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[S390] qdio: 2nd stage retry on SIGA-W busy conditions
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / s390 / mm / pgtable.c
CommitLineData
3610cce8 1/*
239a6425 2 * Copyright IBM Corp. 2007,2009
3610cce8
MS		 3 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
4 */
5
6#include <linux/sched.h>
7#include <linux/kernel.h>
8#include <linux/errno.h>
5a0e3ad6 9#include <linux/gfp.h>
3610cce8
MS		 10#include <linux/mm.h>
11#include <linux/swap.h>
12#include <linux/smp.h>
13#include <linux/highmem.h>
3610cce8
MS		 14#include <linux/pagemap.h>
15#include <linux/spinlock.h>
16#include <linux/module.h>
17#include <linux/quicklist.h>
80217147 18#include <linux/rcupdate.h>
e5992f2e 19#include <linux/slab.h>
3610cce8
MS		 20
21#include <asm/system.h>
22#include <asm/pgtable.h>
23#include <asm/pgalloc.h>
24#include <asm/tlb.h>
25#include <asm/tlbflush.h>
6252d702 26#include <asm/mmu_context.h>
3610cce8
MS		 27
28#ifndef CONFIG_64BIT
29#define ALLOC_ORDER 1
36409f63 30#define FRAG_MASK 0x0f
3610cce8
MS		 31#else
32#define ALLOC_ORDER 2
36409f63 33#define FRAG_MASK 0x03
3610cce8
MS		 34#endif
35
239a6425
HC		 36unsigned long VMALLOC_START = VMALLOC_END - VMALLOC_SIZE;
37EXPORT_SYMBOL(VMALLOC_START);
38
39static int __init parse_vmalloc(char *arg)
40{
41 if (!arg)
42 return -EINVAL;
43 VMALLOC_START = (VMALLOC_END - memparse(arg, &arg)) & PAGE_MASK;
44 return 0;
45}
46early_param("vmalloc", parse_vmalloc);
47
043d0708 48unsigned long *crst_table_alloc(struct mm_struct *mm)
3610cce8
MS		 49{
50 struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
51
52 if (!page)
53 return NULL;
3610cce8
MS		 54 return (unsigned long *) page_to_phys(page);
55}
56
80217147
MS		 57void crst_table_free(struct mm_struct *mm, unsigned long *table)
58{
043d0708 59 free_pages((unsigned long) table, ALLOC_ORDER);
80217147
MS		 60}
61
6252d702
MS		 62#ifdef CONFIG_64BIT
63int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
64{
65 unsigned long *table, *pgd;
66 unsigned long entry;
67
68 BUG_ON(limit > (1UL << 53));
69repeat:
043d0708 70 table = crst_table_alloc(mm);
6252d702
MS		 71 if (!table)
72 return -ENOMEM;
80217147 73 spin_lock_bh(&mm->page_table_lock);
6252d702
MS		 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 |
80 _ASCE_USER_BITS |
81 _ASCE_TYPE_REGION3;
82 } else {
83 entry = _REGION2_ENTRY_EMPTY;
84 mm->context.asce_limit = 1UL << 53;
85 mm->context.asce_bits = _ASCE_TABLE_LENGTH |
86 _ASCE_USER_BITS |
87 _ASCE_TYPE_REGION2;
88 }
89 crst_table_init(table, entry);
90 pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
91 mm->pgd = (pgd_t *) table;
f481bfaf 92 mm->task_size = mm->context.asce_limit;
6252d702
MS		 93 table = NULL;
94 }
80217147 95 spin_unlock_bh(&mm->page_table_lock);
6252d702
MS		 96 if (table)
97 crst_table_free(mm, table);
98 if (mm->context.asce_limit < limit)
99 goto repeat;
100 update_mm(mm, current);
101 return 0;
102}
103
104void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
105{
106 pgd_t *pgd;
107
108 if (mm->context.asce_limit <= limit)
109 return;
110 __tlb_flush_mm(mm);
111 while (mm->context.asce_limit > limit) {
112 pgd = mm->pgd;
113 switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
114 case _REGION_ENTRY_TYPE_R2:
115 mm->context.asce_limit = 1UL << 42;
116 mm->context.asce_bits = _ASCE_TABLE_LENGTH |
117 _ASCE_USER_BITS |
118 _ASCE_TYPE_REGION3;
119 break;
120 case _REGION_ENTRY_TYPE_R3:
121 mm->context.asce_limit = 1UL << 31;
122 mm->context.asce_bits = _ASCE_TABLE_LENGTH |
123 _ASCE_USER_BITS |
124 _ASCE_TYPE_SEGMENT;
125 break;
126 default:
127 BUG();
128 }
129 mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
f481bfaf 130 mm->task_size = mm->context.asce_limit;
6252d702
MS		 131 crst_table_free(mm, (unsigned long *) pgd);
132 }
133 update_mm(mm, current);
134}
135#endif
136
e5992f2e
MS		 137#ifdef CONFIG_PGSTE
138
139/**
140 * gmap_alloc - allocate a guest address space
141 * @mm: pointer to the parent mm_struct
142 *
143 * Returns a guest address space structure.
