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 /* Atomicity and interruptability */
  48 #ifdef CONFIG_MIPS_MT_SMTC
  49
  50 #include <asm/mipsmtregs.h>
  51
  52 #define ENTER_CRITICAL(flags) \
  53         { \
  54         unsigned int mvpflags; \
  55         local_irq_save(flags);\
  56         mvpflags = dvpe()
  57 #define EXIT_CRITICAL(flags) \
  58         evpe(mvpflags); \
  59         local_irq_restore(flags); \
  60         }
  61 #else
  62
  63 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  64 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  65
  66 #endif /* CONFIG_MIPS_MT_SMTC */
  67
  68 /*
  69  * We have up to 8 empty zeroed pages so we can map one of the right colour
  70  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  71  * where we have to avoid VCED / VECI exceptions for good performance at
  72  * any price.  Since page is never written to after the initialization we
  73  * don't have to care about aliases on other CPUs.
  74  */
  75 unsigned long empty_zero_page, zero_page_mask;
  76 EXPORT_SYMBOL_GPL(empty_zero_page);
  77
  78 /*
  79  * Not static inline because used by IP27 special magic initialization code
  80  */
  81 unsigned long setup_zero_pages(void)
  82 {
  83         unsigned int order;
  84         unsigned long size;
  85         struct page *page;
  86
  87         if (cpu_has_vce)
  88                 order = 3;
  89         else
  90                 order = 0;
  91
  92         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  93         if (!empty_zero_page)
  94                 panic("Oh boy, that early out of memory?");
  95
  96         page = virt_to_page((void *)empty_zero_page);
  97         split_page(page, order);
  98         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
  99                 SetPageReserved(page);
 100                 page++;
 101         }
 102
 103         size = PAGE_SIZE << order;
 104         zero_page_mask = (size - 1) & PAGE_MASK;
 105
 106         return 1UL << order;
 107 }
 108
 109 #ifdef CONFIG_MIPS_MT_SMTC
 110 static pte_t *kmap_coherent_pte;
 111 static void __init kmap_coherent_init(void)
 112 {
 113         unsigned long vaddr;
 114
 115         /* cache the first coherent kmap pte */
 116         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 117         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 118 }
 119 #else
 120 static inline void kmap_coherent_init(void) {}
 121 #endif
 122
 123 void *kmap_coherent(struct page *page, unsigned long addr)
 124 {
 125         enum fixed_addresses idx;
 126         unsigned long vaddr, flags, entrylo;
 127         unsigned long old_ctx;
 128         pte_t pte;
 129         int tlbidx;
 130
 131         BUG_ON(Page_dcache_dirty(page));
 132
 133         inc_preempt_count();
 134         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 135 #ifdef CONFIG_MIPS_MT_SMTC
 136         idx += FIX_N_COLOURS * smp_processor_id() +
 137                 (in_interrupt() ? (FIX_N_COLOURS * NR_CPUS) : 0);
 138 #else
 139         idx += in_interrupt() ? FIX_N_COLOURS : 0;
 140 #endif
 141         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 142         pte = mk_pte(page, PAGE_KERNEL);
 143 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
 144         entrylo = pte.pte_high;
 145 #else
 146         entrylo = pte_to_entrylo(pte_val(pte));
 147 #endif
 148
 149         ENTER_CRITICAL(flags);
 150         old_ctx = read_c0_entryhi();
 151         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 152         write_c0_entrylo0(entrylo);
 153         write_c0_entrylo1(entrylo);
 154 #ifdef CONFIG_MIPS_MT_SMTC
 155         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 156         /* preload TLB instead of local_flush_tlb_one() */
 157         mtc0_tlbw_hazard();
 158         tlb_probe();
 159         tlb_probe_hazard();
 160         tlbidx = read_c0_index();
 161         mtc0_tlbw_hazard();
 162         if (tlbidx < 0)
 163                 tlb_write_random();
 164         else
 165                 tlb_write_indexed();
 166 #else
 167         tlbidx = read_c0_wired();
 168         write_c0_wired(tlbidx + 1);
 169         write_c0_index(tlbidx);
 170         mtc0_tlbw_hazard();
 171         tlb_write_indexed();
 172 #endif
 173         tlbw_use_hazard();
 174         write_c0_entryhi(old_ctx);
 175         EXIT_CRITICAL(flags);
 176
 177         return (void*) vaddr;
 178 }
 179
 180 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 181
 182 void kunmap_coherent(void)
 183 {
 184 #ifndef CONFIG_MIPS_MT_SMTC
 185         unsigned int wired;
 186         unsigned long flags, old_ctx;
 187
 188         ENTER_CRITICAL(flags);
 189         old_ctx = read_c0_entryhi();
 190         wired = read_c0_wired() - 1;
 191         write_c0_wired(wired);
 192         write_c0_index(wired);
 193         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 194         write_c0_entrylo0(0);
 195         write_c0_entrylo1(0);
 196         mtc0_tlbw_hazard();
 197         tlb_write_indexed();
 198         tlbw_use_hazard();
 199         write_c0_entryhi(old_ctx);
 200         EXIT_CRITICAL(flags);
 201 #endif
 202         dec_preempt_count();
 203         preempt_check_resched();
 204 }
 205
 206 void copy_user_highpage(struct page *to, struct page *from,
 207         unsigned long vaddr, struct vm_area_struct *vma)
