]>
Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1e133ab2 MS |
2 | /* |
3 | * Page table allocation functions | |
4 | * | |
5 | * Copyright IBM Corp. 2016 | |
6 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> | |
7 | */ | |
8 | ||
1e133ab2 | 9 | #include <linux/sysctl.h> |
1caf170d HC |
10 | #include <linux/slab.h> |
11 | #include <linux/mm.h> | |
1e133ab2 MS |
12 | #include <asm/mmu_context.h> |
13 | #include <asm/pgalloc.h> | |
14 | #include <asm/gmap.h> | |
15 | #include <asm/tlb.h> | |
16 | #include <asm/tlbflush.h> | |
17 | ||
18 | #ifdef CONFIG_PGSTE | |
19 | ||
20 | static int page_table_allocate_pgste_min = 0; | |
21 | static int page_table_allocate_pgste_max = 1; | |
22 | int page_table_allocate_pgste = 0; | |
23 | EXPORT_SYMBOL(page_table_allocate_pgste); | |
24 | ||
25 | static struct ctl_table page_table_sysctl[] = { | |
26 | { | |
27 | .procname = "allocate_pgste", | |
28 | .data = &page_table_allocate_pgste, | |
29 | .maxlen = sizeof(int), | |
30 | .mode = S_IRUGO | S_IWUSR, | |
5bedf8aa | 31 | .proc_handler = proc_dointvec_minmax, |
1e133ab2 MS |
32 | .extra1 = &page_table_allocate_pgste_min, |
33 | .extra2 = &page_table_allocate_pgste_max, | |
34 | }, | |
35 | { } | |
36 | }; | |
37 | ||
38 | static struct ctl_table page_table_sysctl_dir[] = { | |
39 | { | |
40 | .procname = "vm", | |
41 | .maxlen = 0, | |
42 | .mode = 0555, | |
43 | .child = page_table_sysctl, | |
44 | }, | |
45 | { } | |
46 | }; | |
47 | ||
48 | static int __init page_table_register_sysctl(void) | |
49 | { | |
50 | return register_sysctl_table(page_table_sysctl_dir) ? 0 : -ENOMEM; | |
51 | } | |
52 | __initcall(page_table_register_sysctl); | |
53 | ||
54 | #endif /* CONFIG_PGSTE */ | |
55 | ||
56 | unsigned long *crst_table_alloc(struct mm_struct *mm) | |
57 | { | |
58 | struct page *page = alloc_pages(GFP_KERNEL, 2); | |
59 | ||
60 | if (!page) | |
61 | return NULL; | |
c9b5ad54 | 62 | arch_set_page_dat(page, 2); |
1e133ab2 MS |
63 | return (unsigned long *) page_to_phys(page); |
64 | } | |
65 | ||
66 | void crst_table_free(struct mm_struct *mm, unsigned long *table) | |
67 | { | |
68 | free_pages((unsigned long) table, 2); | |
69 | } | |
70 | ||
71 | static void __crst_table_upgrade(void *arg) | |
72 | { | |
73 | struct mm_struct *mm = arg; | |
74 | ||
0aaba41b | 75 | if (current->active_mm == mm) |
1e133ab2 | 76 | set_user_asce(mm); |
1e133ab2 MS |
77 | __tlb_flush_local(); |
78 | } | |
79 | ||
1aea9b3f | 80 | int crst_table_upgrade(struct mm_struct *mm, unsigned long end) |
1e133ab2 MS |
81 | { |
82 | unsigned long *table, *pgd; | |
1aea9b3f | 83 | int rc, notify; |
1e133ab2 | 84 | |
1aea9b3f | 85 | /* upgrade should only happen from 3 to 4, 3 to 5, or 4 to 5 levels */ |
2fc4876e | 86 | VM_BUG_ON(mm->context.asce_limit < _REGION2_SIZE); |
1aea9b3f MS |
87 | rc = 0; |
88 | notify = 0; | |
89 | while (mm->context.asce_limit < end) { | |
90 | table = crst_table_alloc(mm); | |
91 | if (!table) { | |
92 | rc = -ENOMEM; | |
93 | break; | |
94 | } | |
95 | spin_lock_bh(&mm->page_table_lock); | |
96 | pgd = (unsigned long *) mm->pgd; | |
f1c1174f | 97 | if (mm->context.asce_limit == _REGION2_SIZE) { |
1aea9b3f MS |
98 | crst_table_init(table, _REGION2_ENTRY_EMPTY); |
99 | p4d_populate(mm, (p4d_t *) table, (pud_t *) pgd); | |
100 | mm->pgd = (pgd_t *) table; | |