144 */
145struct gmap *gmap_alloc(struct mm_struct *mm)
36409f63 146{
e5992f2e
MS		 147 struct gmap *gmap;
148 struct page *page;
149 unsigned long *table;
36409f63 150
e5992f2e
MS		 151 gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
152 if (!gmap)
153 goto out;
154 INIT_LIST_HEAD(&gmap->crst_list);
155 gmap->mm = mm;
156 page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
157 if (!page)
158 goto out_free;
159 list_add(&page->lru, &gmap->crst_list);
160 table = (unsigned long *) page_to_phys(page);
161 crst_table_init(table, _REGION1_ENTRY_EMPTY);
162 gmap->table = table;
163 list_add(&gmap->list, &mm->context.gmap_list);
164 return gmap;
165
166out_free:
167 kfree(gmap);
168out:
169 return NULL;
36409f63 170}
e5992f2e 171EXPORT_SYMBOL_GPL(gmap_alloc);
36409f63 172
e5992f2e
MS		 173static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table)
174{
175 struct gmap_pgtable *mp;
176 struct gmap_rmap *rmap;
177 struct page *page;
178
179 if (*table & _SEGMENT_ENTRY_INV)
180 return 0;
181 page = pfn_to_page(*table >> PAGE_SHIFT);
182 mp = (struct gmap_pgtable *) page->index;
183 list_for_each_entry(rmap, &mp->mapper, list) {
184 if (rmap->entry != table)
185 continue;
186 list_del(&rmap->list);
187 kfree(rmap);
188 break;
189 }
190 *table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
191 return 1;
192}
193
194static void gmap_flush_tlb(struct gmap *gmap)
195{
196 if (MACHINE_HAS_IDTE)
197 __tlb_flush_idte((unsigned long) gmap->table |
198 _ASCE_TYPE_REGION1);
199 else
200 __tlb_flush_global();
201}
202
203/**
204 * gmap_free - free a guest address space
205 * @gmap: pointer to the guest address space structure
3610cce8 206 */
e5992f2e
MS		 207void gmap_free(struct gmap *gmap)
208{
209 struct page *page, *next;
210 unsigned long *table;
211 int i;
212
213
214 /* Flush tlb. */
215 if (MACHINE_HAS_IDTE)
216 __tlb_flush_idte((unsigned long) gmap->table |
217 _ASCE_TYPE_REGION1);
218 else
219 __tlb_flush_global();
220
221 /* Free all segment & region tables. */
222 down_read(&gmap->mm->mmap_sem);
223 list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
224 table = (unsigned long *) page_to_phys(page);
225 if ((*table & _REGION_ENTRY_TYPE_MASK) == 0)
226 /* Remove gmap rmap structures for segment table. */
227 for (i = 0; i < PTRS_PER_PMD; i++, table++)
228 gmap_unlink_segment(gmap, table);
229 __free_pages(page, ALLOC_ORDER);
230 }
231 up_read(&gmap->mm->mmap_sem);
232 list_del(&gmap->list);
233 kfree(gmap);
234}
235EXPORT_SYMBOL_GPL(gmap_free);
236
237/**
238 * gmap_enable - switch primary space to the guest address space
239 * @gmap: pointer to the guest address space structure
240 */
241void gmap_enable(struct gmap *gmap)
242{
243 /* Load primary space page table origin. */
244 S390_lowcore.user_asce = _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH |
245 _ASCE_USER_BITS | __pa(gmap->table);
246 asm volatile("lctlg 1,1,%0\n" : : "m" (S390_lowcore.user_asce) );
247 S390_lowcore.gmap = (unsigned long) gmap;
