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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/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 | ||
39 | /* some sanity checks */ | |
40 | #if (PGTABLE_RANGE >> 43) > SLICE_MASK_SIZE | |
41 | #error PGTABLE_RANGE exceeds slice_mask high_slices size | |
42 | #endif | |
43 | ||
44 | static DEFINE_SPINLOCK(slice_convert_lock); | |
45 | ||
46 | ||
47 | #ifdef DEBUG | |
48 | int _slice_debug = 1; | |
49 | ||
50 | static void slice_print_mask(const char *label, struct slice_mask mask) | |
51 | { | |
52 | char *p, buf[16 + 3 + 64 + 1]; | |
53 | int i; | |
54 | ||
55 | if (!_slice_debug) | |
56 | return; | |
57 | p = buf; | |
58 | for (i = 0; i < SLICE_NUM_LOW; i++) | |
59 | *(p++) = (mask.low_slices & (1 << i)) ? '1' : '0'; | |
60 | *(p++) = ' '; | |
61 | *(p++) = '-'; | |
62 | *(p++) = ' '; | |
63 | for (i = 0; i < SLICE_NUM_HIGH; i++) | |
64 | *(p++) = (mask.high_slices & (1ul << i)) ? '1' : '0'; | |
65 | *(p++) = 0; | |
66 | ||
67 | printk(KERN_DEBUG "%s:%s\n", label, buf); | |
68 | } | |
69 | ||
70 | #define slice_dbg(fmt...) do { if (_slice_debug) pr_debug(fmt); } while(0) | |
71 | ||
72 | #else | |
73 | ||
74 | static void slice_print_mask(const char *label, struct slice_mask mask) {} | |
75 | #define slice_dbg(fmt...) | |
76 | ||
77 | #endif | |
78 | ||
79 | static struct slice_mask slice_range_to_mask(unsigned long start, | |
80 | unsigned long len) | |
81 | { | |
82 | unsigned long end = start + len - 1; | |
83 | struct slice_mask ret = { 0, 0 }; | |
84 | ||
85 | if (start < SLICE_LOW_TOP) { | |
86 | unsigned long mend = min(end, SLICE_LOW_TOP); | |
87 | unsigned long mstart = min(start, SLICE_LOW_TOP); | |
88 | ||
89 | ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1)) | |
90 | - (1u << GET_LOW_SLICE_INDEX(mstart)); | |
91 | } | |
92 | ||
93 | if ((start + len) > SLICE_LOW_TOP) | |
94 | ret.high_slices = (1ul << (GET_HIGH_SLICE_INDEX(end) + 1)) | |
95 | - (1ul << GET_HIGH_SLICE_INDEX(start)); | |
96 | ||
97 | return ret; | |
98 | } | |
99 | ||
100 | static int slice_area_is_free(struct mm_struct *mm, unsigned long addr, | |
101 | unsigned long len) | |
102 | { | |
103 | struct vm_area_struct *vma; | |
104 | ||
105 | if ((mm->task_size - len) < addr) | |
106 | return 0; | |
107 | vma = find_vma(mm, addr); | |
108 | return (!vma || (addr + len) <= vma->vm_start); | |
109 | } | |
110 | ||
111 | static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice) | |
112 | { | |
113 | return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT, | |
114 | 1ul << SLICE_LOW_SHIFT); | |
115 | } | |
116 | ||
117 | static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice) | |
118 | { | |
119 | unsigned long start = slice << SLICE_HIGH_SHIFT; | |
120 | unsigned long end = start + (1ul << SLICE_HIGH_SHIFT); | |
121 | ||
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 | ||
128 | return !slice_area_is_free(mm, start, end - start); | |
129 | } | |
130 | ||
131 | static struct slice_mask slice_mask_for_free(struct mm_struct *mm) | |
132 | { | |
133 | struct slice_mask ret = { 0, 0 }; | |
134 | unsigned long i; | |
135 | ||
136 | for (i = 0; i < SLICE_NUM_LOW; i++) | |
137 | if (!slice_low_has_vma(mm, i)) | |
138 | ret.low_slices |= 1u << i; | |
139 | ||
140 | if (mm->task_size <= SLICE_LOW_TOP) | |
141 | return ret; | |
142 | ||
143 | for (i = 0; i < SLICE_NUM_HIGH; i++) | |
