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1/* arch/sparc64/mm/tsb.c
2 *
3 * Copyright (C) 2006, 2008 David S. Miller <davem@davemloft.net>
4 */
5
6#include <linux/kernel.h>
7#include <linux/preempt.h>
8#include <linux/slab.h>
9#include <asm/system.h>
10#include <asm/page.h>
11#include <asm/tlbflush.h>
12#include <asm/tlb.h>
13#include <asm/mmu_context.h>
14#include <asm/pgtable.h>
15#include <asm/tsb.h>
16#include <asm/oplib.h>
17
18extern struct tsb swapper_tsb[KERNEL_TSB_NENTRIES];
19
20static inline unsigned long tsb_hash(unsigned long vaddr, unsigned long hash_shift, unsigned long nentries)
21{
22 vaddr >>= hash_shift;
23 return vaddr & (nentries - 1);
24}
25
26static inline int tag_compare(unsigned long tag, unsigned long vaddr)
27{
28 return (tag == (vaddr >> 22));
29}
30
31/* TSB flushes need only occur on the processor initiating the address
32 * space modification, not on each cpu the address space has run on.
33 * Only the TLB flush needs that treatment.
34 */
35
36void flush_tsb_kernel_range(unsigned long start, unsigned long end)
37{
38 unsigned long v;
39
40 for (v = start; v < end; v += PAGE_SIZE) {
41 unsigned long hash = tsb_hash(v, PAGE_SHIFT,
42 KERNEL_TSB_NENTRIES);
43 struct tsb *ent = &swapper_tsb[hash];
44
45 if (tag_compare(ent->tag, v))
46 ent->tag = (1UL << TSB_TAG_INVALID_BIT);
47 }
48}
49
50static void __flush_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
51 unsigned long tsb, unsigned long nentries)
52{
53 unsigned long i;
54
55 for (i = 0; i < tb->tlb_nr; i++) {
56 unsigned long v = tb->vaddrs[i];
57 unsigned long tag, ent, hash;
58
59 v &= ~0x1UL;
60
61 hash = tsb_hash(v, hash_shift, nentries);
62 ent = tsb + (hash * sizeof(struct tsb));
63 tag = (v >> 22UL);
64
65 tsb_flush(ent, tag);
66 }
67}
68
69void flush_tsb_user(struct tlb_batch *tb)
70{
71 struct mm_struct *mm = tb->mm;
72 unsigned long nentries, base, flags;
73
74 spin_lock_irqsave(&mm->context.lock, flags);
75
76 base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
77 nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
78 if (tlb_type == cheetah_plus || tlb_type == hypervisor)
79 base = __pa(base);
80 __flush_tsb_one(tb, PAGE_SHIFT, base, nentries);
81
82#ifdef CONFIG_HUGETLB_PAGE
83 if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
84 base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
85 nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
86 if (tlb_type == cheetah_plus || tlb_type == hypervisor)
87 base = __pa(base);
88 __flush_tsb_one(tb, HPAGE_SHIFT, base, nentries);
89 }
90#endif
91 spin_unlock_irqrestore(&mm->context.lock, flags);
92}
93
94#if defined(CONFIG_SPARC64_PAGE_SIZE_8KB)
95#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_8K
96#define HV_PGSZ_MASK_BASE HV_PGSZ_MASK_8K
97#elif defined(CONFIG_SPARC64_PAGE_SIZE_64KB)
98#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_64K
99#define HV_PGSZ_MASK_BASE HV_PGSZ_MASK_64K
100#else
101#error Broken base page size setting...
102#endif
103
104#ifdef CONFIG_HUGETLB_PAGE
105#if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
106#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_64K
107#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_64K
108#elif defined(CONFIG_HUGETLB_PAGE_SIZE_512K)
109#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_512K
110#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_512K
111#elif defined(CONFIG_HUGETLB_PAGE_SIZE_4MB)
112#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_4MB
113#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_4MB
114#else
115#error Broken huge page size setting...
116#endif
117#endif
118
119static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_idx, unsigned long tsb_bytes)
120{
121 unsigned long tsb_reg, base, tsb_paddr;
122 unsigned long page_sz, tte;
123
124 mm->context.tsb_block[tsb_idx].tsb_nentries =
125 tsb_bytes / sizeof(struct tsb);
126
127 base = TSBMAP_BASE;
128 tte = pgprot_val(PAGE_KERNEL_LOCKED);
129 tsb_paddr = __pa(mm->context.tsb_block[tsb_idx].tsb);
130 BUG_ON(tsb_paddr & (tsb_bytes - 1UL));
131
132 /* Use the smallest page size that can map the whole TSB
133 * in one TLB entry.
134 */
135 switch (tsb_bytes) {
136 case 8192 << 0:
137 tsb_reg = 0x0UL;
138#ifdef DCACHE_ALIASING_POSSIBLE
139 base += (tsb_paddr & 8192);
140#endif
141 page_sz = 8192;
142 break;
143
144 case 8192 << 1:
145 tsb_reg = 0x1UL;
146 page_sz = 64 * 1024;
147 break;
148
149 case 8192 << 2:
150 tsb_reg = 0x2UL;
151 page_sz = 64 * 1024;
152 break;
153
154 case 8192 << 3:
155 tsb_reg = 0x3UL;
156 page_sz = 64 * 1024;
157 break;
158
159 case 8192 << 4:
160 tsb_reg = 0x4UL;
161 page_sz = 512 * 1024;
162 break;
163
164 case 8192 << 5:
165 tsb_reg = 0x5UL;
166 page_sz = 512 * 1024;
167 break;
168
169 case 8192 << 6:
170 tsb_reg = 0x6UL;
171 page_sz = 512 * 1024;
172 break;
173
174 case 8192 << 7:
175 tsb_reg = 0x7UL;
176 page_sz = 4 * 1024 * 1024;
177 break;
178
179 default:
180 printk(KERN_ERR "TSB[%s:%d]: Impossible TSB size %lu, killing process.\n",
181 current->comm, current->pid, tsb_bytes);
182 do_exit(SIGSEGV);
183 }
184 tte |= pte_sz_bits(page_sz);
185
186 if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
187 /* Physical mapping, no locked TLB entry for TSB. */
188 tsb_reg |= tsb_paddr;
189
190 mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
191 mm->context.tsb_block[tsb_idx].tsb_map_vaddr = 0;
192 mm->context.tsb_block[tsb_idx].tsb_map_pte = 0;
193 } else {
194 tsb_reg |= base;
195 tsb_reg |= (tsb_paddr & (page_sz - 1UL));
196 tte |= (tsb_paddr & ~(page_sz - 1UL));
197
198 mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
199 mm->context.tsb_block[tsb_idx].tsb_map_vaddr = base;
200 mm->context.tsb_block[tsb_idx].tsb_map_pte = tte;
201 }
202
203 /* Setup the Hypervisor TSB descriptor. */
204 if (tlb_type == hypervisor) {
205 struct hv_tsb_descr *hp = &mm->context.tsb_descr[tsb_idx];
206
207 switch (tsb_idx) {
208 case MM_TSB_BASE:
209 hp->pgsz_idx = HV_PGSZ_IDX_BASE;
210 break;
211#ifdef CONFIG_HUGETLB_PAGE
212 case MM_TSB_HUGE:
213 hp->pgsz_idx = HV_PGSZ_IDX_HUGE;
214 break;
215#endif
216 default:
217 BUG();
218 }
219 hp->assoc = 1;
220 hp->num_ttes = tsb_bytes / 16;
221 hp->ctx_idx = 0;
222 switch (tsb_idx) {
223 case MM_TSB_BASE:
224 hp->pgsz_mask = HV_PGSZ_MASK_BASE;
225 break;
226#ifdef CONFIG_HUGETLB_PAGE
227 case MM_TSB_HUGE:
228 hp->pgsz_mask = HV_PGSZ_MASK_HUGE;
229 break;
230#endif
231 default:
232 BUG();
233 }
234 hp->tsb_base = tsb_paddr;
235 hp->resv = 0;
236 }
237}
238
239struct kmem_cache *pgtable_cache __read_mostly;
240
241static struct kmem_cache *tsb_caches[8] __read_mostly;
242
243static const char *tsb_cache_names[8] = {
244 "tsb_8KB",
245 "tsb_16KB",
246 "tsb_32KB",
247 "tsb_64KB",
248 "tsb_128KB",
249 "tsb_256KB",
250 "tsb_512KB",
251 "tsb_1MB",
252};
253
254void __init pgtable_cache_init(void)
255{
256 unsigned long i;
257
258 pgtable_cache = kmem_cache_create("pgtable_cache",
259 PAGE_SIZE, PAGE_SIZE,
260 0,
261 _clear_page);
262 if (!pgtable_cache) {
263 prom_printf("pgtable_cache_init(): Could not create!\n");
264 prom_halt();
265 }
266
267 for (i = 0; i < 8; i++) {
268 unsigned long size = 8192 << i;
269 const char *name = tsb_cache_names[i];
270
271 tsb_caches[i] = kmem_cache_create(name,
272 size, size,
273 0, NULL);
274 if (!tsb_caches[i]) {
275 prom_printf("Could not create %s cache\n", name);
276 prom_halt();
277 }
278 }
279}
280
281int sysctl_tsb_ratio = -2;
282
283static unsigned long tsb_size_to_rss_limit(unsigned long new_size)
284{
285 unsigned long num_ents = (new_size / sizeof(struct tsb));
286
287 if (sysctl_tsb_ratio < 0)
288 return num_ents - (num_ents >> -sysctl_tsb_ratio);
289 else
290 return num_ents + (num_ents >> sysctl_tsb_ratio);
291}
292
293/* When the RSS of an address space exceeds tsb_rss_limit for a TSB,
294 * do_sparc64_fault() invokes this routine to try and grow it.