 208 {
 209         void *vfrom, *vto;
 210
 211         vto = kmap_atomic(to);
 212         if (cpu_has_dc_aliases &&
 213             page_mapped(from) && !Page_dcache_dirty(from)) {
 214                 vfrom = kmap_coherent(from, vaddr);
 215                 copy_page(vto, vfrom);
 216                 kunmap_coherent();
 217         } else {
 218                 vfrom = kmap_atomic(from);
 219                 copy_page(vto, vfrom);
 220                 kunmap_atomic(vfrom);
 221         }
 222         if ((!cpu_has_ic_fills_f_dc) ||
 223             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 224                 flush_data_cache_page((unsigned long)vto);
 225         kunmap_atomic(vto);
 226         /* Make sure this page is cleared on other CPU's too before using it */
 227         smp_wmb();
 228 }
 229
 230 void copy_to_user_page(struct vm_area_struct *vma,
 231         struct page *page, unsigned long vaddr, void *dst, const void *src,
 232         unsigned long len)
 233 {
 234         if (cpu_has_dc_aliases &&
 235             page_mapped(page) && !Page_dcache_dirty(page)) {
 236                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 237                 memcpy(vto, src, len);
 238                 kunmap_coherent();
 239         } else {
 240                 memcpy(dst, src, len);
 241                 if (cpu_has_dc_aliases)
 242                         SetPageDcacheDirty(page);
 243         }
 244         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 245                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 246 }
 247
 248 void copy_from_user_page(struct vm_area_struct *vma,
 249         struct page *page, unsigned long vaddr, void *dst, const void *src,
 250         unsigned long len)
 251 {
 252         if (cpu_has_dc_aliases &&
 253             page_mapped(page) && !Page_dcache_dirty(page)) {
 254                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 255                 memcpy(dst, vfrom, len);
 256                 kunmap_coherent();
 257         } else {
 258                 memcpy(dst, src, len);
 259                 if (cpu_has_dc_aliases)
 260                         SetPageDcacheDirty(page);
 261         }
 262 }
 263
 264 void __init fixrange_init(unsigned long start, unsigned long end,
 265         pgd_t *pgd_base)
 266 {
 267 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 268         pgd_t *pgd;
 269         pud_t *pud;
 270         pmd_t *pmd;
 271         pte_t *pte;
 272         int i, j, k;
 273         unsigned long vaddr;
 274
 275         vaddr = start;
 276         i = __pgd_offset(vaddr);
 277         j = __pud_offset(vaddr);
 278         k = __pmd_offset(vaddr);
 279         pgd = pgd_base + i;
 280
 281         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 282                 pud = (pud_t *)pgd;
 283                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 284                         pmd = (pmd_t *)pud;
 285                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 286                                 if (pmd_none(*pmd)) {
 287                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 288                                         set_pmd(pmd, __pmd((unsigned long)pte));
 289                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 290                                 }
 291                                 vaddr += PMD_SIZE;
 292                         }
 293                         k = 0;
 294                 }
 295                 j = 0;
 296         }
 297 #endif
 298 }
 299
 300 #ifndef CONFIG_NEED_MULTIPLE_NODES
 301 int page_is_ram(unsigned long pagenr)
 302 {
 303         int i;
 304
 305         for (i = 0; i < boot_mem_map.nr_map; i++) {
 306                 unsigned long addr, end;
 307
 308                 switch (boot_mem_map.map[i].type) {
 309                 case BOOT_MEM_RAM:
 310                 case BOOT_MEM_INIT_RAM:
 311                         break;
 312                 default:
 313                         /* not usable memory */
 314                         continue;
 315                 }
 316
 317                 addr = PFN_UP(boot_mem_map.map[i].addr);
 318                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 319                                boot_mem_map.map[i].size);
 320
 321                 if (pagenr >= addr && pagenr < end)
 322                         return 1;
 323         }
 324
 325         return 0;
 326 }
 327
 328 void __init paging_init(void)
 329 {
 330         unsigned long max_zone_pfns[MAX_NR_ZONES];
 331         unsigned long lastpfn __maybe_unused;
 332
 333         pagetable_init();
 334
 335 #ifdef CONFIG_HIGHMEM
 336         kmap_init();
 337 #endif
 338         kmap_coherent_init();
 339
 340 #ifdef CONFIG_ZONE_DMA
 341         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 342 #endif
 343 #ifdef CONFIG_ZONE_DMA32
 344         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 345 #endif
 346         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 347         lastpfn = max_low_pfn;
 348 #ifdef CONFIG_HIGHMEM
 349         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 350         lastpfn = highend_pfn;
 351
 352         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 353                 printk(KERN_WARNING "This processor doesn't support highmem."
