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 <asm/mman.h>
34 #include <asm/mmu.h>
35 #include <asm/spu.h>
36
37 static DEFINE_SPINLOCK(slice_convert_lock);
38
39
40 #ifdef DEBUG
41 int _slice_debug = 1;
42
slice_print_mask(const char * label,struct slice_mask mask)43 static void slice_print_mask(const char *label, struct slice_mask mask)
44 {
45 char *p, buf[16 + 3 + 16 + 1];
46 int i;
47
48 if (!_slice_debug)
49 return;
50 p = buf;
51 for (i = 0; i < SLICE_NUM_LOW; i++)
52 *(p++) = (mask.low_slices & (1 << i)) ? '1' : '0';
53 *(p++) = ' ';
54 *(p++) = '-';
55 *(p++) = ' ';
56 for (i = 0; i < SLICE_NUM_HIGH; i++)
57 *(p++) = (mask.high_slices & (1 << i)) ? '1' : '0';
58 *(p++) = 0;
59
60 printk(KERN_DEBUG "%s:%s\n", label, buf);
61 }
62
63 #define slice_dbg(fmt...) do { if (_slice_debug) pr_debug(fmt); } while(0)
64
65 #else
66
slice_print_mask(const char * label,struct slice_mask mask)67 static void slice_print_mask(const char *label, struct slice_mask mask) {}
68 #define slice_dbg(fmt...)
69
70 #endif
71
slice_range_to_mask(unsigned long start,unsigned long len)72 static struct slice_mask slice_range_to_mask(unsigned long start,
73 unsigned long len)
74 {
75 unsigned long end = start + len - 1;
76 struct slice_mask ret = { 0, 0 };
77
78 if (start < SLICE_LOW_TOP) {
79 unsigned long mend = min(end, SLICE_LOW_TOP);
80 unsigned long mstart = min(start, SLICE_LOW_TOP);
81
82 ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
83 - (1u << GET_LOW_SLICE_INDEX(mstart));
84 }
85
86 if ((start + len) > SLICE_LOW_TOP)
87 ret.high_slices = (1u << (GET_HIGH_SLICE_INDEX(end) + 1))
88 - (1u << GET_HIGH_SLICE_INDEX(start));
89
90 return ret;
91 }
92
slice_area_is_free(struct mm_struct * mm,unsigned long addr,unsigned long len)93 static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
94 unsigned long len)
95 {
96 struct vm_area_struct *vma;
97
98 if ((mm->task_size - len) < addr)
99 return 0;
100 vma = find_vma(mm, addr);
101 return (!vma || (addr + len) <= vma->vm_start);
102 }
103
slice_low_has_vma(struct mm_struct * mm,unsigned long slice)104 static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice)
105 {
106 return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT,
107 1ul << SLICE_LOW_SHIFT);
108 }
109
slice_high_has_vma(struct mm_struct * mm,unsigned long slice)110 static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
111 {
112 unsigned long start = slice << SLICE_HIGH_SHIFT;
113 unsigned long end = start + (1ul << SLICE_HIGH_SHIFT);
114
115 /* Hack, so that each addresses is controlled by exactly one
116 * of the high or low area bitmaps, the first high area starts
117 * at 4GB, not 0 */
118 if (start == 0)
119 start = SLICE_LOW_TOP;
120
121 return !slice_area_is_free(mm, start, end - start);
122 }
123
slice_mask_for_free(struct mm_struct * mm)124 static struct slice_mask slice_mask_for_free(struct mm_struct *mm)
125 {
126 struct slice_mask ret = { 0, 0 };
127 unsigned long i;
128
129 for (i = 0; i < SLICE_NUM_LOW; i++)
130 if (!slice_low_has_vma(mm, i))
131 ret.low_slices |= 1u << i;
132
133 if (mm->task_size <= SLICE_LOW_TOP)
134 return ret;
135
136 for (i = 0; i < SLICE_NUM_HIGH; i++)
137 if (!slice_high_has_vma(mm, i))
138 ret.high_slices |= 1u << i;
139
140 return ret;
141 }
142
slice_mask_for_size(struct mm_struct * mm,int psize)143 static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
