arch/avr32/mm/tlb.c

   1 /*
   2  * AVR32 TLB operations
   3  *
   4  * Copyright (C) 2004-2006 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/mm.h>
  11
  12 #include <asm/mmu_context.h>
  13
  14 #define _TLBEHI_I       0x100
  15
  16 void show_dtlb_entry(unsigned int index)
  17 {
  18         unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
  19         unsigned long flags;
  20
  21         local_irq_save(flags);
  22         mmucr_save = sysreg_read(MMUCR);
  23         tlbehi_save = sysreg_read(TLBEHI);
  24         mmucr = mmucr_save & 0x13;
  25         mmucr |= index << 14;
  26         sysreg_write(MMUCR, mmucr);
  27
  28         asm volatile("tlbr" : : : "memory");
  29         cpu_sync_pipeline();
  30
  31         tlbehi = sysreg_read(TLBEHI);
  32         tlbelo = sysreg_read(TLBELO);
  33
  34         printk("%2u: %c %c %02x   %05x %05x %o  %o  %c %c %c %c\n",
  35                index,
  36                (tlbehi & 0x200)?'1':'0',
  37                (tlbelo & 0x100)?'1':'0',
  38                (tlbehi & 0xff),
  39                (tlbehi >> 12), (tlbelo >> 12),
  40                (tlbelo >> 4) & 7, (tlbelo >> 2) & 3,
  41                (tlbelo & 0x200)?'1':'0',
  42                (tlbelo & 0x080)?'1':'0',
  43                (tlbelo & 0x001)?'1':'0',
  44                (tlbelo & 0x002)?'1':'0');
  45
  46         sysreg_write(MMUCR, mmucr_save);
  47         sysreg_write(TLBEHI, tlbehi_save);
  48         cpu_sync_pipeline();
  49         local_irq_restore(flags);
  50 }
  51
  52 void dump_dtlb(void)
  53 {
  54         unsigned int i;
  55
  56         printk("ID  V G ASID VPN   PFN   AP SZ C B W D\n");
  57         for (i = 0; i < 32; i++)
  58                 show_dtlb_entry(i);
  59 }
  60
  61 static unsigned long last_mmucr;
  62
  63 static inline void set_replacement_pointer(unsigned shift)
  64 {
  65         unsigned long mmucr, mmucr_save;
  66
  67         mmucr = mmucr_save = sysreg_read(MMUCR);
  68
  69         /* Does this mapping already exist? */
  70         __asm__ __volatile__(
  71                 "       tlbs\n"
  72                 "       mfsr %0, %1"
  73                 : "=r"(mmucr)
  74                 : "i"(SYSREG_MMUCR));
  75
  76         if (mmucr & SYSREG_BIT(MMUCR_N)) {
  77                 /* Not found -- pick a not-recently-accessed entry */
  78                 unsigned long rp;
  79                 unsigned long tlbar = sysreg_read(TLBARLO);
  80
  81                 rp = 32 - fls(tlbar);
  82                 if (rp == 32) {
  83                         rp = 0;
  84                         sysreg_write(TLBARLO, -1L);
  85                 }
  86
  87                 mmucr &= 0x13;
  88                 mmucr |= (rp << shift);
  89
  90                 sysreg_write(MMUCR, mmucr);
  91         }
  92
  93         last_mmucr = mmucr;
  94 }
  95
  96 static void update_dtlb(unsigned long address, pte_t pte, unsigned long asid)
  97 {
  98         unsigned long vpn;
  99
 100         vpn = (address & MMU_VPN_MASK) | _TLBEHI_VALID | asid;
 101         sysreg_write(TLBEHI, vpn);
 102         cpu_sync_pipeline();
 103
 104         set_replacement_pointer(14);
 105
 106         sysreg_write(TLBELO, pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK);
 107
 108         /* Let's go */
 109         asm volatile("nop\n\ttlbw" : : : "memory");
 110         cpu_sync_pipeline();
 111 }
 112
 113 void update_mmu_cache(struct vm_area_struct *vma,
 114                       unsigned long address, pte_t pte)
 115 {
 116         unsigned long flags;
 117
 118         /* ptrace may call this routine */
 119         if (vma && current->active_mm != vma->vm_mm)
 120                 return;
 121
 122         local_irq_save(flags);
 123         update_dtlb(address, pte, get_asid());
