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/highmem.h>
14 #include <linux/pagemap.h>
15 #include <linux/spinlock.h>
16 #include <linux/module.h>
17 #include <linux/quicklist.h>
18 #include <linux/rcupdate.h>
19 #include <linux/slab.h>
20 #include <linux/swapops.h>
21 #include <linux/sysctl.h>
22 #include <linux/ksm.h>
23 #include <linux/mman.h>
25 #include <asm/pgtable.h>
26 #include <asm/pgalloc.h>
28 #include <asm/tlbflush.h>
29 #include <asm/mmu_context.h>
32 #define FRAG_MASK 0x03
36 unsigned long *crst_table_alloc(struct mm_struct
*mm
)
38 struct page
*page
= alloc_pages(GFP_KERNEL
, ALLOC_ORDER
);
42 return (unsigned long *) page_to_phys(page
);
45 void crst_table_free(struct mm_struct
*mm
, unsigned long *table
)
47 free_pages((unsigned long) table
, ALLOC_ORDER
);
50 static void __crst_table_upgrade(void *arg
)
52 struct mm_struct
*mm
= arg
;
54 if (current
->active_mm
== mm
) {
61 int crst_table_upgrade(struct mm_struct
*mm
, unsigned long limit
)
63 unsigned long *table
, *pgd
;
67 BUG_ON(limit
> (1UL << 53));
70 table
= crst_table_alloc(mm
);
73 spin_lock_bh(&mm
->page_table_lock
);
74 if (mm
->context
.asce_limit
< limit
) {
75 pgd
= (unsigned long *) mm
->pgd
;
76 if (mm
->context
.asce_limit
<= (1UL << 31)) {
77 entry
= _REGION3_ENTRY_EMPTY
;
78 mm
->context
.asce_limit
= 1UL << 42;
79 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
83 entry
= _REGION2_ENTRY_EMPTY
;
84 mm
->context
.asce_limit
= 1UL << 53;
85 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
89 crst_table_init(table
, entry
);
90 pgd_populate(mm
, (pgd_t
*) table
, (pud_t
*) pgd
);
91 mm
->pgd
= (pgd_t
*) table
;
92 mm
->task_size
= mm
->context
.asce_limit
;
96 spin_unlock_bh(&mm
->page_table_lock
);
98 crst_table_free(mm
, table
);
99 if (mm
->context
.asce_limit
< limit
)
102 on_each_cpu(__crst_table_upgrade
, mm
, 0);
106 void crst_table_downgrade(struct mm_struct
*mm
, unsigned long limit
)
110 if (current
->active_mm
== mm
) {
114 while (mm
->context
.asce_limit
> limit
) {
116 switch (pgd_val(*pgd
) & _REGION_ENTRY_TYPE_MASK
) {
117 case _REGION_ENTRY_TYPE_R2
:
118 mm
->context
.asce_limit
= 1UL << 42;
119 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
123 case _REGION_ENTRY_TYPE_R3
:
124 mm
->context
.asce_limit
= 1UL << 31;
125 mm
->context
.asce_bits
= _ASCE_TABLE_LENGTH
|
132 mm
->pgd
= (pgd_t
*) (pgd_val(*pgd
) & _REGION_ENTRY_ORIGIN
);
133 mm
->task_size
= mm
->context
.asce_limit
;
134 crst_table_free(mm
, (unsigned long *) pgd
);
136 if (current
->active_mm
== mm
)
143 * gmap_alloc - allocate a guest address space
144 * @mm: pointer to the parent mm_struct
145 * @limit: maximum size of the gmap address space
147 * Returns a guest address space structure.
149 struct gmap
*gmap_alloc(struct mm_struct
*mm
, unsigned long limit
)
153 unsigned long *table
;
154 unsigned long etype
, atype
;
156 if (limit
< (1UL << 31)) {
157 limit
= (1UL << 31) - 1;
158 atype
= _ASCE_TYPE_SEGMENT
;
159 etype
= _SEGMENT_ENTRY_EMPTY
;
160 } else if (limit
< (1UL << 42)) {
161 limit
= (1UL << 42) - 1;
162 atype
= _ASCE_TYPE_REGION3
;
163 etype
= _REGION3_ENTRY_EMPTY
;
164 } else if (limit
< (1UL << 53)) {
165 limit
= (1UL << 53) - 1;
166 atype
= _ASCE_TYPE_REGION2
;
167 etype
= _REGION2_ENTRY_EMPTY
;
170 atype
= _ASCE_TYPE_REGION1
;
171 etype
= _REGION1_ENTRY_EMPTY
;
173 gmap
= kzalloc(sizeof(struct gmap
), GFP_KERNEL
);
176 INIT_LIST_HEAD(&gmap
->crst_list
);
177 INIT_RADIX_TREE(&gmap
->guest_to_host
, GFP_KERNEL
);
178 INIT_RADIX_TREE(&gmap
->host_to_guest
, GFP_ATOMIC
);
179 spin_lock_init(&gmap
->guest_table_lock
);
181 page
= alloc_pages(GFP_KERNEL
, ALLOC_ORDER
);
185 list_add(&page
->lru
, &gmap
->crst_list
);
186 table
= (unsigned long *) page_to_phys(page
);
187 crst_table_init(table
, etype
);
189 gmap
->asce
= atype
| _ASCE_TABLE_LENGTH
|
190 _ASCE_USER_BITS
| __pa(table
);
191 gmap
->asce_end
= limit
;
192 down_write(&mm
->mmap_sem
);
193 list_add(&gmap
->list
, &mm
->context
.gmap_list
);
194 up_write(&mm
->mmap_sem
);
202 EXPORT_SYMBOL_GPL(gmap_alloc
);
204 static void gmap_flush_tlb(struct gmap
*gmap
)
206 if (MACHINE_HAS_IDTE
)
207 __tlb_flush_asce(gmap
->mm
, gmap
->asce