144 {
145 struct slice_mask ret = { 0, 0 };
146 unsigned long i;
147 u64 psizes;
148
149 psizes = mm->context.low_slices_psize;
150 for (i = 0; i < SLICE_NUM_LOW; i++)
151 if (((psizes >> (i * 4)) & 0xf) == psize)
152 ret.low_slices |= 1u << i;
153
154 psizes = mm->context.high_slices_psize;
155 for (i = 0; i < SLICE_NUM_HIGH; i++)
156 if (((psizes >> (i * 4)) & 0xf) == psize)
157 ret.high_slices |= 1u << i;
158
159 return ret;
160 }
161
slice_check_fit(struct slice_mask mask,struct slice_mask available)162 static int slice_check_fit(struct slice_mask mask, struct slice_mask available)
163 {
164 return (mask.low_slices & available.low_slices) == mask.low_slices &&
165 (mask.high_slices & available.high_slices) == mask.high_slices;
166 }
167
slice_flush_segments(void * parm)168 static void slice_flush_segments(void *parm)
169 {
170 struct mm_struct *mm = parm;
171 unsigned long flags;
172
173 if (mm != current->active_mm)
174 return;
175
176 /* update the paca copy of the context struct */
177 get_paca()->context = current->active_mm->context;
178
179 local_irq_save(flags);
180 slb_flush_and_rebolt();
181 local_irq_restore(flags);
182 }
183
slice_convert(struct mm_struct * mm,struct slice_mask mask,int psize)184 static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psize)
185 {
186 /* Write the new slice psize bits */
187 u64 lpsizes, hpsizes;
188 unsigned long i, flags;
189
190 slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
191 slice_print_mask(" mask", mask);
192
193 /* We need to use a spinlock here to protect against
194 * concurrent 64k -> 4k demotion ...
195 */
196 spin_lock_irqsave(&slice_convert_lock, flags);
197
198 lpsizes = mm->context.low_slices_psize;
199 for (i = 0; i < SLICE_NUM_LOW; i++)
200 if (mask.low_slices & (1u << i))
201 lpsizes = (lpsizes & ~(0xful << (i * 4))) |
202 (((unsigned long)psize) << (i * 4));
203
204 hpsizes = mm->context.high_slices_psize;
205 for (i = 0; i < SLICE_NUM_HIGH; i++)
206 if (mask.high_slices & (1u << i))
207 hpsizes = (hpsizes & ~(0xful << (i * 4))) |
208 (((unsigned long)psize) << (i * 4));
209
210 mm->context.low_slices_psize = lpsizes;
211 mm->context.high_slices_psize = hpsizes;
212
213 slice_dbg(" lsps=%lx, hsps=%lx\n",
214 mm->context.low_slices_psize,
215 mm->context.high_slices_psize);
216
217 spin_unlock_irqrestore(&slice_convert_lock, flags);
218
219 #ifdef CONFIG_SPU_BASE
220 spu_flush_all_slbs(mm);
221 #endif
222 }
223
slice_find_area_bottomup(struct mm_struct * mm,unsigned long len,struct slice_mask available,int psize,int use_cache)224 static unsigned long slice_find_area_bottomup(struct mm_struct *mm,
225 unsigned long len,
226 struct slice_mask available,
227 int psize, int use_cache)
228 {
229 struct vm_area_struct *vma;
230 unsigned long start_addr, addr;
231 struct slice_mask mask;
232 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
233
234 if (use_cache) {
235 if (len <= mm->cached_hole_size) {
236 start_addr = addr = TASK_UNMAPPED_BASE;
237 mm->cached_hole_size = 0;
238 } else
239 start_addr = addr = mm->free_area_cache;
240 } else
241 start_addr = addr = TASK_UNMAPPED_BASE;
242
243 full_search:
244 for (;;) {
245 addr = _ALIGN_UP(addr, 1ul << pshift);
246 if ((TASK_SIZE - len) < addr)
247 break;
248 vma = find_vma(mm, addr);
