kernel/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/mmu_context.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/tlb.h>
  25 #include <asm/tlbmisc.h>
  26
  27 extern void build_tlb_refill_handler(void);
  28
  29 /*
  30  * LOONGSON2/3 has a 4 entry itlb which is a subset of dtlb,
  31  * unfortunately, itlb is not totally transparent to software.
  32  */
  33 static inline void flush_itlb(void)
  34 {
  35         switch (current_cpu_type()) {
  36         case CPU_LOONGSON2:
  37         case CPU_LOONGSON3:
  38                 write_c0_diag(4);
  39                 break;
  40         default:
  41                 break;
  42         }
  43 }
  44
  45 static inline void flush_itlb_vm(struct vm_area_struct *vma)
  46 {
  47         if (vma->vm_flags & VM_EXEC)
  48                 flush_itlb();
  49 }
  50
  51 void local_flush_tlb_all(void)
  52 {
  53         unsigned long flags;
  54         unsigned long old_ctx;
  55         int entry, ftlbhighset;
  56
  57         local_irq_save(flags);
  58         /* Save old context and create impossible VPN2 value */
  59         old_ctx = read_c0_entryhi();
  60         htw_stop();
  61         write_c0_entrylo0(0);
  62         write_c0_entrylo1(0);
  63
  64         entry = read_c0_wired();
  65
  66         /* Blast 'em all away. */
  67         if (cpu_has_tlbinv) {
  68                 if (current_cpu_data.tlbsizevtlb) {
  69                         write_c0_index(0);
  70                         mtc0_tlbw_hazard();
  71                         tlbinvf();  /* invalidate VTLB */
  72                 }
  73                 ftlbhighset = current_cpu_data.tlbsizevtlb +
  74                         current_cpu_data.tlbsizeftlbsets;
  75                 for (entry = current_cpu_data.tlbsizevtlb;
  76                      entry < ftlbhighset;
  77                      entry++) {
  78                         write_c0_index(entry);
  79                         mtc0_tlbw_hazard();
  80                         tlbinvf();  /* invalidate one FTLB set */
  81                 }
  82         } else {
  83                 while (entry < current_cpu_data.tlbsize) {
  84                         /* Make sure all entries differ. */
  85                         write_c0_entryhi(UNIQUE_ENTRYHI(entry));
  86                         write_c0_index(entry);
  87                         mtc0_tlbw_hazard();
  88                         tlb_write_indexed();
  89                         entry++;
  90                 }
  91         }
  92         tlbw_use_hazard();
  93         write_c0_entryhi(old_ctx);
  94         htw_start();
  95         flush_itlb();
  96         local_irq_restore(flags);
  97 }
  98 EXPORT_SYMBOL(local_flush_tlb_all);
  99
 100 /* All entries common to a mm share an asid.  To effectively flush
 101    these entries, we just bump the asid. */
 102 void local_flush_tlb_mm(struct mm_struct *mm)
 103 {
 104         int cpu;
 105
 106         preempt_disable();
 107
 108         cpu = smp_processor_id();
 109
 110         if (cpu_context(cpu, mm) != 0) {
 111                 drop_mmu_context(mm, cpu);
 112         }
 113
 114         preempt_enable();
 115 }
 116
 117 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 118         unsigned long end)
 119 {
 120         struct mm_struct *mm = vma->vm_mm;
 121         int cpu = smp_processor_id();
 122
 123         if (cpu_context(cpu, mm) != 0) {
 124                 unsigned long size, flags;
 125
 126                 local_irq_save(flags);
 127                 start = round_down(start, PAGE_SIZE << 1);
 128                 end = round_up(end, PAGE_SIZE << 1);
 129                 size = (end - start) >> (PAGE_SHIFT + 1);
 130                 if (size <= (current_cpu_data.tlbsizeftlbsets ?
 131                              current_cpu_data.tlbsize / 8 :
 132                              current_cpu_data.tlbsize / 2)) {
 133                         int oldpid = read_c0_entryhi();
 134                         int newpid = cpu_asid(cpu, mm);
 135
 136                         htw_stop();
 137                         while (start < end) {
 138                                 int idx;
 139
 140                                 write_c0_entryhi(start | newpid);
 141                                 start += (PAGE_SIZE << 1);
 142                                 mtc0_tlbw_hazard();
 143                                 tlb_probe();
 144                                 tlb_probe_hazard();
 145                                 idx = read_c0_index();
 146                                 write_c0_entrylo0(0);
 147                                 write_c0_entrylo1(0);
 148                                 if (idx < 0)
 149                                         continue;
 150                                 /* Make sure all entries differ. */
 151                                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 152                                 mtc0_tlbw_hazard();
 153                                 tlb_write_indexed();
 154                         }
 155                         tlbw_use_hazard();
 156                         write_c0_entryhi(oldpid);
 157                         htw_start();
 158                 } else {
 159                         drop_mmu_context(mm, cpu);
 160                 }
 161                 flush_itlb();
 162                 local_irq_restore(flags);
 163         }
 164 }
 165
 166 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 167 {
 168         unsigned long size, flags;
 169
 170         local_irq_save(flags);
 171         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 172         size = (size + 1) >> 1;
 173         if (size <= (current_cpu_data.tlbsizeftlbsets ?
