git.oblomov.eu Git - linux-2.6/blob - arch/powerpc/mm/mem.c

   1 /*
   2  *  PowerPC version
   3  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   4  *
   5  *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
   6  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
   7  *    Copyright (C) 1996 Paul Mackerras
   8  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
   9  *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
  10  *
  11  *  Derived from "arch/i386/mm/init.c"
  12  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  13  *
  14  *  This program is free software; you can redistribute it and/or
  15  *  modify it under the terms of the GNU General Public License
  16  *  as published by the Free Software Foundation; either version
  17  *  2 of the License, or (at your option) any later version.
  18  *
  19  */
  20
  21 #include <linux/config.h>
  22 #include <linux/module.h>
  23 #include <linux/sched.h>
  24 #include <linux/kernel.h>
  25 #include <linux/errno.h>
  26 #include <linux/string.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/stddef.h>
  30 #include <linux/init.h>
  31 #include <linux/bootmem.h>
  32 #include <linux/highmem.h>
  33 #include <linux/initrd.h>
  34 #include <linux/pagemap.h>
  35
  36 #include <asm/pgalloc.h>
  37 #include <asm/prom.h>
  38 #include <asm/io.h>
  39 #include <asm/mmu_context.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/mmu.h>
  42 #include <asm/smp.h>
  43 #include <asm/machdep.h>
  44 #include <asm/btext.h>
  45 #include <asm/tlb.h>
  46 #include <asm/prom.h>
  47 #include <asm/lmb.h>
  48 #include <asm/sections.h>
  49 #ifdef CONFIG_PPC64
  50 #include <asm/vdso.h>
  51 #endif
  52
  53 #include "mmu_decl.h"
  54
  55 #ifndef CPU_FTR_COHERENT_ICACHE
  56 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  57 #define CPU_FTR_NOEXECUTE       0
  58 #endif
  59
  60 int init_bootmem_done;
  61 int mem_init_done;
  62
  63 /*
  64  * This is called by /dev/mem to know if a given address has to
  65  * be mapped non-cacheable or not
  66  */
  67 int page_is_ram(unsigned long pfn)
  68 {
  69         unsigned long paddr = (pfn << PAGE_SHIFT);
  70
  71 #ifndef CONFIG_PPC64    /* XXX for now */
  72         return paddr < __pa(high_memory);
  73 #else
  74         int i;
  75         for (i=0; i < lmb.memory.cnt; i++) {
  76                 unsigned long base;
  77
  78                 base = lmb.memory.region[i].base;
  79
  80                 if ((paddr >= base) &&
  81                         (paddr < (base + lmb.memory.region[i].size))) {
  82                         return 1;
  83                 }
  84         }
  85
  86         return 0;
  87 #endif
  88 }
  89 EXPORT_SYMBOL(page_is_ram);
  90
  91 pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
  92                               unsigned long size, pgprot_t vma_prot)
  93 {
  94         if (ppc_md.phys_mem_access_prot)
  95                 return ppc_md.phys_mem_access_prot(file, addr, size, vma_prot);
  96
  97         if (!page_is_ram(addr >> PAGE_SHIFT))
  98                 vma_prot = __pgprot(pgprot_val(vma_prot)
  99                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
 100         return vma_prot;
 101 }
 102 EXPORT_SYMBOL(phys_mem_access_prot);
 103
 104 void show_mem(void)
 105 {
 106         unsigned long total = 0, reserved = 0;
 107         unsigned long shared = 0, cached = 0;
 108         unsigned long highmem = 0;
 109         struct page *page;
 110         pg_data_t *pgdat;
 111         unsigned long i;
 112
 113         printk("Mem-info:\n");
 114         show_free_areas();
 115         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 116         for_each_pgdat(pgdat) {
 117                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 118                         page = pgdat_page_nr(pgdat, i);
 119                         total++;
 120                         if (PageHighMem(page))
 121                                 highmem++;
 122                         if (PageReserved(page))
 123                                 reserved++;
 124                         else if (PageSwapCache(page))
 125                                 cached++;
 126                         else if (page_count(page))
 127                                 shared += page_count(page) - 1;
 128                 }
 129         }
 130         printk("%ld pages of RAM\n", total);
 131 #ifdef CONFIG_HIGHMEM
 132         printk("%ld pages of HIGHMEM\n", highmem);
 133 #endif
 134         printk("%ld reserved pages\n", reserved);
 135         printk("%ld pages shared\n", shared);
 136         printk("%ld pages swap cached\n", cached);
 137 }
 138
 139 /*
 140  * Initialize the bootmem system and give it all the memory we
 141  * have available.  If we are using highmem, we only put the
 142  * lowmem into the bootmem system.
 143  */
 144 #ifndef CONFIG_NEED_MULTIPLE_NODES
 145 void __init do_init_bootmem(void)
 146 {
 147         unsigned long i;
 148         unsigned long start, bootmap_pages;
 149         unsigned long total_pages;
 150         int boot_mapsize;
 151
 152         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 153 #ifdef CONFIG_HIGHMEM
 154         total_pages = total_lowmem >> PAGE_SHIFT;
 155 #endif
 156
 157         /*
 158          * Find an area to use for the bootmem bitmap.  Calculate the size of
 159          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 160          * Add 1 additional page in case the address isn't page-aligned.
 161          */
 162         bootmap_pages = bootmem_bootmap_pages(total_pages);
 163
 164         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 165         BUG_ON(!start);
 166
 167         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 168
 169         /* Add all physical memory to the bootmem map, mark each area
 170          * present.
 171          */
 172         for (i = 0; i < lmb.memory.cnt; i++) {
 173                 unsigned long base = lmb.memory.region[i].base;
 174                 unsigned long size = lmb_size_bytes(&lmb.memory, i);
 175 #ifdef CONFIG_HIGHMEM
 176                 if (base >= total_lowmem)
 177                         continue;
 178                 if (base + size > total_lowmem)
 179                         size = total_lowmem - base;
 180 #endif
 181                 free_bootmem(base, size);
 182         }
 183
 184         /* reserve the sections we're already using */
 185         for (i = 0; i < lmb.reserved.cnt; i++)
 186                 reserve_bootmem(lmb.reserved.region[i].base,
 187                                 lmb_size_bytes(&lmb.reserved, i));
 188
 189         /* XXX need to clip this if using highmem? */
 190         for (i = 0; i < lmb.memory.cnt; i++)
 191                 memory_present(0, lmb_start_pfn(&lmb.memory, i),
 192                                lmb_end_pfn(&lmb.memory, i));
 193         init_bootmem_done = 1;
 194 }
 195
 196 /*
 197  * paging_init() sets up the page tables - in fact we've already done this.
 198  */
 199 void __init paging_init(void)
 200 {
 201         unsigned long zones_size[MAX_NR_ZONES];
 202         unsigned long zholes_size[MAX_NR_ZONES];
 203         unsigned long total_ram = lmb_phys_mem_size();
 204         unsigned long top_of_ram = lmb_end_of_DRAM();
 205
 206 #ifdef CONFIG_HIGHMEM
 207         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 208         pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
 209                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 210         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 211         kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
 212                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
 213         kmap_prot = PAGE_KERNEL;
 214 #endif /* CONFIG_HIGHMEM */
 215
 216         printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 217                top_of_ram, total_ram);
 218         printk(KERN_INFO "Memory hole size: %ldMB\n",
 219                (top_of_ram - total_ram) >> 20);
 220         /*
 221          * All pages are DMA-able so we put them all in the DMA zone.
 222          */
 223         memset(zones_size, 0, sizeof(zones_size));
 224         memset(zholes_size, 0, sizeof(zholes_size));
 225
 226         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 227         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 228
 229 #ifdef CONFIG_HIGHMEM
 230         zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 231         zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
 232         zholes_size[ZONE_HIGHMEM] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 233 #else
 234         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 235         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 236 #endif /* CONFIG_HIGHMEM */
 237
 238         free_area_init_node(0, NODE_DATA(0), zones_size,
 239                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 240 }
 241 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 242
 243 void __init mem_init(void)
 244 {
 245 #ifdef CONFIG_NEED_MULTIPLE_NODES
 246         int nid;
 247 #endif
 248         pg_data_t *pgdat;
 249         unsigned long i;
 250         struct page *page;
 251         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 252
 253         num_physpages = max_pfn;        /* RAM is assumed contiguous */
 254         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 255
 256 #ifdef CONFIG_NEED_MULTIPLE_NODES
 257         for_each_online_node(nid) {
 258                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 259                         printk("freeing bootmem node %x\n", nid);
 260                         totalram_pages +=
 261                                 free_all_bootmem_node(NODE_DATA(nid));
 262                 }
 263         }
 264 #else
 265         max_mapnr = num_physpages;
 266         totalram_pages += free_all_bootmem();
 267 #endif
 268         for_each_pgdat(pgdat) {
 269                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 270                         page = pgdat_page_nr(pgdat, i);
 271                         if (PageReserved(page))
 272                                 reservedpages++;
 273                 }
 274         }
 275
 276         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 277         datasize = (unsigned long)&__init_begin - (unsigned long)&_sdata;
 278         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 279         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 280
 281 #ifdef CONFIG_HIGHMEM
 282         {
 283                 unsigned long pfn, highmem_mapnr;
 284
 285                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 286                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 287                         struct page *page = pfn_to_page(pfn);
 288
 289                         ClearPageReserved(page);
 290                         set_page_count(page, 1);
 291                         __free_page(page);
 292                         totalhigh_pages++;
 293                 }
 294                 totalram_pages += totalhigh_pages;
 295                 printk(KERN_INFO "High memory: %luk\n",
 296                        totalhigh_pages << (PAGE_SHIFT-10));
 297         }
 298 #endif /* CONFIG_HIGHMEM */
 299
 300         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 301                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 302                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 303                 num_physpages << (PAGE_SHIFT-10),
 304                 codesize >> 10,
 305                 reservedpages << (PAGE_SHIFT-10),
 306                 datasize >> 10,
 307                 bsssize >> 10,
 308                 initsize >> 10);
 309
 310         mem_init_done = 1;
 311
 312 #ifdef CONFIG_PPC64
 313         /* Initialize the vDSO */
 314         vdso_init();
 315 #endif
 316 }
 317
 318 /*
 319  * This is called when a page has been modified by the kernel.
 320  * It just marks the page as not i-cache clean.  We do the i-cache
 321  * flush later when the page is given to a user process, if necessary.
 322  */
 323 void flush_dcache_page(struct page *page)
 324 {
 325         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 326                 return;
 327         /* avoid an atomic op if possible */
 328         if (test_bit(PG_arch_1, &page->flags))
 329                 clear_bit(PG_arch_1, &page->flags);
 330 }
 331 EXPORT_SYMBOL(flush_dcache_page);
 332
 333 void flush_dcache_icache_page(struct page *page)
 334 {
 335 #ifdef CONFIG_BOOKE
 336         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 337         __flush_dcache_icache(start);
 338         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 339 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 340         /* On 8xx there is no need to kmap since highmem is not supported */
 341         __flush_dcache_icache(page_address(page));
 342 #else
 343         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 344 #endif
 345
 346 }
 347 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 348 {
 349         clear_page(page);
 350
 351         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 352                 return;
 353         /*
 354          * We shouldnt have to do this, but some versions of glibc
 355          * require it (ld.so assumes zero filled pages are icache clean)
 356          * - Anton
 357          */
 358
 359         /* avoid an atomic op if possible */
 360         if (test_bit(PG_arch_1, &pg->flags))
 361                 clear_bit(PG_arch_1, &pg->flags);
 362 }
 363 EXPORT_SYMBOL(clear_user_page);
 364
 365 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 366                     struct page *pg)
 367 {
 368         copy_page(vto, vfrom);
 369
 370         /*
 371          * We should be able to use the following optimisation, however
 372          * there are two problems.
 373          * Firstly a bug in some versions of binutils meant PLT sections
 374          * were not marked executable.
 375          * Secondly the first word in the GOT section is blrl, used
 376          * to establish the GOT address. Until recently the GOT was
 377          * not marked executable.
 378          * - Anton
 379          */
 380 #if 0
 381         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 382                 return;
 383 #endif
 384
 385         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 386                 return;
 387
 388         /* avoid an atomic op if possible */
 389         if (test_bit(PG_arch_1, &pg->flags))
 390                 clear_bit(PG_arch_1, &pg->flags);
 391 }
 392
 393 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 394                              unsigned long addr, int len)
 395 {
 396         unsigned long maddr;
 397
 398         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 399         flush_icache_range(maddr, maddr + len);
 400         kunmap(page);
 401 }
 402 EXPORT_SYMBOL(flush_icache_user_range);
 403
 404 /*
 405  * This is called at the end of handling a user page fault, when the
 406  * fault has been handled by updating a PTE in the linux page tables.
 407  * We use it to preload an HPTE into the hash table corresponding to
 408  * the updated linux PTE.
 409  *
 410  * This must always be called with the mm->page_table_lock held
 411  */
 412 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 413                       pte_t pte)
 414 {
 415         /* handle i-cache coherency */
 416         unsigned long pfn = pte_pfn(pte);
 417 #ifdef CONFIG_PPC32
 418         pmd_t *pmd;
 419 #else
 420         unsigned long vsid;
 421         void *pgdir;
 422         pte_t *ptep;
 423         int local = 0;
 424         cpumask_t tmp;
 425         unsigned long flags;
 426 #endif
 427
 428         /* handle i-cache coherency */
 429         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 430             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 431             pfn_valid(pfn)) {
 432                 struct page *page = pfn_to_page(pfn);
 433                 if (!PageReserved(page)
 434                     && !test_bit(PG_arch_1, &page->flags)) {
 435                         if (vma->vm_mm == current->active_mm) {
 436 #ifdef CONFIG_8xx
 437                         /* On 8xx, cache control instructions (particularly
 438                          * "dcbst" from flush_dcache_icache) fault as write
 439                          * operation if there is an unpopulated TLB entry
 440                          * for the address in question. To workaround that,
 441                          * we invalidate the TLB here, thus avoiding dcbst
 442                          * misbehaviour.
 443                          */
 444                                 _tlbie(address);
 445 #endif
 446                                 __flush_dcache_icache((void *) address);
 447                         } else
 448                                 flush_dcache_icache_page(page);
 449                         set_bit(PG_arch_1, &page->flags);
 450                 }
 451         }
 452
 453 #ifdef CONFIG_PPC_STD_MMU
 454         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 455         if (!pte_young(pte) || address >= TASK_SIZE)
 456                 return;
 457 #ifdef CONFIG_PPC32
 458         if (Hash == 0)
 459                 return;
 460         pmd = pmd_offset(pgd_offset(vma->vm_mm, address), address);
 461         if (!pmd_none(*pmd))
 462                 add_hash_page(vma->vm_mm->context, address, pmd_val(*pmd));
 463 #else
 464         pgdir = vma->vm_mm->pgd;
 465         if (pgdir == NULL)
 466                 return;
 467
 468         ptep = find_linux_pte(pgdir, address);
 469         if (!ptep)
 470                 return;
 471
 472         vsid = get_vsid(vma->vm_mm->context.id, address);
 473
 474         local_irq_save(flags);
 475         tmp = cpumask_of_cpu(smp_processor_id());
 476         if (cpus_equal(vma->vm_mm->cpu_vm_mask, tmp))
 477                 local = 1;
 478
 479         __hash_page(address, 0, vsid, ptep, 0x300, local);
 480         local_irq_restore(flags);
 481 #endif
 482 #endif
 483 }