249 BUG_ON(vma && (addr >= vma->vm_end));
250
251 mask = slice_range_to_mask(addr, len);
252 if (!slice_check_fit(mask, available)) {
253 if (addr < SLICE_LOW_TOP)
254 addr = _ALIGN_UP(addr + 1, 1ul << SLICE_LOW_SHIFT);
255 else
256 addr = _ALIGN_UP(addr + 1, 1ul << SLICE_HIGH_SHIFT);
257 continue;
258 }
259 if (!vma || addr + len <= vma->vm_start) {
260 /*
261 * Remember the place where we stopped the search:
262 */
263 if (use_cache)
264 mm->free_area_cache = addr + len;
265 return addr;
266 }
267 if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start)
268 mm->cached_hole_size = vma->vm_start - addr;
269 addr = vma->vm_end;
270 }
271
272 /* Make sure we didn't miss any holes */
273 if (use_cache && start_addr != TASK_UNMAPPED_BASE) {
274 start_addr = addr = TASK_UNMAPPED_BASE;
275 mm->cached_hole_size = 0;
276 goto full_search;
277 }
278 return -ENOMEM;
279 }
280
slice_find_area_topdown(struct mm_struct * mm,unsigned long len,struct slice_mask available,int psize,int use_cache)281 static unsigned long slice_find_area_topdown(struct mm_struct *mm,
282 unsigned long len,
283 struct slice_mask available,
284 int psize, int use_cache)
285 {
286 struct vm_area_struct *vma;
287 unsigned long addr;
288 struct slice_mask mask;
289 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
290
291 /* check if free_area_cache is useful for us */
292 if (use_cache) {
293 if (len <= mm->cached_hole_size) {
294 mm->cached_hole_size = 0;
295 mm->free_area_cache = mm->mmap_base;
296 }
297
298 /* either no address requested or can't fit in requested
299 * address hole
300 */
301 addr = mm->free_area_cache;
302
303 /* make sure it can fit in the remaining address space */
304 if (addr > len) {
305 addr = _ALIGN_DOWN(addr - len, 1ul << pshift);
306 mask = slice_range_to_mask(addr, len);
307 if (slice_check_fit(mask, available) &&
308 slice_area_is_free(mm, addr, len))
309 /* remember the address as a hint for
310 * next time
311 */
312 return (mm->free_area_cache = addr);
313 }
314 }
315
316 addr = mm->mmap_base;
317 while (addr > len) {
318 /* Go down by chunk size */
319 addr = _ALIGN_DOWN(addr - len, 1ul << pshift);
320
321 /* Check for hit with different page size */
322 mask = slice_range_to_mask(addr, len);
323 if (!slice_check_fit(mask, available)) {
324 if (addr < SLICE_LOW_TOP)
325 addr = _ALIGN_DOWN(addr, 1ul << SLICE_LOW_SHIFT);
326 else if (addr < (1ul << SLICE_HIGH_SHIFT))
327 addr = SLICE_LOW_TOP;
328 else
329 addr = _ALIGN_DOWN(addr, 1ul << SLICE_HIGH_SHIFT);
330 continue;
331 }
332
333 /*
334 * Lookup failure means no vma is above this address,
335 * else if new region fits below vma->vm_start,
336 * return with success:
337 */
338 vma = find_vma(mm, addr);
339 if (!vma || (addr + len) <= vma->vm_start) {
340 /* remember the address as a hint for next time */
341 if (use_cache)
342 mm->free_area_cache = addr;
343 return addr;
344 }
345
346 /* remember the largest hole we saw so far */
347 if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start)
348 mm->cached_hole_size = vma->vm_start - addr;
349
350 /* try just below the current vma->vm_start */
351 addr = vma->vm_start;
352 }
353
354 /*
355 * A failed mmap() very likely causes application failure,
356 * so fall back to the bottom-up function here. This scenario
357 * can happen with large stack limits and large mmap()
358 * allocations.