 124         local_irq_restore(flags);
 125 }
 126
 127 void __flush_tlb_page(unsigned long asid, unsigned long page)
 128 {
 129         unsigned long mmucr, tlbehi;
 130
 131         page |= asid;
 132         sysreg_write(TLBEHI, page);
 133         cpu_sync_pipeline();
 134         asm volatile("tlbs");
 135         mmucr = sysreg_read(MMUCR);
 136
 137         if (!(mmucr & SYSREG_BIT(MMUCR_N))) {
 138                 unsigned long tlbarlo;
 139                 unsigned long entry;
 140
 141                 /* Clear the "valid" bit */
 142                 tlbehi = sysreg_read(TLBEHI);
 143                 tlbehi &= ~_TLBEHI_VALID;
 144                 sysreg_write(TLBEHI, tlbehi);
 145                 cpu_sync_pipeline();
 146
 147                 /* mark the entry as "not accessed" */
 148                 entry = (mmucr >> 14) & 0x3f;
 149                 tlbarlo = sysreg_read(TLBARLO);
 150                 tlbarlo |= (0x80000000 >> entry);
 151                 sysreg_write(TLBARLO, tlbarlo);
 152
 153                 /* update the entry with valid bit clear */
 154                 asm volatile("tlbw");
 155                 cpu_sync_pipeline();
 156         }
 157 }
 158
 159 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 160 {
 161         if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) {
 162                 unsigned long flags, asid;
 163                 unsigned long saved_asid = MMU_NO_ASID;
 164
 165                 asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK;
 166                 page &= PAGE_MASK;
 167
 168                 local_irq_save(flags);
 169                 if (vma->vm_mm != current->mm) {
 170                         saved_asid = get_asid();
 171                         set_asid(asid);
 172                 }
 173
 174                 __flush_tlb_page(asid, page);
 175
 176                 if (saved_asid != MMU_NO_ASID)
 177                         set_asid(saved_asid);
 178                 local_irq_restore(flags);
 179         }
 180 }
 181
 182 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 183                      unsigned long end)
 184 {
 185         struct mm_struct *mm = vma->vm_mm;
 186
 187         if (mm->context != NO_CONTEXT) {
 188                 unsigned long flags;
 189                 int size;
 190
 191                 local_irq_save(flags);
 192                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 193                 if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
 194                         mm->context = NO_CONTEXT;
 195                         if (mm == current->mm)
 196                                 activate_context(mm);
 197                 } else {
 198                         unsigned long asid = mm->context & MMU_CONTEXT_ASID_MASK;
 199                         unsigned long saved_asid = MMU_NO_ASID;
 200
 201                         start &= PAGE_MASK;
 202                         end += (PAGE_SIZE - 1);
 203                         end &= PAGE_MASK;
 204                         if (mm != current->mm) {
 205                                 saved_asid = get_asid();
 206                                 set_asid(asid);
 207                         }
 208
 209                         while (start < end) {
 210                                 __flush_tlb_page(asid, start);
 211                                 start += PAGE_SIZE;
 212                         }
 213                         if (saved_asid != MMU_NO_ASID)
 214                                 set_asid(saved_asid);
 215                 }
 216                 local_irq_restore(flags);
 217         }
 218 }
 219
 220 /*
 221  * TODO: If this is only called for addresses > TASK_SIZE, we can probably
 222  * skip the ASID stuff and just use the Global bit...
 223  */
 224 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 225 {
 226         unsigned long flags;
 227         int size;
 228
 229         local_irq_save(flags);
 230         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 231         if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
 232                 flush_tlb_all();
 233         } else {
 234                 unsigned long asid = init_mm.context & MMU_CONTEXT_ASID_MASK;
 235                 unsigned long saved_asid = get_asid();
 236
 237                 start &= PAGE_MASK;
 238                 end += (PAGE_SIZE - 1);
 239                 end &= PAGE_MASK;
 240                 set_asid(asid);
 241                 while (start < end) {
 242                         __flush_tlb_page(asid, start);
 243                         start += PAGE_SIZE;
 244                 }
 245                 set_asid(saved_asid);
 246         }
 247         local_irq_restore(flags);
 248 }
 249
 250 void flush_tlb_mm(struct mm_struct *mm)
 251 {
 252         /* Invalidate all TLB entries of this process by getting a new ASID */
 253         if (mm->context != NO_CONTEXT) {
 254                 unsigned long flags;
 255
 256                 local_irq_save(flags);
 257                 mm->context = NO_CONTEXT;
 258                 if (mm == current->mm)
 259                         activate_context(mm);
 260                 local_irq_restore(flags);
 261         }
 262 }
 263
 264 void flush_tlb_all(void)
 265 {
 266         unsigned long flags;
 267
 268         local_irq_save(flags);
 269         sysreg_write(MMUCR, sysreg_read(MMUCR) | SYSREG_BIT(MMUCR_I));
 270         local_irq_restore(flags);
 271 }
 272
 273 #ifdef CONFIG_PROC_FS
 274
 275 #include <linux/seq_file.h>
 276 #include <linux/proc_fs.h>
 277 #include <linux/init.h>
 278
 279 static void *tlb_start(struct seq_file *tlb, loff_t *pos)
 280 {
 281         static unsigned long tlb_index;
 282
 283         if (*pos >= 32)
 284                 return NULL;
 285
 286         tlb_index = 0;
 287         return &tlb_index;
 288 }
 289
 290 static void *tlb_next(struct seq_file *tlb, void *v, loff_t *pos)
 291 {
 292         unsigned long *index = v;
 293
 294         if (*index >= 31)
 295                 return NULL;
 296
 297         ++*pos;
 298         ++*index;
 299         return index;
 300 }
 301
 302 static void tlb_stop(struct seq_file *tlb, void *v)
 303 {
 304
 305 }
 306
 307 static int tlb_show(struct seq_file *tlb, void *v)
 308 {
 309         unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
 310         unsigned long flags;
 311         unsigned long *index = v;
 312
 313         if (*index == 0)
 314                 seq_puts(tlb, "ID  V G ASID VPN   PFN   AP SZ C B W D\n");
 315
 316         BUG_ON(*index >= 32);
 317
 318         local_irq_save(flags);
 319         mmucr_save = sysreg_read(MMUCR);
 320         tlbehi_save = sysreg_read(TLBEHI);
 321         mmucr = mmucr_save & 0x13;
 322         mmucr |= *index << 14;
 323         sysreg_write(MMUCR, mmucr);
 324
 325         asm volatile("tlbr" : : : "memory");
 326         cpu_sync_pipeline();
 327
 328         tlbehi = sysreg_read(TLBEHI);
 329         tlbelo = sysreg_read(TLBELO);
 330
 331         sysreg_write(MMUCR, mmucr_save);
 332         sysreg_write(TLBEHI, tlbehi_save);
 333         cpu_sync_pipeline();
 334         local_irq_restore(flags);
 335
 336         seq_printf(tlb, "%2lu: %c %c %02x   %05x %05x %o  %o  %c %c %c %c\n",
 337                *index,
 338                (tlbehi & 0x200)?'1':'0',
 339                (tlbelo & 0x100)?'1':'0',
 340                (tlbehi & 0xff),
 341                (tlbehi >> 12), (tlbelo >> 12),
 342                (tlbelo >> 4) & 7, (tlbelo >> 2) & 3,
 343                (tlbelo & 0x200)?'1':'0',
 344                (tlbelo & 0x080)?'1':'0',
 345                (tlbelo & 0x001)?'1':'0',
 346                (tlbelo & 0x002)?'1':'0');
 347
 348         return 0;
 349 }
 350
 351 static const struct seq_operations tlb_ops = {
 352         .start          = tlb_start,
 353         .next           = tlb_next,
 354         .stop           = tlb_stop,
 355         .show           = tlb_show,
 356 };
 357
 358 static int tlb_open(struct inode *inode, struct file *file)
 359 {
 360         return seq_open(file, &tlb_ops);
 361 }
 362
 363 static const struct file_operations proc_tlb_operations = {
 364         .open           = tlb_open,
 365         .read           = seq_read,
 366         .llseek         = seq_lseek,
 367         .release        = seq_release,
 368 };
 369
 370 static int __init proctlb_init(void)
 371 {
 372         struct proc_dir_entry *entry;
 373
 374         entry = create_proc_entry("tlb", 0, NULL);
 375         if (entry)
 376                 entry->proc_fops = &proc_tlb_operations;
 377         return 0;
 378 }
 379 late_initcall(proctlb_init);
 380 #endif /* CONFIG_PROC_FS */