144 | if (!slice_high_has_vma(mm, i)) | |
145 | ret.high_slices |= 1ul << i; | |
146 | ||
147 | return ret; | |
148 | } | |
149 | ||
150 | static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize) | |
151 | { | |
152 | unsigned char *hpsizes; | |
153 | int index, mask_index; | |
154 | struct slice_mask ret = { 0, 0 }; | |
155 | unsigned long i; | |
156 | u64 lpsizes; | |
157 | ||
158 | lpsizes = mm->context.low_slices_psize; | |
159 | for (i = 0; i < SLICE_NUM_LOW; i++) | |
160 | if (((lpsizes >> (i * 4)) & 0xf) == psize) | |
161 | ret.low_slices |= 1u << i; | |
162 | ||
163 | hpsizes = mm->context.high_slices_psize; | |
164 | for (i = 0; i < SLICE_NUM_HIGH; i++) { | |
165 | mask_index = i & 0x1; | |
166 | index = i >> 1; | |
167 | if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == psize) | |
168 | ret.high_slices |= 1ul << i; | |
169 | } | |
170 | ||
171 | return ret; | |
172 | } | |
173 | ||
174 | static int slice_check_fit(struct slice_mask mask, struct slice_mask available) | |
175 | { | |
176 | return (mask.low_slices & available.low_slices) == mask.low_slices && | |
177 | (mask.high_slices & available.high_slices) == mask.high_slices; | |
178 | } | |
179 | ||
180 | static void slice_flush_segments(void *parm) | |
181 | { | |
182 | struct mm_struct *mm = parm; | |
183 | unsigned long flags; | |
184 | ||
185 | if (mm != current->active_mm) | |
186 | return; | |
187 | ||
188 | /* update the paca copy of the context struct */ | |
189 | get_paca()->context = current->active_mm->context; | |
190 | ||
191 | local_irq_save(flags); | |
192 | slb_flush_and_rebolt(); | |
193 | local_irq_restore(flags); | |
194 | } | |
195 | ||
196 | static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psize) | |
197 | { | |
198 | int index, mask_index; | |
199 | /* Write the new slice psize bits */ | |
200 | unsigned char *hpsizes; | |
201 | u64 lpsizes; | |
202 | unsigned long i, flags; | |
203 | ||
204 | slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize); | |
205 | slice_print_mask(" mask", mask); | |
206 | ||
207 | /* We need to use a spinlock here to protect against | |
208 | * concurrent 64k -> 4k demotion ... | |
209 | */ | |
210 | spin_lock_irqsave(&slice_convert_lock, flags); | |
211 | ||
212 | lpsizes = mm->context.low_slices_psize; | |
213 | for (i = 0; i < SLICE_NUM_LOW; i++) | |
214 | if (mask.low_slices & (1u << i)) | |
215 | lpsizes = (lpsizes & ~(0xful << (i * 4))) | | |
216 | (((unsigned long)psize) << (i * 4)); | |
217 | ||
218 | /* Assign the value back */ | |
219 | mm->context.low_slices_psize = lpsizes; | |
220 | ||
221 | hpsizes = mm->context.high_slices_psize; | |
222 | for (i = 0; i < SLICE_NUM_HIGH; i++) { | |
223 | mask_index = i & 0x1; | |
224 | index = i >> 1; | |
225 | if (mask.high_slices & (1ul << i)) | |
226 | hpsizes[index] = (hpsizes[index] & | |
227 | ~(0xf << (mask_index * 4))) | | |
228 | (((unsigned long)psize) << (mask_index * 4)); | |
229 | } | |
230 | ||
231 | slice_dbg(" lsps=%lx, hsps=%lx\n", | |
232 | mm->context.low_slices_psize, | |
233 | mm->context.high_slices_psize); | |
234 | ||
235 | spin_unlock_irqrestore(&slice_convert_lock, flags); | |
236 | ||
237 | copro_flush_all_slbs(mm); | |
238 | } | |
239 | ||
240 | /* | |
241 | * Compute which slice addr is part of; | |
242 | * set *boundary_addr to the start or end boundary of that slice | |
243 | * (depending on 'end' parameter); | |
244 | * return boolean indicating if the slice is marked as available in the | |
245 | * 'available' slice_mark. | |
246 | */ | |
247 | static bool slice_scan_available(unsigned long addr, | |
248 | struct slice_mask available, | |
249 | int end, | |
250 | unsigned long *boundary_addr) | |
251 | { | |
252 | unsigned long slice; | |
253 | if (addr < SLICE_LOW_TOP) { | |
254 | slice = GET_LOW_SLICE_INDEX(addr); | |
255 | *boundary_addr = (slice + end) << SLICE_LOW_SHIFT; | |
256 | return !!(available.low_slices & (1u << slice)); | |
257 | } else { | |
258 | slice = GET_HIGH_SLICE_INDEX(addr); | |
259 | *boundary_addr = (slice + end) ? | |
260 | ((slice + end) << SLICE_HIGH_SHIFT) : SLICE_LOW_TOP; | |
261 | return !!(available.high_slices & (1ul << slice)); | |
262 | } | |
263 | } | |
264 | ||
265 | static unsigned long slice_find_area_bottomup(struct mm_struct *mm, | |
266 | unsigned long len, | |
267 | struct slice_mask available, | |
268 | int psize) | |
269 | { | |
270 | int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); | |
271 | unsigned long addr, found, next_end; | |
272 | struct vm_unmapped_area_info info; | |
273 | ||
274 | info.flags = 0; | |
275 | info.length = len; | |
276 | info.align_mask = PAGE_MASK & ((1ul << pshift) - 1); | |
277 | info.align_offset = 0; | |
278 | ||
279 | addr = TASK_UNMAPPED_BASE; | |
280 | while (addr < TASK_SIZE) { | |
281 | info.low_limit = addr; | |
282 | if (!slice_scan_available(addr, available, 1, &addr)) | |
283 | continue; | |
284 | ||
285 | next_slice: | |
286 | /* | |
287 | * At this point [info.low_limit; addr) covers | |
288 | * available slices only and ends at a slice boundary. | |
289 | * Check if we need to reduce the range, or if we can | |
290 | * extend it to cover the next available slice. | |
291 | */ | |
292 | if (addr >= TASK_SIZE) | |
293 | addr = TASK_SIZE; | |
294 | else if (slice_scan_available(addr, available, 1, &next_end)) { | |
295 | addr = next_end; | |
296 | goto next_slice; | |
297 | } | |
298 | info.high_limit = addr; | |
299 | ||
300 | found = vm_unmapped_area(&info); | |
301 | if (!(found & ~PAGE_MASK)) | |
302 | return found; | |
303 | } | |
304 | ||
305 | return -ENOMEM; | |
306 | } | |
307 | ||
308 | static unsigned long slice_find_area_topdown(struct mm_struct *mm, | |
309 | unsigned long len, | |
310 | struct slice_mask available, | |
311 | int psize) | |
312 | { | |
313 | int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); | |
314 | unsigned long addr, found, prev; | |
315 | struct vm_unmapped_area_info info; | |
316 | ||
317 | info.flags = VM_UNMAPPED_AREA_TOPDOWN; | |
318 | info.length = len; | |
319 | info.align_mask = PAGE_MASK & ((1ul << pshift) - 1); | |
320 | info.align_offset = 0; | |
321 | ||
322 | addr = mm->mmap_base; | |
323 | while (addr > PAGE_SIZE) { | |
324 | info.high_limit = addr; | |
325 | if (!slice_scan_available(addr - 1, available, 0, &addr)) | |
326 | continue; | |
327 | ||
328 | prev_slice: | |
329 | /* | |
330 | * At this point [addr; info.high_limit) covers | |
331 | * available slices only and starts at a slice boundary. | |
332 | * Check if we need to reduce the range, or if we can | |
333 | * extend it to cover the previous available slice. | |
334 | */ | |
335 | if (addr < PAGE_SIZE) | |
336 | addr = PAGE_SIZE; | |
337 | else if (slice_scan_available(addr - 1, available, 0, &prev)) { | |
338 | addr = prev; | |
339 | goto prev_slice; | |
340 | } | |
341 | info.low_limit = addr; | |
342 | ||
343 | found = vm_unmapped_area(&info); | |
344 | if (!(found & ~PAGE_MASK)) | |
345 | return found; | |
346 | } | |
347 | ||
348 | /* | |
349 | * A failed mmap() very likely causes application failure, | |
350 | * so fall back to the bottom-up function here. This scenario | |
351 | * can happen with large stack limits and large mmap() | |
352 | * allocations. | |
353 | */ | |
354 | return slice_find_area_bottomup(mm, len, available, psize); | |
355 | } | |
356 | ||
357 | ||
358 | static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len, | |
359 | struct slice_mask mask, int psize, | |
360 | int topdown) | |
361 | { | |
362 | if (topdown) | |
363 | return slice_find_area_topdown(mm, len, mask, psize); | |
364 | else | |
365 | return slice_find_area_bottomup(mm, len, mask, psize); | |
366 | } | |
367 | ||
368 | #define or_mask(dst, src) do { \ | |
369 | (dst).low_slices |= (src).low_slices; \ | |
370 | (dst).high_slices |= (src).high_slices; \ | |
371 | } while (0) | |
372 | ||
373 | #define andnot_mask(dst, src) do { \ | |
374 | (dst).low_slices &= ~(src).low_slices; \ | |
375 | (dst).high_slices &= ~(src).high_slices; \ | |
376 | } while (0) | |
377 | ||
378 | #ifdef CONFIG_PPC_64K_PAGES | |
379 | #define MMU_PAGE_BASE MMU_PAGE_64K | |
380 | #else | |
381 | #define MMU_PAGE_BASE MMU_PAGE_4K | |
382 | #endif | |
383 | ||
384 | unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len, | |
385 | unsigned long flags, unsigned int psize, | |
386 | int topdown) | |
387 | { | |
388 | struct slice_mask mask = {0, 0}; | |
389 | struct slice_mask good_mask; | |
390 | struct slice_mask potential_mask = {0,0} /* silence stupid warning */; | |
391 | struct slice_mask compat_mask = {0, 0}; | |
392 | int fixed = (flags & MAP_FIXED); | |
393 | int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT); | |
394 | struct mm_struct *mm = current->mm; | |
395 | unsigned long newaddr; | |
396 | ||
397 | /* Sanity checks */ | |
398 | BUG_ON(mm->task_size == 0); | |
399 | ||
400 | slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize); | |
401 | slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n", | |
402 | addr, len, flags, topdown); | |
403 | ||
404 | if (len > mm->task_size) | |
405 | return -ENOMEM; | |
406 | if (len & ((1ul << pshift) - 1)) | |
407 | return -EINVAL; | |
408 | if (fixed && (addr & ((1ul << pshift) - 1))) | |
409 | return -EINVAL; | |
410 | if (fixed && addr > (mm->task_size - len)) | |
411 | return -ENOMEM; | |
412 | ||
413 | /* If hint, make sure it matches our alignment restrictions */ | |
414 | if (!fixed && addr) { | |
415 | addr = _ALIGN_UP(addr, 1ul << pshift); | |
416 | slice_dbg(" aligned addr=%lx\n", addr); | |
417 | /* Ignore hint if it's too large or overlaps a VMA */ | |
418 | if (addr > mm->task_size - len || | |
419 | !slice_area_is_free(mm, addr, len)) | |
420 | addr = 0; | |
421 | } | |
422 | ||
423 | /* First make up a "good" mask of slices that have the right size | |
424 | * already | |
425 | */ | |
426 | good_mask = slice_mask_for_size(mm, psize); | |
427 | slice_print_mask(" good_mask", good_mask); | |
428 | ||
429 | /* | |
430 | * Here "good" means slices that are already the right page size, | |
431 | * "compat" means slices that have a compatible page size (i.e. | |