);
209 __tlb_flush_global();
212 static void gmap_radix_tree_free(struct radix_tree_root
*root
)
214 struct radix_tree_iter iter
;
215 unsigned long indices
[16];
220 /* A radix tree is freed by deleting all of its entries */
224 radix_tree_for_each_slot(slot
, root
, &iter
, index
) {
225 indices
[nr
] = iter
.index
;
229 for (i
= 0; i
< nr
; i
++) {
231 radix_tree_delete(root
, index
);
237 * gmap_free - free a guest address space
238 * @gmap: pointer to the guest address space structure
240 void gmap_free(struct gmap
*gmap
)
242 struct page
*page
, *next
;
245 if (MACHINE_HAS_IDTE
)
246 __tlb_flush_asce(gmap
->mm
, gmap
->asce
);
248 __tlb_flush_global();
250 /* Free all segment & region tables. */
251 list_for_each_entry_safe(page
, next
, &gmap
->crst_list
, lru
)
252 __free_pages(page
, ALLOC_ORDER
);
253 gmap_radix_tree_free(&gmap
->guest_to_host
);
254 gmap_radix_tree_free(&gmap
->host_to_guest
);
255 down_write(&gmap
->mm
->mmap_sem
);
256 list_del(&gmap
->list
);
257 up_write(&gmap
->mm
->mmap_sem
);
260 EXPORT_SYMBOL_GPL(gmap_free
);
263 * gmap_enable - switch primary space to the guest address space
264 * @gmap: pointer to the guest address space structure
266 void gmap_enable(struct gmap
*gmap
)
268 S390_lowcore
.gmap
= (unsigned long) gmap
;
270 EXPORT_SYMBOL_GPL(gmap_enable
);
273 * gmap_disable - switch back to the standard primary address space
274 * @gmap: pointer to the guest address space structure
276 void gmap_disable(struct gmap
*gmap
)
278 S390_lowcore
.gmap
= 0UL;
280 EXPORT_SYMBOL_GPL(gmap_disable
);
283 * gmap_alloc_table is assumed to be called with mmap_sem held
285 static int gmap_alloc_table(struct gmap
*gmap
, unsigned long *table
,
286 unsigned long init
, unsigned long gaddr
)
291 /* since we dont free the gmap table until gmap_free we can unlock */
292 page
= alloc_pages(GFP_KERNEL
, ALLOC_ORDER
);
295 new = (unsigned long *) page_to_phys(page
);
296 crst_table_init(new, init
);
297 spin_lock(&gmap
->mm
->page_table_lock
);
298 if (*table
& _REGION_ENTRY_INVALID
) {
299 list_add(&page
->lru
, &gmap
->crst_list
);
300 *table
= (unsigned long) new | _REGION_ENTRY_LENGTH
|
301 (*table
& _REGION_ENTRY_TYPE_MASK
);
305 spin_unlock(&gmap
->mm
->page_table_lock
);
307 __free_pages(page
, ALLOC_ORDER
);
312 * __gmap_segment_gaddr - find virtual address from segment pointer
313 * @entry: pointer to a segment table entry in the guest address space
315 * Returns the virtual address in the guest address space for the segment
317 static unsigned long __gmap_segment_gaddr(unsigned long *entry
)
320 unsigned long offset
, mask
;
322 offset
= (unsigned long) entry
/ sizeof(unsigned long);
323 offset
= (offset
& (PTRS_PER_PMD
- 1)) * PMD_SIZE
;
324 mask
= ~(PTRS_PER_PMD
* sizeof(pmd_t
) - 1);
325 page
= virt_to_page((void *)((unsigned long) entry
& mask
));
326 return page
->index
+ offset
;
330 * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
331 * @gmap: pointer to the guest address space structure
332 * @vmaddr: address in the host process address space
334 * Returns 1 if a TLB flush is required
336 static int __gmap_unlink_by_vmaddr(struct gmap
*gmap
, unsigned long vmaddr
)
338 unsigned long *entry
;
341 spin_lock(&gmap
->guest_table_lock
);
342 entry
= radix_tree_delete(&gmap
->host_to_guest
, vmaddr
>> PMD_SHIFT
);
344 flush
= (*entry
!= _SEGMENT_ENTRY_INVALID
);
345 *entry
= _SEGMENT_ENTRY_INVALID
;
347 spin_unlock(&gmap
->guest_table_lock
);
352 * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
353 * @gmap: pointer to the guest address space structure
354 * @gaddr: address in the guest address space
356 * Returns 1 if a TLB flush is required
358 static int __gmap_unmap_by_gaddr(struct gmap
*gmap
, unsigned long gaddr
)
360 unsigned long vmaddr
;
362 vmaddr
= (unsigned long) radix_tree_delete(&gmap
->guest_to_host
,
364 return vmaddr
? __gmap_unlink_by_vmaddr(gmap
, vmaddr
) : 0;
368 * gmap_unmap_segment - unmap segment from the guest address space
369 * @gmap: pointer to the guest address space structure
370 * @to: address in the guest address space
371 * @len: length of the memory area to unmap
373 * Returns 0 if the unmap succeeded, -EINVAL if not.
