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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/module.h> | |
33 | #include <asm/mman.h> | |
34 | #include <asm/mmu.h> | |
35 | #include <asm/spu.h> | |
36 | ||
37 | static spinlock_t slice_convert_lock = SPIN_LOCK_UNLOCKED; | |
38 | ||
39 | ||
40 | #ifdef DEBUG | |
41 | int _slice_debug = 1; | |
42 | ||
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 | ||
67 | static void slice_print_mask(const char *label, struct slice_mask mask) {} | |
68 | #define slice_dbg(fmt...) | |
69 | ||
70 | #endif | |
71 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | mb(); | |
219 | ||
220 | /* XXX this is sub-optimal but will do for now */ | |
221 | on_each_cpu(slice_flush_segments, mm, 0, 1); | |
222 | #ifdef CONFIG_SPU_BASE | |
223 | spu_flush_all_slbs(mm); | |
224 | #endif | |
225 | } | |
226 | ||
227 | static unsigned long slice_find_area_bottomup(struct mm_struct *mm, | |
228 | unsigned long len, | |
229 | struct slice_mask available, | |
230 | int psize, int use_cache) | |
231 | { | |
232 | struct vm_area_struct *vma; | |
233 | unsigned long start_addr, addr; | |
234 | struct slice_mask mask; | |
235 | int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); | |
236 | ||
237 | if (use_cache) { | |
238 | if (len <= mm->cached_hole_size) { | |
239 | start_addr = addr = TASK_UNMAPPED_BASE; | |
240 | mm->cached_hole_size = 0; | |
241 | } else | |
242 | start_addr = addr = mm->free_area_cache; | |
243 | } else | |
244 | start_addr = addr = TASK_UNMAPPED_BASE; | |
245 | ||
246 | full_search: | |
247 | for (;;) { | |
248 | addr = _ALIGN_UP(addr, 1ul << pshift); | |
249 | if ((TASK_SIZE - len) < addr) | |
250 | break; | |
251 | vma = find_vma(mm, addr); | |
252 | BUG_ON(vma && (addr >= vma->vm_end)); | |
253 | ||
254 | mask = slice_range_to_mask(addr, len); | |
255 | if (!slice_check_fit(mask, available)) { | |
256 | if (addr < SLICE_LOW_TOP) | |
257 | addr = _ALIGN_UP(addr + 1, 1ul << SLICE_LOW_SHIFT); | |
258 | else | |
259 | addr = _ALIGN_UP(addr + 1, 1ul << SLICE_HIGH_SHIFT); | |
260 | continue; | |
261 | } | |
262 | if (!vma || addr + len <= vma->vm_start) { | |
263 | /* | |
264 | * Remember the place where we stopped the search: | |
265 | */ | |
266 | if (use_cache) | |
267 | mm->free_area_cache = addr + len; | |
268 | return addr; | |
269 | } | |
270 | if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start) | |
271 | mm->cached_hole_size = vma->vm_start - addr; | |
272 | addr = vma->vm_end; | |
273 | } | |
274 | ||
275 | /* Make sure we didn't miss any holes */ | |
276 | if (use_cache && start_addr != TASK_UNMAPPED_BASE) { | |
277 | start_addr = addr = TASK_UNMAPPED_BASE; | |
278 | mm->cached_hole_size = 0; | |
279 | goto full_search; | |
280 | } | |
281 | return -ENOMEM; | |
282 | } | |
283 | ||
284 | static unsigned long slice_find_area_topdown(struct mm_struct *mm, | |
285 | unsigned long len, | |
286 | struct slice_mask available, | |
287 | int psize, int use_cache) | |
288 | { | |
289 | struct vm_area_struct *vma; | |
290 | unsigned long addr; | |
291 | struct slice_mask mask; | |
292 | int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); | |
293 | ||
294 | /* check if free_area_cache is useful for us */ | |
295 | if (use_cache) { | |
296 | if (len <= mm->cached_hole_size) { | |
297 | mm->cached_hole_size = 0; | |
298 | mm->free_area_cache = mm->mmap_base; | |
299 | } | |
300 | ||
301 | /* either no address requested or can't fit in requested | |
302 | * address hole | |
303 | */ | |
304 | addr = mm->free_area_cache; | |
305 | ||
306 | /* make sure it can fit in the remaining address space */ | |
307 | if (addr > len) { | |
308 | addr = _ALIGN_DOWN(addr - len, 1ul << pshift); | |
309 | mask = slice_range_to_mask(addr, len); | |
310 | if (slice_check_fit(mask, available) && | |
311 | slice_area_is_free(mm, addr, len)) | |
312 | /* remember the address as a hint for | |
313 | * next time | |
314 | */ | |
315 | return (mm->free_area_cache = addr); | |
