arch/mips/mm/tlb-sb1.c

   1 /*
   2  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
   3  * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org)
   4  * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  19  */
  20 #include <linux/init.h>
  21 #include <asm/mmu_context.h>
  22 #include <asm/bootinfo.h>
  23 #include <asm/cpu.h>
  24
  25 extern void build_tlb_refill_handler(void);
  26
  27 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
  28
  29 /* Dump the current entry* and pagemask registers */
  30 static inline void dump_cur_tlb_regs(void)
  31 {
  32         unsigned int entryhihi, entryhilo, entrylo0hi, entrylo0lo, entrylo1hi;
  33         unsigned int entrylo1lo, pagemask;
  34
  35         __asm__ __volatile__ (
  36                 ".set push             \n"
  37                 ".set noreorder        \n"
  38                 ".set mips64           \n"
  39                 ".set noat             \n"
  40                 "     tlbr             \n"
  41                 "     dmfc0  $1, $10   \n"
  42                 "     dsrl32 %0, $1, 0 \n"
  43                 "     sll    %1, $1, 0 \n"
  44                 "     dmfc0  $1, $2    \n"
  45                 "     dsrl32 %2, $1, 0 \n"
  46                 "     sll    %3, $1, 0 \n"
  47                 "     dmfc0  $1, $3    \n"
  48                 "     dsrl32 %4, $1, 0 \n"
  49                 "     sll    %5, $1, 0 \n"
  50                 "     mfc0   %6, $5    \n"
  51                 ".set pop              \n"
  52                 : "=r" (entryhihi), "=r" (entryhilo),
  53                   "=r" (entrylo0hi), "=r" (entrylo0lo),
  54                   "=r" (entrylo1hi), "=r" (entrylo1lo),
  55                   "=r" (pagemask));
  56
  57         printk("%08X%08X %08X%08X %08X%08X %08X",
  58                entryhihi, entryhilo,
  59                entrylo0hi, entrylo0lo,
  60                entrylo1hi, entrylo1lo,
  61                pagemask);
  62 }
  63
  64 void sb1_dump_tlb(void)
  65 {
  66         unsigned long old_ctx;
  67         unsigned long flags;
  68         int entry;
  69         local_irq_save(flags);
  70         old_ctx = read_c0_entryhi();
  71         printk("Current TLB registers state:\n"
  72                "      EntryHi       EntryLo0          EntryLo1     PageMask  Index\n"
  73                "--------------------------------------------------------------------\n");
  74         dump_cur_tlb_regs();
  75         printk(" %08X\n", read_c0_index());
  76         printk("\n\nFull TLB Dump:\n"
  77                "Idx      EntryHi       EntryLo0          EntryLo1     PageMask\n"
  78                "--------------------------------------------------------------\n");
  79         for (entry = 0; entry < current_cpu_data.tlbsize; entry++) {
  80                 write_c0_index(entry);
  81                 printk("\n%02i ", entry);
  82                 dump_cur_tlb_regs();
  83         }
  84         printk("\n");
  85         write_c0_entryhi(old_ctx);
  86         local_irq_restore(flags);
  87 }
  88
  89 void local_flush_tlb_all(void)
  90 {
  91         unsigned long flags;
  92         unsigned long old_ctx;
  93         int entry;
  94
  95         local_irq_save(flags);
  96         /* Save old context and create impossible VPN2 value */
  97         old_ctx = read_c0_entryhi() & ASID_MASK;
  98         write_c0_entrylo0(0);
  99         write_c0_entrylo1(0);
 100
 101         entry = read_c0_wired();
 102         while (entry < current_cpu_data.tlbsize) {
 103                 write_c0_entryhi(UNIQUE_ENTRYHI(entry));
 104                 write_c0_index(entry);
 105                 tlb_write_indexed();
 106                 entry++;
 107         }
 108         write_c0_entryhi(old_ctx);
 109         local_irq_restore(flags);
 110 }
 111
 112
 113 /*
 114  * Use a bogus region of memory (starting at 0) to sanitize the TLB's.
 115  * Use increments of the maximum page size (16MB), and check for duplicate
 116  * entries before doing a given write.  Then, when we're safe from collisions
 117  * with the firmware, go back and give all the entries invalid addresses with
 118  * the normal flush routine.  Wired entries will be killed as well!
