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 Ralf Baechle
   7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
   9  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
  10  */
  11 #include <linux/config.h>
  12 #include <linux/init.h>
  13 #include <linux/module.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/proc_fs.h>
  28
  29 #include <asm/bootinfo.h>
  30 #include <asm/cachectl.h>
  31 #include <asm/cpu.h>
  32 #include <asm/dma.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/sections.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/pgalloc.h>
  37 #include <asm/tlb.h>
  38
  39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  40
  41 unsigned long highstart_pfn, highend_pfn;
  42
  43 /*
  44  * We have up to 8 empty zeroed pages so we can map one of the right colour
  45  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  46  * where we have to avoid VCED / VECI exceptions for good performance at
  47  * any price.  Since page is never written to after the initialization we
  48  * don't have to care about aliases on other CPUs.
  49  */
  50 unsigned long empty_zero_page, zero_page_mask;
  51
  52 /*
  53  * Not static inline because used by IP27 special magic initialization code
  54  */
  55 unsigned long setup_zero_pages(void)
  56 {
  57         unsigned int order;
  58         unsigned long size;
  59         struct page *page;
  60
  61         if (cpu_has_vce)
  62                 order = 3;
  63         else
  64                 order = 0;
  65
  66         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  67         if (!empty_zero_page)
  68                 panic("Oh boy, that early out of memory?");
  69
  70         page = virt_to_page(empty_zero_page);
  71         split_page(page, order);
  72         while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
  73                 SetPageReserved(page);
  74                 page++;
  75         }
  76
  77         size = PAGE_SIZE << order;
  78         zero_page_mask = (size - 1) & PAGE_MASK;
  79
  80         return 1UL << order;
  81 }
  82
  83 #ifdef CONFIG_HIGHMEM
  84 pte_t *kmap_pte;
  85 pgprot_t kmap_prot;
  86
  87 #define kmap_get_fixmap_pte(vaddr)                                      \
  88         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
  89
  90 static void __init kmap_init(void)
  91 {
  92         unsigned long kmap_vstart;
  93
  94         /* cache the first kmap pte */
  95         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
  96         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
  97
  98         kmap_prot = PAGE_KERNEL;
  99 }
 100
 101 #ifdef CONFIG_32BIT
 102 void __init fixrange_init(unsigned long start, unsigned long end,
 103         pgd_t *pgd_base)
 104 {
 105         pgd_t *pgd;
 106         pud_t *pud;
 107         pmd_t *pmd;
 108         pte_t *pte;
 109         int i, j, k;
 110         unsigned long vaddr;
 111
 112         vaddr = start;
 113         i = __pgd_offset(vaddr);
 114         j = __pud_offset(vaddr);
 115         k = __pmd_offset(vaddr);
 116         pgd = pgd_base + i;
 117
 118         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 119                 pud = (pud_t *)pgd;
 120                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 121                         pmd = (pmd_t *)pud;
 122                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 123                                 if (pmd_none(*pmd)) {
 124                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 125                                         set_pmd(pmd, __pmd(pte));
 126                                         if (pte != pte_offset_kernel(pmd, 0))
 127                                                 BUG();
 128                                 }
 129                                 vaddr += PMD_SIZE;
 130                         }
 131                         k = 0;
 132                 }
 133                 j = 0;
 134         }
 135 }
 136 #endif /* CONFIG_32BIT */
 137 #endif /* CONFIG_HIGHMEM */
 138
 139 #ifndef CONFIG_NEED_MULTIPLE_NODES
 140 extern void pagetable_init(void);
 141
 142 void __init paging_init(void)
 143 {
 144         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 145         unsigned long max_dma, high, low;
 146
 147         pagetable_init();
 148
 149 #ifdef CONFIG_HIGHMEM
 150         kmap_init();
 151 #endif
 152
 153         max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 154         low = max_low_pfn;
 155         high = highend_pfn;
 156
 157 #ifdef CONFIG_ISA
 158         if (low < max_dma)
 159                 zones_size[ZONE_DMA] = low;
 160         else {
 161                 zones_size[ZONE_DMA] = max_dma;
 162                 zones_size[ZONE_NORMAL] = low - max_dma;
 163         }
 164 #else
 165         zones_size[ZONE_DMA] = low;
 166 #endif
 167 #ifdef CONFIG_HIGHMEM
 168         if (cpu_has_dc_aliases) {
 169                 printk(KERN_WARNING "This processor doesn't support highmem.");
 170                 if (high - low)
 171                         printk(" %ldk highmem ignored", high - low);
 172                 printk("\n");
 173         } else
 174                 zones_size[ZONE_HIGHMEM] = high - low;
 175 #endif
 176
 177         free_area_init(zones_size);
 178 }
 179
 180 #define PFN_UP(x)       (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
 181 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
 182
 183 static inline int page_is_ram(unsigned long pagenr)
 184 {
 185         int i;
 186
 187         for (i = 0; i < boot_mem_map.nr_map; i++) {
 188                 unsigned long addr, end;
 189
 190                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 191                         /* not usable memory */
 192                         continue;
 193
 194                 addr = PFN_UP(boot_mem_map.map[i].addr);
 195                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 196                                boot_mem_map.map[i].size);
 197
 198                 if (pagenr >= addr && pagenr < end)
 199                         return 1;
 200         }
 201
 202         return 0;
 203 }
 204
 205 static struct kcore_list kcore_mem, kcore_vmalloc;
 206 #ifdef CONFIG_64BIT
 207 static struct kcore_list kcore_kseg0;
 208 #endif
 209
 210 void __init mem_init(void)
 211 {
 212         unsigned long codesize, reservedpages, datasize, initsize;
 213         unsigned long tmp, ram;
 214
 215 #ifdef CONFIG_HIGHMEM
 216 #ifdef CONFIG_DISCONTIGMEM
 217 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 218 #endif
 219         max_mapnr = num_physpages = highend_pfn;
 220 #else
 221         max_mapnr = num_physpages = max_low_pfn;
 222 #endif
 223         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 224
 225         totalram_pages += free_all_bootmem();
 226         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 227
 228         reservedpages = ram = 0;
 229         for (tmp = 0; tmp < max_low_pfn; tmp++)
 230                 if (page_is_ram(tmp)) {
 231                         ram++;
 232                         if (PageReserved(mem_map+tmp))
 233                                 reservedpages++;
 234                 }
 235
 236 #ifdef CONFIG_HIGHMEM
 237         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 238                 struct page *page = mem_map + tmp;
 239
 240                 if (!page_is_ram(tmp)) {
 241                         SetPageReserved(page);
 242                         continue;
 243                 }
 244                 ClearPageReserved(page);
 245 #ifdef CONFIG_LIMITED_DMA
 246                 set_page_address(page, lowmem_page_address(page));
 247 #endif
 248                 init_page_count(page);
 249                 __free_page(page);
 250                 totalhigh_pages++;
 251         }
 252         totalram_pages += totalhigh_pages;
 253 #endif
 254
 255         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 256         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 257         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 258
 259 #ifdef CONFIG_64BIT
 260         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 261                 /* The -4 is a hack so that user tools don't have to handle
 262                    the overflow.  */
 263                 kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
 264 #endif
 265         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 266         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 267                    VMALLOC_END-VMALLOC_START);
 268
 269         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 270                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 271                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 272                ram << (PAGE_SHIFT-10),
 273                codesize >> 10,
 274                reservedpages << (PAGE_SHIFT-10),
 275                datasize >> 10,
 276                initsize >> 10,
 277                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 278 }
 279 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 280
 281 #ifdef CONFIG_BLK_DEV_INITRD
 282 void free_initrd_mem(unsigned long start, unsigned long end)
 283 {
 284 #ifdef CONFIG_64BIT
 285         /* Switch from KSEG0 to XKPHYS addresses */
 286         start = (unsigned long)phys_to_virt(CPHYSADDR(start));
 287         end = (unsigned long)phys_to_virt(CPHYSADDR(end));
 288 #endif
 289         if (start < end)
 290                 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
 291                        (end - start) >> 10);
 292
 293         for (; start < end; start += PAGE_SIZE) {
 294                 ClearPageReserved(virt_to_page(start));
 295                 init_page_count(virt_to_page(start));
 296                 free_page(start);
 297                 totalram_pages++;
 298         }
 299 }
 300 #endif
 301
 302 extern unsigned long prom_free_prom_memory(void);
 303
 304 void free_initmem(void)
 305 {
 306         unsigned long addr, page, freed;
 307
 308         freed = prom_free_prom_memory();
 309
 310         addr = (unsigned long) &__init_begin;
 311         while (addr < (unsigned long) &__init_end) {
 312 #ifdef CONFIG_64BIT
 313                 page = PAGE_OFFSET | CPHYSADDR(addr);
 314 #else
 315                 page = addr;
 316 #endif
 317                 ClearPageReserved(virt_to_page(page));
 318                 init_page_count(virt_to_page(page));
 319                 free_page(page);
 320                 totalram_pages++;
 321                 freed += PAGE_SIZE;
 322                 addr += PAGE_SIZE;
 323         }
 324         printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
 325                freed >> 10);
 326 }