316 | } | |
317 | } | |
318 | ||
319 | addr = mm->mmap_base; | |
320 | while (addr > len) { | |
321 | /* Go down by chunk size */ | |
322 | addr = _ALIGN_DOWN(addr - len, 1ul << pshift); | |
323 | ||
324 | /* Check for hit with different page size */ | |
325 | mask = slice_range_to_mask(addr, len); | |
326 | if (!slice_check_fit(mask, available)) { | |
327 | if (addr < SLICE_LOW_TOP) | |
328 | addr = _ALIGN_DOWN(addr, 1ul << SLICE_LOW_SHIFT); | |
329 | else if (addr < (1ul << SLICE_HIGH_SHIFT)) | |
330 | addr = SLICE_LOW_TOP; | |
331 | else | |
332 | addr = _ALIGN_DOWN(addr, 1ul << SLICE_HIGH_SHIFT); | |
333 | continue; | |
334 | } | |
335 | ||
336 | /* | |
337 | * Lookup failure means no vma is above this address, | |
338 | * else if new region fits below vma->vm_start, | |
339 | * return with success: | |
340 | */ | |
341 | vma = find_vma(mm, addr); | |
342 | if (!vma || (addr + len) <= vma->vm_start) { | |
343 | /* remember the address as a hint for next time */ | |
344 | if (use_cache) | |
345 | mm->free_area_cache = addr; | |
346 | return addr; | |
347 | } | |
348 | ||
349 | /* remember the largest hole we saw so far */ | |
350 | if (use_cache && (addr + mm->cached_hole_size) < vma->vm_start) | |
351 | mm->cached_hole_size = vma->vm_start - addr; | |
352 | ||
353 | /* try just below the current vma->vm_start */ | |
354 | addr = vma->vm_start; | |
355 | } | |
356 | ||
357 | /* | |
358 | * A failed mmap() very likely causes application failure, | |
359 | * so fall back to the bottom-up function here. This scenario | |
360 | * can happen with large stack limits and large mmap() | |
361 | * allocations. | |
362 | */ | |
363 | addr = slice_find_area_bottomup(mm, len, available, psize, 0); | |
364 | ||
365 | /* | |
366 | * Restore the topdown base: | |
367 | */ | |
368 | if (use_cache) { | |
369 | mm->free_area_cache = mm->mmap_base; | |
370 | mm->cached_hole_size = ~0UL; | |
371 | } | |
372 | ||
373 | return addr; | |
374 | } | |
375 | ||
376 | ||
377 | static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len, | |
378 | struct slice_mask mask, int psize, | |
379 | int topdown, int use_cache) | |
380 | { | |
381 | if (topdown) | |
382 | return slice_find_area_topdown(mm, len, mask, psize, use_cache); | |
383 | else | |
384 | return slice_find_area_bottomup(mm, len, mask, psize, use_cache); | |
385 | } | |
386 | ||
387 | unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len, | |
388 | unsigned long flags, unsigned int psize, | |
389 | int topdown, int use_cache) | |
390 | { | |
391 | struct slice_mask mask; | |
392 | struct slice_mask good_mask; | |
393 | struct slice_mask potential_mask = {0,0} /* silence stupid warning */; | |
394 | int pmask_set = 0; | |
395 | int fixed = (flags & MAP_FIXED); | |
396 | int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); | |
397 | struct mm_struct *mm = current->mm; | |
398 | ||
399 | /* Sanity checks */ | |
400 | BUG_ON(mm->task_size == 0); | |
401 | ||
402 | slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize); | |
403 | slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d, use_cache=%d\n", | |
404 | addr, len, flags, topdown, use_cache); | |
405 | ||
406 | if (len > mm->task_size) | |
407 | return -ENOMEM; | |
d1f5a77f BH |
408 | if (len & ((1ul << pshift) - 1)) |
409 | return -EINVAL; | |
d0f13e3c BH |
410 | if (fixed && (addr & ((1ul << pshift) - 1))) |
411 | return -EINVAL; | |
412 | if (fixed && addr > (mm->task_size - len)) | |
413 | return -EINVAL; | |
414 | ||
415 | /* If hint, make sure it matches our alignment restrictions */ | |
416 | if (!fixed && addr) { | |
417 | addr = _ALIGN_UP(addr, 1ul << pshift); | |
418 | slice_dbg(" aligned addr=%lx\n", addr); | |
419 | } | |
420 | ||
421 | /* First makeup a "good" mask of slices that have the right size | |
422 | * already | |
423 | */ | |
424 | good_mask = slice_mask_for_size(mm, psize); | |
425 | slice_print_mask(" good_mask", good_mask); | |
426 | ||
427 | /* First check hint if it's valid or if we have MAP_FIXED */ | |
428 | if ((addr != 0 || fixed) && (mm->task_size - len) >= addr) { | |
429 | ||
430 | /* Don't bother with hint if it overlaps a VMA */ | |
431 | if (!fixed && !slice_area_is_free(mm, addr, len)) | |
432 | goto search; | |
433 | ||
434 | /* Build a mask for the requested range */ | |
435 | mask = slice_range_to_mask(addr, len); | |
436 | slice_print_mask(" mask", mask); | |
437 | ||
438 | /* Check if we fit in the good mask. If we do, we just return, | |
439 | * nothing else to do | |
440 | */ | |
441 | if (slice_check_fit(mask, good_mask)) { | |
442 | slice_dbg(" fits good !\n"); | |
443 | return addr; | |
444 | } | |
445 | ||
446 | /* We don't fit in the good mask, check what other slices are | |
447 | * empty and thus can be converted | |
448 | */ | |
449 | potential_mask = slice_mask_for_free(mm); | |
450 | potential_mask.low_slices |= good_mask.low_slices; | |
451 | potential_mask.high_slices |= good_mask.high_slices; | |
452 | pmask_set = 1; | |
453 | slice_print_mask(" potential", potential_mask); | |
454 | if (slice_check_fit(mask, potential_mask)) { | |
455 | slice_dbg(" fits potential !\n"); | |
456 | goto convert; | |
457 | } | |
458 | } | |
459 | ||
460 | /* If we have MAP_FIXED and failed the above step, then error out */ | |
461 | if (fixed) | |
462 | return -EBUSY; | |
463 | ||
464 | search: | |
465 | slice_dbg(" search...\n"); | |
466 | ||
467 | /* Now let's see if we can find something in the existing slices | |
468 | * for that size | |
469 | */ | |
470 | addr = slice_find_area(mm, len, good_mask, psize, topdown, use_cache); | |
471 | if (addr != -ENOMEM) { | |
472 | /* Found within the good mask, we don't have to setup, | |
473 | * we thus return directly | |
474 | */ | |
475 | slice_dbg(" found area at 0x%lx\n", addr); | |
476 | return addr; | |
477 | } | |
478 | ||
479 | /* Won't fit, check what can be converted */ | |
480 | if (!pmask_set) { | |
481 | potential_mask = slice_mask_for_free(mm); | |
482 | potential_mask.low_slices |= good_mask.low_slices; | |
483 | potential_mask.high_slices |= good_mask.high_slices; | |
484 | pmask_set = 1; | |
485 | slice_print_mask(" potential", potential_mask); | |
486 | } | |
487 | ||
488 | /* Now let's see if we can find something in the existing slices | |
489 | * for that size | |
490 | */ | |
491 | addr = slice_find_area(mm, len, potential_mask, psize, topdown, | |
492 | use_cache); | |
493 | if (addr == -ENOMEM) | |
494 | return -ENOMEM; | |
495 | ||
496 | mask = slice_range_to_mask(addr, len); | |
497 | slice_dbg(" found potential area at 0x%lx\n", addr); | |
498 | slice_print_mask(" mask", mask); | |
499 | ||
500 | convert: | |
501 | slice_convert(mm, mask, psize); | |
502 | return addr; | |
503 | ||
504 | } | |
505 | EXPORT_SYMBOL_GPL(slice_get_unmapped_area); | |
506 | ||
507 | unsigned long arch_get_unmapped_area(struct file *filp, | |
508 | unsigned long addr, | |
509 | unsigned long len, | |
510 | unsigned long pgoff, | |
511 | unsigned long flags) | |
512 | { | |
513 | return slice_get_unmapped_area(addr, len, flags, | |
514 | current->mm->context.user_psize, | |
515 | 0, 1); | |
516 | } | |
517 | ||
518 | unsigned long arch_get_unmapped_area_topdown(struct file *filp, | |
519 | const unsigned long addr0, | |
520 | const unsigned long len, | |
521 | const unsigned long pgoff, | |
522 | const unsigned long flags) | |
523 | { | |
524 | return slice_get_unmapped_area(addr0, len, flags, | |
525 | current->mm->context.user_psize, | |
526 | 1, 1); | |
527 | } | |
528 | ||
529 | unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr) | |
530 | { | |
531 | u64 psizes; | |
532 | int index; | |
533 | ||
534 | if (addr < SLICE_LOW_TOP) { | |
535 | psizes = mm->context.low_slices_psize; | |
536 | index = GET_LOW_SLICE_INDEX(addr); | |
537 | } else { | |
538 | psizes = mm->context.high_slices_psize; | |
539 | index = GET_HIGH_SLICE_INDEX(addr); | |
540 | } | |
541 | ||
542 | return (psizes >> (index * 4)) & 0xf; | |
