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 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
  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, prot);
  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 *kmap_coherent(struct page *page, unsigned long addr)
 121 {
 122         return __kmap_pgprot(page, addr, PAGE_KERNEL);
 123 }
 124
 125 void *kmap_noncoherent(struct page *page, unsigned long addr)
 126 {
 127         return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
 128 }
 129
 130 void kunmap_coherent(void)
 131 {
 132         unsigned int wired;
 133         unsigned long flags, old_ctx;
 134
 135         local_irq_save(flags);
 136         old_ctx = read_c0_entryhi();
 137         wired = read_c0_wired() - 1;
 138         write_c0_wired(wired);
 139         write_c0_index(wired);
 140         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 141         write_c0_entrylo0(0);
 142         write_c0_entrylo1(0);
 143         mtc0_tlbw_hazard();
 144         tlb_write_indexed();
 145         tlbw_use_hazard();
 146         write_c0_entryhi(old_ctx);
 147         local_irq_restore(flags);
 148         pagefault_enable();
 149 }
 150
 151 void copy_user_highpage(struct page *to, struct page *from,
 152         unsigned long vaddr, struct vm_area_struct *vma)
 153 {
 154         void *vfrom, *vto;
 155
 156         vto = kmap_atomic(to);
 157         if (cpu_has_dc_aliases &&
 158             page_mapped(from) && !Page_dcache_dirty(from)) {
 159                 vfrom = kmap_coherent(from, vaddr);
 160                 copy_page(vto, vfrom);
 161                 kunmap_coherent();
 162         } else {
 163                 vfrom = kmap_atomic(from);
 164                 copy_page(vto, vfrom);
 165                 kunmap_atomic(vfrom);
 166         }
 167         if ((!cpu_has_ic_fills_f_dc) ||
 168             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 169                 flush_data_cache_page((unsigned long)vto);
 170         kunmap_atomic(vto);
 171         /* Make sure this page is cleared on other CPU's too before using it */
 172         smp_wmb();
 173 }
 174
 175 void copy_to_user_page(struct vm_area_struct *vma,
 176         struct page *page, unsigned long vaddr, void *dst, const void *src,
 177         unsigned long len)
 178 {
 179         if (cpu_has_dc_aliases &&
 180             page_mapped(page) && !Page_dcache_dirty(page)) {
 181                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 182                 memcpy(vto, src, len);
 183                 kunmap_coherent();
 184         } else {
 185                 memcpy(dst, src, len);
 186                 if (cpu_has_dc_aliases)
 187                         SetPageDcacheDirty(page);
 188         }
 189         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 190                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 191 }
 192
 193 void copy_from_user_page(struct vm_area_struct *vma,
 194         struct page *page, unsigned long vaddr, void *dst, const void *src,
 195         unsigned long len)
 196 {
 197         if (cpu_has_dc_aliases &&
 198             page_mapped(page) && !Page_dcache_dirty(page)) {
 199                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 200                 memcpy(dst, vfrom, len);
 201                 kunmap_coherent();
 202         } else {
 203                 memcpy(dst, src, len);
 204                 if (cpu_has_dc_aliases)
 205                         SetPageDcacheDirty(page);
 206         }
 207 }
 208 EXPORT_SYMBOL_GPL(copy_from_user_page);
 209
 210 void __init fixrange_init(unsigned long start, unsigned long end,
 211         pgd_t *pgd_base)
 212 {
 213 #ifdef CONFIG_HIGHMEM
 214         pgd_t *pgd;
 215         pud_t *pud;
 216         pmd_t *pmd;
 217         pte_t *pte;
 218         int i, j, k;
 219         unsigned long vaddr;
 220
 221         vaddr = start;
 222         i = __pgd_offset(vaddr);
 223         j = __pud_offset(vaddr);
 224         k = __pmd_offset(vaddr);
 225         pgd = pgd_base + i;
 226
 227         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 228                 pud = (pud_t *)pgd;
 229                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 230                         pmd = (pmd_t *)pud;
 231                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 232                                 if (pmd_none(*pmd)) {
 233                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 234                                         set_pmd(pmd, __pmd((unsigned long)pte));
 235                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 236                                 }
 237                                 vaddr += PMD_SIZE;
 238                         }
 239                         k = 0;
 240                 }
 241                 j = 0;
 242         }
 243 #endif
 244 }
 245
 246 #ifndef CONFIG_NEED_MULTIPLE_NODES
 247 int page_is_ram(unsigned long pagenr)
 248 {
 249         int i;
 250
 251         for (i = 0; i < boot_mem_map.nr_map; i++) {
 252                 unsigned long addr, end;
 253
 254                 switch (boot_mem_map.map[i].type) {
 255                 case BOOT_MEM_RAM:
 256                 case BOOT_MEM_INIT_RAM:
 257                         break;
 258                 default:
