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 EXPORT_SYMBOL(zero_page_mask);
  57
  58 /*
  59  * Not static inline because used by IP27 special magic initialization code
  60  */
  61 void setup_zero_pages(void)
  62 {
  63         unsigned int order, i;
  64         struct page *page;
  65
  66         if (cpu_has_vce)
  67                 order = 3;
  68         else
  69                 order = 0;
  70
  71         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  72         if (!empty_zero_page)
  73                 panic("Oh boy, that early out of memory?");
  74
  75         page = virt_to_page((void *)empty_zero_page);
  76         split_page(page, order);
  77         for (i = 0; i < (1 << order); i++, page++)
  78                 mark_page_reserved(page);
  79
  80         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  81 }
  82
  83 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
  84 {
  85         enum fixed_addresses idx;
  86         unsigned long vaddr, flags, entrylo;
  87         unsigned long old_ctx;
  88         pte_t pte;
  89         int tlbidx;
  90
  91         BUG_ON(Page_dcache_dirty(page));
  92
  93         pagefault_disable();
  94         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
  95         idx += in_interrupt() ? FIX_N_COLOURS : 0;
  96         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
  97         pte = mk_pte(page, prot);
  98 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
  99         entrylo = pte.pte_high;
 100 #else
 101         entrylo = pte_to_entrylo(pte_val(pte));
 102 #endif
 103
 104         local_irq_save(flags);
 105         old_ctx = read_c0_entryhi();
 106         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 107         write_c0_entrylo0(entrylo);
 108         write_c0_entrylo1(entrylo);
 109         tlbidx = read_c0_wired();
 110         write_c0_wired(tlbidx + 1);
 111         write_c0_index(tlbidx);
 112         mtc0_tlbw_hazard();
 113         tlb_write_indexed();
 114         tlbw_use_hazard();
 115         write_c0_entryhi(old_ctx);
 116         local_irq_restore(flags);
 117
 118         return (void*) vaddr;
 119 }
 120
 121 void *kmap_coherent(struct page *page, unsigned long addr)
 122 {
 123         return __kmap_pgprot(page, addr, PAGE_KERNEL);
 124 }
 125
 126 void *kmap_noncoherent(struct page *page, unsigned long addr)
 127 {
 128         return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
 129 }
 130
 131 void kunmap_coherent(void)
 132 {
 133         unsigned int wired;
 134         unsigned long flags, old_ctx;
 135
 136         local_irq_save(flags);
 137         old_ctx = read_c0_entryhi();
 138         wired = read_c0_wired() - 1;
 139         write_c0_wired(wired);
 140         write_c0_index(wired);
 141         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 142         write_c0_entrylo0(0);
 143         write_c0_entrylo1(0);
 144         mtc0_tlbw_hazard();
 145         tlb_write_indexed();
 146         tlbw_use_hazard();
 147         write_c0_entryhi(old_ctx);
 148         local_irq_restore(flags);
 149         pagefault_enable();
 150 }
 151
 152 void copy_user_highpage(struct page *to, struct page *from,
 153         unsigned long vaddr, struct vm_area_struct *vma)
 154 {
 155         void *vfrom, *vto;
 156
 157         vto = kmap_atomic(to);
 158         if (cpu_has_dc_aliases &&
 159             page_mapped(from) && !Page_dcache_dirty(from)) {
 160                 vfrom = kmap_coherent(from, vaddr);
 161                 copy_page(vto, vfrom);
 162                 kunmap_coherent();
 163         } else {
 164                 vfrom = kmap_atomic(from);
 165                 copy_page(vto, vfrom);
 166                 kunmap_atomic(vfrom);
 167         }
 168         if ((!cpu_has_ic_fills_f_dc) ||
 169             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 170                 flush_data_cache_page((unsigned long)vto);
 171         kunmap_atomic(vto);
 172         /* Make sure this page is cleared on other CPU's too before using it */
 173         smp_wmb();
 174 }
 175
 176 void copy_to_user_page(struct vm_area_struct *vma,
 177         struct page *page, unsigned long vaddr, void *dst, const void *src,
 178         unsigned long len)
 179 {
 180         if (cpu_has_dc_aliases &&
