release/src-rt-6.x.4708/linux/linux-2.6.36/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, 2007  Maciej W. Rozycki
  11  */
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/sched.h>
  15 #include <linux/smp.h>
  16 #include <linux/mm.h>
  17
  18 #include <asm/page.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/mmu_context.h>
  21 #include <asm/system.h>
  22 #include <asm/isadep.h>
  23 #include <asm/io.h>
  24 #include <asm/bootinfo.h>
  25 #include <asm/cpu.h>
  26
  27 static unsigned long icache_size, dcache_size;          /* Size in bytes */
  28 static unsigned long icache_lsize, dcache_lsize;        /* Size in bytes */
  29
  30 unsigned long __cpuinit r3k_cache_size(unsigned long ca_flags)
  31 {
  32         unsigned long flags, status, dummy, size;
  33         volatile unsigned long *p;
  34
  35         p = (volatile unsigned long *) KSEG0;
  36
  37         flags = read_c0_status();
  38
  39         /* isolate cache space */
  40         write_c0_status((ca_flags|flags)&~ST0_IEC);
  41
  42         *p = 0xa5a55a5a;
  43         dummy = *p;
  44         status = read_c0_status();
  45
  46         if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
  47                 size = 0;
  48         } else {
  49                 for (size = 128; size <= 0x40000; size <<= 1)
  50                         *(p + size) = 0;
  51                 *p = -1;
  52                 for (size = 128;
  53                      (size <= 0x40000) && (*(p + size) == 0);
  54                      size <<= 1)
  55                         ;
  56                 if (size > 0x40000)
  57                         size = 0;
  58         }
  59
  60         write_c0_status(flags);
  61
  62         return size * sizeof(*p);
  63 }
  64
  65 unsigned long __cpuinit r3k_cache_lsize(unsigned long ca_flags)
  66 {
  67         unsigned long flags, status, lsize, i;
  68         volatile unsigned long *p;
  69
  70         p = (volatile unsigned long *) KSEG0;
  71
  72         flags = read_c0_status();
  73
  74         /* isolate cache space */
  75         write_c0_status((ca_flags|flags)&~ST0_IEC);
  76
  77         for (i = 0; i < 128; i++)
  78                 *(p + i) = 0;
  79         *(volatile unsigned char *)p = 0;
  80         for (lsize = 1; lsize < 128; lsize <<= 1) {
  81                 *(p + lsize);
  82                 status = read_c0_status();
  83                 if (!(status & ST0_CM))
  84                         break;
  85         }
  86         for (i = 0; i < 128; i += lsize)
  87                 *(volatile unsigned char *)(p + i) = 0;
  88
  89         write_c0_status(flags);
  90
  91         return lsize * sizeof(*p);
  92 }
  93
  94 static void __cpuinit r3k_probe_cache(void)
  95 {
  96         dcache_size = r3k_cache_size(ST0_ISC);
  97         if (dcache_size)
  98                 dcache_lsize = r3k_cache_lsize(ST0_ISC);
  99
 100         icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
 101         if (icache_size)
 102                 icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
 103 }
 104
 105 static void r3k_flush_icache_range(unsigned long start, unsigned long end)
 106 {
 107         unsigned long size, i, flags;
 108         volatile unsigned char *p;
 109
 110         size = end - start;
 111         if (size > icache_size || KSEGX(start) != KSEG0) {
 112                 start = KSEG0;
 113                 size = icache_size;
 114         }
 115         p = (char *)start;
 116
 117         flags = read_c0_status();
 118
 119         /* isolate cache space */
 120         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
 121
 122         for (i = 0; i < size; i += 0x080) {
 123                 asm(    "sb\t$0, 0x000(%0)\n\t"
 124                         "sb\t$0, 0x004(%0)\n\t"
 125                         "sb\t$0, 0x008(%0)\n\t"
 126                         "sb\t$0, 0x00c(%0)\n\t"
 127                         "sb\t$0, 0x010(%0)\n\t"
 128                         "sb\t$0, 0x014(%0)\n\t"
 129                         "sb\t$0, 0x018(%0)\n\t"
 130                         "sb\t$0, 0x01c(%0)\n\t"
 131                         "sb\t$0, 0x020(%0)\n\t"
 132                         "sb\t$0, 0x024(%0)\n\t"
 133                         "sb\t$0, 0x028(%0)\n\t"
 134                         "sb\t$0, 0x02c(%0)\n\t"
 135                         "sb\t$0, 0x030(%0)\n\t"
 136                         "sb\t$0, 0x034(%0)\n\t"
 137                         "sb\t$0, 0x038(%0)\n\t"
 138                         "sb\t$0, 0x03c(%0)\n\t"
 139                         "sb\t$0, 0x040(%0)\n\t"
 140                         "sb\t$0, 0x044(%0)\n\t"
 141                         "sb\t$0, 0x048(%0)\n\t"
 142                         "sb\t$0, 0x04c(%0)\n\t"
 143                         "sb\t$0, 0x050(%0)\n\t"
 144                         "sb\t$0, 0x054(%0)\n\t"
 145                         "sb\t$0, 0x058(%0)\n\t"
 146                         "sb\t$0, 0x05c(%0)\n\t"
 147                         "sb\t$0, 0x060(%0)\n\t"
 148                         "sb\t$0, 0x064(%0)\n\t"
 149                         "sb\t$0, 0x068(%0)\n\t"
 150                         "sb\t$0, 0x06c(%0)\n\t"
 151                         "sb\t$0, 0x070(%0)\n\t"
 152                         "sb\t$0, 0x074(%0)\n\t"
 153                         "sb\t$0, 0x078(%0)\n\t"
 154                         "sb\t$0, 0x07c(%0)\n\t"
 155                         : : "r" (p) );
 156                 p += 0x080;
 157         }
 158
 159         write_c0_status(flags);
 160 }
 161
 162 static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
 163 {
 164         unsigned long size, i, flags;
 165         volatile unsigned char *p;
 166
 167         size = end - start;
 168         if (size > dcache_size || KSEGX(start) != KSEG0) {
 169                 start = KSEG0;
 170                 size = dcache_size;
 171         }
 172         p = (char *)start;
 173
 174         flags = read_c0_status();
 175
 176         /* isolate cache space */
 177         write_c0_status((ST0_ISC|flags)&~ST0_IEC);
 178
 179         for (i = 0; i < size; i += 0x080) {
 180                 asm(    "sb\t$0, 0x000(%0)\n\t"
 181                         "sb\t$0, 0x004(%0)\n\t"
 182                         "sb\t$0, 0x008(%0)\n\t"
 183                         "sb\t$0, 0x00c(%0)\n\t"
 184                         "sb\t$0, 0x010(%0)\n\t"
 185                         "sb\t$0, 0x014(%0)\n\t"
 186                         "sb\t$0, 0x018(%0)\n\t"
 187                         "sb\t$0, 0x01c(%0)\n\t"
 188                         "sb\t$0, 0x020(%0)\n\t"
 189                         "sb\t$0, 0x024(%0)\n\t"
 190                         "sb\t$0, 0x028(%0)\n\t"
 191                         "sb\t$0, 0x02c(%0)\n\t"
 192                         "sb\t$0, 0x030(%0)\n\t"
 193                         "sb\t$0, 0x034(%0)\n\t"
 194                         "sb\t$0, 0x038(%0)\n\t"
 195                         "sb\t$0, 0x03c(%0)\n\t"
 196                         "sb\t$0, 0x040(%0)\n\t"
 197                         "sb\t$0, 0x044(%0)\n\t"
 198                         "sb\t$0, 0x048(%0)\n\t"
 199                         "sb\t$0, 0x04c(%0)\n\t"
 200                         "sb\t$0, 0x050(%0)\n\t"
 201                         "sb\t$0, 0x054(%0)\n\t"
 202                         "sb\t$0, 0x058(%0)\n\t"
 203                         "sb\t$0, 0x05c(%0)\n\t"
 204                         "sb\t$0, 0x060(%0)\n\t"
 205                         "sb\t$0, 0x064(%0)\n\t"
 206                         "sb\t$0, 0x068(%0)\n\t"
 207                         "sb\t$0, 0x06c(%0)\n\t"
 208                         "sb\t$0, 0x070(%0)\n\t"
 209                         "sb\t$0, 0x074(%0)\n\t"
 210                         "sb\t$0, 0x078(%0)\n\t"
 211                         "sb\t$0, 0x07c(%0)\n\t"
 212                         : : "r" (p) );
 213                 p += 0x080;
 214         }
 215
 216         write_c0_status(flags);
 217 }
 218
 219 static inline void r3k_flush_cache_all(void)
 220 {
 221 }
 222
 223 static inline void r3k___flush_cache_all(void)
 224 {
 225         r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
 226         r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
 227 }
 228
 229 static void r3k_flush_cache_mm(struct mm_struct *mm)
 230 {
 231 }
 232
 233 static void r3k_flush_cache_range(struct vm_area_struct *vma,
 234                                   unsigned long start, unsigned long end)
 235 {
 236 }
 237
 238 static void r3k_flush_cache_page(struct vm_area_struct *vma,
 239                                  unsigned long addr, unsigned long pfn)
 240 {
 241         unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
 242         int exec = vma->vm_flags & VM_EXEC;
 243         struct mm_struct *mm = vma->vm_mm;
 244         pgd_t *pgdp;
 245         pud_t *pudp;
 246         pmd_t *pmdp;
 247         pte_t *ptep;
 248
 249         pr_debug("cpage[%08lx,%08lx]\n",
 250                  cpu_context(smp_processor_id(), mm), addr);
 251
 252         /* No ASID => no such page in the cache.  */
 253         if (cpu_context(smp_processor_id(), mm) == 0)
 254                 return;
 255
 256         pgdp = pgd_offset(mm, addr);
 257         pudp = pud_offset(pgdp, addr);
 258         pmdp = pmd_offset(pudp, addr);
 259         ptep = pte_offset(pmdp, addr);
 260
 261         /* Invalid => no such page in the cache.  */
 262         if (!(pte_val(*ptep) & _PAGE_PRESENT))
 263                 return;
 264
 265         r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
 266         if (exec)
 267                 r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
 268 }
 269
 270 static void local_r3k_flush_data_cache_page(void *addr)
 271 {
 272 }
 273
 274 static void r3k_flush_data_cache_page(unsigned long addr)
 275 {
 276 }
 277
 278 static void r3k_flush_cache_sigtramp(unsigned long addr)
 279 {
 280         unsigned long flags;
 281
 282         pr_debug("csigtramp[%08lx]\n", addr);
 283
 284         flags = read_c0_status();
 285
 286         write_c0_status(flags&~ST0_IEC);
 287
 288         /* Fill the TLB to avoid an exception with caches isolated. */
 289         asm(    "lw\t$0, 0x000(%0)\n\t"
 290                 "lw\t$0, 0x004(%0)\n\t"
 291                 : : "r" (addr) );
 292
 293         write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
 294
 295         asm(    "sb\t$0, 0x000(%0)\n\t"
 296                 "sb\t$0, 0x004(%0)\n\t"
 297                 : : "r" (addr) );
 298
 299         write_c0_status(flags);
 300 }
 301
 302 static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
 303 {
 304         /* Catch bad driver code */
 305         BUG_ON(size == 0);
 306
 307         iob();
 308         r3k_flush_dcache_range(start, start + size);
 309 }
 310
 311 void __cpuinit r3k_cache_init(void)
 312 {
 313         extern void build_clear_page(void);
 314         extern void build_copy_page(void);
 315
 316         r3k_probe_cache();
 317
 318         flush_cache_all = r3k_flush_cache_all;
 319         __flush_cache_all = r3k___flush_cache_all;
 320         flush_cache_mm = r3k_flush_cache_mm;
 321         flush_cache_range = r3k_flush_cache_range;
 322         flush_cache_page = r3k_flush_cache_page;
 323         flush_icache_range = r3k_flush_icache_range;
 324         local_flush_icache_range = r3k_flush_icache_range;
 325
 326         flush_cache_sigtramp = r3k_flush_cache_sigtramp;
 327         local_flush_data_cache_page = local_r3k_flush_data_cache_page;
 328         flush_data_cache_page = r3k_flush_data_cache_page;
 329
 330         _dma_cache_wback_inv = r3k_dma_cache_wback_inv;
 331         _dma_cache_wback = r3k_dma_cache_wback_inv;
 332         _dma_cache_inv = r3k_dma_cache_wback_inv;
 333
 334         printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
 335                 icache_size >> 10, icache_lsize);
 336         printk("Primary data cache %ldkB, linesize %ld bytes.\n",
 337                 dcache_size >> 10, dcache_lsize);
 338
 339         build_clear_page();
 340         build_copy_page();
 341 }