arch/mips/mm/tlb-r3k.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * r2300.c: R2000 and R3000 specific mmu/cache code.
   4  *
   5  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
   6  *
   7  * with a lot of changes to make this thing work for R3000s
   8  * Tx39XX R4k style caches added. HK
   9  * Copyright (C) 1998, 1999, 2000 Harald Koerfgen
  10  * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
  11  * Copyright (C) 2002  Ralf Baechle
  12  * Copyright (C) 2002  Maciej W. Rozycki
  13  */
  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/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 /* TLB operations. */
  40 static void local_flush_tlb_from(int entry)
  41 {
  42         unsigned long old_ctx;
  43
  44         old_ctx = read_c0_entryhi() & cpu_asid_mask(&current_cpu_data);
  45         write_c0_entrylo0(0);
  46         while (entry < current_cpu_data.tlbsize) {
  47                 write_c0_index(entry << 8);
  48                 write_c0_entryhi((entry | 0x80000) << 12);
  49                 entry++;                                /* BARRIER */
  50                 tlb_write_indexed();
  51         }
  52         write_c0_entryhi(old_ctx);
  53 }
  54
  55 void local_flush_tlb_all(void)
  56 {
  57         unsigned long flags;
  58
  59 #ifdef DEBUG_TLB
  60         printk("[tlball]");
  61 #endif
  62         local_irq_save(flags);
  63         local_flush_tlb_from(8);
  64         local_irq_restore(flags);
  65 }
  66
  67 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  68                            unsigned long end)
  69 {
  70         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
  71         struct mm_struct *mm = vma->vm_mm;
  72         int cpu = smp_processor_id();
  73
  74         if (cpu_context(cpu, mm) != 0) {
  75                 unsigned long size, flags;
  76
  77 #ifdef DEBUG_TLB
  78                 printk("[tlbrange<%lu,0x%08lx,0x%08lx>]",
  79                         cpu_context(cpu, mm) & asid_mask, start, end);
  80 #endif
  81                 local_irq_save(flags);
  82                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  83                 if (size <= current_cpu_data.tlbsize) {
  84                         int oldpid = read_c0_entryhi() & asid_mask;
  85                         int newpid = cpu_context(cpu, mm) & asid_mask;
  86
  87                         start &= PAGE_MASK;
  88                         end += PAGE_SIZE - 1;
  89                         end &= PAGE_MASK;
  90                         while (start < end) {
  91                                 int idx;
  92
  93                                 write_c0_entryhi(start | newpid);
  94                                 start += PAGE_SIZE;     /* BARRIER */
  95                                 tlb_probe();
  96                                 idx = read_c0_index();
  97                                 write_c0_entrylo0(0);
  98                                 write_c0_entryhi(KSEG0);
  99                                 if (idx < 0)            /* BARRIER */
 100                                         continue;
 101                                 tlb_write_indexed();
 102                         }
 103                         write_c0_entryhi(oldpid);
 104                 } else {
 105                         drop_mmu_context(mm);
 106                 }
 107                 local_irq_restore(flags);
 108         }
 109 }
 110
 111 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 112 {
 113         unsigned long size, flags;
 114
 115 #ifdef DEBUG_TLB
 116         printk("[tlbrange<%lu,0x%08lx,0x%08lx>]", start, end);
 117 #endif
 118         local_irq_save(flags);
 119         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 120         if (size <= current_cpu_data.tlbsize) {
 121                 int pid = read_c0_entryhi();
 122
 123                 start &= PAGE_MASK;
 124                 end += PAGE_SIZE - 1;
 125                 end &= PAGE_MASK;
 126
 127                 while (start < end) {
 128                         int idx;
 129
 130                         write_c0_entryhi(start);
 131                         start += PAGE_SIZE;             /* BARRIER */
 132                         tlb_probe();