f1c1174f | 101 | mm->context.asce_limit = _REGION1_SIZE; |
1aea9b3f MS |
102 | mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | |
103 | _ASCE_USER_BITS | _ASCE_TYPE_REGION2; | |
104 | } else { | |
105 | crst_table_init(table, _REGION1_ENTRY_EMPTY); | |
106 | pgd_populate(mm, (pgd_t *) table, (p4d_t *) pgd); | |
107 | mm->pgd = (pgd_t *) table; | |
108 | mm->context.asce_limit = -PAGE_SIZE; | |
109 | mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | | |
110 | _ASCE_USER_BITS | _ASCE_TYPE_REGION1; | |
111 | } | |
112 | notify = 1; | |
113 | spin_unlock_bh(&mm->page_table_lock); | |
114 | } | |
115 | if (notify) | |
116 | on_each_cpu(__crst_table_upgrade, mm, 0); | |
117 | return rc; | |
1e133ab2 MS |
118 | } |
119 | ||
723cacbd | 120 | void crst_table_downgrade(struct mm_struct *mm) |
1e133ab2 MS |
121 | { |
122 | pgd_t *pgd; | |
123 | ||
723cacbd | 124 | /* downgrade should only happen from 3 to 2 levels (compat only) */ |
2fc4876e | 125 | VM_BUG_ON(mm->context.asce_limit != _REGION2_SIZE); |
723cacbd | 126 | |
1e133ab2 MS |
127 | if (current->active_mm == mm) { |
128 | clear_user_asce(); | |
129 | __tlb_flush_mm(mm); | |
130 | } | |
723cacbd GS |
131 | |
132 | pgd = mm->pgd; | |
133 | mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN); | |
f1c1174f | 134 | mm->context.asce_limit = _REGION3_SIZE; |
723cacbd GS |
135 | mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | |
136 | _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT; | |
723cacbd GS |
137 | crst_table_free(mm, (unsigned long *) pgd); |
138 | ||
1e133ab2 MS |
139 | if (current->active_mm == mm) |
140 | set_user_asce(mm); | |
141 | } | |
142 | ||
143 | static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits) | |
144 | { | |
145 | unsigned int old, new; | |
146 | ||
147 | do { | |
148 | old = atomic_read(v); | |
149 | new = old ^ bits; | |
150 | } while (atomic_cmpxchg(v, old, new) != old); | |
151 | return new; | |
152 | } | |
153 | ||
4be130a0 MS |
154 | #ifdef CONFIG_PGSTE |
155 | ||
156 | struct page *page_table_alloc_pgste(struct mm_struct *mm) | |
157 | { | |
158 | struct page *page; | |
41879ff6 | 159 | u64 *table; |
4be130a0 | 160 | |
faee35a5 | 161 | page = alloc_page(GFP_KERNEL); |
4be130a0 | 162 | if (page) { |
41879ff6 HC |
163 | table = (u64 *)page_to_phys(page); |
164 | memset64(table, _PAGE_INVALID, PTRS_PER_PTE); | |
165 | memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE); | |
4be130a0 MS |
166 | } |
167 | return page; | |
168 | } | |
169 | ||
170 | void page_table_free_pgste(struct page *page) | |
171 | { | |
172 | __free_page(page); | |
173 | } | |
174 | ||
175 | #endif /* CONFIG_PGSTE */ | |
176 | ||
1e133ab2 MS |
177 | /* |
178 | * page table entry allocation/free routines. | |
179 | */ | |
180 | unsigned long *page_table_alloc(struct mm_struct *mm) | |
181 | { | |
182 | unsigned long *table; | |
183 | struct page *page; | |
184 | unsigned int mask, bit; | |
185 | ||
186 | /* Try to get a fragment of a 4K page as a 2K page table */ | |
187 | if (!mm_alloc_pgste(mm)) { | |
188 | table = NULL; | |
f28a4b4d | 189 | spin_lock_bh(&mm->context.lock); |
1e133ab2 MS |
190 | if (!list_empty(&mm->context.pgtable_list)) { |
191 | page = list_first_entry(&mm->context.pgtable_list, | |
192 | struct page, lru); | |
620b4e90 | 193 | mask = atomic_read(&page->_refcount) >> 24; |
