arch/mips/mm/init.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) 1994 - 2000 by Ralf Baechle
   7  * Copyright (C) 2000 Silicon Graphics, Inc.
   8  *
   9  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
  10  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
  11  */
  12 #include <linux/config.h>
  13 #include <linux/init.h>
  14 #include <linux/signal.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/string.h>
  19 #include <linux/types.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/mman.h>
  23 #include <linux/mm.h>
  24 #include <linux/bootmem.h>
  25 #include <linux/highmem.h>
  26 #include <linux/swap.h>
  27 #include <linux/swapctl.h>
  28 #include <linux/blk.h>
  29
  30 #include <asm/bootinfo.h>
  31 #include <asm/cachectl.h>
  32 #include <asm/cpu.h>
  33 #include <asm/dma.h>
  34 #include <asm/jazzdma.h>
  35 #include <asm/system.h>
  36 #include <asm/pgtable.h>
  37 #include <asm/pgalloc.h>
  38 #include <asm/mmu_context.h>
  39 #include <asm/tlb.h>
  40
  41 mmu_gather_t mmu_gathers[NR_CPUS];
  42 unsigned long highstart_pfn, highend_pfn;
  43 static unsigned long totalram_pages;
  44 static unsigned long totalhigh_pages;
  45
  46 void pgd_init(unsigned long page)
  47 {
  48         unsigned long *p = (unsigned long *) page;
  49         int i;
  50
  51         for (i = 0; i < USER_PTRS_PER_PGD; i+=8) {
  52                 p[i + 0] = (unsigned long) invalid_pte_table;
  53                 p[i + 1] = (unsigned long) invalid_pte_table;
  54                 p[i + 2] = (unsigned long) invalid_pte_table;
  55                 p[i + 3] = (unsigned long) invalid_pte_table;
  56                 p[i + 4] = (unsigned long) invalid_pte_table;
  57                 p[i + 5] = (unsigned long) invalid_pte_table;
  58                 p[i + 6] = (unsigned long) invalid_pte_table;
  59                 p[i + 7] = (unsigned long) invalid_pte_table;
  60         }
  61 }
  62
  63 /*
  64  * We have upto 8 empty zeroed pages so we can map one of the right colour
  65  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  66  * where we have to avoid VCED / VECI exceptions for good performance at
  67  * any price.  Since page is never written to after the initialization we
  68  * don't have to care about aliases on other CPUs.
  69  */
  70 unsigned long empty_zero_page, zero_page_mask;
  71
  72 static inline unsigned long setup_zero_pages(void)
  73 {
  74         unsigned long order, size;
  75         struct page *page;
  76
  77         if (cpu_has_vce)
  78                 order = 3;
  79         else
  80                 order = 0;
  81
  82         empty_zero_page = __get_free_pages(GFP_KERNEL, order);
  83         if (!empty_zero_page)
  84                 panic("Oh boy, that early out of memory?");
  85
  86         page = virt_to_page(empty_zero_page);
  87         while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
  88                 set_bit(PG_reserved, &page->flags);
  89                 set_page_count(page, 0);
  90                 page++;
  91         }
  92
  93         size = PAGE_SIZE << order;
  94         zero_page_mask = (size - 1) & PAGE_MASK;
  95         memset((void *)empty_zero_page, 0, size);
  96
  97         return 1UL << order;
  98 }
  99
 100 int do_check_pgt_cache(int low, int high)
 101 {
 102         int freed = 0;
 103
 104         if (pgtable_cache_size > high) {
 105                 do {
 106                         if (pgd_quicklist)
 107                                 free_pgd_slow(get_pgd_fast()), freed++;
 108                         if (pmd_quicklist)
 109                                 free_pmd_slow(get_pmd_fast()), freed++;
 110                         if (pte_quicklist)
 111                                 free_pte_slow(get_pte_fast()), freed++;
 112                 } while (pgtable_cache_size > low);
 113         }
 114         return freed;
 115 }
 116
 117 #if CONFIG_HIGHMEM
 118 pte_t *kmap_pte;
 119 pgprot_t kmap_prot;
 120
 121 #define kmap_get_fixmap_pte(vaddr)                                      \
 122         pte_offset(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
 123
 124 static void __init kmap_init(void)
 125 {
 126         unsigned long kmap_vstart;
 127
 128         /* cache the first kmap pte */
 129         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 130         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 131
 132         kmap_prot = PAGE_KERNEL;
 133 }
 134
 135 #endif /* CONFIG_HIGHMEM */
 136
 137 void show_mem(void)
 138 {
 139         int i, free = 0, total = 0, reserved = 0;
 140         int shared = 0, cached = 0;
 141
 142         printk("Mem-info:\n");
 143         show_free_areas();
 144         printk("Free swap:       %6dkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 145         i = max_mapnr;
 146         while (i-- > 0) {
 147                 total++;
 148                 if (PageReserved(mem_map+i))
 149                         reserved++;
 150                 else if (PageSwapCache(mem_map+i))
 151                         cached++;
 152                 else if (!page_count(mem_map + i))
 153                         free++;
 154                 else
 155                         shared += page_count(mem_map + i) - 1;
 156         }
 157         printk("%d pages of RAM\n", total);
 158         printk("%d reserved pages\n", reserved);
 159         printk("%d pages shared\n", shared);
 160         printk("%d pages swap cached\n",cached);
 161         printk("%ld pages in page table cache\n",pgtable_cache_size);
 162         printk("%d free pages\n", free);
 163         show_buffers();
 164 }
 165
 166 /* References to section boundaries */
 167
 168 extern char _ftext, _etext, _fdata, _edata;
 169 extern char __init_begin, __init_end;
 170
 171 #ifdef CONFIG_HIGHMEM
 172 static void __init fixrange_init (unsigned long start, unsigned long end,
 173         pgd_t *pgd_base)
 174 {
 175         pgd_t *pgd;
 176         pmd_t *pmd;
 177         pte_t *pte;
 178         int i, j;
 179         unsigned long vaddr;
 180
 181         vaddr = start;
 182         i = __pgd_offset(vaddr);
 183         j = __pmd_offset(vaddr);
 184         pgd = pgd_base + i;
 185
 186         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 187                 pmd = (pmd_t *)pgd;
 188                 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
 189                         if (pmd_none(*pmd)) {
 190                                 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 191                                 set_pmd(pmd, __pmd(pte));
 192                                 if (pte != pte_offset(pmd, 0))
 193                                         BUG();
 194                         }
 195                         vaddr += PMD_SIZE;
 196                 }
 197                 j = 0;
 198         }
 199 }
 200 #endif
 201
 202 void __init pagetable_init(void)
 203 {
 204 #ifdef CONFIG_HIGHMEM
 205         unsigned long vaddr;
 206         pgd_t *pgd, *pgd_base;
 207         pmd_t *pmd;
 208         pte_t *pte;
 209 #endif
 210
 211         /* Initialize the entire pgd.  */
 212         pgd_init((unsigned long)swapper_pg_dir);
 213         pgd_init((unsigned long)swapper_pg_dir +
 214                  sizeof(pgd_t ) * USER_PTRS_PER_PGD);
 215
 216 #ifdef CONFIG_HIGHMEM
 217         pgd_base = swapper_pg_dir;
 218
 219         /*
 220          * Fixed mappings:
 221          */
 222         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 223         fixrange_init(vaddr, 0, pgd_base);
 224
 225         /*
 226          * Permanent kmaps:
 227          */
 228         vaddr = PKMAP_BASE;
 229         fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
 230
 231         pgd = swapper_pg_dir + __pgd_offset(vaddr);
 232         pmd = pmd_offset(pgd, vaddr);
 233         pte = pte_offset(pmd, vaddr);
 234         pkmap_page_table = pte;
 235 #endif
 236 }
 237
 238 void __init paging_init(void)
 239 {
 240         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 241         unsigned long max_dma, high, low;
 242
 243         pagetable_init();
 244
 245 #ifdef CONFIG_HIGHMEM
 246         kmap_init();
 247 #endif
 248
 249         max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 250         low = max_low_pfn;
 251         high = highend_pfn;
 252
 253 #ifdef CONFIG_ISA
 254         if (low < max_dma)
 255                 zones_size[ZONE_DMA] = low;
 256         else {
 257                 zones_size[ZONE_DMA] = max_dma;
 258                 zones_size[ZONE_NORMAL] = low - max_dma;
 259         }
 260 #else
 261         zones_size[ZONE_DMA] = low;
 262 #endif
 263 #ifdef CONFIG_HIGHMEM
 264         if (cpu_has_dc_aliases) {
 265                 printk(KERN_WARNING "This processor doesn't support highmem.");
 266                 if (high - low)
 267                         printk(" %dk highmem ignored", high - low);
 268                 printk("\n");
 269         } else
 270                 zones_size[ZONE_HIGHMEM] = high - low;
 271 #endif
 272
 273         free_area_init(zones_size);
 274 }
 275
 276 #define PFN_UP(x)       (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
 277 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
 278
 279 static inline int page_is_ram(unsigned long pagenr)
 280 {
 281         int i;
 282
 283         for (i = 0; i < boot_mem_map.nr_map; i++) {
 284                 unsigned long addr, end;
 285
 286                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 287                         /* not usable memory */
 288                         continue;
 289
 290                 addr = PFN_UP(boot_mem_map.map[i].addr);
 291                 end = PFN_DOWN(boot_mem_map.map[i].addr
 292                                + boot_mem_map.map[i].size);
 293
 294                 if (pagenr >= addr && pagenr < end)
 295                         return 1;
 296         }
 297
 298         return 0;
 299 }
 300
 301 void __init mem_init(void)
 302 {
 303         unsigned long codesize, reservedpages, datasize, initsize;
 304         unsigned long tmp, ram;
 305
 306 #if defined(CONFIG_DISCONTIGMEM) && defined(CONFIG_HIGHMEM)
 307 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 308 #endif
 309
 310 #ifdef CONFIG_HIGHMEM
 311         highstart_pfn = (KSEG1 - KSEG0) >> PAGE_SHIFT;
 312         highmem_start_page = mem_map + highstart_pfn;
 313         max_mapnr = num_physpages = highend_pfn;
 314         num_mappedpages = max_low_pfn;
 315 #else
 316         max_mapnr = num_mappedpages = num_physpages = max_low_pfn;
 317 #endif
 318         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 319
 320         totalram_pages += free_all_bootmem();
 321         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 322
 323         reservedpages = ram = 0;
 324         for (tmp = 0; tmp < max_low_pfn; tmp++)
 325                 if (page_is_ram(tmp)) {
 326                         ram++;
 327                         if (PageReserved(mem_map+tmp))
 328                                 reservedpages++;
 329                 }
 330
 331 #ifdef CONFIG_HIGHMEM
 332         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 333                 struct page *page = mem_map + tmp;
 334
 335                 if (!page_is_ram(tmp)) {
 336                         SetPageReserved(page);
 337                         continue;
 338                 }
 339                 ClearPageReserved(page);
 340                 set_bit(PG_highmem, &page->flags);
 341                 atomic_set(&page->count, 1);
 342                 __free_page(page);
 343                 totalhigh_pages++;
 344         }
 345         totalram_pages += totalhigh_pages;
 346 #endif
 347
 348         codesize =  (unsigned long) &_etext - (unsigned long) &_ftext;
 349         datasize =  (unsigned long) &_edata - (unsigned long) &_fdata;
 350         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 351
 352         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 353                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 354                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 355                ram << (PAGE_SHIFT-10),
 356                codesize >> 10,
 357                reservedpages << (PAGE_SHIFT-10),
 358                datasize >> 10,
 359                initsize >> 10,
 360                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 361 }
 362
 363 #ifdef CONFIG_BLK_DEV_INITRD
 364 void free_initrd_mem(unsigned long start, unsigned long end)
 365 {
 366         if (start < end)
 367                 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
 368                        (end - start) >> 10);
 369
 370         for (; start < end; start += PAGE_SIZE) {
 371                 ClearPageReserved(virt_to_page(start));
 372                 set_page_count(virt_to_page(start), 1);
 373                 free_page(start);
 374                 totalram_pages++;
 375         }
 376 }
 377 #endif
 378
 379 extern char __init_begin, __init_end;
 380 extern void prom_free_prom_memory(void) __init;
 381
 382 void free_initmem(void)
 383 {
 384         unsigned long addr;
 385
 386         prom_free_prom_memory ();
 387
 388         addr = (unsigned long) &__init_begin;
 389         while (addr < (unsigned long) &__init_end) {
 390                 ClearPageReserved(virt_to_page(addr));
 391                 set_page_count(virt_to_page(addr), 1);
 392                 free_page(addr);
 393                 totalram_pages++;
 394                 addr += PAGE_SIZE;
 395         }
 396         printk(KERN_INFO "Freeing unused kernel memory: %dk freed\n",
 397                (&__init_end - &__init_begin) >> 10);
 398 }
 399
 400 void si_meminfo(struct sysinfo *val)
 401 {
 402         val->totalram = totalram_pages;
 403         val->sharedram = 0;
 404         val->freeram = nr_free_pages();
 405         val->bufferram = atomic_read(&buffermem_pages);
 406         val->totalhigh = totalhigh_pages;
 407         val->freehigh = nr_free_highpages();
 408         val->mem_unit = PAGE_SIZE;
 409
 410         return;
 411 }