432 | * 4k in a 64k pagesize kernel), and "free" means slices without | |
433 | * any VMAs. | |
434 | * | |
435 | * If MAP_FIXED: | |
436 | * check if fits in good | compat => OK | |
437 | * check if fits in good | compat | free => convert free | |
438 | * else bad | |
439 | * If have hint: | |
440 | * check if hint fits in good => OK | |
441 | * check if hint fits in good | free => convert free | |
442 | * Otherwise: | |
443 | * search in good, found => OK | |
444 | * search in good | free, found => convert free | |
445 | * search in good | compat | free, found => convert free. | |
446 | */ | |
447 | ||
448 | #ifdef CONFIG_PPC_64K_PAGES | |
449 | /* If we support combo pages, we can allow 64k pages in 4k slices */ | |
450 | if (psize == MMU_PAGE_64K) { | |
451 | compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K); | |
452 | if (fixed) | |
453 | or_mask(good_mask, compat_mask); | |
454 | } | |
455 | #endif | |
456 | ||
457 | /* First check hint if it's valid or if we have MAP_FIXED */ | |
458 | if (addr != 0 || fixed) { | |
459 | /* Build a mask for the requested range */ | |
460 | mask = slice_range_to_mask(addr, len); | |
461 | slice_print_mask(" mask", mask); | |
462 | ||
463 | /* Check if we fit in the good mask. If we do, we just return, | |
464 | * nothing else to do | |
465 | */ | |
466 | if (slice_check_fit(mask, good_mask)) { | |
467 | slice_dbg(" fits good !\n"); | |
468 | return addr; | |
469 | } | |
470 | } else { | |
471 | /* Now let's see if we can find something in the existing | |
472 | * slices for that size | |
473 | */ | |
474 | newaddr = slice_find_area(mm, len, good_mask, psize, topdown); | |
475 | if (newaddr != -ENOMEM) { | |
476 | /* Found within the good mask, we don't have to setup, | |
477 | * we thus return directly | |
478 | */ | |
479 | slice_dbg(" found area at 0x%lx\n", newaddr); | |
480 | return newaddr; | |
481 | } | |
482 | } | |
483 | ||
484 | /* We don't fit in the good mask, check what other slices are | |
485 | * empty and thus can be converted | |
486 | */ | |
487 | potential_mask = slice_mask_for_free(mm); | |
488 | or_mask(potential_mask, good_mask); | |
489 | slice_print_mask(" potential", potential_mask); | |
490 | ||
491 | if ((addr != 0 || fixed) && slice_check_fit(mask, potential_mask)) { | |
492 | slice_dbg(" fits potential !\n"); | |
493 | goto convert; | |
494 | } | |
495 | ||
496 | /* If we have MAP_FIXED and failed the above steps, then error out */ | |
497 | if (fixed) | |
498 | return -EBUSY; | |
499 | ||
500 | slice_dbg(" search...\n"); | |
501 | ||
502 | /* If we had a hint that didn't work out, see if we can fit | |
503 | * anywhere in the good area. | |
504 | */ | |
505 | if (addr) { | |
506 | addr = slice_find_area(mm, len, good_mask, psize, topdown); | |
507 | if (addr != -ENOMEM) { | |
508 | slice_dbg(" found area at 0x%lx\n", addr); | |
509 | return addr; | |
510 | } | |
511 | } | |
512 | ||
513 | /* Now let's see if we can find something in the existing slices | |
514 | * for that size plus free slices | |
515 | */ | |
516 | addr = slice_find_area(mm, len, potential_mask, psize, topdown); | |
517 | ||
518 | #ifdef CONFIG_PPC_64K_PAGES | |
519 | if (addr == -ENOMEM && psize == MMU_PAGE_64K) { | |
520 | /* retry the search with 4k-page slices included */ | |
521 | or_mask(potential_mask, compat_mask); | |
522 | addr = slice_find_area(mm, len, potential_mask, psize, | |