375 int gmap_unmap_segment(struct gmap
*gmap
, unsigned long to
, unsigned long len
)
380 if ((to
| len
) & (PMD_SIZE
- 1))
382 if (len
== 0 || to
+ len
< to
)
386 down_write(&gmap
->mm
->mmap_sem
);
387 for (off
= 0; off
< len
; off
+= PMD_SIZE
)
388 flush
|= __gmap_unmap_by_gaddr(gmap
, to
+ off
);
389 up_write(&gmap
->mm
->mmap_sem
);
391 gmap_flush_tlb(gmap
);
394 EXPORT_SYMBOL_GPL(gmap_unmap_segment
);
397 * gmap_mmap_segment - map a segment to the guest address space
398 * @gmap: pointer to the guest address space structure
399 * @from: source address in the parent address space
400 * @to: target address in the guest address space
401 * @len: length of the memory area to map
403 * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
405 int gmap_map_segment(struct gmap
*gmap
, unsigned long from
,
406 unsigned long to
, unsigned long len
)
411 if ((from
| to
| len
) & (PMD_SIZE
- 1))
413 if (len
== 0 || from
+ len
< from
|| to
+ len
< to
||
414 from
+ len
> TASK_MAX_SIZE
|| to
+ len
> gmap
->asce_end
)
418 down_write(&gmap
->mm
->mmap_sem
);
419 for (off
= 0; off
< len
; off
+= PMD_SIZE
) {
420 /* Remove old translation */
421 flush
|= __gmap_unmap_by_gaddr(gmap
, to
+ off
);
422 /* Store new translation */
423 if (radix_tree_insert(&gmap
->guest_to_host
,
424 (to
+ off
) >> PMD_SHIFT
,
425 (void *) from
+ off
))
428 up_write(&gmap
->mm
->mmap_sem
);
430 gmap_flush_tlb(gmap
);
433 gmap_unmap_segment(gmap
, to
, len
);
436 EXPORT_SYMBOL_GPL(gmap_map_segment
);
439 * __gmap_translate - translate a guest address to a user space address
440 * @gmap: pointer to guest mapping meta data structure
441 * @gaddr: guest address
443 * Returns user space address which corresponds to the guest address or
444 * -EFAULT if no such mapping exists.
445 * This function does not establish potentially missing page table entries.
446 * The mmap_sem of the mm that belongs to the address space must be held
447 * when this function gets called.
449 unsigned long __gmap_translate(struct gmap
*gmap
, unsigned long gaddr
)
451 unsigned long vmaddr
;
453 vmaddr
= (unsigned long)
454 radix_tree_lookup(&gmap
->guest_to_host
, gaddr
>> PMD_SHIFT
);
455 return vmaddr
? (vmaddr
| (gaddr
& ~PMD_MASK
)) : -EFAULT
;
457 EXPORT_SYMBOL_GPL(__gmap_translate
);
460 * gmap_translate - translate a guest address to a user space address
461 * @gmap: pointer to guest mapping meta data structure
462 * @gaddr: guest address
464 * Returns user space address which corresponds to the guest address or
465 * -EFAULT if no such mapping exists.
466 * This function does not establish potentially missing page table entries.
468 unsigned long gmap_translate(struct gmap
*gmap
, unsigned long gaddr
)
472 down_read(&gmap
->mm
->mmap_sem
);
473 rc
= __gmap_translate(gmap
, gaddr
);
474 up_read(&gmap
->mm
->mmap_sem
);
477 EXPORT_SYMBOL_GPL(gmap_translate
);
480 * gmap_unlink - disconnect a page table from the gmap shadow tables
481 * @gmap: pointer to guest mapping meta data structure
482 * @table: pointer to the host page table
483 * @vmaddr: vm address associated with the host page table
485 static void gmap_unlink(struct mm_struct
*mm
, unsigned long *table
,
486 unsigned long vmaddr
)
491 list_for_each_entry(gmap
, &mm
->context
.gmap_list
, list
) {
492 flush
= __gmap_unlink_by_vmaddr(gmap
, vmaddr
);
494 gmap_flush_tlb(gmap
);
499 * gmap_link - set up shadow page tables to connect a host to a guest address
500 * @gmap: pointer to guest mapping meta data structure
501 * @gaddr: guest address
502 * @vmaddr: vm address
504 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
505 * if the vm address is already mapped to a different guest segment.
506 * The mmap_sem of the mm that belongs to the address space must be held
507 * when this function gets called.
509 int __gmap_link(struct gmap
*gmap
, unsigned long gaddr
, unsigned long vmaddr
)
511 struct mm_struct
*mm
;
512 unsigned long *table
;
519 /* Create higher level tables in the gmap page table */
521 if ((gmap
->asce
& _ASCE_TYPE_MASK
) >= _ASCE_TYPE_REGION1
) {
522 table
+= (gaddr
>> 53) & 0x7ff;
523 if ((*table
& _REGION_ENTRY_INVALID
) &&
524 gmap_alloc_table(gmap
, table
, _REGION2_ENTRY_EMPTY
,
525 gaddr
& 0xffe0000000000000UL
))
527 table
= (unsigned long *)(*table
& _REGION_ENTRY_ORIGIN
);
529 if ((gmap
->asce
& _ASCE_TYPE_MASK
) >= _ASCE_TYPE_REGION2
) {
530 table
+= (gaddr
>> 42) & 0x7ff;
531 if ((*table
& _REGION_ENTRY_INVALID
) &&
532 gmap_alloc_table(gmap
, table
, _REGION3_ENTRY_EMPTY
,
533 gaddr
& 0xfffffc0000000000UL
))
535 table
= (unsigned long *)(*table
& _REGION_ENTRY_ORIGIN
);
537 if ((gmap
->asce
& _ASCE_TYPE_MASK
) >= _ASCE_TYPE_REGION3
) {
538 table
+= (gaddr
>> 31) & 0x7ff;
539 if ((*table
& _REGION_ENTRY_INVALID
) &&
540 gmap_alloc_table(gmap
, table
, _SEGMENT_ENTRY_EMPTY
,
541 gaddr
& 0xffffffff80000000UL
))
543 table
= (unsigned long *)(*table
& _REGION_ENTRY_ORIGIN
);
545 table
+= (gaddr
>> 20) & 0x7ff;
546 /* Walk the parent mm page table */
548 pgd
= pgd_offset(mm
, vmaddr
);
549 VM_BUG_ON(pgd_none(*pgd
));
550 pud
= pud_offset(pgd
, vmaddr
);
551 VM_BUG_ON(pud_none(*pud
));
552 pmd
= pmd_offset(pud
, vmaddr
);
553 VM_BUG_ON(pmd_none(*pmd
));
554 /* large pmds cannot yet be handled */
557 /* Link gmap segment table entry location to page table. */
558 rc
= radix_tree_preload(GFP_KERNEL
);
561 ptl
= pmd_lock(mm
, pmd
);
562 spin_lock(&gmap
->guest_table_lock
);
563 if (*table
== _SEGMENT_ENTRY_INVALID
) {
564 rc
= radix_tree_insert(&gmap
->host_to_guest
,
565 vmaddr
>> PMD_SHIFT
, table
);
567 *table
= pmd_val(*pmd
);
570 spin_unlock(&gmap
->guest_table_lock
);
572 radix_tree_preload_end();
577 * gmap_fault - resolve a fault on a guest address
578 * @gmap: pointer to guest mapping meta data structure
579 * @gaddr: guest address
580 * @fault_flags: flags to pass down to handle_mm_fault()
582 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
583 * if the vm address is already mapped to a different guest segment.
585 int gmap_fault(struct gmap
*gmap
, unsigned long gaddr
,
586 unsigned int fault_flags
)
588 unsigned long vmaddr
;
591 down_read(&gmap
->mm
->mmap_sem
);
592 vmaddr
= __gmap_translate(gmap
, gaddr
);
593 if (IS_ERR_VALUE(vmaddr
)) {
597 if (fixup_user_fault(current
, gmap
->mm
, vmaddr
, fault_flags
)) {
601 rc
= __gmap_link(gmap
, gaddr
, vmaddr
);
603 up_read(&gmap
->mm
->mmap_sem
);
606 EXPORT_SYMBOL_GPL(gmap_fault
);
608 static void gmap_zap_swap_entry(swp_entry_t entry
, struct mm_struct
*mm
)
610 if (!non_swap_entry(entry
))
611 dec_mm_counter(mm
, MM_SWAPENTS
);
612 else if (is_migration_entry(entry
)) {
613 struct page
*page
= migration_entry_to_page(entry
);
616 dec_mm_counter(mm
, MM_ANONPAGES
);
618 dec_mm_counter(mm
, MM_FILEPAGES
);
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
)
731 if ((gaddr
& ~PAGE_MASK
) || (len
& ~PAGE_MASK
))
733 down_read(&gmap
->mm
->mmap_sem
);
735 /* Convert gmap address and connect the page tables */
736 addr
= __gmap_translate(gmap
, gaddr
);
737 if (IS_ERR_VALUE(addr
)) {
741 /* Get the page mapped */
742 if (fixup_user_fault(current
, gmap
->mm
, addr
, FAULT_FLAG_WRITE
)) {
746 rc
= __gmap_link(gmap
, gaddr
, addr
);
749 /* Walk the process page table, lock and get pte pointer */
750 ptep
= get_locked_pte(gmap
->mm
, addr
, &ptl
);
752 /* Set notification bit in the pgste of the pte */
754 if ((pte_val(entry
) & (_PAGE_INVALID
| _PAGE_PROTECT
)) == 0) {
755 pgste
= pgste_get_lock(ptep
);
756 pgste_val(pgste
) |= PGSTE_IN_BIT
;
757 pgste_set_unlock(ptep
, pgste
);
761 pte_unmap_unlock(ptep
, ptl
);
763 up_read(&gmap
->mm
->mmap_sem
);
766 EXPORT_SYMBOL_GPL(gmap_ipte_notify
);
769 * gmap_do_ipte_notify - call all invalidation callbacks for a specific pte.
770 * @mm: pointer to the process mm_struct
771 * @addr: virtual address in the process address space
772 * @pte: pointer to the page table entry
774 * This function is assumed to be called with the page table lock held
775 * for the pte to notify.
