arch/mips/mm/tlb-r4k.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) 1996 David S. Miller (davem@davemloft.net)
   7  * Copyright (C) 1997, 1998, 1999, 2000 Ralf Baechle ralf@gnu.org
   8  * Carsten Langgaard, carstenl@mips.com
   9  * Copyright (C) 2002 MIPS Technologies, Inc.  All rights reserved.
  10  */
  11 #include <linux/cpu_pm.h>
  12 #include <linux/init.h>
  13 #include <linux/sched.h>
  14 #include <linux/smp.h>
  15 #include <linux/mm.h>
  16 #include <linux/hugetlb.h>
  17 #include <linux/export.h>
  18
  19 #include <asm/cpu.h>
  20 #include <asm/cpu-type.h>
  21 #include <asm/bootinfo.h>
  22 #include <asm/hazards.h>
  23 #include <asm/mmu_context.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/tlb.h>
  26 #include <asm/tlbmisc.h>
  27
  28 extern void build_tlb_refill_handler(void);
  29
  30 /*
  31  * LOONGSON-2 has a 4 entry itlb which is a subset of jtlb, LOONGSON-3 has
  32  * a 4 entry itlb and a 4 entry dtlb which are subsets of jtlb. Unfortunately,
  33  * itlb/dtlb are not totally transparent to software.
  34  */
  35 static inline void flush_micro_tlb(void)
  36 {
  37         switch (current_cpu_type()) {
  38         case CPU_LOONGSON2:
  39                 write_c0_diag(LOONGSON_DIAG_ITLB);
  40                 break;
  41         case CPU_LOONGSON3:
  42                 write_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB);
  43                 break;
  44         default:
  45                 break;
  46         }
  47 }
  48
  49 static inline void flush_micro_tlb_vm(struct vm_area_struct *vma)
  50 {
  51         if (vma->vm_flags & VM_EXEC)
  52                 flush_micro_tlb();
  53 }
  54
  55 void local_flush_tlb_all(void)
  56 {
  57         unsigned long flags;
  58         unsigned long old_ctx;
  59         int entry, ftlbhighset;
  60
  61         local_irq_save(flags);
  62         /* Save old context and create impossible VPN2 value */
  63         old_ctx = read_c0_entryhi();
  64         htw_stop();
  65         write_c0_entrylo0(0);
  66         write_c0_entrylo1(0);
  67
  68         entry = num_wired_entries();
  69
  70         /*
  71          * Blast 'em all away.
  72          * If there are any wired entries, fall back to iterating
  73          */
  74         if (cpu_has_tlbinv && !entry) {
  75                 if (current_cpu_data.tlbsizevtlb) {
  76                         write_c0_index(0);
  77                         mtc0_tlbw_hazard();
  78                         tlbinvf();  /* invalidate VTLB */
  79                 }
  80                 ftlbhighset = current_cpu_data.tlbsizevtlb +
  81                         current_cpu_data.tlbsizeftlbsets;
  82                 for (entry = current_cpu_data.tlbsizevtlb;
  83                      entry < ftlbhighset;
  84                      entry++) {
  85                         write_c0_index(entry);
  86                         mtc0_tlbw_hazard();
  87                         tlbinvf();  /* invalidate one FTLB set */
  88                 }
  89         } else {
  90                 while (entry < current_cpu_data.tlbsize) {
  91                         /* Make sure all entries differ. */
  92                         write_c0_entryhi(UNIQUE_ENTRYHI(entry));
  93                         write_c0_index(entry);
  94                         mtc0_tlbw_hazard();
  95                         tlb_write_indexed();
  96                         entry++;
  97                 }
  98         }
  99         tlbw_use_hazard();
 100         write_c0_entryhi(old_ctx);
 101         htw_start();
 102         flush_micro_tlb();
 103         local_irq_restore(flags);
 104 }
 105 EXPORT_SYMBOL(local_flush_tlb_all);
 106
 107 /* All entries common to a mm share an asid.  To effectively flush
 108    these entries, we just bump the asid. */
 109 void local_flush_tlb_mm(struct mm_struct *mm)
 110 {
 111         int cpu;
 112
 113         preempt_disable();
 114
 115         cpu = smp_processor_id();
 116
 117         if (cpu_context(cpu, mm) != 0) {
 118                 drop_mmu_context(mm, cpu);
 119         }
 120
 121         preempt_enable();
 122 }
 123
 124 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 125         unsigned long end)
 126 {
 127         struct mm_struct *mm = vma->vm_mm;
 128         int cpu = smp_processor_id();
 129
 130         if (cpu_context(cpu, mm) != 0) {
 131                 unsigned long size, flags;
 132
 133                 local_irq_save(flags);
 134                 start = round_down(start, PAGE_SIZE << 1);
 135                 end = round_up(end, PAGE_SIZE << 1);
 136                 size = (end - start) >> (PAGE_SHIFT + 1);
 137                 if (size <= (current_cpu_data.tlbsizeftlbsets ?
