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