777 void gmap_do_ipte_notify(struct mm_struct
*mm
, unsigned long vmaddr
, pte_t
*pte
)
779 unsigned long offset
, gaddr
;
780 unsigned long *table
;
781 struct gmap_notifier
*nb
;
784 offset
= ((unsigned long) pte
) & (255 * sizeof(pte_t
));
785 offset
= offset
* (4096 / sizeof(pte_t
));
786 spin_lock(&gmap_notifier_lock
);
787 list_for_each_entry(gmap
, &mm
->context
.gmap_list
, list
) {
788 table
= radix_tree_lookup(&gmap
->host_to_guest
,
789 vmaddr
>> PMD_SHIFT
);
792 gaddr
= __gmap_segment_gaddr(table
) + offset
;
793 list_for_each_entry(nb
, &gmap_notifier_list
, list
)
794 nb
->notifier_call(gmap
, gaddr
);
796 spin_unlock(&gmap_notifier_lock
);
798 EXPORT_SYMBOL_GPL(gmap_do_ipte_notify
);
800 static inline int page_table_with_pgste(struct page
*page
)
802 return atomic_read(&page
->_mapcount
) == 0;
805 static inline unsigned long *page_table_alloc_pgste(struct mm_struct
*mm
)
808 unsigned long *table
;
810 page
= alloc_page(GFP_KERNEL
|__GFP_REPEAT
);
813 if (!pgtable_page_ctor(page
)) {
817 atomic_set(&page
->_mapcount
, 0);
818 table
= (unsigned long *) page_to_phys(page
);
819 clear_table(table
, _PAGE_INVALID
, PAGE_SIZE
/2);
820 clear_table(table
+ PTRS_PER_PTE
, 0, PAGE_SIZE
/2);
824 static inline void page_table_free_pgste(unsigned long *table
)
828 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
829 pgtable_page_dtor(page
);
830 atomic_set(&page
->_mapcount
, -1);
834 int set_guest_storage_key(struct mm_struct
*mm
, unsigned long addr
,
835 unsigned long key
, bool nq
)
841 down_read(&mm
->mmap_sem
);
843 ptep
= get_locked_pte(mm
, addr
, &ptl
);
844 if (unlikely(!ptep
)) {
845 up_read(&mm
->mmap_sem
);
848 if (!(pte_val(*ptep
) & _PAGE_INVALID
) &&
849 (pte_val(*ptep
) & _PAGE_PROTECT
)) {
850 pte_unmap_unlock(ptep
, ptl
);
851 if (fixup_user_fault(current
, mm
, addr
, FAULT_FLAG_WRITE
)) {
852 up_read(&mm
->mmap_sem
);
858 new = old
= pgste_get_lock(ptep
);
859 pgste_val(new) &= ~(PGSTE_GR_BIT
| PGSTE_GC_BIT
|
860 PGSTE_ACC_BITS
| PGSTE_FP_BIT
);
861 pgste_val(new) |= (key
& (_PAGE_CHANGED
| _PAGE_REFERENCED
)) << 48;
862 pgste_val(new) |= (key
& (_PAGE_ACC_BITS
| _PAGE_FP_BIT
)) << 56;
863 if (!(pte_val(*ptep
) & _PAGE_INVALID
)) {
864 unsigned long address
, bits
, skey
;
866 address
= pte_val(*ptep
) & PAGE_MASK
;
867 skey
= (unsigned long) page_get_storage_key(address
);
868 bits
= skey
& (_PAGE_CHANGED
| _PAGE_REFERENCED
);
869 skey
= key
& (_PAGE_ACC_BITS
| _PAGE_FP_BIT
);
870 /* Set storage key ACC and FP */
871 page_set_storage_key(address
, skey
, !nq
);
872 /* Merge host changed & referenced into pgste */
873 pgste_val(new) |= bits
<< 52;
875 /* changing the guest storage key is considered a change of the page */
876 if ((pgste_val(new) ^ pgste_val(old
)) &
877 (PGSTE_ACC_BITS
| PGSTE_FP_BIT
| PGSTE_GR_BIT
| PGSTE_GC_BIT
))
878 pgste_val(new) |= PGSTE_UC_BIT
;
880 pgste_set_unlock(ptep
, new);
881 pte_unmap_unlock(ptep
, ptl
);
882 up_read(&mm
->mmap_sem
);
885 EXPORT_SYMBOL(set_guest_storage_key
);
887 unsigned long get_guest_storage_key(struct mm_struct
*mm
, unsigned long addr
)
893 unsigned long key
= 0;
895 down_read(&mm
->mmap_sem
);
896 ptep
= get_locked_pte(mm
, addr
, &ptl
);
897 if (unlikely(!ptep
)) {
898 up_read(&mm
->mmap_sem
);
901 pgste
= pgste_get_lock(ptep
);
903 if (pte_val(*ptep
) & _PAGE_INVALID
) {
904 key
|= (pgste_val(pgste
) & PGSTE_ACC_BITS
) >> 56;
905 key
|= (pgste_val(pgste
) & PGSTE_FP_BIT
) >> 56;
906 key
|= (pgste_val(pgste
) & PGSTE_GR_BIT
) >> 48;
907 key
|= (pgste_val(pgste
) & PGSTE_GC_BIT
) >> 48;
909 physaddr
= pte_val(*ptep
) & PAGE_MASK
;
910 key
= page_get_storage_key(physaddr
);
912 /* Reflect guest's logical view, not physical */
913 if (pgste_val(pgste
) & PGSTE_GR_BIT
)
914 key
|= _PAGE_REFERENCED
;
915 if (pgste_val(pgste
) & PGSTE_GC_BIT
)
916 key
|= _PAGE_CHANGED
;
919 pgste_set_unlock(ptep
, pgste
);
920 pte_unmap_unlock(ptep
, ptl
);
921 up_read(&mm