523 | topdown); | |
524 | } | |
525 | #endif | |
526 | ||
527 | if (addr == -ENOMEM) | |
528 | return -ENOMEM; | |
529 | ||
530 | mask = slice_range_to_mask(addr, len); | |
531 | slice_dbg(" found potential area at 0x%lx\n", addr); | |
532 | slice_print_mask(" mask", mask); | |
533 | ||
534 | convert: | |
535 | andnot_mask(mask, good_mask); | |
536 | andnot_mask(mask, compat_mask); | |
537 | if (mask.low_slices || mask.high_slices) { | |
538 | slice_convert(mm, mask, psize); | |
539 | if (psize > MMU_PAGE_BASE) | |
540 | on_each_cpu(slice_flush_segments, mm, 1); | |
541 | } | |
542 | return addr; | |
543 | ||
544 | } | |
545 | EXPORT_SYMBOL_GPL(slice_get_unmapped_area); | |
546 | ||
547 | unsigned long arch_get_unmapped_area(struct file *filp, | |
548 | unsigned long addr, | |
549 | unsigned long len, | |
550 | unsigned long pgoff, | |
551 | unsigned long flags) | |
552 | { | |
553 | return slice_get_unmapped_area(addr, len, flags, | |
554 | current->mm->context.user_psize, 0); | |
555 | } | |
556 | ||
557 | unsigned long arch_get_unmapped_area_topdown(struct file *filp, | |
558 | const unsigned long addr0, | |
559 | const unsigned long len, | |
560 | const unsigned long pgoff, | |
561 | const unsigned long flags) | |
562 | { | |
563 | return slice_get_unmapped_area(addr0, len, flags, | |
564 | current->mm->context.user_psize, 1); | |
565 | } | |
566 | ||
567 | unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr) | |
568 | { | |
569 | unsigned char *hpsizes; | |
570 | int index, mask_index; | |
571 | ||
572 | if (addr < SLICE_LOW_TOP) { | |
573 | u64 lpsizes; | |
574 | lpsizes = mm->context.low_slices_psize; | |
575 | index = GET_LOW_SLICE_INDEX(addr); | |
576 | return (lpsizes >> (index * 4)) & 0xf; | |
577 | } | |
578 | hpsizes = mm->context.high_slices_psize; | |
579 | index = GET_HIGH_SLICE_INDEX(addr); | |
580 | mask_index = index & 0x1; | |
581 | return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xf; | |
582 | } | |
583 | EXPORT_SYMBOL_GPL(get_slice_psize); | |
584 | ||
585 | /* | |
586 | * This is called by hash_page when it needs to do a lazy conversion of | |
587 | * an address space from real 64K pages to combo 4K pages (typically | |
588 | * when hitting a non cacheable mapping on a processor or hypervisor | |
589 | * that won't allow them for 64K pages). | |
590 | * | |
591 | * This is also called in init_new_context() to change back the user | |
592 | * psize from whatever the parent context had it set to | |
593 | * N.B. This may be called before mm->context.id has been set. | |
594 | * | |
595 | * This function will only change the content of the {low,high)_slice_psize | |
596 | * masks, it will not flush SLBs as this shall be handled lazily by the | |
597 | * caller. | |
598 | */ | |
599 | void slice_set_user_psize(struct mm_struct *mm, unsigned int psize) | |
600 | { | |
601 | int index, mask_index; | |
602 | unsigned char *hpsizes; | |
603 | unsigned long flags, lpsizes; | |
604 | unsigned int old_psize; | |
605 | int i; | |
606 | ||
607 | slice_dbg("slice_set_user_psize(mm=%p, psize=%d)\n", mm, psize); | |
608 | ||
609 | spin_lock_irqsave(&slice_convert_lock, flags); | |
610 | ||
611 | old_psize = mm->context.user_psize; | |
612 | slice_dbg(" old_psize=%d\n", old_psize); | |
613 | if (old_psize == psize) | |
614 | goto bail; | |
615 | ||
616 | mm->context.user_psize = psize; | |
617 | wmb(); | |