1e133ab2 MS |
194 | mask = (mask | (mask >> 4)) & 3; |
195 | if (mask != 3) { | |
196 | table = (unsigned long *) page_to_phys(page); | |
197 | bit = mask & 1; /* =1 -> second 2K */ | |
198 | if (bit) | |
199 | table += PTRS_PER_PTE; | |
620b4e90 MW |
200 | atomic_xor_bits(&page->_refcount, |
201 | 1U << (bit + 24)); | |
1e133ab2 MS |
202 | list_del(&page->lru); |
203 | } | |
204 | } | |
f28a4b4d | 205 | spin_unlock_bh(&mm->context.lock); |
1e133ab2 MS |
206 | if (table) |
207 | return table; | |
208 | } | |
209 | /* Allocate a fresh page */ | |
10d58bf2 | 210 | page = alloc_page(GFP_KERNEL); |
1e133ab2 MS |
211 | if (!page) |
212 | return NULL; | |
213 | if (!pgtable_page_ctor(page)) { | |
214 | __free_page(page); | |
215 | return NULL; | |
216 | } | |
c9b5ad54 | 217 | arch_set_page_dat(page, 0); |
1e133ab2 MS |
218 | /* Initialize page table */ |
219 | table = (unsigned long *) page_to_phys(page); | |
220 | if (mm_alloc_pgste(mm)) { | |
221 | /* Return 4K page table with PGSTEs */ | |
620b4e90 | 222 | atomic_xor_bits(&page->_refcount, 3 << 24); |
41879ff6 HC |
223 | memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE); |
224 | memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE); | |
1e133ab2 MS |
225 | } else { |
226 | /* Return the first 2K fragment of the page */ | |
620b4e90 | 227 | atomic_xor_bits(&page->_refcount, 1 << 24); |
41879ff6 | 228 | memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE); |
f28a4b4d | 229 | spin_lock_bh(&mm->context.lock); |
1e133ab2 | 230 | list_add(&page->lru, &mm->context.pgtable_list); |
f28a4b4d | 231 | spin_unlock_bh(&mm->context.lock); |
1e133ab2 MS |
232 | } |
233 | return table; | |
234 | } | |
235 | ||
236 | void page_table_free(struct mm_struct *mm, unsigned long *table) | |
237 | { | |
238 | struct page *page; | |
239 | unsigned int bit, mask; | |
240 | ||
241 | page = pfn_to_page(__pa(table) >> PAGE_SHIFT); | |
242 | if (!mm_alloc_pgste(mm)) { | |
243 | /* Free 2K page table fragment of a 4K page */ | |
244 | bit = (__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t)); | |
f28a4b4d | 245 | spin_lock_bh(&mm->context.lock); |
620b4e90 MW |
246 | mask = atomic_xor_bits(&page->_refcount, 1U << (bit + 24)); |
247 | mask >>= 24; | |
1e133ab2 MS |
248 | if (mask & 3) |
249 | list_add(&page->lru, &mm->context.pgtable_list); | |
250 | else | |
251 | list_del(&page->lru); | |
f28a4b4d | 252 | spin_unlock_bh(&mm->context.lock); |
1e133ab2 MS |
253 | if (mask != 0) |
254 | return; | |
255 | } | |
256 | ||
257 | pgtable_page_dtor(page); | |
1e133ab2 MS |
258 | __free_page(page); |
259 | } | |
260 | ||
261 | void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table, | |
262 | unsigned long vmaddr) | |
263 | { | |
264 | struct mm_struct *mm; | |
265 | struct page *page; | |
266 | unsigned int bit, mask; | |
267 | ||
268 | mm = tlb->mm; | |
269 | page = pfn_to_page(__pa(table) >> PAGE_SHIFT); | |
270 | if (mm_alloc_pgste(mm)) { | |
271 | gmap_unlink(mm, table, vmaddr); | |
272 | table = (unsigned long *) (__pa(table) | 3); | |
273 | tlb_remove_table(tlb, table); | |
274 | return; | |
275 | } | |
276 | bit = (__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t)); | |
f28a4b4d | 277 | spin_lock_bh(&mm->context.lock); |
620b4e90 MW |
278 | mask = atomic_xor_bits(&page->_refcount, 0x11U << (bit + 24)); |
