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   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 (dm@engr.sgi.com)
   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/init.h>
  12 #include <linux/sched.h>
  13 #include <linux/smp.h>
  14 #include <linux/mm.h>
  15
  16 #include <asm/cpu.h>
  17 #include <asm/bootinfo.h>
  18 #include <asm/mmu_context.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/system.h>
  21
  22 extern void build_tlb_refill_handler(void);
  23
  24 #define TFP_TLB_SIZE            384
  25 #define TFP_TLB_SET_SHIFT       7
  26
  27 /* CP0 hazard avoidance. */
  28 #define BARRIER __asm__ __volatile__(".set noreorder\n\t" \
  29                                      "nop; nop; nop; nop; nop; nop;\n\t" \
  30                                      ".set reorder\n\t")
  31
  32 void local_flush_tlb_all(void)
  33 {
  34         unsigned long flags;
  35         unsigned long old_ctx;
  36         int entry;
  37
  38         local_irq_save(flags);
  39         /* Save old context and create impossible VPN2 value */
  40         old_ctx = read_c0_entryhi();
  41         write_c0_entrylo(0);
  42
  43         for (entry = 0; entry < TFP_TLB_SIZE; entry++) {
  44                 write_c0_tlbset(entry >> TFP_TLB_SET_SHIFT);
  45                 write_c0_vaddr(entry << PAGE_SHIFT);
  46                 write_c0_entryhi(CKSEG0 + (entry << (PAGE_SHIFT + 1)));
  47                 mtc0_tlbw_hazard();
  48                 tlb_write();
  49         }
  50         tlbw_use_hazard();
  51         write_c0_entryhi(old_ctx);
  52         local_irq_restore(flags);
  53 }
  54
  55 void local_flush_tlb_mm(struct mm_struct *mm)
  56 {
  57         int cpu = smp_processor_id();
  58
  59         if (cpu_context(cpu, mm) != 0)
  60                 drop_mmu_context(mm, cpu);
  61 }
  62
  63 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  64         unsigned long end)
  65 {
  66         struct mm_struct *mm = vma->vm_mm;
  67         int cpu = smp_processor_id();
  68         unsigned long flags;
  69         int oldpid, newpid, size;
  70
  71         if (!cpu_context(cpu, mm))
  72                 return;
  73
  74         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  75         size = (size + 1) >> 1;
  76
  77         local_irq_save(flags);
  78
  79         if (size > TFP_TLB_SIZE / 2) {
  80                 drop_mmu_context(mm, cpu);
  81                 goto out_restore;
  82         }
  83
  84         oldpid = read_c0_entryhi();
  85         newpid = cpu_asid(cpu, mm);
  86
  87         write_c0_entrylo(0);
  88
  89         start &= PAGE_MASK;
  90         end += (PAGE_SIZE - 1);
  91         end &= PAGE_MASK;
  92         while (start < end) {
  93                 signed long idx;
  94
  95                 write_c0_vaddr(start);
  96                 write_c0_entryhi(start);
  97                 start += PAGE_SIZE;
  98                 tlb_probe();
  99                 idx = read_c0_tlbset();
 100                 if (idx < 0)
 101                         continue;
 102
 103                 write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
 104                 tlb_write();
 105         }
 106         write_c0_entryhi(oldpid);
 107
 108 out_restore:
 109         local_irq_restore(flags);
 110 }
 111
 112 /* Usable for KV1 addresses only! */
 113 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 114 {
 115         unsigned long size, flags;
 116
 117         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 118         size = (size + 1) >> 1;
 119
 120         if (size > TFP_TLB_SIZE / 2) {
 121                 local_flush_tlb_all();
 122                 return;
 123         }
 124
 125         local_irq_save(flags);
 126
 127         write_c0_entrylo(0);
 128
 129         start &= PAGE_MASK;
 130         end += (PAGE_SIZE - 1);
 131         end &= PAGE_MASK;
 132         while (start < end) {
 133                 signed long idx;
 134
 135                 write_c0_vaddr(start);
 136                 write_c0_entryhi(start);
 137                 start += PAGE_SIZE;
 138                 tlb_probe();
 139                 idx = read_c0_tlbset();
 140                 if (idx < 0)
 141                         continue;
 142
 143                 write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
 144                 tlb_write();
 145         }
 146
 147         local_irq_restore(flags);
 148 }
 149
 150 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 151 {
 152         int cpu = smp_processor_id();
 153         unsigned long flags;
 154         int oldpid, newpid;
 155         signed long idx;
 156
 157         if (!cpu_context(cpu, vma->vm_mm))
 158                 return;
 159
 160         newpid = cpu_asid(cpu, vma->vm_mm);
 161         page &= PAGE_MASK;
 162         local_irq_save(flags);
 163         oldpid = read_c0_entryhi();
 164         write_c0_vaddr(page);
 165         write_c0_entryhi(newpid);
 166         tlb_probe();
 167         idx = read_c0_tlbset();
 168         if (idx < 0)
 169                 goto finish;
 170
 171         write_c0_entrylo(0);
 172         write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT + 1)));
 173         tlb_write();
 174
 175 finish:
 176         write_c0_entryhi(oldpid);
 177         local_irq_restore(flags);
 178 }
 179
 180 /*
 181  * We will need multiple versions of update_mmu_cache(), one that just
 182  * updates the TLB with the new pte(s), and another which also checks
 183  * for the R4k "end of page" hardware bug and does the needy.
 184  */
 185 void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 186 {
 187         unsigned long flags;
 188         pgd_t *pgdp;
 189         pmd_t *pmdp;
 190         pte_t *ptep;
 191         int pid;
 192
 193         /*
 194          * Handle debugger faulting in for debugee.
 195          */
 196         if (current->active_mm != vma->vm_mm)
 197                 return;
 198
 199         pid = read_c0_entryhi() & ASID_MASK;
 200
 201         local_irq_save(flags);
 202         address &= PAGE_MASK;
 203         write_c0_vaddr(address);
 204         write_c0_entryhi(pid);
 205         pgdp = pgd_offset(vma->vm_mm, address);
 206         pmdp = pmd_offset(pgdp, address);
 207         ptep = pte_offset_map(pmdp, address);
 208         tlb_probe();
 209
 210         write_c0_entrylo(pte_val(*ptep++) >> 6);
 211         tlb_write();
 212
 213         write_c0_entryhi(pid);
 214         local_irq_restore(flags);
 215 }
 216
 217 static void __cpuinit probe_tlb(unsigned long config)
 218 {
 219         struct cpuinfo_mips *c = &current_cpu_data;
 220
 221         c->tlbsize = 3 * 128;           /* 3 sets each 128 entries */
 222 }
 223
 224 void __cpuinit tlb_init(void)
 225 {
 226         unsigned int config = read_c0_config();
 227         unsigned long status;
 228
 229         probe_tlb(config);
 230
 231         status = read_c0_status();
 232         status &= ~(ST0_UPS | ST0_KPS);
 233 #ifdef CONFIG_PAGE_SIZE_4KB
 234         status |= (TFP_PAGESIZE_4K << 32) | (TFP_PAGESIZE_4K << 36);
 235 #elif defined(CONFIG_PAGE_SIZE_8KB)
 236         status |= (TFP_PAGESIZE_8K << 32) | (TFP_PAGESIZE_8K << 36);
 237 #elif defined(CONFIG_PAGE_SIZE_16KB)
 238         status |= (TFP_PAGESIZE_16K << 32) | (TFP_PAGESIZE_16K << 36);
 239 #elif defined(CONFIG_PAGE_SIZE_64KB)
 240         status |= (TFP_PAGESIZE_64K << 32) | (TFP_PAGESIZE_64K << 36);
 241 #endif
 242         write_c0_status(status);
 243
 244         write_c0_wired(0);
 245
 246         local_flush_tlb_all();
 247
 248         build_tlb_refill_handler();
 249 }