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   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
  31 #include <asm/asm-offsets.h>
  32 #include <asm/bootinfo.h>
  33 #include <asm/cachectl.h>
  34 #include <asm/cpu.h>
  35 #include <asm/dma.h>
  36 #include <asm/kmap_types.h>
  37 #include <asm/mmu_context.h>
  38 #include <asm/sections.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/pgalloc.h>
  41 #include <asm/tlb.h>
  42 #include <asm/fixmap.h>
  43
  44 /* Atomicity and interruptability */
  45 #ifdef CONFIG_MIPS_MT_SMTC
  46
  47 #include <asm/mipsmtregs.h>
  48
  49 #define ENTER_CRITICAL(flags) \
  50         { \
  51         unsigned int mvpflags; \
  52         local_irq_save(flags);\
  53         mvpflags = dvpe()
  54 #define EXIT_CRITICAL(flags) \
  55         evpe(mvpflags); \
  56         local_irq_restore(flags); \
  57         }
  58 #else
  59
  60 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  61 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  62
  63 #endif /* CONFIG_MIPS_MT_SMTC */
  64
  65 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  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 #endif
 137         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 138         pte = mk_pte(page, PAGE_KERNEL);
 139 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
 140         entrylo = pte.pte_high;
 141 #else
 142         entrylo = pte_val(pte) >> 6;
 143 #endif
 144
 145         ENTER_CRITICAL(flags);
 146         old_ctx = read_c0_entryhi();
 147         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 148         write_c0_entrylo0(entrylo);
 149         write_c0_entrylo1(entrylo);
 150 #ifdef CONFIG_MIPS_MT_SMTC
 151         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 152         /* preload TLB instead of local_flush_tlb_one() */
 153         mtc0_tlbw_hazard();
 154         tlb_probe();
 155         tlb_probe_hazard();
 156         tlbidx = read_c0_index();
 157         mtc0_tlbw_hazard();
 158         if (tlbidx < 0)
 159                 tlb_write_random();
 160         else
 161                 tlb_write_indexed();
 162 #else
 163         tlbidx = read_c0_wired();
 164         write_c0_wired(tlbidx + 1);
 165         write_c0_index(tlbidx);
 166         mtc0_tlbw_hazard();
 167         tlb_write_indexed();
 168 #endif
 169         tlbw_use_hazard();
 170         write_c0_entryhi(old_ctx);
 171         EXIT_CRITICAL(flags);
 172
 173         return (void*) vaddr;
 174 }
 175
 176 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 177
 178 void kunmap_coherent(void)
 179 {
 180 #ifndef CONFIG_MIPS_MT_SMTC
 181         unsigned int wired;
 182         unsigned long flags, old_ctx;
 183
 184         ENTER_CRITICAL(flags);
 185         old_ctx = read_c0_entryhi();
 186         wired = read_c0_wired() - 1;
 187         write_c0_wired(wired);
 188         write_c0_index(wired);
 189         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 190         write_c0_entrylo0(0);
 191         write_c0_entrylo1(0);
 192         mtc0_tlbw_hazard();
 193         tlb_write_indexed();
 194         tlbw_use_hazard();
 195         write_c0_entryhi(old_ctx);
 196         EXIT_CRITICAL(flags);
 197 #endif
 198         dec_preempt_count();
 199         preempt_check_resched();
 200 }
 201
 202 void copy_user_highpage(struct page *to, struct page *from,
 203         unsigned long vaddr, struct vm_area_struct *vma)
 204 {
 205         void *vfrom, *vto;
 206
 207         vto = kmap_atomic(to, KM_USER1);
 208         if (cpu_has_dc_aliases &&
 209             page_mapped(from) && !Page_dcache_dirty(from)) {
 210                 vfrom = kmap_coherent(from, vaddr);
 211                 copy_page(vto, vfrom);
 212                 kunmap_coherent();
 213         } else {
 214                 vfrom = kmap_atomic(from, KM_USER0);
 215                 copy_page(vto, vfrom);
 216                 kunmap_atomic(vfrom, KM_USER0);
 217         }
 218         if ((!cpu_has_ic_fills_f_dc) ||
 219             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 220                 flush_data_cache_page((unsigned long)vto);
 221         kunmap_atomic(vto, KM_USER1);
 222         /* Make sure this page is cleared on other CPU's too before using it */
 223         smp_wmb();