->mmap_sem
);
924 EXPORT_SYMBOL(get_guest_storage_key
);
926 static int page_table_allocate_pgste_min
= 0;
927 static int page_table_allocate_pgste_max
= 1;
928 int page_table_allocate_pgste
= 0;
929 EXPORT_SYMBOL(page_table_allocate_pgste
);
931 static struct ctl_table page_table_sysctl
[] = {
933 .procname
= "allocate_pgste",
934 .data
= &page_table_allocate_pgste
,
935 .maxlen
= sizeof(int),
936 .mode
= S_IRUGO
| S_IWUSR
,
937 .proc_handler
= proc_dointvec
,
938 .extra1
= &page_table_allocate_pgste_min
,
939 .extra2
= &page_table_allocate_pgste_max
,
944 static struct ctl_table page_table_sysctl_dir
[] = {
949 .child
= page_table_sysctl
,
954 static int __init
page_table_register_sysctl(void)
956 return register_sysctl_table(page_table_sysctl_dir
) ? 0 : -ENOMEM
;
958 __initcall(page_table_register_sysctl
);
960 #else /* CONFIG_PGSTE */
962 static inline int page_table_with_pgste(struct page
*page
)
967 static inline unsigned long *page_table_alloc_pgste(struct mm_struct
*mm
)
972 static inline void page_table_free_pgste(unsigned long *table
)
976 static inline void gmap_unlink(struct mm_struct
*mm
, unsigned long *table
,
977 unsigned long vmaddr
)
981 #endif /* CONFIG_PGSTE */
983 static inline unsigned int atomic_xor_bits(atomic_t
*v
, unsigned int bits
)
985 unsigned int old
, new;
988 old
= atomic_read(v
);
990 } while (atomic_cmpxchg(v
, old
, new) != old
);
995 * page table entry allocation/free routines.
997 unsigned long *page_table_alloc(struct mm_struct
*mm
)
999 unsigned long *uninitialized_var(table
);
1000 struct page
*uninitialized_var(page
);
1001 unsigned int mask
, bit
;
1003 if (mm_alloc_pgste(mm
))
1004 return page_table_alloc_pgste(mm
);
1005 /* Allocate fragments of a 4K page as 1K/2K page table */
1006 spin_lock_bh(&mm
->context
.list_lock
);
1008 if (!list_empty(&mm
->context
.pgtable_list
)) {
1009 page
= list_first_entry(&mm
->context
.pgtable_list
,
1011 table
= (unsigned long *) page_to_phys(page
);
1012 mask
= atomic_read(&page
->_mapcount
);
1013 mask
= mask
| (mask
>> 4);
1015 if ((mask
& FRAG_MASK
) == FRAG_MASK
) {
1016 spin_unlock_bh(&mm
->context
.list_lock
);
1017 page
= alloc_page(GFP_KERNEL
|__GFP_REPEAT
);
1020 if (!pgtable_page_ctor(page
)) {
1024 atomic_set(&page
->_mapcount
, 1);
1025 table
= (unsigned long *) page_to_phys(page
);
1026 clear_table(table
, _PAGE_INVALID
, PAGE_SIZE
);
1027 spin_lock_bh(&mm
->context
.list_lock
);
1028 list_add(&page
->lru
, &mm
->context
.pgtable_list
);
1030 for (bit
= 1; mask
& bit
; bit
<<= 1)
1031 table
+= PTRS_PER_PTE
;
1032 mask
= atomic_xor_bits(&page
->_mapcount
, bit
);
1033 if ((mask
& FRAG_MASK
) == FRAG_MASK
)
1034 list_del(&page
->lru
);
1036 spin_unlock_bh(&mm
->context
.list_lock
);
1040 void page_table_free(struct mm_struct
*mm
, unsigned long *table
)
1043 unsigned int bit
, mask
;
1045 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1046 if (page_table_with_pgste(page
))
1047 return page_table_free_pgste(table
);
1048 /* Free 1K/2K page table fragment of a 4K page */
1049 bit
= 1 << ((__pa(table
) & ~PAGE_MASK
)/(PTRS_PER_PTE
*sizeof(pte_t
)));
1050 spin_lock_bh(&mm
->context
.list_lock
);
1051 if ((atomic_read(&page
->_mapcount
) & FRAG_MASK
) != FRAG_MASK
)
1052 list_del(&page
->lru
);
1053 mask
= atomic_xor_bits(&page
->_mapcount
, bit
);
1054 if (mask
& FRAG_MASK
)
1055 list_add(&page
->lru
, &mm
->context
.pgtable_list
);
1056 spin_unlock_bh(&mm
->context
.list_lock
);
1058 pgtable_page_dtor(page
);
1059 atomic_set(&page
->_mapcount
, -1);
1064 static void __page_table_free_rcu(void *table
, unsigned bit
)
1068 if (bit
== FRAG_MASK
)
1069 return page_table_free_pgste(table
);
1070 /* Free 1K/2K page table fragment of a 4K page */
1071 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1072 if (atomic_xor_bits(&page
->_mapcount
, bit
) == 0) {
1073 pgtable_page_dtor(page
);
1074 atomic_set(&page
->_mapcount
, -1);