 119  */
 120 static void __init sb1_sanitize_tlb(void)
 121 {
 122         int entry;
 123         long addr = 0;
 124
 125         long inc = 1<<24;  /* 16MB */
 126         /* Save old context and create impossible VPN2 value */
 127         write_c0_entrylo0(0);
 128         write_c0_entrylo1(0);
 129         for (entry = 0; entry < current_cpu_data.tlbsize; entry++) {
 130                 do {
 131                         addr += inc;
 132                         write_c0_entryhi(addr);
 133                         tlb_probe();
 134                 } while ((int)(read_c0_index()) >= 0);
 135                 write_c0_index(entry);
 136                 tlb_write_indexed();
 137         }
 138         /* Now that we know we're safe from collisions, we can safely flush
 139            the TLB with the "normal" routine. */
 140         local_flush_tlb_all();
 141 }
 142
 143 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 144         unsigned long end)
 145 {
 146         struct mm_struct *mm = vma->vm_mm;
 147         unsigned long flags;
 148         int cpu;
 149
 150         local_irq_save(flags);
 151         cpu = smp_processor_id();
 152         if (cpu_context(cpu, mm) != 0) {
 153                 int size;
 154                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 155                 size = (size + 1) >> 1;
 156                 if (size <= (current_cpu_data.tlbsize/2)) {
 157                         int oldpid = read_c0_entryhi() & ASID_MASK;
 158                         int newpid = cpu_asid(cpu, mm);
 159
 160                         start &= (PAGE_MASK << 1);
 161                         end += ((PAGE_SIZE << 1) - 1);
 162                         end &= (PAGE_MASK << 1);
 163                         while (start < end) {
 164                                 int idx;
 165
 166                                 write_c0_entryhi(start | newpid);
 167                                 start += (PAGE_SIZE << 1);
 168                                 tlb_probe();
 169                                 idx = read_c0_index();
 170                                 write_c0_entrylo0(0);
 171                                 write_c0_entrylo1(0);
 172                                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 173                                 if (idx < 0)
 174                                         continue;
 175                                 tlb_write_indexed();
 176                         }
 177                         write_c0_entryhi(oldpid);
 178                 } else {
 179                         drop_mmu_context(mm, cpu);
 180                 }
 181         }
 182         local_irq_restore(flags);
 183 }
 184
 185 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 186 {
 187         unsigned long flags;
 188         int size;
 189
 190         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 191         size = (size + 1) >> 1;
 192
 193         local_irq_save(flags);
 194         if (size <= (current_cpu_data.tlbsize/2)) {
 195                 int pid = read_c0_entryhi();
 196
 197                 start &= (PAGE_MASK << 1);
 198                 end += ((PAGE_SIZE << 1) - 1);
 199                 end &= (PAGE_MASK << 1);
 200
 201                 while (start < end) {
 202                         int idx;
 203
 204                         write_c0_entryhi(start);
 205                         start += (PAGE_SIZE << 1);
 206                         tlb_probe();
 207                         idx = read_c0_index();
 208                         write_c0_entrylo0(0);
 209                         write_c0_entrylo1(0);
 210                         write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 211                         if (idx < 0)
 212                                 continue;
 213                         tlb_write_indexed();
 214                 }
 215                 write_c0_entryhi(pid);
 216         } else {
 217                 local_flush_tlb_all();
 218         }
 219         local_irq_restore(flags);
 220 }
 221
 222 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 223 {
 224         unsigned long flags;
 225         int cpu = smp_processor_id();
 226
 227         local_irq_save(flags);
 228         if (cpu_context(cpu, vma->vm_mm) != 0) {
 229                 int oldpid, newpid, idx;
 230                 newpid = cpu_asid(cpu, vma->vm_mm);
 231                 page &= (PAGE_MASK << 1);
 232                 oldpid = read_c0_entryhi() & ASID_MASK;
 233                 write_c0_entryhi(page | newpid);
 234                 tlb_probe();
 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                 tlb_write_indexed();
 243         finish:
 244                 write_c0_entryhi(oldpid);
 245         }
 246         local_irq_restore(flags);
 247 }
 248
 249 /*
 250  * Remove one kernel space TLB entry.  This entry is assumed to be marked
 251  * global so we don't do the ASID thing.
 252  */
 253 void local_flush_tlb_one(unsigned long page)
 254 {
 255         unsigned long flags;
 256         int oldpid, idx;
 257
 258         page &= (PAGE_MASK << 1);
 259         oldpid = read_c0_entryhi() & ASID_MASK;
 260
 261         local_irq_save(flags);
 262         write_c0_entryhi(page);
 263         tlb_probe();
 264         idx = read_c0_index();
 265         if (idx >= 0) {
 266                 /* Make sure all entries differ. */
 267                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
 268                 write_c0_entrylo0(0);
 269                 write_c0_entrylo1(0);
 270                 tlb_write_indexed();
 271         }
 272
 273         write_c0_entryhi(oldpid);
 274         local_irq_restore(flags);
 275 }
 276
 277 /* All entries common to a mm share an asid.  To effectively flush
 278    these entries, we just bump the asid. */
 279 void local_flush_tlb_mm(struct mm_struct *mm)
 280 {
 281         int cpu;
 282
 283         preempt_disable();
 284
 285         cpu = smp_processor_id();
 286
 287         if (cpu_context(cpu, mm) != 0) {
 288                 drop_mmu_context(mm, cpu);
 289         }
 290
 291         preempt_enable();
 292 }
 293
 294 /* Stolen from mips32 routines */
 295
 296 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 297 {
 298         unsigned long flags;
 299         pgd_t *pgdp;
 300         pmd_t *pmdp;
 301         pte_t *ptep;
 302         int idx, pid;
 303
 304         /*
 305          * Handle debugger faulting in for debugee.
 306          */
 307         if (current->active_mm != vma->vm_mm)
 308                 return;
 309
 310         local_irq_save(flags);
 311
 312         pid = read_c0_entryhi() & ASID_MASK;
 313         address &= (PAGE_MASK << 1);
 314         write_c0_entryhi(address | (pid));
 315         pgdp = pgd_offset(vma->vm_mm, address);
 316         tlb_probe();
 317         pmdp = pmd_offset(pgdp, address);
 318         idx = read_c0_index();
 319         ptep = pte_offset_map(pmdp, address);
 320         write_c0_entrylo0(pte_val(*ptep++) >> 6);
 321         write_c0_entrylo1(pte_val(*ptep) >> 6);
 322         if (idx < 0) {
 323                 tlb_write_random();
 324         } else {
 325                 tlb_write_indexed();
 326         }
 327         local_irq_restore(flags);
 328 }
 329
 330 void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 331         unsigned long entryhi, unsigned long pagemask)
 332 {
 333         unsigned long flags;
 334         unsigned long wired;
 335         unsigned long old_pagemask;
 336         unsigned long old_ctx;
 337
 338         local_irq_save(flags);
 339         old_ctx = read_c0_entryhi() & 0xff;
 340         old_pagemask = read_c0_pagemask();
 341         wired = read_c0_wired();
 342         write_c0_wired(wired + 1);
 343         write_c0_index(wired);
 344
 345         write_c0_pagemask(pagemask);
 346         write_c0_entryhi(entryhi);
 347         write_c0_entrylo0(entrylo0);
 348         write_c0_entrylo1(entrylo1);
 349         tlb_write_indexed();
 350
 351         write_c0_entryhi(old_ctx);
 352         write_c0_pagemask(old_pagemask);
 353
 354         local_flush_tlb_all();
 355         local_irq_restore(flags);
 356 }
 357
 358 /*
 359  * This is called from loadmmu.c.  We have to set up all the
 360  * memory management function pointers, as well as initialize
 361  * the caches and tlbs
 362  */
 363 void tlb_init(void)
 364 {
 365         write_c0_pagemask(PM_DEFAULT_MASK);
 366         write_c0_wired(0);
 367
 368         /*
 369          * We don't know what state the firmware left the TLB's in, so this is
 370          * the ultra-conservative way to flush the TLB's and avoid machine
 371          * check exceptions due to duplicate TLB entries
 372          */
 373         sb1_sanitize_tlb();
 374
 375         build_tlb_refill_handler();
 376 }