279 | mask >>= 24; | |
1e133ab2 MS |
280 | if (mask & 3) |
281 | list_add_tail(&page->lru, &mm->context.pgtable_list); | |
282 | else | |
283 | list_del(&page->lru); | |
f28a4b4d | 284 | spin_unlock_bh(&mm->context.lock); |
1e133ab2 MS |
285 | table = (unsigned long *) (__pa(table) | (1U << bit)); |
286 | tlb_remove_table(tlb, table); | |
287 | } | |
288 | ||
289 | static void __tlb_remove_table(void *_table) | |
290 | { | |
291 | unsigned int mask = (unsigned long) _table & 3; | |
292 | void *table = (void *)((unsigned long) _table ^ mask); | |
293 | struct page *page = pfn_to_page(__pa(table) >> PAGE_SHIFT); | |
294 | ||
295 | switch (mask) { | |
1aea9b3f | 296 | case 0: /* pmd, pud, or p4d */ |
1e133ab2 MS |
297 | free_pages((unsigned long) table, 2); |
298 | break; | |
299 | case 1: /* lower 2K of a 4K page table */ | |
300 | case 2: /* higher 2K of a 4K page table */ | |
620b4e90 MW |
301 | mask = atomic_xor_bits(&page->_refcount, mask << (4 + 24)); |
302 | mask >>= 24; | |
303 | if (mask != 0) | |
1e133ab2 MS |
304 | break; |
305 | /* fallthrough */ | |
306 | case 3: /* 4K page table with pgstes */ | |
307 | pgtable_page_dtor(page); | |
1e133ab2 MS |
308 | __free_page(page); |
309 | break; | |
310 | } | |
311 | } | |
312 | ||
313 | static void tlb_remove_table_smp_sync(void *arg) | |
314 | { | |
315 | /* Simply deliver the interrupt */ | |
316 | } | |
317 | ||
318 | static void tlb_remove_table_one(void *table) | |
319 | { | |
320 | /* | |
321 | * This isn't an RCU grace period and hence the page-tables cannot be | |
322 | * assumed to be actually RCU-freed. | |
323 | * | |
324 | * It is however sufficient for software page-table walkers that rely | |
325 | * on IRQ disabling. See the comment near struct mmu_table_batch. | |
326 | */ | |
327 | smp_call_function(tlb_remove_table_smp_sync, NULL, 1); | |
328 | __tlb_remove_table(table); | |
329 | } | |
330 | ||
331 | static void tlb_remove_table_rcu(struct rcu_head *head) | |
332 | { | |
333 | struct mmu_table_batch *batch; | |
334 | int i; | |
335 | ||
336 | batch = container_of(head, struct mmu_table_batch, rcu); | |
337 | ||
338 | for (i = 0; i < batch->nr; i++) | |
339 | __tlb_remove_table(batch->tables[i]); | |
340 | ||
341 | free_page((unsigned long)batch); | |
342 | } | |
343 | ||
344 | void tlb_table_flush(struct mmu_gather *tlb) | |
345 | { | |
346 | struct mmu_table_batch **batch = &tlb->batch; | |
347 | ||
348 | if (*batch) { | |
349 | call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu); | |
350 | *batch = NULL; | |
351 | } | |
352 | } | |
353 | ||
354 | void tlb_remove_table(struct mmu_gather *tlb, void *table) | |
355 | { | |
356 | struct mmu_table_batch **batch = &tlb->batch; | |
357 | ||
358 | tlb->mm->context.flush_mm = 1; | |
359 | if (*batch == NULL) { | |
360 | *batch = (struct mmu_table_batch *) | |
361 | __get_free_page(GFP_NOWAIT | __GFP_NOWARN); | |
362 | if (*batch == NULL) { | |
363 | __tlb_flush_mm_lazy(tlb->mm); | |
364 | tlb_remove_table_one(table); | |
365 | return; | |
366 | } | |
367 | (*batch)->nr = 0; | |
368 | } | |
369 | (*batch)->tables[(*batch)->nr++] = table; | |
370 | if ((*batch)->nr == MAX_TABLE_BATCH) | |
371 | tlb_flush_mmu(tlb); | |
372 | } | |
1caf170d HC |
373 | |
374 | /* | |
375 | * Base infrastructure required to generate basic asces, region, segment, | |
376 | * and page tables that do not make use of enhanced features like EDAT1. | |
377 | */ | |
378 | ||
379 | static struct kmem_cache *base_pgt_cache; | |
380 | ||
381 | static unsigned long base_pgt_alloc(void) | |
382 | { | |
383 | u64 *table; | |
384 | ||
385 | table = kmem_cache_alloc(base_pgt_cache, GFP_KERNEL); | |
386 | if (table) | |
387 | memset64(table, _PAGE_INVALID, PTRS_PER_PTE); | |
388 | return (unsigned long) table; | |
389 | } | |
390 | ||
391 | static void base_pgt_free(unsigned long table) | |
392 | { | |
393 | kmem_cache_free(base_pgt_cache, (void *) table); | |
394 | } | |
395 | ||
396 | static unsigned long base_crst_alloc(unsigned long val) | |
397 | { | |
398 | unsigned long table; | |
399 | ||
400 | table = __get_free_pages(GFP_KERNEL, CRST_ALLOC_ORDER); | |
401 | if (table) | |
402 | crst_table_init((unsigned long *)table, val); | |
403 | return table; | |
404 | } | |
405 | ||
406 | static void base_crst_free(unsigned long table) | |
407 | { | |
408 | free_pages(table, CRST_ALLOC_ORDER); | |
409 | } | |
410 | ||
411 | #define BASE_ADDR_END_FUNC(NAME, SIZE) \ | |
412 | static inline unsigned long base_##NAME##_addr_end(unsigned long addr, \ | |
413 | unsigned long end) \ | |
414 | { \ | |
415 | unsigned long next = (addr + (SIZE)) & ~((SIZE) - 1); \ | |
416 | \ | |
417 | return (next - 1) < (end - 1) ? next : end; \ | |
418 | } | |
419 | ||
420 | BASE_ADDR_END_FUNC(page, _PAGE_SIZE) | |
421 | BASE_ADDR_END_FUNC(segment, _SEGMENT_SIZE) | |
422 | BASE_ADDR_END_FUNC(region3, _REGION3_SIZE) | |
423 | BASE_ADDR_END_FUNC(region2, _REGION2_SIZE) | |
424 | BASE_ADDR_END_FUNC(region1, _REGION1_SIZE) | |
425 | ||
426 | static inline unsigned long base_lra(unsigned long address) | |
427 | { | |
428 | unsigned long real; | |
429 | ||
430 | asm volatile( | |
431 | " lra %0,0(%1)\n" | |
432 | : "=d" (real) : "a" (address) : "cc"); | |
433 | return real; | |
434 | } | |
435 | ||
436 | static int base_page_walk(unsigned long origin, unsigned long addr, | |
437 | unsigned long end, int alloc) | |
438 | { | |
439 | unsigned long *pte, next; | |
440 | ||
441 | if (!alloc) | |
442 | return 0; | |
443 | pte = (unsigned long *) origin; | |
444 | pte += (addr & _PAGE_INDEX) >> _PAGE_SHIFT; | |
445 | do { | |
446 | next = base_page_addr_end(addr, end); | |
447 | *pte = base_lra(addr); | |
448 | } while (pte++, addr = next, addr < end); | |
449 | return 0; | |
450 | } | |
451 | ||
452 | static int base_segment_walk(unsigned long origin, unsigned long addr, | |
453 | unsigned long end, int alloc) | |
454 | { | |
455 | unsigned long *ste, next, table; | |
456 | int rc; | |
457 | ||
458 | ste = (unsigned long *) origin; | |
459 | ste += (addr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT; | |
460 | do { | |
461 | next = base_segment_addr_end(addr, end); | |
462 | if (*ste & _SEGMENT_ENTRY_INVALID) { | |
463 | if (!alloc) | |
464 | continue; | |
465 | table = base_pgt_alloc(); | |
466 | if (!table) | |
467 | return -ENOMEM; | |
468 | *ste = table | _SEGMENT_ENTRY; | |
469 | } | |
470 | table = *ste & _SEGMENT_ENTRY_ORIGIN; | |
471 | rc = base_page_walk(table, addr, next, alloc); | |
472 | if (rc) | |
473 | return rc; | |
474 | if (!alloc) | |
475 | base_pgt_free(table); | |
476 | cond_resched(); | |
