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/mm.h>
  17
  18 #include <asm/page.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/mmu_context.h>
  21 #include <asm/system.h>
  22 #include <asm/isadep.h>
  23 #include <asm/io.h>
  24 #include <asm/bootinfo.h>
  25 #include <asm/cpu.h>
  26
  27 #undef DEBUG_TLB
  28
  29 extern void build_tlb_refill_handler(void);
  30
  31 /* CP0 hazard avoidance. */
  32 #define BARRIER                         \
  33         __asm__ __volatile__(           \
  34                 ".set   push\n\t"       \
  35                 ".set   noreorder\n\t"  \
  36                 "nop\n\t"               \
  37                 ".set   pop\n\t")
  38
  39 int r3k_have_wired_reg;         /* should be in cpu_data? */
  40
  41 /* TLB operations. */
  42 void local_flush_tlb_all(void)
  43 {
  44         unsigned long flags;
  45         unsigned long old_ctx;
  46         int entry;
  47
  48 #ifdef DEBUG_TLB
  49         printk("[tlball]");
  50 #endif
  51
  52         local_irq_save(flags);
  53         old_ctx = read_c0_entryhi() & ASID_MASK;
  54         write_c0_entrylo0(0);
  55         entry = r3k_have_wired_reg ? read_c0_wired() : 8;
  56         for (; entry < current_cpu_data.tlbsize; entry++) {
  57                 write_c0_index(entry << 8);
  58                 write_c0_entryhi((entry | 0x80000) << 12);
  59                 BARRIER;
  60                 tlb_write_indexed();
  61         }
  62         write_c0_entryhi(old_ctx);
  63         local_irq_restore(flags);
  64 }
  65
  66 void local_flush_tlb_mm(struct mm_struct *mm)
  67 {
  68         int cpu = smp_processor_id();
  69
  70         if (cpu_context(cpu, mm) != 0) {
  71 #ifdef DEBUG_TLB
  72                 printk("[tlbmm<%lu>]", (unsigned long)cpu_context(cpu, mm));
  73 #endif
  74                 drop_mmu_context(mm, cpu);
  75         }
  76 }
  77
  78 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  79                            unsigned long end)
  80 {
  81         struct mm_struct *mm = vma->vm_mm;
  82         int cpu = smp_processor_id();
  83
  84         if (cpu_context(cpu, mm) != 0) {
  85                 unsigned long flags;
  86                 int size;
  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 flags;
 125         int size;
 126
 127 #ifdef DEBUG_TLB
 128         printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
 129 #endif
 130         local_irq_save(flags);
 131         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 132         if (size <= current_cpu_data.tlbsize) {
 133                 int pid = read_c0_entryhi();
 134
 135                 start &= PAGE_MASK;
 136                 end += PAGE_SIZE - 1;
 137                 end &= PAGE_MASK;
 138
 139                 while (start < end) {
 140                         int idx;
 141
 142                         write_c0_entryhi(start);
 143                         start += PAGE_SIZE;             /* BARRIER */
 144                         tlb_probe();
 145                         idx = read_c0_index();
 146                         write_c0_entrylo0(0);
 147                         write_c0_entryhi(KSEG0);
 148                         if (idx < 0)                    /* BARRIER */
 149                                 continue;
 150                         tlb_write_indexed();
 151                 }
 152                 write_c0_entryhi(pid);
 153         } else {
 154                 local_flush_tlb_all();
 155         }
 156         local_irq_restore(flags);
 157 }
 158
 159 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 160 {
 161         int cpu = smp_processor_id();
 162
 163         if (!vma || cpu_context(cpu, vma->vm_mm) != 0) {
 164                 unsigned long flags;
 165                 int oldpid, newpid, idx;
 166
 167 #ifdef DEBUG_TLB
 168                 printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
 169 #endif
 170                 newpid = cpu_context(cpu, vma->vm_mm) & ASID_MASK;
 171                 page &= PAGE_MASK;
 172                 local_irq_save(flags);
 173                 oldpid = read_c0_entryhi() & ASID_MASK;
 174                 write_c0_entryhi(page | newpid);
 175                 BARRIER;
 176                 tlb_probe();
 177                 idx = read_c0_index();
 178                 write_c0_entrylo0(0);
 179                 write_c0_entryhi(KSEG0);
 180                 if (idx < 0)                            /* BARRIER */
 181                         goto finish;
 182                 tlb_write_indexed();
 183
 184 finish:
 185                 write_c0_entryhi(oldpid);
 186                 local_irq_restore(flags);
 187         }
 188 }
 189
 190 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 191 {
 192         unsigned long flags;
 193         int idx, pid;
 194
 195         /*
 196          * Handle debugger faulting in for debugee.