 138                              current_cpu_data.tlbsize / 8 :
 139                              current_cpu_data.tlbsize / 2)) {
 140                         int oldpid = read_c0_entryhi();
 141                         int newpid = cpu_asid(cpu, mm);
 142
 143                         htw_stop();
 144                         while (start < end) {
 145                                 int idx;
 146
 147                                 write_c0_entryhi(start | newpid);
 148                                 start += (PAGE_SIZE << 1);
 149                                 mtc0_tlbw_hazard();
 150                                 tlb_probe();
 151                                 tlb_probe_hazard();
 152                                 idx = read_c0_index();
 153                                 write_c0_entrylo0(0);
 154                                 write_c0_entrylo1(0);
 155                                 if (idx < 0)
 156                                         continue;
 157                                 /* Make sure all entries differ. */
 158                                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 159                                 mtc0_tlbw_hazard();
 160                                 tlb_write_indexed();
 161                         }
 162                         tlbw_use_hazard();
 163                         write_c0_entryhi(oldpid);
 164                         htw_start();
 165                 } else {
 166                         drop_mmu_context(mm, cpu);
 167                 }
 168                 flush_micro_tlb();
 169                 local_irq_restore(flags);
 170         }
 171 }
 172
 173 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 174 {
 175         unsigned long size, flags;
 176
 177         local_irq_save(flags);
 178         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 179         size = (size + 1) >> 1;
 180         if (size <= (current_cpu_data.tlbsizeftlbsets ?
 181                      current_cpu_data.tlbsize / 8 :
 182                      current_cpu_data.tlbsize / 2)) {
 183                 int pid = read_c0_entryhi();
 184
 185                 start &= (PAGE_MASK << 1);
 186                 end += ((PAGE_SIZE << 1) - 1);
 187                 end &= (PAGE_MASK << 1);
 188                 htw_stop();
 189
 190                 while (start < end) {
 191                         int idx;
 192
 193                         write_c0_entryhi(start);
 194                         start += (PAGE_SIZE << 1);
 195                         mtc0_tlbw_hazard();
 196                         tlb_probe();
 197                         tlb_probe_hazard();
 198                         idx = read_c0_index();
 199                         write_c0_entrylo0(0);
 200                         write_c0_entrylo1(0);
 201                         if (idx < 0)
 202                                 continue;
 203                         /* Make sure all entries differ. */
 204                         write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 205                         mtc0_tlbw_hazard();
 206                         tlb_write_indexed();
 207                 }
 208                 tlbw_use_hazard();
 209                 write_c0_entryhi(pid);
 210                 htw_start();
 211         } else {
 212                 local_flush_tlb_all();
 213         }
 214         flush_micro_tlb();
 215         local_irq_restore(flags);
 216 }
 217
 218 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 219 {
 220         int cpu = smp_processor_id();
 221
 222         if (cpu_context(cpu, vma->vm_mm) != 0) {
 223                 unsigned long flags;
 224                 int oldpid, newpid, idx;
 225
 226                 newpid = cpu_asid(cpu, vma->vm_mm);
 227                 page &= (PAGE_MASK << 1);
 228                 local_irq_save(flags);
 229                 oldpid = read_c0_entryhi();
 230                 htw_stop();
 231                 write_c0_entryhi(page | newpid);
 232                 mtc0_tlbw_hazard();
 233                 tlb_probe();
 234                 tlb_probe_hazard();
 235                 idx = read_c0_index();
 236                 write_c0_entrylo0(0);
 237                 write_c0_entrylo1(0);
 238                 if (idx < 0)
 239                         goto finish;
 240                 /* Make sure all entries differ. */
 241                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 242                 mtc0_tlbw_hazard();
 243                 tlb_write_indexed();
 244                 tlbw_use_hazard();
 245
 246         finish:
 247                 write_c0_entryhi(oldpid);
 248                 htw_start();
 249                 flush_micro_tlb_vm(vma);
 250                 local_irq_restore(flags);
 251         }
 252 }
 253
 254 /*
 255  * This one is only used for pages with the global bit set so we don't care
 256  * much about the ASID.
