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 #include <asm/vdso.h>
  50
  51 #include "mmu_decl.h"
  52
  53 #ifndef CPU_FTR_COHERENT_ICACHE
  54 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  55 #define CPU_FTR_NOEXECUTE       0
  56 #endif
  57
  58 int init_bootmem_done;
  59 int mem_init_done;
  60 unsigned long memory_limit;
  61
  62 extern void hash_preload(struct mm_struct *mm, unsigned long ea,
  63                          unsigned long access, unsigned long trap);
  64
  65 /*
  66  * This is called by /dev/mem to know if a given address has to
  67  * be mapped non-cacheable or not
  68  */
  69 int page_is_ram(unsigned long pfn)
  70 {
  71         unsigned long paddr = (pfn << PAGE_SHIFT);
  72
  73 #ifndef CONFIG_PPC64    /* XXX for now */
  74         return paddr < __pa(high_memory);
  75 #else
  76         int i;
  77         for (i=0; i < lmb.memory.cnt; i++) {
  78                 unsigned long base;
  79
  80                 base = lmb.memory.region[i].base;
  81
  82                 if ((paddr >= base) &&
  83                         (paddr < (base + lmb.memory.region[i].size))) {
  84                         return 1;
  85                 }
  86         }
  87
  88         return 0;
  89 #endif
  90 }
  91 EXPORT_SYMBOL(page_is_ram);
  92
  93 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  94                               unsigned long size, pgprot_t vma_prot)
  95 {
  96         if (ppc_md.phys_mem_access_prot)
  97                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  98
  99         if (!page_is_ram(pfn))
 100                 vma_prot = __pgprot(pgprot_val(vma_prot)
 101                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
 102         return vma_prot;
 103 }
 104 EXPORT_SYMBOL(phys_mem_access_prot);
 105
 106 #ifdef CONFIG_MEMORY_HOTPLUG
 107
 108 void online_page(struct page *page)
 109 {
 110         ClearPageReserved(page);
 111         init_page_count(page);
 112         __free_page(page);
 113         totalram_pages++;
 114         num_physpages++;
 115 }
 116
 117 int __devinit add_memory(u64 start, u64 size)
 118 {
 119         struct pglist_data *pgdata;
 120         struct zone *zone;
 121         int nid;
 122         unsigned long start_pfn = start >> PAGE_SHIFT;
 123         unsigned long nr_pages = size >> PAGE_SHIFT;
 124
 125         nid = hot_add_scn_to_nid(start);
 126         pgdata = NODE_DATA(nid);
 127
 128         start = __va(start);
 129         create_section_mapping(start, start + size);
 130
 131         /* this should work for most non-highmem platforms */
 132         zone = pgdata->node_zones;
 133
 134         return __add_pages(zone, start_pfn, nr_pages);
 135
 136         return 0;
 137 }
 138
 139 /*
 140  * First pass at this code will check to determine if the remove
 141  * request is within the RMO.  Do not allow removal within the RMO.
 142  */
 143 int __devinit remove_memory(u64 start, u64 size)
 144 {
 145         struct zone *zone;
 146         unsigned long start_pfn, end_pfn, nr_pages;
 147
 148         start_pfn = start >> PAGE_SHIFT;
 149         nr_pages = size >> PAGE_SHIFT;
 150         end_pfn = start_pfn + nr_pages;
 151
 152         printk("%s(): Attempting to remove memoy in range "
 153                         "%lx to %lx\n", __func__, start, start+size);
 154         /*
 155          * check for range within RMO
 156          */
 157         zone = page_zone(pfn_to_page(start_pfn));
 158
 159         printk("%s(): memory will be removed from "
 160                         "the %s zone\n", __func__, zone->name);
 161
 162         /*
 163          * not handling removing memory ranges that
 164          * overlap multiple zones yet
 165          */
 166         if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
 167                 goto overlap;
 168
 169         /* make sure it is NOT in RMO */
 170         if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
 171                 printk("%s(): range to be removed must NOT be in RMO!\n",
 172                         __func__);
 173                 goto in_rmo;
 174         }
 175
 176         return __remove_pages(zone, start_pfn, nr_pages);
 177
 178 overlap:
 179         printk("%s(): memory range to be removed overlaps "
 180                 "multiple zones!!!\n", __func__);
 181 in_rmo:
 182         return -1;
 183 }
 184 #endif /* CONFIG_MEMORY_HOTPLUG */
 185
 186 void show_mem(void)
 187 {
 188         unsigned long total = 0, reserved = 0;
 189         unsigned long shared = 0, cached = 0;
 190         unsigned long highmem = 0;
 191         struct page *page;
 192         pg_data_t *pgdat;
 193         unsigned long i;
 194
 195         printk("Mem-info:\n");
 196         show_free_areas();
 197         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 198         for_each_pgdat(pgdat) {
 199                 unsigned long flags;
 200                 pgdat_resize_lock(pgdat, &flags);
 201                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 202                         if (!pfn_valid(pgdat->node_start_pfn + i))
 203                                 continue;
 204                         page = pgdat_page_nr(pgdat, i);
 205                         total++;
 206                         if (PageHighMem(page))
 207                                 highmem++;
 208                         if (PageReserved(page))
 209                                 reserved++;
 210                         else if (PageSwapCache(page))
 211                                 cached++;
 212                         else if (page_count(page))
 213                                 shared += page_count(page) - 1;
 214                 }
 215                 pgdat_resize_unlock(pgdat, &flags);
 216         }
 217         printk("%ld pages of RAM\n", total);
 218 #ifdef CONFIG_HIGHMEM
 219         printk("%ld pages of HIGHMEM\n", highmem);
 220 #endif
 221         printk("%ld reserved pages\n", reserved);
 222         printk("%ld pages shared\n", shared);
 223         printk("%ld pages swap cached\n", cached);
 224 }
 225
 226 /*
 227  * Initialize the bootmem system and give it all the memory we
 228  * have available.  If we are using highmem, we only put the
 229  * lowmem into the bootmem system.
 230  */
 231 #ifndef CONFIG_NEED_MULTIPLE_NODES
 232 void __init do_init_bootmem(void)
 233 {
 234         unsigned long i;
 235         unsigned long start, bootmap_pages;
 236         unsigned long total_pages;
 237         int boot_mapsize;
 238
 239         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 240 #ifdef CONFIG_HIGHMEM
 241         total_pages = total_lowmem >> PAGE_SHIFT;
 242 #endif
 243
 244         /*
 245          * Find an area to use for the bootmem bitmap.  Calculate the size of
 246          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 247          * Add 1 additional page in case the address isn't page-aligned.
 248          */
 249         bootmap_pages = bootmem_bootmap_pages(total_pages);
 250
 251         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 252         BUG_ON(!start);
 253
 254         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 255
 256         /* Add all physical memory to the bootmem map, mark each area
 257          * present.
 258          */
 259         for (i = 0; i < lmb.memory.cnt; i++) {
 260                 unsigned long base = lmb.memory.region[i].base;
 261                 unsigned long size = lmb_size_bytes(&lmb.memory, i);
 262 #ifdef CONFIG_HIGHMEM
 263                 if (base >= total_lowmem)
 264                         continue;
 265                 if (base + size > total_lowmem)
 266                         size = total_lowmem - base;
 267 #endif
 268                 free_bootmem(base, size);
 269         }
 270
 271         /* reserve the sections we're already using */
 272         for (i = 0; i < lmb.reserved.cnt; i++)
 273                 reserve_bootmem(lmb.reserved.region[i].base,
 274                                 lmb_size_bytes(&lmb.reserved, i));
 275
 276         /* XXX need to clip this if using highmem? */
 277         for (i = 0; i < lmb.memory.cnt; i++)
 278                 memory_present(0, lmb_start_pfn(&lmb.memory, i),
 279                                lmb_end_pfn(&lmb.memory, i));
 280         init_bootmem_done = 1;
 281 }
 282
 283 /*
 284  * paging_init() sets up the page tables - in fact we've already done this.
 285  */
 286 void __init paging_init(void)
 287 {
 288         unsigned long zones_size[MAX_NR_ZONES];
 289         unsigned long zholes_size[MAX_NR_ZONES];
 290         unsigned long total_ram = lmb_phys_mem_size();
 291         unsigned long top_of_ram = lmb_end_of_DRAM();
 292
 293 #ifdef CONFIG_HIGHMEM
 294         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 295         pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
 296                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 297         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 298         kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
 299                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
 300         kmap_prot = PAGE_KERNEL;
 301 #endif /* CONFIG_HIGHMEM */
 302
 303         printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 304                top_of_ram, total_ram);
 305         printk(KERN_INFO "Memory hole size: %ldMB\n",
 306                (top_of_ram - total_ram) >> 20);
 307         /*
 308          * All pages are DMA-able so we put them all in the DMA zone.
 309          */
 310         memset(zones_size, 0, sizeof(zones_size));
 311         memset(zholes_size, 0, sizeof(zholes_size));
 312
 313         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 314         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 315
 316 #ifdef CONFIG_HIGHMEM
 317         zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 318         zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
 319         zholes_size[ZONE_HIGHMEM] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 320 #else
 321         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 322         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 323 #endif /* CONFIG_HIGHMEM */
 324
 325         free_area_init_node(0, NODE_DATA(0), zones_size,
 326                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 327 }
 328 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 329
 330 void __init mem_init(void)
 331 {
 332 #ifdef CONFIG_NEED_MULTIPLE_NODES
 333         int nid;
 334 #endif
 335         pg_data_t *pgdat;
 336         unsigned long i;
 337         struct page *page;
 338         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 339
 340         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 341         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 342
 343 #ifdef CONFIG_NEED_MULTIPLE_NODES
 344         for_each_online_node(nid) {
 345                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 346                         printk("freeing bootmem node %x\n", nid);
 347                         totalram_pages +=
 348                                 free_all_bootmem_node(NODE_DATA(nid));
 349                 }
 350         }
 351 #else
 352         max_mapnr = max_pfn;
 353         totalram_pages += free_all_bootmem();
 354 #endif
 355         for_each_pgdat(pgdat) {
 356                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 357                         if (!pfn_valid(pgdat->node_start_pfn + i))
 358                                 continue;
 359                         page = pgdat_page_nr(pgdat, i);
 360                         if (PageReserved(page))
 361                                 reservedpages++;
 362                 }
 363         }
 364
 365         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 366         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 367         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 368         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 369
 370 #ifdef CONFIG_HIGHMEM
 371         {
 372                 unsigned long pfn, highmem_mapnr;
 373
 374                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 375                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 376                         struct page *page = pfn_to_page(pfn);
 377
 378                         ClearPageReserved(page);
 379                         init_page_count(page);
 380                         __free_page(page);
 381                         totalhigh_pages++;
 382                 }
 383                 totalram_pages += totalhigh_pages;
 384                 printk(KERN_INFO "High memory: %luk\n",
 385                        totalhigh_pages << (PAGE_SHIFT-10));
 386         }
 387 #endif /* CONFIG_HIGHMEM */
 388
 389         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 390                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 391                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 392                 num_physpages << (PAGE_SHIFT-10),
 393                 codesize >> 10,
 394                 reservedpages << (PAGE_SHIFT-10),
 395                 datasize >> 10,
 396                 bsssize >> 10,
 397                 initsize >> 10);
 398
 399         mem_init_done = 1;
 400
 401         /* Initialize the vDSO */
 402         vdso_init();
 403 }
 404
 405 /*
 406  * This is called when a page has been modified by the kernel.
 407  * It just marks the page as not i-cache clean.  We do the i-cache
 408  * flush later when the page is given to a user process, if necessary.
 409  */
 410 void flush_dcache_page(struct page *page)
 411 {
 412         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 413                 return;
 414         /* avoid an atomic op if possible */
 415         if (test_bit(PG_arch_1, &page->flags))
 416                 clear_bit(PG_arch_1, &page->flags);
 417 }
 418 EXPORT_SYMBOL(flush_dcache_page);
 419
 420 void flush_dcache_icache_page(struct page *page)
 421 {
 422 #ifdef CONFIG_BOOKE
 423         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 424         __flush_dcache_icache(start);
 425         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 426 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 427         /* On 8xx there is no need to kmap since highmem is not supported */
 428         __flush_dcache_icache(page_address(page));
 429 #else
 430         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 431 #endif
 432
 433 }
 434 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 435 {
 436         clear_page(page);
 437
 438         /*
 439          * We shouldnt have to do this, but some versions of glibc
 440          * require it (ld.so assumes zero filled pages are icache clean)
 441          * - Anton
 442          */
 443         flush_dcache_page(pg);
 444 }
 445 EXPORT_SYMBOL(clear_user_page);
 446
 447 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 448                     struct page *pg)
 449 {
 450         copy_page(vto, vfrom);
 451
 452         /*
 453          * We should be able to use the following optimisation, however
 454          * there are two problems.
 455          * Firstly a bug in some versions of binutils meant PLT sections
 456          * were not marked executable.
 457          * Secondly the first word in the GOT section is blrl, used
 458          * to establish the GOT address. Until recently the GOT was
 459          * not marked executable.
 460          * - Anton
 461          */
 462 #if 0
 463         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 464                 return;
 465 #endif
 466
 467         flush_dcache_page(pg);
 468 }
 469
 470 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 471                              unsigned long addr, int len)
 472 {
 473         unsigned long maddr;
 474
 475         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 476         flush_icache_range(maddr, maddr + len);
 477         kunmap(page);
 478 }
 479 EXPORT_SYMBOL(flush_icache_user_range);
 480
 481 /*
 482  * This is called at the end of handling a user page fault, when the
 483  * fault has been handled by updating a PTE in the linux page tables.
 484  * We use it to preload an HPTE into the hash table corresponding to
 485  * the updated linux PTE.
 486  *
 487  * This must always be called with the pte lock held.
 488  */
 489 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 490                       pte_t pte)
 491 {
 492 #ifdef CONFIG_PPC_STD_MMU
 493         unsigned long access = 0, trap;
 494 #endif
 495         unsigned long pfn = pte_pfn(pte);
 496
 497         /* handle i-cache coherency */
 498         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 499             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 500             pfn_valid(pfn)) {
 501                 struct page *page = pfn_to_page(pfn);
 502                 if (!PageReserved(page)
 503                     && !test_bit(PG_arch_1, &page->flags)) {
 504                         if (vma->vm_mm == current->active_mm) {
 505 #ifdef CONFIG_8xx
 506                         /* On 8xx, cache control instructions (particularly
 507                          * "dcbst" from flush_dcache_icache) fault as write
 508                          * operation if there is an unpopulated TLB entry
 509                          * for the address in question. To workaround that,
 510                          * we invalidate the TLB here, thus avoiding dcbst
 511                          * misbehaviour.
 512                          */
 513                                 _tlbie(address);
 514 #endif
 515                                 __flush_dcache_icache((void *) address);
 516                         } else
 517                                 flush_dcache_icache_page(page);
 518                         set_bit(PG_arch_1, &page->flags);
 519                 }
 520         }
 521
 522 #ifdef CONFIG_PPC_STD_MMU
 523         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 524         if (!pte_young(pte) || address >= TASK_SIZE)
 525                 return;
 526
 527         /* We try to figure out if we are coming from an instruction
 528          * access fault and pass that down to __hash_page so we avoid
 529          * double-faulting on execution of fresh text. We have to test
 530          * for regs NULL since init will get here first thing at boot
 531          *
 532          * We also avoid filling the hash if not coming from a fault
 533          */
 534         if (current->thread.regs == NULL)
 535                 return;
 536         trap = TRAP(current->thread.regs);
 537         if (trap == 0x400)
 538                 access |= _PAGE_EXEC;
 539         else if (trap != 0x300)
 540                 return;
 541         hash_preload(vma->vm_mm, address, access, trap);
 542 #endif /* CONFIG_PPC_STD_MMU */
 543 }