LXR linux/arch/nios2/mm/tlb.c

   1/*
   2 * Nios2 TLB handling
   3 *
   4 * Copyright (C) 2009, Wind River Systems Inc
   5 *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
   6 *
   7 * This file is subject to the terms and conditions of the GNU General Public
   8 * License.  See the file "COPYING" in the main directory of this archive
   9 * for more details.
  10 */
  11
  12#include <linux/init.h>
  13#include <linux/sched.h>
  14#include <linux/mm.h>
  15#include <linux/pagemap.h>
  16
  17#include <asm/tlb.h>
  18#include <asm/mmu_context.h>
  19#include <asm/cpuinfo.h>
  20
  21#define TLB_INDEX_MASK          \
  22        ((((1UL << (cpuinfo.tlb_ptr_sz - cpuinfo.tlb_num_ways_log2))) - 1) \
  23                << PAGE_SHIFT)
  24
  25static void get_misc_and_pid(unsigned long *misc, unsigned long *pid)
  26{
  27        *misc  = RDCTL(CTL_TLBMISC);
  28        *misc &= (TLBMISC_PID | TLBMISC_WAY);
  29        *pid  = *misc & TLBMISC_PID;
  30}
  31
  32/*
  33 * This provides a PTEADDR value for addr that will cause a TLB miss
  34 * (fast TLB miss). TLB invalidation replaces entries with this value.
  35 */
  36static unsigned long pteaddr_invalid(unsigned long addr)
  37{
  38        return ((addr | 0xC0000000UL) >> PAGE_SHIFT) << 2;
  39}
  40
  41/*
  42 * This one is only used for pages with the global bit set so we don't care
  43 * much about the ASID.
  44 */
  45static void replace_tlb_one_pid(unsigned long addr, unsigned long mmu_pid, unsigned long tlbacc)
  46{
  47        unsigned int way;
  48        unsigned long org_misc, pid_misc;
  49
  50        /* remember pid/way until we return. */
  51        get_misc_and_pid(&org_misc, &pid_misc);
  52
  53        WRCTL(CTL_PTEADDR, (addr >> PAGE_SHIFT) << 2);
  54
  55        for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
  56                unsigned long pteaddr;
  57                unsigned long tlbmisc;
  58                unsigned long pid;
  59
  60                tlbmisc = TLBMISC_RD | (way << TLBMISC_WAY_SHIFT);
  61                WRCTL(CTL_TLBMISC, tlbmisc);
  62
  63                pteaddr = RDCTL(CTL_PTEADDR);
  64                if (((pteaddr >> 2) & 0xfffff) != (addr >> PAGE_SHIFT))
  65                        continue;
  66
  67                tlbmisc = RDCTL(CTL_TLBMISC);
  68                pid = (tlbmisc >> TLBMISC_PID_SHIFT) & TLBMISC_PID_MASK;
  69                if (pid != mmu_pid)
  70                        continue;
  71
  72                tlbmisc = (mmu_pid << TLBMISC_PID_SHIFT) | TLBMISC_WE |
  73                          (way << TLBMISC_WAY_SHIFT);
  74                WRCTL(CTL_TLBMISC, tlbmisc);
  75                if (tlbacc == 0)
  76                        WRCTL(CTL_PTEADDR, pteaddr_invalid(addr));
  77                WRCTL(CTL_TLBACC, tlbacc);
  78                /*
  79                 * There should be only a single entry that maps a
  80                 * particular {address,pid} so break after a match.
