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 unsigned long memory_limit;
  63
  64 /*
  65  * This is called by /dev/mem to know if a given address has to
  66  * be mapped non-cacheable or not
  67  */
  68 int page_is_ram(unsigned long pfn)
  69 {
  70         unsigned long paddr = (pfn << PAGE_SHIFT);
  71
  72 #ifndef CONFIG_PPC64    /* XXX for now */
  73         return paddr < __pa(high_memory);
  74 #else
  75         int i;
  76         for (i=0; i < lmb.memory.cnt; i++) {
  77                 unsigned long base;
  78
  79                 base = lmb.memory.region[i].base;
  80
  81                 if ((paddr >= base) &&
  82                         (paddr < (base + lmb.memory.region[i].size))) {
  83                         return 1;
  84                 }
  85         }
  86
  87         return 0;
  88 #endif
  89 }
  90 EXPORT_SYMBOL(page_is_ram);
  91
  92 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  93                               unsigned long size, pgprot_t vma_prot)
  94 {
  95         if (ppc_md.phys_mem_access_prot)
  96                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  97
  98         if (!page_is_ram(pfn))
  99                 vma_prot = __pgprot(pgprot_val(vma_prot)
 100                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
 101         return vma_prot;
 102 }
 103 EXPORT_SYMBOL(phys_mem_access_prot);
 104
 105 #ifdef CONFIG_MEMORY_HOTPLUG
 106
 107 void online_page(struct page *page)
 108 {
 109         ClearPageReserved(page);
 110         free_cold_page(page);
 111         totalram_pages++;
 112         num_physpages++;
 113 }
 114
 115 /*
 116  * This works only for the non-NUMA case.  Later, we'll need a lookup
 117  * to convert from real physical addresses to nid, that doesn't use
 118  * pfn_to_nid().
 119  */
 120 int __devinit add_memory(u64 start, u64 size)
 121 {
 122         struct pglist_data *pgdata = NODE_DATA(0);
 123         struct zone *zone;
 124         unsigned long start_pfn = start >> PAGE_SHIFT;
 125         unsigned long nr_pages = size >> PAGE_SHIFT;
 126
 127         /* this should work for most non-highmem platforms */
 128         zone = pgdata->node_zones;
 129
 130         return __add_pages(zone, start_pfn, nr_pages);
 131
 132         return 0;
 133 }
 134
 135 /*
 136  * First pass at this code will check to determine if the remove
 137  * request is within the RMO.  Do not allow removal within the RMO.
 138  */
 139 int __devinit remove_memory(u64 start, u64 size)
 140 {
 141         struct zone *zone;
 142         unsigned long start_pfn, end_pfn, nr_pages;
 143
 144         start_pfn = start >> PAGE_SHIFT;
 145         nr_pages = size >> PAGE_SHIFT;
 146         end_pfn = start_pfn + nr_pages;
 147
 148         printk("%s(): Attempting to remove memoy in range "
 149                         "%lx to %lx\n", __func__, start, start+size);
 150         /*
 151          * check for range within RMO
 152          */
 153         zone = page_zone(pfn_to_page(start_pfn));
 154
 155         printk("%s(): memory will be removed from "
 156                         "the %s zone\n", __func__, zone->name);
 157
 158         /*
 159          * not handling removing memory ranges that
 160          * overlap multiple zones yet
 161          */
 162         if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
 163                 goto overlap;
 164
 165         /* make sure it is NOT in RMO */
 166         if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
 167                 printk("%s(): range to be removed must NOT be in RMO!\n",
 168                         __func__);
 169                 goto in_rmo;
 170         }
 171
 172         return __remove_pages(zone, start_pfn, nr_pages);
 173
 174 overlap:
 175         printk("%s(): memory range to be removed overlaps "
 176                 "multiple zones!!!\n", __func__);
 177 in_rmo:
 178         return -1;
 179 }
 180 #endif /* CONFIG_MEMORY_HOTPLUG */
 181
 182 void show_mem(void)
 183 {
 184         unsigned long total = 0, reserved = 0;
 185         unsigned long shared = 0, cached = 0;
 186         unsigned long highmem = 0;
 187         struct page *page;
 188         pg_data_t *pgdat;
 189         unsigned long i;
 190
 191         printk("Mem-info:\n");
 192         show_free_areas();
 193         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 194         for_each_pgdat(pgdat) {
 195                 unsigned long flags;
 196                 pgdat_resize_lock(pgdat, &flags);
 197                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 198                         page = pgdat_page_nr(pgdat, i);
 199                         total++;
 200                         if (PageHighMem(page))
 201                                 highmem++;
 202                         if (PageReserved(page))
 203                                 reserved++;
 204                         else if (PageSwapCache(page))
 205                                 cached++;
 206                         else if (page_count(page))
 207                                 shared += page_count(page) - 1;
 208                 }
 209                 pgdat_resize_unlock(pgdat, &flags);
 210         }
 211         printk("%ld pages of RAM\n", total);
 212 #ifdef CONFIG_HIGHMEM
 213         printk("%ld pages of HIGHMEM\n", highmem);
 214 #endif
 215         printk("%ld reserved pages\n", reserved);
 216         printk("%ld pages shared\n", shared);
 217         printk("%ld pages swap cached\n", cached);
 218 }
 219
 220 /*
 221  * Initialize the bootmem system and give it all the memory we
 222  * have available.  If we are using highmem, we only put the
 223  * lowmem into the bootmem system.
 224  */
 225 #ifndef CONFIG_NEED_MULTIPLE_NODES
 226 void __init do_init_bootmem(void)
 227 {
 228         unsigned long i;
 229         unsigned long start, bootmap_pages;
 230         unsigned long total_pages;
 231         int boot_mapsize;
 232
 233         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 234 #ifdef CONFIG_HIGHMEM
 235         total_pages = total_lowmem >> PAGE_SHIFT;
 236 #endif
 237
 238         /*
 239          * Find an area to use for the bootmem bitmap.  Calculate the size of
 240          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 241          * Add 1 additional page in case the address isn't page-aligned.
 242          */
 243         bootmap_pages = bootmem_bootmap_pages(total_pages);
 244
 245         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 246         BUG_ON(!start);
 247
 248         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 249
 250         /* Add all physical memory to the bootmem map, mark each area
 251          * present.
 252          */
 253         for (i = 0; i < lmb.memory.cnt; i++) {
 254                 unsigned long base = lmb.memory.region[i].base;
 255                 unsigned long size = lmb_size_bytes(&lmb.memory, i);
 256 #ifdef CONFIG_HIGHMEM
 257                 if (base >= total_lowmem)
 258                         continue;
 259                 if (base + size > total_lowmem)
 260                         size = total_lowmem - base;
 261 #endif
 262                 free_bootmem(base, size);
 263         }
 264
 265         /* reserve the sections we're already using */
 266         for (i = 0; i < lmb.reserved.cnt; i++)
 267                 reserve_bootmem(lmb.reserved.region[i].base,
 268                                 lmb_size_bytes(&lmb.reserved, i));
 269
 270         /* XXX need to clip this if using highmem? */
 271         for (i = 0; i < lmb.memory.cnt; i++)
 272                 memory_present(0, lmb_start_pfn(&lmb.memory, i),
 273                                lmb_end_pfn(&lmb.memory, i));
 274         init_bootmem_done = 1;
 275 }
 276
 277 /*
 278  * paging_init() sets up the page tables - in fact we've already done this.
 279  */
 280 void __init paging_init(void)
 281 {
 282         unsigned long zones_size[MAX_NR_ZONES];
 283         unsigned long zholes_size[MAX_NR_ZONES];
 284         unsigned long total_ram = lmb_phys_mem_size();
 285         unsigned long top_of_ram = lmb_end_of_DRAM();
 286
 287 #ifdef CONFIG_HIGHMEM
 288         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 289         pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
 290                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 291         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 292         kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
 293                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
 294         kmap_prot = PAGE_KERNEL;
 295 #endif /* CONFIG_HIGHMEM */
 296
 297         printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 298                top_of_ram, total_ram);
 299         printk(KERN_INFO "Memory hole size: %ldMB\n",
 300                (top_of_ram - total_ram) >> 20);
 301         /*
 302          * All pages are DMA-able so we put them all in the DMA zone.
 303          */
 304         memset(zones_size, 0, sizeof(zones_size));
 305         memset(zholes_size, 0, sizeof(zholes_size));
 306
 307         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 308         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 309
 310 #ifdef CONFIG_HIGHMEM
 311         zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 312         zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
 313         zholes_size[ZONE_HIGHMEM] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 314 #else
 315         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 316         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 317 #endif /* CONFIG_HIGHMEM */
 318
 319         free_area_init_node(0, NODE_DATA(0), zones_size,
 320                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 321 }
 322 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 323
 324 void __init mem_init(void)
 325 {
 326 #ifdef CONFIG_NEED_MULTIPLE_NODES
 327         int nid;
 328 #endif
 329         pg_data_t *pgdat;
 330         unsigned long i;
 331         struct page *page;
 332         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 333
 334         num_physpages = max_pfn;        /* RAM is assumed contiguous */
 335         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 336
 337 #ifdef CONFIG_NEED_MULTIPLE_NODES
 338         for_each_online_node(nid) {
 339                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 340                         printk("freeing bootmem node %x\n", nid);
 341                         totalram_pages +=
 342                                 free_all_bootmem_node(NODE_DATA(nid));
 343                 }
 344         }
 345 #else
 346         max_mapnr = num_physpages;
 347         totalram_pages += free_all_bootmem();
 348 #endif
 349         for_each_pgdat(pgdat) {
 350                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 351                         page = pgdat_page_nr(pgdat, i);
 352                         if (PageReserved(page))
 353                                 reservedpages++;
 354                 }
 355         }
 356
 357         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 358         datasize = (unsigned long)&__init_begin - (unsigned long)&_sdata;
 359         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 360         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 361
 362 #ifdef CONFIG_HIGHMEM
 363         {
 364                 unsigned long pfn, highmem_mapnr;
 365
 366                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 367                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 368                         struct page *page = pfn_to_page(pfn);
 369
 370                         ClearPageReserved(page);
 371                         set_page_count(page, 1);
 372                         __free_page(page);
 373                         totalhigh_pages++;
 374                 }
 375                 totalram_pages += totalhigh_pages;
 376                 printk(KERN_INFO "High memory: %luk\n",
 377                        totalhigh_pages << (PAGE_SHIFT-10));
 378         }
 379 #endif /* CONFIG_HIGHMEM */
 380
 381         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 382                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 383                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 384                 num_physpages << (PAGE_SHIFT-10),
 385                 codesize >> 10,
 386                 reservedpages << (PAGE_SHIFT-10),
 387                 datasize >> 10,
 388                 bsssize >> 10,
 389                 initsize >> 10);
 390
 391         mem_init_done = 1;
 392
 393 #ifdef CONFIG_PPC64
 394         /* Initialize the vDSO */
 395         vdso_init();
 396 #endif
 397 }
 398
 399 /*
 400  * This is called when a page has been modified by the kernel.
 401  * It just marks the page as not i-cache clean.  We do the i-cache
 402  * flush later when the page is given to a user process, if necessary.
 403  */
 404 void flush_dcache_page(struct page *page)
 405 {
 406         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 407                 return;
 408         /* avoid an atomic op if possible */
 409         if (test_bit(PG_arch_1, &page->flags))
 410                 clear_bit(PG_arch_1, &page->flags);
 411 }
 412 EXPORT_SYMBOL(flush_dcache_page);
 413
 414 void flush_dcache_icache_page(struct page *page)
 415 {
 416 #ifdef CONFIG_BOOKE
 417         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 418         __flush_dcache_icache(start);
 419         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 420 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 421         /* On 8xx there is no need to kmap since highmem is not supported */
 422         __flush_dcache_icache(page_address(page));
 423 #else
 424         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 425 #endif
 426
 427 }
 428 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 429 {
 430         clear_page(page);
 431
 432         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 433                 return;
 434         /*
 435          * We shouldnt have to do this, but some versions of glibc
 436          * require it (ld.so assumes zero filled pages are icache clean)
 437          * - Anton
 438          */
 439
 440         /* avoid an atomic op if possible */
 441         if (test_bit(PG_arch_1, &pg->flags))
 442                 clear_bit(PG_arch_1, &pg->flags);
 443 }
 444 EXPORT_SYMBOL(clear_user_page);
 445
 446 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 447                     struct page *pg)
 448 {
 449         copy_page(vto, vfrom);
 450
 451         /*
 452          * We should be able to use the following optimisation, however
 453          * there are two problems.
 454          * Firstly a bug in some versions of binutils meant PLT sections
 455          * were not marked executable.
 456          * Secondly the first word in the GOT section is blrl, used
 457          * to establish the GOT address. Until recently the GOT was
 458          * not marked executable.
 459          * - Anton
 460          */
 461 #if 0
 462         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 463                 return;
 464 #endif
 465
 466         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 467                 return;
 468
 469         /* avoid an atomic op if possible */
 470         if (test_bit(PG_arch_1, &pg->flags))
 471                 clear_bit(PG_arch_1, &pg->flags);
 472 }
 473
 474 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 475                              unsigned long addr, int len)
 476 {
 477         unsigned long maddr;
 478
 479         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 480         flush_icache_range(maddr, maddr + len);
 481         kunmap(page);
 482 }
 483 EXPORT_SYMBOL(flush_icache_user_range);
 484
 485 /*
 486  * This is called at the end of handling a user page fault, when the
 487  * fault has been handled by updating a PTE in the linux page tables.
 488  * We use it to preload an HPTE into the hash table corresponding to
 489  * the updated linux PTE.
 490  *
 491  * This must always be called with the mm->page_table_lock held
 492  */
 493 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 494                       pte_t pte)
 495 {
 496         /* handle i-cache coherency */
 497         unsigned long pfn = pte_pfn(pte);
 498 #ifdef CONFIG_PPC32
 499         pmd_t *pmd;
 500 #else
 501         unsigned long vsid;
 502         void *pgdir;
 503         pte_t *ptep;
 504         int local = 0;
 505         cpumask_t tmp;
 506         unsigned long flags;
 507 #endif
 508
 509         /* handle i-cache coherency */
 510         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 511             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 512             pfn_valid(pfn)) {
 513                 struct page *page = pfn_to_page(pfn);
 514                 if (!PageReserved(page)
 515                     && !test_bit(PG_arch_1, &page->flags)) {
 516                         if (vma->vm_mm == current->active_mm) {
 517 #ifdef CONFIG_8xx
 518                         /* On 8xx, cache control instructions (particularly
 519                          * "dcbst" from flush_dcache_icache) fault as write
 520                          * operation if there is an unpopulated TLB entry
 521                          * for the address in question. To workaround that,
 522                          * we invalidate the TLB here, thus avoiding dcbst
 523                          * misbehaviour.
 524                          */
 525                                 _tlbie(address);
 526 #endif
 527                                 __flush_dcache_icache((void *) address);
 528                         } else
 529                                 flush_dcache_icache_page(page);
 530                         set_bit(PG_arch_1, &page->flags);
 531                 }
 532         }
 533
 534 #ifdef CONFIG_PPC_STD_MMU
 535         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 536         if (!pte_young(pte) || address >= TASK_SIZE)
 537                 return;
 538 #ifdef CONFIG_PPC32
 539         if (Hash == 0)
 540                 return;
 541         pmd = pmd_offset(pgd_offset(vma->vm_mm, address), address);
 542         if (!pmd_none(*pmd))
 543                 add_hash_page(vma->vm_mm->context, address, pmd_val(*pmd));
 544 #else
 545         pgdir = vma->vm_mm->pgd;
 546         if (pgdir == NULL)
 547                 return;
 548
 549         ptep = find_linux_pte(pgdir, address);
 550         if (!ptep)
 551                 return;
 552
 553         vsid = get_vsid(vma->vm_mm->context.id, address);
 554
 555         local_irq_save(flags);
 556         tmp = cpumask_of_cpu(smp_processor_id());
 557         if (cpus_equal(vma->vm_mm->cpu_vm_mask, tmp))
 558                 local = 1;
 559
 560         __hash_page(address, 0, vsid, ptep, 0x300, local);
 561         local_irq_restore(flags);
 562 #endif
 563 #endif
 564 }