arch/mips/mm/init.c

   1 /* $Id: init.c,v 1.13 1999/05/01 22:40:40 ralf Exp $
   2  *
   3  * This file is subject to the terms and conditions of the GNU General Public
   4  * License.  See the file "COPYING" in the main directory of this archive
   5  * for more details.
   6  *
   7  * Copyright (C) 1994 - 1998 by Ralf Baechle
   8  */
   9 #include <linux/config.h>
  10 #include <linux/init.h>
  11 #include <linux/signal.h>
  12 #include <linux/sched.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/string.h>
  16 #include <linux/types.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/mman.h>
  20 #include <linux/mm.h>
  21 #include <linux/swap.h>
  22 #include <linux/swapctl.h>
  23 #ifdef CONFIG_BLK_DEV_INITRD
  24 #include <linux/blk.h>
  25 #endif
  26
  27 #include <asm/bootinfo.h>
  28 #include <asm/cachectl.h>
  29 #include <asm/dma.h>
  30 #include <asm/jazzdma.h>
  31 #include <asm/system.h>
  32 #include <asm/pgtable.h>
  33 #ifdef CONFIG_SGI
  34 #include <asm/sgialib.h>
  35 #endif
  36 #include <asm/mmu_context.h>
  37
  38 extern void show_net_buffers(void);
  39
  40 void __bad_pte_kernel(pmd_t *pmd)
  41 {
  42         printk("Bad pmd in pte_alloc_kernel: %08lx\n", pmd_val(*pmd));
  43         pmd_val(*pmd) = BAD_PAGETABLE;
  44 }
  45
  46 void __bad_pte(pmd_t *pmd)
  47 {
  48         printk("Bad pmd in pte_alloc: %08lx\n", pmd_val(*pmd));
  49         pmd_val(*pmd) = BAD_PAGETABLE;
  50 }
  51
  52 pte_t *get_pte_kernel_slow(pmd_t *pmd, unsigned long offset)
  53 {
  54         pte_t *page;
  55
  56         page = (pte_t *) __get_free_page(GFP_USER);
  57         if (pmd_none(*pmd)) {
  58                 if (page) {
  59                         clear_page((unsigned long)page);
  60                         pmd_val(*pmd) = (unsigned long)page;
  61                         return page + offset;
  62                 }
  63                 pmd_val(*pmd) = BAD_PAGETABLE;
  64                 return NULL;
  65         }
  66         free_page((unsigned long)page);
  67         if (pmd_bad(*pmd)) {
  68                 __bad_pte_kernel(pmd);
  69                 return NULL;
  70         }
  71         return (pte_t *) pmd_page(*pmd) + offset;
  72 }
  73
  74 pte_t *get_pte_slow(pmd_t *pmd, unsigned long offset)
  75 {
  76         pte_t *page;
  77
  78         page = (pte_t *) __get_free_page(GFP_KERNEL);
  79         if (pmd_none(*pmd)) {
  80                 if (page) {
  81                         clear_page((unsigned long)page);
  82                         pmd_val(*pmd) = (unsigned long)page;
  83                         return page + offset;
  84                 }
  85                 pmd_val(*pmd) = BAD_PAGETABLE;
  86                 return NULL;
  87         }
  88         free_page((unsigned long)page);
  89         if (pmd_bad(*pmd)) {
  90                 __bad_pte(pmd);
  91                 return NULL;
  92         }
  93         return (pte_t *) pmd_page(*pmd) + offset;
  94 }
  95
  96
  97 asmlinkage int sys_cacheflush(void *addr, int bytes, int cache)
  98 {
  99         /* XXX Just get it working for now... */
 100         flush_cache_all();
 101         return 0;
 102 }
 103
 104 /*
 105  * We have upto 8 empty zeroed pages so we can map one of the right colour
 106  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
 107  * where we have to avoid VCED / VECI exceptions for good performance at
 108  * any price.  Since page is never written to after the initialization we
 109  * don't have to care about aliases on other CPUs.
