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/init.h>
  12 #include <linux/module.h>
  13 #include <linux/signal.h>
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/errno.h>
  17 #include <linux/string.h>
  18 #include <linux/types.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/ptrace.h>
  21 #include <linux/mman.h>
  22 #include <linux/mm.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/highmem.h>
  25 #include <linux/swap.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/pfn.h>
  28
  29 #include <asm/asm-offsets.h>
  30 #include <asm/bootinfo.h>
  31 #include <asm/cachectl.h>
  32 #include <asm/cpu.h>
  33 #include <asm/dma.h>
  34 #include <asm/kmap_types.h>
  35 #include <asm/mmu_context.h>
  36 #include <asm/sections.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/pgalloc.h>
  39 #include <asm/tlb.h>
  40 #include <asm/fixmap.h>
  41
  42 /* Atomicity and interruptability */
  43 #ifdef CONFIG_MIPS_MT_SMTC
  44
  45 #include <asm/mipsmtregs.h>
  46
  47 #define ENTER_CRITICAL(flags) \
  48         { \
  49         unsigned int mvpflags; \
  50         local_irq_save(flags);\
  51         mvpflags = dvpe()
  52 #define EXIT_CRITICAL(flags) \
  53         evpe(mvpflags); \
  54         local_irq_restore(flags); \
  55         }
  56 #else
  57
  58 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  59 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  60
  61 #endif /* CONFIG_MIPS_MT_SMTC */
  62
  63 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  64
  65 /*
  66  * We have up to 8 empty zeroed pages so we can map one of the right colour
  67  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  68  * where we have to avoid VCED / VECI exceptions for good performance at
  69  * any price.  Since page is never written to after the initialization we
  70  * don't have to care about aliases on other CPUs.
  71  */
  72 unsigned long empty_zero_page, zero_page_mask;
  73
  74 /*
  75  * Not static inline because used by IP27 special magic initialization code
  76  */
  77 unsigned long setup_zero_pages(void)
  78 {
  79         unsigned int order;
  80         unsigned long size;
  81         struct page *page;
  82
  83         if (cpu_has_vce)
  84                 order = 3;
  85         else
  86                 order = 0;
  87
  88         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  89         if (!empty_zero_page)
  90                 panic("Oh boy, that early out of memory?");
  91
  92         page = virt_to_page((void *)empty_zero_page);
  93         split_page(page, order);
  94         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
  95                 SetPageReserved(page);
  96                 page++;
  97         }
  98
  99         size = PAGE_SIZE << order;
 100         zero_page_mask = (size - 1) & PAGE_MASK;
 101
 102         return 1UL << order;
 103 }
 104
 105 /*
 106  * These are almost like kmap_atomic / kunmap_atmic except they take an
 107  * additional address argument as the hint.
 108  */
 109
 110 #define kmap_get_fixmap_pte(vaddr)                                      \
 111         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
 112
 113 #ifdef CONFIG_MIPS_MT_SMTC
 114 static pte_t *kmap_coherent_pte;
 115 static void __init kmap_coherent_init(void)
 116 {
 117         unsigned long vaddr;
 118
 119         /* cache the first coherent kmap pte */
 120         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 121         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 122 }
 123 #else
 124 static inline void kmap_coherent_init(void) {}
 125 #endif
 126
 127 void *kmap_coherent(struct page *page, unsigned long addr)
 128 {
 129         enum fixed_addresses idx;
 130         unsigned long vaddr, flags, entrylo;
 131         unsigned long old_ctx;
 132         pte_t pte;
 133         int tlbidx;
 134
 135         inc_preempt_count();
 136         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 137 #ifdef CONFIG_MIPS_MT_SMTC
 138         idx += FIX_N_COLOURS * smp_processor_id();
 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_R1)
 143         entrylo = pte.pte_high;
 144 #else
 145         entrylo = pte_val(pte) >> 6;
 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, KM_USER1);
 211         if (cpu_has_dc_aliases) {
 212                 vfrom = kmap_coherent(from, vaddr);
 213                 copy_page(vto, vfrom);
 214                 kunmap_coherent();
 215         } else {
 216                 vfrom = kmap_atomic(from, KM_USER0);
 217                 copy_page(vto, vfrom);
 218                 kunmap_atomic(vfrom, KM_USER0);
 219         }
 220         if (((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) ||
 221             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 222                 flush_data_cache_page((unsigned long)vto);
