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 | __GFP_ZERO, 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
  78         return 1UL << order;
  79 }
  80
  81 #ifdef CONFIG_HIGHMEM
  82 pte_t *kmap_pte;
  83 pgprot_t kmap_prot;
  84
  85 #define kmap_get_fixmap_pte(vaddr)                                      \
  86         pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
  87
  88 static void __init kmap_init(void)
  89 {
  90         unsigned long kmap_vstart;
  91
  92         /* cache the first kmap pte */
  93         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
  94         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
  95
  96         kmap_prot = PAGE_KERNEL;
  97 }
  98
  99 #ifdef CONFIG_MIPS64
 100 static void __init fixrange_init(unsigned long start, unsigned long end,
 101         pgd_t *pgd_base)
 102 {
 103         pgd_t *pgd;
 104         pmd_t *pmd;
 105         pte_t *pte;
 106         int i, j;
 107         unsigned long vaddr;
 108
 109         vaddr = start;
 110         i = __pgd_offset(vaddr);
 111         j = __pmd_offset(vaddr);
 112         pgd = pgd_base + i;
 113
 114         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 115                 pmd = (pmd_t *)pgd;
 116                 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
 117                         if (pmd_none(*pmd)) {
 118                                 pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 119                                 set_pmd(pmd, __pmd(pte));
 120                                 if (pte != pte_offset_kernel(pmd, 0))
 121                                         BUG();
 122                         }
 123                         vaddr += PMD_SIZE;
 124                 }
 125                 j = 0;
 126         }
 127 }
 128 #endif /* CONFIG_MIPS64 */
 129 #endif /* CONFIG_HIGHMEM */
 130
 131 #ifndef CONFIG_DISCONTIGMEM
 132 extern void pagetable_init(void);
 133
 134 void __init paging_init(void)
 135 {
 136         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 137         unsigned long max_dma, high, low;
 138
 139         pagetable_init();
 140
 141 #ifdef CONFIG_HIGHMEM
 142         kmap_init();
 143 #endif
 144
 145         max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 146         low = max_low_pfn;
 147         high = highend_pfn;
 148
 149 #ifdef CONFIG_ISA
 150         if (low < max_dma)
 151                 zones_size[ZONE_DMA] = low;
 152         else {
 153                 zones_size[ZONE_DMA] = max_dma;
 154                 zones_size[ZONE_NORMAL] = low - max_dma;
 155         }
 156 #else
 157         zones_size[ZONE_DMA] = low;
 158 #endif
 159 #ifdef CONFIG_HIGHMEM
 160         if (cpu_has_dc_aliases) {
 161                 printk(KERN_WARNING "This processor doesn't support highmem.");
 162                 if (high - low)
 163                         printk(" %ldk highmem ignored", high - low);
 164                 printk("\n");
 165         } else
 166                 zones_size[ZONE_HIGHMEM] = high - low;
 167 #endif
 168
 169         free_area_init(zones_size);
 170 }
 171
 172 #define PFN_UP(x)       (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
 173 #define PFN_DOWN(x)     ((x) >> PAGE_SHIFT)
 174
 175 static inline int page_is_ram(unsigned long pagenr)
 176 {
 177         int i;
 178
 179         for (i = 0; i < boot_mem_map.nr_map; i++) {
 180                 unsigned long addr, end;
 181
 182                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 183                         /* not usable memory */
 184                         continue;
 185
 186                 addr = PFN_UP(boot_mem_map.map[i].addr);
 187                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 188                                boot_mem_map.map[i].size);
 189
 190                 if (pagenr >= addr && pagenr < end)
 191                         return 1;
 192         }
 193
 194         return 0;
 195 }
 196
 197 void __init mem_init(void)
 198 {
 199         unsigned long codesize, reservedpages, datasize, initsize;
 200         unsigned long tmp, ram;
 201
 202 #ifdef CONFIG_HIGHMEM
 203 #ifdef CONFIG_DISCONTIGMEM
 204 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 205 #endif
 206         max_mapnr = num_physpages = highend_pfn;
 207 #else
 208         max_mapnr = num_physpages = max_low_pfn;
 209 #endif
 210         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 211
 212         totalram_pages += free_all_bootmem();
 213         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 214
 215         reservedpages = ram = 0;
 216         for (tmp = 0; tmp < max_low_pfn; tmp++)
 217                 if (page_is_ram(tmp)) {
 218                         ram++;
 219                         if (PageReserved(mem_map+tmp))
 220                                 reservedpages++;
 221                 }
 222
 223 #ifdef CONFIG_HIGHMEM
 224         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 225                 struct page *page = mem_map + tmp;
 226
 227                 if (!page_is_ram(tmp)) {
 228                         SetPageReserved(page);
 229                         continue;
 230                 }
 231                 ClearPageReserved(page);
 232 #ifdef CONFIG_LIMITED_DMA
 233                 set_page_address(page, lowmem_page_address(page));
 234 #endif
 235                 set_bit(PG_highmem, &page->flags);
 236                 set_page_count(page, 1);
 237                 __free_page(page);
 238                 totalhigh_pages++;
 239         }
 240         totalram_pages += totalhigh_pages;
 241 #endif
 242
 243         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 244         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 245         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 246
 247         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 248                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 249                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 250                ram << (PAGE_SHIFT-10),
 251                codesize >> 10,
 252                reservedpages << (PAGE_SHIFT-10),
 253                datasize >> 10,
 254                initsize >> 10,
 255                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 256 }
 257 #endif /* !CONFIG_DISCONTIGMEM */
 258
 259 #ifdef CONFIG_BLK_DEV_INITRD
 260 void free_initrd_mem(unsigned long start, unsigned long end)
 261 {
 262 #ifdef CONFIG_MIPS64
 263         /* Switch from KSEG0 to XKPHYS addresses */
 264         start = (unsigned long)phys_to_virt(CPHYSADDR(start));
 265         end = (unsigned long)phys_to_virt(CPHYSADDR(end));
 266 #endif
 267         if (start < end)
 268                 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
 269                        (end - start) >> 10);
 270
 271         for (; start < end; start += PAGE_SIZE) {
 272                 ClearPageReserved(virt_to_page(start));
 273                 set_page_count(virt_to_page(start), 1);
 274                 free_page(start);
 275                 totalram_pages++;
 276         }
 277 }
 278 #endif
 279
 280 extern unsigned long prom_free_prom_memory(void);
 281
 282 void free_initmem(void)
 283 {
 284         unsigned long addr, page, freed;
 285
 286         freed = prom_free_prom_memory();
 287
 288         addr = (unsigned long) &__init_begin;
 289         while (addr < (unsigned long) &__init_end) {
 290 #ifdef CONFIG_MIPS64
 291                 page = PAGE_OFFSET | CPHYSADDR(addr);
 292 #else
 293                 page = addr;
 294 #endif
 295                 ClearPageReserved(virt_to_page(page));
 296                 set_page_count(virt_to_page(page), 1);
 297                 free_page(page);
 298                 totalram_pages++;
 299                 freed += PAGE_SIZE;
 300                 addr += PAGE_SIZE;
 301         }
 302         printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
 303                freed >> 10);
 304 }