~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/powerpc/mm/slice.c

Version: ~ [ linux-5.1-rc5 ] ~ [ linux-5.0.7 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.34 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.111 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.168 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.178 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.138 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.65 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 <linux/sched/mm.h>
 35 #include <linux/security.h>
 36 #include <asm/mman.h>
 37 #include <asm/mmu.h>
 38 #include <asm/copro.h>
 39 #include <asm/hugetlb.h>
 40 #include <asm/mmu_context.h>
 41 
 42 static DEFINE_SPINLOCK(slice_convert_lock);
 43 
 44 #ifdef DEBUG
 45 int _slice_debug = 1;
 46 
 47 static void slice_print_mask(const char *label, const struct slice_mask *mask)
 48 {
 49         if (!_slice_debug)
 50                 return;
 51         pr_devel("%s low_slice: %*pbl\n", label,
 52                         (int)SLICE_NUM_LOW, &mask->low_slices);
 53         pr_devel("%s high_slice: %*pbl\n", label,
 54                         (int)SLICE_NUM_HIGH, mask->high_slices);
 55 }
 56 
 57 #define slice_dbg(fmt...) do { if (_slice_debug) pr_devel(fmt); } while (0)
 58 
 59 #else
 60 
 61 static void slice_print_mask(const char *label, const struct slice_mask *mask) {}
 62 #define slice_dbg(fmt...)
 63 
 64 #endif
 65 
 66 static inline bool slice_addr_is_low(unsigned long addr)
 67 {
 68         u64 tmp = (u64)addr;
 69 
 70         return tmp < SLICE_LOW_TOP;
 71 }
 72 
 73 static void slice_range_to_mask(unsigned long start, unsigned long len,
 74                                 struct slice_mask *ret)
 75 {
 76         unsigned long end = start + len - 1;
 77 
 78         ret->low_slices = 0;
 79         if (SLICE_NUM_HIGH)
 80                 bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
 81 
 82         if (slice_addr_is_low(start)) {
 83                 unsigned long mend = min(end,
 84                                          (unsigned long)(SLICE_LOW_TOP - 1));
 85 
 86                 ret->low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
 87                         - (1u << GET_LOW_SLICE_INDEX(start));
 88         }
 89 
 90         if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) {
 91                 unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
 92                 unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
 93                 unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
 94 
 95                 bitmap_set(ret->high_slices, start_index, count);
 96         }
 97 }
 98 
 99 static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
100                               unsigned long len)
101 {
102         struct vm_area_struct *vma;
103 
104         if ((mm->context.slb_addr_limit - len) < addr)
105                 return 0;
106         vma = find_vma(mm, addr);
107         return (!vma || (addr + len) <= vm_start_gap(vma));
108 }
109 
110 static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice)
111 {
112         return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT,
113                                    1ul << SLICE_LOW_SHIFT);
114 }
115 
116 static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
117 {
118         unsigned long start = slice << SLICE_HIGH_SHIFT;
119         unsigned long end = start + (1ul << SLICE_HIGH_SHIFT);
120 
121 #ifdef CONFIG_PPC64
122         /* Hack, so that each addresses is controlled by exactly one
123          * of the high or low area bitmaps, the first high area starts
124          * at 4GB, not 0 */
125         if (start == 0)
126                 start = SLICE_LOW_TOP;
127 #endif
128 
129         return !slice_area_is_free(mm, start, end - start);
130 }
131 
132 static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret,
133                                 unsigned long high_limit)
134 {
135         unsigned long i;
136 
137         ret->low_slices = 0;
138         if (SLICE_NUM_HIGH)