 259                         /* not usable memory */
 260                         continue;
 261                 }
 262
 263                 addr = PFN_UP(boot_mem_map.map[i].addr);
 264                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 265                                boot_mem_map.map[i].size);
 266
 267                 if (pagenr >= addr && pagenr < end)
 268                         return 1;
 269         }
 270
 271         return 0;
 272 }
 273
 274 void __init paging_init(void)
 275 {
 276         unsigned long max_zone_pfns[MAX_NR_ZONES];
 277         unsigned long lastpfn __maybe_unused;
 278
 279         pagetable_init();
 280
 281 #ifdef CONFIG_HIGHMEM
 282         kmap_init();
 283 #endif
 284 #ifdef CONFIG_ZONE_DMA
 285         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 286 #endif
 287 #ifdef CONFIG_ZONE_DMA32
 288         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 289 #endif
 290         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 291         lastpfn = max_low_pfn;
 292 #ifdef CONFIG_HIGHMEM
 293         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 294         lastpfn = highend_pfn;
 295
 296         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 297                 printk(KERN_WARNING "This processor doesn't support highmem."
 298                        " %ldk highmem ignored\n",
 299                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 300                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 301                 lastpfn = max_low_pfn;
 302         }
 303 #endif
 304
 305         free_area_init_nodes(max_zone_pfns);
 306 }
 307
 308 #ifdef CONFIG_64BIT
 309 static struct kcore_list kcore_kseg0;
 310 #endif
 311
 312 static inline void mem_init_free_highmem(void)
 313 {
 314 #ifdef CONFIG_HIGHMEM
 315         unsigned long tmp;
 316
 317         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 318                 struct page *page = pfn_to_page(tmp);
 319
 320                 if (!page_is_ram(tmp))
 321                         SetPageReserved(page);
 322                 else
 323                         free_highmem_page(page);
 324         }
 325 #endif
 326 }
 327
 328 void __init mem_init(void)
 329 {
 330 #ifdef CONFIG_HIGHMEM
 331 #ifdef CONFIG_DISCONTIGMEM
 332 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 333 #endif
 334         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 335 #else
 336         max_mapnr = max_low_pfn;
 337 #endif
 338         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 339
 340         free_all_bootmem();
 341         setup_zero_pages();     /* Setup zeroed pages.  */
 342         mem_init_free_highmem();
 343         mem_init_print_info(NULL);
 344
 345 #ifdef CONFIG_64BIT
 346         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 347                 /* The -4 is a hack so that user tools don't have to handle
 348                    the overflow.  */
 349                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 350                                 0x80000000 - 4, KCORE_TEXT);
 351 #endif
 352 }
 353 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 354
 355 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 356 {
 357         unsigned long pfn;
 358
 359         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 360                 struct page *page = pfn_to_page(pfn);
 361                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 362
 363                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 364                 free_reserved_page(page);
 365         }
 366         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 367 }
 368
 369 #ifdef CONFIG_BLK_DEV_INITRD
 370 void free_initrd_mem(unsigned long start, unsigned long end)
 371 {
 372         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 373                            "initrd");
 374 }
 375 #endif
 376
 377 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 378
 379 void __init_refok free_initmem(void)
 380 {
 381         prom_free_prom_memory();
 382         /*
 383          * Let the platform define a specific function to free the
 384          * init section since EVA may have used any possible mapping
 385          * between virtual and physical addresses.
 386          */
 387         if (free_init_pages_eva)
 388                 free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
 389         else
 390                 free_initmem_default(POISON_FREE_INITMEM);
 391 }
 392
 393 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 394 unsigned long pgd_current[NR_CPUS];
 395 #endif
 396
 397 /*
 398  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 399  * are constants.  So we use the variants from asm-offset.h until that gcc
 400  * will officially be retired.
 401  *
 402  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 403  * with a single LUI instruction in the TLB handlers.  If we used
 404  * __aligned(64K), its size would get rounded up to the alignment
 405  * size, and waste space.  So we place it in its own section and align
 406  * it in the linker script.
 407  */
 408 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 409 #ifndef __PAGETABLE_PMD_FOLDED
 410 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 411 #endif
 412 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;