 257  */
 258 void local_flush_tlb_one(unsigned long page)
 259 {
 260         unsigned long flags;
 261         int oldpid, idx;
 262
 263         local_irq_save(flags);
 264         oldpid = read_c0_entryhi();
 265         htw_stop();
 266         page &= (PAGE_MASK << 1);
 267         write_c0_entryhi(page);
 268         mtc0_tlbw_hazard();
 269         tlb_probe();
 270         tlb_probe_hazard();
 271         idx = read_c0_index();
 272         write_c0_entrylo0(0);
 273         write_c0_entrylo1(0);
 274         if (idx >= 0) {
 275                 /* Make sure all entries differ. */
 276                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 277                 mtc0_tlbw_hazard();
 278                 tlb_write_indexed();
 279                 tlbw_use_hazard();
 280         }
 281         write_c0_entryhi(oldpid);
 282         htw_start();
 283         flush_micro_tlb();
 284         local_irq_restore(flags);
 285 }
 286
 287 /*
 288  * We will need multiple versions of update_mmu_cache(), one that just
 289  * updates the TLB with the new pte(s), and another which also checks
 290  * for the R4k "end of page" hardware bug and does the needy.
 291  */
 292 void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 293 {
 294         unsigned long flags;
 295         pgd_t *pgdp;
 296         pud_t *pudp;
 297         pmd_t *pmdp;
 298         pte_t *ptep;
 299         int idx, pid;
 300
 301         /*
 302          * Handle debugger faulting in for debugee.
 303          */
 304         if (current->active_mm != vma->vm_mm)
 305                 return;
 306
 307         local_irq_save(flags);
 308
 309         htw_stop();
 310         pid = read_c0_entryhi() & cpu_asid_mask(&current_cpu_data);
 311         address &= (PAGE_MASK << 1);
 312         write_c0_entryhi(address | pid);
 313         pgdp = pgd_offset(vma->vm_mm, address);
 314         mtc0_tlbw_hazard();
 315         tlb_probe();
 316         tlb_probe_hazard();
 317         pudp = pud_offset(pgdp, address);
 318         pmdp = pmd_offset(pudp, address);
 319         idx = read_c0_index();
 320 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 321         /* this could be a huge page  */
 322         if (pmd_huge(*pmdp)) {
 323                 unsigned long lo;
 324                 write_c0_pagemask(PM_HUGE_MASK);
 325                 ptep = (pte_t *)pmdp;
 326                 lo = pte_to_entrylo(pte_val(*ptep));
 327                 write_c0_entrylo0(lo);
 328                 write_c0_entrylo1(lo + (HPAGE_SIZE >> 7));
 329
 330                 mtc0_tlbw_hazard();
 331                 if (idx < 0)
 332                         tlb_write_random();
 333                 else
 334                         tlb_write_indexed();
 335                 tlbw_use_hazard();
 336                 write_c0_pagemask(PM_DEFAULT_MASK);
 337         } else
 338 #endif
 339         {
 340                 ptep = pte_offset_map(pmdp, address);
 341
 342 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 343 #ifdef CONFIG_XPA
 344                 write_c0_entrylo0(pte_to_entrylo(ptep->pte_high));
 345                 if (cpu_has_xpa)
 346                         writex_c0_entrylo0(ptep->pte_low & _PFNX_MASK);
 347                 ptep++;
 348                 write_c0_entrylo1(pte_to_entrylo(ptep->pte_high));
 349                 if (cpu_has_xpa)
 350                         writex_c0_entrylo1(ptep->pte_low & _PFNX_MASK);
 351 #else
 352                 write_c0_entrylo0(ptep->pte_high);
 353                 ptep++;
 354                 write_c0_entrylo1(ptep->pte_high);
 355 #endif
 356 #else
 357                 write_c0_entrylo0(pte_to_entrylo(pte_val(*ptep++)));
 358                 write_c0_entrylo1(pte_to_entrylo(pte_val(*ptep)));
 359 #endif
 360                 mtc0_tlbw_hazard();
 361                 if (idx < 0)
 362                         tlb_write_random();
 363                 else
 364                         tlb_write_indexed();
 365         }
 366         tlbw_use_hazard();
