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/bug.h>
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/signal.h>
  15 #include <linux/sched.h>
  16 #include <linux/smp.h>
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/string.h>
  20 #include <linux/types.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/mman.h>
  24 #include <linux/mm.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/highmem.h>
  27 #include <linux/swap.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/pfn.h>
  30 #include <linux/hardirq.h>
  31 #include <linux/gfp.h>
  32 #include <linux/kcore.h>
  33
  34 #include <asm/asm-offsets.h>
  35 #include <asm/bootinfo.h>
  36 #include <asm/cachectl.h>
  37 #include <asm/cpu.h>
  38 #include <asm/dma.h>
  39 #include <asm/kmap_types.h>
  40 #include <asm/mmu_context.h>
  41 #include <asm/sections.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/pgalloc.h>
  44 #include <asm/tlb.h>
  45 #include <asm/fixmap.h>
  46
  47 /*
  48  * We have up to 8 empty zeroed pages so we can map one of the right colour
  49  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  50  * where we have to avoid VCED / VECI exceptions for good performance at
  51  * any price.  Since page is never written to after the initialization we
  52  * don't have to care about aliases on other CPUs.
  53  */
  54 unsigned long empty_zero_page, zero_page_mask;
  55 EXPORT_SYMBOL_GPL(empty_zero_page);
  56
  57 /*
  58  * Not static inline because used by IP27 special magic initialization code
  59  */
  60 void setup_zero_pages(void)
  61 {
  62         unsigned int order, i;
  63         struct page *page;
  64
  65         if (cpu_has_vce)
  66                 order = 3;
  67         else
  68                 order = 0;
  69
  70         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  71         if (!empty_zero_page)
  72                 panic("Oh boy, that early out of memory?");
  73
  74         page = virt_to_page((void *)empty_zero_page);
  75         split_page(page, order);
  76         for (i = 0; i < (1 << order); i++, page++)
  77                 mark_page_reserved(page);
  78
  79         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  80 }
  81
  82 void *kmap_coherent(struct page *page, unsigned long addr)
  83 {
  84         enum fixed_addresses idx;
  85         unsigned long vaddr, flags, entrylo;
  86         unsigned long old_ctx;
  87         pte_t pte;
  88         int tlbidx;
  89
  90         BUG_ON(Page_dcache_dirty(page));
  91
  92         pagefault_disable();
  93         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
  94         idx += in_interrupt() ? FIX_N_COLOURS : 0;
  95         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
  96         pte = mk_pte(page, PAGE_KERNEL);
  97 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
  98         entrylo = pte.pte_high;
  99 #else
 100         entrylo = pte_to_entrylo(pte_val(pte));
 101 #endif
 102
 103         local_irq_save(flags);
 104         old_ctx = read_c0_entryhi();
 105         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 106         write_c0_entrylo0(entrylo);
 107         write_c0_entrylo1(entrylo);
 108         tlbidx = read_c0_wired();
 109         write_c0_wired(tlbidx + 1);
 110         write_c0_index(tlbidx);
 111         mtc0_tlbw_hazard();
 112         tlb_write_indexed();
 113         tlbw_use_hazard();
 114         write_c0_entryhi(old_ctx);
 115         local_irq_restore(flags);
 116
 117         return (void*) vaddr;
 118 }
 119
 120 void kunmap_coherent(void)
 121 {
 122         unsigned int wired;
 123         unsigned long flags, old_ctx;
 124
 125         local_irq_save(flags);
 126         old_ctx = read_c0_entryhi();
 127         wired = read_c0_wired() - 1;
 128         write_c0_wired(wired);
 129         write_c0_index(wired);
 130         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 131         write_c0_entrylo0(0);
 132         write_c0_entrylo1(0);
 133         mtc0_tlbw_hazard();
 134         tlb_write_indexed();
 135         tlbw_use_hazard();
 136         write_c0_entryhi(old_ctx);
 137         local_irq_restore(flags);
 138         pagefault_enable();
 139 }
 140
 141 void copy_user_highpage(struct page *to, struct page *from,
 142         unsigned long vaddr, struct vm_area_struct *vma)
 143 {
 144         void *vfrom, *vto;
 145
 146         vto = kmap_atomic(to);
 147         if (cpu_has_dc_aliases &&
 148             page_mapped(from) && !Page_dcache_dirty(from)) {
 149                 vfrom = kmap_coherent(from, vaddr);
 150                 copy_page(vto, vfrom);
 151                 kunmap_coherent();
 152         } else {
 153                 vfrom = kmap_atomic(from);
 154                 copy_page(vto, vfrom);
 155                 kunmap_atomic(vfrom);
 156         }
 157         if ((!cpu_has_ic_fills_f_dc) ||
 158             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 159                 flush_data_cache_page((unsigned long)vto);
 160         kunmap_atomic(vto);
 161         /* Make sure this page is cleared on other CPU's too before using it */
 162         smp_wmb();
 163 }
 164
 165 void copy_to_user_page(struct vm_area_struct *vma,
 166         struct page *page, unsigned long vaddr, void *dst, const void *src,
 167         unsigned long len)
 168 {
 169         if (cpu_has_dc_aliases &&
 170             page_mapped(page) && !Page_dcache_dirty(page)) {
 171                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 172                 memcpy(vto, src, len);
 173                 kunmap_coherent();
 174         } else {
 175                 memcpy(dst, src, len);
 176                 if (cpu_has_dc_aliases)
 177                         SetPageDcacheDirty(page);
 178         }
 179         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 180                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 181 }
 182
 183 void copy_from_user_page(struct vm_area_struct *vma,
 184         struct page *page, unsigned long vaddr, void *dst, const void *src,
 185         unsigned long len)
 186 {
 187         if (cpu_has_dc_aliases &&
 188             page_mapped(page) && !Page_dcache_dirty(page)) {
 189                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 190                 memcpy(dst, vfrom, len);
 191                 kunmap_coherent();
 192         } else {
 193                 memcpy(dst, src, len);
 194                 if (cpu_has_dc_aliases)
 195                         SetPageDcacheDirty(page);
 196         }
 197 }
 198 EXPORT_SYMBOL_GPL(copy_from_user_page);
 199
 200 void __init fixrange_init(unsigned long start, unsigned long end,
 201         pgd_t *pgd_base)
 202 {
 203 #ifdef CONFIG_HIGHMEM
 204         pgd_t *pgd;
 205         pud_t *pud;
 206         pmd_t *pmd;
 207         pte_t *pte;
 208         int i, j, k;
 209         unsigned long vaddr;
 210
 211         vaddr = start;
 212         i = __pgd_offset(vaddr);
 213         j = __pud_offset(vaddr);
 214         k = __pmd_offset(vaddr);
 215         pgd = pgd_base + i;
 216
 217         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 218                 pud = (pud_t *)pgd;
 219                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 220                         pmd = (pmd_t *)pud;
 221                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 222                                 if (pmd_none(*pmd)) {
 223                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 224                                         set_pmd(pmd, __pmd((unsigned long)pte));
 225                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 226                                 }
 227                                 vaddr += PMD_SIZE;
 228                         }
 229                         k = 0;
 230                 }
 231                 j = 0;
 232         }
 233 #endif
 234 }
 235
 236 #ifndef CONFIG_NEED_MULTIPLE_NODES
 237 int page_is_ram(unsigned long pagenr)
 238 {
 239         int i;
 240
 241         for (i = 0; i < boot_mem_map.nr_map; i++) {
 242                 unsigned long addr, end;
 243
 244                 switch (boot_mem_map.map[i].type) {
 245                 case BOOT_MEM_RAM:
 246                 case BOOT_MEM_INIT_RAM:
 247                         break;
 248                 default:
 249                         /* not usable memory */
 250                         continue;
 251                 }
 252
 253                 addr = PFN_UP(boot_mem_map.map[i].addr);
 254                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 255                                boot_mem_map.map[i].size);
 256
 257                 if (pagenr >= addr && pagenr < end)
 258                         return 1;
 259         }
 260
 261         return 0;
 262 }
 263
 264 void __init paging_init(void)
 265 {
 266         unsigned long max_zone_pfns[MAX_NR_ZONES];
 267         unsigned long lastpfn __maybe_unused;
 268
 269         pagetable_init();
 270
 271 #ifdef CONFIG_HIGHMEM
 272         kmap_init();
 273 #endif
 274 #ifdef CONFIG_ZONE_DMA
 275         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 276 #endif
 277 #ifdef CONFIG_ZONE_DMA32
 278         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 279 #endif
 280         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 281         lastpfn = max_low_pfn;
 282 #ifdef CONFIG_HIGHMEM
 283         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 284         lastpfn = highend_pfn;
 285
 286         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 287                 printk(KERN_WARNING "This processor doesn't support highmem."