248}
249EXPORT_SYMBOL_GPL(gmap_enable);
250
251/**
252 * gmap_disable - switch back to the standard primary address space
253 * @gmap: pointer to the guest address space structure
254 */
255void gmap_disable(struct gmap *gmap)
256{
257 /* Load primary space page table origin. */
258 S390_lowcore.user_asce =
259 gmap->mm->context.asce_bits | __pa(gmap->mm->pgd);
260 asm volatile("lctlg 1,1,%0\n" : : "m" (S390_lowcore.user_asce) );
261 S390_lowcore.gmap = 0UL;
262}
263EXPORT_SYMBOL_GPL(gmap_disable);
264
265static int gmap_alloc_table(struct gmap *gmap,
266 unsigned long *table, unsigned long init)
267{
268 struct page *page;
269 unsigned long *new;
270
271 page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
272 if (!page)
273 return -ENOMEM;
274 new = (unsigned long *) page_to_phys(page);
275 crst_table_init(new, init);
276 down_read(&gmap->mm->mmap_sem);
277 if (*table & _REGION_ENTRY_INV) {
278 list_add(&page->lru, &gmap->crst_list);
279 *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
280 (*table & _REGION_ENTRY_TYPE_MASK);
281 } else
282 __free_pages(page, ALLOC_ORDER);
283 up_read(&gmap->mm->mmap_sem);
284 return 0;
285}
286
287/**
288 * gmap_unmap_segment - unmap segment from the guest address space
289 * @gmap: pointer to the guest address space structure
290 * @addr: address in the guest address space
291 * @len: length of the memory area to unmap
292 *
293 * Returns 0 if the unmap succeded, -EINVAL if not.
294 */
295int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
296{
297 unsigned long *table;
298 unsigned long off;
299 int flush;
300
301 if ((to | len) & (PMD_SIZE - 1))
302 return -EINVAL;
303 if (len == 0 || to + len < to)
304 return -EINVAL;
305
306 flush = 0;
307 down_read(&gmap->mm->mmap_sem);
308 for (off = 0; off < len; off += PMD_SIZE) {
309 /* Walk the guest addr space page table */
310 table = gmap->table + (((to + off) >> 53) & 0x7ff);
311 if (*table & _REGION_ENTRY_INV)
312 return 0;
313 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
314 table = table + (((to + off) >> 42) & 0x7ff);
315 if (*table & _REGION_ENTRY_INV)
316 return 0;
317 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
318 table = table + (((to + off) >> 31) & 0x7ff);
319 if (*table & _REGION_ENTRY_INV)
320 return 0;
321 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
322 table = table + (((to + off) >> 20) & 0x7ff);
323
324 /* Clear segment table entry in guest address space. */
325 flush |= gmap_unlink_segment(gmap, table);
326 *table = _SEGMENT_ENTRY_INV;
327 }
328 up_read(&gmap->mm->mmap_sem);
329 if (flush)
330 gmap_flush_tlb(gmap);
331 return 0;
332}
333EXPORT_SYMBOL_GPL(gmap_unmap_segment);
334
335/**
336 * gmap_mmap_segment - map a segment to the guest address space
337 * @gmap: pointer to the guest address space structure
338 * @from: source address in the parent address space
339 * @to: target address in the guest address space
340 *
341 * Returns 0 if the mmap succeded, -EINVAL or -ENOMEM if not.
