~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/sparc/mm/tsb.c

Version: ~ [ linux-5.12-rc1 ] ~ [ linux-5.11.2 ] ~ [ linux-5.10.19 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.101 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.177 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.222 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.258 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.258 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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/pgtable.h>
 11 #include <asm/mmu_context.h>
 12 #include <asm/setup.h>
 13 #include <asm/tsb.h>
 14 #include <asm/tlb.h>
 15 #include <asm/oplib.h>
 16 
 17 extern struct tsb swapper_tsb[KERNEL_TSB_NENTRIES];
 18 
 19 static 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 
 25 static 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 
 35 void 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 
 49 static void __flush_tsb_one_entry(unsigned long tsb, unsigned long v,
 50                                   unsigned long hash_shift,
 51                                   unsigned long nentries)
 52 {
 53         unsigned long tag, ent, hash;
 54 
 55         v &= ~0x1UL;
 56         hash = tsb_hash(v, hash_shift, nentries);
 57         ent = tsb + (hash * sizeof(struct tsb));
 58         tag = (v >> 22UL);
 59 
 60         tsb_flush(ent, tag);
 61 }
 62 
 63 static void __flush_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
 64                             unsigned long tsb, unsigned long nentries)
 65 {
 66         unsigned long i;
 67 
 68         for (i = 0; i < tb->tlb_nr; i++)
 69                 __flush_tsb_one_entry(tsb, tb->vaddrs[i], hash_shift, nentries);
 70 }
 71 
 72 void flush_tsb_user(struct tlb_batch *tb)
 73 {
 74         struct mm_struct *mm = tb->mm;
 75         unsigned long nentries, base, flags;
 76 
 77         spin_lock_irqsave(&mm->context.lock, flags);
 78 
 79         base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
 80         nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
 81         if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 82                 base = __pa(base);
 83         __flush_tsb_one(tb, PAGE_SHIFT, base, nentries);
 84 
 85 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 86         if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
 87                 base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
 88                 nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
 89                 if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 90                         base = __pa(base);
 91                 __flush_tsb_one(tb, REAL_HPAGE_SHIFT, base, nentries);
 92         }
 93 #endif
 94         spin_unlock_irqrestore(&mm->context.lock, flags);
 95 }
 96 
 97 void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr)
 98 {
 99         unsigned long nentries, base, flags;
100 
101         spin_lock_irqsave(&mm->context.lock, flags);
102 
103         base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
104         nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
105         if (tlb_type == cheetah_plus || tlb_type == hypervisor)
106                 base = __pa(base);
107         __flush_tsb_one_entry(base, vaddr, PAGE_SHIFT, nentries);
108 
109 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
110         if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
111                 base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
112                 nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
113                 if (tlb_type == cheetah_plus || tlb_type == hypervisor)
114                         base = __pa(base);
115                 __flush_tsb_one_entry(base, vaddr, REAL_HPAGE_SHIFT, nentries);
116         }
117 #endif
118         spin_unlock_irqrestore(&mm->context.lock, flags);
119 }
120 
121 #define HV_PGSZ_IDX_BASE        HV_PGSZ_IDX_8K
122 #define HV_PGSZ_MASK_BASE       HV_PGSZ_MASK_8K
123 
124 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
125 #define HV_PGSZ_IDX_HUGE        HV_PGSZ_IDX_4MB
126 #define HV_PGSZ_MASK_HUGE       HV_PGSZ_MASK_4MB
127 #endif
128 
129 static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_idx, unsigned long tsb_bytes)
130 {
131         unsigned long tsb_reg, base, tsb_paddr;
132         unsigned long page_sz, tte;
133 
134         mm->context.tsb_block[tsb_idx].tsb_nentries =
135                 tsb_bytes / sizeof(struct tsb);
136 
137         switch (tsb_idx) {
138         case MM_TSB_BASE:
139                 base = TSBMAP_8K_BASE;
140                 break;
141 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
142         case MM_TSB_HUGE:
143                 base = TSBMAP_4M_BASE;
144                 break;
145 #endif
146         default:
147                 BUG();
148         }
149 
150         tte = pgprot_val(PAGE_KERNEL_LOCKED);
151         tsb_paddr = __pa(mm->context.tsb_block[tsb_idx].tsb);
152         BUG_ON(tsb_paddr & (tsb_bytes - 1UL));
153 
154         /* Use the smallest page size that can map the whole TSB
155          * in one TLB entry.
156          */
157         switch (tsb_bytes) {
158         case 8192 << 0:
159                 tsb_reg = 0x0UL;
160 #ifdef DCACHE_ALIASING_POSSIBLE
161                 base += (tsb_paddr & 8192);
162 #endif
163                 page_sz = 8192;
164                 break;
165 
166         case 8192 << 1:
167                 tsb_reg = 0x1UL;
168                 page_sz = 64 * 1024;
169                 break;
170 
171         case 8192 << 2:
172                 tsb_reg = 0x2UL;
173                 page_sz = 64 * 1024;
174                 break;
175 
176         case 8192 << 3:
177                 tsb_reg = 0x3UL;
178                 page_sz = 64 * 1024;
179                 break;
180 
181         case 8192 << 4:
182                 tsb_reg = 0x4UL;
183                 page_sz = 512 * 1024;
184                 break;
185 
186         case 8192 << 5:
187                 tsb_reg = 0x5UL;
188                 page_sz = 512 * 1024;
189                 break;
190 
191         case 8192 << 6:
192                 tsb_reg = 0x6UL;
193                 page_sz = 512 * 1024;
194                 break;
195 
196         case 8192 << 7:
197                 tsb_reg = 0x7UL;
198                 page_sz = 4 * 1024 * 1024;
199                 break;
200 
201         default:
202                 printk(KERN_ERR "TSB[%s:%d]: Impossible TSB size %lu, killing process.\n",
203                        current->comm, current->pid, tsb_bytes);
204                 do_exit(SIGSEGV);
205         }
206         tte |= pte_sz_bits(page_sz);
207 
208         if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
209                 /* Physical mapping, no locked TLB entry for TSB.  */
210                 tsb_reg |= tsb_paddr;
211 
212                 mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
213                 mm->context.tsb_block[tsb_idx].tsb_map_vaddr = 0;
214                 mm->context.tsb_block[tsb_idx].tsb_map_pte = 0;
215         } else {
216                 tsb_reg |= base;
217                 tsb_reg |= (tsb_paddr & (page_sz - 1UL));
218                 tte |= (tsb_paddr & ~(page_sz - 1UL));
219 
220                 mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
221                 mm->context.tsb_block[tsb_idx].tsb_map_vaddr = base;
222                 mm->context.tsb_block[tsb_idx].tsb_map_pte = tte;
223         }
224 
225         /* Setup the Hypervisor TSB descriptor.  */
226         if (tlb_type == hypervisor) {
227                 struct hv_tsb_descr *hp = &mm->context.tsb_descr[tsb_idx];
228 
229                 switch (tsb_idx) {
230                 case MM_TSB_BASE:
231                         hp->pgsz_idx = HV_PGSZ_IDX_BASE;
232                         break;
233 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
234                 case MM_TSB_HUGE:
235                         hp->pgsz_idx = HV_PGSZ_IDX_HUGE;
236                         break;
237 #endif
238                 default:
239                         BUG();
240                 }
241                 hp->assoc = 1;
242                 hp->num_ttes = tsb_bytes / 16;
243                 hp->ctx_idx = 0;
244                 switch (tsb_idx) {
245                 case MM_TSB_BASE:
246                         hp->pgsz_mask = HV_PGSZ_MASK_BASE;
247                         break;
248 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
249                 case MM_TSB_HUGE:
250                         hp->pgsz_mask = HV_PGSZ_MASK_HUGE;
251                         break;
252 #endif
253                 default:
254                         BUG();
255                 }
256                 hp->tsb_base = tsb_paddr;
257                 hp->resv = 0;
258         }
259 }
260 
261 struct kmem_cache *pgtable_cache __read_mostly;
262 
263 static struct kmem_cache *tsb_caches[8] __read_mostly;
264 
265 static const char *tsb_cache_names[8] = {
266         "tsb_8KB",
267         "tsb_16KB",
268         "tsb_32KB",
269         "tsb_64KB",
270         "tsb_128KB",
271         "tsb_256KB",
272         "tsb_512KB",
273         "tsb_1MB",
274 };
275 
276 void __init pgtable_cache_init(void)
277 {
278         unsigned long i;
279 
280         pgtable_cache = kmem_cache_create("pgtable_cache",
281                                           PAGE_SIZE, PAGE_SIZE,
282                                           0,
283                                           _clear_page);
284         if (!pgtable_cache) {
285                 prom_printf("pgtable_cache_init(): Could not create!\n");
286                 prom_halt();
287         }
288 
289         for (i = 0; i < ARRAY_SIZE(tsb_cache_names); i++) {
290                 unsigned long size = 8192 << i;
291                 const char *name = tsb_cache_names[i];
292 
293                 tsb_caches[i] = kmem_cache_create(name,
294                                                   size, size,
295                                                   0, NULL);
296                 if (!tsb_caches[i]) {
297                         prom_printf("Could not create %s cache\n", name);
298                         prom_halt();
299                 }
300         }
301 }
302 
303 int sysctl_tsb_ratio = -2;
304 
305 static unsigned long tsb_size_to_rss_limit(unsigned long new_size)
306 {
307         unsigned long num_ents = (new_size / sizeof(struct tsb));
308 
309         if (sysctl_tsb_ratio < 0)
310                 return num_ents - (num_ents >> -sysctl_tsb_ratio);
311         else
312                 return num_ents + (num_ents >> sysctl_tsb_ratio);
313 }
314 
315 /* When the RSS of an address space exceeds tsb_rss_limit for a TSB,
316  * do_sparc64_fault() invokes this routine to try and grow it.
317  *
318  * When we reach the maximum TSB size supported, we stick ~0UL into
319  * tsb_rss_limit for that TSB so the grow checks in do_sparc64_fault()
320  * will not trigger any longer.
321  *
322  * The TSB can be anywhere from 8K to 1MB in size, in increasing powers
323  * of two.  The TSB must be aligned to it's size, so f.e. a 512K TSB
324  * must be 512K aligned.  It also must be physically contiguous, so we
325  * cannot use vmalloc().
326  *
327  * The idea here is to grow the TSB when the RSS of the process approaches
328  * the number of entries that the current TSB can hold at once.  Currently,
329  * we trigger when the RSS hits 3/4 of the TSB capacity.
330  */
331 void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
332 {
333         unsigned long max_tsb_size = 1 * 1024 * 1024;
334         unsigned long new_size, old_size, flags;
335         struct tsb *old_tsb, *new_tsb;
336         unsigned long new_cache_index, old_cache_index;
337         unsigned long new_rss_limit;
338         gfp_t gfp_flags;
339 
340         if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
341                 max_tsb_size = (PAGE_SIZE << MAX_ORDER);
342 
343         new_cache_index = 0;
344         for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) {
345                 new_rss_limit = tsb_size_to_rss_limit(new_size);
346                 if (new_rss_limit > rss)
347                         break;
348                 new_cache_index++;
349         }
350 
351         if (new_size == max_tsb_size)
352                 new_rss_limit = ~0UL;
353 
354 retry_tsb_alloc:
355         gfp_flags = GFP_KERNEL;
356         if (new_size > (PAGE_SIZE * 2))
357                 gfp_flags |= __GFP_NOWARN | __GFP_NORETRY;
358 
359         new_tsb = kmem_cache_alloc_node(tsb_caches[new_cache_index],
360                                         gfp_flags, numa_node_id());
361         if (unlikely(!new_tsb)) {
362                 /* Not being able to fork due to a high-order TSB
363                  * allocation failure is very bad behavior.  Just back
364                  * down to a 0-order allocation and force no TSB
365                  * growing for this address space.
366                  */
367                 if (mm->context.tsb_block[tsb_index].tsb == NULL &&
368                     new_cache_index > 0) {
369                         new_cache_index = 0;
370                         new_size = 8192;
371                         new_rss_limit = ~0UL;
372                         goto retry_tsb_alloc;
373                 }
374 
375                 /* If we failed on a TSB grow, we are under serious
376                  * memory pressure so don't try to grow any more.
377                  */
378                 if (mm->context.tsb_block[tsb_index].tsb != NULL)
379                         mm->context.tsb_block[tsb_index].tsb_rss_limit = ~0UL;
380                 return;
381         }
382 
383         /* Mark all tags as invalid.  */
384         tsb_init(new_tsb, new_size);
385 
386         /* Ok, we are about to commit the changes.  If we are
387          * growing an existing TSB the locking is very tricky,
388          * so WATCH OUT!
389          *
390          * We have to hold mm->context.lock while committing to the
391          * new TSB, this synchronizes us with processors in
392          * flush_tsb_user() and switch_mm() for this address space.
393          *
394          * But even with that lock held, processors run asynchronously
395          * accessing the old TSB via TLB miss handling.  This is OK
396          * because those actions are just propagating state from the
397          * Linux page tables into the TSB, page table mappings are not
398          * being changed.  If a real fault occurs, the processor will
399          * synchronize with us when it hits flush_tsb_user(), this is
400          * also true for the case where vmscan is modifying the page
401          * tables.  The only thing we need to be careful with is to
402          * skip any locked TSB entries during copy_tsb().
403          *
404          * When we finish committing to the new TSB, we have to drop
405          * the lock and ask all other cpus running this address space
406          * to run tsb_context_switch() to see the new TSB table.
407          */
408         spin_lock_irqsave(&mm->context.lock, flags);
409 
410         old_tsb = mm->context.tsb_block[tsb_index].tsb;
411         old_cache_index =
412                 (mm->context.tsb_block[tsb_index].tsb_reg_val & 0x7UL);
413         old_size = (mm->context.tsb_block[tsb_index].tsb_nentries *
414                     sizeof(struct tsb));
415 
416 
417         /* Handle multiple threads trying to grow the TSB at the same time.
418          * One will get in here first, and bump the size and the RSS limit.
419          * The others will get in here next and hit this check.
420          */
421         if (unlikely(old_tsb &&
422                      (rss < mm->context.tsb_block[tsb_index].tsb_rss_limit))) {
423                 spin_unlock_irqrestore(&mm->context.lock, flags);
424 
425                 kmem_cache_free(tsb_caches[new_cache_index], new_tsb);
426                 return;
427         }
428 
429         mm->context.tsb_block[tsb_index].tsb_rss_limit = new_rss_limit;
430 
431         if (old_tsb) {
432                 extern void copy_tsb(unsigned long old_tsb_base,
433                                      unsigned long old_tsb_size,
434                                      unsigned long new_tsb_base,
435                                      unsigned long new_tsb_size);
436                 unsigned long old_tsb_base = (unsigned long) old_tsb;
437                 unsigned long new_tsb_base = (unsigned long) new_tsb;
438 
439                 if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
440                         old_tsb_base = __pa(old_tsb_base);
441                         new_tsb_base = __pa(new_tsb_base);
442                 }
443                 copy_tsb(old_tsb_base, old_size, new_tsb_base, new_size);
444         }
445 
446         mm->context.tsb_block[tsb_index].tsb = new_tsb;
447         setup_tsb_params(mm, tsb_index, new_size);
448 
449         spin_unlock_irqrestore(&mm->context.lock, flags);
450 
451         /* If old_tsb is NULL, we're being invoked for the first time
452          * from init_new_context().
453          */
454         if (old_tsb) {
455                 /* Reload it on the local cpu.  */
456                 tsb_context_switch(mm);
457 
458                 /* Now force other processors to do the same.  */
459                 preempt_disable();
460                 smp_tsb_sync(mm);
461                 preempt_enable();
462 
463                 /* Now it is safe to free the old tsb.  */
464                 kmem_cache_free(tsb_caches[old_cache_index], old_tsb);
465         }
466 }
467 
468 int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
469 {
470 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
471         unsigned long huge_pte_count;
472 #endif
473         unsigned int i;
474 
475         spin_lock_init(&mm->context.lock);
476 
477         mm->context.sparc64_ctx_val = 0UL;
478 
479 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
480         /* We reset it to zero because the fork() page copying
481          * will re-increment the counters as the parent PTEs are
482          * copied into the child address space.
483          */
484         huge_pte_count = mm->context.huge_pte_count;
485         mm->context.huge_pte_count = 0;
486 #endif
487 
488         /* copy_mm() copies over the parent's mm_struct before calling
489          * us, so we need to zero out the TSB pointer or else tsb_grow()
490          * will be confused and think there is an older TSB to free up.
491          */
492         for (i = 0; i < MM_NUM_TSBS; i++)
493                 mm->context.tsb_block[i].tsb = NULL;
494 
495         /* If this is fork, inherit the parent's TSB size.  We would
496          * grow it to that size on the first page fault anyways.
497          */
498         tsb_grow(mm, MM_TSB_BASE, get_mm_rss(mm));
499 
500 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
501         if (unlikely(huge_pte_count))
502                 tsb_grow(mm, MM_TSB_HUGE, huge_pte_count);
503 #endif
504 
505         if (unlikely(!mm->context.tsb_block[MM_TSB_BASE].tsb))
506                 return -ENOMEM;
507 
508         return 0;
509 }
510 
511 static void tsb_destroy_one(struct tsb_config *tp)
512 {
513         unsigned long cache_index;
514 
515         if (!tp->tsb)
516                 return;
517         cache_index = tp->tsb_reg_val & 0x7UL;
518         kmem_cache_free(tsb_caches[cache_index], tp->tsb);
519         tp->tsb = NULL;
520         tp->tsb_reg_val = 0UL;
521 }
522 
523 void destroy_context(struct mm_struct *mm)
524 {
525         unsigned long flags, i;
526 
527         for (i = 0; i < MM_NUM_TSBS; i++)
528                 tsb_destroy_one(&mm->context.tsb_block[i]);
529 
530         spin_lock_irqsave(&ctx_alloc_lock, flags);
531 
532         if (CTX_VALID(mm->context)) {
533                 unsigned long nr = CTX_NRBITS(mm->context);
534                 mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63));
535         }
536 
537         spin_unlock_irqrestore(&ctx_alloc_lock, flags);
538 }
539 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp