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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * address space "slices" (meta-segments) support
4 *
5 * Copyright (C) 2007 Benjamin Herrenschmidt, IBM Corporation.
6 *
7 * Based on hugetlb implementation
8 *
9 * Copyright (C) 2003 David Gibson, IBM Corporation.
10 */
11
12#undef DEBUG
13
14#include <linux/kernel.h>
15#include <linux/mm.h>
16#include <linux/pagemap.h>
17#include <linux/err.h>
18#include <linux/spinlock.h>
19#include <linux/export.h>
20#include <linux/hugetlb.h>
21#include <linux/sched/mm.h>
22#include <linux/security.h>
23#include <asm/mman.h>
24#include <asm/mmu.h>
25#include <asm/copro.h>
26#include <asm/hugetlb.h>
27#include <asm/mmu_context.h>
28
29static DEFINE_SPINLOCK(slice_convert_lock);
30
31#ifdef DEBUG
32int _slice_debug = 1;
33
34static void slice_print_mask(const char *label, const struct slice_mask *mask)
35{
36 if (!_slice_debug)
37 return;
38 pr_devel("%s low_slice: %*pbl\n", label,
39 (int)SLICE_NUM_LOW, &mask->low_slices);
40 pr_devel("%s high_slice: %*pbl\n", label,
41 (int)SLICE_NUM_HIGH, mask->high_slices);
42}
43
44#define slice_dbg(fmt...) do { if (_slice_debug) pr_devel(fmt); } while (0)
45
46#else
47
48static void slice_print_mask(const char *label, const struct slice_mask *mask) {}
49#define slice_dbg(fmt...)
50
51#endif
52
53static inline bool slice_addr_is_low(unsigned long addr)
54{
55 u64 tmp = (u64)addr;
56
57 return tmp < SLICE_LOW_TOP;
58}
59
60static void slice_range_to_mask(unsigned long start, unsigned long len,
61 struct slice_mask *ret)
62{
63 unsigned long end = start + len - 1;
64
65 ret->low_slices = 0;
66 if (SLICE_NUM_HIGH)
67 bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
68
69 if (slice_addr_is_low(start)) {
70 unsigned long mend = min(end,
71 (unsigned long)(SLICE_LOW_TOP - 1));
72
73 ret->low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
74 - (1u << GET_LOW_SLICE_INDEX(start));
75 }
76
77 if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) {
78 unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
79 unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
80 unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
81
82 bitmap_set(ret->high_slices, start_index, count);
83 }
84}
85
86static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
87 unsigned long len)
88{
89 struct vm_area_struct *vma;
90
91 if ((mm_ctx_slb_addr_limit(&mm->context) - len) < addr)
92 return 0;
93 vma = find_vma(mm, addr);
94 return (!vma || (addr + len) <= vm_start_gap(vma));
95}
96
97static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice)
98{
99 return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT,
100 1ul << SLICE_LOW_SHIFT);
101}
102
103static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
104{
105 unsigned long start = slice << SLICE_HIGH_SHIFT;
106 unsigned long end = start + (1ul << SLICE_HIGH_SHIFT);
107
108 /* Hack, so that each addresses is controlled by exactly one
109 * of the high or low area bitmaps, the first high area starts
110 * at 4GB, not 0 */
111 if (start == 0)
112 start = (unsigned long)SLICE_LOW_TOP;
113
114 return !slice_area_is_free(mm, start, end - start);
115}
116
117static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret,
118 unsigned long high_limit)
119{
120 unsigned long i;
121
122 ret->low_slices = 0;
123 if (SLICE_NUM_HIGH)
124 bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
125
126 for (i = 0; i < SLICE_NUM_LOW; i++)
127 if (!slice_low_has_vma(mm, i))
128 ret->low_slices |= 1u << i;
129
130 if (slice_addr_is_low(high_limit - 1))
131 return;
132
133 for (i = 0; i < GET_HIGH_SLICE_INDEX(high_limit); i++)
134 if (!slice_high_has_vma(mm, i))
135 __set_bit(i, ret->high_slices);
136}
137
138static bool slice_check_range_fits(struct mm_struct *mm,
139 const struct slice_mask *available,
140 unsigned long start, unsigned long len)
141{
142 unsigned long end = start + len - 1;
143 u64 low_slices = 0;
144
145 if (slice_addr_is_low(start)) {
146 unsigned long mend = min(end,
147 (unsigned long)(SLICE_LOW_TOP - 1));
148
149 low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
150 - (1u << GET_LOW_SLICE_INDEX(start));
151 }
152 if ((low_slices & available->low_slices) != low_slices)
153 return false;
154
155 if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) {
156 unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
157 unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
158 unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
159 unsigned long i;
160
161 for (i = start_index; i < start_index + count; i++) {
162 if (!test_bit(i, available->high_slices))
163 return false;
164 }
165 }
166
167 return true;
168}
169
170static void slice_flush_segments(void *parm)
171{
172#ifdef CONFIG_PPC64
173 struct mm_struct *mm = parm;
174 unsigned long flags;
175
176 if (mm != current->active_mm)
177 return;
178
179 copy_mm_to_paca(current->active_mm);
180
181 local_irq_save(flags);
182 slb_flush_and_restore_bolted();
183 local_irq_restore(flags);
184#endif
185}
186
187static void slice_convert(struct mm_struct *mm,
188 const struct slice_mask *mask, int psize)
189{
190 int index, mask_index;
191 /* Write the new slice psize bits */
192 unsigned char *hpsizes, *lpsizes;
193 struct slice_mask *psize_mask, *old_mask;
194 unsigned long i, flags;
195 int old_psize;
196
197 slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
198 slice_print_mask(" mask", mask);
199
200 psize_mask = slice_mask_for_size(&mm->context, psize);
201
202 /* We need to use a spinlock here to protect against
203 * concurrent 64k -> 4k demotion ...
204 */
205 spin_lock_irqsave(&slice_convert_lock, flags);
206
207 lpsizes = mm_ctx_low_slices(&mm->context);
208 for (i = 0; i < SLICE_NUM_LOW; i++) {
209 if (!(mask->low_slices & (1u << i)))
210 continue;
211
212 mask_index = i & 0x1;
213 index = i >> 1;
214
215 /* Update the slice_mask */
216 old_psize = (lpsizes[index] >> (mask_index * 4)) & 0xf;
217 old_mask = slice_mask_for_size(&mm->context, old_psize);
218 old_mask->low_slices &= ~(1u << i);
219 psize_mask->low_slices |= 1u << i;
220
221 /* Update the sizes array */
222 lpsizes[index] = (lpsizes[index] & ~(0xf << (mask_index * 4))) |
223 (((unsigned long)psize) << (mask_index * 4));
224 }
225
226 hpsizes = mm_ctx_high_slices(&mm->context);
227 for (i = 0; i < GET_HIGH_SLICE_INDEX(mm_ctx_slb_addr_limit(&mm->context)); i++) {
228 if (!test_bit(i, mask->high_slices))
229 continue;
230
231 mask_index = i & 0x1;
232 index = i >> 1;
233
234 /* Update the slice_mask */
235 old_psize = (hpsizes[index] >> (mask_index * 4)) & 0xf;
236 old_mask = slice_mask_for_size(&mm->context, old_psize);
237 __clear_bit(i, old_mask->high_slices);
238 __set_bit(i, psize_mask->high_slices);
239
240 /* Update the sizes array */
241 hpsizes[index] = (hpsizes[index] & ~(0xf << (mask_index * 4))) |
242 (((unsigned long)psize) << (mask_index * 4));
243 }
244
245 slice_dbg(" lsps=%lx, hsps=%lx\n",
246 (unsigned long)mm_ctx_low_slices(&mm->context),
247 (unsigned long)mm_ctx_high_slices(&mm->context));
248
249 spin_unlock_irqrestore(&slice_convert_lock, flags);
250
251 copro_flush_all_slbs(mm);
252}
253
254/*
255 * Compute which slice addr is part of;
256 * set *boundary_addr to the start or end boundary of that slice
257 * (depending on 'end' parameter);
258 * return boolean indicating if the slice is marked as available in the
259 * 'available' slice_mark.
260 */
261static bool slice_scan_available(unsigned long addr,
262 const struct slice_mask *available,
263 int end, unsigned long *boundary_addr)
264{
265 unsigned long slice;
266 if (slice_addr_is_low(addr)) {
267 slice = GET_LOW_SLICE_INDEX(addr);
268 *boundary_addr = (slice + end) << SLICE_LOW_SHIFT;
269 return !!(available->low_slices & (1u << slice));
270 } else {
271 slice = GET_HIGH_SLICE_INDEX(addr);
272 *boundary_addr = (slice + end) ?
273 ((slice + end) << SLICE_HIGH_SHIFT) : SLICE_LOW_TOP;
274 return !!test_bit(slice, available->high_slices);
275 }
276}
277
278static unsigned long slice_find_area_bottomup(struct mm_struct *mm,
279 unsigned long len,
280 const struct slice_mask *available,
281 int psize, unsigned long high_limit)
282{
283 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
284 unsigned long addr, found, next_end;
285 struct vm_unmapped_area_info info;
286
287 info.flags = 0;
288 info.length = len;
289 info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
290 info.align_offset = 0;
291
292 addr = TASK_UNMAPPED_BASE;
293 /*
294 * Check till the allow max value for this mmap request
295 */
296 while (addr < high_limit) {
297 info.low_limit = addr;
298 if (!slice_scan_available(addr, available, 1, &addr))
299 continue;
300
301 next_slice:
302 /*
303 * At this point [info.low_limit; addr) covers
304 * available slices only and ends at a slice boundary.
305 * Check if we need to reduce the range, or if we can
306 * extend it to cover the next available slice.
307 */
308 if (addr >= high_limit)
309 addr = high_limit;
310 else if (slice_scan_available(addr, available, 1, &next_end)) {
311 addr = next_end;
312 goto next_slice;
313 }
314 info.high_limit = addr;
315
316 found = vm_unmapped_area(&info);
317 if (!(found & ~PAGE_MASK))
318 return found;
319 }
320
321 return -ENOMEM;
322}
323
324static unsigned long slice_find_area_topdown(struct mm_struct *mm,
325 unsigned long len,
326 const struct slice_mask *available,
327 int psize, unsigned long high_limit)
328{
329 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
330 unsigned long addr, found, prev;
331 struct vm_unmapped_area_info info;
332 unsigned long min_addr = max(PAGE_SIZE, mmap_min_addr);
333
334 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
335 info.length = len;
336 info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
337 info.align_offset = 0;
338
339 addr = mm->mmap_base;
340 /*
341 * If we are trying to allocate above DEFAULT_MAP_WINDOW
342 * Add the different to the mmap_base.
343 * Only for that request for which high_limit is above
344 * DEFAULT_MAP_WINDOW we should apply this.
345 */
346 if (high_limit > DEFAULT_MAP_WINDOW)
347 addr += mm_ctx_slb_addr_limit(&mm->context) - DEFAULT_MAP_WINDOW;
348
349 while (addr > min_addr) {
350 info.high_limit = addr;
351 if (!slice_scan_available(addr - 1, available, 0, &addr))
352 continue;
353
354 prev_slice:
355 /*
356 * At this point [addr; info.high_limit) covers
357 * available slices only and starts at a slice boundary.
358 * Check if we need to reduce the range, or if we can
359 * extend it to cover the previous available slice.
360 */
361 if (addr < min_addr)
362 addr = min_addr;
363 else if (slice_scan_available(addr - 1, available, 0, &prev)) {
364 addr = prev;
365 goto prev_slice;
366 }
367 info.low_limit = addr;
368
369 found = vm_unmapped_area(&info);
370 if (!(found & ~PAGE_MASK))
371 return found;
372 }
373
374 /*
375 * A failed mmap() very likely causes application failure,
376 * so fall back to the bottom-up function here. This scenario
377 * can happen with large stack limits and large mmap()
378 * allocations.
379 */
380 return slice_find_area_bottomup(mm, len, available, psize, high_limit);
381}
382
383
384static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
385 const struct slice_mask *mask, int psize,
386 int topdown, unsigned long high_limit)
387{
388 if (topdown)
389 return slice_find_area_topdown(mm, len, mask, psize, high_limit);
390 else
391 return slice_find_area_bottomup(mm, len, mask, psize, high_limit);
392}
393
394static inline void slice_copy_mask(struct slice_mask *dst,
395 const struct slice_mask *src)
396{
397 dst->low_slices = src->low_slices;
398 if (!SLICE_NUM_HIGH)
399 return;
400 bitmap_copy(dst->high_slices, src->high_slices, SLICE_NUM_HIGH);
401}
402
403static inline void slice_or_mask(struct slice_mask *dst,
404 const struct slice_mask *src1,
405 const struct slice_mask *src2)
406{
407 dst->low_slices = src1->low_slices | src2->low_slices;
408 if (!SLICE_NUM_HIGH)
409 return;
410 bitmap_or(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
411}
412
413static inline void slice_andnot_mask(struct slice_mask *dst,
414 const struct slice_mask *src1,
415 const struct slice_mask *src2)
416{
417 dst->low_slices = src1->low_slices & ~src2->low_slices;
418 if (!SLICE_NUM_HIGH)
419 return;
420 bitmap_andnot(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
421}
422
423#ifdef CONFIG_PPC_64K_PAGES
424#define MMU_PAGE_BASE MMU_PAGE_64K
425#else
426#define MMU_PAGE_BASE MMU_PAGE_4K
427#endif
428
429unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
430 unsigned long flags, unsigned int psize,
431 int topdown)
432{
433 struct slice_mask good_mask;
434 struct slice_mask potential_mask;
435 const struct slice_mask *maskp;
436 const struct slice_mask *compat_maskp = NULL;
437 int fixed = (flags & MAP_FIXED);
438 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
439 unsigned long page_size = 1UL << pshift;
440 struct mm_struct *mm = current->mm;
441 unsigned long newaddr;
442 unsigned long high_limit;
443
444 high_limit = DEFAULT_MAP_WINDOW;
445 if (addr >= high_limit || (fixed && (addr + len > high_limit)))
446 high_limit = TASK_SIZE;
447
448 if (len > high_limit)
449 return -ENOMEM;
450 if (len & (page_size - 1))
451 return -EINVAL;
452 if (fixed) {
453 if (addr & (page_size - 1))
454 return -EINVAL;
455 if (addr > high_limit - len)
456 return -ENOMEM;
457 }
458
459 if (high_limit > mm_ctx_slb_addr_limit(&mm->context)) {
460 /*
461 * Increasing the slb_addr_limit does not require
462 * slice mask cache to be recalculated because it should
463 * be already initialised beyond the old address limit.
464 */
465 mm_ctx_set_slb_addr_limit(&mm->context, high_limit);
466
467 on_each_cpu(slice_flush_segments, mm, 1);
468 }
469
470 /* Sanity checks */
471 BUG_ON(mm->task_size == 0);
472 BUG_ON(mm_ctx_slb_addr_limit(&mm->context) == 0);
473 VM_BUG_ON(radix_enabled());
474
475 slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize);
476 slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n",
477 addr, len, flags, topdown);
478
479 /* If hint, make sure it matches our alignment restrictions */
480 if (!fixed && addr) {
481 addr = _ALIGN_UP(addr, page_size);
482 slice_dbg(" aligned addr=%lx\n", addr);
483 /* Ignore hint if it's too large or overlaps a VMA */
484 if (addr > high_limit - len || addr < mmap_min_addr ||
485 !slice_area_is_free(mm, addr, len))
486 addr = 0;
487 }
488
489 /* First make up a "good" mask of slices that have the right size
490 * already
491 */
492 maskp = slice_mask_for_size(&mm->context, psize);
493
494 /*
495 * Here "good" means slices that are already the right page size,
496 * "compat" means slices that have a compatible page size (i.e.
497 * 4k in a 64k pagesize kernel), and "free" means slices without
498 * any VMAs.
499 *
500 * If MAP_FIXED:
501 * check if fits in good | compat => OK
502 * check if fits in good | compat | free => convert free
503 * else bad
504 * If have hint:
505 * check if hint fits in good => OK
506 * check if hint fits in good | free => convert free
507 * Otherwise:
508 * search in good, found => OK
509 * search in good | free, found => convert free
510 * search in good | compat | free, found => convert free.
511 */
512
513 /*
514 * If we support combo pages, we can allow 64k pages in 4k slices
515 * The mask copies could be avoided in most cases here if we had
516 * a pointer to good mask for the next code to use.
517 */
518 if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) {
519 compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K);
520 if (fixed)
521 slice_or_mask(&good_mask, maskp, compat_maskp);
522 else
523 slice_copy_mask(&good_mask, maskp);
524 } else {
525 slice_copy_mask(&good_mask, maskp);
526 }
527
528 slice_print_mask(" good_mask", &good_mask);
529 if (compat_maskp)
530 slice_print_mask(" compat_mask", compat_maskp);
531
532 /* First check hint if it's valid or if we have MAP_FIXED */
533 if (addr != 0 || fixed) {
534 /* Check if we fit in the good mask. If we do, we just return,
535 * nothing else to do
536 */
537 if (slice_check_range_fits(mm, &good_mask, addr, len)) {
538 slice_dbg(" fits good !\n");
539 newaddr = addr;
540 goto return_addr;
541 }
542 } else {
543 /* Now let's see if we can find something in the existing
544 * slices for that size
545 */
546 newaddr = slice_find_area(mm, len, &good_mask,
547 psize, topdown, high_limit);
548 if (newaddr != -ENOMEM) {
549 /* Found within the good mask, we don't have to setup,
550 * we thus return directly
551 */
552 slice_dbg(" found area at 0x%lx\n", newaddr);
553 goto return_addr;
554 }
555 }
556 /*
557 * We don't fit in the good mask, check what other slices are
558 * empty and thus can be converted
559 */
560 slice_mask_for_free(mm, &potential_mask, high_limit);
561 slice_or_mask(&potential_mask, &potential_mask, &good_mask);
562 slice_print_mask(" potential", &potential_mask);
563
564 if (addr != 0 || fixed) {
565 if (slice_check_range_fits(mm, &potential_mask, addr, len)) {
566 slice_dbg(" fits potential !\n");
567 newaddr = addr;
568 goto convert;
569 }
570 }
571
572 /* If we have MAP_FIXED and failed the above steps, then error out */
573 if (fixed)
574 return -EBUSY;
575
576 slice_dbg(" search...\n");
577
578 /* If we had a hint that didn't work out, see if we can fit
579 * anywhere in the good area.
580 */
581 if (addr) {
582 newaddr = slice_find_area(mm, len, &good_mask,
583 psize, topdown, high_limit);
584 if (newaddr != -ENOMEM) {
585 slice_dbg(" found area at 0x%lx\n", newaddr);
586 goto return_addr;
587 }
588 }
589
590 /* Now let's see if we can find something in the existing slices
591 * for that size plus free slices
592 */
593 newaddr = slice_find_area(mm, len, &potential_mask,
594 psize, topdown, high_limit);
595
596 if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && newaddr == -ENOMEM &&
597 psize == MMU_PAGE_64K) {
598 /* retry the search with 4k-page slices included */
599 slice_or_mask(&potential_mask, &potential_mask, compat_maskp);
600 newaddr = slice_find_area(mm, len, &potential_mask,
601 psize, topdown, high_limit);
602 }
603
604 if (newaddr == -ENOMEM)
605 return -ENOMEM;
606
607 slice_range_to_mask(newaddr, len, &potential_mask);
608 slice_dbg(" found potential area at 0x%lx\n", newaddr);
609 slice_print_mask(" mask", &potential_mask);
610
611 convert:
612 /*
613 * Try to allocate the context before we do slice convert
614 * so that we handle the context allocation failure gracefully.
615 */
616 if (need_extra_context(mm, newaddr)) {
617 if (alloc_extended_context(mm, newaddr) < 0)
618 return -ENOMEM;
619 }
620
621 slice_andnot_mask(&potential_mask, &potential_mask, &good_mask);
622 if (compat_maskp && !fixed)
623 slice_andnot_mask(&potential_mask, &potential_mask, compat_maskp);
624 if (potential_mask.low_slices ||
625 (SLICE_NUM_HIGH &&
626 !bitmap_empty(potential_mask.high_slices, SLICE_NUM_HIGH))) {
627 slice_convert(mm, &potential_mask, psize);
628 if (psize > MMU_PAGE_BASE)
629 on_each_cpu(slice_flush_segments, mm, 1);
630 }
631 return newaddr;
632
633return_addr:
634 if (need_extra_context(mm, newaddr)) {
635 if (alloc_extended_context(mm, newaddr) < 0)
636 return -ENOMEM;
637 }
638 return newaddr;
639}
640EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
641
642unsigned long arch_get_unmapped_area(struct file *filp,
643 unsigned long addr,
644 unsigned long len,
645 unsigned long pgoff,
646 unsigned long flags)
647{
648 return slice_get_unmapped_area(addr, len, flags,
649 mm_ctx_user_psize(¤t->mm->context), 0);
650}
651
652unsigned long arch_get_unmapped_area_topdown(struct file *filp,
653 const unsigned long addr0,
654 const unsigned long len,
655 const unsigned long pgoff,
656 const unsigned long flags)
657{
658 return slice_get_unmapped_area(addr0, len, flags,
659 mm_ctx_user_psize(¤t->mm->context), 1);
660}
661
662unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
663{
664 unsigned char *psizes;
665 int index, mask_index;
666
667 VM_BUG_ON(radix_enabled());
668
669 if (slice_addr_is_low(addr)) {
670 psizes = mm_ctx_low_slices(&mm->context);
671 index = GET_LOW_SLICE_INDEX(addr);
672 } else {
673 psizes = mm_ctx_high_slices(&mm->context);
674 index = GET_HIGH_SLICE_INDEX(addr);
675 }
676 mask_index = index & 0x1;
677 return (psizes[index >> 1] >> (mask_index * 4)) & 0xf;
678}
679EXPORT_SYMBOL_GPL(get_slice_psize);
680
681void slice_init_new_context_exec(struct mm_struct *mm)
682{
683 unsigned char *hpsizes, *lpsizes;
684 struct slice_mask *mask;
685 unsigned int psize = mmu_virtual_psize;
686
687 slice_dbg("slice_init_new_context_exec(mm=%p)\n", mm);
688
689 /*
690 * In the case of exec, use the default limit. In the
691 * case of fork it is just inherited from the mm being
692 * duplicated.
693 */
694 mm_ctx_set_slb_addr_limit(&mm->context, SLB_ADDR_LIMIT_DEFAULT);
695 mm_ctx_set_user_psize(&mm->context, psize);
696
697 /*
698 * Set all slice psizes to the default.
699 */
700 lpsizes = mm_ctx_low_slices(&mm->context);
701 memset(lpsizes, (psize << 4) | psize, SLICE_NUM_LOW >> 1);
702
703 hpsizes = mm_ctx_high_slices(&mm->context);
704 memset(hpsizes, (psize << 4) | psize, SLICE_NUM_HIGH >> 1);
705
706 /*
707 * Slice mask cache starts zeroed, fill the default size cache.
708 */
709 mask = slice_mask_for_size(&mm->context, psize);
710 mask->low_slices = ~0UL;
711 if (SLICE_NUM_HIGH)
712 bitmap_fill(mask->high_slices, SLICE_NUM_HIGH);
713}
714
715#ifdef CONFIG_PPC_BOOK3S_64
716void slice_setup_new_exec(void)
717{
718 struct mm_struct *mm = current->mm;
719
720 slice_dbg("slice_setup_new_exec(mm=%p)\n", mm);
721
722 if (!is_32bit_task())
723 return;
724
725 mm_ctx_set_slb_addr_limit(&mm->context, DEFAULT_MAP_WINDOW);
726}
727#endif
728
729void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
730 unsigned long len, unsigned int psize)
731{
732 struct slice_mask mask;
733
734 VM_BUG_ON(radix_enabled());
735
736 slice_range_to_mask(start, len, &mask);
737 slice_convert(mm, &mask, psize);
738}
739
740#ifdef CONFIG_HUGETLB_PAGE
741/*
742 * is_hugepage_only_range() is used by generic code to verify whether
743 * a normal mmap mapping (non hugetlbfs) is valid on a given area.
744 *
745 * until the generic code provides a more generic hook and/or starts
746 * calling arch get_unmapped_area for MAP_FIXED (which our implementation
747 * here knows how to deal with), we hijack it to keep standard mappings
748 * away from us.
749 *
750 * because of that generic code limitation, MAP_FIXED mapping cannot
751 * "convert" back a slice with no VMAs to the standard page size, only
752 * get_unmapped_area() can. It would be possible to fix it here but I
753 * prefer working on fixing the generic code instead.
754 *
755 * WARNING: This will not work if hugetlbfs isn't enabled since the
756 * generic code will redefine that function as 0 in that. This is ok
757 * for now as we only use slices with hugetlbfs enabled. This should
758 * be fixed as the generic code gets fixed.
759 */
760int slice_is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
761 unsigned long len)
762{
763 const struct slice_mask *maskp;
764 unsigned int psize = mm_ctx_user_psize(&mm->context);
765
766 VM_BUG_ON(radix_enabled());
767
768 maskp = slice_mask_for_size(&mm->context, psize);
769
770 /* We need to account for 4k slices too */
771 if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) {
772 const struct slice_mask *compat_maskp;
773 struct slice_mask available;
774
775 compat_maskp = slice_mask_for_size(&mm->context, MMU_PAGE_4K);
776 slice_or_mask(&available, maskp, compat_maskp);
777 return !slice_check_range_fits(mm, &available, addr, len);
778 }
779
780 return !slice_check_range_fits(mm, maskp, addr, len);
781}
782#endif
1/*
2 * address space "slices" (meta-segments) support
3 *
4 * Copyright (C) 2007 Benjamin Herrenschmidt, IBM Corporation.
