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   1 /* $Id: cache.c,v 1.4 2000/01/25 00:11:38 prumpf Exp $
   2  *
   3  * This file is subject to the terms and conditions of the GNU General Public
   4  * License.  See the file "COPYING" in the main directory of this archive
   5  * for more details.
   6  *
   7  * Copyright (C) 1999-2006 Helge Deller <deller@gmx.de> (07-13-1999)
   8  * Copyright (C) 1999 SuSE GmbH Nuernberg
   9  * Copyright (C) 2000 Philipp Rumpf (prumpf@tux.org)
  10  *
  11  * Cache and TLB management
  12  *
  13  */
  14
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/mm.h>
  18 #include <linux/module.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/sched.h>
  22 #include <asm/pdc.h>
  23 #include <asm/cache.h>
  24 #include <asm/cacheflush.h>
  25 #include <asm/tlbflush.h>
  26 #include <asm/system.h>
  27 #include <asm/page.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/processor.h>
  30 #include <asm/sections.h>
  31
  32 int split_tlb __read_mostly;
  33 int dcache_stride __read_mostly;
  34 int icache_stride __read_mostly;
  35 EXPORT_SYMBOL(dcache_stride);
  36
  37
  38 /* On some machines (e.g. ones with the Merced bus), there can be
  39  * only a single PxTLB broadcast at a time; this must be guaranteed
  40  * by software.  We put a spinlock around all TLB flushes  to
  41  * ensure this.
  42  */
  43 DEFINE_SPINLOCK(pa_tlb_lock);
  44
  45 struct pdc_cache_info cache_info __read_mostly;
  46 #ifndef CONFIG_PA20
  47 static struct pdc_btlb_info btlb_info __read_mostly;
  48 #endif
  49
  50 #ifdef CONFIG_SMP
  51 void
  52 flush_data_cache(void)
  53 {
  54         on_each_cpu(flush_data_cache_local, NULL, 1);
  55 }
  56 void
  57 flush_instruction_cache(void)
  58 {
  59         on_each_cpu(flush_instruction_cache_local, NULL, 1);
  60 }
  61 #endif
  62
  63 void
  64 flush_cache_all_local(void)
  65 {
  66         flush_instruction_cache_local(NULL);
  67         flush_data_cache_local(NULL);
  68 }
  69 EXPORT_SYMBOL(flush_cache_all_local);
  70
  71 void
  72 update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t pte)
  73 {
  74         struct page *page = pte_page(pte);
  75
  76         if (pfn_valid(page_to_pfn(page)) && page_mapping(page) &&
  77             test_bit(PG_dcache_dirty, &page->flags)) {
  78
  79                 flush_kernel_dcache_page(page);
  80                 clear_bit(PG_dcache_dirty, &page->flags);
  81         } else if (parisc_requires_coherency())
  82                 flush_kernel_dcache_page(page);
  83 }
  84
  85 void
  86 show_cache_info(struct seq_file *m)
  87 {
  88         char buf[32];
  89
  90         seq_printf(m, "I-cache\t\t: %ld KB\n",
  91                 cache_info.ic_size/1024 );
  92         if (cache_info.dc_loop != 1)
  93                 snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
  94         seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s)\n",
  95                 cache_info.dc_size/1024,
  96                 (cache_info.dc_conf.cc_wt ? "WT":"WB"),
  97                 (cache_info.dc_conf.cc_sh ? ", shared I/D":""),
  98                 ((cache_info.dc_loop == 1) ? "direct mapped" : buf));
  99         seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
 100                 cache_info.it_size,
 101                 cache_info.dt_size,
 102                 cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
 103         );
 104
 105 #ifndef CONFIG_PA20
 106         /* BTLB - Block TLB */
 107         if (btlb_info.max_size==0) {
 108                 seq_printf(m, "BTLB\t\t: not supported\n" );
 109         } else {
 110                 seq_printf(m,
 111                 "BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
 112                 "BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
 113                 "BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
 114                 btlb_info.max_size, (int)4096,
 115                 btlb_info.max_size>>8,
 116                 btlb_info.fixed_range_info.num_i,
 117                 btlb_info.fixed_range_info.num_d,
 118                 btlb_info.fixed_range_info.num_comb,
 119                 btlb_info.variable_range_info.num_i,
 120                 btlb_info.variable_range_info.num_d,
 121                 btlb_info.variable_range_info.num_comb
 122                 );
 123         }
 124 #endif
 125 }
 126
 127 void __init
 128 parisc_cache_init(void)
 129 {
 130         if (pdc_cache_info(&cache_info) < 0)
 131                 panic("parisc_cache_init: pdc_cache_info failed");
 132
 133 #if 0
 134         printk("ic_size %lx dc_size %lx it_size %lx\n",
 135                 cache_info.ic_size,
 136                 cache_info.dc_size,
 137                 cache_info.it_size);
 138
 139         printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
 140                 cache_info.dc_base,
 141                 cache_info.dc_stride,
 142                 cache_info.dc_count,
 143                 cache_info.dc_loop);
 144
 145         printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
 146                 *(unsigned long *) (&cache_info.dc_conf),
 147                 cache_info.dc_conf.cc_alias,
 148                 cache_info.dc_conf.cc_block,
 149                 cache_info.dc_conf.cc_line,
 150                 cache_info.dc_conf.cc_shift);
 151         printk("        wt %d sh %d cst %d hv %d\n",
 152                 cache_info.dc_conf.cc_wt,
 153                 cache_info.dc_conf.cc_sh,
 154                 cache_info.dc_conf.cc_cst,
 155                 cache_info.dc_conf.cc_hv);
 156
 157         printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
 158                 cache_info.ic_base,
 159                 cache_info.ic_stride,
 160                 cache_info.ic_count,
 161                 cache_info.ic_loop);
 162
 163         printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
 164                 *(unsigned long *) (&cache_info.ic_conf),
 165                 cache_info.ic_conf.cc_alias,
 166                 cache_info.ic_conf.cc_block,
 167                 cache_info.ic_conf.cc_line,
 168                 cache_info.ic_conf.cc_shift);
 169         printk("        wt %d sh %d cst %d hv %d\n",
 170                 cache_info.ic_conf.cc_wt,
 171                 cache_info.ic_conf.cc_sh,
 172                 cache_info.ic_conf.cc_cst,
 173                 cache_info.ic_conf.cc_hv);
 174
 175         printk("D-TLB conf: sh %d page %d cst %d aid %d pad1 %d \n",
 176                 cache_info.dt_conf.tc_sh,
 177                 cache_info.dt_conf.tc_page,
 178                 cache_info.dt_conf.tc_cst,
 179                 cache_info.dt_conf.tc_aid,
 180                 cache_info.dt_conf.tc_pad1);
 181
 182         printk("I-TLB conf: sh %d page %d cst %d aid %d pad1 %d \n",
 183                 cache_info.it_conf.tc_sh,
 184                 cache_info.it_conf.tc_page,
 185                 cache_info.it_conf.tc_cst,
 186                 cache_info.it_conf.tc_aid,
 187                 cache_info.it_conf.tc_pad1);
 188 #endif
 189
 190         split_tlb = 0;
 191         if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
 192                 if (cache_info.dt_conf.tc_sh == 2)
 193                         printk(KERN_WARNING "Unexpected TLB configuration. "
 194                         "Will flush I/D separately (could be optimized).\n");
 195
 196                 split_tlb = 1;
 197         }
 198
 199         /* "New and Improved" version from Jim Hull
 200          *      (1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
 201          * The following CAFL_STRIDE is an optimized version, see
 202          * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
 203          * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
 204          */
 205 #define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
 206         dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
 207         icache_stride = CAFL_STRIDE(cache_info.ic_conf);
 208 #undef CAFL_STRIDE
 209
 210 #ifndef CONFIG_PA20
 211         if (pdc_btlb_info(&btlb_info) < 0) {
 212                 memset(&btlb_info, 0, sizeof btlb_info);
 213         }
 214 #endif
 215
 216         if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
 217                                                 PDC_MODEL_NVA_UNSUPPORTED) {
 218                 printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
 219 #if 0
 220                 panic("SMP kernel required to avoid non-equivalent aliasing");
 221 #endif
 222         }
 223 }
 224
 225 void disable_sr_hashing(void)
 226 {
 227         int srhash_type, retval;
 228         unsigned long space_bits;
 229
 230         switch (boot_cpu_data.cpu_type) {
 231         case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
 232                 BUG();
 233                 return;
 234
 235         case pcxs:
 236         case pcxt:
 237         case pcxt_:
 238                 srhash_type = SRHASH_PCXST;
 239                 break;
 240
 241         case pcxl:
 242                 srhash_type = SRHASH_PCXL;
 243                 break;
 244
 245         case pcxl2: /* pcxl2 doesn't support space register hashing */
 246                 return;
 247
 248         default: /* Currently all PA2.0 machines use the same ins. sequence */
 249                 srhash_type = SRHASH_PA20;
 250                 break;
 251         }
 252
 253         disable_sr_hashing_asm(srhash_type);
 254
 255         retval = pdc_spaceid_bits(&space_bits);
 256         /* If this procedure isn't implemented, don't panic. */
 257         if (retval < 0 && retval != PDC_BAD_OPTION)
 258                 panic("pdc_spaceid_bits call failed.\n");
 259         if (space_bits != 0)
 260                 panic("SpaceID hashing is still on!\n");
 261 }
 262
 263 /* Simple function to work out if we have an existing address translation
 264  * for a user space vma. */
 265 static inline int translation_exists(struct vm_area_struct *vma,
 266                                 unsigned long addr, unsigned long pfn)
 267 {
 268         pgd_t *pgd = pgd_offset(vma->vm_mm, addr);
 269         pmd_t *pmd;
 270         pte_t pte;
 271
 272         if(pgd_none(*pgd))
 273                 return 0;
 274
 275         pmd = pmd_offset(pgd, addr);
 276         if(pmd_none(*pmd) || pmd_bad(*pmd))
 277                 return 0;
 278
 279         /* We cannot take the pte lock here: flush_cache_page is usually
 280          * called with pte lock already held.  Whereas flush_dcache_page
 281          * takes flush_dcache_mmap_lock, which is lower in the hierarchy:
 282          * the vma itself is secure, but the pte might come or go racily.
 283          */
 284         pte = *pte_offset_map(pmd, addr);
 285         /* But pte_unmap() does nothing on this architecture */
 286
 287         /* Filter out coincidental file entries and swap entries */
 288         if (!(pte_val(pte) & (_PAGE_FLUSH|_PAGE_PRESENT)))
 289                 return 0;
 290
 291         return pte_pfn(pte) == pfn;
 292 }
 293
 294 /* Private function to flush a page from the cache of a non-current
 295  * process.  cr25 contains the Page Directory of the current user
 296  * process; we're going to hijack both it and the user space %sr3 to
 297  * temporarily make the non-current process current.  We have to do
 298  * this because cache flushing may cause a non-access tlb miss which
 299  * the handlers have to fill in from the pgd of the non-current
 300  * process. */
 301 static inline void
 302 flush_user_cache_page_non_current(struct vm_area_struct *vma,
 303                                   unsigned long vmaddr)
 304 {
 305         /* save the current process space and pgd */
 306         unsigned long space = mfsp(3), pgd = mfctl(25);
 307
 308         /* we don't mind taking interrupts since they may not
 309          * do anything with user space, but we can't
 310          * be preempted here */
 311         preempt_disable();
 312
 313         /* make us current */
 314         mtctl(__pa(vma->vm_mm->pgd), 25);
 315         mtsp(vma->vm_mm->context, 3);
 316
 317         flush_user_dcache_page(vmaddr);
 318         if(vma->vm_flags & VM_EXEC)
 319                 flush_user_icache_page(vmaddr);
 320
 321         /* put the old current process back */
 322         mtsp(space, 3);
 323         mtctl(pgd, 25);
 324         preempt_enable();
 325 }
 326
 327
 328 static inline void
 329 __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr)
 330 {
 331         if (likely(vma->vm_mm->context == mfsp(3))) {
 332                 flush_user_dcache_page(vmaddr);
 333                 if (vma->vm_flags & VM_EXEC)
 334                         flush_user_icache_page(vmaddr);
 335         } else {
 336                 flush_user_cache_page_non_current(vma, vmaddr);
 337         }
 338 }
 339
 340 void flush_dcache_page(struct page *page)
 341 {
 342         struct address_space *mapping = page_mapping(page);
 343         struct vm_area_struct *mpnt;
 344         struct prio_tree_iter iter;
 345         unsigned long offset;
 346         unsigned long addr;
 347         pgoff_t pgoff;
 348         unsigned long pfn = page_to_pfn(page);
 349
 350
 351         if (mapping && !mapping_mapped(mapping)) {
 352                 set_bit(PG_dcache_dirty, &page->flags);
 353                 return;
 354         }
 355
 356         flush_kernel_dcache_page(page);
 357
 358         if (!mapping)
 359                 return;
 360
 361         pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
 362
 363         /* We have carefully arranged in arch_get_unmapped_area() that
 364          * *any* mappings of a file are always congruently mapped (whether
 365          * declared as MAP_PRIVATE or MAP_SHARED), so we only need
 366          * to flush one address here for them all to become coherent */
 367
 368         flush_dcache_mmap_lock(mapping);
 369         vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
 370                 offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
 371                 addr = mpnt->vm_start + offset;
 372
 373                 /* Flush instructions produce non access tlb misses.
 374                  * On PA, we nullify these instructions rather than
 375                  * taking a page fault if the pte doesn't exist.
 376                  * This is just for speed.  If the page translation
 377                  * isn't there, there's no point exciting the
 378                  * nadtlb handler into a nullification frenzy.
 379                  *
 380                  * Make sure we really have this page: the private
 381                  * mappings may cover this area but have COW'd this
 382                  * particular page.
 383                  */
 384                 if (translation_exists(mpnt, addr, pfn)) {
 385                         __flush_cache_page(mpnt, addr);
 386                         break;
 387                 }
 388         }
 389         flush_dcache_mmap_unlock(mapping);
 390 }
 391 EXPORT_SYMBOL(flush_dcache_page);
 392
 393 /* Defined in arch/parisc/kernel/pacache.S */
 394 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
 395 EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
 396 EXPORT_SYMBOL(flush_data_cache_local);
 397 EXPORT_SYMBOL(flush_kernel_icache_range_asm);
 398
 399 void clear_user_page_asm(void *page, unsigned long vaddr)
 400 {
 401         /* This function is implemented in assembly in pacache.S */
 402         extern void __clear_user_page_asm(void *page, unsigned long vaddr);
 403
 404         purge_tlb_start();
 405         __clear_user_page_asm(page, vaddr);
 406         purge_tlb_end();
 407 }
 408
 409 #define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
 410 int parisc_cache_flush_threshold __read_mostly = FLUSH_THRESHOLD;
 411
 412 void __init parisc_setup_cache_timing(void)
 413 {
 414         unsigned long rangetime, alltime;
 415         unsigned long size;
 416
 417         alltime = mfctl(16);
 418         flush_data_cache();
 419         alltime = mfctl(16) - alltime;
 420
 421         size = (unsigned long)(_end - _text);
 422         rangetime = mfctl(16);
 423         flush_kernel_dcache_range((unsigned long)_text, size);
 424         rangetime = mfctl(16) - rangetime;
 425
 426         printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
 427                 alltime, size, rangetime);
 428
 429         /* Racy, but if we see an intermediate value, it's ok too... */
 430         parisc_cache_flush_threshold = size * alltime / rangetime;
 431
 432         parisc_cache_flush_threshold = (parisc_cache_flush_threshold + L1_CACHE_BYTES - 1) &~ (L1_CACHE_BYTES - 1);
 433         if (!parisc_cache_flush_threshold)
 434                 parisc_cache_flush_threshold = FLUSH_THRESHOLD;
 435
 436         if (parisc_cache_flush_threshold > cache_info.dc_size)
 437                 parisc_cache_flush_threshold = cache_info.dc_size;
 438
 439         printk(KERN_INFO "Setting cache flush threshold to %x (%d CPUs online)\n", parisc_cache_flush_threshold, num_online_cpus());
 440 }
 441
 442 extern void purge_kernel_dcache_page(unsigned long);
 443 extern void clear_user_page_asm(void *page, unsigned long vaddr);
 444
 445 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 446 {
 447         purge_kernel_dcache_page((unsigned long)page);
 448         purge_tlb_start();
 449         pdtlb_kernel(page);
 450         purge_tlb_end();
 451         clear_user_page_asm(page, vaddr);
 452 }
 453 EXPORT_SYMBOL(clear_user_page);
 454
 455 void flush_kernel_dcache_page_addr(void *addr)
 456 {
 457         flush_kernel_dcache_page_asm(addr);
 458         purge_tlb_start();
 459         pdtlb_kernel(addr);
 460         purge_tlb_end();
 461 }
 462 EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
 463
 464 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 465                     struct page *pg)
 466 {
 467         /* no coherency needed (all in kmap/kunmap) */
 468         copy_user_page_asm(vto, vfrom);
 469         if (!parisc_requires_coherency())
 470                 flush_kernel_dcache_page_asm(vto);
 471 }
 472 EXPORT_SYMBOL(copy_user_page);
 473
 474 #ifdef CONFIG_PA8X00
 475
 476 void kunmap_parisc(void *addr)
 477 {
 478         if (parisc_requires_coherency())
 479                 flush_kernel_dcache_page_addr(addr);
 480 }
 481 EXPORT_SYMBOL(kunmap_parisc);
 482 #endif
 483
 484 void __flush_tlb_range(unsigned long sid, unsigned long start,
 485                        unsigned long end)
 486 {
 487         unsigned long npages;
 488
 489         npages = ((end - (start & PAGE_MASK)) + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 490         if (npages >= 512)  /* 2MB of space: arbitrary, should be tuned */
 491                 flush_tlb_all();
 492         else {
 493                 mtsp(sid, 1);
 494                 purge_tlb_start();
 495                 if (split_tlb) {
 496                         while (npages--) {
 497                                 pdtlb(start);
 498                                 pitlb(start);
 499                                 start += PAGE_SIZE;
 500                         }
 501                 } else {
 502                         while (npages--) {
 503                                 pdtlb(start);
 504                                 start += PAGE_SIZE;
 505                         }
 506                 }
 507                 purge_tlb_end();
 508         }
 509 }
 510
 511 static void cacheflush_h_tmp_function(void *dummy)
 512 {
 513         flush_cache_all_local();
 514 }
 515
 516 void flush_cache_all(void)
 517 {
 518         on_each_cpu(cacheflush_h_tmp_function, NULL, 1);
 519 }
 520
 521 void flush_cache_mm(struct mm_struct *mm)
 522 {
 523 #ifdef CONFIG_SMP
 524         flush_cache_all();
 525 #else
 526         flush_cache_all_local();
 527 #endif
 528 }
 529
 530 void
 531 flush_user_dcache_range(unsigned long start, unsigned long end)
 532 {
 533         if ((end - start) < parisc_cache_flush_threshold)
 534                 flush_user_dcache_range_asm(start,end);
 535         else
 536                 flush_data_cache();
 537 }
 538
 539 void
 540 flush_user_icache_range(unsigned long start, unsigned long end)
 541 {
 542         if ((end - start) < parisc_cache_flush_threshold)
 543                 flush_user_icache_range_asm(start,end);
 544         else
 545                 flush_instruction_cache();
 546 }
 547
 548
 549 void flush_cache_range(struct vm_area_struct *vma,
 550                 unsigned long start, unsigned long end)
 551 {
 552         int sr3;
 553
 554         if (!vma->vm_mm->context) {
 555                 BUG();
 556                 return;
 557         }
 558
 559         sr3 = mfsp(3);
 560         if (vma->vm_mm->context == sr3) {
 561                 flush_user_dcache_range(start,end);
 562                 flush_user_icache_range(start,end);
 563         } else {
 564                 flush_cache_all();
 565         }
 566 }
 567
 568 void
 569 flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
 570 {
 571         BUG_ON(!vma->vm_mm->context);
 572
 573         if (likely(translation_exists(vma, vmaddr, pfn)))
 574                 __flush_cache_page(vma, vmaddr);
 575
 576 }