342 */
343int gmap_map_segment(struct gmap *gmap, unsigned long from,
344 unsigned long to, unsigned long len)
345{
346 unsigned long *table;
347 unsigned long off;
348 int flush;
349
350 if ((from | to | len) & (PMD_SIZE - 1))
351 return -EINVAL;
352 if (len == 0 || from + len > PGDIR_SIZE ||
353 from + len < from || to + len < to)
354 return -EINVAL;
355
356 flush = 0;
357 down_read(&gmap->mm->mmap_sem);
358 for (off = 0; off < len; off += PMD_SIZE) {
359 /* Walk the gmap address space page table */
360 table = gmap->table + (((to + off) >> 53) & 0x7ff);
361 if ((*table & _REGION_ENTRY_INV) &&
362 gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY))
363 goto out_unmap;
364 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
365 table = table + (((to + off) >> 42) & 0x7ff);
366 if ((*table & _REGION_ENTRY_INV) &&
367 gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY))
368 goto out_unmap;
369 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
370 table = table + (((to + off) >> 31) & 0x7ff);
371 if ((*table & _REGION_ENTRY_INV) &&
372 gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY))
373 goto out_unmap;
374 table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN);
375 table = table + (((to + off) >> 20) & 0x7ff);
376
377 /* Store 'from' address in an invalid segment table entry. */
378 flush |= gmap_unlink_segment(gmap, table);
379 *table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | (from + off);
380 }
381 up_read(&gmap->mm->mmap_sem);
382 if (flush)
383 gmap_flush_tlb(gmap);
384 return 0;
385
386out_unmap:
387 up_read(&gmap->mm->mmap_sem);
388 gmap_unmap_segment(gmap, to, len);
389 return -ENOMEM;
390}
391EXPORT_SYMBOL_GPL(gmap_map_segment);
392
393unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
394{
395 unsigned long *table, vmaddr, segment;
396 struct mm_struct *mm;
397 struct gmap_pgtable *mp;
398 struct gmap_rmap *rmap;
399 struct vm_area_struct *vma;
400 struct page *page;
401 pgd_t *pgd;
402 pud_t *pud;
403 pmd_t *pmd;
404
405 current->thread.gmap_addr = address;
406 mm = gmap->mm;
407 /* Walk the gmap address space page table */
408 table = gmap->table + ((address >> 53) & 0x7ff);
409 if (unlikely(*table & _REGION_ENTRY_INV))
410 return -EFAULT;
411 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
412 table = table + ((address >> 42) & 0x7ff);
413 if (unlikely(*table & _REGION_ENTRY_INV))
414 return -EFAULT;
415 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
416 table = table + ((address >> 31) & 0x7ff);
417 if (unlikely(*table & _REGION_ENTRY_INV))
418 return -EFAULT;
419 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
420 table = table + ((address >> 20) & 0x7ff);
421
422 /* Convert the gmap address to an mm address. */
423 segment = *table;
424 if (likely(!(segment & _SEGMENT_ENTRY_INV))) {
425 page = pfn_to_page(segment >> PAGE_SHIFT);
426 mp = (struct gmap_pgtable *) page->index;
427 return mp->vmaddr | (address & ~PMD_MASK);
428 } else if (segment & _SEGMENT_ENTRY_RO) {
429 vmaddr = segment & _SEGMENT_ENTRY_ORIGIN;
430 vma = find_vma(mm, vmaddr);
431 if (!vma || vma->vm_start > vmaddr)
432 return -EFAULT;
433
434 /* Walk the parent mm page table */
435 pgd = pgd_offset(mm, vmaddr);
436 pud = pud_alloc(mm, pgd, vmaddr);
437 if (!pud)
438 return -ENOMEM;
439 pmd = pmd_alloc(mm, pud, vmaddr);
440 if (!pmd)
441 return -ENOMEM;
442 if (!pmd_present(*pmd) &&
443 __pte_alloc(mm, vma, pmd, vmaddr))
444 return -ENOMEM;
445 /* pmd now points to a valid segment table entry. */
446 rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT);
447 if (!rmap)
448 return -ENOMEM;
449 /* Link gmap segment table entry location to page table. */
450 page = pmd_page(*pmd);
451 mp = (struct gmap_pgtable *) page->index;
452 rmap->entry = table;
453 list_add(&rmap->list, &mp->mapper);
454 /* Set gmap segment table entry to page table. */
455 *table = pmd_val(*pmd) & PAGE_MASK;
456 return vmaddr | (address & ~PMD_MASK);
457 }
458 return -EFAULT;
459
460}
461EXPORT_SYMBOL_GPL(gmap_fault);
462
463void gmap_unmap_notifier(struct mm_struct *mm, unsigned long *table)
464{
465 struct gmap_rmap *rmap, *next;
466 struct gmap_pgtable *mp;
467 struct page *page;
468 int flush;
469
470 flush = 0;
471 spin_lock(&mm->page_table_lock);
472 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
473 mp = (struct gmap_pgtable *) page->index;
474 list_for_each_entry_safe(rmap, next, &mp->mapper, list) {
475 *rmap->entry =
476 _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
477 list_del(&rmap->list);
478 kfree(rmap);
479 flush = 1;
480 }
481 spin_unlock(&mm->page_table_lock);
482 if (flush)
483 __tlb_flush_global();
484}
485
486static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
487 unsigned long vmaddr)
36409f63
MS		 488{
489 struct page *page;
490 unsigned long *table;
e5992f2e 491 struct gmap_pgtable *mp;
36409f63
MS		 492
493 page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
494 if (!page)
495 return NULL;
e5992f2e
MS		 496 mp = kmalloc(sizeof(*mp), GFP_KERNEL|__GFP_REPEAT);
497 if (!mp) {
498 __free_page(page);
499 return NULL;
500 }
36409f63 501 pgtable_page_ctor(page);
e5992f2e
MS		 502 mp->vmaddr = vmaddr & PMD_MASK;
503 INIT_LIST_HEAD(&mp->mapper);
504 page->index = (unsigned long) mp;
36409f63
MS		 505 atomic_set(&page->_mapcount, 3);
506 table = (unsigned long *) page_to_phys(page);
507 clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/2);
508 clear_table(table + PTRS_PER_PTE, 0, PAGE_SIZE/2);
509 return table;
510}
511
512static inline void page_table_free_pgste(unsigned long *table)
513{
514 struct page *page;
e5992f2e 515 struct gmap_pgtable *mp;
36409f63
MS		 516
517 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
e5992f2e
MS		 518 mp = (struct gmap_pgtable *) page->index;
519 BUG_ON(!list_empty(&mp->mapper));
36409f63
MS		 520 pgtable_page_ctor(page);
521 atomic_set(&page->_mapcount, -1);
e5992f2e 522 kfree(mp);
36409f63
MS		 523 __free_page(page);
524}
36409f63 525
e5992f2e
MS		 526#else /* CONFIG_PGSTE */
527
528static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
529 unsigned long vmaddr)
530{
531}
532
533static inline void page_table_free_pgste(unsigned long *table)
534{
535}
536
537static inline void gmap_unmap_notifier(struct mm_struct *mm,
538 unsigned long *table)
539{
540}
541
542#endif /* CONFIG_PGSTE */
543
544static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
545{
546 unsigned int old, new;
547
548 do {
549 old = atomic_read(v);
550 new = old ^ bits;
551 } while (atomic_cmpxchg(v, old, new) != old);
552 return new;
553}
554
555/*
556 * page table entry allocation/free routines.
557 */
558unsigned long *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr)
3610cce8 559{
146e4b3c 560 struct page *page;
3610cce8 561 unsigned long *table;
36409f63 562 unsigned int mask, bit;
3610cce8 563
36409f63 564 if (mm_has_pgste(mm))
e5992f2e 565 return page_table_alloc_pgste(mm, vmaddr);
36409f63 566 /* Allocate fragments of a 4K page as 1K/2K page table */
80217147 567 spin_lock_bh(&mm->context.list_lock);
36409f63 568 mask = FRAG_MASK;
146e4b3c
MS		 569 if (!list_empty(&mm->context.pgtable_list)) {
570 page = list_first_entry(&mm->context.pgtable_list,
571 struct page, lru);
36409f63
MS		 572 table = (unsigned long *) page_to_phys(page);
573 mask = atomic_read(&page->_mapcount);
574 mask = mask | (mask >> 4);
146e4b3c 575 }
36409f63 576 if ((mask & FRAG_MASK) == FRAG_MASK) {
80217147 577 spin_unlock_bh(&mm->context.list_lock);
146e4b3c
MS		 578 page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
579 if (!page)
3610cce8 580 return NULL;
146e4b3c 581 pgtable_page_ctor(page);
36409f63 582 atomic_set(&page->_mapcount, 1);
146e4b3c 583 table = (unsigned long *) page_to_phys(page);
36409f63 584 clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
80217147 585 spin_lock_bh(&mm->context.list_lock);
146e4b3c 586 list_add(&page->lru, &mm->context.pgtable_list);
36409f63
MS		 587 } else {
588 for (bit = 1; mask & bit; bit <<= 1)
589 table += PTRS_PER_PTE;
590 mask = atomic_xor_bits(&page->_mapcount, bit);
591 if ((mask & FRAG_MASK) == FRAG_MASK)
592 list_del(&page->lru);
3610cce8 593 }
80217147 594 spin_unlock_bh(&mm->context.list_lock);
3610cce8
MS		 595 return table;
596}
597
36409f63 598void page_table_free(struct mm_struct *mm, unsigned long *table)
80217147
MS		 599{
600 struct page *page;
36409f63 601 unsigned int bit, mask;
80217147 602
e5992f2e
MS		 603 if (mm_has_pgste(mm)) {
604 gmap_unmap_notifier(mm, table);
36409f63 605 return page_table_free_pgste(table);
e5992f2e 606 }
36409f63 607 /* Free 1K/2K page table fragment of a 4K page */
80217147 608 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
36409f63
MS		 609 bit = 1 << ((__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t)));
610 spin_lock_bh(&mm->context.list_lock);
611 if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
612 list_del(&page->lru);
613 mask = atomic_xor_bits(&page->_mapcount, bit);
614 if (mask & FRAG_MASK)
615 list_add(&page->lru, &mm->context.pgtable_list);
616 spin_unlock_bh(&mm->context.list_lock);
617 if (mask == 0) {
80217147 618 pgtable_page_dtor(page);
36409f63 619 atomic_set(&page->_mapcount, -1);
80217147
MS		 620 __free_page(page);
621 }
622}
623
36409f63
MS		 624#ifdef CONFIG_HAVE_RCU_TABLE_FREE
625
626static void __page_table_free_rcu(void *table, unsigned bit)
3610cce8 627{
146e4b3c 628 struct page *page;
3610cce8 629
36409f63
MS		 630 if (bit == FRAG_MASK)
631 return page_table_free_pgste(table);
36409f63 632 /* Free 1K/2K page table fragment of a 4K page */
146e4b3c 633 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
36409f63 634 if (atomic_xor_bits(&page->_mapcount, bit) == 0) {
146e4b3c 635 pgtable_page_dtor(page);
36409f63 636 atomic_set(&page->_mapcount, -1);
146e4b3c
MS		 637 __free_page(page);
638 }
639}
3610cce8 640
36409f63 641void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table)
80217147 642{
36409f63 643 struct mm_struct *mm;
80217147 644 struct page *page;
36409f63 645 unsigned int bit, mask;
80217147 646
36409f63 647 mm = tlb->mm;
36409f63 648 if (mm_has_pgste(mm)) {
e5992f2e 649 gmap_unmap_notifier(mm, table);
36409f63
MS		 650 table = (unsigned long *) (__pa(table) | FRAG_MASK);