 367         htw_start();
 368         flush_micro_tlb_vm(vma);
 369         local_irq_restore(flags);
 370 }
 371
 372 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 373                      unsigned long entryhi, unsigned long pagemask)
 374 {
 375 #ifdef CONFIG_XPA
 376         panic("Broken for XPA kernels");
 377 #else
 378         unsigned long flags;
 379         unsigned long wired;
 380         unsigned long old_pagemask;
 381         unsigned long old_ctx;
 382
 383         local_irq_save(flags);
 384         /* Save old context and create impossible VPN2 value */
 385         old_ctx = read_c0_entryhi();
 386         htw_stop();
 387         old_pagemask = read_c0_pagemask();
 388         wired = num_wired_entries();
 389         write_c0_wired(wired + 1);
 390         write_c0_index(wired);
 391         tlbw_use_hazard();      /* What is the hazard here? */
 392         write_c0_pagemask(pagemask);
 393         write_c0_entryhi(entryhi);
 394         write_c0_entrylo0(entrylo0);
 395         write_c0_entrylo1(entrylo1);
 396         mtc0_tlbw_hazard();
 397         tlb_write_indexed();
 398         tlbw_use_hazard();
 399
 400         write_c0_entryhi(old_ctx);
 401         tlbw_use_hazard();      /* What is the hazard here? */
 402         htw_start();
 403         write_c0_pagemask(old_pagemask);
 404         local_flush_tlb_all();
 405         local_irq_restore(flags);
 406 #endif
 407 }
 408
 409 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 410
 411 int has_transparent_hugepage(void)
 412 {
 413         static unsigned int mask = -1;
 414
 415         if (mask == -1) {       /* first call comes during __init */
 416                 unsigned long flags;
 417
 418                 local_irq_save(flags);
 419                 write_c0_pagemask(PM_HUGE_MASK);
 420                 back_to_back_c0_hazard();
 421                 mask = read_c0_pagemask();
 422                 write_c0_pagemask(PM_DEFAULT_MASK);
 423                 local_irq_restore(flags);
 424         }
 425         return mask == PM_HUGE_MASK;
 426 }
 427
 428 #endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
 429
 430 /*
 431  * Used for loading TLB entries before trap_init() has started, when we
 432  * don't actually want to add a wired entry which remains throughout the
 433  * lifetime of the system
 434  */
 435
 436 int temp_tlb_entry;
 437
 438 __init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
 439                                unsigned long entryhi, unsigned long pagemask)
 440 {
 441         int ret = 0;
 442         unsigned long flags;
 443         unsigned long wired;
 444         unsigned long old_pagemask;
 445         unsigned long old_ctx;
 446
 447         local_irq_save(flags);
 448         /* Save old context and create impossible VPN2 value */
 449         htw_stop();
 450         old_ctx = read_c0_entryhi();
 451         old_pagemask = read_c0_pagemask();
 452         wired = num_wired_entries();
 453         if (--temp_tlb_entry < wired) {
 454                 printk(KERN_WARNING
 455                        "No TLB space left for add_temporary_entry\n");
 456                 ret = -ENOSPC;
 457                 goto out;
 458         }
 459
 460         write_c0_index(temp_tlb_entry);
 461         write_c0_pagemask(pagemask);
 462         write_c0_entryhi(entryhi);
 463         write_c0_entrylo0(entrylo0);
 464         write_c0_entrylo1(entrylo1);
 465         mtc0_tlbw_hazard();
 466         tlb_write_indexed();
 467         tlbw_use_hazard();
 468
 469         write_c0_entryhi(old_ctx);
 470         write_c0_pagemask(old_pagemask);
 471         htw_start();
 472 out:
 473         local_irq_restore(flags);
 474         return ret;
 475 }
 476
 477 static int ntlb;
 478 static int __init set_ntlb(char *str)
 479 {
 480         get_option(&str, &ntlb);
 481         return 1;
 482 }
 483
 484 __setup("ntlb=", set_ntlb);
 485
 486 /*
 487  * Configure TLB (for init or after a CPU has been powered off).
