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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/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/string.h>
  19 #include <linux/types.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/mman.h>
  23 #include <linux/mm.h>
  24 #include <linux/bootmem.h>
  25 #include <linux/highmem.h>
  26 #include <linux/swap.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/pfn.h>
  29
  30 #include <asm/asm-offsets.h>
  31 #include <asm/bootinfo.h>
  32 #include <asm/cachectl.h>
  33 #include <asm/cpu.h>
  34 #include <asm/dma.h>
  35 #include <asm/kmap_types.h>
  36 #include <asm/mmu_context.h>
  37 #include <asm/sections.h>
  38 #include <asm/pgtable.h>
  39 #include <asm/pgalloc.h>
  40 #include <asm/tlb.h>
  41 #include <asm/fixmap.h>
  42
  43 /* Atomicity and interruptability */
  44 #ifdef CONFIG_MIPS_MT_SMTC
  45
  46 #include <asm/mipsmtregs.h>
  47
  48 #define ENTER_CRITICAL(flags) \
  49         { \
  50         unsigned int mvpflags; \
  51         local_irq_save(flags);\
  52         mvpflags = dvpe()
  53 #define EXIT_CRITICAL(flags) \
  54         evpe(mvpflags); \
  55         local_irq_restore(flags); \
  56         }
  57 #else
  58
  59 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  60 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  61
  62 #endif /* CONFIG_MIPS_MT_SMTC */
  63
  64 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  65
  66 /*
  67  * We have up to 8 empty zeroed pages so we can map one of the right colour
  68  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  69  * where we have to avoid VCED / VECI exceptions for good performance at
  70  * any price.  Since page is never written to after the initialization we
  71  * don't have to care about aliases on other CPUs.
  72  */
  73 unsigned long empty_zero_page, zero_page_mask;
  74 EXPORT_SYMBOL_GPL(empty_zero_page);
  75
  76 /*
  77  * Not static inline because used by IP27 special magic initialization code
  78  */
  79 unsigned long setup_zero_pages(void)
  80 {
  81         unsigned int order;
  82         unsigned long size;
  83         struct page *page;
  84
  85         if (cpu_has_vce)
  86                 order = 3;
  87         else
  88                 order = 0;
  89
  90         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  91         if (!empty_zero_page)
  92                 panic("Oh boy, that early out of memory?");
  93
  94         page = virt_to_page((void *)empty_zero_page);
  95         split_page(page, order);
  96         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
  97                 SetPageReserved(page);
  98                 page++;
  99         }
 100
 101         size = PAGE_SIZE << order;
 102         zero_page_mask = (size - 1) & PAGE_MASK;
 103
 104         return 1UL << order;
 105 }
 106
 107 #ifdef CONFIG_MIPS_MT_SMTC
 108 static pte_t *kmap_coherent_pte;
 109 static void __init kmap_coherent_init(void)
 110 {
 111         unsigned long vaddr;
 112
 113         /* cache the first coherent kmap pte */
 114         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 115         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 116 }
 117 #else
 118 static inline void kmap_coherent_init(void) {}
 119 #endif
 120
 121 void *kmap_coherent(struct page *page, unsigned long addr)
 122 {
 123         enum fixed_addresses idx;
 124         unsigned long vaddr, flags, entrylo;
 125         unsigned long old_ctx;
 126         pte_t pte;
 127         int tlbidx;
 128
 129         BUG_ON(Page_dcache_dirty(page));
 130
 131         inc_preempt_count();
 132         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 133 #ifdef CONFIG_MIPS_MT_SMTC
 134         idx += FIX_N_COLOURS * smp_processor_id();
 135 #endif
 136         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 137         pte = mk_pte(page, PAGE_KERNEL);
 138 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
 139         entrylo = pte.pte_high;
 140 #else
 141         entrylo = pte_val(pte) >> 6;
 142 #endif
 143
 144         ENTER_CRITICAL(flags);
 145         old_ctx = read_c0_entryhi();
 146         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 147         write_c0_entrylo0(entrylo);
 148         write_c0_entrylo1(entrylo);
 149 #ifdef CONFIG_MIPS_MT_SMTC
 150         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 151         /* preload TLB instead of local_flush_tlb_one() */
 152         mtc0_tlbw_hazard();
 153         tlb_probe();
 154         tlb_probe_hazard();
 155         tlbidx = read_c0_index();
 156         mtc0_tlbw_hazard();
 157         if (tlbidx < 0)
 158                 tlb_write_random();
 159         else
 160                 tlb_write_indexed();
 161 #else
 162         tlbidx = read_c0_wired();
 163         write_c0_wired(tlbidx + 1);
 164         write_c0_index(tlbidx);
 165         mtc0_tlbw_hazard();
 166         tlb_write_indexed();
 167 #endif
 168         tlbw_use_hazard();
 169         write_c0_entryhi(old_ctx);
 170         EXIT_CRITICAL(flags);
 171
 172         return (void*) vaddr;
 173 }
 174
 175 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 176
 177 void kunmap_coherent(void)
 178 {
 179 #ifndef CONFIG_MIPS_MT_SMTC
 180         unsigned int wired;
 181         unsigned long flags, old_ctx;
 182
 183         ENTER_CRITICAL(flags);
 184         old_ctx = read_c0_entryhi();
 185         wired = read_c0_wired() - 1;
 186         write_c0_wired(wired);
 187         write_c0_index(wired);
 188         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 189         write_c0_entrylo0(0);
 190         write_c0_entrylo1(0);