 354                        " %ldk highmem ignored\n",
 355                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 356                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 357                 lastpfn = max_low_pfn;
 358         }
 359 #endif
 360
 361         free_area_init_nodes(max_zone_pfns);
 362 }
 363
 364 #ifdef CONFIG_64BIT
 365 static struct kcore_list kcore_kseg0;
 366 #endif
 367
 368 void __init mem_init(void)
 369 {
 370         unsigned long codesize, reservedpages, datasize, initsize;
 371         unsigned long tmp, ram;
 372
 373 #ifdef CONFIG_HIGHMEM
 374 #ifdef CONFIG_DISCONTIGMEM
 375 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 376 #endif
 377         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 378 #else
 379         max_mapnr = max_low_pfn;
 380 #endif
 381         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 382
 383         totalram_pages += free_all_bootmem();
 384         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 385
 386         reservedpages = ram = 0;
 387         for (tmp = 0; tmp < max_low_pfn; tmp++)
 388                 if (page_is_ram(tmp) && pfn_valid(tmp)) {
 389                         ram++;
 390                         if (PageReserved(pfn_to_page(tmp)))
 391                                 reservedpages++;
 392                 }
 393         num_physpages = ram;
 394
 395 #ifdef CONFIG_HIGHMEM
 396         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 397                 struct page *page = pfn_to_page(tmp);
 398
 399                 if (!page_is_ram(tmp)) {
 400                         SetPageReserved(page);
 401                         continue;
 402                 }
 403                 ClearPageReserved(page);
 404                 init_page_count(page);
 405                 __free_page(page);
 406                 totalhigh_pages++;
 407         }
 408         totalram_pages += totalhigh_pages;
 409         num_physpages += totalhigh_pages;
 410 #endif
 411
 412         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 413         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 414         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 415
 416 #ifdef CONFIG_64BIT
 417         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 418                 /* The -4 is a hack so that user tools don't have to handle
 419                    the overflow.  */
 420                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 421                                 0x80000000 - 4, KCORE_TEXT);
 422 #endif
 423
 424         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 425                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 426                nr_free_pages() << (PAGE_SHIFT-10),
 427                ram << (PAGE_SHIFT-10),
 428                codesize >> 10,
 429                reservedpages << (PAGE_SHIFT-10),
 430                datasize >> 10,
 431                initsize >> 10,
 432                totalhigh_pages << (PAGE_SHIFT-10));
 433 }
 434 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 435
 436 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 437 {
 438         unsigned long pfn;
 439
 440         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 441                 struct page *page = pfn_to_page(pfn);
 442                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 443
 444                 ClearPageReserved(page);
 445                 init_page_count(page);
 446                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 447                 __free_page(page);
 448                 totalram_pages++;
 449         }
 450         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 451 }
 452
 453 #ifdef CONFIG_BLK_DEV_INITRD
 454 void free_initrd_mem(unsigned long start, unsigned long end)
 455 {
 456         free_init_pages("initrd memory",
 457                         virt_to_phys((void *)start),
 458                         virt_to_phys((void *)end));
 459 }
 460 #endif
 461
 462 void __init_refok free_initmem(void)
 463 {
 464         prom_free_prom_memory();
 465         free_init_pages("unused kernel memory",
 466                         __pa_symbol(&__init_begin),
 467                         __pa_symbol(&__init_end));
 468 }
 469
 470 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 471 unsigned long pgd_current[NR_CPUS];
 472 #endif
 473
 474 /*
 475  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 476  * are constants.  So we use the variants from asm-offset.h until that gcc
 477  * will officially be retired.
 478  *
 479  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 480  * with a single LUI instruction in the TLB handlers.  If we used
 481  * __aligned(64K), its size would get rounded up to the alignment
 482  * size, and waste space.  So we place it in its own section and align
 483  * it in the linker script.
 484  */
 485 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 486 #ifndef __PAGETABLE_PMD_FOLDED
 487 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 488 #endif
 489 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;