 488  */
 489 static void r4k_tlb_configure(void)
 490 {
 491         /*
 492          * You should never change this register:
 493          *   - On R4600 1.7 the tlbp never hits for pages smaller than
 494          *     the value in the c0_pagemask register.
 495          *   - The entire mm handling assumes the c0_pagemask register to
 496          *     be set to fixed-size pages.
 497          */
 498         write_c0_pagemask(PM_DEFAULT_MASK);
 499         back_to_back_c0_hazard();
 500         if (read_c0_pagemask() != PM_DEFAULT_MASK)
 501                 panic("MMU doesn't support PAGE_SIZE=0x%lx", PAGE_SIZE);
 502
 503         write_c0_wired(0);
 504         if (current_cpu_type() == CPU_R10000 ||
 505             current_cpu_type() == CPU_R12000 ||
 506             current_cpu_type() == CPU_R14000 ||
 507             current_cpu_type() == CPU_R16000)
 508                 write_c0_framemask(0);
 509
 510         if (cpu_has_rixi) {
 511                 /*
 512                  * Enable the no read, no exec bits, and enable large physical
 513                  * address.
 514                  */
 515 #ifdef CONFIG_64BIT
 516                 set_c0_pagegrain(PG_RIE | PG_XIE | PG_ELPA);
 517 #else
 518                 set_c0_pagegrain(PG_RIE | PG_XIE);
 519 #endif
 520         }
 521
 522         temp_tlb_entry = current_cpu_data.tlbsize - 1;
 523
 524         /* From this point on the ARC firmware is dead.  */
 525         local_flush_tlb_all();
 526
 527         /* Did I tell you that ARC SUCKS?  */
 528 }
 529
 530 void tlb_init(void)
 531 {
 532         r4k_tlb_configure();
 533
 534         if (ntlb) {
 535                 if (ntlb > 1 && ntlb <= current_cpu_data.tlbsize) {
 536                         int wired = current_cpu_data.tlbsize - ntlb;
 537                         write_c0_wired(wired);
 538                         write_c0_index(wired-1);
 539                         printk("Restricting TLB to %d entries\n", ntlb);
 540                 } else
 541                         printk("Ignoring invalid argument ntlb=%d\n", ntlb);
 542         }
 543
 544         build_tlb_refill_handler();
 545 }
 546
 547 static int r4k_tlb_pm_notifier(struct notifier_block *self, unsigned long cmd,
 548                                void *v)
 549 {
 550         switch (cmd) {
 551         case CPU_PM_ENTER_FAILED:
 552         case CPU_PM_EXIT:
 553                 r4k_tlb_configure();
 554                 break;
 555         }
 556
 557         return NOTIFY_OK;
 558 }
 559
 560 static struct notifier_block r4k_tlb_pm_notifier_block = {
 561         .notifier_call = r4k_tlb_pm_notifier,
 562 };
 563
 564 static int __init r4k_tlb_init_pm(void)
 565 {
 566         return cpu_pm_register_notifier(&r4k_tlb_pm_notifier_block);
 567 }
 568 arch_initcall(r4k_tlb_init_pm);