477 | } while (ste++, addr = next, addr < end); | |
478 | return 0; | |
479 | } | |
480 | ||
481 | static int base_region3_walk(unsigned long origin, unsigned long addr, | |
482 | unsigned long end, int alloc) | |
483 | { | |
484 | unsigned long *rtte, next, table; | |
485 | int rc; | |
486 | ||
487 | rtte = (unsigned long *) origin; | |
488 | rtte += (addr & _REGION3_INDEX) >> _REGION3_SHIFT; | |
489 | do { | |
490 | next = base_region3_addr_end(addr, end); | |
491 | if (*rtte & _REGION_ENTRY_INVALID) { | |
492 | if (!alloc) | |
493 | continue; | |
494 | table = base_crst_alloc(_SEGMENT_ENTRY_EMPTY); | |
495 | if (!table) | |
496 | return -ENOMEM; | |
497 | *rtte = table | _REGION3_ENTRY; | |
498 | } | |
499 | table = *rtte & _REGION_ENTRY_ORIGIN; | |
500 | rc = base_segment_walk(table, addr, next, alloc); | |
501 | if (rc) | |
502 | return rc; | |
503 | if (!alloc) | |
504 | base_crst_free(table); | |
505 | } while (rtte++, addr = next, addr < end); | |
506 | return 0; | |
507 | } | |
508 | ||
509 | static int base_region2_walk(unsigned long origin, unsigned long addr, | |
510 | unsigned long end, int alloc) | |
511 | { | |
512 | unsigned long *rste, next, table; | |
513 | int rc; | |
514 | ||
515 | rste = (unsigned long *) origin; | |
516 | rste += (addr & _REGION2_INDEX) >> _REGION2_SHIFT; | |
517 | do { | |
518 | next = base_region2_addr_end(addr, end); | |
519 | if (*rste & _REGION_ENTRY_INVALID) { | |
520 | if (!alloc) | |
521 | continue; | |
522 | table = base_crst_alloc(_REGION3_ENTRY_EMPTY); | |
523 | if (!table) | |
524 | return -ENOMEM; | |
525 | *rste = table | _REGION2_ENTRY; | |
526 | } | |
527 | table = *rste & _REGION_ENTRY_ORIGIN; | |
528 | rc = base_region3_walk(table, addr, next, alloc); | |
529 | if (rc) | |
530 | return rc; | |
531 | if (!alloc) | |
532 | base_crst_free(table); | |
533 | } while (rste++, addr = next, addr < end); | |
534 | return 0; | |
535 | } | |
536 | ||
537 | static int base_region1_walk(unsigned long origin, unsigned long addr, | |
538 | unsigned long end, int alloc) | |
539 | { | |
540 | unsigned long *rfte, next, table; | |
541 | int rc; | |
542 | ||
543 | rfte = (unsigned long *) origin; | |
544 | rfte += (addr & _REGION1_INDEX) >> _REGION1_SHIFT; | |
545 | do { | |
546 | next = base_region1_addr_end(addr, end); | |
547 | if (*rfte & _REGION_ENTRY_INVALID) { | |
548 | if (!alloc) | |
549 | continue; | |
550 | table = base_crst_alloc(_REGION2_ENTRY_EMPTY); | |
551 | if (!table) | |
552 | return -ENOMEM; | |
553 | *rfte = table | _REGION1_ENTRY; | |
554 | } | |
555 | table = *rfte & _REGION_ENTRY_ORIGIN; | |
556 | rc = base_region2_walk(table, addr, next, alloc); | |
557 | if (rc) | |
558 | return rc; | |
559 | if (!alloc) | |
560 | base_crst_free(table); | |
561 | } while (rfte++, addr = next, addr < end); | |
562 | return 0; | |
563 | } | |
564 | ||
565 | /** | |
566 | * base_asce_free - free asce and tables returned from base_asce_alloc() | |
567 | * @asce: asce to be freed | |
568 | * | |
569 | * Frees all region, segment, and page tables that were allocated with a | |
570 | * corresponding base_asce_alloc() call. | |
571 | */ | |
572 | void base_asce_free(unsigned long asce) | |
573 | { | |
574 | unsigned long table = asce & _ASCE_ORIGIN; | |
575 | ||
576 | if (!asce) | |
577 | return; | |
578 | switch (asce & _ASCE_TYPE_MASK) { | |