651 tlb_remove_table(tlb, table);
652 return;
80217147 653 }
36409f63 654 bit = 1 << ((__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t)));
80217147
MS		 655 page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
656 spin_lock_bh(&mm->context.list_lock);
36409f63
MS		 657 if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK)
658 list_del(&page->lru);
659 mask = atomic_xor_bits(&page->_mapcount, bit | (bit << 4));
660 if (mask & FRAG_MASK)
661 list_add_tail(&page->lru, &mm->context.pgtable_list);
80217147 662 spin_unlock_bh(&mm->context.list_lock);
36409f63
MS		 663 table = (unsigned long *) (__pa(table) | (bit << 4));
664 tlb_remove_table(tlb, table);
665}
666
667void __tlb_remove_table(void *_table)
668{
669 void *table = (void *)((unsigned long) _table & PAGE_MASK);
670 unsigned type = (unsigned long) _table & ~PAGE_MASK;
671
672 if (type)
673 __page_table_free_rcu(table, type);
674 else
675 free_pages((unsigned long) table, ALLOC_ORDER);
80217147
MS		 676}
677
36409f63
MS		 678#endif
679
402b0862
CO		 680/*
681 * switch on pgstes for its userspace process (for kvm)
682 */
683int s390_enable_sie(void)
684{
685 struct task_struct *tsk = current;
74b6b522 686 struct mm_struct *mm, *old_mm;
402b0862 687
702d9e58 688 /* Do we have switched amode? If no, we cannot do sie */
b11b5334 689 if (user_mode == HOME_SPACE_MODE)
702d9e58
CO		 690 return -EINVAL;
691
74b6b522 692 /* Do we have pgstes? if yes, we are done */
36409f63 693 if (mm_has_pgste(tsk->mm))
74b6b522 694 return 0;
402b0862 695
74b6b522
CB		 696 /* lets check if we are allowed to replace the mm */
697 task_lock(tsk);
402b0862 698 if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
52a21f2c
MS		 699#ifdef CONFIG_AIO
700 !hlist_empty(&tsk->mm->ioctx_list) ||
701#endif
702 tsk->mm != tsk->active_mm) {
74b6b522
CB		 703 task_unlock(tsk);
704 return -EINVAL;
705 }
706 task_unlock(tsk);
402b0862 707
250cf776
CB		 708 /* we copy the mm and let dup_mm create the page tables with_pgstes */
709 tsk->mm->context.alloc_pgste = 1;
402b0862 710 mm = dup_mm(tsk);
250cf776 711 tsk->mm->context.alloc_pgste = 0;
402b0862 712 if (!mm)
74b6b522
CB		 713 return -ENOMEM;
714
250cf776 715 /* Now lets check again if something happened */
74b6b522
CB		 716 task_lock(tsk);
717 if (!tsk->mm || atomic_read(&tsk->mm->mm_users) > 1 ||
52a21f2c
MS		 718#ifdef CONFIG_AIO
719 !hlist_empty(&tsk->mm->ioctx_list) ||
720#endif
721 tsk->mm != tsk->active_mm) {
74b6b522
CB		 722 mmput(mm);
723 task_unlock(tsk);
724 return -EINVAL;
725 }
726
727 /* ok, we are alone. No ptrace, no threads, etc. */
728 old_mm = tsk->mm;
402b0862
CO		 729 tsk->mm = tsk->active_mm = mm;
730 preempt_disable();
731 update_mm(mm, tsk);
e05ef9bd
CB		 732 atomic_inc(&mm->context.attach_count);
733 atomic_dec(&old_mm->context.attach_count);
005f8eee 734 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
402b0862 735 preempt_enable();
402b0862 736 task_unlock(tsk);
74b6b522
CB		 737 mmput(old_mm);
738 return 0;
402b0862
CO		 739}
740EXPORT_SYMBOL_GPL(s390_enable_sie);
7db11a36 741
87458ff4 742#if defined(CONFIG_DEBUG_PAGEALLOC) && defined(CONFIG_HIBERNATION)
7db11a36
HJP		 743bool kernel_page_present(struct page *page)
744{
745 unsigned long addr;
746 int cc;
747
748 addr = page_to_phys(page);
87458ff4
HC		 749 asm volatile(
750 " lra %1,0(%1)\n"
751 " ipm %0\n"
752 " srl %0,28"
753 : "=d" (cc), "+a" (addr) : : "cc");
7db11a36
HJP		 754 return cc == 0;
755}
87458ff4 756#endif /* CONFIG_HIBERNATION && CONFIG_DEBUG_PAGEALLOC */
kernel source for telekom puls (alcatel/mediatek)