 288                        " %ldk highmem ignored\n",
 289                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 290                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 291                 lastpfn = max_low_pfn;
 292         }
 293 #endif
 294
 295         free_area_init_nodes(max_zone_pfns);
 296 }
 297
 298 #ifdef CONFIG_64BIT
 299 static struct kcore_list kcore_kseg0;
 300 #endif
 301
 302 static inline void mem_init_free_highmem(void)
 303 {
 304 #ifdef CONFIG_HIGHMEM
 305         unsigned long tmp;
 306
 307         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 308                 struct page *page = pfn_to_page(tmp);
 309
 310                 if (!page_is_ram(tmp))
 311                         SetPageReserved(page);
 312                 else
 313                         free_highmem_page(page);
 314         }
 315 #endif
 316 }
 317
 318 void __init mem_init(void)
 319 {
 320 #ifdef CONFIG_HIGHMEM
 321 #ifdef CONFIG_DISCONTIGMEM
 322 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 323 #endif
 324         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 325 #else
 326         max_mapnr = max_low_pfn;
 327 #endif
 328         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 329
 330         free_all_bootmem();
 331         setup_zero_pages();     /* Setup zeroed pages.  */
 332         mem_init_free_highmem();
 333         mem_init_print_info(NULL);
 334
 335 #ifdef CONFIG_64BIT
 336         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 337                 /* The -4 is a hack so that user tools don't have to handle
 338                    the overflow.  */
 339                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 340                                 0x80000000 - 4, KCORE_TEXT);
 341 #endif
 342 }
 343 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 344
 345 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 346 {
 347         unsigned long pfn;
 348
 349         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 350                 struct page *page = pfn_to_page(pfn);
 351                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 352
 353                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 354                 free_reserved_page(page);
 355         }
 356         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 357 }
 358
 359 #ifdef CONFIG_BLK_DEV_INITRD
 360 void free_initrd_mem(unsigned long start, unsigned long end)
 361 {
 362         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 363                            "initrd");
 364 }
 365 #endif
 366
 367 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 368
 369 void __init_refok free_initmem(void)
 370 {
 371         prom_free_prom_memory();
 372         /*
 373          * Let the platform define a specific function to free the
 374          * init section since EVA may have used any possible mapping
 375          * between virtual and physical addresses.
 376          */
 377         if (free_init_pages_eva)
 378                 free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
 379         else
 380                 free_initmem_default(POISON_FREE_INITMEM);
 381 }
 382
 383 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 384 unsigned long pgd_current[NR_CPUS];
 385 #endif
 386
 387 /*
 388  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 389  * are constants.  So we use the variants from asm-offset.h until that gcc
 390  * will officially be retired.
 391  *
 392  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 393  * with a single LUI instruction in the TLB handlers.  If we used
 394  * __aligned(64K), its size would get rounded up to the alignment
 395  * size, and waste space.  So we place it in its own section and align
 396  * it in the linker script.
 397  */
 398 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 399 #ifndef __PAGETABLE_PMD_FOLDED
 400 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 401 #endif
 402 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;