1079 void page_table_free_rcu(struct mmu_gather
*tlb
, unsigned long *table
,
1080 unsigned long vmaddr
)
1082 struct mm_struct
*mm
;
1084 unsigned int bit
, mask
;
1087 page
= pfn_to_page(__pa(table
) >> PAGE_SHIFT
);
1088 if (page_table_with_pgste(page
)) {
1089 gmap_unlink(mm
, table
, vmaddr
);
1090 table
= (unsigned long *) (__pa(table
) | FRAG_MASK
);
1091 tlb_remove_table(tlb
, table
);
1094 bit
= 1 << ((__pa(table
) & ~PAGE_MASK
) / (PTRS_PER_PTE
*sizeof(pte_t
)));
1095 spin_lock_bh(&mm
->context
.list_lock
);
1096 if ((atomic_read(&page
->_mapcount
) & FRAG_MASK
) != FRAG_MASK
)
1097 list_del(&page
->lru
);
1098 mask
= atomic_xor_bits(&page
->_mapcount
, bit
| (bit
<< 4));
1099 if (mask
& FRAG_MASK
)
1100 list_add_tail(&page
->lru
, &mm
->context
.pgtable_list
);
1101 spin_unlock_bh(&mm
->context
.list_lock
);
1102 table
= (unsigned long *) (__pa(table
) | (bit
<< 4));
1103 tlb_remove_table(tlb
, table
);
1106 static void __tlb_remove_table(void *_table
)
1108 const unsigned long mask
= (FRAG_MASK
<< 4) | FRAG_MASK
;
1109 void *table
= (void *)((unsigned long) _table
& ~mask
);
1110 unsigned type
= (unsigned long) _table
& mask
;
1113 __page_table_free_rcu(table
, type
);
1115 free_pages((unsigned long) table
, ALLOC_ORDER
);
1118 static void tlb_remove_table_smp_sync(void *arg
)
1120 /* Simply deliver the interrupt */
1123 static void tlb_remove_table_one(void *table
)
1126 * This isn't an RCU grace period and hence the page-tables cannot be
1127 * assumed to be actually RCU-freed.
1129 * It is however sufficient for software page-table walkers that rely
1130 * on IRQ disabling. See the comment near struct mmu_table_batch.
1132 smp_call_function(tlb_remove_table_smp_sync
, NULL
, 1);
1133 __tlb_remove_table(table
);
1136 static void tlb_remove_table_rcu(struct rcu_head
*head
)
1138 struct mmu_table_batch
*batch
;
1141 batch
= container_of(head
, struct mmu_table_batch
, rcu
);
1143 for (i
= 0; i
< batch
->nr
; i
++)
1144 __tlb_remove_table(batch
->tables
[i
]);
1146 free_page((unsigned long)batch
);
1149 void tlb_table_flush(struct mmu_gather
*tlb
)
1151 struct mmu_table_batch
**batch
= &tlb
->batch
;
1154 call_rcu_sched(&(*batch
)->rcu
, tlb_remove_table_rcu
);
1159 void tlb_remove_table(struct mmu_gather
*tlb
, void *table
)
1161 struct mmu_table_batch
**batch
= &tlb
->batch
;
1163 tlb
->mm
->context
.flush_mm
= 1;
1164 if (*batch
== NULL
) {
1165 *batch
= (struct mmu_table_batch
*)
1166 __get_free_page(GFP_NOWAIT
| __GFP_NOWARN
);
1167 if (*batch
== NULL
) {
1168 __tlb_flush_mm_lazy(tlb
->mm
);
1169 tlb_remove_table_one(table
);
1174 (*batch
)->tables
[(*batch
)->nr
++] = table
;
1175 if ((*batch
)->nr
== MAX_TABLE_BATCH
)
1179 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1180 static inline void thp_split_vma(struct vm_area_struct
*vma
)
1184 for (addr
= vma
->vm_start
; addr
< vma
->vm_end
; addr
+= PAGE_SIZE
)
1185 follow_page(vma
, addr
, FOLL_SPLIT
);
1188 static inline void thp_split_mm(struct mm_struct
*mm
)
1190 struct vm_area_struct
*vma
;
1192 for (vma
= mm
->mmap
; vma
!= NULL
; vma
= vma
->vm_next
) {
1194 vma
->vm_flags
&= ~VM_HUGEPAGE
;
1195 vma
->vm_flags
|= VM_NOHUGEPAGE
;
1197 mm
->def_flags
|= VM_NOHUGEPAGE
;
1200 static inline void thp_split_mm(struct mm_struct
*mm
)
1203 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1206 * switch on pgstes for its userspace process (for kvm)
1208 int s390_enable_sie(void)
1210 struct mm_struct
*mm
= current
->mm
;
1212 /* Do we have pgstes? if yes, we are done */
1213 if (mm_has_pgste(mm
))
1215 /* Fail if the page tables are 2K */
1216 if (!mm_alloc_pgste(mm
))
1218 down_write(&mm
->mmap_sem
);
1219 mm
->context
.has_pgste
= 1;
1220 /* split thp mappings and disable thp for future mappings */
1222 up_write(&mm
->mmap_sem
);
1225 EXPORT_SYMBOL_GPL(s390_enable_sie
);
1228 * Enable storage key handling from now on and initialize the storage
1229 * keys with the default key.