 224 }
 225
 226 void copy_to_user_page(struct vm_area_struct *vma,
 227         struct page *page, unsigned long vaddr, void *dst, const void *src,
 228         unsigned long len)
 229 {
 230         if (cpu_has_dc_aliases &&
 231             page_mapped(page) && !Page_dcache_dirty(page)) {
 232                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 233                 memcpy(vto, src, len);
 234                 kunmap_coherent();
 235         } else {
 236                 memcpy(dst, src, len);
 237                 if (cpu_has_dc_aliases)
 238                         SetPageDcacheDirty(page);
 239         }
 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 void copy_from_user_page(struct vm_area_struct *vma,
 245         struct page *page, unsigned long vaddr, void *dst, const void *src,
 246         unsigned long len)
 247 {
 248         if (cpu_has_dc_aliases &&
 249             page_mapped(page) && !Page_dcache_dirty(page)) {
 250                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 251                 memcpy(dst, vfrom, len);
 252                 kunmap_coherent();
 253         } else {
 254                 memcpy(dst, src, len);
 255                 if (cpu_has_dc_aliases)
 256                         SetPageDcacheDirty(page);
 257         }
 258 }
 259
 260 void __init fixrange_init(unsigned long start, unsigned long end,
 261         pgd_t *pgd_base)
 262 {
 263 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 264         pgd_t *pgd;
 265         pud_t *pud;
 266         pmd_t *pmd;
 267         pte_t *pte;
 268         int i, j, k;
 269         unsigned long vaddr;
 270
 271         vaddr = start;
 272         i = __pgd_offset(vaddr);
 273         j = __pud_offset(vaddr);
 274         k = __pmd_offset(vaddr);
 275         pgd = pgd_base + i;
 276
 277         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 278                 pud = (pud_t *)pgd;
 279                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 280                         pmd = (pmd_t *)pud;
 281                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 282                                 if (pmd_none(*pmd)) {
 283                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 284                                         set_pmd(pmd, __pmd((unsigned long)pte));
 285                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 286                                 }
 287                                 vaddr += PMD_SIZE;
 288                         }
 289                         k = 0;
 290                 }
 291                 j = 0;
 292         }
 293 #endif
 294 }
 295
 296 #ifndef CONFIG_NEED_MULTIPLE_NODES
 297 static int __init page_is_ram(unsigned long pagenr)
 298 {
 299         int i;
 300
 301         for (i = 0; i < boot_mem_map.nr_map; i++) {
 302                 unsigned long addr, end;
 303
 304                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 305                         /* not usable memory */
 306                         continue;
 307
 308                 addr = PFN_UP(boot_mem_map.map[i].addr);
 309                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 310                                boot_mem_map.map[i].size);
 311
 312                 if (pagenr >= addr && pagenr < end)
 313                         return 1;
 314         }
 315
 316         return 0;
 317 }
 318
 319 void __init paging_init(void)
 320 {
 321         unsigned long max_zone_pfns[MAX_NR_ZONES];
 322         unsigned long lastpfn;
 323
 324         pagetable_init();
 325
 326 #ifdef CONFIG_HIGHMEM
 327         kmap_init();
 328 #endif
 329         kmap_coherent_init();
 330
 331 #ifdef CONFIG_ZONE_DMA
 332         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 333 #endif
 334 #ifdef CONFIG_ZONE_DMA32
 335         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 336 #endif
 337         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 338         lastpfn = max_low_pfn;
 339 #ifdef CONFIG_HIGHMEM
 340         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 341         lastpfn = highend_pfn;
 342
 343         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 344                 printk(KERN_WARNING "This processor doesn't support highmem."
 345                        " %ldk highmem ignored\n",
 346                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 347                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 348                 lastpfn = max_low_pfn;
 349         }
 350 #endif
 351
 352         free_area_init_nodes(max_zone_pfns);
 353 }
 354
 355 static struct kcore_list kcore_mem, kcore_vmalloc;
 356 #ifdef CONFIG_64BIT
 357 static struct kcore_list kcore_kseg0;
 358 #endif
 359
 360 void __init mem_init(void)
 361 {
 362         unsigned long codesize, reservedpages, datasize, initsize;
 363         unsigned long tmp, ram;
 364
 365 #ifdef CONFIG_HIGHMEM
 366 #ifdef CONFIG_DISCONTIGMEM
 367 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 368 #endif
 369         max_mapnr = highend_pfn;
 370 #else
 371         max_mapnr = max_low_pfn;
 372 #endif
 373         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 374
 375         totalram_pages += free_all_bootmem();
 376         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 377
 378         reservedpages = ram = 0;
 379         for (tmp = 0; tmp < max_low_pfn; tmp++)
 380                 if (page_is_ram(tmp)) {
 381                         ram++;
 382                         if (PageReserved(pfn_to_page(tmp)))
 383                                 reservedpages++;
 384                 }
 385         num_physpages = ram;
 386
 387 #ifdef CONFIG_HIGHMEM
 388         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 389                 struct page *page = pfn_to_page(tmp);
 390
 391                 if (!page_is_ram(tmp)) {
 392                         SetPageReserved(page);
 393                         continue;
 394                 }
 395                 ClearPageReserved(page);
 396                 init_page_count(page);
 397                 __free_page(page);
 398                 totalhigh_pages++;
 399         }
 400         totalram_pages += totalhigh_pages;
 401         num_physpages += totalhigh_pages;
 402 #endif
 403
 404         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 405         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 406         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 407
 408 #ifdef CONFIG_64BIT
 409         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 410                 /* The -4 is a hack so that user tools don't have to handle
 411                    the overflow.  */
 412                 kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
 413 #endif
 414         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 415         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 416                    VMALLOC_END-VMALLOC_START);
 417
 418         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 419                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 420                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 421                ram << (PAGE_SHIFT-10),
 422                codesize >> 10,
 423                reservedpages << (PAGE_SHIFT-10),
 424                datasize >> 10,
 425                initsize >> 10,
 426                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 427 }
 428 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 429
 430 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 431 {
 432         unsigned long pfn;
 433
 434         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 435                 struct page *page = pfn_to_page(pfn);
 436                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 437
 438                 ClearPageReserved(page);
 439                 init_page_count(page);
 440                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 441                 __free_page(page);
 442                 totalram_pages++;
 443         }
 444         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 445 }
 446
 447 #ifdef CONFIG_BLK_DEV_INITRD
 448 void free_initrd_mem(unsigned long start, unsigned long end)
 449 {
 450         free_init_pages("initrd memory",
 451                         virt_to_phys((void *)start),
 452                         virt_to_phys((void *)end));
 453 }
 454 #endif
 455
 456 void __init_refok free_initmem(void)
 457 {
 458         prom_free_prom_memory();
 459         free_init_pages("unused kernel memory",
 460                         __pa_symbol(&__init_begin),
 461                         __pa_symbol(&__init_end));
 462 }
 463
 464 unsigned long pgd_current[NR_CPUS];
 465 /*
 466  * On 64-bit we've got three-level pagetables with a slightly
 467  * different layout ...
 468  */
 469 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
 470
 471 /*
 472  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 473  * are constants.  So we use the variants from asm-offset.h until that gcc
 474  * will officially be retired.
 475  */
 476 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
 477 #ifdef CONFIG_64BIT
 478 #ifdef MODULE_START
 479 pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 480 #endif
 481 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 482 #endif
 483 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);