 197          */
 198         if (current->active_mm != vma->vm_mm)
 199                 return;
 200
 201         pid = read_c0_entryhi() & ASID_MASK;
 202
 203 #ifdef DEBUG_TLB
 204         if ((pid != (cpu_context(cpu, vma->vm_mm) & ASID_MASK)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
 205                 printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
 206                        (cpu_context(cpu, vma->vm_mm)), pid);
 207         }
 208 #endif
 209
 210         local_irq_save(flags);
 211         address &= PAGE_MASK;
 212         write_c0_entryhi(address | pid);
 213         BARRIER;
 214         tlb_probe();
 215         idx = read_c0_index();
 216         write_c0_entrylo0(pte_val(pte));
 217         write_c0_entryhi(address | pid);
 218         if (idx < 0) {                                  /* BARRIER */
 219                 tlb_write_random();
 220         } else {
 221                 tlb_write_indexed();
 222         }
 223         write_c0_entryhi(pid);
 224         local_irq_restore(flags);
 225 }
 226
 227 void __init add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 228                             unsigned long entryhi, unsigned long pagemask)
 229 {
 230         unsigned long flags;
 231         unsigned long old_ctx;
 232         static unsigned long wired = 0;
 233
 234         if (r3k_have_wired_reg) {                       /* TX39XX */
 235                 unsigned long old_pagemask;
 236                 unsigned long w;
 237
 238 #ifdef DEBUG_TLB
 239                 printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
 240                        entrylo0, entryhi, pagemask);
 241 #endif
 242
 243                 local_irq_save(flags);
 244                 /* Save old context and create impossible VPN2 value */
 245                 old_ctx = read_c0_entryhi() & ASID_MASK;
 246                 old_pagemask = read_c0_pagemask();
 247                 w = read_c0_wired();
 248                 write_c0_wired(w + 1);
 249                 write_c0_index(w << 8);
 250                 write_c0_pagemask(pagemask);
 251                 write_c0_entryhi(entryhi);
 252                 write_c0_entrylo0(entrylo0);
 253                 BARRIER;
 254                 tlb_write_indexed();
 255
 256                 write_c0_entryhi(old_ctx);
 257                 write_c0_pagemask(old_pagemask);
 258                 local_flush_tlb_all();
 259                 local_irq_restore(flags);
 260
 261         } else if (wired < 8) {
 262 #ifdef DEBUG_TLB
 263                 printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
 264                        entrylo0, entryhi);
 265 #endif
 266
 267                 local_irq_save(flags);
 268                 old_ctx = read_c0_entryhi() & ASID_MASK;
 269                 write_c0_entrylo0(entrylo0);
 270                 write_c0_entryhi(entryhi);
 271                 write_c0_index(wired);
 272                 wired++;                                /* BARRIER */
 273                 tlb_write_indexed();
 274                 write_c0_entryhi(old_ctx);
 275                 local_flush_tlb_all();
 276                 local_irq_restore(flags);
 277         }
 278 }
 279
 280 void __cpuinit tlb_init(void)
 281 {
 282         local_flush_tlb_all();
 283
 284         build_tlb_refill_handler();
 285 }