 181             page_mapped(page) && !Page_dcache_dirty(page)) {
 182                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 183                 memcpy(vto, src, len);
 184                 kunmap_coherent();
 185         } else {
 186                 memcpy(dst, src, len);
 187                 if (cpu_has_dc_aliases)
 188                         SetPageDcacheDirty(page);
 189         }
 190         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 191                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 192 }
 193
 194 void copy_from_user_page(struct vm_area_struct *vma,
 195         struct page *page, unsigned long vaddr, void *dst, const void *src,
 196         unsigned long len)
 197 {
 198         if (cpu_has_dc_aliases &&
 199             page_mapped(page) && !Page_dcache_dirty(page)) {
 200                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 201                 memcpy(dst, vfrom, len);
 202                 kunmap_coherent();
 203         } else {
 204                 memcpy(dst, src, len);
 205                 if (cpu_has_dc_aliases)
 206                         SetPageDcacheDirty(page);
 207         }
 208 }
 209 EXPORT_SYMBOL_GPL(copy_from_user_page);
 210
 211 void __init fixrange_init(unsigned long start, unsigned long end,
 212         pgd_t *pgd_base)
 213 {
 214 #ifdef CONFIG_HIGHMEM
 215         pgd_t *pgd;
 216         pud_t *pud;
 217         pmd_t *pmd;
 218         pte_t *pte;
 219         int i, j, k;
 220         unsigned long vaddr;
 221
 222         vaddr = start;
 223         i = __pgd_offset(vaddr);
 224         j = __pud_offset(vaddr);
 225         k = __pmd_offset(vaddr);
 226         pgd = pgd_base + i;
 227
 228         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 229                 pud = (pud_t *)pgd;
 230                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 231                         pmd = (pmd_t *)pud;
 232                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 233                                 if (pmd_none(*pmd)) {
 234                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 235                                         set_pmd(pmd, __pmd((unsigned long)pte));
 236                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 237                                 }
 238                                 vaddr += PMD_SIZE;
 239                         }
 240                         k = 0;
 241                 }
 242                 j = 0;
 243         }
 244 #endif
 245 }
 246
 247 #ifndef CONFIG_NEED_MULTIPLE_NODES
 248 int page_is_ram(unsigned long pagenr)
 249 {
 250         int i;
 251
 252         for (i = 0; i < boot_mem_map.nr_map; i++) {
 253                 unsigned long addr, end;
 254
 255                 switch (boot_mem_map.map[i].type) {
 256                 case BOOT_MEM_RAM:
 257                 case BOOT_MEM_INIT_RAM:
 258                         break;
 259                 default:
 260                         /* not usable memory */
 261                         continue;
 262                 }
 263
 264                 addr = PFN_UP(boot_mem_map.map[i].addr);
 265                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 266                                boot_mem_map.map[i].size);
 267
 268                 if (pagenr >= addr && pagenr < end)
 269                         return 1;
 270         }
 271
 272         return 0;
 273 }
 274
 275 void __init paging_init(void)
 276 {
 277         unsigned long max_zone_pfns[MAX_NR_ZONES];
 278         unsigned long lastpfn __maybe_unused;
 279
 280         pagetable_init();
 281
 282 #ifdef CONFIG_HIGHMEM
 283         kmap_init();
 284 #endif
 285 #ifdef CONFIG_ZONE_DMA
 286         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 287 #endif
 288 #ifdef CONFIG_ZONE_DMA32
 289         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 290 #endif
 291         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 292         lastpfn = max_low_pfn;
 293 #ifdef CONFIG_HIGHMEM
 294         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 295         lastpfn = highend_pfn;
 296
 297         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 298                 printk(KERN_WARNING "This processor doesn't support highmem."