 133                         idx = read_c0_index();
 134                         write_c0_entrylo0(0);
 135                         write_c0_entryhi(KSEG0);
 136                         if (idx < 0)                    /* BARRIER */
 137                                 continue;
 138                         tlb_write_indexed();
 139                 }
 140                 write_c0_entryhi(pid);
 141         } else {
 142                 local_flush_tlb_all();
 143         }
 144         local_irq_restore(flags);
 145 }
 146
 147 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 148 {
 149         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
 150         int cpu = smp_processor_id();
 151
 152         if (cpu_context(cpu, vma->vm_mm) != 0) {
 153                 unsigned long flags;
 154                 int oldpid, newpid, idx;
 155
 156 #ifdef DEBUG_TLB
 157                 printk("[tlbpage<%lu,0x%08lx>]", cpu_context(cpu, vma->vm_mm), page);
 158 #endif
 159                 newpid = cpu_context(cpu, vma->vm_mm) & asid_mask;
 160                 page &= PAGE_MASK;
 161                 local_irq_save(flags);
 162                 oldpid = read_c0_entryhi() & asid_mask;
 163                 write_c0_entryhi(page | newpid);
 164                 BARRIER;
 165                 tlb_probe();
 166                 idx = read_c0_index();
 167                 write_c0_entrylo0(0);
 168                 write_c0_entryhi(KSEG0);
 169                 if (idx < 0)                            /* BARRIER */
 170                         goto finish;
 171                 tlb_write_indexed();
 172
 173 finish:
 174                 write_c0_entryhi(oldpid);
 175                 local_irq_restore(flags);
 176         }
 177 }
 178
 179 void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
 180 {
 181         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
 182         unsigned long flags;
 183         int idx, pid;
 184
 185         /*
 186          * Handle debugger faulting in for debugee.
 187          */
 188         if (current->active_mm != vma->vm_mm)
 189                 return;
 190
 191         pid = read_c0_entryhi() & asid_mask;
 192
 193 #ifdef DEBUG_TLB
 194         if ((pid != (cpu_context(cpu, vma->vm_mm) & asid_mask)) || (cpu_context(cpu, vma->vm_mm) == 0)) {
 195                 printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%lu tlbpid=%d\n",
 196                        (cpu_context(cpu, vma->vm_mm)), pid);
 197         }
 198 #endif
 199
 200         local_irq_save(flags);
 201         address &= PAGE_MASK;
 202         write_c0_entryhi(address | pid);
 203         BARRIER;
 204         tlb_probe();
 205         idx = read_c0_index();
 206         write_c0_entrylo0(pte_val(pte));
 207         write_c0_entryhi(address | pid);
 208         if (idx < 0) {                                  /* BARRIER */
 209                 tlb_write_random();
 210         } else {
 211                 tlb_write_indexed();
 212         }
 213         write_c0_entryhi(pid);
 214         local_irq_restore(flags);
 215 }
 216
 217 void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
 218                      unsigned long entryhi, unsigned long pagemask)
 219 {
 220         unsigned long asid_mask = cpu_asid_mask(&current_cpu_data);
 221         unsigned long flags;
 222         unsigned long old_ctx;
 223         static unsigned long wired = 0;
 224
 225         if (wired < 8) {
 226 #ifdef DEBUG_TLB
 227                 printk("[tlbwired<entry lo0 %8x, hi %8x\n>]\n",
 228                        entrylo0, entryhi);
 229 #endif
 230
 231                 local_irq_save(flags);
 232                 old_ctx = read_c0_entryhi() & asid_mask;
 233                 write_c0_entrylo0(entrylo0);
 234                 write_c0_entryhi(entryhi);
 235                 write_c0_index(wired);
 236                 wired++;                                /* BARRIER */
 237                 tlb_write_indexed();
 238                 write_c0_entryhi(old_ctx);
 239                 local_flush_tlb_all();
 240                 local_irq_restore(flags);
 241         }
 242 }
 243
 244 void tlb_init(void)
 245 {
 246         local_flush_tlb_from(0);
 247         build_tlb_refill_handler();
 248 }