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/pgtable.h>
  20 #include <asm/cpuinfo.h>
  21
  22 #define TLB_INDEX_MASK          \
  23         ((((1UL << (cpuinfo.tlb_ptr_sz - cpuinfo.tlb_num_ways_log2))) - 1) \
  24                 << PAGE_SHIFT)
  25
  26 /* Used as illegal PHYS_ADDR for TLB mappings
  27  */
  28 #define MAX_PHYS_ADDR 0
  29
  30 static void get_misc_and_pid(unsigned long *misc, unsigned long *pid)
  31 {
  32         *misc  = RDCTL(CTL_TLBMISC);
  33         *misc &= (TLBMISC_PID | TLBMISC_WAY);
  34         *pid  = *misc & TLBMISC_PID;
  35 }
  36
  37 /*
  38  * All entries common to a mm share an asid.  To effectively flush these
  39  * entries, we just bump the asid.
  40  */
  41 void flush_tlb_mm(struct mm_struct *mm)
  42 {
  43         if (current->mm == mm)
  44                 flush_tlb_all();
  45         else
  46                 memset(&mm->context, 0, sizeof(mm_context_t));
  47 }
  48
  49 /*
  50  * This one is only used for pages with the global bit set so we don't care
  51  * much about the ASID.
  52  */
  53 void flush_tlb_one_pid(unsigned long addr, unsigned long mmu_pid)
  54 {
  55         unsigned int way;
  56         unsigned long org_misc, pid_misc;
  57
  58         pr_debug("Flush tlb-entry for vaddr=%#lx\n", addr);
  59
  60         /* remember pid/way until we return. */
  61         get_misc_and_pid(&org_misc, &pid_misc);
  62
  63         WRCTL(CTL_PTEADDR, (addr >> PAGE_SHIFT) << 2);
  64
  65         for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
  66                 unsigned long pteaddr;
  67                 unsigned long tlbmisc;
  68                 unsigned long pid;
  69
  70                 tlbmisc = pid_misc | TLBMISC_RD | (way << TLBMISC_WAY_SHIFT);
  71                 WRCTL(CTL_TLBMISC, tlbmisc);
  72                 pteaddr = RDCTL(CTL_PTEADDR);
  73                 tlbmisc = RDCTL(CTL_TLBMISC);
  74                 pid = (tlbmisc >> TLBMISC_PID_SHIFT) & TLBMISC_PID_MASK;
  75                 if (((((pteaddr >> 2) & 0xfffff)) == (addr >> PAGE_SHIFT)) &&
  76                                 pid == mmu_pid) {
  77                         unsigned long vaddr = CONFIG_NIOS2_IO_REGION_BASE +
  78                                 ((PAGE_SIZE * cpuinfo.tlb_num_lines) * way) +
  79                                 (addr & TLB_INDEX_MASK);
  80                         pr_debug("Flush entry by writing %#lx way=%dl pid=%ld\n",
  81                                 vaddr, way, (pid_misc >> TLBMISC_PID_SHIFT));
  82
  83                         WRCTL(CTL_PTEADDR, (vaddr >> 12) << 2);
  84                         tlbmisc = pid_misc | TLBMISC_WE |
  85                                 (way << TLBMISC_WAY_SHIFT);
  86                         WRCTL(CTL_TLBMISC, tlbmisc);
  87                         WRCTL(CTL_TLBACC, (MAX_PHYS_ADDR >> PAGE_SHIFT));
  88                 }
  89         }
  90
  91         WRCTL(CTL_TLBMISC, org_misc);
  92 }
  93
  94 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  95                         unsigned long end)
  96 {
  97         unsigned long mmu_pid = get_pid_from_context(&vma->vm_mm->context);
  98
  99         while (start < end) {
 100                 flush_tlb_one_pid(start, mmu_pid);
 101                 start += PAGE_SIZE;
 102         }
 103 }
 104
 105 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 106 {
 107         while (start < end) {
 108                 flush_tlb_one(start);
 109                 start += PAGE_SIZE;
 110         }
 111 }
 112
 113 /*
 114  * This one is only used for pages with the global bit set so we don't care
 115  * much about the ASID.