579 | case _ASCE_TYPE_SEGMENT: | |
580 | base_segment_walk(table, 0, _REGION3_SIZE, 0); | |
581 | break; | |
582 | case _ASCE_TYPE_REGION3: | |
583 | base_region3_walk(table, 0, _REGION2_SIZE, 0); | |
584 | break; | |
585 | case _ASCE_TYPE_REGION2: | |
586 | base_region2_walk(table, 0, _REGION1_SIZE, 0); | |
587 | break; | |
588 | case _ASCE_TYPE_REGION1: | |
589 | base_region1_walk(table, 0, -_PAGE_SIZE, 0); | |
590 | break; | |
591 | } | |
592 | base_crst_free(table); | |
593 | } | |
594 | ||
595 | static int base_pgt_cache_init(void) | |
596 | { | |
597 | static DEFINE_MUTEX(base_pgt_cache_mutex); | |
598 | unsigned long sz = _PAGE_TABLE_SIZE; | |
599 | ||
600 | if (base_pgt_cache) | |
601 | return 0; | |
602 | mutex_lock(&base_pgt_cache_mutex); | |
603 | if (!base_pgt_cache) | |
604 | base_pgt_cache = kmem_cache_create("base_pgt", sz, sz, 0, NULL); | |
605 | mutex_unlock(&base_pgt_cache_mutex); | |
606 | return base_pgt_cache ? 0 : -ENOMEM; | |
607 | } | |
608 | ||
609 | /** | |
610 | * base_asce_alloc - create kernel mapping without enhanced DAT features | |
611 | * @addr: virtual start address of kernel mapping | |
612 | * @num_pages: number of consecutive pages | |
613 | * | |
614 | * Generate an asce, including all required region, segment and page tables, | |
615 | * that can be used to access the virtual kernel mapping. The difference is | |
616 | * that the returned asce does not make use of any enhanced DAT features like | |
617 | * e.g. large pages. This is required for some I/O functions that pass an | |
618 | * asce, like e.g. some service call requests. | |
619 | * | |
620 | * Note: the returned asce may NEVER be attached to any cpu. It may only be | |
621 | * used for I/O requests. tlb entries that might result because the | |
622 | * asce was attached to a cpu won't be cleared. | |
623 | */ | |
624 | unsigned long base_asce_alloc(unsigned long addr, unsigned long num_pages) | |
625 | { | |
626 | unsigned long asce, table, end; | |
627 | int rc; | |
628 | ||
629 | if (base_pgt_cache_init()) | |
630 | return 0; | |
631 | end = addr + num_pages * PAGE_SIZE; | |
632 | if (end <= _REGION3_SIZE) { | |
633 | table = base_crst_alloc(_SEGMENT_ENTRY_EMPTY); | |
634 | if (!table) | |
635 | return 0; | |
636 | rc = base_segment_walk(table, addr, end, 1); | |
637 | asce = table | _ASCE_TYPE_SEGMENT | _ASCE_TABLE_LENGTH; | |
638 | } else if (end <= _REGION2_SIZE) { | |
639 | table = base_crst_alloc(_REGION3_ENTRY_EMPTY); | |
640 | if (!table) | |
641 | return 0; | |
642 | rc = base_region3_walk(table, addr, end, 1); | |
643 | asce = table | _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; | |
644 | } else if (end <= _REGION1_SIZE) { | |
645 | table = base_crst_alloc(_REGION2_ENTRY_EMPTY); | |
646 | if (!table) | |
647 | return 0; | |
648 | rc = base_region2_walk(table, addr, end, 1); | |
649 | asce = table | _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; | |
650 | } else { | |
651 | table = base_crst_alloc(_REGION1_ENTRY_EMPTY); | |
652 | if (!table) | |
653 | return 0; | |
654 | rc = base_region1_walk(table, addr, end, 1); | |
655 | asce = table | _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH; | |
656 | } | |
657 | if (rc) { | |
658 | base_asce_free(asce); | |
659 | asce = 0; | |
660 | } | |
661 | return asce; | |
662 | } |