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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/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/bootinfo.h>
  30 #include <asm/cachectl.h>
  31 #include <asm/cpu.h>
  32 #include <asm/dma.h>
  33 #include <asm/kmap_types.h>
  34 #include <asm/mmu_context.h>
  35 #include <asm/sections.h>
  36 #include <asm/pgtable.h>
  37 #include <asm/pgalloc.h>
  38 #include <asm/tlb.h>
  39 #include <asm/fixmap.h>
  40
  41 /* Atomicity and interruptability */
  42 #ifdef CONFIG_MIPS_MT_SMTC
  43
  44 #include <asm/mipsmtregs.h>
  45
  46 #define ENTER_CRITICAL(flags) \
  47         { \
  48         unsigned int mvpflags; \
  49         local_irq_save(flags);\
  50         mvpflags = dvpe()
  51 #define EXIT_CRITICAL(flags) \
  52         evpe(mvpflags); \
  53         local_irq_restore(flags); \
  54         }
  55 #else
  56
  57 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  58 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  59
  60 #endif /* CONFIG_MIPS_MT_SMTC */
  61
  62 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  63
  64 /*
  65  * We have up to 8 empty zeroed pages so we can map one of the right colour
  66  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  67  * where we have to avoid VCED / VECI exceptions for good performance at
  68  * any price.  Since page is never written to after the initialization we
  69  * don't have to care about aliases on other CPUs.
  70  */
  71 unsigned long empty_zero_page, zero_page_mask;
  72
  73 /*
  74  * Not static inline because used by IP27 special magic initialization code
  75  */
  76 unsigned long setup_zero_pages(void)
  77 {
  78         unsigned int order;
  79         unsigned long size;
  80         struct page *page;
  81
  82         if (cpu_has_vce)
  83                 order = 3;
  84         else
  85                 order = 0;
  86
  87         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  88         if (!empty_zero_page)
  89                 panic("Oh boy, that early out of memory?");
  90
  91         page = virt_to_page((void *)empty_zero_page);
  92         split_page(page, order);
  93         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
  94                 SetPageReserved(page);
  95                 page++;
  96         }
  97
  98         size = PAGE_SIZE << order;
  99         zero_page_mask = (size - 1) & PAGE_MASK;
 100
 101         return 1UL << order;
 102 }
 103
 104 /*
 105  * These are almost like kmap_atomic / kunmap_atmic except they take an
 106  * additional address argument as the hint.
 107  */
 108
 109 #define kmap_get_fixmap_pte(vaddr)                                      \
 110         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
 111
 112 #ifdef CONFIG_MIPS_MT_SMTC
 113 static pte_t *kmap_coherent_pte;
 114 static void __init kmap_coherent_init(void)
 115 {
 116         unsigned long vaddr;
 117
 118         /* cache the first coherent kmap pte */
 119         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 120         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 121 }
 122 #else
 123 static inline void kmap_coherent_init(void) {}
 124 #endif
 125
 126 void *kmap_coherent(struct page *page, unsigned long addr)
 127 {
 128         enum fixed_addresses idx;
 129         unsigned long vaddr, flags, entrylo;
 130         unsigned long old_ctx;
 131         pte_t pte;
 132         int tlbidx;
 133
 134         inc_preempt_count();
 135         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 136 #ifdef CONFIG_MIPS_MT_SMTC
 137         idx += FIX_N_COLOURS * smp_processor_id();
 138 #endif
 139         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 140         pte = mk_pte(page, PAGE_KERNEL);
 141 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32_R1)
 142         entrylo = pte.pte_high;
 143 #else
 144         entrylo = pte_val(pte) >> 6;
 145 #endif
 146
 147         ENTER_CRITICAL(flags);
 148         old_ctx = read_c0_entryhi();
 149         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 150         write_c0_entrylo0(entrylo);
 151         write_c0_entrylo1(entrylo);
 152 #ifdef CONFIG_MIPS_MT_SMTC
 153         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 154         /* preload TLB instead of local_flush_tlb_one() */
 155         mtc0_tlbw_hazard();
 156         tlb_probe();
 157         tlb_probe_hazard();
 158         tlbidx = read_c0_index();
 159         mtc0_tlbw_hazard();
 160         if (tlbidx < 0)
 161                 tlb_write_random();
 162         else
 163                 tlb_write_indexed();
 164 #else
 165         tlbidx = read_c0_wired();
 166         write_c0_wired(tlbidx + 1);
 167         write_c0_index(tlbidx);
 168         mtc0_tlbw_hazard();
 169         tlb_write_indexed();
 170 #endif
 171         tlbw_use_hazard();
 172         write_c0_entryhi(old_ctx);
 173         EXIT_CRITICAL(flags);
 174
 175         return (void*) vaddr;
 176 }
 177
 178 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 179
 180 void kunmap_coherent(void)
 181 {
 182 #ifndef CONFIG_MIPS_MT_SMTC
 183         unsigned int wired;
 184         unsigned long flags, old_ctx;
 185
 186         ENTER_CRITICAL(flags);
 187         old_ctx = read_c0_entryhi();
 188         wired = read_c0_wired() - 1;
 189         write_c0_wired(wired);
 190         write_c0_index(wired);
 191         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 192         write_c0_entrylo0(0);
 193         write_c0_entrylo1(0);
 194         mtc0_tlbw_hazard();
 195         tlb_write_indexed();
 196         tlbw_use_hazard();
 197         write_c0_entryhi(old_ctx);
 198         EXIT_CRITICAL(flags);
 199 #endif
 200         dec_preempt_count();
 201         preempt_check_resched();
 202 }
 203
 204 void copy_user_highpage(struct page *to, struct page *from,
 205         unsigned long vaddr, struct vm_area_struct *vma)
 206 {
 207         void *vfrom, *vto;
 208
 209         vto = kmap_atomic(to, KM_USER1);
 210         if (cpu_has_dc_aliases) {
 211                 vfrom = kmap_coherent(from, vaddr);
 212                 copy_page(vto, vfrom);
 213                 kunmap_coherent();
 214         } else {
 215                 vfrom = kmap_atomic(from, KM_USER0);
 216                 copy_page(vto, vfrom);
 217                 kunmap_atomic(vfrom, KM_USER0);
 218         }
 219         if (((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) ||
 220             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 221                 flush_data_cache_page((unsigned long)vto);
 222         kunmap_atomic(vto, KM_USER1);
 223         /* Make sure this page is cleared on other CPU's too before using it */
 224         smp_wmb();
 225 }
 226
 227 EXPORT_SYMBOL(copy_user_highpage);
 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                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 235                 memcpy(vto, src, len);
 236                 kunmap_coherent();
 237         } else
 238                 memcpy(dst, src, len);
 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 EXPORT_SYMBOL(copy_to_user_page);
 244
 245 void copy_from_user_page(struct vm_area_struct *vma,
 246         struct page *page, unsigned long vaddr, void *dst, const void *src,
 247         unsigned long len)
 248 {
 249         if (cpu_has_dc_aliases) {
 250                 void *vfrom =
 251                         kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 252                 memcpy(dst, vfrom, len);
 253                 kunmap_coherent();
 254         } else
 255                 memcpy(dst, src, len);
 256 }
 257
 258 EXPORT_SYMBOL(copy_from_user_page);
 259
 260
 261 #ifdef CONFIG_HIGHMEM
 262 unsigned long highstart_pfn, highend_pfn;
 263
 264 pte_t *kmap_pte;
 265 pgprot_t kmap_prot;
 266
 267 static void __init kmap_init(void)
 268 {
 269         unsigned long kmap_vstart;
 270
 271         /* cache the first kmap pte */
 272         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 273         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 274
 275         kmap_prot = PAGE_KERNEL;
 276 }
 277 #endif /* CONFIG_HIGHMEM */
 278
 279 void __init fixrange_init(unsigned long start, unsigned long end,
 280         pgd_t *pgd_base)
 281 {
 282 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 283         pgd_t *pgd;
 284         pud_t *pud;
 285         pmd_t *pmd;
 286         pte_t *pte;
 287         int i, j, k;
 288         unsigned long vaddr;
 289
 290         vaddr = start;
 291         i = __pgd_offset(vaddr);
 292         j = __pud_offset(vaddr);
 293         k = __pmd_offset(vaddr);
 294         pgd = pgd_base + i;
 295
 296         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 297                 pud = (pud_t *)pgd;
 298                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 299                         pmd = (pmd_t *)pud;
 300                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 301                                 if (pmd_none(*pmd)) {
 302                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 303                                         set_pmd(pmd, __pmd((unsigned long)pte));
 304                                         if (pte != pte_offset_kernel(pmd, 0))
 305                                                 BUG();
 306                                 }
 307                                 vaddr += PMD_SIZE;
 308                         }
 309                         k = 0;
 310                 }
 311                 j = 0;
 312         }
 313 #endif
 314 }
 315
 316 #ifndef CONFIG_NEED_MULTIPLE_NODES
 317 static int __init page_is_ram(unsigned long pagenr)
 318 {
 319         int i;
 320
 321         for (i = 0; i < boot_mem_map.nr_map; i++) {
 322                 unsigned long addr, end;
 323
 324                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 325                         /* not usable memory */
 326                         continue;
 327
 328                 addr = PFN_UP(boot_mem_map.map[i].addr);
 329                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 330                                boot_mem_map.map[i].size);
 331
 332                 if (pagenr >= addr && pagenr < end)
 333                         return 1;
 334         }
 335
 336         return 0;
 337 }
 338
 339 void __init paging_init(void)
 340 {
 341         unsigned long zones_size[MAX_NR_ZONES] = { 0, };
 342 #ifndef CONFIG_FLATMEM
 343         unsigned long zholes_size[MAX_NR_ZONES] = { 0, };
 344         unsigned long i, j, pfn;
 345 #endif
 346
 347         pagetable_init();
 348
 349 #ifdef CONFIG_HIGHMEM
 350         kmap_init();
 351 #endif
 352         kmap_coherent_init();
 353
 354 #ifdef CONFIG_ZONE_DMA
 355         if (min_low_pfn < MAX_DMA_PFN && MAX_DMA_PFN <= max_low_pfn) {
 356                 zones_size[ZONE_DMA] = MAX_DMA_PFN - min_low_pfn;
 357                 zones_size[ZONE_NORMAL] = max_low_pfn - MAX_DMA_PFN;
 358         } else if (max_low_pfn < MAX_DMA_PFN)
 359                 zones_size[ZONE_DMA] = max_low_pfn - min_low_pfn;
 360         else
 361 #endif
 362         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 363
 364 #ifdef CONFIG_HIGHMEM
 365         zones_size[ZONE_HIGHMEM] = highend_pfn - highstart_pfn;
 366
 367         if (cpu_has_dc_aliases && zones_size[ZONE_HIGHMEM]) {
 368                 printk(KERN_WARNING "This processor doesn't support highmem."
 369                        " %ldk highmem ignored\n", zones_size[ZONE_HIGHMEM]);
 370                 zones_size[ZONE_HIGHMEM] = 0;
 371         }
 372 #endif
 373
 374 #ifdef CONFIG_FLATMEM
 375         free_area_init(zones_size);
 376 #else
 377         pfn = min_low_pfn;
 378         for (i = 0; i < MAX_NR_ZONES; i++)
 379                 for (j = 0; j < zones_size[i]; j++, pfn++)
 380                         if (!page_is_ram(pfn))
 381                                 zholes_size[i]++;
 382         free_area_init_node(0, NODE_DATA(0), zones_size, 0, zholes_size);
 383 #endif
 384 }
 385
 386 static struct kcore_list kcore_mem, kcore_vmalloc;
 387 #ifdef CONFIG_64BIT
 388 static struct kcore_list kcore_kseg0;
 389 #endif
 390
 391 void __init mem_init(void)
 392 {
 393         unsigned long codesize, reservedpages, datasize, initsize;
 394         unsigned long tmp, ram;
 395
 396 #ifdef CONFIG_HIGHMEM
 397 #ifdef CONFIG_DISCONTIGMEM
 398 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 399 #endif
 400         max_mapnr = highend_pfn;
 401 #else
 402         max_mapnr = max_low_pfn;
 403 #endif
 404         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 405
 406         totalram_pages += free_all_bootmem();
 407         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 408
 409         reservedpages = ram = 0;
 410         for (tmp = 0; tmp < max_low_pfn; tmp++)
 411                 if (page_is_ram(tmp)) {
 412                         ram++;
 413                         if (PageReserved(pfn_to_page(tmp)))
 414                                 reservedpages++;
 415                 }
 416         num_physpages = ram;
 417
 418 #ifdef CONFIG_HIGHMEM
 419         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 420                 struct page *page = mem_map + tmp;
 421
 422                 if (!page_is_ram(tmp)) {
 423                         SetPageReserved(page);
 424                         continue;
 425                 }
 426                 ClearPageReserved(page);
 427                 init_page_count(page);
 428                 __free_page(page);
 429                 totalhigh_pages++;
 430         }
 431         totalram_pages += totalhigh_pages;
 432         num_physpages += totalhigh_pages;
 433 #endif
 434
 435         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 436         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 437         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 438
 439 #ifdef CONFIG_64BIT
 440         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 441                 /* The -4 is a hack so that user tools don't have to handle
 442                    the overflow.  */
 443                 kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
 444 #endif
 445         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 446         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 447                    VMALLOC_END-VMALLOC_START);
 448
 449         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 450                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 451                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 452                ram << (PAGE_SHIFT-10),
 453                codesize >> 10,
 454                reservedpages << (PAGE_SHIFT-10),
 455                datasize >> 10,
 456                initsize >> 10,
 457                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 458 }
 459 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 460
 461 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 462 {
 463         unsigned long pfn;
 464
 465         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 466                 struct page *page = pfn_to_page(pfn);
 467                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 468
 469                 ClearPageReserved(page);
 470                 init_page_count(page);
 471                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 472                 __free_page(page);
 473                 totalram_pages++;
 474         }
 475         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 476 }
 477
 478 #ifdef CONFIG_BLK_DEV_INITRD
 479 void free_initrd_mem(unsigned long start, unsigned long end)
 480 {
 481         free_init_pages("initrd memory",
 482                         virt_to_phys((void *)start),
 483                         virt_to_phys((void *)end));
 484 }
 485 #endif
 486
 487 void free_initmem(void)
 488 {
 489         prom_free_prom_memory();
 490         free_init_pages("unused kernel memory",
 491                         __pa_symbol(&__init_begin),
 492                         __pa_symbol(&__init_end));
 493 }
 494
 495 unsigned long pgd_current[NR_CPUS];
 496 /*
 497  * On 64-bit we've got three-level pagetables with a slightly
 498  * different layout ...
 499  */
 500 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
 501 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 502 #ifdef CONFIG_64BIT
 503 #ifdef MODULE_START
 504 pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 505 #endif
 506 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 507 #endif
 508 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);