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/module.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 = read_c0_wired();
  69
  70         /* Blast 'em all away. */
  71         if (cpu_has_tlbinv) {
  72                 if (current_cpu_data.tlbsizevtlb) {
  73                         write_c0_index(0);
  74                         mtc0_tlbw_hazard();
  75                         tlbinvf();  /* invalidate VTLB */
  76                 }
  77                 ftlbhighset = current_cpu_data.tlbsizevtlb +
  78                         current_cpu_data.tlbsizeftlbsets;
  79                 for (entry = current_cpu_data.tlbsizevtlb;
  80                      entry < ftlbhighset;
  81                      entry++) {
  82                         write_c0_index(entry);
  83                         mtc0_tlbw_hazard();
  84                         tlbinvf();  /* invalidate one FTLB set */
  85                 }
  86         } else {
  87                 while (entry < current_cpu_data.tlbsize) {
  88                         /* Make sure all entries differ. */
  89                         write_c0_entryhi(UNIQUE_ENTRYHI(entry));
  90                         write_c0_index(entry);
  91                         mtc0_tlbw_hazard();
  92                         tlb_write_indexed();
  93                         entry++;
  94                 }
  95         }
  96         tlbw_use_hazard();
  97         write_c0_entryhi(old_ctx);
  98         htw_start();
  99         flush_micro_tlb();
 100         local_irq_restore(flags);
 101 }
 102 EXPORT_SYMBOL(local_flush_tlb_all);
 103
 104 /* All entries common to a mm share an asid.  To effectively flush
 105    these entries, we just bump the asid. */
 106 void local_flush_tlb_mm(struct mm_struct *mm)
 107 {
 108         int cpu;
 109
 110         preempt_disable();
 111
 112         cpu = smp_processor_id();
 113
 114         if (cpu_context(cpu, mm) != 0) {
 115                 drop_mmu_context(mm, cpu);
 116         }
 117
 118         preempt_enable();
 119 }
 120
 121 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 122         unsigned long end)
 123 {
 124         struct mm_struct *mm = vma->vm_mm;
 125         int cpu = smp_processor_id();
 126
 127         if (cpu_context(cpu, mm) != 0) {
 128                 unsigned long size, flags;
 129
 130                 local_irq_save(flags);
 131                 start = round_down(start, PAGE_SIZE << 1);
 132                 end = round_up(end, PAGE_SIZE << 1);
 133                 size = (end - start) >> (PAGE_SHIFT + 1);
 134                 if (size <= (current_cpu_data.tlbsizeftlbsets ?
 135                              current_cpu_data.tlbsize / 8 :
 136                              current_cpu_data.tlbsize / 2)) {
 137                         int oldpid = read_c0_entryhi();
 138                         int newpid = cpu_asid(cpu, mm);
 139
 140                         htw_stop();
 141                         while (start < end) {
 142                                 int idx;
 143
 144                                 write_c0_entryhi(start | newpid);
 145                                 start += (PAGE_SIZE << 1);
 146                                 mtc0_tlbw_hazard();
 147                                 tlb_probe();
 148                                 tlb_probe_hazard();
 149                                 idx = read_c0_index();
 150                                 write_c0_entrylo0(0);
 151                                 write_c0_entrylo1(0);
 152                                 if (idx < 0)
 153                                         continue;
 154                                 /* Make sure all entries differ. */
 155                                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 156                                 mtc0_tlbw_hazard();
 157                                 tlb_write_indexed();
 158                         }
 159                         tlbw_use_hazard();
 160                         write_c0_entryhi(oldpid);
 161                         htw_start();
 162                 } else {
 163                         drop_mmu_context(mm, cpu);
 164                 }
 165                 flush_micro_tlb();
 166                 local_irq_restore(flags);
 167         }
 168 }
 169
 170 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 171 {
 172         unsigned long size, flags;
 173
 174         local_irq_save(flags);
 175         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 176         size = (size + 1) >> 1;
 177         if (size <= (current_cpu_data.tlbsizeftlbsets ?