139                 bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
140 
141         for (i = 0; i < SLICE_NUM_LOW; i++)
142                 if (!slice_low_has_vma(mm, i))
143                         ret->low_slices |= 1u << i;
144 
145         if (slice_addr_is_low(high_limit - 1))
146                 return;
147 
148         for (i = 0; i < GET_HIGH_SLICE_INDEX(high_limit); i++)
149                 if (!slice_high_has_vma(mm, i))
150                         __set_bit(i, ret->high_slices);
151 }
152 
153 #ifdef CONFIG_PPC_BOOK3S_64
154 static struct slice_mask *slice_mask_for_size(struct mm_struct *mm, int psize)
155 {
156 #ifdef CONFIG_PPC_64K_PAGES
157         if (psize == MMU_PAGE_64K)
158                 return &mm->context.mask_64k;
159 #endif
160         if (psize == MMU_PAGE_4K)
161                 return &mm->context.mask_4k;
162 #ifdef CONFIG_HUGETLB_PAGE
163         if (psize == MMU_PAGE_16M)
164                 return &mm->context.mask_16m;
165         if (psize == MMU_PAGE_16G)
166                 return &mm->context.mask_16g;
167 #endif
168         BUG();
169 }
170 #elif defined(CONFIG_PPC_8xx)
171 static struct slice_mask *slice_mask_for_size(struct mm_struct *mm, int psize)
172 {
173         if (psize == mmu_virtual_psize)
174                 return &mm->context.mask_base_psize;
175 #ifdef CONFIG_HUGETLB_PAGE
176         if (psize == MMU_PAGE_512K)
177                 return &mm->context.mask_512k;
178         if (psize == MMU_PAGE_8M)
179                 return &mm->context.mask_8m;
180 #endif
181         BUG();
182 }
183 #else
184 #error "Must define the slice masks for page sizes supported by the platform"
185 #endif
186 
187 static bool slice_check_range_fits(struct mm_struct *mm,
188                            const struct slice_mask *available,
189                            unsigned long start, unsigned long len)
190 {
191         unsigned long end = start + len - 1;
192         u64 low_slices = 0;
193 
194         if (slice_addr_is_low(start)) {
195                 unsigned long mend = min(end,
196                                          (unsigned long)(SLICE_LOW_TOP - 1));
197 
198                 low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
199                                 - (1u << GET_LOW_SLICE_INDEX(start));
200         }
201         if ((low_slices & available->low_slices) != low_slices)
202                 return false;
203 
204         if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) {
205                 unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
206                 unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
207                 unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
208                 unsigned long i;
209 
210                 for (i = start_index; i < start_index + count; i++) {
211                         if (!test_bit(i, available->high_slices))
212                                 return false;
213                 }
214         }
215 
216         return true;
217 }
218 
219 static void slice_flush_segments(void *parm)
220 {
221 #ifdef CONFIG_PPC64
222         struct mm_struct *mm = parm;
223         unsigned long flags;
224 
225         if (mm != current->active_mm)
226                 return;
227 
228         copy_mm_to_paca(current->active_mm);
229 
230         local_irq_save(flags);
231         slb_flush_and_restore_bolted();
232         local_irq_restore(flags);
233 #endif
234 }
235 
236 static void slice_convert(struct mm_struct *mm,
237                                 const struct slice_mask *mask, int psize)
238 {
239         int index, mask_index;
240         /* Write the new slice psize bits */
241         unsigned char *hpsizes, *lpsizes;
242         struct slice_mask *psize_mask, *old_mask;
243         unsigned long i, flags;
244         int old_psize;
245 
246         slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
247         slice_print_mask(" mask", mask);
248 
249         psize_mask = slice_mask_for_size(mm, psize);
250 
251         /* We need to use a spinlock here to protect against
252          * concurrent 64k -> 4k demotion ...
253          */
254         spin_lock_irqsave(&slice_convert_lock, flags);
255 
256         lpsizes = mm->context.low_slices_psize;
257         for (i = 0; i < SLICE_NUM_LOW; i++) {
258                 if (!(mask->low_slices & (1u << i)))
259                         continue;
260 
261                 mask_index = i & 0x1;
262                 index = i >> 1;
263 
264                 /* Update the slice_mask */
265                 old_psize = (lpsizes[index] >> (mask_index * 4)) & 0xf;
266                 old_mask = slice_mask_for_size(mm, old_psize);
267                 old_mask->low_slices &= ~(1u << i);
268                 psize_mask->low_slices |= 1u << i;
269 
270                 /* Update the sizes array */
271                 lpsizes[index] = (lpsizes[index] & ~(0xf << (mask_index * 4))) |
272                                 (((unsigned long)psize) << (mask_index * 4));
273         }
274 
275         hpsizes = mm->context.high_slices_psize;
276         for (i = 0; i < GET_HIGH_SLICE_INDEX(mm->context.slb_addr_limit); i++) {
277                 if (!test_bit(i, mask->high_slices))
278                         continue;
279 
280                 mask_index = i & 0x1;
281                 index = i >> 1;
282 
283                 /* Update the slice_mask */
284                 old_psize = (hpsizes[index] >> (mask_index * 4)) & 0xf;
285                 old_mask = slice_mask_for_size(mm, old_psize);
286                 __clear_bit(i, old_mask->high_slices);
287                 __set_bit(i, psize_mask->high_slices);
288 
289                 /* Update the sizes array */
290                 hpsizes[index] = (hpsizes[index] & ~(0xf << (mask_index * 4))) |
291                                 (((unsigned long)psize) << (mask_index * 4));
292         }
293 
294         slice_dbg(" lsps=%lx, hsps=%lx\n",
295                   (unsigned long)mm->context.low_slices_psize,
296                   (unsigned long)mm->context.high_slices_psize);
297 
298         spin_unlock_irqrestore(&slice_convert_lock, flags);
299 
300         copro_flush_all_slbs(mm);
301 }
302 
303 /*
304  * Compute which slice addr is part of;
305  * set *boundary_addr to the start or end boundary of that slice
306  * (depending on 'end' parameter);
307  * return boolean indicating if the slice is marked as available in the
308  * 'available' slice_mark.
309  */
310 static bool slice_scan_available(unsigned long addr,
311                                  const struct slice_mask *available,
312                                  int end, unsigned long *boundary_addr)
313 {
314         unsigned long slice;
315         if (slice_addr_is_low(addr)) {
316                 slice = GET_LOW_SLICE_INDEX(addr);
317                 *boundary_addr = (slice + end) << SLICE_LOW_SHIFT;
318                 return !!(available->low_slices & (1u << slice));
319         } else {
320                 slice = GET_HIGH_SLICE_INDEX(addr);
321                 *boundary_addr = (slice + end) ?
322                         ((slice + end) << SLICE_HIGH_SHIFT) : SLICE_LOW_TOP;
323                 return !!test_bit(slice, available->high_slices);
324         }
325 }
326 
327 static unsigned long slice_find_area_bottomup(struct mm_struct *mm,
328                                               unsigned long len,
329                                               const struct slice_mask *available,
330                                               int psize, unsigned long high_limit)
331 {
332         int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
333         unsigned long addr, found, next_end;
334         struct vm_unmapped_area_info info;
335 
336         info.flags = 0;
337         info.length = len;
338         info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
339         info.align_offset = 0;
340 
341         addr = TASK_UNMAPPED_BASE;
342         /*
343          * Check till the allow max value for this mmap request
344          */
345         while (addr < high_limit) {
346                 info.low_limit = addr;
347                 if (!slice_scan_available(addr, available, 1, &addr))
348                         continue;
349 
350  next_slice:
351                 /*
352                  * At this point [info.low_limit; addr) covers
353                  * available slices only and ends at a slice boundary.
354                  * Check if we need to reduce the range, or if we can
355                  * extend it to cover the next available slice.
356                  */
357                 if (addr >= high_limit)
358                         addr = high_limit;
359                 else if (slice_scan_available(addr, available, 1, &next_end)) {
360                         addr = next_end;
361                         goto next_slice;
362                 }
363                 info.high_limit = addr;
364 
365                 found = vm_unmapped_area(&info);
366                 if (!(found & ~PAGE_MASK))
367                         return found;
368         }
369 
370         return -ENOMEM;
371 }
372 
373 static unsigned long slice_find_area_topdown(struct mm_struct *mm,
374                                              unsigned long len,
375                                              const struct slice_mask *available,
376                                              int psize, unsigned long high_limit)
377 {
378         int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
379         unsigned long addr, found, prev;
380         struct vm_unmapped_area_info info;
381         unsigned long min_addr = max(PAGE_SIZE, mmap_min_addr);
382 
383         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
384         info.length = len;
385         info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
386         info.align_offset = 0;
387 
388         addr = mm->mmap_base;
389         /*
390          * If we are trying to allocate above DEFAULT_MAP_WINDOW
391          * Add the different to the mmap_base.
