (pte_t
*) pgtable
;
1357 pte_val(*ptep
) = _PAGE_INVALID
;
1359 pte_val(*ptep
) = _PAGE_INVALID
;
1362 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */