arch/mips/mm/c-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) 2001, 2004, 2007  Maciej W. Rozycki
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/smp.h>
  15 #include <linux/mm.h>
  16
  17 #include <asm/page.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/mmu_context.h>
  20 #include <asm/isadep.h>
  21 #include <asm/io.h>
  22 #include <asm/bootinfo.h>
  23 #include <asm/cpu.h>
  24
  25 static unsigned long icache_size, dcache_size;          /* Size in bytes */
  26 static unsigned long icache_lsize, dcache_lsize;        /* Size in bytes */
  27
  28 unsigned long r3k_cache_size(unsigned long ca_flags)
  29 {
  30         unsigned long flags, status, dummy, size;
  31         volatile unsigned long *p;
  32
  33         p = (volatile unsigned long *) KSEG0;
  34
  35         flags = read_c0_status();
  36
  37         /* isolate cache space */
  38         write_c0_status((ca_flags|flags)&~ST0_IEC);
  39
  40         *p = 0xa5a55a5a;
  41         dummy = *p;
  42         status = read_c0_status();
  43
  44         if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
  45                 size = 0;
  46         } else {
  47                 for (size = 128; size <= 0x40000; size <<= 1)
  48                         *(p + size) = 0;
  49                 *p = -1;
  50                 for (size = 128;
  51                      (size <= 0x40000) && (*(p + size) == 0);
  52                      size <<= 1)
  53                         ;
  54                 if (size > 0x40000)
  55                         size = 0;
  56         }
  57
  58         write_c0_status(flags);
  59
  60         return size * sizeof(*p);
  61 }
  62
  63 unsigned long r3k_cache_lsize(unsigned long ca_flags)
  64 {
  65         unsigned long flags, status, lsize, i;
  66         volatile unsigned long *p;
  67
  68         p = (volatile unsigned long *) KSEG0;
  69
  70         flags = read_c0_status();
  71
  72         /* isolate cache space */
  73         write_c0_status((ca_flags|flags)&~ST0_IEC);
  74
  75         for (i = 0; i < 128; i++)
  76                 *(p + i) = 0;
  77         *(volatile unsigned char *)p = 0;
  78         for (lsize = 1; lsize < 128; lsize <<= 1) {
  79                 *(p + lsize);
  80                 status = read_c0_status();
  81                 if (!(status & ST0_CM))
  82                         break;
  83         }
  84         for (i = 0; i < 128; i += lsize)
  85                 *(volatile unsigned char *)(p + i) = 0;
  86
  87         write_c0_status(flags);
  88
  89         return lsize * sizeof(*p);
  90 }
  91
  92 static void r3k_probe_cache(void)
  93 {
  94         dcache_size = r3k_cache_size(ST0_ISC);
  95         if (dcache_size)
  96                 dcache_lsize = r3k_cache_lsize(ST0_ISC);
  97
  98         icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
  99         if (icache_size)
 100                 icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
 101 }
 102
 103 static void r3k_flush_icache_range(unsigned long start, unsigned long end)
 104 {
 105         unsigned long size, i, flags;
 106         volatile unsigned char *p;
 107
 108         size = end - start;
 109         if (size > icache_size || KSEGX(start) != KSEG0) {
 110                 start = KSEG0;
 111                 size = icache_size;
 112         }
 113         p = (char *)start;
 114
 115         flags = read_c0_status();
 116
 117         /* isolate cache space */
 118         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
 119
 120         for (i = 0; i < size; i += 0x080) {
 121                 asm(    "sb\t$0, 0x000(%0)\n\t"
 122                         "sb\t$0, 0x004(%0)\n\t"
 123                         "sb\t$0, 0x008(%0)\n\t"
 124                         "sb\t$0, 0x00c(%0)\n\t"
 125                         "sb\t$0, 0x010(%0)\n\t"
 126                         "sb\t$0, 0x014(%0)\n\t"
 127                         "sb\t$0, 0x018(%0)\n\t"
 128                         "sb\t$0, 0x01c(%0)\n\t"
 129                         "sb\t$0, 0x020(%0)\n\t"
 130                         "sb\t$0, 0x024(%0)\n\t"
 131                         "sb\t$0, 0x028(%0)\n\t"
 132                         "sb\t$0, 0x02c(%0)\n\t"
 133                         "sb\t$0, 0x030(%0)\n\t"
 134                         "sb\t$0, 0x034(%0)\n\t"
 135                         "sb\t$0, 0x038(%0)\n\t"
 136                         "sb\t$0, 0x03c(%0)\n\t"
 137                         "sb\t$0, 0x040(%0)\n\t"
 138                         "sb\t$0, 0x044(%0)\n\t"
 139                         "sb\t$0, 0x048(%0)\n\t"
 140                         "sb\t$0, 0x04c(%0)\n\t"
 141                         "sb\t$0, 0x050(%0)\n\t"
 142                         "sb\t$0, 0x054(%0)\n\t"
 143                         "sb\t$0, 0x058(%0)\n\t"
 144                         "sb\t$0, 0x05c(%0)\n\t"
 145                         "sb\t$0, 0x060(%0)\n\t"
 146                         "sb\t$0, 0x064(%0)\n\t"
 147                         "sb\t$0, 0x068(%0)\n\t"
 148                         "sb\t$0, 0x06c(%0)\n\t"
 149                         "sb\t$0, 0x070(%0)\n\t"
 150                         "sb\t$0, 0x074(%0)\n\t"
 151                         "sb\t$0, 0x078(%0)\n\t"
 152                         "sb\t$0, 0x07c(%0)\n\t"
 153                         : : "r" (p) );
 154                 p += 0x080;
 155         }
 156
 157         write_c0_status(flags);
 158 }
 159
 160 static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
 161 {
 162         unsigned long size, i, flags;
 163         volatile unsigned char *p;
 164
 165         size = end - start;
 166         if (size > dcache_size || KSEGX(start) != KSEG0) {
 167                 start = KSEG0;
 168                 size = dcache_size;
 169         }
 170         p = (char *)start;
 171
 172         flags = read_c0_status();
 173
 174         /* isolate cache space */
 175         write_c0_status((ST0_ISC|flags)&~ST0_IEC);
 176
 177         for (i = 0; i < size; i += 0x080) {
 178                 asm(    "sb\t$0, 0x000(%0)\n\t"
 179                         "sb\t$0, 0x004(%0)\n\t"
 180                         "sb\t$0, 0x008(%0)\n\t"
 181                         "sb\t$0, 0x00c(%0)\n\t"
 182                         "sb\t$0, 0x010(%0)\n\t"
 183                         "sb\t$0, 0x014(%0)\n\t"
 184                         "sb\t$0, 0x018(%0)\n\t"
 185                         "sb\t$0, 0x01c(%0)\n\t"
 186                         "sb\t$0, 0x020(%0)\n\t"
 187                         "sb\t$0, 0x024(%0)\n\t"
 188                         "sb\t$0, 0x028(%0)\n\t"
 189                         "sb\t$0, 0x02c(%0)\n\t"
 190                         "sb\t$0, 0x030(%0)\n\t"
 191                         "sb\t$0, 0x034(%0)\n\t"
 192                         "sb\t$0, 0x038(%0)\n\t"
 193                         "sb\t$0, 0x03c(%0)\n\t"
 194                         "sb\t$0, 0x040(%0)\n\t"
 195                         "sb\t$0, 0x044(%0)\n\t"
 196                         "sb\t$0, 0x048(%0)\n\t"
 197                         "sb\t$0, 0x04c(%0)\n\t"
 198                         "sb\t$0, 0x050(%0)\n\t"
 199                         "sb\t$0, 0x054(%0)\n\t"
 200                         "sb\t$0, 0x058(%0)\n\t"
 201                         "sb\t$0, 0x05c(%0)\n\t"
 202                         "sb\t$0, 0x060(%0)\n\t"
 203                         "sb\t$0, 0x064(%0)\n\t"
 204                         "sb\t$0, 0x068(%0)\n\t"
 205                         "sb\t$0, 0x06c(%0)\n\t"
 206                         "sb\t$0, 0x070(%0)\n\t"
 207                         "sb\t$0, 0x074(%0)\n\t"
 208                         "sb\t$0, 0x078(%0)\n\t"
 209                         "sb\t$0, 0x07c(%0)\n\t"
 210                         : : "r" (p) );
 211                 p += 0x080;
 212         }
 213
 214         write_c0_status(flags);
 215 }
 216
 217 static inline void r3k_flush_cache_all(void)
 218 {
 219 }
 220
 221 static inline void r3k___flush_cache_all(void)
 222 {
 223         r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
 224         r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
 225 }
 226
 227 static void r3k_flush_cache_mm(struct mm_struct *mm)
 228 {
 229 }
 230
 231 static void r3k_flush_cache_range(struct vm_area_struct *vma,
 232                                   unsigned long start, unsigned long end)
 233 {
 234 }
 235
 236 static void r3k_flush_cache_page(struct vm_area_struct *vma,
 237                                  unsigned long addr, unsigned long pfn)
 238 {
 239         unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
 240         int exec = vma->vm_flags & VM_EXEC;
 241         struct mm_struct *mm = vma->vm_mm;
 242         pgd_t *pgdp;
 243         pud_t *pudp;
 244         pmd_t *pmdp;
 245         pte_t *ptep;
 246
 247         pr_debug("cpage[%08lx,%08lx]\n",
 248                  cpu_context(smp_processor_id(), mm), addr);
 249
 250         /* No ASID => no such page in the cache.  */
 251         if (cpu_context(smp_processor_id(), mm) == 0)
 252                 return;
 253
 254         pgdp = pgd_offset(mm, addr);
 255         pudp = pud_offset(pgdp, addr);
 256         pmdp = pmd_offset(pudp, addr);
 257         ptep = pte_offset(pmdp, addr);
 258
 259         /* Invalid => no such page in the cache.  */
 260         if (!(pte_val(*ptep) & _PAGE_PRESENT))
 261                 return;
 262
 263         r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
 264         if (exec)
 265                 r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
 266 }
 267
 268 static void local_r3k_flush_data_cache_page(void *addr)
 269 {
 270 }
 271
 272 static void r3k_flush_data_cache_page(unsigned long addr)
 273 {
 274 }
 275
 276 static void r3k_flush_cache_sigtramp(unsigned long addr)
 277 {
 278         unsigned long flags;
 279
 280         pr_debug("csigtramp[%08lx]\n", addr);
 281
 282         flags = read_c0_status();
 283
 284         write_c0_status(flags&~ST0_IEC);
 285
 286         /* Fill the TLB to avoid an exception with caches isolated. */
 287         asm(    "lw\t$0, 0x000(%0)\n\t"
 288                 "lw\t$0, 0x004(%0)\n\t"
 289                 : : "r" (addr) );
 290
 291         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
 292
 293         asm(    "sb\t$0, 0x000(%0)\n\t"
 294                 "sb\t$0, 0x004(%0)\n\t"
 295                 : : "r" (addr) );
 296
 297         write_c0_status(flags);
 298 }
 299
 300 static void r3k_flush_kernel_vmap_range(unsigned long vaddr, int size)
 301 {
 302         BUG();
 303 }
 304
 305 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
 306 {
 307         /* Catch bad driver code */
 308         BUG_ON(size == 0);
 309
 310         iob();
 311         r3k_flush_dcache_range(start, start + size);
 312 }
 313
 314 void r3k_cache_init(void)
 315 {
 316         extern void build_clear_page(void);
 317         extern void build_copy_page(void);
 318
 319         r3k_probe_cache();
 320
 321         flush_cache_all = r3k_flush_cache_all;
 322         __flush_cache_all = r3k___flush_cache_all;
 323         flush_cache_mm = r3k_flush_cache_mm;
 324         flush_cache_range = r3k_flush_cache_range;
 325         flush_cache_page = r3k_flush_cache_page;
 326         flush_icache_range = r3k_flush_icache_range;
 327         local_flush_icache_range = r3k_flush_icache_range;
 328
 329         __flush_kernel_vmap_range = r3k_flush_kernel_vmap_range;
 330
 331         flush_cache_sigtramp = r3k_flush_cache_sigtramp;
 332         local_flush_data_cache_page = local_r3k_flush_data_cache_page;
 333         flush_data_cache_page = r3k_flush_data_cache_page;
 334
 335         _dma_cache_wback_inv = r3k_dma_cache_wback_inv;
 336         _dma_cache_wback = r3k_dma_cache_wback_inv;
 337         _dma_cache_inv = r3k_dma_cache_wback_inv;
 338
 339         printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
 340                 icache_size >> 10, icache_lsize);
 341         printk("Primary data cache %ldkB, linesize %ld bytes.\n",
 342                 dcache_size >> 10, dcache_lsize);
 343
 344         build_clear_page();
 345         build_copy_page();
 346 }