392          * Only for that request for which high_limit is above
393          * DEFAULT_MAP_WINDOW we should apply this.
394          */
395         if (high_limit > DEFAULT_MAP_WINDOW)
396                 addr += mm->context.slb_addr_limit - DEFAULT_MAP_WINDOW;
397 
398         while (addr > min_addr) {
399                 info.high_limit = addr;
400                 if (!slice_scan_available(addr - 1, available, 0, &addr))
401                         continue;
402 
403  prev_slice:
404                 /*
405                  * At this point [addr; info.high_limit) covers
406                  * available slices only and starts at a slice boundary.
407                  * Check if we need to reduce the range, or if we can
408                  * extend it to cover the previous available slice.
409                  */
410                 if (addr < min_addr)
411                         addr = min_addr;
412                 else if (slice_scan_available(addr - 1, available, 0, &prev)) {
413                         addr = prev;
414                         goto prev_slice;
415                 }
416                 info.low_limit = addr;
417 
418                 found = vm_unmapped_area(&info);
419                 if (!(found & ~PAGE_MASK))
420                         return found;
421         }
422 
423         /*
424          * A failed mmap() very likely causes application failure,
425          * so fall back to the bottom-up function here. This scenario
426          * can happen with large stack limits and large mmap()
427          * allocations.
428          */
429         return slice_find_area_bottomup(mm, len, available, psize, high_limit);
430 }
431 
432 
433 static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
434                                      const struct slice_mask *mask, int psize,
435                                      int topdown, unsigned long high_limit)
436 {
437         if (topdown)
438                 return slice_find_area_topdown(mm, len, mask, psize, high_limit);
439         else
440                 return slice_find_area_bottomup(mm, len, mask, psize, high_limit);
441 }
442 
443 static inline void slice_copy_mask(struct slice_mask *dst,
444                                         const struct slice_mask *src)
445 {
446         dst->low_slices = src->low_slices;
447         if (!SLICE_NUM_HIGH)
448                 return;
449         bitmap_copy(dst->high_slices, src->high_slices, SLICE_NUM_HIGH);
450 }
451 
452 static inline void slice_or_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_or(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
460 }
461 
462 static inline void slice_andnot_mask(struct slice_mask *dst,
463                                         const struct slice_mask *src1,
464                                         const struct slice_mask *src2)
465 {
466         dst->low_slices = src1->low_slices & ~src2->low_slices;
467         if (!SLICE_NUM_HIGH)
468                 return;
469         bitmap_andnot(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
470 }
471 
472 #ifdef CONFIG_PPC_64K_PAGES
473 #define MMU_PAGE_BASE   MMU_PAGE_64K
474 #else
475 #define MMU_PAGE_BASE   MMU_PAGE_4K
476 #endif
477 
478 unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
479                                       unsigned long flags, unsigned int psize,
480                                       int topdown)
481 {
482         struct slice_mask good_mask;
483         struct slice_mask potential_mask;
484         const struct slice_mask *maskp;
485         const struct slice_mask *compat_maskp = NULL;
486         int fixed = (flags & MAP_FIXED);
487         int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
488         unsigned long page_size = 1UL << pshift;
489         struct mm_struct *mm = current->mm;
490         unsigned long newaddr;
491         unsigned long high_limit;
492 
493         high_limit = DEFAULT_MAP_WINDOW;
494         if (addr >= high_limit || (fixed && (addr + len > high_limit)))
495                 high_limit = TASK_SIZE;
496 
497         if (len > high_limit)
498                 return -ENOMEM;
499         if (len & (page_size - 1))
500                 return -EINVAL;
501         if (fixed) {
502                 if (addr & (page_size - 1))
503                         return -EINVAL;
504                 if (addr > high_limit - len)
505                         return -ENOMEM;
506         }
507 
508         if (high_limit > mm->context.slb_addr_limit) {
509                 /*
510                  * Increasing the slb_addr_limit does not require
511                  * slice mask cache to be recalculated because it should
512                  * be already initialised beyond the old address limit.