 223         kunmap_atomic(vto, KM_USER1);
 224         /* Make sure this page is cleared on other CPU's too before using it */
 225         smp_wmb();
 226 }
 227
 228 EXPORT_SYMBOL(copy_user_highpage);
 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                 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 ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 241                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 242 }
 243
 244 EXPORT_SYMBOL(copy_to_user_page);
 245
 246 void copy_from_user_page(struct vm_area_struct *vma,
 247         struct page *page, unsigned long vaddr, void *dst, const void *src,
 248         unsigned long len)
 249 {
 250         if (cpu_has_dc_aliases) {
 251                 void *vfrom =
 252                         kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 253                 memcpy(dst, vfrom, len);
 254                 kunmap_coherent();
 255         } else
 256                 memcpy(dst, src, len);
 257 }
 258
 259 EXPORT_SYMBOL(copy_from_user_page);
 260
 261
 262 #ifdef CONFIG_HIGHMEM
 263 unsigned long highstart_pfn, highend_pfn;
 264
 265 pte_t *kmap_pte;
 266 pgprot_t kmap_prot;
 267
 268 static void __init kmap_init(void)
 269 {
 270         unsigned long kmap_vstart;
 271
 272         /* cache the first kmap pte */
 273         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 274         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 275
 276         kmap_prot = PAGE_KERNEL;
 277 }
 278 #endif /* CONFIG_HIGHMEM */
 279
 280 void __init fixrange_init(unsigned long start, unsigned long end,
 281         pgd_t *pgd_base)
 282 {
 283 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 284         pgd_t *pgd;
 285         pud_t *pud;
 286         pmd_t *pmd;
 287         pte_t *pte;
 288         int i, j, k;
 289         unsigned long vaddr;
 290
 291         vaddr = start;
 292         i = __pgd_offset(vaddr);
 293         j = __pud_offset(vaddr);
 294         k = __pmd_offset(vaddr);
 295         pgd = pgd_base + i;
 296
 297         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 298                 pud = (pud_t *)pgd;
 299                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 300                         pmd = (pmd_t *)pud;
 301                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 302                                 if (pmd_none(*pmd)) {
 303                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 304                                         set_pmd(pmd, __pmd((unsigned long)pte));
 305                                         if (pte != pte_offset_kernel(pmd, 0))
 306                                                 BUG();
 307                                 }
 308                                 vaddr += PMD_SIZE;
 309                         }
 310                         k = 0;
 311                 }
 312                 j = 0;
 313         }
 314 #endif
 315 }
 316
 317 #ifndef CONFIG_NEED_MULTIPLE_NODES
 318 static int __init page_is_ram(unsigned long pagenr)
 319 {
 320         int i;
 321
 322         for (i = 0; i < boot_mem_map.nr_map; i++) {
 323                 unsigned long addr, end;
 324
 325                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 326                         /* not usable memory */
 327                         continue;
 328
 329                 addr = PFN_UP(boot_mem_map.map[i].addr);
 330                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 331                                boot_mem_map.map[i].size);
 332
 333                 if (pagenr >= addr && pagenr < end)
 334                         return 1;
 335         }
 336
 337         return 0;
 338 }
 339
 340 void __init paging_init(void)
 341 {
 342         unsigned long zones_size[MAX_NR_ZONES] = { 0, };
 343 #ifndef CONFIG_FLATMEM
 344         unsigned long zholes_size[MAX_NR_ZONES] = { 0, };
 345         unsigned long i, j, pfn;
 346 #endif
 347
 348         pagetable_init();
 349
 350 #ifdef CONFIG_HIGHMEM
 351         kmap_init();
 352 #endif
 353         kmap_coherent_init();
 354
 355 #ifdef CONFIG_ZONE_DMA
 356         if (min_low_pfn < MAX_DMA_PFN && MAX_DMA_PFN <= max_low_pfn) {
 357                 zones_size[ZONE_DMA] = MAX_DMA_PFN - min_low_pfn;
 358                 zones_size[ZONE_NORMAL] = max_low_pfn - MAX_DMA_PFN;
 359         } else if (max_low_pfn < MAX_DMA_PFN)
 360                 zones_size[ZONE_DMA] = max_low_pfn - min_low_pfn;
 361         else
 362 #endif
 363         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 364
 365 #ifdef CONFIG_HIGHMEM
 366         zones_size[ZONE_HIGHMEM] = highend_pfn - highstart_pfn;
 367
 368         if (cpu_has_dc_aliases && zones_size[ZONE_HIGHMEM]) {
 369                 printk(KERN_WARNING "This processor doesn't support highmem."
