arch/mips/mm/tlb-r3k.c

   1 /*
   2  * r2300.c: R2000 and R3000 specific mmu/cache code.
   3  *
   4  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
   5  *
   6  * with a lot of changes to make this thing work for R3000s
   7  * Tx39XX R4k style caches added. HK
   8  * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
   9  * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
  10  * Copyright (C) 2002  Ralf Baechle
  11  * Copyright (C) 2002  Maciej W. Rozycki
  12  */
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/sched.h>
  16 #include <linux/smp.h>
  17 #include <linux/mm.h>
  18
  19 #include <asm/page.h>
  20 #include <asm/pgtable.h>
  21 #include <asm/mmu_context.h>
  22 #include <asm/system.h>
  23 #include <asm/isadep.h>
  24 #include <asm/io.h>
  25 #include <asm/bootinfo.h>
  26 #include <asm/cpu.h>
  27
  28 #undef DEBUG_TLB
  29
  30 extern void build_tlb_refill_handler(void);
  31
  32 /* CP0 hazard avoidance. */
  33 #define BARRIER                         \
  34         __asm__ __volatile__(           \
  35                 ".set   push\n\t"       \
  36                 ".set   noreorder\n\t"  \
  37                 "nop\n\t"               \
  38                 ".set   pop\n\t")
  39
  40 int r3k_have_wired_reg;         /* should be in cpu_data? */
  41
  42 /* TLB operations. */
  43 void local_flush_tlb_all(void)
  44 {
  45         unsigned long flags;
  46         unsigned long old_ctx;
  47         int entry;
  48
  49 #ifdef DEBUG_TLB
  50         printk("[tlball]");
  51 #endif
  52
  53         local_irq_save(flags);
  54         old_ctx = read_c0_entryhi() & ASID_MASK;
  55         write_c0_entrylo0(0);
  56         entry = r3k_have_wired_reg ? read_c0_wired() : 8;
  57         for (; entry < current_cpu_data.tlbsize; entry++) {
  58                 write_c0_index(entry << 8);
  59                 write_c0_entryhi((entry | 0x80000) << 12);
  60                 BARRIER;
  61                 tlb_write_indexed();
  62         }
  63         write_c0_entryhi(old_ctx);
  64         local_irq_restore(flags);
  65 }
  66
  67 void local_flush_tlb_mm(struct mm_struct *mm)
  68 {
  69         int cpu = smp_processor_id();
  70
  71         if (cpu_context(cpu, mm) != 0) {
  72 #ifdef DEBUG_TLB
  73                 printk("[tlbmm<%lu>]", (unsigned long)cpu_context(cpu, mm));
  74 #endif
  75                 drop_mmu_context(mm, cpu);
  76         }
  77 }
  78
  79 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  80                            unsigned long end)
  81 {
  82         struct mm_struct *mm = vma->vm_mm;
  83         int cpu = smp_processor_id();
  84
  85         if (cpu_context(cpu, mm) != 0) {
  86                 unsigned long size, flags;
  87
  88 #ifdef DEBUG_TLB
  89                 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
  90                         cpu_context(cpu, mm) & ASID_MASK, start, end);
  91 #endif
  92                 local_irq_save(flags);
  93                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  94                 if (size <= current_cpu_data.tlbsize) {
  95                         int oldpid = read_c0_entryhi() & ASID_MASK;
  96                         int newpid = cpu_context(cpu, mm) & ASID_MASK;
  97
  98                         start &= PAGE_MASK;
  99                         end += PAGE_SIZE - 1;
 100                         end &= PAGE_MASK;
 101                         while (start < end) {
 102                                 int idx;
 103
 104                                 write_c0_entryhi(start | newpid);
 105                                 start += PAGE_SIZE;     /* BARRIER */
 106                                 tlb_probe();
 107                                 idx = read_c0_index();
 108                                 write_c0_entrylo0(0);
 109                                 write_c0_entryhi(KSEG0);
 110                                 if (idx < 0)            /* BARRIER */
 111                                         continue;
 112                                 tlb_write_indexed();
 113                         }
 114                         write_c0_entryhi(oldpid);
 115                 } else {
 116                         drop_mmu_context(mm, cpu);
 117                 }
 118                 local_irq_restore(flags);
 119         }
 120 }
 121
 122 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 123 {
 124         unsigned long size, flags;
 125
 126 #ifdef DEBUG_TLB
 127         printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
 128 #endif
 129         local_irq_save(flags);
 130         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 131         if (size <= current_cpu_data.tlbsize) {
 132                 int pid = read_c0_entryhi();
 133
 134                 start &= PAGE_MASK;
 135                 end += PAGE_SIZE - 1;
 136                 end &= PAGE_MASK;
 137
 138                 while (start < end) {
 139                         int idx;
 140
 141                         write_c0_entryhi(start);
 142                         start += PAGE_SIZE;             /* BARRIER */
 143                         tlb_probe();