1231 static int __s390_enable_skey(pte_t
*pte
, unsigned long addr
,
1232 unsigned long next
, struct mm_walk
*walk
)
1237 pgste
= pgste_get_lock(pte
);
1239 * Remove all zero page mappings,
1240 * after establishing a policy to forbid zero page mappings
1241 * following faults for that page will get fresh anonymous pages
1243 if (is_zero_pfn(pte_pfn(*pte
))) {
1244 ptep_flush_direct(walk
->mm
, addr
, pte
);
1245 pte_val(*pte
) = _PAGE_INVALID
;
1247 /* Clear storage key */
1248 pgste_val(pgste
) &= ~(PGSTE_ACC_BITS
| PGSTE_FP_BIT
|
1249 PGSTE_GR_BIT
| PGSTE_GC_BIT
);
1250 ptev
= pte_val(*pte
);
1251 if (!(ptev
& _PAGE_INVALID
) && (ptev
& _PAGE_WRITE
))
1252 page_set_storage_key(ptev
& PAGE_MASK
, PAGE_DEFAULT_KEY
, 1);
1253 pgste_set_unlock(pte
, pgste
);
1257 int s390_enable_skey(void)
1259 struct mm_walk walk
= { .pte_entry
= __s390_enable_skey
};
1260 struct mm_struct
*mm
= current
->mm
;
1261 struct vm_area_struct
*vma
;
1264 down_write(&mm
->mmap_sem
);
1265 if (mm_use_skey(mm
))
1268 mm
->context
.use_skey
= 1;
1269 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
1270 if (ksm_madvise(vma
, vma
->vm_start
, vma
->vm_end
,
1271 MADV_UNMERGEABLE
, &vma
->vm_flags
)) {
1272 mm
->context
.use_skey
= 0;
1277 mm
->def_flags
&= ~VM_MERGEABLE
;
1280 walk_page_range(0, TASK_SIZE
, &walk
);
1283 up_write(&mm
->mmap_sem
);
1286 EXPORT_SYMBOL_GPL(s390_enable_skey
);
1289 * Reset CMMA state, make all pages stable again.
1291 static int __s390_reset_cmma(pte_t
*pte
, unsigned long addr
,
1292 unsigned long next
, struct mm_walk
*walk
)
1296 pgste
= pgste_get_lock(pte
);
1297 pgste_val(pgste
) &= ~_PGSTE_GPS_USAGE_MASK
;
1298 pgste_set_unlock(pte
, pgste
);
1302 void s390_reset_cmma(struct mm_struct
*mm
)
1304 struct mm_walk walk
= { .pte_entry
= __s390_reset_cmma
};
1306 down_write(&mm
->mmap_sem
);
1308 walk_page_range(0, TASK_SIZE
, &walk
);
1309 up_write(&mm
->mmap_sem
);
1311 EXPORT_SYMBOL_GPL(s390_reset_cmma
);
1314 * Test and reset if a guest page is dirty
1316 bool gmap_test_and_clear_dirty(unsigned long address
, struct gmap
*gmap
)
1322 pte
= get_locked_pte(gmap
->mm
, address
, &ptl
);
1326 if (ptep_test_and_clear_user_dirty(gmap
->mm
, address
, pte
))
1332 EXPORT_SYMBOL_GPL(gmap_test_and_clear_dirty
);
1334 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1335 int pmdp_clear_flush_young(struct vm_area_struct
*vma
, unsigned long address
,
1338 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1339 /* No need to flush TLB
1340 * On s390 reference bits are in storage key and never in TLB */
1341 return pmdp_test_and_clear_young(vma
, address
, pmdp
);
1344 int pmdp_set_access_flags(struct vm_area_struct
*vma
,
1345 unsigned long address
, pmd_t
*pmdp
,
1346 pmd_t entry
, int dirty
)
1348 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1350 entry
= pmd_mkyoung(entry
);
1352 entry
= pmd_mkdirty(entry
);
1353 if (pmd_same(*pmdp
, entry
))
1355 pmdp_invalidate(vma
, address
, pmdp
);
1356 set_pmd_at(vma
->vm_mm
, address
, pmdp
, entry
);
1360 static void pmdp_splitting_flush_sync(void *arg
)
1362 /* Simply deliver the interrupt */
1365 void pmdp_splitting_flush(struct vm_area_struct
*vma
, unsigned long address
,
1368 VM_BUG_ON(address
& ~HPAGE_PMD_MASK
);
1369 if (!test_and_set_bit(_SEGMENT_ENTRY_SPLIT_BIT
,
1370 (unsigned long *) pmdp
)) {
1371 /* need to serialize against gup-fast (IRQ disabled) */
1372 smp_call_function(pmdp_splitting_flush_sync
, NULL
, 1);
1376 void pgtable_trans_huge_deposit(struct mm_struct
*mm
, pmd_t
*pmdp
,
1379 struct list_head
*lh
= (struct list_head
*) pgtable
;
1381 assert_spin_locked(pmd_lockptr(mm
, pmdp
));
1384 if (!pmd_huge_pte(mm
, pmdp
))
1387 list_add(lh
, (struct list_head
*) pmd_huge_pte(mm
, pmdp
));
1388 pmd_huge_pte(mm
, pmdp
) = pgtable
;
1391 pgtable_t
pgtable_trans_huge_withdraw(struct mm_struct
*mm
, pmd_t
*pmdp
)
1393 struct list_head
*lh
;
1397 assert_spin_locked(pmd_lockptr(mm
, pmdp
));
1400 pgtable
= pmd_huge_pte(mm
, pmdp
);
1401 lh
= (struct list_head
*) pgtable
;
1403 pmd_huge_pte(mm
, pmdp
) = NULL
;
1405 pmd_huge_pte(mm
, pmdp
) = (pgtable_t
) lh
->next
;
1408 ptep
= (pte_t
*) pgtable
;
1409 pte_val(*ptep
) = _PAGE_INVALID
;
1411 pte_val(*ptep
) = _PAGE_INVALID
;
1414 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */