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 /* Virtual address of pfn.  */
  75 #define pfn_va(pfn)     __va(PFN_PHYS(pfn))
  76
  77 void
  78 update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
  79 {
  80         unsigned long pfn = pte_pfn(*ptep);
  81         struct page *page;
  82
  83         /* We don't have pte special.  As a result, we can be called with
  84            an invalid pfn and we don't need to flush the kernel dcache page.
  85            This occurs with FireGL card in C8000.  */
  86         if (!pfn_valid(pfn))
  87                 return;
  88
  89         page = pfn_to_page(pfn);
  90         if (page_mapping(page) && test_bit(PG_dcache_dirty, &page->flags)) {
  91                 flush_kernel_dcache_page_addr(pfn_va(pfn));
  92                 clear_bit(PG_dcache_dirty, &page->flags);
  93         } else if (parisc_requires_coherency())
  94                 flush_kernel_dcache_page_addr(pfn_va(pfn));
  95 }
  96
  97 void
  98 show_cache_info(struct seq_file *m)
  99 {
 100         char buf[32];
 101
 102         seq_printf(m, "I-cache\t\t: %ld KB\n",
 103                 cache_info.ic_size/1024 );
 104         if (cache_info.dc_loop != 1)
 105                 snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
 106         seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s)\n",
 107                 cache_info.dc_size/1024,
 108                 (cache_info.dc_conf.cc_wt ? "WT":"WB"),
 109                 (cache_info.dc_conf.cc_sh ? ", shared I/D":""),
 110                 ((cache_info.dc_loop == 1) ? "direct mapped" : buf));
 111         seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
 112                 cache_info.it_size,
 113                 cache_info.dt_size,
 114                 cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
 115         );
 116
 117 #ifndef CONFIG_PA20
 118         /* BTLB - Block TLB */
 119         if (btlb_info.max_size==0) {
 120                 seq_printf(m, "BTLB\t\t: not supported\n" );
 121         } else {
 122                 seq_printf(m,
 123                 "BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
 124                 "BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
 125                 "BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
 126                 btlb_info.max_size, (int)4096,
 127                 btlb_info.max_size>>8,
 128                 btlb_info.fixed_range_info.num_i,
 129                 btlb_info.fixed_range_info.num_d,
 130                 btlb_info.fixed_range_info.num_comb,
 131                 btlb_info.variable_range_info.num_i,
 132                 btlb_info.variable_range_info.num_d,
 133                 btlb_info.variable_range_info.num_comb
 134                 );
 135         }
 136 #endif
 137 }
 138
 139 void __init
 140 parisc_cache_init(void)
 141 {
 142         if (pdc_cache_info(&cache_info) < 0)
 143                 panic("parisc_cache_init: pdc_cache_info failed");
 144
 145 #if 0
 146         printk("ic_size %lx dc_size %lx it_size %lx\n",
 147                 cache_info.ic_size,
 148                 cache_info.dc_size,
 149                 cache_info.it_size);
 150
 151         printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
 152                 cache_info.dc_base,
 153                 cache_info.dc_stride,
 154                 cache_info.dc_count,
 155                 cache_info.dc_loop);
 156
 157         printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
 158                 *(unsigned long *) (&cache_info.dc_conf),
 159                 cache_info.dc_conf.cc_alias,
 160                 cache_info.dc_conf.cc_block,
 161                 cache_info.dc_conf.cc_line,
 162                 cache_info.dc_conf.cc_shift);
 163         printk("        wt %d sh %d cst %d hv %d\n",
 164                 cache_info.dc_conf.cc_wt,
 165                 cache_info.dc_conf.cc_sh,
 166                 cache_info.dc_conf.cc_cst,
 167                 cache_info.dc_conf.cc_hv);
 168
 169         printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
 170                 cache_info.ic_base,
 171                 cache_info.ic_stride,
 172                 cache_info.ic_count,
 173                 cache_info.ic_loop);
 174
 175         printk("IT  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx off_base 0x%lx off_stride 0x%lx off_count 0x%lx\n",
 176                 cache_info.it_sp_base,
 177                 cache_info.it_sp_stride,
 178                 cache_info.it_sp_count,
 179                 cache_info.it_loop,
 180                 cache_info.it_off_base,
 181                 cache_info.it_off_stride,
 182                 cache_info.it_off_count);
 183
 184         printk("DT  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx off_base 0x%lx off_stride 0x%lx off_count 0x%lx\n",
 185                 cache_info.dt_sp_base,
 186                 cache_info.dt_sp_stride,
 187                 cache_info.dt_sp_count,
 188                 cache_info.dt_loop,
 189                 cache_info.dt_off_base,
 190                 cache_info.dt_off_stride,
 191                 cache_info.dt_off_count);
 192
 193         printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
 194                 *(unsigned long *) (&cache_info.ic_conf),
 195                 cache_info.ic_conf.cc_alias,
 196                 cache_info.ic_conf.cc_block,
 197                 cache_info.ic_conf.cc_line,
 198                 cache_info.ic_conf.cc_shift);
 199         printk("        wt %d sh %d cst %d hv %d\n",
 200                 cache_info.ic_conf.cc_wt,
 201                 cache_info.ic_conf.cc_sh,
 202                 cache_info.ic_conf.cc_cst,
 203                 cache_info.ic_conf.cc_hv);
 204
 205         printk("D-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
 206                 cache_info.dt_conf.tc_sh,
 207                 cache_info.dt_conf.tc_page,
 208                 cache_info.dt_conf.tc_cst,
 209                 cache_info.dt_conf.tc_aid,
 210                 cache_info.dt_conf.tc_sr);
 211
 212         printk("I-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
 213                 cache_info.it_conf.tc_sh,
 214                 cache_info.it_conf.tc_page,
 215                 cache_info.it_conf.tc_cst,
 216                 cache_info.it_conf.tc_aid,
 217                 cache_info.it_conf.tc_sr);
 218 #endif
 219
 220         split_tlb = 0;
 221         if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
 222                 if (cache_info.dt_conf.tc_sh == 2)
 223                         printk(KERN_WARNING "Unexpected TLB configuration. "
 224                         "Will flush I/D separately (could be optimized).\n");
 225
 226                 split_tlb = 1;
 227         }
 228
 229         /* "New and Improved" version from Jim Hull
 230          *      (1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
 231          * The following CAFL_STRIDE is an optimized version, see
 232          * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
 233          * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
 234          */
 235 #define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
 236         dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
 237         icache_stride = CAFL_STRIDE(cache_info.ic_conf);
 238 #undef CAFL_STRIDE
 239
 240 #ifndef CONFIG_PA20
 241         if (pdc_btlb_info(&btlb_info) < 0) {
 242                 memset(&btlb_info, 0, sizeof btlb_info);
 243         }
 244 #endif
 245
 246         if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
 247                                                 PDC_MODEL_NVA_UNSUPPORTED) {
 248                 printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
 249 #if 0
 250                 panic("SMP kernel required to avoid non-equivalent aliasing");
 251 #endif
 252         }
 253 }
 254
 255 void disable_sr_hashing(void)
 256 {
 257         int srhash_type, retval;
 258         unsigned long space_bits;
 259
 260         switch (boot_cpu_data.cpu_type) {
 261         case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
 262                 BUG();
 263                 return;
 264
 265         case pcxs:
 266         case pcxt:
 267         case pcxt_:
 268                 srhash_type = SRHASH_PCXST;
 269                 break;
 270
 271         case pcxl:
 272                 srhash_type = SRHASH_PCXL;
 273                 break;
 274
 275         case pcxl2: /* pcxl2 doesn't support space register hashing */
 276                 return;
 277
 278         default: /* Currently all PA2.0 machines use the same ins. sequence */
 279                 srhash_type = SRHASH_PA20;
 280                 break;
 281         }
 282
 283         disable_sr_hashing_asm(srhash_type);
 284
 285         retval = pdc_spaceid_bits(&space_bits);
 286         /* If this procedure isn't implemented, don't panic. */
 287         if (retval < 0 && retval != PDC_BAD_OPTION)
 288                 panic("pdc_spaceid_bits call failed.\n");
 289         if (space_bits != 0)
 290                 panic("SpaceID hashing is still on!\n");
 291 }
 292
 293 static inline void
 294 __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
 295                    unsigned long physaddr)
 296 {
 297         preempt_disable();
 298         flush_dcache_page_asm(physaddr, vmaddr);
 299         if (vma->vm_flags & VM_EXEC)
 300                 flush_icache_page_asm(physaddr, vmaddr);
 301         preempt_enable();
 302 }
 303
 304 void flush_dcache_page(struct page *page)
 305 {
 306         struct address_space *mapping = page_mapping(page);
 307         struct vm_area_struct *mpnt;
 308         unsigned long offset;
 309         unsigned long addr, old_addr = 0;
 310         pgoff_t pgoff;
 311
 312         if (mapping && !mapping_mapped(mapping)) {
 313                 set_bit(PG_dcache_dirty, &page->flags);
 314                 return;
 315         }
 316
 317         flush_kernel_dcache_page(page);
 318
 319         if (!mapping)
 320                 return;
 321
 322         pgoff = page->index;
 323
 324         /* We have carefully arranged in arch_get_unmapped_area() that
 325          * *any* mappings of a file are always congruently mapped (whether
 326          * declared as MAP_PRIVATE or MAP_SHARED), so we only need
 327          * to flush one address here for them all to become coherent */
 328
 329         flush_dcache_mmap_lock(mapping);
 330         vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
 331                 offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
 332                 addr = mpnt->vm_start + offset;
 333
 334                 /* The TLB is the engine of coherence on parisc: The
 335                  * CPU is entitled to speculate any page with a TLB
 336                  * mapping, so here we kill the mapping then flush the
 337                  * page along a special flush only alias mapping.
 338                  * This guarantees that the page is no-longer in the
 339                  * cache for any process and nor may it be
 340                  * speculatively read in (until the user or kernel
 341                  * specifically accesses it, of course) */
 342
 343                 flush_tlb_page(mpnt, addr);
 344                 if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
 345                                       != (addr & (SHM_COLOUR - 1))) {
 346                         __flush_cache_page(mpnt, addr, page_to_phys(page));
 347                         if (old_addr)
 348                                 printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %pD\n", old_addr, addr, mpnt->vm_file);
 349                         old_addr = addr;
 350                 }
 351         }
 352         flush_dcache_mmap_unlock(mapping);
 353 }
 354 EXPORT_SYMBOL(flush_dcache_page);
 355
 356 /* Defined in arch/parisc/kernel/pacache.S */
 357 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
 358 EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
 359 EXPORT_SYMBOL(flush_data_cache_local);
 360 EXPORT_SYMBOL(flush_kernel_icache_range_asm);
 361
 362 #define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
 363 static unsigned long parisc_cache_flush_threshold __read_mostly = FLUSH_THRESHOLD;
 364
 365 #define FLUSH_TLB_THRESHOLD (2*1024*1024) /* 2MB initial TLB threshold */
 366 static unsigned long parisc_tlb_flush_threshold __read_mostly = FLUSH_TLB_THRESHOLD;
 367
 368 void __init parisc_setup_cache_timing(void)
 369 {
 370         unsigned long rangetime, alltime;
 371         unsigned long size, start;
 372         unsigned long threshold;
 373
 374         alltime = mfctl(16);
 375         flush_data_cache();
 376         alltime = mfctl(16) - alltime;
 377
 378         size = (unsigned long)(_end - _text);
 379         rangetime = mfctl(16);
 380         flush_kernel_dcache_range((unsigned long)_text, size);
 381         rangetime = mfctl(16) - rangetime;
 382
 383         printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
 384                 alltime, size, rangetime);
 385
 386         threshold = L1_CACHE_ALIGN(size * alltime / rangetime);
 387         if (threshold > cache_info.dc_size)
 388                 threshold = cache_info.dc_size;
 389         if (threshold)
 390                 parisc_cache_flush_threshold = threshold;
 391         printk(KERN_INFO "Cache flush threshold set to %lu KiB\n",
 392                 parisc_cache_flush_threshold/1024);
 393
 394         /* calculate TLB flush threshold */
 395
 396         /* On SMP machines, skip the TLB measure of kernel text which
 397          * has been mapped as huge pages. */
 398         if (num_online_cpus() > 1 && !parisc_requires_coherency()) {
 399                 threshold = max(cache_info.it_size, cache_info.dt_size);
 400                 threshold *= PAGE_SIZE;
 401                 threshold /= num_online_cpus();
 402                 goto set_tlb_threshold;
 403         }
 404
 405         alltime = mfctl(16);
 406         flush_tlb_all();
 407         alltime = mfctl(16) - alltime;
 408
 409         size = 0;
 410         start = (unsigned long) _text;
 411         rangetime = mfctl(16);
 412         while (start < (unsigned long) _end) {
 413                 flush_tlb_kernel_range(start, start + PAGE_SIZE);
 414                 start += PAGE_SIZE;
 415                 size += PAGE_SIZE;
 416         }
 417         rangetime = mfctl(16) - rangetime;
 418
 419         printk(KERN_DEBUG "Whole TLB flush %lu cycles, flushing %lu bytes %lu cycles\n",
 420                 alltime, size, rangetime);
 421
 422         threshold = PAGE_ALIGN(num_online_cpus() * size * alltime / rangetime);
 423
 424 set_tlb_threshold:
 425         if (threshold)
 426                 parisc_tlb_flush_threshold = threshold;
 427         printk(KERN_INFO "TLB flush threshold set to %lu KiB\n",
 428                 parisc_tlb_flush_threshold/1024);
 429 }
 430
 431 extern void purge_kernel_dcache_page_asm(unsigned long);
 432 extern void clear_user_page_asm(void *, unsigned long);
 433 extern void copy_user_page_asm(void *, void *, unsigned long);
 434
 435 void flush_kernel_dcache_page_addr(void *addr)
 436 {
 437         unsigned long flags;
 438
 439         flush_kernel_dcache_page_asm(addr);
 440         purge_tlb_start(flags);
 441         pdtlb_kernel(addr);
 442         purge_tlb_end(flags);
 443 }
 444 EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
 445
 446 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 447         struct page *pg)
 448 {
 449        /* Copy using kernel mapping.  No coherency is needed (all in
 450           kunmap) for the `to' page.  However, the `from' page needs to
 451           be flushed through a mapping equivalent to the user mapping
 452           before it can be accessed through the kernel mapping. */
 453         preempt_disable();
 454         flush_dcache_page_asm(__pa(vfrom), vaddr);
 455         preempt_enable();
 456         copy_page_asm(vto, vfrom);
 457 }
 458 EXPORT_SYMBOL(copy_user_page);
 459
 460 /* __flush_tlb_range()
 461  *
 462  * returns 1 if all TLBs were flushed.
 463  */
 464 int __flush_tlb_range(unsigned long sid, unsigned long start,
 465                       unsigned long end)
 466 {
 467         unsigned long flags, size;
 468
 469         size = (end - start);
 470         if (size >= parisc_tlb_flush_threshold) {
 471                 flush_tlb_all();
 472                 return 1;
 473         }
 474
 475         /* Purge TLB entries for small ranges using the pdtlb and
 476            pitlb instructions.  These instructions execute locally
 477            but cause a purge request to be broadcast to other TLBs.  */
 478         if (likely(!split_tlb)) {
 479                 while (start < end) {
 480                         purge_tlb_start(flags);
 481                         mtsp(sid, 1);
 482                         pdtlb(start);
 483                         purge_tlb_end(flags);
 484                         start += PAGE_SIZE;
 485                 }
 486                 return 0;
 487         }
 488
 489         /* split TLB case */
 490         while (start < end) {
 491                 purge_tlb_start(flags);
 492                 mtsp(sid, 1);
 493                 pdtlb(start);
 494                 pitlb(start);
 495                 purge_tlb_end(flags);
 496                 start += PAGE_SIZE;
 497         }
 498         return 0;
 499 }
 500
 501 static void cacheflush_h_tmp_function(void *dummy)
 502 {
 503         flush_cache_all_local();
 504 }
 505
 506 void flush_cache_all(void)
 507 {
 508         on_each_cpu(cacheflush_h_tmp_function, NULL, 1);
 509 }
 510
 511 static inline unsigned long mm_total_size(struct mm_struct *mm)
 512 {
 513         struct vm_area_struct *vma;
 514         unsigned long usize = 0;
 515
 516         for (vma = mm->mmap; vma; vma = vma->vm_next)
 517                 usize += vma->vm_end - vma->vm_start;
 518         return usize;
 519 }
 520
 521 static inline pte_t *get_ptep(pgd_t *pgd, unsigned long addr)
 522 {
 523         pte_t *ptep = NULL;
 524
 525         if (!pgd_none(*pgd)) {
 526                 pud_t *pud = pud_offset(pgd, addr);
 527                 if (!pud_none(*pud)) {
 528                         pmd_t *pmd = pmd_offset(pud, addr);
 529                         if (!pmd_none(*pmd))
 530                                 ptep = pte_offset_map(pmd, addr);
 531                 }
 532         }
 533         return ptep;
 534 }
 535
 536 void flush_cache_mm(struct mm_struct *mm)
 537 {
 538         struct vm_area_struct *vma;
 539         pgd_t *pgd;
 540
 541         /* Flushing the whole cache on each cpu takes forever on
 542            rp3440, etc.  So, avoid it if the mm isn't too big.  */
 543         if (mm_total_size(mm) >= parisc_cache_flush_threshold) {
 544                 flush_cache_all();
 545                 return;
 546         }
 547
 548         if (mm->context == mfsp(3)) {
 549                 for (vma = mm->mmap; vma; vma = vma->vm_next) {
 550                         flush_user_dcache_range_asm(vma->vm_start, vma->vm_end);
 551                         if ((vma->vm_flags & VM_EXEC) == 0)
 552                                 continue;
 553                         flush_user_icache_range_asm(vma->vm_start, vma->vm_end);
 554                 }
 555                 return;
 556         }
 557
 558         pgd = mm->pgd;
 559         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 560                 unsigned long addr;
 561
 562                 for (addr = vma->vm_start; addr < vma->vm_end;
 563                      addr += PAGE_SIZE) {
 564                         unsigned long pfn;
 565                         pte_t *ptep = get_ptep(pgd, addr);
 566                         if (!ptep)
 567                                 continue;
 568                         pfn = pte_pfn(*ptep);
 569                         if (!pfn_valid(pfn))
 570                                 continue;
 571                         __flush_cache_page(vma, addr, PFN_PHYS(pfn));
 572                 }
 573         }
 574 }
 575
 576 void
 577 flush_user_dcache_range(unsigned long start, unsigned long end)
 578 {
 579         if ((end - start) < parisc_cache_flush_threshold)
 580                 flush_user_dcache_range_asm(start,end);
 581         else
 582                 flush_data_cache();
 583 }
 584
 585 void
 586 flush_user_icache_range(unsigned long start, unsigned long end)
 587 {
 588         if ((end - start) < parisc_cache_flush_threshold)
 589                 flush_user_icache_range_asm(start,end);
 590         else
 591                 flush_instruction_cache();
 592 }
 593
 594 void flush_cache_range(struct vm_area_struct *vma,
 595                 unsigned long start, unsigned long end)
 596 {
 597         unsigned long addr;
 598         pgd_t *pgd;
 599
 600         BUG_ON(!vma->vm_mm->context);
 601
 602         if ((end - start) >= parisc_cache_flush_threshold) {
 603                 flush_cache_all();
 604                 return;
 605         }
 606
 607         if (vma->vm_mm->context == mfsp(3)) {
 608                 flush_user_dcache_range_asm(start, end);
 609                 if (vma->vm_flags & VM_EXEC)
 610                         flush_user_icache_range_asm(start, end);
 611                 return;
 612         }
 613
 614         pgd = vma->vm_mm->pgd;
 615         for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
 616                 unsigned long pfn;
 617                 pte_t *ptep = get_ptep(pgd, addr);
 618                 if (!ptep)
 619                         continue;
 620                 pfn = pte_pfn(*ptep);
 621                 if (pfn_valid(pfn))
 622                         __flush_cache_page(vma, addr, PFN_PHYS(pfn));
 623         }
 624 }
 625
 626 void
 627 flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
 628 {
 629         BUG_ON(!vma->vm_mm->context);
 630
 631         if (pfn_valid(pfn)) {
 632                 flush_tlb_page(vma, vmaddr);
 633                 __flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
 634         }
 635 }