 174                      current_cpu_data.tlbsize / 8 :
 175                      current_cpu_data.tlbsize / 2)) {
 176                 int pid = read_c0_entryhi();
 177
 178                 start &= (PAGE_MASK << 1);
 179                 end += ((PAGE_SIZE << 1) - 1);
 180                 end &= (PAGE_MASK << 1);
 181                 htw_stop();
 182
 183                 while (start < end) {
 184                         int idx;
 185
 186                         write_c0_entryhi(start);
 187                         start += (PAGE_SIZE << 1);
 188                         mtc0_tlbw_hazard();
 189                         tlb_probe();
 190                         tlb_probe_hazard();
 191                         idx = read_c0_index();
 192                         write_c0_entrylo0(0);
 193                         write_c0_entrylo1(0);
 194                         if (idx < 0)
 195                                 continue;
 196                         /* Make sure all entries differ. */
 197                         write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 198                         mtc0_tlbw_hazard();
 199                         tlb_write_indexed();
 200                 }
 201                 tlbw_use_hazard();
 202                 write_c0_entryhi(pid);
 203                 htw_start();
 204         } else {
 205                 local_flush_tlb_all();
 206         }
 207         flush_itlb();
 208         local_irq_restore(flags);
 209 }
 210
 211 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 212 {
 213         int cpu = smp_processor_id();
 214
 215         if (cpu_context(cpu, vma->vm_mm) != 0) {
 216                 unsigned long flags;
 217                 int oldpid, newpid, idx;
 218
 219                 newpid = cpu_asid(cpu, vma->vm_mm);
 220                 page &= (PAGE_MASK << 1);
 221                 local_irq_save(flags);
 222                 oldpid = read_c0_entryhi();
 223                 htw_stop();
 224                 write_c0_entryhi(page | newpid);
 225                 mtc0_tlbw_hazard();
 226                 tlb_probe();
 227                 tlb_probe_hazard();
 228                 idx = read_c0_index();
 229                 write_c0_entrylo0(0);
 230                 write_c0_entrylo1(0);
 231                 if (idx < 0)
 232                         goto finish;
 233                 /* Make sure all entries differ. */
 234                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 235                 mtc0_tlbw_hazard();
 236                 tlb_write_indexed();
 237                 tlbw_use_hazard();
 238
 239         finish:
 240                 write_c0_entryhi(oldpid);
 241                 htw_start();
 242                 flush_itlb_vm(vma);
 243                 local_irq_restore(flags);
 244         }
 245 }
 246
 247 /*
 248  * This one is only used for pages with the global bit set so we don't care
 249  * much about the ASID.
 250  */
 251 void local_flush_tlb_one(unsigned long page)
 252 {
 253         unsigned long flags;
 254         int oldpid, idx;
 255
 256         local_irq_save(flags);
 257         oldpid = read_c0_entryhi();
 258         htw_stop();
 259         page &= (PAGE_MASK << 1);
 260         write_c0_entryhi(page);
 261         mtc0_tlbw_hazard();
 262         tlb_probe();
 263         tlb_probe_hazard();
 264         idx = read_c0_index();
 265         write_c0_entrylo0(0);
 266         write_c0_entrylo1(0);
 267         if (idx >= 0) {
 268                 /* Make sure all entries differ. */
 269                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 270                 mtc0_tlbw_hazard();
 271                 tlb_write_indexed();
 272                 tlbw_use_hazard();
 273         }
 274         write_c0_entryhi(oldpid);
 275         htw_start();
 276         flush_itlb();
 277         local_irq_restore(flags);
 278 }
 279
 280 /*
 281  * We will need multiple versions of update_mmu_cache(), one that just
 282  * updates the TLB with the new pte(s), and another which also checks
 283  * for the R4k "end of page" hardware bug and does the needy.
 284  */
 285 void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 286 {
 287         unsigned long flags;
 288         pgd_t *pgdp;
 289         pud_t *pudp;
 290         pmd_t *pmdp;
 291         pte_t *ptep;
 292         int idx, pid;
 293
 294         /*
 295          * Handle debugger faulting in for debugee.