513                  */
514                 mm->context.slb_addr_limit = high_limit;
515 
516                 on_each_cpu(slice_flush_segments, mm, 1);
517         }
518 
519         /* Sanity checks */
520         BUG_ON(mm->task_size == 0);
521         BUG_ON(mm->context.slb_addr_limit == 0);
522         VM_BUG_ON(radix_enabled());
523 
524         slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize);
525         slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n",
526                   addr, len, flags, topdown);
527 
528         /* If hint, make sure it matches our alignment restrictions */
529         if (!fixed && addr) {
530                 addr = _ALIGN_UP(addr, page_size);
531                 slice_dbg(" aligned addr=%lx\n", addr);
532                 /* Ignore hint if it's too large or overlaps a VMA */
533                 if (addr > high_limit - len || addr < mmap_min_addr ||
534                     !slice_area_is_free(mm, addr, len))
535                         addr = 0;
536         }
537 
538         /* First make up a "good" mask of slices that have the right size
539          * already
540          */
541         maskp = slice_mask_for_size(mm, psize);
542 
543         /*
544          * Here "good" means slices that are already the right page size,
545          * "compat" means slices that have a compatible page size (i.e.
546          * 4k in a 64k pagesize kernel), and "free" means slices without
547          * any VMAs.
548          *
549          * If MAP_FIXED:
550          *      check if fits in good | compat => OK
551          *      check if fits in good | compat | free => convert free
552          *      else bad
553          * If have hint:
554          *      check if hint fits in good => OK
555          *      check if hint fits in good | free => convert free
556          * Otherwise:
557          *      search in good, found => OK
558          *      search in good | free, found => convert free
559          *      search in good | compat | free, found => convert free.
560          */
561 
562         /*
563          * If we support combo pages, we can allow 64k pages in 4k slices
564          * The mask copies could be avoided in most cases here if we had
565          * a pointer to good mask for the next code to use.
566          */
567         if (IS_ENABLED(CONFIG_PPC_64K_PAGES) && psize == MMU_PAGE_64K) {
568                 compat_maskp = slice_mask_for_size(mm, MMU_PAGE_4K);
569                 if (fixed)
570                         slice_or_mask(&good_mask, maskp, compat_maskp);
571                 else
572                         slice_copy_mask(&good_mask, maskp);
573         } else {
574                 slice_copy_mask(&good_mask, maskp);
575         }
576 
577         slice_print_mask(" good_mask", &good_mask);
578         if (compat_maskp)
579                 slice_print_mask(" compat_mask", compat_maskp);
580 
581         /* First check hint if it's valid or if we have MAP_FIXED */
582         if (addr != 0 || fixed) {
583                 /* Check if we fit in the good mask. If we do, we just return,
584                  * nothing else to do
585                  */
586                 if (slice_check_range_fits(mm, &good_mask, addr, len)) {
587                         slice_dbg(" fits good !\n");
588                         newaddr = addr;
589                         goto return_addr;
590                 }
591         } else {
592                 /* Now let's see if we can find something in the existing
593                  * slices for that size
594                  */
595                 newaddr = slice_find_area(mm, len, &good_mask,
596                                           psize, topdown, high_limit);
597                 if (newaddr != -ENOMEM) {
598                         /* Found within the good mask, we don't have to setup,
599                          * we thus return directly
600                          */
601                         slice_dbg(" found area at 0x%lx\n", newaddr);
602                         goto return_addr;
603                 }
604         }
605         /*
606          * We don't fit in the good mask, check what other slices are
607          * empty and thus can be converted
608          */
609         slice_mask_for_free(mm, &potential_mask, high_limit);
610         slice_or_mask(&potential_mask, &potential_mask, &good_mask);
611         slice_print_mask(" potential", &potential_mask);
612 
613         if (addr != 0 || fixed) {
614                 if (slice_check_range_fits(mm, &potential_mask, addr, len)) {
615                         slice_dbg(" fits potential !\n");
616                         newaddr = addr;
617                         goto convert;
618                 }
619         }
620 
621         /* If we have MAP_FIXED and failed the above steps, then error out */
622         if (fixed)
623                 return -EBUSY;
624 
625         slice_dbg(" search...\n");
626 
627         /* If we had a hint that didn't work out, see if we can fit
628          * anywhere in the good area.
629          */
630         if (addr) {
631                 newaddr = slice_find_area(mm, len, &good_mask,
632                                           psize, topdown, high_limit);
633                 if (newaddr != -ENOMEM) {
634                         slice_dbg(" found area at 0x%lx\n", newaddr);
635                         goto return_addr;
636                 }
637         }
638 
639         /* Now let's see if we can find something in the existing slices
640          * for that size plus free slices
641          */
642         newaddr = slice_find_area(mm, len, &potential_mask,
643                                   psize, topdown, high_limit);
644 
645 #ifdef CONFIG_PPC_64K_PAGES
646         if (newaddr == -ENOMEM && psize == MMU_PAGE_64K) {
647                 /* retry the search with 4k-page slices included */
648                 slice_or_mask(&potential_mask, &potential_mask, compat_maskp);
649                 newaddr = slice_find_area(mm, len, &potential_mask,
650                                           psize, topdown, high_limit);
651         }
652 #endif
653 
654         if (newaddr == -ENOMEM)
655                 return -ENOMEM;
656 
657         slice_range_to_mask(newaddr, len, &potential_mask);
658         slice_dbg(" found potential area at 0x%lx\n", newaddr);
659         slice_print_mask(" mask", &potential_mask);
660 
661  convert:
662         /*
663          * Try to allocate the context before we do slice convert
664          * so that we handle the context allocation failure gracefully.
665          */
666         if (need_extra_context(mm, newaddr)) {
667                 if (alloc_extended_context(mm, newaddr) < 0)
668                         return -ENOMEM;
669         }
670 
671         slice_andnot_mask(&potential_mask, &potential_mask, &good_mask);
672         if (compat_maskp && !fixed)
673                 slice_andnot_mask(&potential_mask, &potential_mask, compat_maskp);
674         if (potential_mask.low_slices ||
675                 (SLICE_NUM_HIGH &&
676                  !bitmap_empty(potential_mask.high_slices, SLICE_NUM_HIGH))) {
677                 slice_convert(mm, &potential_mask, psize);
678                 if (psize > MMU_PAGE_BASE)
679                         on_each_cpu(slice_flush_segments, mm, 1);
680         }
681         return newaddr;
682 
683 return_addr:
684         if (need_extra_context(mm, newaddr)) {
685                 if (alloc_extended_context(mm, newaddr) < 0)
686                         return -ENOMEM;
687         }
688         return newaddr;
689 }
690 EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
691 
692 unsigned long arch_get_unmapped_area(struct file *filp,
693                                      unsigned long addr,
694                                      unsigned long len,
695                                      unsigned long pgoff,
696                                      unsigned long flags)
697 {
698         return slice_get_unmapped_area(addr, len, flags,
699                                        current->mm->context.user_psize, 0);
700 }
701 
702 unsigned long arch_get_unmapped_area_topdown(struct file *filp,
703                                              const unsigned long addr0,
704                                              const unsigned long len,
705                                              const unsigned long pgoff,
706                                              const unsigned long flags)
707 {
708         return slice_get_unmapped_area(addr0, len, flags,
709                                        current->mm->context.user_psize, 1);
710 }
711 
712 unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
713 {
714         unsigned char *psizes;
715         int index, mask_index;
716 
717         VM_BUG_ON(radix_enabled());
718 
719         if (slice_addr_is_low(addr)) {
720                 psizes = mm->context.low_slices_psize;
721                 index = GET_LOW_SLICE_INDEX(addr);
722         } else {
723                 psizes = mm->context.high_slices_psize;
724                 index = GET_HIGH_SLICE_INDEX(addr);
725         }
726         mask_index = index & 0x1;
727         return (psizes[index >> 1] >> (mask_index * 4)) & 0xf;
728 }
729 EXPORT_SYMBOL_GPL(get_slice_psize);
730 
731 void slice_init_new_context_exec(struct mm_struct *mm)
732 {
733         unsigned char *hpsizes, *lpsizes;
734         struct slice_mask *mask;
735         unsigned int psize = mmu_virtual_psize;
736 
737         slice_dbg("slice_init_new_context_exec(mm=%p)\n", mm);
738 
739         /*
740          * In the case of exec, use the default limit. In the
741          * case of fork it is just inherited from the mm being
742          * duplicated.
743          */
744 #ifdef CONFIG_PPC64
745         mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW_USER64;
746 #else
747         mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW;
748 #endif
749 
750         mm->context.user_psize = psize;
751 
752         /*
753          * Set all slice psizes to the default.
754          */
755         lpsizes = mm->context.low_slices_psize;
756         memset(lpsizes, (psize << 4) | psize, SLICE_NUM_LOW >> 1);
757 
758         hpsizes = mm->context.high_slices_psize;
759         memset(hpsizes, (psize << 4) | psize, SLICE_NUM_HIGH >> 1);
760 
761         /*
762          * Slice mask cache starts zeroed, fill the default size cache.
763          */
764         mask = slice_mask_for_size(mm, psize);
765         mask->low_slices = ~0UL;
766         if (SLICE_NUM_HIGH)
767                 bitmap_fill(mask->high_slices, SLICE_NUM_HIGH);
768 }
769 
770 #ifdef CONFIG_PPC_BOOK3S_64
771 void slice_setup_new_exec(void)
772 {
773         struct mm_struct *mm = current->mm;
774 
775         slice_dbg("slice_setup_new_exec(mm=%p)\n", mm);
776 
777         if (!is_32bit_task())
778                 return;
779 
780         mm->context.slb_addr_limit = DEFAULT_MAP_WINDOW;
781 }
782 #endif
783 
784 void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
785                            unsigned long len, unsigned int psize)
786 {
787         struct slice_mask mask;
788 
789         VM_BUG_ON(radix_enabled());
790 
791         slice_range_to_mask(start, len, &mask);
792         slice_convert(mm, &mask, psize);
793 }
794 
795 #ifdef CONFIG_HUGETLB_PAGE
796 /*
797  * is_hugepage_only_range() is used by generic code to verify whether
798  * a normal mmap mapping (non hugetlbfs) is valid on a given area.
799  *
800  * until the generic code provides a more generic hook and/or starts
801  * calling arch get_unmapped_area for MAP_FIXED (which our implementation
802  * here knows how to deal with), we hijack it to keep standard mappings
803  * away from us.
804  *
805  * because of that generic code limitation, MAP_FIXED mapping cannot
806  * "convert" back a slice with no VMAs to the standard page size, only
807  * get_unmapped_area() can. It would be possible to fix it here but I
808  * prefer working on fixing the generic code instead.
809  *
810  * WARNING: This will not work if hugetlbfs isn't enabled since the
811  * generic code will redefine that function as 0 in that. This is ok
812  * for now as we only use slices with hugetlbfs enabled. This should
813  * be fixed as the generic code gets fixed.
814  */
815 int slice_is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
816                            unsigned long len)
817 {
818         const struct slice_mask *maskp;
819         unsigned int psize = mm->context.user_psize;
820 
821         VM_BUG_ON(radix_enabled());
822 
823         maskp = slice_mask_for_size(mm, psize);
824 #ifdef CONFIG_PPC_64K_PAGES
825         /* We need to account for 4k slices too */
826         if (psize == MMU_PAGE_64K) {
827                 const struct slice_mask *compat_maskp;
828                 struct slice_mask available;
829 
830                 compat_maskp = slice_mask_for_size(mm, MMU_PAGE_4K);
831                 slice_or_mask(&available, maskp, compat_maskp);
832                 return !slice_check_range_fits(mm, &available, addr, len);
833         }
834 #endif
835 
836         return !slice_check_range_fits(mm, maskp, addr, len);
837 }
838 #endif
839 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp