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 static void local_flush_tlb_from(int entry)
  43 {
  44         unsigned long old_ctx;
  45
  46         old_ctx = read_c0_entryhi() & cpu_asid_mask(&current_cpu_data);
  47         write_c0_entrylo0(0);
  48         while (entry < current_cpu_data.tlbsize) {
  49                 write_c0_index(entry << 8);
  50                 write_c0_entryhi((entry | 0x80000) << 12);
  51                 entry++;                                /* BARRIER */
  52                 tlb_write_indexed();
  53         }
  54         write_c0_entryhi(old_ctx);
  55 }
  56
  57 void local_flush_tlb_all(void)
  58 {
  59         unsigned long flags;
  60
  61 #ifdef DEBUG_TLB
  62         printk("[tlball]");
  63 #endif
  64         local_irq_save(flags);
  65         local_flush_tlb_from(r3k_have_wired_reg ? read_c0_wired() : 8);
  66         local_irq_restore(flags);
  67 }
  68
  69 void local_flush_tlb_mm(struct mm_struct *mm)
  70 {
  71         int cpu = smp_processor_id();
  72
  73         if (cpu_context(cpu, mm) != 0) {
  74 #ifdef DEBUG_TLB
  75                 printk("[tlbmm<%lu>]", (unsigned long)cpu_context(cpu, mm));
  76 #endif
  77                 drop_mmu_context(mm, cpu);
  78         }
  79 }
  80
  81 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  82                            unsigned long end)
  83 {
  84         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
  85         struct mm_struct *mm = vma->vm_mm;
  86         int cpu = smp_processor_id();
  87
  88         if (cpu_context(cpu, mm) != 0) {
  89                 unsigned long size, flags;
  90
  91 #ifdef DEBUG_TLB
  92                 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
  93                         cpu_context(cpu, mm) & asid_mask, start, end);
  94 #endif
  95                 local_irq_save(flags);
  96                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  97                 if (size <= current_cpu_data.tlbsize) {
  98                         int oldpid = read_c0_entryhi() & asid_mask;
  99                         int newpid = cpu_context(cpu, mm) & asid_mask;
 100
 101                         start &= PAGE_MASK;
 102                         end += PAGE_SIZE - 1;
 103                         end &= PAGE_MASK;
 104                         while (start < end) {
 105                                 int idx;
 106
 107                                 write_c0_entryhi(start | newpid);
 108                                 start += PAGE_SIZE;     /* BARRIER */
 109                                 tlb_probe();
 110                                 idx = read_c0_index();
 111                                 write_c0_entrylo0(0);
 112                                 write_c0_entryhi(KSEG0);
 113                                 if (idx < 0)            /* BARRIER */
 114                                         continue;
 115                                 tlb_write_indexed();
 116                         }
 117                         write_c0_entryhi(oldpid);
 118                 } else {
 119                         drop_mmu_context(mm, cpu);
 120                 }
 121                 local_irq_restore(flags);
 122         }
 123 }
 124
 125 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 126 {
 127         unsigned long size, flags;
 128
 129 #ifdef DEBUG_TLB
 130         printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
 131 #endif
 132         local_irq_save(flags);
 133         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 134         if (size <= current_cpu_data.tlbsize) {
 135                 int pid = read_c0_entryhi();
 136
 137                 start &= PAGE_MASK;
 138                 end += PAGE_SIZE - 1;
 139                 end &= PAGE_MASK;
 140
 141                 while (start < end) {
 142                         int idx;
 143
 144                         write_c0_entryhi(start);
 145                         start += PAGE_SIZE;             /* BARRIER */
 146                         tlb_probe();
 147                         idx = read_c0_index();
 148                         write_c0_entrylo0(0);
 149                         write_c0_entryhi(KSEG0);
 150                         if (idx < 0)                    /* BARRIER */
 151                                 continue;
 152                         tlb_write_indexed();
 153                 }
 154                 write_c0_entryhi(pid);
 155         } else {
 156                 local_flush_tlb_all();
 157         }
 158         local_irq_restore(flags);
 159 }
 160
 161 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 162 {
 163         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
 164         int cpu = smp_processor_id();
 165
 166         if (cpu_context(cpu, vma->vm_mm) != 0) {
 167                 unsigned long flags;
 168                 int oldpid, newpid, idx;
 169
 170 #ifdef DEBUG_TLB
 171                 printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
 172 #endif
 173                 newpid = cpu_context(cpu, vma->vm_mm) & asid_mask;
 174                 page &= PAGE_MASK;
 175                 local_irq_save(flags);
 176                 oldpid = read_c0_entryhi() & asid_mask;
 177                 write_c0_entryhi(page | newpid);
 178                 BARRIER;
 179                 tlb_probe();
 180                 idx = read_c0_index();
 181                 write_c0_entrylo0(0);
 182                 write_c0_entryhi(KSEG0);
 183                 if (idx < 0)                            /* BARRIER */
 184                         goto finish;
 185                 tlb_write_indexed();
 186
 187 finish:
 188                 write_c0_entryhi(oldpid);
 189                 local_irq_restore(flags);
 190         }
 191 }
 192
 193 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 194 {
 195         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
 196         unsigned long flags;
 197         int idx, pid;
 198
 199         /*
 200          * Handle debugger faulting in for debugee.
 201          */
 202         if (current->active_mm != vma->vm_mm)
 203                 return;
 204
 205         pid = read_c0_entryhi() & asid_mask;
 206
 207 #ifdef DEBUG_TLB
 208         if ((pid != (cpu_context(cpu, vma->vm_mm) & asid_mask)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
 209                 printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
 210                        (cpu_context(cpu, vma->vm_mm)), pid);
 211         }
 212 #endif
 213
 214         local_irq_save(flags);
 215         address &= PAGE_MASK;
 216         write_c0_entryhi(address | pid);
 217         BARRIER;
 218         tlb_probe();
 219         idx = read_c0_index();
 220         write_c0_entrylo0(pte_val(pte));
 221         write_c0_entryhi(address | pid);
 222         if (idx < 0) {                                  /* BARRIER */
 223                 tlb_write_random();
 224         } else {
 225                 tlb_write_indexed();
 226         }
 227         write_c0_entryhi(pid);
 228         local_irq_restore(flags);
 229 }
 230
 231 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 232                      unsigned long entryhi, unsigned long pagemask)
 233 {
 234         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
 235         unsigned long flags;
 236         unsigned long old_ctx;
 237         static unsigned long wired = 0;
 238
 239         if (r3k_have_wired_reg) {                       /* TX39XX */
 240                 unsigned long old_pagemask;
 241                 unsigned long w;
 242
 243 #ifdef DEBUG_TLB
 244                 printk("[tlbwired<entry lo0 %8x, hi %8x\n, pagemask %8x>]\n",
 245                        entrylo0, entryhi, pagemask);
 246 #endif
 247
 248                 local_irq_save(flags);
 249                 /* Save old context and create impossible VPN2 value */
 250                 old_ctx = read_c0_entryhi() & asid_mask;
 251                 old_pagemask = read_c0_pagemask();
 252                 w = read_c0_wired();
 253                 write_c0_wired(w + 1);
 254                 write_c0_index(w << 8);
 255                 write_c0_pagemask(pagemask);
 256                 write_c0_entryhi(entryhi);
 257                 write_c0_entrylo0(entrylo0);
 258                 BARRIER;
 259                 tlb_write_indexed();
 260
 261                 write_c0_entryhi(old_ctx);
 262                 write_c0_pagemask(old_pagemask);
 263                 local_flush_tlb_all();
 264                 local_irq_restore(flags);
 265
 266         } else if (wired < 8) {
 267 #ifdef DEBUG_TLB
 268                 printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
 269                        entrylo0, entryhi);
 270 #endif
 271
 272                 local_irq_save(flags);
 273                 old_ctx = read_c0_entryhi() & asid_mask;
 274                 write_c0_entrylo0(entrylo0);
 275                 write_c0_entryhi(entryhi);
 276                 write_c0_index(wired);
 277                 wired++;                                /* BARRIER */
 278                 tlb_write_indexed();
 279                 write_c0_entryhi(old_ctx);
 280                 local_flush_tlb_all();
 281                 local_irq_restore(flags);
 282         }
 283 }
 284
 285 void tlb_init(void)
 286 {
 287         switch (current_cpu_type()) {
 288         case CPU_TX3922:
 289         case CPU_TX3927:
 290                 r3k_have_wired_reg = 1;
 291                 write_c0_wired(0);              /* Set to 8 on reset... */
 292                 break;
 293         }
 294         local_flush_tlb_from(0);
 295         build_tlb_refill_handler();
 296 }