 116  */
 117 void flush_tlb_one(unsigned long addr)
 118 {
 119         unsigned int way;
 120         unsigned long org_misc, pid_misc;
 121
 122         pr_debug("Flush tlb-entry for vaddr=%#lx\n", addr);
 123
 124         /* remember pid/way until we return. */
 125         get_misc_and_pid(&org_misc, &pid_misc);
 126
 127         WRCTL(CTL_PTEADDR, (addr >> PAGE_SHIFT) << 2);
 128
 129         for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
 130                 unsigned long pteaddr;
 131                 unsigned long tlbmisc;
 132
 133                 tlbmisc = pid_misc | TLBMISC_RD | (way << TLBMISC_WAY_SHIFT);
 134                 WRCTL(CTL_TLBMISC, tlbmisc);
 135                 pteaddr = RDCTL(CTL_PTEADDR);
 136                 tlbmisc = RDCTL(CTL_TLBMISC);
 137
 138                 if ((((pteaddr >> 2) & 0xfffff)) == (addr >> PAGE_SHIFT)) {
 139                         unsigned long vaddr = CONFIG_NIOS2_IO_REGION_BASE +
 140                                 ((PAGE_SIZE * cpuinfo.tlb_num_lines) * way) +
 141                                 (addr & TLB_INDEX_MASK);
 142
 143                         pr_debug("Flush entry by writing %#lx way=%dl pid=%ld\n",
 144                                 vaddr, way, (pid_misc >> TLBMISC_PID_SHIFT));
 145
 146                         tlbmisc = pid_misc | TLBMISC_WE |
 147                                 (way << TLBMISC_WAY_SHIFT);
 148                         WRCTL(CTL_PTEADDR, (vaddr >> 12) << 2);
 149                         WRCTL(CTL_TLBMISC, tlbmisc);
 150                         WRCTL(CTL_TLBACC, (MAX_PHYS_ADDR >> PAGE_SHIFT));
 151                 }
 152         }
 153
 154         WRCTL(CTL_TLBMISC, org_misc);
 155 }
 156
 157 void dump_tlb_line(unsigned long line)
 158 {
 159         unsigned int way;
 160         unsigned long org_misc;
 161
 162         pr_debug("dump tlb-entries for line=%#lx (addr %08lx)\n", line,
 163                 line << (PAGE_SHIFT + cpuinfo.tlb_num_ways_log2));
 164
 165         /* remember pid/way until we return */
 166         org_misc = (RDCTL(CTL_TLBMISC) & (TLBMISC_PID | TLBMISC_WAY));
 167
 168         WRCTL(CTL_PTEADDR, line << 2);
 169
 170         for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
 171                 unsigned long pteaddr;
 172                 unsigned long tlbmisc;
 173                 unsigned long tlbacc;
 174
 175                 WRCTL(CTL_TLBMISC, TLBMISC_RD | (way << TLBMISC_WAY_SHIFT));
 176                 pteaddr = RDCTL(CTL_PTEADDR);
 177                 tlbmisc = RDCTL(CTL_TLBMISC);
 178                 tlbacc = RDCTL(CTL_TLBACC);
 179
 180                 if ((tlbacc << PAGE_SHIFT) != (MAX_PHYS_ADDR & PAGE_MASK)) {
 181                         pr_debug("-- way:%02x vpn:0x%08lx phys:0x%08lx pid:0x%02lx flags:%c%c%c%c%c\n",
 182                                 way,
 183                                 (pteaddr << (PAGE_SHIFT-2)),
 184                                 (tlbacc << PAGE_SHIFT),
 185                                 ((tlbmisc >> TLBMISC_PID_SHIFT) &
 186                                 TLBMISC_PID_MASK),
 187                                 (tlbacc & _PAGE_READ ? 'r' : '-'),
 188                                 (tlbacc & _PAGE_WRITE ? 'w' : '-'),
 189                                 (tlbacc & _PAGE_EXEC ? 'x' : '-'),
 190                                 (tlbacc & _PAGE_GLOBAL ? 'g' : '-'),
 191                                 (tlbacc & _PAGE_CACHED ? 'c' : '-'));
 192                 }
 193         }
 194
 195         WRCTL(CTL_TLBMISC, org_misc);
 196 }
 197
 198 void dump_tlb(void)
 199 {
 200         unsigned int i;
 201
 202         for (i = 0; i < cpuinfo.tlb_num_lines; i++)
 203                 dump_tlb_line(i);
 204 }
 205
 206 void flush_tlb_pid(unsigned long pid)
 207 {
 208         unsigned int line;
 209         unsigned int way;
 210         unsigned long org_misc, pid_misc;
 211
 212         /* remember pid/way until we return */
 213         get_misc_and_pid(&org_misc, &pid_misc);
 214
 215         for (line = 0; line < cpuinfo.tlb_num_lines; line++) {
 216                 WRCTL(CTL_PTEADDR, line << 2);
 217
 218                 for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
 219                         unsigned long pteaddr;
 220                         unsigned long tlbmisc;
 221                         unsigned long tlbacc;
 222
 223                         tlbmisc = pid_misc | TLBMISC_RD |
 224                                 (way << TLBMISC_WAY_SHIFT);
 225                         WRCTL(CTL_TLBMISC, tlbmisc);
 226                         pteaddr = RDCTL(CTL_PTEADDR);
 227                         tlbmisc = RDCTL(CTL_TLBMISC);
 228                         tlbacc = RDCTL(CTL_TLBACC);
 229
 230                         if (((tlbmisc>>TLBMISC_PID_SHIFT) & TLBMISC_PID_MASK)
 231                                 == pid) {
 232                                 tlbmisc = pid_misc | TLBMISC_WE |
 233                                         (way << TLBMISC_WAY_SHIFT);
 234                                 WRCTL(CTL_TLBMISC, tlbmisc);
 235                                 WRCTL(CTL_TLBACC,
 236                                         (MAX_PHYS_ADDR >> PAGE_SHIFT));
 237                         }
 238                 }
 239
 240                 WRCTL(CTL_TLBMISC, org_misc);
 241         }
 242 }
 243
 244 void flush_tlb_all(void)
 245 {
 246         int i;
 247         unsigned long vaddr = CONFIG_NIOS2_IO_REGION_BASE;
 248         unsigned int way;
 249         unsigned long org_misc, pid_misc, tlbmisc;
 250
 251         /* remember pid/way until we return */
 252         get_misc_and_pid(&org_misc, &pid_misc);
 253         pid_misc |= TLBMISC_WE;
 254
 255         /* Map each TLB entry to physcal address 0 with no-access and a
 256            bad ptbase */
 257         for (way = 0; way < cpuinfo.tlb_num_ways; way++) {
 258                 tlbmisc = pid_misc | (way << TLBMISC_WAY_SHIFT);
 259                 for (i = 0; i < cpuinfo.tlb_num_lines; i++) {
 260                         WRCTL(CTL_PTEADDR, ((vaddr) >> PAGE_SHIFT) << 2);
 261                         WRCTL(CTL_TLBMISC, tlbmisc);
 262                         WRCTL(CTL_TLBACC, (MAX_PHYS_ADDR >> PAGE_SHIFT));
 263                         vaddr += 1UL << 12;
 264                 }
 265         }
 266
 267         /* restore pid/way */
 268         WRCTL(CTL_TLBMISC, org_misc);
 269 }
 270
 271 void set_mmu_pid(unsigned long pid)
 272 {
 273         WRCTL(CTL_TLBMISC, (RDCTL(CTL_TLBMISC) & TLBMISC_WAY) |
 274                 ((pid & TLBMISC_PID_MASK) << TLBMISC_PID_SHIFT));
 275 }