 178                      current_cpu_data.tlbsize / 8 :
 179                      current_cpu_data.tlbsize / 2)) {
 180                 int pid = read_c0_entryhi();
 181
 182                 start &= (PAGE_MASK << 1);
 183                 end += ((PAGE_SIZE << 1) - 1);
 184                 end &= (PAGE_MASK << 1);
 185                 htw_stop();
 186
 187                 while (start < end) {
 188                         int idx;
 189
 190                         write_c0_entryhi(start);
 191                         start += (PAGE_SIZE << 1);
 192                         mtc0_tlbw_hazard();
 193                         tlb_probe();
 194                         tlb_probe_hazard();
 195                         idx = read_c0_index();
 196                         write_c0_entrylo0(0);
 197                         write_c0_entrylo1(0);
 198                         if (idx < 0)
 199                                 continue;
 200                         /* Make sure all entries differ. */
 201                         write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 202                         mtc0_tlbw_hazard();
 203                         tlb_write_indexed();
 204                 }
 205                 tlbw_use_hazard();
 206                 write_c0_entryhi(pid);
 207                 htw_start();
 208         } else {
 209                 local_flush_tlb_all();
 210         }
 211         flush_micro_tlb();
 212         local_irq_restore(flags);
 213 }
 214
 215 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 216 {
 217         int cpu = smp_processor_id();
 218
 219         if (cpu_context(cpu, vma->vm_mm) != 0) {
 220                 unsigned long flags;
 221                 int oldpid, newpid, idx;
 222
 223                 newpid = cpu_asid(cpu, vma->vm_mm);
 224                 page &= (PAGE_MASK << 1);
 225                 local_irq_save(flags);
 226                 oldpid = read_c0_entryhi();
 227                 htw_stop();
 228                 write_c0_entryhi(page | newpid);
 229                 mtc0_tlbw_hazard();
 230                 tlb_probe();
 231                 tlb_probe_hazard();
 232                 idx = read_c0_index();
 233                 write_c0_entrylo0(0);
 234                 write_c0_entrylo1(0);
 235                 if (idx < 0)
 236                         goto finish;
 237                 /* Make sure all entries differ. */
 238                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 239                 mtc0_tlbw_hazard();
 240                 tlb_write_indexed();
 241                 tlbw_use_hazard();
 242
 243         finish:
 244                 write_c0_entryhi(oldpid);
 245                 htw_start();
 246                 flush_micro_tlb_vm(vma);
 247                 local_irq_restore(flags);
 248         }
 249 }
 250
 251 /*
 252  * This one is only used for pages with the global bit set so we don't care
 253  * much about the ASID.
 254  */
 255 void local_flush_tlb_one(unsigned long page)
 256 {
 257         unsigned long flags;
 258         int oldpid, idx;
 259
 260         local_irq_save(flags);
 261         oldpid = read_c0_entryhi();
 262         htw_stop();
 263         page &= (PAGE_MASK << 1);
 264         write_c0_entryhi(page);
 265         mtc0_tlbw_hazard();
 266         tlb_probe();
 267         tlb_probe_hazard();
 268         idx = read_c0_index();
 269         write_c0_entrylo0(0);
 270         write_c0_entrylo1(0);
 271         if (idx >= 0) {
 272                 /* Make sure all entries differ. */
 273                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 274                 mtc0_tlbw_hazard();
 275                 tlb_write_indexed();
 276                 tlbw_use_hazard();
 277         }
 278         write_c0_entryhi(oldpid);
 279         htw_start();
 280         flush_micro_tlb();
 281         local_irq_restore(flags);
 282 }
 283
 284 /*
 285  * We will need multiple versions of update_mmu_cache(), one that just
 286  * updates the TLB with the new pte(s), and another which also checks
 287  * for the R4k "end of page" hardware bug and does the needy.
 288  */
 289 void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 290 {
 291         unsigned long flags;
 292         pgd_t *pgdp;
 293         pud_t *pudp;
 294         pmd_t *pmdp;
 295         pte_t *ptep;
 296         int idx, pid;
 297
 298         /*
 299          * Handle debugger faulting in for debugee.
