arch/mips/mm/tlb-r8k.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
   7  * Copyright (C) 1997, 1998, 1999, 2000 Ralf Baechle ralf@gnu.org
   8  * Carsten Langgaard, carstenl@mips.com
   9  * Copyright (C) 2002 MIPS Technologies, Inc.  All rights reserved.
  10  */
  11 #include <linux/sched.h>
  12 #include <linux/smp.h>
  13 #include <linux/mm.h>
  14
  15 #include <asm/cpu.h>
  16 #include <asm/bootinfo.h>
  17 #include <asm/mmu_context.h>
  18 #include <asm/pgtable.h>
  19
  20 extern void build_tlb_refill_handler(void);
  21
  22 #define TFP_TLB_SIZE            384
  23 #define TFP_TLB_SET_SHIFT       7
  24
  25 /* CP0 hazard avoidance. */
  26 #define BARRIER __asm__ __volatile__(".set noreorder\n\t" \
  27                                      "nop; nop; nop; nop; nop; nop;\n\t" \
  28                                      ".set reorder\n\t")
  29
  30 void local_flush_tlb_all(void)
  31 {
  32         unsigned long flags;
  33         unsigned long old_ctx;
  34         int entry;
  35
  36         local_irq_save(flags);
  37         /* Save old context and create impossible VPN2 value */
  38         old_ctx = read_c0_entryhi();
  39         write_c0_entrylo(0);
  40
  41         for (entry = 0; entry < TFP_TLB_SIZE; entry++) {
  42                 write_c0_tlbset(entry >> TFP_TLB_SET_SHIFT);
  43                 write_c0_vaddr(entry << PAGE_SHIFT);
  44                 write_c0_entryhi(CKSEG0 + (entry << (PAGE_SHIFT + 1)));
  45                 mtc0_tlbw_hazard();
  46                 tlb_write();
  47         }
  48         tlbw_use_hazard();
  49         write_c0_entryhi(old_ctx);
  50         local_irq_restore(flags);
  51 }
  52
  53 void local_flush_tlb_mm(struct mm_struct *mm)
  54 {
  55         int cpu = smp_processor_id();
  56
  57         if (cpu_context(cpu, mm) != 0)
  58                 drop_mmu_context(mm, cpu);
  59 }
  60
  61 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  62         unsigned long end)
  63 {
  64         struct mm_struct *mm = vma->vm_mm;
  65         int cpu = smp_processor_id();
  66         unsigned long flags;
  67         int oldpid, newpid, size;
  68
  69         if (!cpu_context(cpu, mm))
  70                 return;
  71
  72         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  73         size = (size + 1) >> 1;
  74
  75         local_irq_save(flags);
  76
  77         if (size > TFP_TLB_SIZE / 2) {
  78                 drop_mmu_context(mm, cpu);
  79                 goto out_restore;
  80         }
  81
  82         oldpid = read_c0_entryhi();
  83         newpid = cpu_asid(cpu, mm);
  84
  85         write_c0_entrylo(0);
  86
  87         start &= PAGE_MASK;
  88         end += (PAGE_SIZE - 1);
  89         end &= PAGE_MASK;
  90         while (start < end) {
  91                 signed long idx;
  92
  93                 write_c0_vaddr(start);
  94                 write_c0_entryhi(start);
  95                 start += PAGE_SIZE;
  96                 tlb_probe();
  97                 idx = read_c0_tlbset();
  98                 if (idx < 0)
  99                         continue;
 100
 101                 write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
 102                 tlb_write();
 103         }
 104         write_c0_entryhi(oldpid);
 105
 106 out_restore:
 107         local_irq_restore(flags);
 108 }
 109
 110 /* Usable for KV1 addresses only! */
 111 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 112 {
 113         unsigned long size, flags;
 114
 115         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 116         size = (size + 1) >> 1;
 117
 118         if (size > TFP_TLB_SIZE / 2) {
 119                 local_flush_tlb_all();
 120                 return;
 121         }
 122
 123         local_irq_save(flags);
 124
 125         write_c0_entrylo(0);
 126
 127         start &= PAGE_MASK;
 128         end += (PAGE_SIZE - 1);
 129         end &= PAGE_MASK;
 130         while (start < end) {
 131                 signed long idx;
 132
 133                 write_c0_vaddr(start);
 134                 write_c0_entryhi(start);
 135                 start += PAGE_SIZE;
 136                 tlb_probe();
 137                 idx = read_c0_tlbset();
 138                 if (idx < 0)
 139                         continue;
 140
 141                 write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
 142                 tlb_write();
 143         }
 144
 145         local_irq_restore(flags);
 146 }
 147
 148 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 149 {
 150         int cpu = smp_processor_id();
 151         unsigned long flags;
 152         int oldpid, newpid;
 153         signed long idx;
 154
 155         if (!cpu_context(cpu, vma->vm_mm))
 156                 return;
 157
 158         newpid = cpu_asid(cpu, vma->vm_mm);
 159         page &= PAGE_MASK;
 160         local_irq_save(flags);
 161         oldpid = read_c0_entryhi();
 162         write_c0_vaddr(page);
 163         write_c0_entryhi(newpid);
 164         tlb_probe();
 165         idx = read_c0_tlbset();
 166         if (idx < 0)
 167                 goto finish;
 168
 169         write_c0_entrylo(0);
 170         write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
 171         tlb_write();
 172
 173 finish:
 174         write_c0_entryhi(oldpid);
 175         local_irq_restore(flags);
 176 }
 177
 178 /*
 179  * We will need multiple versions of update_mmu_cache(), one that just
 180  * updates the TLB with the new pte(s), and another which also checks
 181  * for the R4k "end of page" hardware bug and does the needy.
 182  */
 183 void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 184 {
 185         unsigned long flags;
 186         pgd_t *pgdp;
 187         pmd_t *pmdp;
 188         pte_t *ptep;
 189         int pid;
 190
 191         /*
 192          * Handle debugger faulting in for debugee.
 193          */
 194         if (current->active_mm != vma->vm_mm)
 195                 return;
 196
 197         pid = read_c0_entryhi() & ASID_MASK;
 198
 199         local_irq_save(flags);
 200         address &= PAGE_MASK;
 201         write_c0_vaddr(address);
 202         write_c0_entryhi(pid);
 203         pgdp = pgd_offset(vma->vm_mm, address);
 204         pmdp = pmd_offset(pgdp, address);
 205         ptep = pte_offset_map(pmdp, address);
 206         tlb_probe();
 207
 208         write_c0_entrylo(pte_val(*ptep++) >> 6);
 209         tlb_write();
 210
 211         write_c0_entryhi(pid);
 212         local_irq_restore(flags);
 213 }
 214
 215 static void probe_tlb(unsigned long config)
 216 {
 217         struct cpuinfo_mips *c = &current_cpu_data;
 218
 219         c->tlbsize = 3 * 128;           /* 3 sets each 128 entries */
 220 }
 221
 222 void tlb_init(void)
 223 {
 224         unsigned int config = read_c0_config();
 225         unsigned long status;
 226
 227         probe_tlb(config);
 228
 229         status = read_c0_status();
 230         status &= ~(ST0_UPS | ST0_KPS);
 231 #ifdef CONFIG_PAGE_SIZE_4KB
 232         status |= (TFP_PAGESIZE_4K << 32) | (TFP_PAGESIZE_4K << 36);
 233 #elif defined(CONFIG_PAGE_SIZE_8KB)
 234         status |= (TFP_PAGESIZE_8K << 32) | (TFP_PAGESIZE_8K << 36);
 235 #elif defined(CONFIG_PAGE_SIZE_16KB)
 236         status |= (TFP_PAGESIZE_16K << 32) | (TFP_PAGESIZE_16K << 36);
 237 #elif defined(CONFIG_PAGE_SIZE_64KB)
 238         status |= (TFP_PAGESIZE_64K << 32) | (TFP_PAGESIZE_64K << 36);
 239 #endif
 240         write_c0_status(status);
 241
 242         write_c0_wired(0);
 243
 244         local_flush_tlb_all();
 245
 246         build_tlb_refill_handler();
 247 }