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parisc: fixes and cleanups in page cache flushing (1/4)
[~andy/linux] / arch / parisc / kernel / cache.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1999-2006 Helge Deller <deller@gmx.de> (07-13-1999)
7  * Copyright (C) 1999 SuSE GmbH Nuernberg
8  * Copyright (C) 2000 Philipp Rumpf (prumpf@tux.org)
9  *
10  * Cache and TLB management
11  *
12  */
13  
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/module.h>
18 #include <linux/seq_file.h>
19 #include <linux/pagemap.h>
20 #include <linux/sched.h>
21 #include <asm/pdc.h>
22 #include <asm/cache.h>
23 #include <asm/cacheflush.h>
24 #include <asm/tlbflush.h>
25 #include <asm/page.h>
26 #include <asm/pgalloc.h>
27 #include <asm/processor.h>
28 #include <asm/sections.h>
29 #include <asm/shmparam.h>
30
31 int split_tlb __read_mostly;
32 int dcache_stride __read_mostly;
33 int icache_stride __read_mostly;
34 EXPORT_SYMBOL(dcache_stride);
35
36 void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
37 EXPORT_SYMBOL(flush_dcache_page_asm);
38 void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
39
40
41 /* On some machines (e.g. ones with the Merced bus), there can be
42  * only a single PxTLB broadcast at a time; this must be guaranteed
43  * by software.  We put a spinlock around all TLB flushes  to
44  * ensure this.
45  */
46 DEFINE_SPINLOCK(pa_tlb_lock);
47
48 struct pdc_cache_info cache_info __read_mostly;
49 #ifndef CONFIG_PA20
50 static struct pdc_btlb_info btlb_info __read_mostly;
51 #endif
52
53 #ifdef CONFIG_SMP
54 void
55 flush_data_cache(void)
56 {
57         on_each_cpu(flush_data_cache_local, NULL, 1);
58 }
59 void 
60 flush_instruction_cache(void)
61 {
62         on_each_cpu(flush_instruction_cache_local, NULL, 1);
63 }
64 #endif
65
66 void
67 flush_cache_all_local(void)
68 {
69         flush_instruction_cache_local(NULL);
70         flush_data_cache_local(NULL);
71 }
72 EXPORT_SYMBOL(flush_cache_all_local);
73
74 void
75 update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
76 {
77         struct page *page = pte_page(*ptep);
78
79         if (pfn_valid(page_to_pfn(page)) && page_mapping(page) &&
80             test_bit(PG_dcache_dirty, &page->flags)) {
81
82                 flush_kernel_dcache_page(page);
83                 clear_bit(PG_dcache_dirty, &page->flags);
84         } else if (parisc_requires_coherency())
85                 flush_kernel_dcache_page(page);
86 }
87
88 void
89 show_cache_info(struct seq_file *m)
90 {
91         char buf[32];
92
93         seq_printf(m, "I-cache\t\t: %ld KB\n", 
94                 cache_info.ic_size/1024 );
95         if (cache_info.dc_loop != 1)
96                 snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
97         seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s)\n",
98                 cache_info.dc_size/1024,
99                 (cache_info.dc_conf.cc_wt ? "WT":"WB"),
100                 (cache_info.dc_conf.cc_sh ? ", shared I/D":""),
101                 ((cache_info.dc_loop == 1) ? "direct mapped" : buf));
102         seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
103                 cache_info.it_size,
104                 cache_info.dt_size,
105                 cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
106         );
107                 
108 #ifndef CONFIG_PA20
109         /* BTLB - Block TLB */
110         if (btlb_info.max_size==0) {
111                 seq_printf(m, "BTLB\t\t: not supported\n" );
112         } else {
113                 seq_printf(m, 
114                 "BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
115                 "BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
116                 "BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
117                 btlb_info.max_size, (int)4096,
118                 btlb_info.max_size>>8,
119                 btlb_info.fixed_range_info.num_i,
120                 btlb_info.fixed_range_info.num_d,
121                 btlb_info.fixed_range_info.num_comb, 
122                 btlb_info.variable_range_info.num_i,
123                 btlb_info.variable_range_info.num_d,
124                 btlb_info.variable_range_info.num_comb
125                 );
126         }
127 #endif
128 }
129
130 void __init 
131 parisc_cache_init(void)
132 {
133         if (pdc_cache_info(&cache_info) < 0)
134                 panic("parisc_cache_init: pdc_cache_info failed");
135
136 #if 0
137         printk("ic_size %lx dc_size %lx it_size %lx\n",
138                 cache_info.ic_size,
139                 cache_info.dc_size,
140                 cache_info.it_size);
141
142         printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
143                 cache_info.dc_base,
144                 cache_info.dc_stride,
145                 cache_info.dc_count,
146                 cache_info.dc_loop);
147
148         printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
149                 *(unsigned long *) (&cache_info.dc_conf),
150                 cache_info.dc_conf.cc_alias,
151                 cache_info.dc_conf.cc_block,
152                 cache_info.dc_conf.cc_line,
153                 cache_info.dc_conf.cc_shift);
154         printk("        wt %d sh %d cst %d hv %d\n",
155                 cache_info.dc_conf.cc_wt,
156                 cache_info.dc_conf.cc_sh,
157                 cache_info.dc_conf.cc_cst,
158                 cache_info.dc_conf.cc_hv);
159
160         printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
161                 cache_info.ic_base,
162                 cache_info.ic_stride,
163                 cache_info.ic_count,
164                 cache_info.ic_loop);
165
166         printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
167                 *(unsigned long *) (&cache_info.ic_conf),
168                 cache_info.ic_conf.cc_alias,
169                 cache_info.ic_conf.cc_block,
170                 cache_info.ic_conf.cc_line,
171                 cache_info.ic_conf.cc_shift);
172         printk("        wt %d sh %d cst %d hv %d\n",
173                 cache_info.ic_conf.cc_wt,
174                 cache_info.ic_conf.cc_sh,
175                 cache_info.ic_conf.cc_cst,
176                 cache_info.ic_conf.cc_hv);
177
178         printk("D-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
179                 cache_info.dt_conf.tc_sh,
180                 cache_info.dt_conf.tc_page,
181                 cache_info.dt_conf.tc_cst,
182                 cache_info.dt_conf.tc_aid,
183                 cache_info.dt_conf.tc_pad1);
184
185         printk("I-TLB conf: sh %d page %d cst %d aid %d pad1 %d\n",
186                 cache_info.it_conf.tc_sh,
187                 cache_info.it_conf.tc_page,
188                 cache_info.it_conf.tc_cst,
189                 cache_info.it_conf.tc_aid,
190                 cache_info.it_conf.tc_pad1);
191 #endif
192
193         split_tlb = 0;
194         if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
195                 if (cache_info.dt_conf.tc_sh == 2)
196                         printk(KERN_WARNING "Unexpected TLB configuration. "
197                         "Will flush I/D separately (could be optimized).\n");
198
199                 split_tlb = 1;
200         }
201
202         /* "New and Improved" version from Jim Hull 
203          *      (1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
204          * The following CAFL_STRIDE is an optimized version, see
205          * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
206          * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
207          */
208 #define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
209         dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
210         icache_stride = CAFL_STRIDE(cache_info.ic_conf);
211 #undef CAFL_STRIDE
212
213 #ifndef CONFIG_PA20
214         if (pdc_btlb_info(&btlb_info) < 0) {
215                 memset(&btlb_info, 0, sizeof btlb_info);
216         }
217 #endif
218
219         if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
220                                                 PDC_MODEL_NVA_UNSUPPORTED) {
221                 printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
222 #if 0
223                 panic("SMP kernel required to avoid non-equivalent aliasing");
224 #endif
225         }
226 }
227
228 void disable_sr_hashing(void)
229 {
230         int srhash_type, retval;
231         unsigned long space_bits;
232
233         switch (boot_cpu_data.cpu_type) {
234         case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
235                 BUG();
236                 return;
237
238         case pcxs:
239         case pcxt:
240         case pcxt_:
241                 srhash_type = SRHASH_PCXST;
242                 break;
243
244         case pcxl:
245                 srhash_type = SRHASH_PCXL;
246                 break;
247
248         case pcxl2: /* pcxl2 doesn't support space register hashing */
249                 return;
250
251         default: /* Currently all PA2.0 machines use the same ins. sequence */
252                 srhash_type = SRHASH_PA20;
253                 break;
254         }
255
256         disable_sr_hashing_asm(srhash_type);
257
258         retval = pdc_spaceid_bits(&space_bits);
259         /* If this procedure isn't implemented, don't panic. */
260         if (retval < 0 && retval != PDC_BAD_OPTION)
261                 panic("pdc_spaceid_bits call failed.\n");
262         if (space_bits != 0)
263                 panic("SpaceID hashing is still on!\n");
264 }
265
266 static inline void
267 __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
268                    unsigned long physaddr)
269 {
270         flush_dcache_page_asm(physaddr, vmaddr);
271         if (vma->vm_flags & VM_EXEC)
272                 flush_icache_page_asm(physaddr, vmaddr);
273 }
274
275 void flush_dcache_page(struct page *page)
276 {
277         struct address_space *mapping = page_mapping(page);
278         struct vm_area_struct *mpnt;
279         unsigned long offset;
280         unsigned long addr, old_addr = 0;
281         pgoff_t pgoff;
282
283         if (mapping && !mapping_mapped(mapping)) {
284                 set_bit(PG_dcache_dirty, &page->flags);
285                 return;
286         }
287
288         flush_kernel_dcache_page(page);
289
290         if (!mapping)
291                 return;
292
293         pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
294
295         /* We have carefully arranged in arch_get_unmapped_area() that
296          * *any* mappings of a file are always congruently mapped (whether
297          * declared as MAP_PRIVATE or MAP_SHARED), so we only need
298          * to flush one address here for them all to become coherent */
299
300         flush_dcache_mmap_lock(mapping);
301         vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
302                 offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
303                 addr = mpnt->vm_start + offset;
304
305                 /* The TLB is the engine of coherence on parisc: The
306                  * CPU is entitled to speculate any page with a TLB
307                  * mapping, so here we kill the mapping then flush the
308                  * page along a special flush only alias mapping.
309                  * This guarantees that the page is no-longer in the
310                  * cache for any process and nor may it be
311                  * speculatively read in (until the user or kernel
312                  * specifically accesses it, of course) */
313
314                 flush_tlb_page(mpnt, addr);
315                 if (old_addr == 0 || (old_addr & (SHMLBA - 1)) != (addr & (SHMLBA - 1))) {
316                         __flush_cache_page(mpnt, addr, page_to_phys(page));
317                         if (old_addr)
318                                 printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %s\n", old_addr, addr, mpnt->vm_file ? (char *)mpnt->vm_file->f_path.dentry->d_name.name : "(null)");
319                         old_addr = addr;
320                 }
321         }
322         flush_dcache_mmap_unlock(mapping);
323 }
324 EXPORT_SYMBOL(flush_dcache_page);
325
326 /* Defined in arch/parisc/kernel/pacache.S */
327 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
328 EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
329 EXPORT_SYMBOL(flush_data_cache_local);
330 EXPORT_SYMBOL(flush_kernel_icache_range_asm);
331
332 #define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
333 int parisc_cache_flush_threshold __read_mostly = FLUSH_THRESHOLD;
334
335 void __init parisc_setup_cache_timing(void)
336 {
337         unsigned long rangetime, alltime;
338         unsigned long size;
339
340         alltime = mfctl(16);
341         flush_data_cache();
342         alltime = mfctl(16) - alltime;
343
344         size = (unsigned long)(_end - _text);
345         rangetime = mfctl(16);
346         flush_kernel_dcache_range((unsigned long)_text, size);
347         rangetime = mfctl(16) - rangetime;
348
349         printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
350                 alltime, size, rangetime);
351
352         /* Racy, but if we see an intermediate value, it's ok too... */
353         parisc_cache_flush_threshold = size * alltime / rangetime;
354
355         parisc_cache_flush_threshold = (parisc_cache_flush_threshold + L1_CACHE_BYTES - 1) &~ (L1_CACHE_BYTES - 1); 
356         if (!parisc_cache_flush_threshold)
357                 parisc_cache_flush_threshold = FLUSH_THRESHOLD;
358
359         if (parisc_cache_flush_threshold > cache_info.dc_size)
360                 parisc_cache_flush_threshold = cache_info.dc_size;
361
362         printk(KERN_INFO "Setting cache flush threshold to %x (%d CPUs online)\n", parisc_cache_flush_threshold, num_online_cpus());
363 }
364
365 extern void purge_kernel_dcache_page_asm(unsigned long);
366 extern void clear_user_page_asm(void *, unsigned long);
367 extern void copy_user_page_asm(void *, void *, unsigned long);
368
369 void flush_kernel_dcache_page_addr(void *addr)
370 {
371         unsigned long flags;
372
373         flush_kernel_dcache_page_asm(addr);
374         purge_tlb_start(flags);
375         pdtlb_kernel(addr);
376         purge_tlb_end(flags);
377 }
378 EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
379
380 void clear_user_page(void *vto, unsigned long vaddr, struct page *page)
381 {
382         clear_page_asm(vto);
383         if (!parisc_requires_coherency())
384                 flush_kernel_dcache_page_asm(vto);
385 }
386 EXPORT_SYMBOL(clear_user_page);
387
388 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
389         struct page *pg)
390 {
391         /* Copy using kernel mapping.  No coherency is needed
392            (all in kmap/kunmap) on machines that don't support
393            non-equivalent aliasing.  However, the `from' page
394            needs to be flushed before it can be accessed through
395            the kernel mapping. */
396         preempt_disable();
397         flush_dcache_page_asm(__pa(vfrom), vaddr);
398         preempt_enable();
399         copy_page_asm(vto, vfrom);
400         if (!parisc_requires_coherency())
401                 flush_kernel_dcache_page_asm(vto);
402 }
403 EXPORT_SYMBOL(copy_user_page);
404
405 #ifdef CONFIG_PA8X00
406
407 void kunmap_parisc(void *addr)
408 {
409         if (parisc_requires_coherency())
410                 flush_kernel_dcache_page_addr(addr);
411 }
412 EXPORT_SYMBOL(kunmap_parisc);
413 #endif
414
415 void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
416 {
417         unsigned long flags;
418
419         /* Note: purge_tlb_entries can be called at startup with
420            no context.  */
421
422         /* Disable preemption while we play with %sr1.  */
423         preempt_disable();
424         mtsp(mm->context, 1);
425         purge_tlb_start(flags);
426         pdtlb(addr);
427         pitlb(addr);
428         purge_tlb_end(flags);
429         preempt_enable();
430 }
431 EXPORT_SYMBOL(purge_tlb_entries);
432
433 void __flush_tlb_range(unsigned long sid, unsigned long start,
434                        unsigned long end)
435 {
436         unsigned long npages;
437
438         npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
439         if (npages >= 512)  /* 2MB of space: arbitrary, should be tuned */
440                 flush_tlb_all();
441         else {
442                 unsigned long flags;
443
444                 mtsp(sid, 1);
445                 purge_tlb_start(flags);
446                 if (split_tlb) {
447                         while (npages--) {
448                                 pdtlb(start);
449                                 pitlb(start);
450                                 start += PAGE_SIZE;
451                         }
452                 } else {
453                         while (npages--) {
454                                 pdtlb(start);
455                                 start += PAGE_SIZE;
456                         }
457                 }
458                 purge_tlb_end(flags);
459         }
460 }
461
462 static void cacheflush_h_tmp_function(void *dummy)
463 {
464         flush_cache_all_local();
465 }
466
467 void flush_cache_all(void)
468 {
469         on_each_cpu(cacheflush_h_tmp_function, NULL, 1);
470 }
471
472 void flush_cache_mm(struct mm_struct *mm)
473 {
474 #ifdef CONFIG_SMP
475         flush_cache_all();
476 #else
477         flush_cache_all_local();
478 #endif
479 }
480
481 void
482 flush_user_dcache_range(unsigned long start, unsigned long end)
483 {
484         if ((end - start) < parisc_cache_flush_threshold)
485                 flush_user_dcache_range_asm(start,end);
486         else
487                 flush_data_cache();
488 }
489
490 void
491 flush_user_icache_range(unsigned long start, unsigned long end)
492 {
493         if ((end - start) < parisc_cache_flush_threshold)
494                 flush_user_icache_range_asm(start,end);
495         else
496                 flush_instruction_cache();
497 }
498
499
500 void flush_cache_range(struct vm_area_struct *vma,
501                 unsigned long start, unsigned long end)
502 {
503         int sr3;
504
505         BUG_ON(!vma->vm_mm->context);
506
507         sr3 = mfsp(3);
508         if (vma->vm_mm->context == sr3) {
509                 flush_user_dcache_range(start,end);
510                 flush_user_icache_range(start,end);
511         } else {
512                 flush_cache_all();
513         }
514 }
515
516 void
517 flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
518 {
519         BUG_ON(!vma->vm_mm->context);
520
521         flush_tlb_page(vma, vmaddr);
522         __flush_cache_page(vma, vmaddr, page_to_phys(pfn_to_page(pfn)));
523
524 }