359 */
360 addr = slice_find_area_bottomup(mm, len, available, psize, 0);
361
362 /*
363 * Restore the topdown base:
364 */
365 if (use_cache) {
366 mm->free_area_cache = mm->mmap_base;
367 mm->cached_hole_size = ~0UL;
368 }
369
370 return addr;
371 }
372
373
slice_find_area(struct mm_struct * mm,unsigned long len,struct slice_mask mask,int psize,int topdown,int use_cache)374 static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
375 struct slice_mask mask, int psize,
376 int topdown, int use_cache)
377 {
378 if (topdown)
379 return slice_find_area_topdown(mm, len, mask, psize, use_cache);
380 else
381 return slice_find_area_bottomup(mm, len, mask, psize, use_cache);
382 }
383
384 #define or_mask(dst, src) do { \
385 (dst).low_slices |= (src).low_slices; \
386 (dst).high_slices |= (src).high_slices; \
387 } while (0)
388
389 #define andnot_mask(dst, src) do { \
390 (dst).low_slices &= ~(src).low_slices; \
391 (dst).high_slices &= ~(src).high_slices; \
392 } while (0)
393
394 #ifdef CONFIG_PPC_64K_PAGES
395 #define MMU_PAGE_BASE MMU_PAGE_64K
396 #else
397 #define MMU_PAGE_BASE MMU_PAGE_4K
398 #endif
399
slice_get_unmapped_area(unsigned long addr,unsigned long len,unsigned long flags,unsigned int psize,int topdown,int use_cache)400 unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
401 unsigned long flags, unsigned int psize,
402 int topdown, int use_cache)
403 {
404 struct slice_mask mask = {0, 0};
405 struct slice_mask good_mask;
406 struct slice_mask potential_mask = {0,0} /* silence stupid warning */;
407 struct slice_mask compat_mask = {0, 0};
408 int fixed = (flags & MAP_FIXED);
409 int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
410 struct mm_struct *mm = current->mm;
411 unsigned long newaddr;
412
413 /* Sanity checks */
414 BUG_ON(mm->task_size == 0);
415
416 slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize);
417 slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d, use_cache=%d\n",
418 addr, len, flags, topdown, use_cache);
419
420 if (len > mm->task_size)
421 return -ENOMEM;
422 if (len & ((1ul << pshift) - 1))
423 return -EINVAL;
424 if (fixed && (addr & ((1ul << pshift) - 1)))
425 return -EINVAL;
426 if (fixed && addr > (mm->task_size - len))
427 return -EINVAL;
428
429 /* If hint, make sure it matches our alignment restrictions */
430 if (!fixed && addr) {
431 addr = _ALIGN_UP(addr, 1ul << pshift);
432 slice_dbg(" aligned addr=%lx\n", addr);
433 /* Ignore hint if it's too large or overlaps a VMA */
434 if (addr > mm->task_size - len ||
435 !slice_area_is_free(mm, addr, len))
436 addr = 0;
437 }
438
439 /* First make up a "good" mask of slices that have the right size
440 * already
441 */
442 good_mask = slice_mask_for_size(mm, psize);
443 slice_print_mask(" good_mask", good_mask);
444
445 /*
446 * Here "good" means slices that are already the right page size,
447 * "compat" means slices that have a compatible page size (i.e.
448 * 4k in a 64k pagesize kernel), and "free" means slices without
449 * any VMAs.
450 *
451 * If MAP_FIXED:
452 * check if fits in good | compat => OK
453 * check if fits in good | compat | free => convert free
454 * else bad
455 * If have hint:
456 * check if hint fits in good => OK
457 * check if hint fits in good | free => convert free
458 * Otherwise:
459 * search in good, found => OK
460 * search in good | free, found => convert free
461 * search in good | compat | free, found => convert free.
462 */
463
464 #ifdef CONFIG_PPC_64K_PAGES
465 /* If we support combo pages, we can allow 64k pages in 4k slices */
466 if (psize == MMU_PAGE_64K) {
467 compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K);
468 if (fixed)
469 or_mask(good_mask, compat_mask);
470 }
471 #endif
472
473 /* First check hint if it's valid or if we have MAP_FIXED */
474 if (addr != 0 || fixed) {
475 /* Build a mask for the requested range */
476 mask = slice_range_to_mask(addr, len);
477 slice_print_mask(" mask", mask);
478
479 /* Check if we fit in the good mask. If we do, we just return,
480 * nothing else to do
481 */
482 if (slice_check_fit(mask, good_mask)) {
483 slice_dbg(" fits good !\n");
484 return addr;
485 }
486 } else {
487 /* Now let's see if we can find something in the existing
488 * slices for that size
489 */
490 newaddr = slice_find_area(mm, len, good_mask, psize, topdown,
491 use_cache);
492 if (newaddr != -ENOMEM) {
493 /* Found within the good mask, we don't have to setup,
494 * we thus return directly
495 */
496 slice_dbg(" found area at 0x%lx\n", newaddr);
497 return newaddr;
498 }
499 }
500
501 /* We don't fit in the good mask, check what other slices are
502 * empty and thus can be converted
503 */
504 potential_mask = slice_mask_for_free(mm);
505 or_mask(potential_mask, good_mask);
506 slice_print_mask(" potential", potential_mask);
507
508 if ((addr != 0 || fixed) && slice_check_fit(mask, potential_mask)) {
509 slice_dbg(" fits potential !\n");
510 goto convert;
511 }
512
513 /* If we have MAP_FIXED and failed the above steps, then error out */
514 if (fixed)
515 return -EBUSY;
516
517 slice_dbg(" search...\n");
518
519 /* If we had a hint that didn't work out, see if we can fit
520 * anywhere in the good area.
521 */
522 if (addr) {
523 addr = slice_find_area(mm, len, good_mask, psize, topdown,
524 use_cache);
525 if (addr != -ENOMEM) {
526 slice_dbg(" found area at 0x%lx\n", addr);
527 return addr;
528 }
529 }
530
531 /* Now let's see if we can find something in the existing slices
532 * for that size plus free slices
533 */
534 addr = slice_find_area(mm, len, potential_mask, psize, topdown,
535 use_cache);
536
537 #ifdef CONFIG_PPC_64K_PAGES
538 if (addr == -ENOMEM && psize == MMU_PAGE_64K) {
539 /* retry the search with 4k-page slices included */
540 or_mask(potential_mask, compat_mask);
541 addr = slice_find_area(mm, len, potential_mask, psize,
542 topdown, use_cache);
543 }
544 #endif
545
546 if (addr == -ENOMEM)
547 return -ENOMEM;
548
549 mask = slice_range_to_mask(addr, len);
550 slice_dbg(" found potential area at 0x%lx\n", addr);
551 slice_print_mask(" mask", mask);
552
553 convert:
554 andnot_mask(mask, good_mask);
555 andnot_mask(mask, compat_mask);
556 if (mask.low_slices || mask.high_slices) {
557 slice_convert(mm, mask, psize);
558 if (psize > MMU_PAGE_BASE)
559 on_each_cpu(slice_flush_segments, mm, 1);
560 }
561 return addr;
562
563 }
564 EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
565
arch_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)566 unsigned long arch_get_unmapped_area(struct file *filp,
567 unsigned long addr,
568 unsigned long len,
569 unsigned long pgoff,
570 unsigned long flags)
571 {
572 return slice_get_unmapped_area(addr, len, flags,
573 current->mm->context.user_psize,
574 0, 1);
575 }
576
arch_get_unmapped_area_topdown(struct file * filp,const unsigned long addr0,const unsigned long len,const unsigned long pgoff,const unsigned long flags)577 unsigned long arch_get_unmapped_area_topdown(struct file *filp,
578 const unsigned long addr0,
579 const unsigned long len,
580 const unsigned long pgoff,
581 const unsigned long flags)
582 {
583 return slice_get_unmapped_area(addr0, len, flags,
584 current->mm->context.user_psize,
585 1, 1);
586 }
587
get_slice_psize(struct mm_struct * mm,unsigned long addr)588 unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
589 {
590 u64 psizes;
591 int index;
592
593 if (addr < SLICE_LOW_TOP) {
594 psizes = mm->context.low_slices_psize;
595 index = GET_LOW_SLICE_INDEX(addr);
596 } else {
597 psizes = mm->context.high_slices_psize;
598 index = GET_HIGH_SLICE_INDEX(addr);
599 }
600
601 return (psizes >> (index * 4)) & 0xf;
602 }
603 EXPORT_SYMBOL_GPL(get_slice_psize);
604
605 /*
606 * This is called by hash_page when it needs to do a lazy conversion of
607 * an address space from real 64K pages to combo 4K pages (typically
608 * when hitting a non cacheable mapping on a processor or hypervisor
609 * that won't allow them for 64K pages).
610 *
611 * This is also called in init_new_context() to change back the user
612 * psize from whatever the parent context had it set to
613 * N.B. This may be called before mm->context.id has been set.
614 *
615 * This function will only change the content of the {low,high)_slice_psize
616 * masks, it will not flush SLBs as this shall be handled lazily by the
617 * caller.