 191         mtc0_tlbw_hazard();
 192         tlb_write_indexed();
 193         tlbw_use_hazard();
 194         write_c0_entryhi(old_ctx);
 195         EXIT_CRITICAL(flags);
 196 #endif
 197         dec_preempt_count();
 198         preempt_check_resched();
 199 }
 200
 201 void copy_user_highpage(struct page *to, struct page *from,
 202         unsigned long vaddr, struct vm_area_struct *vma)
 203 {
 204         void *vfrom, *vto;
 205
 206         vto = kmap_atomic(to, KM_USER1);
 207         if (cpu_has_dc_aliases &&
 208             page_mapped(from) && !Page_dcache_dirty(from)) {
 209                 vfrom = kmap_coherent(from, vaddr);
 210                 copy_page(vto, vfrom);
 211                 kunmap_coherent();
 212         } else {
 213                 vfrom = kmap_atomic(from, KM_USER0);
 214                 copy_page(vto, vfrom);
 215                 kunmap_atomic(vfrom, KM_USER0);
 216         }
 217         if ((!cpu_has_ic_fills_f_dc) ||
 218             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 219                 flush_data_cache_page((unsigned long)vto);
 220         kunmap_atomic(vto, KM_USER1);
 221         /* Make sure this page is cleared on other CPU's too before using it */
 222         smp_wmb();
 223 }
 224
 225 void copy_to_user_page(struct vm_area_struct *vma,
 226         struct page *page, unsigned long vaddr, void *dst, const void *src,
 227         unsigned long len)
 228 {
 229         if (cpu_has_dc_aliases &&
 230             page_mapped(page) && !Page_dcache_dirty(page)) {
 231                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 232                 memcpy(vto, src, len);
 233                 kunmap_coherent();
 234         } else {
 235                 memcpy(dst, src, len);
 236                 if (cpu_has_dc_aliases)
 237                         SetPageDcacheDirty(page);
 238         }
 239         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 240                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 241 }
 242
 243 void copy_from_user_page(struct vm_area_struct *vma,
 244         struct page *page, unsigned long vaddr, void *dst, const void *src,
 245         unsigned long len)
 246 {
 247         if (cpu_has_dc_aliases &&
 248             page_mapped(page) && !Page_dcache_dirty(page)) {
 249                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 250                 memcpy(dst, vfrom, len);
 251                 kunmap_coherent();
 252         } else {
 253                 memcpy(dst, src, len);
 254                 if (cpu_has_dc_aliases)
 255                         SetPageDcacheDirty(page);
 256         }
 257 }
 258
 259 void __init fixrange_init(unsigned long start, unsigned long end,
 260         pgd_t *pgd_base)
 261 {
 262 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 263         pgd_t *pgd;
 264         pud_t *pud;
 265         pmd_t *pmd;
 266         pte_t *pte;
 267         int i, j, k;
 268         unsigned long vaddr;
 269
 270         vaddr = start;
 271         i = __pgd_offset(vaddr);
 272         j = __pud_offset(vaddr);
 273         k = __pmd_offset(vaddr);
 274         pgd = pgd_base + i;
 275
 276         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 277                 pud = (pud_t *)pgd;
 278                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 279                         pmd = (pmd_t *)pud;
 280                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 281                                 if (pmd_none(*pmd)) {
 282                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 283                                         set_pmd(pmd, __pmd((unsigned long)pte));
 284                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 285                                 }
 286                                 vaddr += PMD_SIZE;
 287                         }
 288                         k = 0;
 289                 }
 290                 j = 0;
 291         }
 292 #endif
 293 }
 294
 295 #ifndef CONFIG_NEED_MULTIPLE_NODES
 296 static int __init page_is_ram(unsigned long pagenr)
 297 {
 298         int i;
 299
 300         for (i = 0; i < boot_mem_map.nr_map; i++) {
 301                 unsigned long addr, end;
 302
 303                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 304                         /* not usable memory */
 305                         continue;
 306
 307                 addr = PFN_UP(boot_mem_map.map[i].addr);
 308                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 309                                boot_mem_map.map[i].size);
 310
 311                 if (pagenr >= addr && pagenr < end)
 312                         return 1;
 313         }
 314
 315         return 0;
 316 }
 317
 318 void __init paging_init(void)
 319 {
 320         unsigned long max_zone_pfns[MAX_NR_ZONES];
 321         unsigned long lastpfn;
 322
 323         pagetable_init();
 324
 325 #ifdef CONFIG_HIGHMEM
 326         kmap_init();
 327 #endif
 328         kmap_coherent_init();
 329
 330 #ifdef CONFIG_ZONE_DMA
 331         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 332 #endif
 333 #ifdef CONFIG_ZONE_DMA32
 334         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 335 #endif
 336         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 337         lastpfn = max_low_pfn;
 338 #ifdef CONFIG_HIGHMEM
 339         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 340         lastpfn = highend_pfn;
 341
 342         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 343                 printk(KERN_WARNING "This processor doesn't support highmem."
 344                        " %ldk highmem ignored\n",
 345                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 346                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 347                 lastpfn = max_low_pfn;
 348         }
 349 #endif
 350
 351         free_area_init_nodes(max_zone_pfns);
 352 }
 353
 354 static struct kcore_list kcore_mem, kcore_vmalloc;
 355 #ifdef CONFIG_64BIT
 356 static struct kcore_list kcore_kseg0;
 357 #endif
 358
 359 void __init mem_init(void)
 360 {
 361         unsigned long codesize, reservedpages, datasize, initsize;
 362         unsigned long tmp, ram;
 363
 364 #ifdef CONFIG_HIGHMEM
 365 #ifdef CONFIG_DISCONTIGMEM
 366 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 367 #endif
 368         max_mapnr = highend_pfn;
 369 #else
 370         max_mapnr = max_low_pfn;
 371 #endif
 372         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 373
 374         totalram_pages += free_all_bootmem();
 375         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 376
 377         reservedpages = ram = 0;
 378         for (tmp = 0; tmp < max_low_pfn; tmp++)
 379                 if (page_is_ram(tmp)) {
 380                         ram++;
 381                         if (PageReserved(pfn_to_page(tmp)))
 382                                 reservedpages++;
 383                 }
 384         num_physpages = ram;
 385
 386 #ifdef CONFIG_HIGHMEM
 387         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 388                 struct page *page = pfn_to_page(tmp);
 389
 390                 if (!page_is_ram(tmp)) {
 391                         SetPageReserved(page);
 392                         continue;
 393                 }
 394                 ClearPageReserved(page);
 395                 init_page_count(page);
 396                 __free_page(page);
 397                 totalhigh_pages++;
 398         }
 399         totalram_pages += totalhigh_pages;
 400         num_physpages += totalhigh_pages;
 401 #endif
 402
 403         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 404         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 405         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 406
 407 #ifdef CONFIG_64BIT
 408         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 409                 /* The -4 is a hack so that user tools don't have to handle
 410                    the overflow.  */
 411                 kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
 412 #endif
 413         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 414         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 415                    VMALLOC_END-VMALLOC_START);
 416
 417         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 418                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 419                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 420                ram << (PAGE_SHIFT-10),
 421                codesize >> 10,
 422                reservedpages << (PAGE_SHIFT-10),
 423                datasize >> 10,
 424                initsize >> 10,
 425                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 426 }
 427 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 428
 429 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 430 {
 431         unsigned long pfn;
 432
 433         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 434                 struct page *page = pfn_to_page(pfn);
 435                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 436
 437                 ClearPageReserved(page);
 438                 init_page_count(page);
 439                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 440                 __free_page(page);
 441                 totalram_pages++;
 442         }
 443         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 444 }
 445
 446 #ifdef CONFIG_BLK_DEV_INITRD
 447 void free_initrd_mem(unsigned long start, unsigned long end)
 448 {
 449         free_init_pages("initrd memory",
 450                         virt_to_phys((void *)start),
 451                         virt_to_phys((void *)end));
 452 }
 453 #endif
 454
 455 void __init_refok free_initmem(void)
 456 {
 457         prom_free_prom_memory();
 458         free_init_pages("unused kernel memory",
 459                         __pa_symbol(&__init_begin),
 460                         __pa_symbol(&__init_end));
 461 }
 462
 463 unsigned long pgd_current[NR_CPUS];
 464 /*
 465  * On 64-bit we've got three-level pagetables with a slightly
 466  * different layout ...
 467  */
 468 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
 469
 470 /*
 471  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 472  * are constants.  So we use the variants from asm-offset.h until that gcc
 473  * will officially be retired.
 474  */
 475 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
 476 #ifdef CONFIG_64BIT
 477 #ifdef MODULE_START
 478 pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 479 #endif
 480 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 481 #endif
 482 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);