 296          */
 297         if (current->active_mm != vma->vm_mm)
 298                 return;
 299
 300         local_irq_save(flags);
 301
 302         htw_stop();
 303         pid = read_c0_entryhi() & ASID_MASK;
 304         address &= (PAGE_MASK << 1);
 305         write_c0_entryhi(address | pid);
 306         pgdp = pgd_offset(vma->vm_mm, address);
 307         mtc0_tlbw_hazard();
 308         tlb_probe();
 309         tlb_probe_hazard();
 310         pudp = pud_offset(pgdp, address);
 311         pmdp = pmd_offset(pudp, address);
 312         idx = read_c0_index();
 313 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 314         /* this could be a huge page  */
 315         if (pmd_huge(*pmdp)) {
 316                 unsigned long lo;
 317                 write_c0_pagemask(PM_HUGE_MASK);
 318                 ptep = (pte_t *)pmdp;
 319                 lo = pte_to_entrylo(pte_val(*ptep));
 320                 write_c0_entrylo0(lo);
 321                 write_c0_entrylo1(lo + (HPAGE_SIZE >> 7));
 322
 323                 mtc0_tlbw_hazard();
 324                 if (idx < 0)
 325                         tlb_write_random();
 326                 else
 327                         tlb_write_indexed();
 328                 tlbw_use_hazard();
 329                 write_c0_pagemask(PM_DEFAULT_MASK);
 330         } else
 331 #endif
 332         {
 333                 ptep = pte_offset_map(pmdp, address);
 334
 335 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 336 #ifdef CONFIG_XPA
 337                 write_c0_entrylo0(pte_to_entrylo(ptep->pte_high));
 338                 writex_c0_entrylo0(ptep->pte_low & _PFNX_MASK);
 339                 ptep++;
 340                 write_c0_entrylo1(pte_to_entrylo(ptep->pte_high));
 341                 writex_c0_entrylo1(ptep->pte_low & _PFNX_MASK);
 342 #else
 343                 write_c0_entrylo0(ptep->pte_high);
 344                 ptep++;
 345                 write_c0_entrylo1(ptep->pte_high);
 346 #endif
 347 #else
 348                 write_c0_entrylo0(pte_to_entrylo(pte_val(*ptep++)));
 349                 write_c0_entrylo1(pte_to_entrylo(pte_val(*ptep)));
 350 #endif
 351                 mtc0_tlbw_hazard();
 352                 if (idx < 0)
 353                         tlb_write_random();
 354                 else
 355                         tlb_write_indexed();
 356         }
 357         tlbw_use_hazard();
 358         htw_start();
 359         flush_itlb_vm(vma);
 360         local_irq_restore(flags);
 361 }
 362
 363 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 364                      unsigned long entryhi, unsigned long pagemask)
 365 {
 366 #ifdef CONFIG_XPA
 367         panic("Broken for XPA kernels");
 368 #else
 369         unsigned long flags;
 370         unsigned long wired;
 371         unsigned long old_pagemask;
 372         unsigned long old_ctx;
 373
 374         local_irq_save(flags);
 375         /* Save old context and create impossible VPN2 value */
 376         old_ctx = read_c0_entryhi();
 377         htw_stop();
 378         old_pagemask = read_c0_pagemask();
 379         wired = read_c0_wired();
 380         write_c0_wired(wired + 1);
 381         write_c0_index(wired);
 382         tlbw_use_hazard();      /* What is the hazard here? */
 383         write_c0_pagemask(pagemask);
 384         write_c0_entryhi(entryhi);
 385         write_c0_entrylo0(entrylo0);
 386         write_c0_entrylo1(entrylo1);
 387         mtc0_tlbw_hazard();
 388         tlb_write_indexed();
 389         tlbw_use_hazard();
 390
 391         write_c0_entryhi(old_ctx);
 392         tlbw_use_hazard();      /* What is the hazard here? */
 393         htw_start();
 394         write_c0_pagemask(old_pagemask);
 395         local_flush_tlb_all();
 396         local_irq_restore(flags);
 397 #endif
 398 }
 399
 400 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 401
 402 int __init has_transparent_hugepage(void)
 403 {
 404         unsigned int mask;
 405         unsigned long flags;
 406
 407         local_irq_save(flags);
 408         write_c0_pagemask(PM_HUGE_MASK);
 409         back_to_back_c0_hazard();
 410         mask = read_c0_pagemask();
 411         write_c0_pagemask(PM_DEFAULT_MASK);
 412
 413         local_irq_restore(flags);
 414
 415         return mask == PM_HUGE_MASK;
 416 }
 417
 418 #endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
 419
 420 /*
 421  * Used for loading TLB entries before trap_init() has started, when we
 422  * don't actually want to add a wired entry which remains throughout the
 423  * lifetime of the system
 424  */
 425
 426 int temp_tlb_entry __cpuinitdata;
 427
 428 __init int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
 429                                unsigned long entryhi, unsigned long pagemask)
 430 {
 431         int ret = 0;
 432         unsigned long flags;
 433         unsigned long wired;
 434         unsigned long old_pagemask;
 435         unsigned long old_ctx;
 436
 437         local_irq_save(flags);
 438         /* Save old context and create impossible VPN2 value */
 439         htw_stop();
 440         old_ctx = read_c0_entryhi();
 441         old_pagemask = read_c0_pagemask();
 442         wired = read_c0_wired();
 443         if (--temp_tlb_entry < wired) {
 444                 printk(KERN_WARNING
 445                        "No TLB space left for add_temporary_entry\n");
 446                 ret = -ENOSPC;
 447                 goto out;
 448         }
 449
 450         write_c0_index(temp_tlb_entry);
 451         write_c0_pagemask(pagemask);
 452         write_c0_entryhi(entryhi);
 453         write_c0_entrylo0(entrylo0);
 454         write_c0_entrylo1(entrylo1);
 455         mtc0_tlbw_hazard();
 456         tlb_write_indexed();
 457         tlbw_use_hazard();
 458
 459         write_c0_entryhi(old_ctx);
 460         write_c0_pagemask(old_pagemask);
 461         htw_start();
 462 out:
 463         local_irq_restore(flags);
 464         return ret;
 465 }
 466
 467 static int ntlb;
 468 static int __init set_ntlb(char *str)
 469 {
 470         get_option(&str, &ntlb);
 471         return 1;
 472 }
 473
 474 __setup("ntlb=", set_ntlb);
 475
 476 /*
 477  * Configure TLB (for init or after a CPU has been powered off).
 478  */
 479 static void r4k_tlb_configure(void)
 480 {
 481         /*
 482          * You should never change this register:
 483          *   - On R4600 1.7 the tlbp never hits for pages smaller than
 484          *     the value in the c0_pagemask register.
 485          *   - The entire mm handling assumes the c0_pagemask register to
 486          *     be set to fixed-size pages.
 487          */
 488         write_c0_pagemask(PM_DEFAULT_MASK);
 489         write_c0_wired(0);
 490         if (current_cpu_type() == CPU_R10000 ||
 491             current_cpu_type() == CPU_R12000 ||
 492             current_cpu_type() == CPU_R14000 ||
 493             current_cpu_type() == CPU_R16000)
 494                 write_c0_framemask(0);
 495
 496         if (cpu_has_rixi) {
 497                 /*
 498                  * Enable the no read, no exec bits, and enable large physical
 499                  * address.
 500                  */
 501 #ifdef CONFIG_64BIT
 502                 set_c0_pagegrain(PG_RIE | PG_XIE | PG_ELPA);
 503 #else
 504                 set_c0_pagegrain(PG_RIE | PG_XIE);
 505 #endif
 506         }
 507
 508         temp_tlb_entry = current_cpu_data.tlbsize - 1;
 509
 510         /* From this point on the ARC firmware is dead.  */
 511         local_flush_tlb_all();
 512
 513         /* Did I tell you that ARC SUCKS?  */
 514 }
 515
 516 void tlb_init(void)
 517 {
 518         r4k_tlb_configure();
 519
 520         if (ntlb) {
 521                 if (ntlb > 1 && ntlb <= current_cpu_data.tlbsize) {
 522                         int wired = current_cpu_data.tlbsize - ntlb;
 523                         write_c0_wired(wired);
 524                         write_c0_index(wired-1);
 525                         printk("Restricting TLB to %d entries\n", ntlb);
 526                 } else
 527                         printk("Ignoring invalid argument ntlb=%d\n", ntlb);
 528         }
 529
 530         build_tlb_refill_handler();
 531 }
 532
 533 static int r4k_tlb_pm_notifier(struct notifier_block *self, unsigned long cmd,
 534                                void *v)
 535 {
 536         switch (cmd) {
 537         case CPU_PM_ENTER_FAILED:
 538         case CPU_PM_EXIT:
 539                 r4k_tlb_configure();
 540                 break;
 541         }
 542
 543         return NOTIFY_OK;
 544 }
 545
 546 static struct notifier_block r4k_tlb_pm_notifier_block = {
 547         .notifier_call = r4k_tlb_pm_notifier,
 548 };
 549
 550 static int __init r4k_tlb_init_pm(void)
 551 {
 552         return cpu_pm_register_notifier(&r4k_tlb_pm_notifier_block);
 553 }
 554 arch_initcall(r4k_tlb_init_pm);