 370                        " %ldk highmem ignored\n", zones_size[ZONE_HIGHMEM]);
 371                 zones_size[ZONE_HIGHMEM] = 0;
 372         }
 373 #endif
 374
 375 #ifdef CONFIG_FLATMEM
 376         free_area_init(zones_size);
 377 #else
 378         pfn = min_low_pfn;
 379         for (i = 0; i < MAX_NR_ZONES; i++)
 380                 for (j = 0; j < zones_size[i]; j++, pfn++)
 381                         if (!page_is_ram(pfn))
 382                                 zholes_size[i]++;
 383         free_area_init_node(0, NODE_DATA(0), zones_size, 0, zholes_size);
 384 #endif
 385 }
 386
 387 static struct kcore_list kcore_mem, kcore_vmalloc;
 388 #ifdef CONFIG_64BIT
 389 static struct kcore_list kcore_kseg0;
 390 #endif
 391
 392 void __init mem_init(void)
 393 {
 394         unsigned long codesize, reservedpages, datasize, initsize;
 395         unsigned long tmp, ram;
 396
 397 #ifdef CONFIG_HIGHMEM
 398 #ifdef CONFIG_DISCONTIGMEM
 399 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 400 #endif
 401         max_mapnr = highend_pfn;
 402 #else
 403         max_mapnr = max_low_pfn;
 404 #endif
 405         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 406
 407         totalram_pages += free_all_bootmem();
 408         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 409
 410         reservedpages = ram = 0;
 411         for (tmp = 0; tmp < max_low_pfn; tmp++)
 412                 if (page_is_ram(tmp)) {
 413                         ram++;
 414                         if (PageReserved(pfn_to_page(tmp)))
 415                                 reservedpages++;
 416                 }
 417         num_physpages = ram;
 418
 419 #ifdef CONFIG_HIGHMEM
 420         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 421                 struct page *page = mem_map + tmp;
 422
 423                 if (!page_is_ram(tmp)) {
 424                         SetPageReserved(page);
 425                         continue;
 426                 }
 427                 ClearPageReserved(page);
 428                 init_page_count(page);
 429                 __free_page(page);
 430                 totalhigh_pages++;
 431         }
 432         totalram_pages += totalhigh_pages;
 433         num_physpages += totalhigh_pages;
 434 #endif
 435
 436         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 437         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 438         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 439
 440 #ifdef CONFIG_64BIT
 441         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 442                 /* The -4 is a hack so that user tools don't have to handle
 443                    the overflow.  */
 444                 kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
 445 #endif
 446         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 447         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 448                    VMALLOC_END-VMALLOC_START);
 449
 450         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 451                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 452                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 453                ram << (PAGE_SHIFT-10),
 454                codesize >> 10,
 455                reservedpages << (PAGE_SHIFT-10),
 456                datasize >> 10,
 457                initsize >> 10,
 458                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 459 }
 460 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 461
 462 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 463 {
 464         unsigned long pfn;
 465
 466         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 467                 struct page *page = pfn_to_page(pfn);
 468                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 469
 470                 ClearPageReserved(page);
 471                 init_page_count(page);
 472                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 473                 __free_page(page);
 474                 totalram_pages++;
 475         }
 476         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 477 }
 478
 479 #ifdef CONFIG_BLK_DEV_INITRD
 480 void free_initrd_mem(unsigned long start, unsigned long end)
 481 {
 482         free_init_pages("initrd memory",
 483                         virt_to_phys((void *)start),
 484                         virt_to_phys((void *)end));
 485 }
 486 #endif
 487
 488 void __init_refok free_initmem(void)
 489 {
 490         prom_free_prom_memory();
 491         free_init_pages("unused kernel memory",
 492                         __pa_symbol(&__init_begin),
 493                         __pa_symbol(&__init_end));
 494 }
 495
 496 unsigned long pgd_current[NR_CPUS];
 497 /*
 498  * On 64-bit we've got three-level pagetables with a slightly
 499  * different layout ...
 500  */
 501 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
 502
 503 /*
 504  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 505  * are constants.  So we use the variants from asm-offset.h until that gcc
 506  * will officially be retired.
 507  */
 508 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
 509 #ifdef CONFIG_64BIT
 510 #ifdef MODULE_START
 511 pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 512 #endif
 513 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 514 #endif
 515 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);