 144                         idx = read_c0_index();
 145                         write_c0_entrylo0(0);
 146                         write_c0_entryhi(KSEG0);
 147                         if (idx < 0)                    /* BARRIER */
 148                                 continue;
 149                         tlb_write_indexed();
 150                 }
 151                 write_c0_entryhi(pid);
 152         } else {
 153                 local_flush_tlb_all();
 154         }
 155         local_irq_restore(flags);
 156 }
 157
 158 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 159 {
 160         int cpu = smp_processor_id();
 161
 162         if (!vma || cpu_context(cpu, vma->vm_mm) != 0) {
 163                 unsigned long flags;
 164                 int oldpid, newpid, idx;
 165
 166 #ifdef DEBUG_TLB
 167                 printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
 168 #endif
 169                 newpid = cpu_context(cpu, vma->vm_mm) & ASID_MASK;
 170                 page &= PAGE_MASK;
 171                 local_irq_save(flags);
 172                 oldpid = read_c0_entryhi() & ASID_MASK;
 173                 write_c0_entryhi(page | newpid);
 174                 BARRIER;
 175                 tlb_probe();
 176                 idx = read_c0_index();
 177                 write_c0_entrylo0(0);
 178                 write_c0_entryhi(KSEG0);
 179                 if (idx < 0)                            /* BARRIER */
 180                         goto finish;
 181                 tlb_write_indexed();
 182
 183 finish:
 184                 write_c0_entryhi(oldpid);
 185                 local_irq_restore(flags);
 186         }
 187 }
 188
 189 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 190 {
 191         unsigned long flags;
 192         int idx, pid;
 193
 194         /*
 195          * Handle debugger faulting in for debugee.
 196          */
 197         if (current->active_mm != vma->vm_mm)
 198                 return;
 199
 200         pid = read_c0_entryhi() & ASID_MASK;
 201
 202 #ifdef DEBUG_TLB
 203         if ((pid != (cpu_context(cpu, vma->vm_mm) & ASID_MASK)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
 204                 printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
 205                        (cpu_context(cpu, vma->vm_mm)), pid);
 206         }
 207 #endif
 208
 209         local_irq_save(flags);
 210         address &= PAGE_MASK;
 211         write_c0_entryhi(address | pid);
 212         BARRIER;
 213         tlb_probe();
 214         idx = read_c0_index();
 215         write_c0_entrylo0(pte_val(pte));
 216         write_c0_entryhi(address | pid);
 217         if (idx < 0) {                                  /* BARRIER */
 218                 tlb_write_random();
 219         } else {
 220                 tlb_write_indexed();
 221         }
 222         write_c0_entryhi(pid);
 223         local_irq_restore(flags);
 224 }
 225
 226 void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 227                             unsigned long entryhi, unsigned long pagemask)
 228 {
 229         unsigned long flags;
 230         unsigned long old_ctx;
 231         static unsigned long wired = 0;
 232
 233         if (r3k_have_wired_reg) {                       /* TX39XX */
 234                 unsigned long old_pagemask;
 235                 unsigned long w;
 236
 237 #ifdef DEBUG_TLB
 238                 printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
 239                        entrylo0, entryhi, pagemask);
 240 #endif
 241
 242                 local_irq_save(flags);
 243                 /* Save old context and create impossible VPN2 value */
 244                 old_ctx = read_c0_entryhi() & ASID_MASK;
 245                 old_pagemask = read_c0_pagemask();
 246                 w = read_c0_wired();
 247                 write_c0_wired(w + 1);
 248                 write_c0_index(w << 8);
 249                 write_c0_pagemask(pagemask);
 250                 write_c0_entryhi(entryhi);
 251                 write_c0_entrylo0(entrylo0);
 252                 BARRIER;
 253                 tlb_write_indexed();
 254
 255                 write_c0_entryhi(old_ctx);
 256                 write_c0_pagemask(old_pagemask);
 257                 local_flush_tlb_all();
 258                 local_irq_restore(flags);
 259
 260         } else if (wired < 8) {
 261 #ifdef DEBUG_TLB
 262                 printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
 263                        entrylo0, entryhi);
 264 #endif
 265
 266                 local_irq_save(flags);
 267                 old_ctx = read_c0_entryhi() & ASID_MASK;
 268                 write_c0_entrylo0(entrylo0);
 269                 write_c0_entryhi(entryhi);
 270                 write_c0_index(wired);
 271                 wired++;                                /* BARRIER */
 272                 tlb_write_indexed();
 273                 write_c0_entryhi(old_ctx);
 274                 local_flush_tlb_all();
 275                 local_irq_restore(flags);
 276         }
 277 }
 278
 279 void __cpuinit tlb_init(void)
 280 {
 281         local_flush_tlb_all();
 282
 283         build_tlb_refill_handler();
 284 }