  81                 */
  82                break;
  83        }
  84
  85        WRCTL(CTL_TLBMISC, org_misc);
  86}
  87
  88static void flush_tlb_one_pid(unsigned long addr, unsigned long mmu_pid)
  89{
  90        pr_debug("Flush tlb-entry for vaddr=%#lx\n", addr);
  91
  92        replace_tlb_one_pid(addr, mmu_pid, 0);
  93}
  94
  95static void reload_tlb_one_pid(unsigned long addr, unsigned long mmu_pid, pte_t pte)
  96{
  97        pr_debug("Reload tlb-entry for vaddr=%#lx\n", addr);
  98
  99        replace_tlb_one_pid(addr, mmu_pid, pte_val(pte));
 100}
 101
 102void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 103                        unsigned long end)
 104{
 105        unsigned long mmu_pid = get_pid_from_context(&vma->vm_mm->context);
 106
 107        while (start < end) {
 108                flush_tlb_one_pid(start, mmu_pid);
 109                start += PAGE_SIZE;
 110        }
 111}
 112
 113void reload_tlb_page(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
 114{
 115        unsigned long mmu_pid = get_pid_from_context(&vma->vm_mm->context);
 116
 117        reload_tlb_one_pid(addr, mmu_pid, pte);
 118}
 119
 120/*
 121 * This one is only used for pages with the global bit set so we don't care
 122 * much about the ASID.
 123 */
 124static void flush_tlb_one(unsigned long addr)
 125{
 126        unsigned int way;
 127        unsigned long org_misc, pid_misc;
 128
 129        pr_debug("Flush tlb-entry for vaddr=%#lx\n", addr);
 130
 131        /* remember pid/way until we return. */
 132        get_misc_and_pid(&org_misc, &pid_misc);
 133
 134        WRCTL(CTL_PTEADDR, (addr >> PAGE_SHIFT) << 2);
 135
 136        for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
 137                unsigned long pteaddr;
 138                unsigned long tlbmisc;
 139
 140                tlbmisc = TLBMISC_RD | (way << TLBMISC_WAY_SHIFT);
 141                WRCTL(CTL_TLBMISC, tlbmisc);
 142
 143                pteaddr = RDCTL(CTL_PTEADDR);
 144                if (((pteaddr >> 2) & 0xfffff) != (addr >> PAGE_SHIFT))
 145                        continue;
 146
 147                pr_debug("Flush entry by writing way=%dl pid=%ld\n",
 148                         way, (pid_misc >> TLBMISC_PID_SHIFT));
 149
 150                tlbmisc = TLBMISC_WE | (way << TLBMISC_WAY_SHIFT);
 151                WRCTL(CTL_TLBMISC, tlbmisc);
 152                WRCTL(CTL_PTEADDR, pteaddr_invalid(addr));
 153                WRCTL(CTL_TLBACC, 0);
 154        }
 155
 156        WRCTL(CTL_TLBMISC, org_misc);
 157}
 158
 159void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 160{
 161        while (start < end) {
 162                flush_tlb_one(start);
 163                start += PAGE_SIZE;
 164        }
 165}
 166
 167void dump_tlb_line(unsigned long line)
 168{
 169        unsigned int way;
 170        unsigned long org_misc;
 171
 172        pr_debug("dump tlb-entries for line=%#lx (addr %08lx)\n", line,
 173                line << (PAGE_SHIFT + cpuinfo.tlb_num_ways_log2));
 174
 175        /* remember pid/way until we return */
 176        org_misc = (RDCTL(CTL_TLBMISC) & (TLBMISC_PID | TLBMISC_WAY));
 177
 178        WRCTL(CTL_PTEADDR, line << 2);
 179
 180        for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
 181                unsigned long pteaddr;
 182                unsigned long tlbmisc;
 183                unsigned long tlbacc;
 184
 185                WRCTL(CTL_TLBMISC, TLBMISC_RD | (way << TLBMISC_WAY_SHIFT));
 186                pteaddr = RDCTL(CTL_PTEADDR);
 187                tlbmisc = RDCTL(CTL_TLBMISC);
 188                tlbacc = RDCTL(CTL_TLBACC);
 189
 190                if ((tlbacc << PAGE_SHIFT) != 0) {
 191                        pr_debug("-- way:%02x vpn:0x%08lx phys:0x%08lx pid:0x%02lx flags:%c%c%c%c%c\n",
 192                                way,