 110  */
 111 unsigned long empty_zero_page, zero_page_mask;
 112
 113 static inline unsigned long setup_zero_pages(void)
 114 {
 115         unsigned long order, size, pg;
 116
 117         switch (mips_cputype) {
 118         case CPU_R4000SC:
 119         case CPU_R4000MC:
 120         case CPU_R4400SC:
 121         case CPU_R4400MC:
 122                 order = 3;
 123                 break;
 124         default:
 125                 order = 0;
 126         }
 127
 128         empty_zero_page = __get_free_pages(GFP_KERNEL, order);
 129         if (!empty_zero_page)
 130                 panic("Oh boy, that early out of memory?");
 131
 132         pg = MAP_NR(empty_zero_page);
 133         while(pg < MAP_NR(empty_zero_page) + (1 << order)) {
 134                 set_bit(PG_reserved, &mem_map[pg].flags);
 135                 atomic_set(&mem_map[pg].count, 0);
 136                 pg++;
 137         }
 138
 139         size = PAGE_SIZE << order;
 140         zero_page_mask = (size - 1) & PAGE_MASK;
 141         memset((void *)empty_zero_page, 0, size);
 142
 143         return size;
 144 }
 145
 146 int do_check_pgt_cache(int low, int high)
 147 {
 148         int freed = 0;
 149
 150         if(pgtable_cache_size > high) {
 151                 do {
 152                         if(pgd_quicklist)
 153                                 free_pgd_slow(get_pgd_fast()), freed++;
 154                         if(pmd_quicklist)
 155                                 free_pmd_slow(get_pmd_fast()), freed++;
 156                         if(pte_quicklist)
 157                                 free_pte_slow(get_pte_fast()), freed++;
 158                 } while(pgtable_cache_size > low);
 159         }
 160         return freed;
 161 }
 162
 163 /*
 164  * BAD_PAGE is the page that is used for page faults when linux
 165  * is out-of-memory. Older versions of linux just did a
 166  * do_exit(), but using this instead means there is less risk
 167  * for a process dying in kernel mode, possibly leaving a inode
 168  * unused etc..
 169  *
 170  * BAD_PAGETABLE is the accompanying page-table: it is initialized
 171  * to point to BAD_PAGE entries.
 172  *
 173  * ZERO_PAGE is a special page that is used for zero-initialized
 174  * data and COW.
 175  */
 176 pte_t * __bad_pagetable(void)
 177 {
 178         extern char empty_bad_page_table[PAGE_SIZE];
 179         unsigned long page;
 180         unsigned long dummy1, dummy2;
 181 #if (_MIPS_ISA == _MIPS_ISA_MIPS3) || (_MIPS_ISA == _MIPS_ISA_MIPS4)
 182         unsigned long dummy3;
 183 #endif
 184
 185         page = (unsigned long) empty_bad_page_table;
 186         /*
 187          * As long as we only save the low 32 bit of the 64 bit wide
 188          * R4000 registers on interrupt we cannot use 64 bit memory accesses
 189          * to the main memory.
 190          */
 191 #if (_MIPS_ISA == _MIPS_ISA_MIPS3) || (_MIPS_ISA == _MIPS_ISA_MIPS4)
 192         /*
 193          * Use 64bit code even for Linux/MIPS 32bit on R4000
 194          */
 195         __asm__ __volatile__(
 196                 ".set\tnoreorder\n"
 197                 ".set\tnoat\n\t"
 198                 ".set\tmips3\n\t"
 199                 "dsll32\t$1,%2,0\n\t"
 200                 "dsrl32\t%2,$1,0\n\t"
 201                 "or\t%2,$1\n"
 202                 "1:\tsd\t%2,(%0)\n\t"
 203                 "subu\t%1,1\n\t"
 204                 "bnez\t%1,1b\n\t"
 205                 "addiu\t%0,8\n\t"
 206                 ".set\tmips0\n\t"
 207                 ".set\tat\n"
 208                 ".set\treorder"
 209                 :"=r" (dummy1),
 210                  "=r" (dummy2),
 211                  "=r" (dummy3)
 212                 :"0" (page),
 213                  "1" (PAGE_SIZE/8),
 214                  "2" (pte_val(BAD_PAGE)));
 215 #else /* (_MIPS_ISA == _MIPS_ISA_MIPS1) || (_MIPS_ISA == _MIPS_ISA_MIPS2) */
 216         __asm__ __volatile__(
 217                 ".set\tnoreorder\n"
 218                 "1:\tsw\t%2,(%0)\n\t"
 219                 "subu\t%1,1\n\t"
 220                 "bnez\t%1,1b\n\t"
 221                 "addiu\t%0,4\n\t"
 222                 ".set\treorder"
 223                 :"=r" (dummy1),
 224                  "=r" (dummy2)
 225                 :"r" (pte_val(BAD_PAGE)),
 226                  "0" (page),
 227                  "1" (PAGE_SIZE/4));
 228 #endif
 229
 230         return (pte_t *)page;
 231 }
 232
 233 pte_t __bad_page(void)
 234 {
 235         extern char empty_bad_page[PAGE_SIZE];
 236         unsigned long page = (unsigned long)empty_bad_page;
 237
 238         clear_page(page);
 239         return pte_mkdirty(mk_pte(page, PAGE_SHARED));
 240 }
 241
 242 void show_mem(void)
 243 {
 244         int i, free = 0, total = 0, reserved = 0;
 245         int shared = 0, cached = 0;
 246
 247         printk("Mem-info:\n");
 248         show_free_areas();
 249         printk("Free swap:       %6dkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 250         i = max_mapnr;
 251         while (i-- > 0) {
 252                 total++;
 253                 if (PageReserved(mem_map+i))
 254                         reserved++;
 255                 else if (PageSwapCache(mem_map+i))
 256                         cached++;
 257                 else if (!atomic_read(&mem_map[i].count))
 258                         free++;
 259                 else
 260                         shared += atomic_read(&mem_map[i].count) - 1;
 261         }
 262         printk("%d pages of RAM\n", total);
 263         printk("%d reserved pages\n", reserved);
 264         printk("%d pages shared\n", shared);
 265         printk("%d pages swap cached\n",cached);
 266         printk("%ld pages in page table cache\n",pgtable_cache_size);
 267         printk("%d free pages\n", free);
 268         show_buffers();
 269 #ifdef CONFIG_NET
 270         show_net_buffers();
 271 #endif
 272 }
 273
 274 extern unsigned long free_area_init(unsigned long, unsigned long);
 275
 276 __initfunc(unsigned long paging_init(unsigned long start_mem, unsigned long end_mem))
 277 {
 278         /* Initialize the entire pgd.  */
 279         pgd_init((unsigned long)swapper_pg_dir);
 280         pgd_init((unsigned long)swapper_pg_dir + PAGE_SIZE / 2);
 281         return free_area_init(start_mem, end_mem);
 282 }
 283
 284 __initfunc(void mem_init(unsigned long start_mem, unsigned long end_mem))
 285 {
 286         int codepages = 0;
 287         int datapages = 0;
 288         unsigned long tmp;
 289         extern int _etext, _ftext;
 290
 291 #ifdef CONFIG_MIPS_JAZZ
 292         if (mips_machgroup == MACH_GROUP_JAZZ)
 293                 start_mem = vdma_init(start_mem, end_mem);
 294 #endif
 295
 296         end_mem &= PAGE_MASK;
 297         max_mapnr = MAP_NR(end_mem);
 298         high_memory = (void *)end_mem;
 299         num_physpages = 0;
 300
 301         /* mark usable pages in the mem_map[] */
 302         start_mem = PAGE_ALIGN(start_mem);
 303
 304         for(tmp = MAP_NR(start_mem);tmp < max_mapnr;tmp++)
 305                 clear_bit(PG_reserved, &mem_map[tmp].flags);
 306
 307         prom_fixup_mem_map(start_mem, (unsigned long)high_memory);
 308
 309         for (tmp = PAGE_OFFSET; tmp < end_mem; tmp += PAGE_SIZE) {
 310                 /*
 311                  * This is only for PC-style DMA.  The onboard DMA
 312                  * of Jazz and Tyne machines is completely different and
 313                  * not handled via a flag in mem_map_t.
 314                  */
 315                 if (tmp >= MAX_DMA_ADDRESS)
 316                         clear_bit(PG_DMA, &mem_map[MAP_NR(tmp)].flags);
 317                 if (PageReserved(mem_map+MAP_NR(tmp))) {
 318                         if ((tmp < (unsigned long) &_etext) &&
 319                             (tmp >= (unsigned long) &_ftext))
 320                                 codepages++;
 321                         else if ((tmp < start_mem) &&
 322                                  (tmp > (unsigned long) &_etext))
 323                                 datapages++;
 324                         continue;
 325                 }
 326                 num_physpages++;
 327                 atomic_set(&mem_map[MAP_NR(tmp)].count, 1);
 328 #ifdef CONFIG_BLK_DEV_INITRD
 329                 if (!initrd_start || (tmp < initrd_start || tmp >=
 330                     initrd_end))
 331 #endif
 332                         free_page(tmp);
 333         }
 334         tmp = nr_free_pages << PAGE_SHIFT;
 335
 336         /* Setup zeroed pages.  */
 337         tmp -= setup_zero_pages();
 338
 339         printk("Memory: %luk/%luk available (%dk kernel code, %dk data)\n",
 340                 tmp >> 10,
 341                 max_mapnr << (PAGE_SHIFT-10),
 342                 codepages << (PAGE_SHIFT-10),
 343                 datapages << (PAGE_SHIFT-10));
 344 }
 345
 346 extern char __init_begin, __init_end;
 347
 348 void free_initmem(void)
 349 {
 350         unsigned long addr;
 351
 352         prom_free_prom_memory ();
 353
 354         addr = (unsigned long)(&__init_begin);
 355         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 356                 mem_map[MAP_NR(addr)].flags &= ~(1 << PG_reserved);
 357                 atomic_set(&mem_map[MAP_NR(addr)].count, 1);
 358                 free_page(addr);
 359         }
 360         printk("Freeing unused kernel memory: %dk freed\n",
 361                (&__init_end - &__init_begin) >> 10);
 362 }
 363
 364 void si_meminfo(struct sysinfo *val)
 365 {
 366         int i;
 367
 368         i = MAP_NR(high_memory);
 369         val->totalram = 0;
 370         val->sharedram = 0;
 371         val->freeram = nr_free_pages << PAGE_SHIFT;
 372         val->bufferram = buffermem;
 373         while (i-- > 0)  {
 374                 if (PageReserved(mem_map+i))
 375                         continue;
 376                 val->totalram++;
 377                 if (!atomic_read(&mem_map[i].count))
 378                         continue;
 379                 val->sharedram += atomic_read(&mem_map[i].count) - 1;
 380         }
 381         val->totalram <<= PAGE_SHIFT;
 382         val->sharedram <<= PAGE_SHIFT;
 383         return;
 384 }
 385
 386 /* Fixup an immediate instruction  */
 387 __initfunc(static void __i_insn_fixup(unsigned int **start, unsigned int **stop,
 388                          unsigned int i_const))
 389 {
 390         unsigned int **p, *ip;
 391
 392         for (p = start;p < stop; p++) {
 393                 ip = *p;
 394                 *ip = (*ip & 0xffff0000) | i_const;
 395         }
 396 }
 397
 398 #define i_insn_fixup(section, const)                                      \
 399 do {                                                                      \
 400         extern unsigned int *__start_ ## section;                         \
 401         extern unsigned int *__stop_ ## section;                          \
 402         __i_insn_fixup(&__start_ ## section, &__stop_ ## section, const); \
 403 } while(0)
 404
 405 /* Caller is assumed to flush the caches before the first context switch.  */
 406 __initfunc(void __asid_setup(unsigned int inc, unsigned int mask,
 407                              unsigned int version_mask,
 408                              unsigned int first_version))
 409 {
 410         i_insn_fixup(__asid_inc, inc);
 411         i_insn_fixup(__asid_mask, mask);
 412         i_insn_fixup(__asid_version_mask, version_mask);
 413         i_insn_fixup(__asid_first_version, first_version);
 414
 415         asid_cache = first_version;
 416 }