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 (davem@davemloft.net)
   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/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/smp.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/tlbmisc.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 size, flags;
  86
  87 #ifdef DEBUG_TLB
  88                 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
  89                         cpu_context(cpu, mm) & ASID_MASK, start, end);
  90 #endif
  91                 local_irq_save(flags);
  92                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  93                 if (size <= current_cpu_data.tlbsize) {
  94                         int oldpid = read_c0_entryhi() & ASID_MASK;
  95                         int newpid = cpu_context(cpu, mm) & ASID_MASK;
  96
  97                         start &= PAGE_MASK;
  98                         end += PAGE_SIZE - 1;
  99                         end &= PAGE_MASK;
 100                         while (start < end) {
 101                                 int idx;
 102
 103                                 write_c0_entryhi(start | newpid);
 104                                 start += PAGE_SIZE;     /* BARRIER */
 105                                 tlb_probe();
 106                                 idx = read_c0_index();
 107                                 write_c0_entrylo0(0);
 108                                 write_c0_entryhi(KSEG0);
 109                                 if (idx < 0)            /* BARRIER */
 110                                         continue;
 111                                 tlb_write_indexed();
 112                         }
 113                         write_c0_entryhi(oldpid);
 114                 } else {
 115                         drop_mmu_context(mm, cpu);
 116                 }
 117                 local_irq_restore(flags);
 118         }
 119 }
 120
 121 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 122 {
 123         unsigned long size, flags;
 124
 125 #ifdef DEBUG_TLB
 126         printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
 127 #endif
 128         local_irq_save(flags);
 129         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 130         if (size <= current_cpu_data.tlbsize) {
 131                 int pid = read_c0_entryhi();
 132
 133                 start &= PAGE_MASK;
 134                 end += PAGE_SIZE - 1;
 135                 end &= PAGE_MASK;
 136
 137                 while (start < end) {
 138                         int idx;
 139
 140                         write_c0_entryhi(start);
 141                         start += PAGE_SIZE;             /* BARRIER */
 142                         tlb_probe();
 143                         idx = read_c0_index();
 144                         write_c0_entrylo0(0);
 145                         write_c0_entryhi(KSEG0);
 146                         if (idx < 0)                    /* BARRIER */
 147                                 continue;
 148                         tlb_write_indexed();
 149                 }
 150                 write_c0_entryhi(pid);
 151         } else {
 152                 local_flush_tlb_all();
 153         }
 154         local_irq_restore(flags);
 155 }
 156
 157 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 158 {
 159         int cpu = smp_processor_id();
 160
 161         if (!vma || cpu_context(cpu, vma->vm_mm) != 0) {
 162                 unsigned long flags;
 163                 int oldpid, newpid, idx;
 164
 165 #ifdef DEBUG_TLB
 166                 printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
 167 #endif
 168                 newpid = cpu_context(cpu, vma->vm_mm) & ASID_MASK;
 169                 page &= PAGE_MASK;
 170                 local_irq_save(flags);
 171                 oldpid = read_c0_entryhi() & ASID_MASK;
 172                 write_c0_entryhi(page | newpid);
 173                 BARRIER;
 174                 tlb_probe();
 175                 idx = read_c0_index();
 176                 write_c0_entrylo0(0);
 177                 write_c0_entryhi(KSEG0);
 178                 if (idx < 0)                            /* BARRIER */
 179                         goto finish;
 180                 tlb_write_indexed();
 181
 182 finish:
 183                 write_c0_entryhi(oldpid);
 184                 local_irq_restore(flags);
 185         }
 186 }
 187
 188 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 189 {
 190         unsigned long flags;
 191         int idx, pid;
 192
 193         /*
 194          * Handle debugger faulting in for debugee.
 195          */
 196         if (current->active_mm != vma->vm_mm)
 197                 return;
 198
 199         pid = read_c0_entryhi() & ASID_MASK;
 200
 201 #ifdef DEBUG_TLB
 202         if ((pid != (cpu_context(cpu, vma->vm_mm) & ASID_MASK)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
 203                 printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
 204                        (cpu_context(cpu, vma->vm_mm)), pid);
 205         }
 206 #endif
 207
 208         local_irq_save(flags);
 209         address &= PAGE_MASK;
 210         write_c0_entryhi(address | pid);
 211         BARRIER;
 212         tlb_probe();
 213         idx = read_c0_index();
 214         write_c0_entrylo0(pte_val(pte));
 215         write_c0_entryhi(address | pid);
 216         if (idx < 0) {                                  /* BARRIER */
 217                 tlb_write_random();
 218         } else {
 219                 tlb_write_indexed();
 220         }
 221         write_c0_entryhi(pid);
 222         local_irq_restore(flags);
 223 }
 224
 225 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 226                      unsigned long entryhi, unsigned long pagemask)
 227 {
 228         unsigned long flags;
 229         unsigned long old_ctx;
 230         static unsigned long wired = 0;
 231
 232         if (r3k_have_wired_reg) {                       /* TX39XX */
 233                 unsigned long old_pagemask;
 234                 unsigned long w;
 235
 236 #ifdef DEBUG_TLB
 237                 printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
 238                        entrylo0, entryhi, pagemask);
 239 #endif
 240
 241                 local_irq_save(flags);
 242                 /* Save old context and create impossible VPN2 value */
 243                 old_ctx = read_c0_entryhi() & ASID_MASK;
 244                 old_pagemask = read_c0_pagemask();
 245                 w = read_c0_wired();
 246                 write_c0_wired(w + 1);
 247                 write_c0_index(w << 8);
 248                 write_c0_pagemask(pagemask);
 249                 write_c0_entryhi(entryhi);
 250                 write_c0_entrylo0(entrylo0);
 251                 BARRIER;
 252                 tlb_write_indexed();
 253
 254                 write_c0_entryhi(old_ctx);
 255                 write_c0_pagemask(old_pagemask);
 256                 local_flush_tlb_all();
 257                 local_irq_restore(flags);
 258
 259         } else if (wired < 8) {
 260 #ifdef DEBUG_TLB
 261                 printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
 262                        entrylo0, entryhi);
 263 #endif
 264
 265                 local_irq_save(flags);
 266                 old_ctx = read_c0_entryhi() & ASID_MASK;
 267                 write_c0_entrylo0(entrylo0);
 268                 write_c0_entryhi(entryhi);
 269                 write_c0_index(wired);
 270                 wired++;                                /* BARRIER */
 271                 tlb_write_indexed();
 272                 write_c0_entryhi(old_ctx);
 273                 local_flush_tlb_all();
 274                 local_irq_restore(flags);
 275         }
 276 }
 277
 278 void tlb_init(void)
 279 {
 280         local_flush_tlb_all();
 281
 282         build_tlb_refill_handler();
 283 }