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
  28 #include <asm/bootinfo.h>
  29 #include <asm/cachectl.h>
  30 #include <asm/cpu.h>
  31 #include <asm/dma.h>
  32 #include <asm/mmu_context.h>
  33 #include <asm/sections.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/pgalloc.h>
  36 #include <asm/tlb.h>
  37
  38 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  39
  40 unsigned long highstart_pfn, highend_pfn;
  41
  42 /*
  43  * We have up to 8 empty zeroed pages so we can map one of the right colour
  44  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  45  * where we have to avoid VCED / VECI exceptions for good performance at
  46  * any price.  Since page is never written to after the initialization we
  47  * don't have to care about aliases on other CPUs.
  48  */
  49 unsigned long empty_zero_page, zero_page_mask;
  50
  51 /*
  52  * Not static inline because used by IP27 special magic initialization code
  53  */
  54 unsigned long setup_zero_pages(void)
  55 {
  56         unsigned long order, size;
  57         struct page *page;
  58
  59         if (cpu_has_vce)
  60                 order = 3;
  61         else
  62                 order = 0;
  63
  64         empty_zero_page = __get_free_pages(GFP_KERNEL, order);
  65         if (!empty_zero_page)
  66                 panic("Oh boy, that early out of memory?");
  67
  68         page = virt_to_page(empty_zero_page);
  69         while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
  70                 set_bit(PG_reserved, &page->flags);
  71                 set_page_count(page, 0);
  72                 page++;
  73         }
  74
  75         size = PAGE_SIZE << order;
  76         zero_page_mask = (size - 1) & PAGE_MASK;
  77         memset((void *)empty_zero_page, 0, size);
  78
  79         return 1UL << order;
  80 }
  81
  82 #ifdef CONFIG_HIGHMEM
  83 pte_t *kmap_pte;
  84 pgprot_t kmap_prot;
  85
  86 EXPORT_SYMBOL(kmap_prot);
  87 EXPORT_SYMBOL(kmap_pte);
  88
  89 #define kmap_get_fixmap_pte(vaddr)                                      \
  90         pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
  91
  92 static void __init kmap_init(void)
  93 {
  94         unsigned long kmap_vstart;
  95
  96         /* cache the first kmap pte */
  97         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
  98         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
  99
 100         kmap_prot = PAGE_KERNEL;
 101 }
 102
 103 #ifdef CONFIG_MIPS64
 104 static void __init fixrange_init(unsigned long start, unsigned long end,
 105         pgd_t *pgd_base)
 106 {
 107         pgd_t *pgd;
 108         pmd_t *pmd;
 109         pte_t *pte;
 110         int i, j;
 111         unsigned long vaddr;
 112
 113         vaddr = start;
 114         i = __pgd_offset(vaddr);
 115         j = __pmd_offset(vaddr);
 116         pgd = pgd_base + i;
 117
 118         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 119                 pmd = (pmd_t *)pgd;
 120                 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
 121                         if (pmd_none(*pmd)) {
 122                                 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 123                                 set_pmd(pmd, __pmd(pte));
 124                                 if (pte != pte_offset_kernel(pmd, 0))
 125                                         BUG();
 126                         }
 127                         vaddr += PMD_SIZE;
 128                 }
 129                 j = 0;
 130         }
 131 }
 132 #endif /* CONFIG_MIPS64 */
 133 #endif /* CONFIG_HIGHMEM */
 134
 135 #ifndef CONFIG_DISCONTIGMEM
 136 extern void pagetable_init(void);
 137
 138 void __init paging_init(void)
 139 {
 140         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 141         unsigned long max_dma, high, low;
 142
 143         pagetable_init();
 144
 145 #ifdef CONFIG_HIGHMEM
 146         kmap_init();
 147 #endif
 148
 149         max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 150         low = max_low_pfn;
 151         high = highend_pfn;
 152
 153 #ifdef CONFIG_ISA
 154         if (low < max_dma)
 155                 zones_size[ZONE_DMA] = low;
 156         else {
 157                 zones_size[ZONE_DMA] = max_dma;
 158                 zones_size[ZONE_NORMAL] = low - max_dma;
 159         }
 160 #else
 161         zones_size[ZONE_DMA] = low;
 162 #endif
 163 #ifdef CONFIG_HIGHMEM
 164         if (cpu_has_dc_aliases) {
 165                 printk(KERN_WARNING "This processor doesn't support highmem.");
 166                 if (high - low)
 167                         printk(" %ldk highmem ignored", high - low);
 168                 printk("\n");
 169         } else
 170                 zones_size[ZONE_HIGHMEM] = high - low;
 171 #endif
 172
 173         free_area_init(zones_size);
 174 }
 175
 176 #define PFN_UP(x)       (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
 177 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
 178
 179 static inline int page_is_ram(unsigned long pagenr)
 180 {
 181         int i;
 182
 183         for (i = 0; i < boot_mem_map.nr_map; i++) {
 184                 unsigned long addr, end;
 185
 186                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 187                         /* not usable memory */
 188                         continue;
 189
 190                 addr = PFN_UP(boot_mem_map.map[i].addr);
 191                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 192                                boot_mem_map.map[i].size);
 193
 194                 if (pagenr >= addr && pagenr < end)
 195                         return 1;
 196         }
 197
 198         return 0;
 199 }
 200
 201 void __init mem_init(void)
 202 {
 203         unsigned long codesize, reservedpages, datasize, initsize;
 204         unsigned long tmp, ram;
 205
 206 #ifdef CONFIG_HIGHMEM
 207         highmem_start_page = mem_map + highstart_pfn;
 208 #ifdef CONFIG_DISCONTIGMEM
 209 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 210 #endif
 211         max_mapnr = num_physpages = highend_pfn;
 212 #else
 213         max_mapnr = num_physpages = max_low_pfn;
 214 #endif
 215         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 216
 217         totalram_pages += free_all_bootmem();
 218         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 219
 220         reservedpages = ram = 0;
 221         for (tmp = 0; tmp < max_low_pfn; tmp++)
 222                 if (page_is_ram(tmp)) {
 223                         ram++;
 224                         if (PageReserved(mem_map+tmp))
 225                                 reservedpages++;
 226                 }
 227
 228 #ifdef CONFIG_HIGHMEM
 229         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 230                 struct page *page = mem_map + tmp;
 231
 232                 if (!page_is_ram(tmp)) {
 233                         SetPageReserved(page);
 234                         continue;
 235                 }
 236                 ClearPageReserved(page);
 237 #ifdef CONFIG_LIMITED_DMA
 238                 set_page_address(page, lowmem_page_address(page));
 239 #endif
 240                 set_bit(PG_highmem, &page->flags);
 241                 set_page_count(page, 1);
 242                 __free_page(page);
 243                 totalhigh_pages++;
 244         }
 245         totalram_pages += totalhigh_pages;
 246 #endif
 247
 248         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 249         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 250         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 251
 252         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 253                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 254                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 255                ram << (PAGE_SHIFT-10),
 256                codesize >> 10,
 257                reservedpages << (PAGE_SHIFT-10),
 258                datasize >> 10,
 259                initsize >> 10,
 260                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 261 }
 262 #endif /* !CONFIG_DISCONTIGMEM */
 263
 264 #ifdef CONFIG_BLK_DEV_INITRD
 265 void free_initrd_mem(unsigned long start, unsigned long end)
 266 {
 267 #ifdef CONFIG_MIPS64
 268         /* Switch from KSEG0 to XKPHYS addresses */
 269         start = (unsigned long)phys_to_virt(CPHYSADDR(start));
 270         end = (unsigned long)phys_to_virt(CPHYSADDR(end));
 271 #endif
 272         if (start < end)
 273                 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
 274                        (end - start) >> 10);
 275
 276         for (; start < end; start += PAGE_SIZE) {
 277                 ClearPageReserved(virt_to_page(start));
 278                 set_page_count(virt_to_page(start), 1);
 279                 free_page(start);
 280                 totalram_pages++;
 281         }
 282 }
 283 #endif
 284
 285 extern unsigned long prom_free_prom_memory(void);
 286
 287 void free_initmem(void)
 288 {
 289         unsigned long addr, page, freed;
 290
 291         freed = prom_free_prom_memory();
 292
 293         addr = (unsigned long) &__init_begin;
 294         while (addr < (unsigned long) &__init_end) {
 295 #ifdef CONFIG_MIPS64
 296                 page = PAGE_OFFSET | CPHYSADDR(addr);
 297 #else
 298                 page = addr;
 299 #endif
 300                 ClearPageReserved(virt_to_page(page));
 301                 set_page_count(virt_to_page(page), 1);
 302                 free_page(page);
 303                 totalram_pages++;
 304                 freed += PAGE_SIZE;
 305                 addr += PAGE_SIZE;
 306         }
 307         printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
 308                freed >> 10);
 309 }