618 | ||
619 | lpsizes = mm->context.low_slices_psize; | |
620 | for (i = 0; i < SLICE_NUM_LOW; i++) | |
621 | if (((lpsizes >> (i * 4)) & 0xf) == old_psize) | |
622 | lpsizes = (lpsizes & ~(0xful << (i * 4))) | | |
623 | (((unsigned long)psize) << (i * 4)); | |
624 | /* Assign the value back */ | |
625 | mm->context.low_slices_psize = lpsizes; | |
626 | ||
627 | hpsizes = mm->context.high_slices_psize; | |
628 | for (i = 0; i < SLICE_NUM_HIGH; i++) { | |
629 | mask_index = i & 0x1; | |
630 | index = i >> 1; | |
631 | if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == old_psize) | |
632 | hpsizes[index] = (hpsizes[index] & | |
633 | ~(0xf << (mask_index * 4))) | | |
634 | (((unsigned long)psize) << (mask_index * 4)); | |
635 | } | |
636 | ||
637 | ||
638 | ||
639 | ||
640 | slice_dbg(" lsps=%lx, hsps=%lx\n", | |
641 | mm->context.low_slices_psize, | |
642 | mm->context.high_slices_psize); | |
643 | ||
644 | bail: | |
645 | spin_unlock_irqrestore(&slice_convert_lock, flags); | |
646 | } | |
647 | ||
648 | void slice_set_range_psize(struct mm_struct *mm, unsigned long start, | |
649 | unsigned long len, unsigned int psize) | |
650 | { | |
651 | struct slice_mask mask = slice_range_to_mask(start, len); | |
652 | ||
653 | slice_convert(mm, mask, psize); | |
654 | } | |
655 | ||
656 | #ifdef CONFIG_HUGETLB_PAGE | |
657 | /* | |
658 | * is_hugepage_only_range() is used by generic code to verify whether | |
659 | * a normal mmap mapping (non hugetlbfs) is valid on a given area. | |
660 | * | |
661 | * until the generic code provides a more generic hook and/or starts | |
662 | * calling arch get_unmapped_area for MAP_FIXED (which our implementation | |
663 | * here knows how to deal with), we hijack it to keep standard mappings | |
664 | * away from us. | |
665 | * | |
666 | * because of that generic code limitation, MAP_FIXED mapping cannot | |
667 | * "convert" back a slice with no VMAs to the standard page size, only | |
668 | * get_unmapped_area() can. It would be possible to fix it here but I | |
669 | * prefer working on fixing the generic code instead. | |
670 | * | |
671 | * WARNING: This will not work if hugetlbfs isn't enabled since the | |
672 | * generic code will redefine that function as 0 in that. This is ok | |
673 | * for now as we only use slices with hugetlbfs enabled. This should | |
674 | * be fixed as the generic code gets fixed. | |
675 | */ | |
676 | int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr, | |
677 | unsigned long len) | |
678 | { | |
679 | struct slice_mask mask, available; | |
680 | unsigned int psize = mm->context.user_psize; | |
681 | ||
682 | mask = slice_range_to_mask(addr, len); | |
683 | available = slice_mask_for_size(mm, psize); | |
684 | #ifdef CONFIG_PPC_64K_PAGES | |
685 | /* We need to account for 4k slices too */ | |
686 | if (psize == MMU_PAGE_64K) { | |
687 | struct slice_mask compat_mask; | |
688 | compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K); | |
689 | or_mask(available, compat_mask); | |
690 | } | |
691 | #endif | |
692 | ||
693 | #if 0 /* too verbose */ | |
694 | slice_dbg("is_hugepage_only_range(mm=%p, addr=%lx, len=%lx)\n", | |
695 | mm, addr, len); | |
696 | slice_print_mask(" mask", mask); | |
697 | slice_print_mask(" available", available); | |
698 | #endif | |
699 | return !slice_check_fit(mask, available); | |
700 | } | |
701 | #endif |