arch/mips/mm/tlb-andes.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) 1997, 1998, 1999 Ralf Baechle (ralf@gnu.org)
   7  * Copyright (C) 1999 Silicon Graphics, Inc.
   8  * Copyright (C) 2000 Kanoj Sarcar (kanoj@sgi.com)
   9  */
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/mm.h>
  14 #include <asm/page.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/system.h>
  17 #include <asm/mmu_context.h>
  18
  19 extern void build_tlb_refill_handler(void);
  20
  21 #define NTLB_ENTRIES       64
  22 #define NTLB_ENTRIES_HALF  32
  23
  24 void local_flush_tlb_all(void)
  25 {
  26         unsigned long flags;
  27         unsigned long old_ctx;
  28         unsigned long entry;
  29
  30         local_irq_save(flags);
  31         /* Save old context and create impossible VPN2 value */
  32         old_ctx = read_c0_entryhi() & ASID_MASK;
  33         write_c0_entryhi(CKSEG0);
  34         write_c0_entrylo0(0);
  35         write_c0_entrylo1(0);
  36
  37         entry = read_c0_wired();
  38
  39         /* Blast 'em all away. */
  40         while (entry < NTLB_ENTRIES) {
  41                 write_c0_index(entry);
  42                 tlb_write_indexed();
  43                 entry++;
  44         }
  45         write_c0_entryhi(old_ctx);
  46         local_irq_restore(flags);
  47 }
  48
  49 void local_flush_tlb_mm(struct mm_struct *mm)
  50 {
  51         int cpu = smp_processor_id();
  52         if (cpu_context(cpu, mm) != 0) {
  53                 drop_mmu_context(mm,cpu);
  54         }
  55 }
  56
  57 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  58                            unsigned long end)
  59 {
  60         struct mm_struct *mm = vma->vm_mm;
  61         int cpu = smp_processor_id();
  62
  63         if (cpu_context(cpu, mm) != 0) {
  64                 unsigned long flags;
  65                 int size;
  66
  67                 local_irq_save(flags);
  68                 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  69                 size = (size + 1) >> 1;
  70                 if (size <= NTLB_ENTRIES_HALF) {
  71                         int oldpid = (read_c0_entryhi() & ASID_MASK);
  72                         int newpid = (cpu_context(smp_processor_id(), mm)
  73                                       & ASID_MASK);
  74
  75                         start &= (PAGE_MASK << 1);
  76                         end += ((PAGE_SIZE << 1) - 1);
  77                         end &= (PAGE_MASK << 1);
  78                         while(start < end) {
  79                                 int idx;
  80
  81                                 write_c0_entryhi(start | newpid);
  82                                 start += (PAGE_SIZE << 1);
  83                                 tlb_probe();
  84                                 idx = read_c0_index();
  85                                 write_c0_entrylo0(0);
  86                                 write_c0_entrylo1(0);
  87                                 write_c0_entryhi(CKSEG0);
  88                                 if(idx < 0)
  89                                         continue;
  90                                 tlb_write_indexed();
  91                         }
  92                         write_c0_entryhi(oldpid);
  93                 } else {
  94                         drop_mmu_context(mm, cpu);
  95                 }
  96                 local_irq_restore(flags);
  97         }
  98 }
  99
 100 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
 101 {
 102         unsigned long flags;
 103         int size;
 104
 105         size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 106         size = (size + 1) >> 1;
 107
 108         local_irq_save(flags);
 109         if (size <= NTLB_ENTRIES_HALF) {
 110                 int pid = read_c0_entryhi();
 111
 112                 start &= (PAGE_MASK << 1);
 113                 end += ((PAGE_SIZE << 1) - 1);
 114                 end &= (PAGE_MASK << 1);
 115
 116                 while (start < end) {
 117                         int idx;
 118
 119                         write_c0_entryhi(start);
 120                         start += (PAGE_SIZE << 1);
 121                         tlb_probe();
 122                         idx = read_c0_index();
 123                         write_c0_entrylo0(0);
 124                         write_c0_entrylo1(0);
 125                         write_c0_entryhi(CKSEG0 + (idx << (PAGE_SHIFT+1)));
 126                         if (idx < 0)
 127                                 continue;
 128                         tlb_write_indexed();
 129                 }
 130                 write_c0_entryhi(pid);
 131         } else {
 132                 local_flush_tlb_all();
 133         }
 134         local_irq_restore(flags);
 135 }
 136
 137 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 138 {
 139         if (cpu_context(smp_processor_id(), vma->vm_mm) != 0) {
 140                 unsigned long flags;
 141                 int oldpid, newpid, idx;
 142
 143                 newpid = (cpu_context(smp_processor_id(), vma->vm_mm) &
 144                           ASID_MASK);
 145                 page &= (PAGE_MASK << 1);
 146                 local_irq_save(flags);
 147                 oldpid = (read_c0_entryhi() & ASID_MASK);
 148                 write_c0_entryhi(page | newpid);
 149                 tlb_probe();
 150                 idx = read_c0_index();
 151                 write_c0_entrylo0(0);
 152                 write_c0_entrylo1(0);
 153                 write_c0_entryhi(CKSEG0);
 154                 if (idx < 0)
 155                         goto finish;
 156                 tlb_write_indexed();
 157
 158         finish:
 159                 write_c0_entryhi(oldpid);
 160                 local_irq_restore(flags);
 161         }
 162 }
 163
 164 /*
 165  * This one is only used for pages with the global bit set so we don't care
 166  * much about the ASID.
 167  */
 168 void local_flush_tlb_one(unsigned long page)
 169 {
 170         unsigned long flags;
 171         int oldpid, idx;
 172
 173         local_irq_save(flags);
 174         page &= (PAGE_MASK << 1);
 175         oldpid = read_c0_entryhi() & 0xff;
 176         write_c0_entryhi(page);
 177         tlb_probe();
 178         idx = read_c0_index();
 179         write_c0_entrylo0(0);
 180         write_c0_entrylo1(0);
 181         if (idx >= 0) {
 182                 /* Make sure all entries differ. */
 183                 write_c0_entryhi(CKSEG0+(idx<<(PAGE_SHIFT+1)));
 184                 tlb_write_indexed();
 185         }
 186         write_c0_entryhi(oldpid);
 187
 188         local_irq_restore(flags);
 189 }
 190
 191 /* XXX Simplify this.  On the R10000 writing a TLB entry for an virtual
 192    address that already exists will overwrite the old entry and not result
 193    in TLB malfunction or TLB shutdown.  */
 194 void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
 195 {
 196         unsigned long flags;
 197         pgd_t *pgdp;
 198         pmd_t *pmdp;
 199         pte_t *ptep;
 200         int idx, pid;
 201
 202         /*
 203          * Handle debugger faulting in for debugee.
 204          */
 205         if (current->active_mm != vma->vm_mm)
 206                 return;
 207
 208         pid = read_c0_entryhi() & ASID_MASK;
 209
 210         if ((pid != (cpu_context(smp_processor_id(), vma->vm_mm) & ASID_MASK))
 211             || (cpu_context(smp_processor_id(), vma->vm_mm) == 0)) {
 212                 printk(KERN_WARNING
 213                        "%s: Wheee, bogus tlbpid mmpid=%d tlbpid=%d\n",
 214                        __FUNCTION__, (int) (cpu_context(smp_processor_id(),
 215                        vma->vm_mm) & ASID_MASK), pid);
 216         }
 217
 218         local_irq_save(flags);
 219         address &= (PAGE_MASK << 1);
 220         write_c0_entryhi(address | (pid));
 221         pgdp = pgd_offset(vma->vm_mm, address);
 222         tlb_probe();
 223         pmdp = pmd_offset(pgdp, address);
 224         idx = read_c0_index();
 225         ptep = pte_offset_map(pmdp, address);
 226         write_c0_entrylo0(pte_val(*ptep++) >> 6);
 227         write_c0_entrylo1(pte_val(*ptep) >> 6);
 228         write_c0_entryhi(address | pid);
 229         if (idx < 0) {
 230                 tlb_write_random();
 231         } else {
 232                 tlb_write_indexed();
 233         }
 234         write_c0_entryhi(pid);
 235         local_irq_restore(flags);
 236 }
 237
 238 void __init tlb_init(void)
 239 {
 240         /*
 241          * You should never change this register:
 242          *   - On R4600 1.7 the tlbp never hits for pages smaller than
 243          *     the value in the c0_pagemask register.
 244          *   - The entire mm handling assumes the c0_pagemask register to
 245          *     be set for 4kb pages.
 246          */
 247         write_c0_pagemask(PM_4K);
 248         write_c0_wired(0);
 249         write_c0_framemask(0);
 250
 251         /* From this point on the ARC firmware is dead.  */
 252         local_flush_tlb_all();
 253
 254         /* Did I tell you that ARC SUCKS?  */
 255
 256         build_tlb_refill_handler();
 257 }