5 *
6 * Based on hugetlb implementation
7 *
8 * Copyright (C) 2003 David Gibson, IBM Corporation.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25#undef DEBUG
26
27#include <linux/kernel.h>
28#include <linux/mm.h>
29#include <linux/pagemap.h>
30#include <linux/err.h>
31#include <linux/spinlock.h>
32#include <linux/export.h>
33#include <linux/hugetlb.h>
34#include <asm/mman.h>
35#include <asm/mmu.h>
36#include <asm/copro.h>
37#include <asm/hugetlb.h>
38#include <asm/mmu_context.h>
39
40static DEFINE_SPINLOCK(slice_convert_lock);
41
42#ifdef DEBUG
43int _slice_debug = 1;
44
45static void slice_print_mask(const char *label, const struct slice_mask *mask)
46{
47 if (!_slice_debug)
48 return;
49 pr_devel("%s low_slice: %*pbl\n", label,
50 (int)SLICE_NUM_LOW, &mask->low_slices);
51 pr_devel("%s high_slice: %*pbl\n", label,
52 (int)SLICE_NUM_HIGH, mask->high_slices);
53}
54
55#define slice_dbg(fmt...) do { if (_slice_debug) pr_devel(fmt); } while (0)
56
57#else
58
59static void slice_print_mask(const char *label, const struct slice_mask *mask) {}
60#define slice_dbg(fmt...)
61
62#endif
63
64static void slice_range_to_mask(unsigned long start, unsigned long len,
65 struct slice_mask *ret)
66{
67 unsigned long end = start + len - 1;
68
69 ret->low_slices = 0;
70 if (SLICE_NUM_HIGH)
71 bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
72
73 if (start < SLICE_LOW_TOP) {
74 unsigned long mend = min(end,
75 (unsigned long)(SLICE_LOW_TOP - 1));
76
77 ret->low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
78 - (1u << GET_LOW_SLICE_INDEX(start));
79 }
80
81 if ((start + len) > SLICE_LOW_TOP) {
82 unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
83 unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
84 unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
85
86 bitmap_set(ret->high_slices, start_index, count);
87 }
88}
89
90static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
91 unsigned long len)
92{
93 struct vm_area_struct *vma;
94
95 if ((mm->context.slb_addr_limit - len) < addr)
96 return 0;
97 vma = find_vma(mm, addr);
98 return (!vma || (addr + len) <= vm_start_gap(vma));
99}
100
101static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice)
102{
103 return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT,
104 1ul << SLICE_LOW_SHIFT);
105}
106
107static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
108{
109 unsigned long start = slice << SLICE_HIGH_SHIFT;
110 unsigned long end = start + (1ul << SLICE_HIGH_SHIFT);
111
112#ifdef CONFIG_PPC64
113 /* Hack, so that each addresses is controlled by exactly one
114 * of the high or low area bitmaps, the first high area starts
115 * at 4GB, not 0 */
116 if (start == 0)
117 start = SLICE_LOW_TOP;
118#endif
119
120 return !slice_area_is_free(mm, start, end - start);
121}
122
123static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret,
124 unsigned long high_limit)
125{
126 unsigned long i;
127
128 ret->low_slices = 0;
129 if (SLICE_NUM_HIGH)
130 bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
131
132 for (i = 0; i < SLICE_NUM_LOW; i++)
133 if (!slice_low_has_vma(mm, i))
134 ret->low_slices |= 1u << i;
135
136 if (high_limit <= SLICE_LOW_TOP)
137 return;
138
139 for (i = 0; i < GET_HIGH_SLICE_INDEX(high_limit); i++)
140 if (!slice_high_has_vma(mm, i))
141 __set_bit(i, ret->high_slices);
142}
143
144#ifdef CONFIG_PPC_BOOK3S_64
145static struct slice_mask *slice_mask_for_size(struct mm_struct *mm, int psize)
146{
147#ifdef CONFIG_PPC_64K_PAGES
148 if (psize == MMU_PAGE_64K)
149 return &mm->context.mask_64k;
150#endif
151 if (psize == MMU_PAGE_4K)
152 return &mm->context.mask_4k;
153#ifdef CONFIG_HUGETLB_PAGE
154 if (psize == MMU_PAGE_16M)
155 return &mm->context.mask_16m;
156 if (psize == MMU_PAGE_16G)
157 return &mm->context.mask_16g;
158#endif
159 BUG();
160}
161#elif defined(CONFIG_PPC_8xx)
162static struct slice_mask *slice_mask_for_size(struct mm_struct *mm, int psize)
163{
164 if (psize == mmu_virtual_psize)
165 return &mm->context.mask_base_psize;
166#ifdef CONFIG_HUGETLB_PAGE
167 if (psize == MMU_PAGE_512K)
168 return &mm->context.mask_512k;
169 if (psize == MMU_PAGE_8M)
170 return &mm->context.mask_8m;
171#endif
172 BUG();
173}
174#else
175#error "Must define the slice masks for page sizes supported by the platform"
176#endif
177
178static bool slice_check_range_fits(struct mm_struct *mm,
179 const struct slice_mask *available,
180 unsigned long start, unsigned long len)
181{
182 unsigned long end = start + len - 1;
183 u64 low_slices = 0;
184
185 if (start < SLICE_LOW_TOP) {
186 unsigned long mend = min(end,
187 (unsigned long)(SLICE_LOW_TOP - 1));
188
189 low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
190 - (1u << GET_LOW_SLICE_INDEX(start));
191 }
192 if ((low_slices & available->low_slices) != low_slices)
193 return false;
194
195 if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) {
196 unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
197 unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
198 unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
199 unsigned long i;
200
201 for (i = start_index; i < start_index + count; i++) {
202 if (!test_bit(i, available->high_slices))
203 return false;
204 }
205 }
206
207 return true;
208}
209
210static void slice_flush_segments(void *parm)
211{
212#ifdef CONFIG_PPC64
213 struct mm_struct *mm = parm;
214 unsigned long flags;
215
216 if (mm != current->active_mm)
217 return;
218
219 copy_mm_to_paca(current->active_mm);
220
221 local_irq_save(flags);
222 slb_flush_and_rebolt();
223 local_irq_restore(flags);
224#endif
225}
226
227static void slice_convert(struct mm_struct *mm,
228 const struct slice_mask *mask, int psize)
229{
230 int index, mask_index;
231 /* Write the new slice psize bits */
232 unsigned char *hpsizes, *lpsizes;
233 struct slice_mask *psize_mask, *old_mask;
234 unsigned long i, flags;
235 int old_psize;
236
237 slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
238 slice_print_mask(" mask", mask);
239
240 psize_mask = slice_mask_for_size(mm, psize);
241
242 /* We need to use a spinlock here to protect against
243 * concurrent 64k -> 4k demotion ...
244 */
245 spin_lock_irqsave(&slice_convert_lock, flags);
246
247 lpsizes = mm->context.low_slices_psize;
248 for (i = 0; i < SLICE_NUM_LOW; i++) {
249 if (!(mask->low_slices & (1u << i)))
250 continue;
251
252 mask_index = i & 0x1;
253 index = i >> 1;
254
255 /* Update the slice_mask */
256 old_psize = (lpsizes[index] >> (mask_index * 4)) & 0xf;
257 old_mask = slice_mask_for_size(mm, old_psize);
258 old_mask->low_slices &= ~(1u << i);
259 psize_mask->low_slices |= 1u << i;
260
261 /* Update the sizes array */
262 lpsizes[index] = (lpsizes[index] & ~(0xf << (mask_index * 4))) |
263 (((unsigned long)psize) << (mask_index * 4));
264 }
265
266 hpsizes = mm->context.high_slices_psize;
267 for (i = 0; i < GET_HIGH_SLICE_INDEX(mm->context.slb_addr_limit); i++) {
268 if (!test_bit(i, mask->high_slices))
269 continue;
270
271 mask_index = i & 0x1;
272 index = i >> 1;
273
274 /* Update the slice_mask */
275 old_psize = (hpsizes[index] >> (mask_index * 4)) & 0xf;
276 old_mask = slice_mask_for_size(mm, old_psize);
277 __clear_bit(i, old_mask->high_slices);
278 __set_bit(i, psize_mask->high_slices);
279
280 /* Update the sizes array */
281 hpsizes[index] = (hpsizes[index] & ~(0xf << (mask_index * 4))) |
282 (((unsigned long)psize) << (mask_index * 4));
283 }
284
285 slice_dbg(" lsps=%lx, hsps=%lx\n",
286 (unsigned long)mm->context.low_slices_psize,
287 (unsigned long)mm->context.high_slices_psize);
288
289 spin_unlock_irqrestore(&slice_convert_lock, flags);
290
291 copro_flush_all_slbs(mm);
292}
293
294/*
295 * Compute which slice addr is part of;
296 * set *boundary_addr to the start or end boundary of that slice
297 * (depending on 'end' parameter);
298 * return boolean indicating if the slice is marked as available in the
299 * 'available' slice_mark.
300 */
301static bool slice_scan_available(unsigned long addr,
302 const struct slice_mask *available,
303 int end, unsigned long *boundary_addr)
304{
305 unsigned long slice;
306 if (addr < SLICE_LOW_TOP) {
307 slice = GET_LOW_SLICE_INDEX(addr);
308 *boundary_addr = (slice + end) << SLICE_LOW_SHIFT;
309 return !!(available->low_slices & (1u << slice));
310 } else {
311 slice = GET_HIGH_SLICE_INDEX(addr);
312 *boundary_addr = (slice + end) ?
313 ((slice + end) << SLICE_HIGH_SHIFT) : SLICE_LOW_TOP;
314 return !!test_bit(slice, available->high_slices);
315 }
316}
317
318static unsigned long slice_find_area_bottomup(struct mm_struct *mm,
319 unsigned long len,
320 const struct slice_mask *available,
321 int psize, unsigned long high_limit)
322{
323 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
324 unsigned long addr, found, next_end;
325 struct vm_unmapped_area_info info;
326
327 info.flags = 0;
328 info.length = len;
329 info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
330 info.align_offset = 0;
331
332 addr = TASK_UNMAPPED_BASE;
333 /*
334 * Check till the allow max value for this mmap request
335 */
336 while (addr < high_limit) {
337 info.low_limit = addr;
338 if (!slice_scan_available(addr, available, 1, &addr))
339 continue;
340
341 next_slice:
342 /*
343 * At this point [info.low_limit; addr) covers
344 * available slices only and ends at a slice boundary.
345 * Check if we need to reduce the range, or if we can
346 * extend it to cover the next available slice.
347 */
348 if (addr >= high_limit)
349 addr = high_limit;
350 else if (slice_scan_available(addr, available, 1, &next_end)) {
351 addr = next_end;
352 goto next_slice;
353 }
354 info.high_limit = addr;
355
356 found = vm_unmapped_area(&info);
357 if (!(found & ~PAGE_MASK))
358 return found;
359 }
360
361 return -ENOMEM;
362}
363
364static unsigned long slice_find_area_topdown(struct mm_struct *mm,
365 unsigned long len,
366 const struct slice_mask *available,
367 int psize, unsigned long high_limit)
368{
369 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
370 unsigned long addr, found, prev;
371 struct vm_unmapped_area_info info;
372
373 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
374 info.length = len;
375 info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
376 info.align_offset = 0;
377
378 addr = mm->mmap_base;
379 /*
380 * If we are trying to allocate above DEFAULT_MAP_WINDOW
381 * Add the different to the mmap_base.
382 * Only for that request for which high_limit is above
383 * DEFAULT_MAP_WINDOW we should apply this.
384 */
385 if (high_limit > DEFAULT_MAP_WINDOW)
386 addr += mm->context.slb_addr_limit - DEFAULT_MAP_WINDOW;
387
388 while (addr > PAGE_SIZE) {
389 info.high_limit = addr;
390 if (!slice_scan_available(addr - 1, available, 0, &addr))
391 continue;
392
393 prev_slice:
394 /*
395 * At this point [addr; info.high_limit) covers
396 * available slices only and starts at a slice boundary.
397 * Check if we need to reduce the range, or if we can
398 * extend it to cover the previous available slice.
399 */
400 if (addr < PAGE_SIZE)
401 addr = PAGE_SIZE;
402 else if (slice_scan_available(addr - 1, available, 0, &prev)) {
403 addr = prev;
404 goto prev_slice;
405 }
406 info.low_limit = addr;
407
408 found = vm_unmapped_area(&info);
409 if (!(found & ~PAGE_MASK))
410 return found;
411 }
412
413 /*
414 * A failed mmap() very likely causes application failure,
415 * so fall back to the bottom-up function here. This scenario
416 * can happen with large stack limits and large mmap()
417 * allocations.
418 */
419 return slice_find_area_bottomup(mm, len, available, psize, high_limit);
420}
421
422
423static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
424 const struct slice_mask *mask, int psize,
425 int topdown, unsigned long high_limit)
426{
427 if (topdown)
428 return slice_find_area_topdown(mm, len, mask, psize, high_limit);
429 else
430 return slice_find_area_bottomup(mm, len, mask, psize, high_limit);
431}
432
433static inline void slice_copy_mask(struct slice_mask *dst,
434 const struct slice_mask *src)
435{
436 dst->low_slices = src->low_slices;
437 if (!SLICE_NUM_HIGH)
438 return;
439 bitmap_copy(dst->high_slices, src->high_slices, SLICE_NUM_HIGH);
440}
441
442static inline void slice_or_mask(struct slice_mask *dst,
443 const struct slice_mask *src1,
444 const struct slice_mask *src2)
445{
446 dst->low_slices = src1->low_slices | src2->low_slices;
447 if (!SLICE_NUM_HIGH)
448 return;
449 bitmap_or(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
450}
451
452static inline void slice_andnot_mask(struct slice_mask *dst,
453 const struct slice_mask *src1,
454 const struct slice_mask *src2)
455{
456 dst->low_slices = src1->low_slices & ~src2->low_slices;
457 if (!SLICE_NUM_HIGH)
458 return;
459 bitmap_andnot(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
460}
461
462#ifdef CONFIG_PPC_64K_PAGES
463#define MMU_PAGE_BASE MMU_PAGE_64K
464#else
465#define MMU_PAGE_BASE MMU_PAGE_4K
466#endif
467
468unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
469 unsigned long flags, unsigned int psize,
470 int topdown)
471{
472 struct slice_mask good_mask;
473 struct slice_mask potential_mask;
474 const struct slice_mask *maskp;
475 const struct slice_mask *compat_maskp = NULL;
476 int fixed = (flags & MAP_FIXED);
477 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
478 unsigned long page_size = 1UL << pshift;
479 struct mm_struct *mm = current->mm;
480 unsigned long newaddr;
481 unsigned long high_limit;
482
483 high_limit = DEFAULT_MAP_WINDOW;
484 if (addr >= high_limit || (fixed && (addr + len > high_limit)))
485 high_limit = TASK_SIZE;
486
487 if (len > high_limit)
488 return -ENOMEM;
489 if (len & (page_size - 1))
490 return -EINVAL;
491 if (fixed) {
492 if (addr & (page_size - 1))
493 return -EINVAL;
494 if (addr > high_limit - len)
495 return -ENOMEM;
496 }
497
498 if (high_limit > mm->context.slb_addr_limit) {
499 /*
500 * Increasing the slb_addr_limit does not require
501 * slice mask cache to be recalculated because it should
502 * be already initialised beyond the old address limit.
503 */
504 mm->context.slb_addr_limit = high_limit;
505
506 on_each_cpu(slice_flush_segments, mm, 1);
507 }
508
509 /* Sanity checks */
510 BUG_ON(mm->task_size == 0);
511 BUG_ON(mm->context.slb_addr_limit == 0);
512 VM_BUG_ON(radix_enabled());
513
514 slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize);
515 slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n",
516 addr, len, flags, topdown);
517
518 /* If hint, make sure it matches our alignment restrictions */
519 if (!fixed && addr) {
520 addr = _ALIGN_UP(addr, page_size);
521 slice_dbg(" aligned addr=%lx\n", addr);
522 /* Ignore hint if it's too large or overlaps a VMA */
523 if (addr > high_limit - len ||
524 !slice_area_is_free(mm, addr, len))
525 addr = 0;
526 }
527
528 /* First make up a "good" mask of slices that have the right size
529 * already
530 */
531 maskp = slice_mask_for_size(mm, psize);
532
533 /*
534 * Here "good" means slices that are already the right page size,
535 * "compat" means slices that have a compatible page size (i.e.
536 * 4k in a 64k pagesize kernel), and "free" means slices without
537 * any VMAs.
538 *
539 * If MAP_FIXED:
540 * check if fits in good | compat => OK
541 * check if fits in good | compat | free => convert free
542 * else bad
543 * If have hint:
544 * check if hint fits in good => OK
545 * check if hint fits in good | free => convert free
546 * Otherwise:
547 * search in good, found => OK
548 * search in good | free, found => convert free
549 * search in good | compat | free, found => convert free.
550 */
551
552 /*
553 * If we support combo pages, we can allow 64k pages in 4k slices
554 * The mask copies could be avoided in most cases here if we had
555 * a pointer to good mask for the next code to use.
556 */
557 if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) {
558 compat_maskp = slice_mask_for_size(mm, MMU_PAGE_4K);
559 if (fixed)
560 slice_or_mask(&good_mask, maskp, compat_maskp);
561 else
562 slice_copy_mask(&good_mask, maskp);
563 } else {
564 slice_copy_mask(&good_mask, maskp);
565 }
566
567 slice_print_mask(" good_mask", &good_mask);
568 if (compat_maskp)
569 slice_print_mask(" compat_mask", compat_maskp);
570
571 /* First check hint if it's valid or if we have MAP_FIXED */
572 if (addr != 0 || fixed) {
573 /* Check if we fit in the good mask. If we do, we just return,
574 * nothing else to do
575 */
576 if (slice_check_range_fits(mm, &good_mask, addr, len)) {
577 slice_dbg(" fits good !\n");
578 newaddr = addr;
579 goto return_addr;
580 }
581 } else {
582 /* Now let's see if we can find something in the existing
583 * slices for that size
584 */
585 newaddr = slice_find_area(mm, len, &good_mask,
586 psize, topdown, high_limit);
587 if (newaddr != -ENOMEM) {
588 /* Found within the good mask, we don't have to setup,
589 * we thus return directly
590 */
591 slice_dbg(" found area at 0x%lx\n", newaddr);
592 goto return_addr;
593 }
594 }
595 /*
596 * We don't fit in the good mask, check what other slices are
597 * empty and thus can be converted
598 */
599 slice_mask_for_free(mm, &potential_mask, high_limit);
600 slice_or_mask(&potential_mask, &potential_mask, &good_mask);
601 slice_print_mask(" potential", &potential_mask);
602
603 if (addr != 0 || fixed) {
604 if (slice_check_range_fits(mm, &potential_mask, addr, len)) {
605 slice_dbg(" fits potential !\n");
606 newaddr = addr;
607 goto convert;
608 }
609 }
610
611 /* If we have MAP_FIXED and failed the above steps, then error out */
612 if (fixed)
613 return -EBUSY;
614
615 slice_dbg(" search...\n");
616
617 /* If we had a hint that didn't work out, see if we can fit
618 * anywhere in the good area.
619 */
620 if (addr) {
621 newaddr = slice_find_area(mm, len, &good_mask,
622 psize, topdown, high_limit);
623 if (newaddr != -ENOMEM) {
624 slice_dbg(" found area at 0x%lx\n", newaddr);
625 goto return_addr;
626 }
627 }
628
629 /* Now let's see if we can find something in the existing slices
630 * for that size plus free slices
631 */
632 newaddr = slice_find_area(mm, len, &potential_mask,
633 psize, topdown, high_limit);
634
635#ifdef CONFIG_PPC_64K_PAGES
636 if (newaddr == -ENOMEM && psize == MMU_PAGE_64K) {
637 /* retry the search with 4k-page slices included */
638 slice_or_mask(&potential_mask, &potential_mask, compat_maskp);
639 newaddr = slice_find_area(mm, len, &potential_mask,
640 psize, topdown, high_limit);
641 }
642#endif
643
644 if (newaddr == -ENOMEM)
645 return -ENOMEM;
646
647 slice_range_to_mask(newaddr, len, &potential_mask);
648 slice_dbg(" found potential area at 0x%lx\n", newaddr);
649 slice_print_mask(" mask", &potential_mask);
650
651 convert:
652 /*
653 * Try to allocate the context before we do slice convert
654 * so that we handle the context allocation failure gracefully.
655 */
656 if (need_extra_context(mm, newaddr)) {
657 if (alloc_extended_context(mm, newaddr) < 0)
658 return -ENOMEM;
659 }
660
661 slice_andnot_mask(&potential_mask, &potential_mask, &good_mask);
662 if (compat_maskp && !fixed)
663 slice_andnot_mask(&potential_mask, &potential_mask, compat_maskp);
664 if (potential_mask.low_slices ||
665 (SLICE_NUM_HIGH &&
666 !bitmap_empty(potential_mask.high_slices, SLICE_NUM_HIGH))) {
667 slice_convert(mm, &potential_mask, psize);
668 if (psize > MMU_PAGE_BASE)
669 on_each_cpu(slice_flush_segments, mm, 1);
670 }
671 return newaddr;
672
673return_addr:
674 if (need_extra_context(mm, newaddr)) {
675 if (alloc_extended_context(mm, newaddr) < 0)
676 return -ENOMEM;
677 }
678 return newaddr;
679}
680EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
681
682unsigned long arch_get_unmapped_area(struct file *filp,
683 unsigned long addr,
684 unsigned long len,
685 unsigned long pgoff,
686 unsigned long flags)
687{
688 return slice_get_unmapped_area(addr, len, flags,
689 current->mm->context.user_psize, 0);
690}
691
692unsigned long arch_get_unmapped_area_topdown(struct file *filp,
693 const unsigned long addr0,
694 const unsigned long len,
695 const unsigned long pgoff,
696 const unsigned long flags)
697{
698 return slice_get_unmapped_area(addr0, len, flags,
699 current->mm->context.user_psize, 1);
700}
701
702unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
703{
704 unsigned char *psizes;
705 int index, mask_index;
706
707 VM_BUG_ON(radix_enabled());
708
709 if (addr < SLICE_LOW_TOP) {
710 psizes = mm->context.low_slices_psize;
711 index = GET_LOW_SLICE_INDEX(addr);
712 } else {
713 psizes = mm->context.high_slices_psize;
714 index = GET_HIGH_SLICE_INDEX(addr);
715 }
716 mask_index = index & 0x1;
717 return (psizes[index >> 1] >> (mask_index * 4)) & 0xf;
718}
719EXPORT_SYMBOL_GPL(get_slice_psize);
720
721void slice_init_new_context_exec(struct mm_struct *mm)
722{
723 unsigned char *hpsizes, *lpsizes;
724 struct slice_mask *mask;
725 unsigned int psize = mmu_virtual_psize;
726
727 slice_dbg("slice_init_new_context_exec(mm=%p)\n", mm);
728
729 /*
730 * In the case of exec, use the default limit. In the
731 * case of fork it is just inherited from the mm being
732 * duplicated.
733 */
734#ifdef CONFIG_PPC64
735 mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW_USER64;
736#else
737 mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW;
738#endif
739
740 mm->context.user_psize = psize;
741
742 /*
743 * Set all slice psizes to the default.
744 */
745 lpsizes = mm->context.low_slices_psize;
746 memset(lpsizes, (psize << 4) | psize, SLICE_NUM_LOW >> 1);
747
748 hpsizes = mm->context.high_slices_psize;
749 memset(hpsizes, (psize << 4) | psize, SLICE_NUM_HIGH >> 1);
750
751 /*
752 * Slice mask cache starts zeroed, fill the default size cache.
753 */
754 mask = slice_mask_for_size(mm, psize);
755 mask->low_slices = ~0UL;
756 if (SLICE_NUM_HIGH)
757 bitmap_fill(mask->high_slices, SLICE_NUM_HIGH);
758}
759
760void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
761 unsigned long len, unsigned int psize)
762{
763 struct slice_mask mask;
764
765 VM_BUG_ON(radix_enabled());
766
767 slice_range_to_mask(start, len, &mask);
768 slice_convert(mm, &mask, psize);
769}
770
771#ifdef CONFIG_HUGETLB_PAGE
772/*
773 * is_hugepage_only_range() is used by generic code to verify whether
774 * a normal mmap mapping (non hugetlbfs) is valid on a given area.
775 *
776 * until the generic code provides a more generic hook and/or starts
777 * calling arch get_unmapped_area for MAP_FIXED (which our implementation
778 * here knows how to deal with), we hijack it to keep standard mappings
779 * away from us.
780 *
781 * because of that generic code limitation, MAP_FIXED mapping cannot
782 * "convert" back a slice with no VMAs to the standard page size, only
783 * get_unmapped_area() can. It would be possible to fix it here but I
784 * prefer working on fixing the generic code instead.
785 *
786 * WARNING: This will not work if hugetlbfs isn't enabled since the
787 * generic code will redefine that function as 0 in that. This is ok
788 * for now as we only use slices with hugetlbfs enabled. This should
789 * be fixed as the generic code gets fixed.
790 */
791int slice_is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
792 unsigned long len)
793{
794 const struct slice_mask *maskp;
795 unsigned int psize = mm->context.user_psize;
796
797 VM_BUG_ON(radix_enabled());
798
799 maskp = slice_mask_for_size(mm, psize);
800#ifdef CONFIG_PPC_64K_PAGES
801 /* We need to account for 4k slices too */
802 if (psize == MMU_PAGE_64K) {
803 const struct slice_mask *compat_maskp;
804 struct slice_mask available;
805
806 compat_maskp = slice_mask_for_size(mm, MMU_PAGE_4K);
807 slice_or_mask(&available, maskp, compat_maskp);
808 return !slice_check_range_fits(mm, &available, addr, len);
809 }
810#endif
811
812 return !slice_check_range_fits(mm, maskp, addr, len);
813}
814#endif