 299                        " %ldk highmem ignored\n",
 300                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 301                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 302                 lastpfn = max_low_pfn;
 303         }
 304 #endif
 305
 306         free_area_init_nodes(max_zone_pfns);
 307 }
 308
 309 #ifdef CONFIG_64BIT
 310 static struct kcore_list kcore_kseg0;
 311 #endif
 312
 313 static inline void mem_init_free_highmem(void)
 314 {
 315 #ifdef CONFIG_HIGHMEM
 316         unsigned long tmp;
 317
 318         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 319                 struct page *page = pfn_to_page(tmp);
 320
 321                 if (!page_is_ram(tmp))
 322                         SetPageReserved(page);
 323                 else
 324                         free_highmem_page(page);
 325         }
 326 #endif
 327 }
 328
 329 unsigned __weak platform_maar_init(unsigned num_maars)
 330 {
 331         return 0;
 332 }
 333
 334 static void maar_init(void)
 335 {
 336         unsigned num_maars, used, i;
 337
 338         if (!cpu_has_maar)
 339                 return;
 340
 341         /* Detect the number of MAARs */
 342         write_c0_maari(~0);
 343         back_to_back_c0_hazard();
 344         num_maars = read_c0_maari() + 1;
 345
 346         /* MAARs should be in pairs */
 347         WARN_ON(num_maars % 2);
 348
 349         /* Configure the required MAARs */
 350         used = platform_maar_init(num_maars / 2);
 351
 352         /* Disable any further MAARs */
 353         for (i = (used * 2); i < num_maars; i++) {
 354                 write_c0_maari(i);
 355                 back_to_back_c0_hazard();
 356                 write_c0_maar(0);
 357                 back_to_back_c0_hazard();
 358         }
 359 }
 360
 361 void __init mem_init(void)
 362 {
 363 #ifdef CONFIG_HIGHMEM
 364 #ifdef CONFIG_DISCONTIGMEM
 365 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 366 #endif
 367         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 368 #else
 369         max_mapnr = max_low_pfn;
 370 #endif
 371         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 372
 373         maar_init();
 374         free_all_bootmem();
 375         setup_zero_pages();     /* Setup zeroed pages.  */
 376         mem_init_free_highmem();
 377         mem_init_print_info(NULL);
 378
 379 #ifdef CONFIG_64BIT
 380         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 381                 /* The -4 is a hack so that user tools don't have to handle
 382                    the overflow.  */
 383                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 384                                 0x80000000 - 4, KCORE_TEXT);
 385 #endif
 386 }
 387 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 388
 389 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 390 {
 391         unsigned long pfn;
 392
 393         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 394                 struct page *page = pfn_to_page(pfn);
 395                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 396
 397                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 398                 free_reserved_page(page);
 399         }
 400         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 401 }
 402
 403 #ifdef CONFIG_BLK_DEV_INITRD
 404 void free_initrd_mem(unsigned long start, unsigned long end)
 405 {
 406         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 407                            "initrd");
 408 }
 409 #endif
 410
 411 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 412
 413 void __init_refok free_initmem(void)
 414 {
 415         prom_free_prom_memory();
 416         /*
 417          * Let the platform define a specific function to free the
 418          * init section since EVA may have used any possible mapping
 419          * between virtual and physical addresses.
 420          */
 421         if (free_init_pages_eva)
 422                 free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
 423         else
 424                 free_initmem_default(POISON_FREE_INITMEM);
 425 }
 426
 427 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 428 unsigned long pgd_current[NR_CPUS];
 429 #endif
 430
 431 /*
 432  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 433  * are constants.  So we use the variants from asm-offset.h until that gcc
 434  * will officially be retired.
 435  *
 436  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 437  * with a single LUI instruction in the TLB handlers.  If we used
 438  * __aligned(64K), its size would get rounded up to the alignment
 439  * size, and waste space.  So we place it in its own section and align
 440  * it in the linker script.
 441  */
 442 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 443 #ifndef __PAGETABLE_PMD_FOLDED
 444 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 445 #endif
 446 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;