linux/arch/mips/mm/tlb-r3k.c
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   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
  30extern 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
  40int r3k_have_wired_reg;         /* should be in cpu_data? */
  41
  42/* TLB operations. */
  43void 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
  67void 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
  79void 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
 122void 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
 158void 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
 183finish:
 184                write_c0_entryhi(oldpid);
 185                local_irq_restore(flags);
 186        }
 187}
 188
 189void __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
 226void __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
 279void __cpuinit tlb_init(void)
 280{
 281        local_flush_tlb_all();
 282
 283        build_tlb_refill_handler();
 284}
 285