618 */
slice_set_user_psize(struct mm_struct * mm,unsigned int psize)619 void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
620 {
621 unsigned long flags, lpsizes, hpsizes;
622 unsigned int old_psize;
623 int i;
624
625 slice_dbg("slice_set_user_psize(mm=%p, psize=%d)\n", mm, psize);
626
627 spin_lock_irqsave(&slice_convert_lock, flags);
628
629 old_psize = mm->context.user_psize;
630 slice_dbg(" old_psize=%d\n", old_psize);
631 if (old_psize == psize)
632 goto bail;
633
634 mm->context.user_psize = psize;
635 wmb();
636
637 lpsizes = mm->context.low_slices_psize;
638 for (i = 0; i < SLICE_NUM_LOW; i++)
639 if (((lpsizes >> (i * 4)) & 0xf) == old_psize)
640 lpsizes = (lpsizes & ~(0xful << (i * 4))) |
641 (((unsigned long)psize) << (i * 4));
642
643 hpsizes = mm->context.high_slices_psize;
644 for (i = 0; i < SLICE_NUM_HIGH; i++)
645 if (((hpsizes >> (i * 4)) & 0xf) == old_psize)
646 hpsizes = (hpsizes & ~(0xful << (i * 4))) |
647 (((unsigned long)psize) << (i * 4));
648
649 mm->context.low_slices_psize = lpsizes;
650 mm->context.high_slices_psize = hpsizes;
651
652 slice_dbg(" lsps=%lx, hsps=%lx\n",
653 mm->context.low_slices_psize,
654 mm->context.high_slices_psize);
655
656 bail:
657 spin_unlock_irqrestore(&slice_convert_lock, flags);
658 }
659
slice_set_psize(struct mm_struct * mm,unsigned long address,unsigned int psize)660 void slice_set_psize(struct mm_struct *mm, unsigned long address,
661 unsigned int psize)
662 {
663 unsigned long i, flags;
664 u64 *p;
665
666 spin_lock_irqsave(&slice_convert_lock, flags);
667 if (address < SLICE_LOW_TOP) {
668 i = GET_LOW_SLICE_INDEX(address);
669 p = &mm->context.low_slices_psize;
670 } else {
671 i = GET_HIGH_SLICE_INDEX(address);
672 p = &mm->context.high_slices_psize;
673 }
674 *p = (*p & ~(0xful << (i * 4))) | ((unsigned long) psize << (i * 4));
675 spin_unlock_irqrestore(&slice_convert_lock, flags);
676
677 #ifdef CONFIG_SPU_BASE
678 spu_flush_all_slbs(mm);
679 #endif
680 }
681
slice_set_range_psize(struct mm_struct * mm,unsigned long start,unsigned long len,unsigned int psize)682 void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
683 unsigned long len, unsigned int psize)
684 {
685 struct slice_mask mask = slice_range_to_mask(start, len);
686
687 slice_convert(mm, mask, psize);
688 }
689
690 /*
691 * is_hugepage_only_range() is used by generic code to verify wether
692 * a normal mmap mapping (non hugetlbfs) is valid on a given area.
693 *
694 * until the generic code provides a more generic hook and/or starts
695 * calling arch get_unmapped_area for MAP_FIXED (which our implementation
696 * here knows how to deal with), we hijack it to keep standard mappings
697 * away from us.
698 *
699 * because of that generic code limitation, MAP_FIXED mapping cannot
700 * "convert" back a slice with no VMAs to the standard page size, only
701 * get_unmapped_area() can. It would be possible to fix it here but I
702 * prefer working on fixing the generic code instead.
703 *
704 * WARNING: This will not work if hugetlbfs isn't enabled since the
705 * generic code will redefine that function as 0 in that. This is ok
706 * for now as we only use slices with hugetlbfs enabled. This should
707 * be fixed as the generic code gets fixed.
708 */
is_hugepage_only_range(struct mm_struct * mm,unsigned long addr,unsigned long len)709 int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
710 unsigned long len)
711 {
712 struct slice_mask mask, available;
713 unsigned int psize = mm->context.user_psize;
714
715 mask = slice_range_to_mask(addr, len);
716 available = slice_mask_for_size(mm, psize);
717 #ifdef CONFIG_PPC_64K_PAGES
718 /* We need to account for 4k slices too */
719 if (psize == MMU_PAGE_64K) {
720 struct slice_mask compat_mask;
721 compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K);
722 or_mask(available, compat_mask);
723 }
724 #endif
725
726 #if 0 /* too verbose */
727 slice_dbg("is_hugepage_only_range(mm=%p, addr=%lx, len=%lx)\n",
728 mm, addr, len);
729 slice_print_mask(" mask", mask);
730 slice_print_mask(" available", available);
731 #endif
732 return !slice_check_fit(mask, available);
733 }
734
735