 300          */
 301         if (current->active_mm != vma->vm_mm)
 302                 return;
 303
 304         local_irq_save(flags);
 305
 306         htw_stop();
 307         pid = read_c0_entryhi() & cpu_asid_mask(&current_cpu_data);
 308         address &= (PAGE_MASK << 1);
 309         write_c0_entryhi(address | pid);
 310         pgdp = pgd_offset(vma->vm_mm, address);
 311         mtc0_tlbw_hazard();
 312         tlb_probe();
 313         tlb_probe_hazard();
 314         pudp = pud_offset(pgdp, address);
 315         pmdp = pmd_offset(pudp, address);
 316         idx = read_c0_index();
 317 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 318         /* this could be a huge page  */
 319         if (pmd_huge(*pmdp)) {
 320                 unsigned long lo;
 321                 write_c0_pagemask(PM_HUGE_MASK);
 322                 ptep = (pte_t *)pmdp;
 323                 lo = pte_to_entrylo(pte_val(*ptep));
 324                 write_c0_entrylo0(lo);
 325                 write_c0_entrylo1(lo + (HPAGE_SIZE >> 7));
 326
 327                 mtc0_tlbw_hazard();
 328                 if (idx < 0)
 329                         tlb_write_random();
 330                 else
 331                         tlb_write_indexed();
 332                 tlbw_use_hazard();
 333                 write_c0_pagemask(PM_DEFAULT_MASK);
 334         } else
 335 #endif
 336         {
 337                 ptep = pte_offset_map(pmdp, address);
 338
 339 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 340 #ifdef CONFIG_XPA
 341                 write_c0_entrylo0(pte_to_entrylo(ptep->pte_high));
 342                 if (cpu_has_xpa)
 343                         writex_c0_entrylo0(ptep->pte_low & _PFNX_MASK);
 344                 ptep++;
 345                 write_c0_entrylo1(pte_to_entrylo(ptep->pte_high));
 346                 if (cpu_has_xpa)
 347                         writex_c0_entrylo1(ptep->pte_low & _PFNX_MASK);
 348 #else
 349                 write_c0_entrylo0(ptep->pte_high);
 350                 ptep++;
 351                 write_c0_entrylo1(ptep->pte_high);
 352 #endif
 353 #else
 354                 write_c0_entrylo0(pte_to_entrylo(pte_val(*ptep++)));
 355                 write_c0_entrylo1(pte_to_entrylo(pte_val(*ptep)));
 356 #endif
 357                 mtc0_tlbw_hazard();
 358                 if (idx < 0)
 359                         tlb_write_random();
 360                 else
 361                         tlb_write_indexed();
 362         }
 363         tlbw_use_hazard();
 364         htw_start();
 365         flush_micro_tlb_vm(vma);
 366         local_irq_restore(flags);
 367 }
 368
 369 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 370                      unsigned long entryhi, unsigned long pagemask)
 371 {
 372 #ifdef CONFIG_XPA
 373         panic("Broken for XPA kernels");
 374 #else
 375         unsigned long flags;
 376         unsigned long wired;
 377         unsigned long old_pagemask;
 378         unsigned long old_ctx;
 379
 380         local_irq_save(flags);
 381         /* Save old context and create impossible VPN2 value */
 382         old_ctx = read_c0_entryhi();
 383         htw_stop();
 384         old_pagemask = read_c0_pagemask();
 385         wired = read_c0_wired();
 386         write_c0_wired(wired + 1);
 387         write_c0_index(wired);
 388         tlbw_use_hazard();      /* What is the hazard here? */
 389         write_c0_pagemask(pagemask);
 390         write_c0_entryhi(entryhi);
 391         write_c0_entrylo0(entrylo0);
 392         write_c0_entrylo1(entrylo1);
 393         mtc0_tlbw_hazard();
 394         tlb_write_indexed();
 395         tlbw_use_hazard();
 396
 397         write_c0_entryhi(old_ctx);
 398         tlbw_use_hazard();      /* What is the hazard here? */
 399         htw_start();
 400         write_c0_pagemask(old_pagemask);
 401         local_flush_tlb_all();
 402         local_irq_restore(flags);
 403 #endif
 404 }
 405
 406 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 407
 408 int has_transparent_hugepage(void)
 409 {
 410         static unsigned int mask = -1;
 411
 412         if (mask == -1) {       /* first call comes during __init */
 413                 unsigned long flags;
 414
 415                 local_irq_save(flags);
 416                 write_c0_pagemask(PM_HUGE_MASK);
 417                 back_to_back_c0_hazard();
 418                 mask = read_c0_pagemask();
 419                 write_c0_pagemask(PM_DEFAULT_MASK);
 420                 local_irq_restore(flags);
 421         }
 422         return mask == PM_HUGE_MASK;
 423 }
 424
 425 #endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
 426
 427 /*
 428  * Used for loading TLB entries before trap_init() has started, when we
 429  * don't actually want to add a wired entry which remains throughout the
 430  * lifetime of the system
 431  */
 432
 433 int temp_tlb_entry;
 434
 435 __init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
 436                                unsigned long entryhi, unsigned long pagemask)
 437 {
 438         int ret = 0;
 439         unsigned long flags;
 440         unsigned long wired;
 441         unsigned long old_pagemask;
 442         unsigned long old_ctx;
 443
 444         local_irq_save(flags);
 445         /* Save old context and create impossible VPN2 value */
 446         htw_stop();
 447         old_ctx = read_c0_entryhi();
 448         old_pagemask = read_c0_pagemask();
 449         wired = read_c0_wired();
 450         if (--temp_tlb_entry < wired) {
 451                 printk(KERN_WARNING
 452                        "No TLB space left for add_temporary_entry\n");
 453                 ret = -ENOSPC;
 454                 goto out;
 455         }
 456
 457         write_c0_index(temp_tlb_entry);
 458         write_c0_pagemask(pagemask);
 459         write_c0_entryhi(entryhi);
 460         write_c0_entrylo0(entrylo0);
 461         write_c0_entrylo1(entrylo1);
 462         mtc0_tlbw_hazard();
 463         tlb_write_indexed();
 464         tlbw_use_hazard();
 465
 466         write_c0_entryhi(old_ctx);
 467         write_c0_pagemask(old_pagemask);
 468         htw_start();
 469 out:
 470         local_irq_restore(flags);
 471         return ret;
 472 }
 473
 474 static int ntlb;
 475 static int __init set_ntlb(char *str)
 476 {
 477         get_option(&str, &ntlb);
 478         return 1;
 479 }
 480
 481 __setup("ntlb=", set_ntlb);
 482
 483 /*
 484  * Configure TLB (for init or after a CPU has been powered off).
 485  */
 486 static void r4k_tlb_configure(void)
 487 {
 488         /*
 489          * You should never change this register:
 490          *   - On R4600 1.7 the tlbp never hits for pages smaller than
 491          *     the value in the c0_pagemask register.
 492          *   - The entire mm handling assumes the c0_pagemask register to
 493          *     be set to fixed-size pages.
 494          */
 495         write_c0_pagemask(PM_DEFAULT_MASK);
 496         back_to_back_c0_hazard();
 497         if (read_c0_pagemask() != PM_DEFAULT_MASK)
 498                 panic("MMU doesn't support PAGE_SIZE=0x%lx", PAGE_SIZE);
 499
 500         write_c0_wired(0);
 501         if (current_cpu_type() == CPU_R10000 ||
 502             current_cpu_type() == CPU_R12000 ||
 503             current_cpu_type() == CPU_R14000 ||
 504             current_cpu_type() == CPU_R16000)
 505                 write_c0_framemask(0);
 506
 507         if (cpu_has_rixi) {
 508                 /*
 509                  * Enable the no read, no exec bits, and enable large physical
 510                  * address.
 511                  */
 512 #ifdef CONFIG_64BIT
 513                 set_c0_pagegrain(PG_RIE | PG_XIE | PG_ELPA);
 514 #else
 515                 set_c0_pagegrain(PG_RIE | PG_XIE);
 516 #endif
 517         }
 518
 519         temp_tlb_entry = current_cpu_data.tlbsize - 1;
 520
 521         /* From this point on the ARC firmware is dead.  */
 522         local_flush_tlb_all();
 523
 524         /* Did I tell you that ARC SUCKS?  */
 525 }
 526
 527 void tlb_init(void)
 528 {
 529         r4k_tlb_configure();
 530
 531         if (ntlb) {
 532                 if (ntlb > 1 && ntlb <= current_cpu_data.tlbsize) {
 533                         int wired = current_cpu_data.tlbsize - ntlb;
 534                         write_c0_wired(wired);
 535                         write_c0_index(wired-1);
 536                         printk("Restricting TLB to %d entries\n", ntlb);
 537                 } else
 538                         printk("Ignoring invalid argument ntlb=%d\n", ntlb);
 539         }
 540
 541         build_tlb_refill_handler();
 542 }
 543
 544 static int r4k_tlb_pm_notifier(struct notifier_block *self, unsigned long cmd,
 545                                void *v)
 546 {
 547         switch (cmd) {
 548         case CPU_PM_ENTER_FAILED:
 549         case CPU_PM_EXIT:
 550                 r4k_tlb_configure();
 551                 break;
 552         }
 553
 554         return NOTIFY_OK;
 555 }
 556
 557 static struct notifier_block r4k_tlb_pm_notifier_block = {
 558         .notifier_call = r4k_tlb_pm_notifier,
 559 };
 560
 561 static int __init r4k_tlb_init_pm(void)
 562 {
 563         return cpu_pm_register_notifier(&r4k_tlb_pm_notifier_block);
 564 }
 565 arch_initcall(r4k_tlb_init_pm);