 193                                (pteaddr << (PAGE_SHIFT-2)),
 194                                (tlbacc << PAGE_SHIFT),
 195                                ((tlbmisc >> TLBMISC_PID_SHIFT) &
 196                                TLBMISC_PID_MASK),
 197                                (tlbacc & _PAGE_READ ? 'r' : '-'),
 198                                (tlbacc & _PAGE_WRITE ? 'w' : '-'),
 199                                (tlbacc & _PAGE_EXEC ? 'x' : '-'),
 200                                (tlbacc & _PAGE_GLOBAL ? 'g' : '-'),
 201                                (tlbacc & _PAGE_CACHED ? 'c' : '-'));
 202                }
 203        }
 204
 205        WRCTL(CTL_TLBMISC, org_misc);
 206}
 207
 208void dump_tlb(void)
 209{
 210        unsigned int i;
 211
 212        for (i = 0; i < cpuinfo.tlb_num_lines; i++)
 213                dump_tlb_line(i);
 214}
 215
 216void flush_tlb_pid(unsigned long mmu_pid)
 217{
 218        unsigned long addr = 0;
 219        unsigned int line;
 220        unsigned int way;
 221        unsigned long org_misc, pid_misc;
 222
 223        /* remember pid/way until we return */
 224        get_misc_and_pid(&org_misc, &pid_misc);
 225
 226        for (line = 0; line < cpuinfo.tlb_num_lines; line++) {
 227                WRCTL(CTL_PTEADDR, pteaddr_invalid(addr));
 228
 229                for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
 230                        unsigned long tlbmisc;
 231                        unsigned long pid;
 232
 233                        tlbmisc = TLBMISC_RD | (way << TLBMISC_WAY_SHIFT);
 234                        WRCTL(CTL_TLBMISC, tlbmisc);
 235                        tlbmisc = RDCTL(CTL_TLBMISC);
 236                        pid = (tlbmisc >> TLBMISC_PID_SHIFT) & TLBMISC_PID_MASK;
 237                        if (pid != mmu_pid)
 238                                continue;
 239
 240                        tlbmisc = TLBMISC_WE | (way << TLBMISC_WAY_SHIFT);
 241                        WRCTL(CTL_TLBMISC, tlbmisc);
 242                        WRCTL(CTL_TLBACC, 0);
 243                }
 244
 245                addr += PAGE_SIZE;
 246        }
 247
 248        WRCTL(CTL_TLBMISC, org_misc);
 249}
 250
 251/*
 252 * All entries common to a mm share an asid.  To effectively flush these
 253 * entries, we just bump the asid.
 254 */
 255void flush_tlb_mm(struct mm_struct *mm)
 256{
 257        if (current->mm == mm) {
 258                unsigned long mmu_pid = get_pid_from_context(&mm->context);
 259                flush_tlb_pid(mmu_pid);
 260        } else {
 261                memset(&mm->context, 0, sizeof(mm_context_t));
 262        }
 263}
 264
 265void flush_tlb_all(void)
 266{
 267        unsigned long addr = 0;
 268        unsigned int line;
 269        unsigned int way;
 270        unsigned long org_misc, pid_misc;
 271
 272        /* remember pid/way until we return */
 273        get_misc_and_pid(&org_misc, &pid_misc);
 274
 275        /* Start at way 0, way is auto-incremented after each TLBACC write */
 276        WRCTL(CTL_TLBMISC, TLBMISC_WE);
 277
 278        /* Map each TLB entry to physcal address 0 with no-access and a
 279           bad ptbase */
 280        for (line = 0; line < cpuinfo.tlb_num_lines; line++) {
 281                WRCTL(CTL_PTEADDR, pteaddr_invalid(addr));
 282                for (way = 0; way < cpuinfo.tlb_num_ways; way++)
 283                        WRCTL(CTL_TLBACC, 0);
 284
 285                addr += PAGE_SIZE;
 286        }
 287
 288        /* restore pid/way */
 289        WRCTL(CTL_TLBMISC, org_misc);
 290}
 291
 292void set_mmu_pid(unsigned long pid)
 293{
 294        unsigned long tlbmisc;
 295
 296        tlbmisc = RDCTL(CTL_TLBMISC);
 297        tlbmisc = (tlbmisc & TLBMISC_WAY);
 298        tlbmisc |= (pid & TLBMISC_PID_MASK) << TLBMISC_PID_SHIFT;
 299        WRCTL(CTL_TLBMISC, tlbmisc);
 300}
 301