295 *
296 * When we reach the maximum TSB size supported, we stick ~0UL into
297 * tsb_rss_limit for that TSB so the grow checks in do_sparc64_fault()
298 * will not trigger any longer.
299 *
300 * The TSB can be anywhere from 8K to 1MB in size, in increasing powers
301 * of two. The TSB must be aligned to it's size, so f.e. a 512K TSB
302 * must be 512K aligned. It also must be physically contiguous, so we
303 * cannot use vmalloc().
304 *
305 * The idea here is to grow the TSB when the RSS of the process approaches
306 * the number of entries that the current TSB can hold at once. Currently,
307 * we trigger when the RSS hits 3/4 of the TSB capacity.
308 */
309void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
310{
311 unsigned long max_tsb_size = 1 * 1024 * 1024;
312 unsigned long new_size, old_size, flags;
313 struct tsb *old_tsb, *new_tsb;
314 unsigned long new_cache_index, old_cache_index;
315 unsigned long new_rss_limit;
316 gfp_t gfp_flags;
317
318 if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
319 max_tsb_size = (PAGE_SIZE << MAX_ORDER);
320
321 new_cache_index = 0;
322 for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) {
323 new_rss_limit = tsb_size_to_rss_limit(new_size);
324 if (new_rss_limit > rss)
325 break;
326 new_cache_index++;
327 }
328
329 if (new_size == max_tsb_size)
330 new_rss_limit = ~0UL;
331
332retry_tsb_alloc:
333 gfp_flags = GFP_KERNEL;
334 if (new_size > (PAGE_SIZE * 2))
335 gfp_flags = __GFP_NOWARN | __GFP_NORETRY;
336
337 new_tsb = kmem_cache_alloc_node(tsb_caches[new_cache_index],
338 gfp_flags, numa_node_id());
339 if (unlikely(!new_tsb)) {
340 /* Not being able to fork due to a high-order TSB
341 * allocation failure is very bad behavior. Just back
342 * down to a 0-order allocation and force no TSB
343 * growing for this address space.
344 */
345 if (mm->context.tsb_block[tsb_index].tsb == NULL &&
346 new_cache_index > 0) {
347 new_cache_index = 0;
348 new_size = 8192;
349 new_rss_limit = ~0UL;
350 goto retry_tsb_alloc;
351 }
352
353 /* If we failed on a TSB grow, we are under serious
354 * memory pressure so don't try to grow any more.
355 */
356 if (mm->context.tsb_block[tsb_index].tsb != NULL)
357 mm->context.tsb_block[tsb_index].tsb_rss_limit = ~0UL;
358 return;
359 }
360
361 /* Mark all tags as invalid. */
362 tsb_init(new_tsb, new_size);
363
364 /* Ok, we are about to commit the changes. If we are
365 * growing an existing TSB the locking is very tricky,
366 * so WATCH OUT!
367 *
368 * We have to hold mm->context.lock while committing to the
369 * new TSB, this synchronizes us with processors in
370 * flush_tsb_user() and switch_mm() for this address space.
371 *
372 * But even with that lock held, processors run asynchronously
373 * accessing the old TSB via TLB miss handling. This is OK
374 * because those actions are just propagating state from the
375 * Linux page tables into the TSB, page table mappings are not
376 * being changed. If a real fault occurs, the processor will
377 * synchronize with us when it hits flush_tsb_user(), this is
378 * also true for the case where vmscan is modifying the page
379 * tables. The only thing we need to be careful with is to
380 * skip any locked TSB entries during copy_tsb().
381 *
382 * When we finish committing to the new TSB, we have to drop
383 * the lock and ask all other cpus running this address space
384 * to run tsb_context_switch() to see the new TSB table.
385 */
386 spin_lock_irqsave(&mm->context.lock, flags);
387
388 old_tsb = mm->context.tsb_block[tsb_index].tsb;
389 old_cache_index =
390 (mm->context.tsb_block[tsb_index].tsb_reg_val & 0x7UL);
391 old_size = (mm->context.tsb_block[tsb_index].tsb_nentries *
392 sizeof(struct tsb));
393
394
395 /* Handle multiple threads trying to grow the TSB at the same time.
396 * One will get in here first, and bump the size and the RSS limit.
397 * The others will get in here next and hit this check.
398 */
399 if (unlikely(old_tsb &&
400 (rss < mm->context.tsb_block[tsb_index].tsb_rss_limit))) {
401 spin_unlock_irqrestore(&mm->context.lock, flags);
402
403 kmem_cache_free(tsb_caches[new_cache_index], new_tsb);
404 return;
405 }
406
407 mm->context.tsb_block[tsb_index].tsb_rss_limit = new_rss_limit;
408
409 if (old_tsb) {
410 extern void copy_tsb(unsigned long old_tsb_base,
411 unsigned long old_tsb_size,
412 unsigned long new_tsb_base,
413 unsigned long new_tsb_size);
414 unsigned long old_tsb_base = (unsigned long) old_tsb;
415 unsigned long new_tsb_base = (unsigned long) new_tsb;
416
417 if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
418 old_tsb_base = __pa(old_tsb_base);
419 new_tsb_base = __pa(new_tsb_base);
420 }
421 copy_tsb(old_tsb_base, old_size, new_tsb_base, new_size);
422 }
423
424 mm->context.tsb_block[tsb_index].tsb = new_tsb;
425 setup_tsb_params(mm, tsb_index, new_size);
426
427 spin_unlock_irqrestore(&mm->context.lock, flags);
428
429 /* If old_tsb is NULL, we're being invoked for the first time
430 * from init_new_context().
431 */
432 if (old_tsb) {
433 /* Reload it on the local cpu. */
434 tsb_context_switch(mm);
435
436 /* Now force other processors to do the same. */
437 preempt_disable();
438 smp_tsb_sync(mm);
439 preempt_enable();
440
441 /* Now it is safe to free the old tsb. */
442 kmem_cache_free(tsb_caches[old_cache_index], old_tsb);
443 }
444}
445
446int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
447{
448#ifdef CONFIG_HUGETLB_PAGE
449 unsigned long huge_pte_count;
450#endif
451 unsigned int i;
452
453 spin_lock_init(&mm->context.lock);
454
455 mm->context.sparc64_ctx_val = 0UL;
456
457#ifdef CONFIG_HUGETLB_PAGE
458 /* We reset it to zero because the fork() page copying
459 * will re-increment the counters as the parent PTEs are
460 * copied into the child address space.
461 */
462 huge_pte_count = mm->context.huge_pte_count;
463 mm->context.huge_pte_count = 0;
464#endif
465
466 /* copy_mm() copies over the parent's mm_struct before calling
467 * us, so we need to zero out the TSB pointer or else tsb_grow()
468 * will be confused and think there is an older TSB to free up.
469 */
470 for (i = 0; i < MM_NUM_TSBS; i++)
471 mm->context.tsb_block[i].tsb = NULL;
472
473 /* If this is fork, inherit the parent's TSB size. We would
474 * grow it to that size on the first page fault anyways.
475 */
476 tsb_grow(mm, MM_TSB_BASE, get_mm_rss(mm));
477
478#ifdef CONFIG_HUGETLB_PAGE
479 if (unlikely(huge_pte_count))
480 tsb_grow(mm, MM_TSB_HUGE, huge_pte_count);
481#endif
482
483 if (unlikely(!mm->context.tsb_block[MM_TSB_BASE].tsb))
484 return -ENOMEM;
485
486 return 0;
487}
488
489static void tsb_destroy_one(struct tsb_config *tp)
490{
491 unsigned long cache_index;
492
493 if (!tp->tsb)
494 return;
495 cache_index = tp->tsb_reg_val & 0x7UL;
496 kmem_cache_free(tsb_caches[cache_index], tp->tsb);
497 tp->tsb = NULL;
498 tp->tsb_reg_val = 0UL;
499}
500
501void destroy_context(struct mm_struct *mm)
502{
503 unsigned long flags, i;
504
505 for (i = 0; i < MM_NUM_TSBS; i++)
506 tsb_destroy_one(&mm->context.tsb_block[i]);
507
508 spin_lock_irqsave(&ctx_alloc_lock, flags);
509
510 if (CTX_VALID(mm->context)) {
511 unsigned long nr = CTX_NRBITS(mm->context);
512 mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63));
513 }
514
515 spin_unlock_irqrestore(&ctx_alloc_lock, flags);
516}
1/* arch/sparc64/mm/tsb.c
2 *
3 * Copyright (C) 2006, 2008 David S. Miller <davem@davemloft.net>
4 */
5
6#include <linux/kernel.h>
7#include <linux/preempt.h>
8#include <linux/slab.h>
9#include <asm/page.h>
10#include <asm/tlbflush.h>
11#include <asm/tlb.h>
12#include <asm/mmu_context.h>
13#include <asm/pgtable.h>
14#include <asm/tsb.h>
15#include <asm/oplib.h>
16
17extern struct tsb swapper_tsb[KERNEL_TSB_NENTRIES];
18
19static inline unsigned long tsb_hash(unsigned long vaddr, unsigned long hash_shift, unsigned long nentries)
20{
21 vaddr >>= hash_shift;
22 return vaddr & (nentries - 1);
23}
24
25static inline int tag_compare(unsigned long tag, unsigned long vaddr)
26{
27 return (tag == (vaddr >> 22));
28}
29
30/* TSB flushes need only occur on the processor initiating the address
31 * space modification, not on each cpu the address space has run on.
32 * Only the TLB flush needs that treatment.
33 */
34
35void flush_tsb_kernel_range(unsigned long start, unsigned long end)
36{
37 unsigned long v;
38
39 for (v = start; v < end; v += PAGE_SIZE) {
40 unsigned long hash = tsb_hash(v, PAGE_SHIFT,
41 KERNEL_TSB_NENTRIES);
42 struct tsb *ent = &swapper_tsb[hash];
43
44 if (tag_compare(ent->tag, v))
45 ent->tag = (1UL << TSB_TAG_INVALID_BIT);
46 }
47}
48
49static void __flush_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
50 unsigned long tsb, unsigned long nentries)
51{
52 unsigned long i;
53
54 for (i = 0; i < tb->tlb_nr; i++) {
55 unsigned long v = tb->vaddrs[i];
56 unsigned long tag, ent, hash;
57
58 v &= ~0x1UL;
59
60 hash = tsb_hash(v, hash_shift, nentries);
61 ent = tsb + (hash * sizeof(struct tsb));
62 tag = (v >> 22UL);
63
64 tsb_flush(ent, tag);
65 }
66}
67
68void flush_tsb_user(struct tlb_batch *tb)
69{
70 struct mm_struct *mm = tb->mm;
71 unsigned long nentries, base, flags;
72
73 spin_lock_irqsave(&mm->context.lock, flags);
74
75 base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
76 nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
77 if (tlb_type == cheetah_plus || tlb_type == hypervisor)
78 base = __pa(base);
79 __flush_tsb_one(tb, PAGE_SHIFT, base, nentries);
80
81#ifdef CONFIG_HUGETLB_PAGE
82 if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
83 base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
84 nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
85 if (tlb_type == cheetah_plus || tlb_type == hypervisor)
86 base = __pa(base);
87 __flush_tsb_one(tb, HPAGE_SHIFT, base, nentries);
88 }
89#endif
90 spin_unlock_irqrestore(&mm->context.lock, flags);
91}
92
93#if defined(CONFIG_SPARC64_PAGE_SIZE_8KB)
94#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_8K
95#define HV_PGSZ_MASK_BASE HV_PGSZ_MASK_8K
96#elif defined(CONFIG_SPARC64_PAGE_SIZE_64KB)
97#define HV_PGSZ_IDX_BASE HV_PGSZ_IDX_64K
98#define HV_PGSZ_MASK_BASE HV_PGSZ_MASK_64K
99#else
100#error Broken base page size setting...
101#endif
102
103#ifdef CONFIG_HUGETLB_PAGE
104#if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
105#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_64K
106#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_64K
107#elif defined(CONFIG_HUGETLB_PAGE_SIZE_512K)
108#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_512K
109#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_512K
110#elif defined(CONFIG_HUGETLB_PAGE_SIZE_4MB)
111#define HV_PGSZ_IDX_HUGE HV_PGSZ_IDX_4MB
112#define HV_PGSZ_MASK_HUGE HV_PGSZ_MASK_4MB
113#else
114#error Broken huge page size setting...
115#endif
116#endif
117
118static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_idx, unsigned long tsb_bytes)
119{
120 unsigned long tsb_reg, base, tsb_paddr;
121 unsigned long page_sz, tte;
122
123 mm->context.tsb_block[tsb_idx].tsb_nentries =
124 tsb_bytes / sizeof(struct tsb);
125
126 base = TSBMAP_BASE;
127 tte = pgprot_val(PAGE_KERNEL_LOCKED);
128 tsb_paddr = __pa(mm->context.tsb_block[tsb_idx].tsb);
129 BUG_ON(tsb_paddr & (tsb_bytes - 1UL));
130
131 /* Use the smallest page size that can map the whole TSB
132 * in one TLB entry.
133 */
134 switch (tsb_bytes) {
135 case 8192 << 0:
136 tsb_reg = 0x0UL;
137#ifdef DCACHE_ALIASING_POSSIBLE
138 base += (tsb_paddr & 8192);
139#endif
140 page_sz = 8192;
141 break;
142
143 case 8192 << 1:
144 tsb_reg = 0x1UL;
145 page_sz = 64 * 1024;
146 break;
147
148 case 8192 << 2:
149 tsb_reg = 0x2UL;
150 page_sz = 64 * 1024;
151 break;
152
153 case 8192 << 3:
154 tsb_reg = 0x3UL;
155 page_sz = 64 * 1024;
156 break;
157
158 case 8192 << 4:
159 tsb_reg = 0x4UL;
160 page_sz = 512 * 1024;
161 break;
162
163 case 8192 << 5:
164 tsb_reg = 0x5UL;
165 page_sz = 512 * 1024;
166 break;
167
168 case 8192 << 6:
169 tsb_reg = 0x6UL;
170 page_sz = 512 * 1024;
171 break;
172
173 case 8192 << 7:
174 tsb_reg = 0x7UL;
175 page_sz = 4 * 1024 * 1024;
176 break;
177
178 default:
179 printk(KERN_ERR "TSB[%s:%d]: Impossible TSB size %lu, killing process.\n",
180 current->comm, current->pid, tsb_bytes);
181 do_exit(SIGSEGV);
182 }
183 tte |= pte_sz_bits(page_sz);
184
185 if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
186 /* Physical mapping, no locked TLB entry for TSB. */
187 tsb_reg |= tsb_paddr;
188
189 mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
190 mm->context.tsb_block[tsb_idx].tsb_map_vaddr = 0;
191 mm->context.tsb_block[tsb_idx].tsb_map_pte = 0;
192 } else {
193 tsb_reg |= base;
194 tsb_reg |= (tsb_paddr & (page_sz - 1UL));
195 tte |= (tsb_paddr & ~(page_sz - 1UL));
196
197 mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
198 mm->context.tsb_block[tsb_idx].tsb_map_vaddr = base;
199 mm->context.tsb_block[tsb_idx].tsb_map_pte = tte;
200 }
201
202 /* Setup the Hypervisor TSB descriptor. */
203 if (tlb_type == hypervisor) {
204 struct hv_tsb_descr *hp = &mm->context.tsb_descr[tsb_idx];
205
206 switch (tsb_idx) {
207 case MM_TSB_BASE:
208 hp->pgsz_idx = HV_PGSZ_IDX_BASE;
209 break;
210#ifdef CONFIG_HUGETLB_PAGE
211 case MM_TSB_HUGE:
212 hp->pgsz_idx = HV_PGSZ_IDX_HUGE;
213 break;
214#endif
215 default:
216 BUG();
217 }
218 hp->assoc = 1;
219 hp->num_ttes = tsb_bytes / 16;
220 hp->ctx_idx = 0;
221 switch (tsb_idx) {
222 case MM_TSB_BASE:
223 hp->pgsz_mask = HV_PGSZ_MASK_BASE;
224 break;
225#ifdef CONFIG_HUGETLB_PAGE
226 case MM_TSB_HUGE:
227 hp->pgsz_mask = HV_PGSZ_MASK_HUGE;
228 break;
229#endif
230 default:
231 BUG();
232 }
233 hp->tsb_base = tsb_paddr;
234 hp->resv = 0;
235 }
236}
237
238struct kmem_cache *pgtable_cache __read_mostly;
239
240static struct kmem_cache *tsb_caches[8] __read_mostly;
241
242static const char *tsb_cache_names[8] = {
243 "tsb_8KB",
244 "tsb_16KB",
245 "tsb_32KB",
246 "tsb_64KB",
247 "tsb_128KB",
248 "tsb_256KB",
249 "tsb_512KB",
250 "tsb_1MB",
251};
252
253void __init pgtable_cache_init(void)
254{
255 unsigned long i;
256
257 pgtable_cache = kmem_cache_create("pgtable_cache",
258 PAGE_SIZE, PAGE_SIZE,
259 0,
260 _clear_page);
261 if (!pgtable_cache) {
262 prom_printf("pgtable_cache_init(): Could not create!\n");
263 prom_halt();
264 }
265
266 for (i = 0; i < 8; i++) {
267 unsigned long size = 8192 << i;
268 const char *name = tsb_cache_names[i];
269
270 tsb_caches[i] = kmem_cache_create(name,
271 size, size,
272 0, NULL);
273 if (!tsb_caches[i]) {
274 prom_printf("Could not create %s cache\n", name);
275 prom_halt();
276 }
277 }
278}
279
280int sysctl_tsb_ratio = -2;
281
282static unsigned long tsb_size_to_rss_limit(unsigned long new_size)
283{
284 unsigned long num_ents = (new_size / sizeof(struct tsb));
285
286 if (sysctl_tsb_ratio < 0)
287 return num_ents - (num_ents >> -sysctl_tsb_ratio);
288 else
289 return num_ents + (num_ents >> sysctl_tsb_ratio);
290}
291
292/* When the RSS of an address space exceeds tsb_rss_limit for a TSB,
293 * do_sparc64_fault() invokes this routine to try and grow it.
294 *
295 * When we reach the maximum TSB size supported, we stick ~0UL into
296 * tsb_rss_limit for that TSB so the grow checks in do_sparc64_fault()
297 * will not trigger any longer.
298 *
299 * The TSB can be anywhere from 8K to 1MB in size, in increasing powers
300 * of two. The TSB must be aligned to it's size, so f.e. a 512K TSB
301 * must be 512K aligned. It also must be physically contiguous, so we
302 * cannot use vmalloc().
303 *
304 * The idea here is to grow the TSB when the RSS of the process approaches
305 * the number of entries that the current TSB can hold at once. Currently,
306 * we trigger when the RSS hits 3/4 of the TSB capacity.
307 */
308void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
309{
310 unsigned long max_tsb_size = 1 * 1024 * 1024;
311 unsigned long new_size, old_size, flags;
312 struct tsb *old_tsb, *new_tsb;
313 unsigned long new_cache_index, old_cache_index;
314 unsigned long new_rss_limit;
315 gfp_t gfp_flags;
316
317 if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
318 max_tsb_size = (PAGE_SIZE << MAX_ORDER);
319
320 new_cache_index = 0;
321 for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) {
322 new_rss_limit = tsb_size_to_rss_limit(new_size);
323 if (new_rss_limit > rss)
324 break;
325 new_cache_index++;
326 }
327
328 if (new_size == max_tsb_size)
329 new_rss_limit = ~0UL;
330
331retry_tsb_alloc:
332 gfp_flags = GFP_KERNEL;
333 if (new_size > (PAGE_SIZE * 2))
334 gfp_flags = __GFP_NOWARN | __GFP_NORETRY;
335
336 new_tsb = kmem_cache_alloc_node(tsb_caches[new_cache_index],
337 gfp_flags, numa_node_id());
338 if (unlikely(!new_tsb)) {
339 /* Not being able to fork due to a high-order TSB
340 * allocation failure is very bad behavior. Just back
341 * down to a 0-order allocation and force no TSB
342 * growing for this address space.
343 */
344 if (mm->context.tsb_block[tsb_index].tsb == NULL &&
345 new_cache_index > 0) {
346 new_cache_index = 0;
347 new_size = 8192;
348 new_rss_limit = ~0UL;
349 goto retry_tsb_alloc;
350 }
351
352 /* If we failed on a TSB grow, we are under serious
353 * memory pressure so don't try to grow any more.
354 */
355 if (mm->context.tsb_block[tsb_index].tsb != NULL)
356 mm->context.tsb_block[tsb_index].tsb_rss_limit = ~0UL;
357 return;
358 }
359
360 /* Mark all tags as invalid. */
361 tsb_init(new_tsb, new_size);
362
363 /* Ok, we are about to commit the changes. If we are
364 * growing an existing TSB the locking is very tricky,
365 * so WATCH OUT!
366 *
367 * We have to hold mm->context.lock while committing to the
368 * new TSB, this synchronizes us with processors in
369 * flush_tsb_user() and switch_mm() for this address space.
370 *
371 * But even with that lock held, processors run asynchronously
372 * accessing the old TSB via TLB miss handling. This is OK
373 * because those actions are just propagating state from the
374 * Linux page tables into the TSB, page table mappings are not
375 * being changed. If a real fault occurs, the processor will
376 * synchronize with us when it hits flush_tsb_user(), this is
377 * also true for the case where vmscan is modifying the page
378 * tables. The only thing we need to be careful with is to
379 * skip any locked TSB entries during copy_tsb().
380 *
381 * When we finish committing to the new TSB, we have to drop
382 * the lock and ask all other cpus running this address space
383 * to run tsb_context_switch() to see the new TSB table.
384 */
385 spin_lock_irqsave(&mm->context.lock, flags);
386
387 old_tsb = mm->context.tsb_block[tsb_index].tsb;
388 old_cache_index =
389 (mm->context.tsb_block[tsb_index].tsb_reg_val & 0x7UL);
390 old_size = (mm->context.tsb_block[tsb_index].tsb_nentries *
391 sizeof(struct tsb));
392
393
394 /* Handle multiple threads trying to grow the TSB at the same time.
395 * One will get in here first, and bump the size and the RSS limit.
396 * The others will get in here next and hit this check.
397 */
398 if (unlikely(old_tsb &&
399 (rss < mm->context.tsb_block[tsb_index].tsb_rss_limit))) {
400 spin_unlock_irqrestore(&mm->context.lock, flags);
401
402 kmem_cache_free(tsb_caches[new_cache_index], new_tsb);
403 return;
404 }
405
406 mm->context.tsb_block[tsb_index].tsb_rss_limit = new_rss_limit;
407
408 if (old_tsb) {
409 extern void copy_tsb(unsigned long old_tsb_base,
410 unsigned long old_tsb_size,
411 unsigned long new_tsb_base,
412 unsigned long new_tsb_size);
413 unsigned long old_tsb_base = (unsigned long) old_tsb;
414 unsigned long new_tsb_base = (unsigned long) new_tsb;
415
416 if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
417 old_tsb_base = __pa(old_tsb_base);
418 new_tsb_base = __pa(new_tsb_base);
419 }
420 copy_tsb(old_tsb_base, old_size, new_tsb_base, new_size);
421 }
422
423 mm->context.tsb_block[tsb_index].tsb = new_tsb;
424 setup_tsb_params(mm, tsb_index, new_size);
425
426 spin_unlock_irqrestore(&mm->context.lock, flags);
427
428 /* If old_tsb is NULL, we're being invoked for the first time
429 * from init_new_context().
430 */
431 if (old_tsb) {
432 /* Reload it on the local cpu. */
433 tsb_context_switch(mm);
434
435 /* Now force other processors to do the same. */
436 preempt_disable();
437 smp_tsb_sync(mm);
438 preempt_enable();
439
440 /* Now it is safe to free the old tsb. */
441 kmem_cache_free(tsb_caches[old_cache_index], old_tsb);
442 }
443}
444
445int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
446{
447#ifdef CONFIG_HUGETLB_PAGE
448 unsigned long huge_pte_count;
449#endif
450 unsigned int i;
451
452 spin_lock_init(&mm->context.lock);
453
454 mm->context.sparc64_ctx_val = 0UL;
455
456#ifdef CONFIG_HUGETLB_PAGE
457 /* We reset it to zero because the fork() page copying
458 * will re-increment the counters as the parent PTEs are
459 * copied into the child address space.
460 */
461 huge_pte_count = mm->context.huge_pte_count;
462 mm->context.huge_pte_count = 0;
463#endif
464
465 /* copy_mm() copies over the parent's mm_struct before calling
466 * us, so we need to zero out the TSB pointer or else tsb_grow()
467 * will be confused and think there is an older TSB to free up.
468 */
469 for (i = 0; i < MM_NUM_TSBS; i++)
470 mm->context.tsb_block[i].tsb = NULL;
471
472 /* If this is fork, inherit the parent's TSB size. We would
473 * grow it to that size on the first page fault anyways.
474 */
475 tsb_grow(mm, MM_TSB_BASE, get_mm_rss(mm));
476
477#ifdef CONFIG_HUGETLB_PAGE
478 if (unlikely(huge_pte_count))
479 tsb_grow(mm, MM_TSB_HUGE, huge_pte_count);
480#endif
481
482 if (unlikely(!mm->context.tsb_block[MM_TSB_BASE].tsb))
483 return -ENOMEM;
484
485 return 0;
486}
487
488static void tsb_destroy_one(struct tsb_config *tp)
489{
490 unsigned long cache_index;
491
492 if (!tp->tsb)
493 return;
494 cache_index = tp->tsb_reg_val & 0x7UL;
495 kmem_cache_free(tsb_caches[cache_index], tp->tsb);
496 tp->tsb = NULL;
497 tp->tsb_reg_val = 0UL;
498}
499
500void destroy_context(struct mm_struct *mm)
501{
502 unsigned long flags, i;
503
504 for (i = 0; i < MM_NUM_TSBS; i++)
505 tsb_destroy_one(&mm->context.tsb_block[i]);
506
507 spin_lock_irqsave(&ctx_alloc_lock, flags);
508
509 if (CTX_VALID(mm->context)) {
510 unsigned long nr = CTX_NRBITS(mm->context);
511 mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63));
512 }
513
514 spin_unlock_irqrestore(&ctx_alloc_lock, flags);
515}