543 | } | |
544 | EXPORT_SYMBOL_GPL(get_slice_psize); | |
545 | ||
546 | /* | |
547 | * This is called by hash_page when it needs to do a lazy conversion of | |
548 | * an address space from real 64K pages to combo 4K pages (typically | |
549 | * when hitting a non cacheable mapping on a processor or hypervisor | |
550 | * that won't allow them for 64K pages). | |
551 | * | |
552 | * This is also called in init_new_context() to change back the user | |
553 | * psize from whatever the parent context had it set to | |
9dfe5c53 | 554 | * N.B. This may be called before mm->context.id has been set. |
d0f13e3c BH |
555 | * |
556 | * This function will only change the content of the {low,high)_slice_psize | |
557 | * masks, it will not flush SLBs as this shall be handled lazily by the | |
558 | * caller. | |
559 | */ | |
560 | void slice_set_user_psize(struct mm_struct *mm, unsigned int psize) | |
561 | { | |
562 | unsigned long flags, lpsizes, hpsizes; | |
563 | unsigned int old_psize; | |
564 | int i; | |
565 | ||
566 | slice_dbg("slice_set_user_psize(mm=%p, psize=%d)\n", mm, psize); | |
567 | ||
568 | spin_lock_irqsave(&slice_convert_lock, flags); | |
569 | ||
570 | old_psize = mm->context.user_psize; | |
571 | slice_dbg(" old_psize=%d\n", old_psize); | |
572 | if (old_psize == psize) | |
573 | goto bail; | |
574 | ||
575 | mm->context.user_psize = psize; | |
576 | wmb(); | |
577 | ||
578 | lpsizes = mm->context.low_slices_psize; | |
579 | for (i = 0; i < SLICE_NUM_LOW; i++) | |
580 | if (((lpsizes >> (i * 4)) & 0xf) == old_psize) | |
581 | lpsizes = (lpsizes & ~(0xful << (i * 4))) | | |
582 | (((unsigned long)psize) << (i * 4)); | |
583 | ||
584 | hpsizes = mm->context.high_slices_psize; | |
585 | for (i = 0; i < SLICE_NUM_HIGH; i++) | |
586 | if (((hpsizes >> (i * 4)) & 0xf) == old_psize) | |
587 | hpsizes = (hpsizes & ~(0xful << (i * 4))) | | |
588 | (((unsigned long)psize) << (i * 4)); | |
589 | ||
590 | mm->context.low_slices_psize = lpsizes; | |
591 | mm->context.high_slices_psize = hpsizes; | |
592 | ||
593 | slice_dbg(" lsps=%lx, hsps=%lx\n", | |
594 | mm->context.low_slices_psize, | |
595 | mm->context.high_slices_psize); | |
596 | ||
597 | bail: | |
598 | spin_unlock_irqrestore(&slice_convert_lock, flags); | |
599 | } | |
600 | ||
601 | /* | |
602 | * is_hugepage_only_range() is used by generic code to verify wether | |
603 | * a normal mmap mapping (non hugetlbfs) is valid on a given area. | |
604 | * | |
605 | * until the generic code provides a more generic hook and/or starts | |
606 | * calling arch get_unmapped_area for MAP_FIXED (which our implementation | |
607 | * here knows how to deal with), we hijack it to keep standard mappings | |
608 | * away from us. | |
609 | * | |
610 | * because of that generic code limitation, MAP_FIXED mapping cannot | |
611 | * "convert" back a slice with no VMAs to the standard page size, only | |
612 | * get_unmapped_area() can. It would be possible to fix it here but I | |
613 | * prefer working on fixing the generic code instead. | |
614 | * | |
615 | * WARNING: This will not work if hugetlbfs isn't enabled since the | |
616 | * generic code will redefine that function as 0 in that. This is ok | |
617 | * for now as we only use slices with hugetlbfs enabled. This should | |
618 | * be fixed as the generic code gets fixed. | |
619 | */ | |
620 | int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr, | |
621 | unsigned long len) | |
622 | { | |
623 | struct slice_mask mask, available; | |
624 | ||
625 | mask = slice_range_to_mask(addr, len); | |
626 | available = slice_mask_for_size(mm, mm->context.user_psize); | |
627 | ||
628 | #if 0 /* too verbose */ | |
629 | slice_dbg("is_hugepage_only_range(mm=%p, addr=%lx, len=%lx)\n", | |
630 | mm, addr, len); | |
631 | slice_print_mask(" mask", mask); | |
632 | slice_print_mask(" available", available); | |
633 | #endif | |
634 | return !slice_check_fit(mask, available); | |
635 | } | |
636 |