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
  33 #include <asm/asm-offsets.h>
  34 #include <asm/bootinfo.h>
  35 #include <asm/cachectl.h>
  36 #include <asm/cpu.h>
  37 #include <asm/dma.h>
  38 #include <asm/kmap_types.h>
  39 #include <asm/mmu_context.h>
  40 #include <asm/sections.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/pgalloc.h>
  43 #include <asm/tlb.h>
  44 #include <asm/fixmap.h>
  45
  46 /* Atomicity and interruptability */
  47 #ifdef CONFIG_MIPS_MT_SMTC
  48
  49 #include <asm/mipsmtregs.h>
  50
  51 #define ENTER_CRITICAL(flags) \
  52         { \
  53         unsigned int mvpflags; \
  54         local_irq_save(flags);\
  55         mvpflags = dvpe()
  56 #define EXIT_CRITICAL(flags) \
  57         evpe(mvpflags); \
  58         local_irq_restore(flags); \
  59         }
  60 #else
  61
  62 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  63 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  64
  65 #endif /* CONFIG_MIPS_MT_SMTC */
  66
  67 /*
  68  * We have up to 8 empty zeroed pages so we can map one of the right colour
  69  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  70  * where we have to avoid VCED / VECI exceptions for good performance at
  71  * any price.  Since page is never written to after the initialization we
  72  * don't have to care about aliases on other CPUs.
  73  */
  74 unsigned long empty_zero_page, zero_page_mask;
  75 EXPORT_SYMBOL_GPL(empty_zero_page);
  76
  77 /*
  78  * Not static inline because used by IP27 special magic initialization code
  79  */
  80 unsigned long setup_zero_pages(void)
  81 {
  82         unsigned int order;
  83         unsigned long size;
  84         struct page *page;
  85
  86         if (cpu_has_vce)
  87                 order = 3;
  88         else
  89                 order = 0;
  90
  91         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  92         if (!empty_zero_page)
  93                 panic("Oh boy, that early out of memory?");
  94
  95         page = virt_to_page((void *)empty_zero_page);
  96         split_page(page, order);
  97         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
  98                 SetPageReserved(page);
  99                 page++;
 100         }
 101
 102         size = PAGE_SIZE << order;
 103         zero_page_mask = (size - 1) & PAGE_MASK;
 104
 105         return 1UL << order;
 106 }
 107
 108 #ifdef CONFIG_MIPS_MT_SMTC
 109 static pte_t *kmap_coherent_pte;
 110 static void __init kmap_coherent_init(void)
 111 {
 112         unsigned long vaddr;
 113
 114         /* cache the first coherent kmap pte */
 115         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 116         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 117 }
 118 #else
 119 static inline void kmap_coherent_init(void) {}
 120 #endif
 121
 122 void *kmap_coherent(struct page *page, unsigned long addr)
 123 {
 124         enum fixed_addresses idx;
 125         unsigned long vaddr, flags, entrylo;
 126         unsigned long old_ctx;
 127         pte_t pte;
 128         int tlbidx;
 129
 130         BUG_ON(Page_dcache_dirty(page));
 131
 132         inc_preempt_count();
 133         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 134 #ifdef CONFIG_MIPS_MT_SMTC
 135         idx += FIX_N_COLOURS * smp_processor_id() +
 136                 (in_interrupt() ? (FIX_N_COLOURS * NR_CPUS) : 0);
 137 #else
 138         idx += in_interrupt() ? FIX_N_COLOURS : 0;
 139 #endif
 140         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 141         pte = mk_pte(page, PAGE_KERNEL);
 142 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
 143         entrylo = pte.pte_high;
 144 #else
 145         entrylo = pte_to_entrylo(pte_val(pte));
 146 #endif
 147
 148         ENTER_CRITICAL(flags);
 149         old_ctx = read_c0_entryhi();
 150         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 151         write_c0_entrylo0(entrylo);
 152         write_c0_entrylo1(entrylo);
 153 #ifdef CONFIG_MIPS_MT_SMTC
 154         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 155         /* preload TLB instead of local_flush_tlb_one() */
 156         mtc0_tlbw_hazard();
 157         tlb_probe();
 158         tlb_probe_hazard();
 159         tlbidx = read_c0_index();
 160         mtc0_tlbw_hazard();
 161         if (tlbidx < 0)
 162                 tlb_write_random();
 163         else
 164                 tlb_write_indexed();
 165 #else
 166         tlbidx = read_c0_wired();
 167         write_c0_wired(tlbidx + 1);
 168         write_c0_index(tlbidx);
 169         mtc0_tlbw_hazard();
 170         tlb_write_indexed();
 171 #endif
 172         tlbw_use_hazard();
 173         write_c0_entryhi(old_ctx);
 174         EXIT_CRITICAL(flags);
 175
 176         return (void*) vaddr;
 177 }
 178
 179 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 180
 181 void kunmap_coherent(void)
 182 {
 183 #ifndef CONFIG_MIPS_MT_SMTC
 184         unsigned int wired;
 185         unsigned long flags, old_ctx;
 186
 187         ENTER_CRITICAL(flags);
 188         old_ctx = read_c0_entryhi();
 189         wired = read_c0_wired() - 1;
 190         write_c0_wired(wired);
 191         write_c0_index(wired);
 192         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 193         write_c0_entrylo0(0);
 194         write_c0_entrylo1(0);
 195         mtc0_tlbw_hazard();
 196         tlb_write_indexed();
 197         tlbw_use_hazard();
 198         write_c0_entryhi(old_ctx);
 199         EXIT_CRITICAL(flags);
 200 #endif
 201         dec_preempt_count();
 202         preempt_check_resched();
 203 }
 204
 205 void copy_user_highpage(struct page *to, struct page *from,
 206         unsigned long vaddr, struct vm_area_struct *vma)
 207 {
 208         void *vfrom, *vto;
 209
 210         vto = kmap_atomic(to);
 211         if (cpu_has_dc_aliases &&
 212             page_mapped(from) && !Page_dcache_dirty(from)) {
 213                 vfrom = kmap_coherent(from, vaddr);
 214                 copy_page(vto, vfrom);
 215                 kunmap_coherent();
 216         } else {
 217                 vfrom = kmap_atomic(from);
 218                 copy_page(vto, vfrom);
 219                 kunmap_atomic(vfrom);
 220         }
 221         if ((!cpu_has_ic_fills_f_dc) ||
 222             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 223                 flush_data_cache_page((unsigned long)vto);
 224         kunmap_atomic(vto);
 225         /* Make sure this page is cleared on other CPU's too before using it */
 226         smp_wmb();
 227 }
 228
 229 void copy_to_user_page(struct vm_area_struct *vma,
 230         struct page *page, unsigned long vaddr, void *dst, const void *src,
 231         unsigned long len)
 232 {
 233         if (cpu_has_dc_aliases &&
 234             page_mapped(page) && !Page_dcache_dirty(page)) {
 235                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 236                 memcpy(vto, src, len);
 237                 kunmap_coherent();
 238         } else {
 239                 memcpy(dst, src, len);
 240                 if (cpu_has_dc_aliases)
 241                         SetPageDcacheDirty(page);
 242         }
 243         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 244                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 245 }
 246
 247 void copy_from_user_page(struct vm_area_struct *vma,
 248         struct page *page, unsigned long vaddr, void *dst, const void *src,
 249         unsigned long len)
 250 {
 251         if (cpu_has_dc_aliases &&
 252             page_mapped(page) && !Page_dcache_dirty(page)) {
 253                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 254                 memcpy(dst, vfrom, len);
 255                 kunmap_coherent();
 256         } else {
 257                 memcpy(dst, src, len);
 258                 if (cpu_has_dc_aliases)
 259                         SetPageDcacheDirty(page);
 260         }
 261 }
 262
 263 void __init fixrange_init(unsigned long start, unsigned long end,
 264         pgd_t *pgd_base)
 265 {
 266 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 267         pgd_t *pgd;
 268         pud_t *pud;
 269         pmd_t *pmd;
 270         pte_t *pte;
 271         int i, j, k;
 272         unsigned long vaddr;
 273
 274         vaddr = start;
 275         i = __pgd_offset(vaddr);
 276         j = __pud_offset(vaddr);
 277         k = __pmd_offset(vaddr);
 278         pgd = pgd_base + i;
 279
 280         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 281                 pud = (pud_t *)pgd;
 282                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 283                         pmd = (pmd_t *)pud;
 284                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 285                                 if (pmd_none(*pmd)) {
 286                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 287                                         set_pmd(pmd, __pmd((unsigned long)pte));
 288                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 289                                 }
 290                                 vaddr += PMD_SIZE;
 291                         }
 292                         k = 0;
 293                 }
 294                 j = 0;
 295         }
 296 #endif
 297 }
 298
 299 #ifndef CONFIG_NEED_MULTIPLE_NODES
 300 int page_is_ram(unsigned long pagenr)
 301 {
 302         int i;
 303
 304         for (i = 0; i < boot_mem_map.nr_map; i++) {
 305                 unsigned long addr, end;
 306
 307                 switch (boot_mem_map.map[i].type) {
 308                 case BOOT_MEM_RAM:
 309                 case BOOT_MEM_INIT_RAM:
 310                         break;
 311                 default:
 312                         /* not usable memory */
 313                         continue;
 314                 }
 315
 316                 addr = PFN_UP(boot_mem_map.map[i].addr);
 317                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 318                                boot_mem_map.map[i].size);
 319
 320                 if (pagenr >= addr && pagenr < end)
 321                         return 1;
 322         }
 323
 324         return 0;
 325 }
 326
 327 void __init paging_init(void)
 328 {
 329         unsigned long max_zone_pfns[MAX_NR_ZONES];
 330         unsigned long lastpfn __maybe_unused;
 331
 332         pagetable_init();
 333
 334 #ifdef CONFIG_HIGHMEM
 335         kmap_init();
 336 #endif
 337         kmap_coherent_init();
 338
 339 #ifdef CONFIG_ZONE_DMA
 340         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 341 #endif
 342 #ifdef CONFIG_ZONE_DMA32
 343         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 344 #endif
 345         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 346         lastpfn = max_low_pfn;
 347 #ifdef CONFIG_HIGHMEM
 348         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 349         lastpfn = highend_pfn;
 350
 351         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 352                 printk(KERN_WARNING "This processor doesn't support highmem."
 353                        " %ldk highmem ignored\n",
 354                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 355                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 356                 lastpfn = max_low_pfn;
 357         }
 358 #endif
 359
 360         free_area_init_nodes(max_zone_pfns);
 361 }
 362
 363 #ifdef CONFIG_64BIT
 364 static struct kcore_list kcore_kseg0;
 365 #endif
 366
 367 void __init mem_init(void)
 368 {
 369         unsigned long codesize, reservedpages, datasize, initsize;
 370         unsigned long tmp, ram;
 371
 372 #ifdef CONFIG_HIGHMEM
 373 #ifdef CONFIG_DISCONTIGMEM
 374 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 375 #endif
 376         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 377 #else
 378         max_mapnr = max_low_pfn;
 379 #endif
 380         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 381
 382         totalram_pages += free_all_bootmem();
 383         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 384
 385         reservedpages = ram = 0;
 386         for (tmp = 0; tmp < max_low_pfn; tmp++)
 387                 if (page_is_ram(tmp) && pfn_valid(tmp)) {
 388                         ram++;
 389                         if (PageReserved(pfn_to_page(tmp)))
 390                                 reservedpages++;
 391                 }
 392         num_physpages = ram;
 393
 394 #ifdef CONFIG_HIGHMEM
 395         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 396                 struct page *page = pfn_to_page(tmp);
 397
 398                 if (!page_is_ram(tmp)) {
 399                         SetPageReserved(page);
 400                         continue;
 401                 }
 402                 ClearPageReserved(page);
 403                 init_page_count(page);
 404                 __free_page(page);
 405                 totalhigh_pages++;
 406         }
 407         totalram_pages += totalhigh_pages;
 408         num_physpages += totalhigh_pages;
 409 #endif
 410
 411         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 412         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 413         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 414
 415 #ifdef CONFIG_64BIT
 416         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 417                 /* The -4 is a hack so that user tools don't have to handle
 418                    the overflow.  */
 419                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 420                                 0x80000000 - 4, KCORE_TEXT);
 421 #endif
 422
 423         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 424                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 425                nr_free_pages() << (PAGE_SHIFT-10),
 426                ram << (PAGE_SHIFT-10),
 427                codesize >> 10,
 428                reservedpages << (PAGE_SHIFT-10),
 429                datasize >> 10,
 430                initsize >> 10,
 431                totalhigh_pages << (PAGE_SHIFT-10));
 432 }
 433 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 434
 435 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 436 {
 437         unsigned long pfn;
 438
 439         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 440                 struct page *page = pfn_to_page(pfn);
 441                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 442
 443                 ClearPageReserved(page);
 444                 init_page_count(page);
 445                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 446                 __free_page(page);
 447                 totalram_pages++;
 448         }
 449         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 450 }
 451
 452 #ifdef CONFIG_BLK_DEV_INITRD
 453 void free_initrd_mem(unsigned long start, unsigned long end)
 454 {
 455         free_init_pages("initrd memory",
 456                         virt_to_phys((void *)start),
 457                         virt_to_phys((void *)end));
 458 }
 459 #endif
 460
 461 void __init_refok free_initmem(void)
 462 {
 463         prom_free_prom_memory();
 464         free_init_pages("unused kernel memory",
 465                         __pa_symbol(&__init_begin),
 466                         __pa_symbol(&__init_end));
 467 }
 468
 469 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 470 unsigned long pgd_current[NR_CPUS];
 471 #endif
 472
 473 /*
 474  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 475  * are constants.  So we use the variants from asm-offset.h until that gcc
 476  * will officially be retired.
 477  *
 478  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 479  * with a single LUI instruction in the TLB handlers.  If we used
 480  * __aligned(64K), its size would get rounded up to the alignment
 481  * size, and waste space.  So we place it in its own section and align
 482  * it in the linker script.
 483  */
 484 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 485 #ifndef __PAGETABLE_PMD_FOLDED
 486 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 487 #endif
 488 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;