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/module.h>
  22 #include <linux/sched.h>
  23 #include <linux/kernel.h>
  24 #include <linux/errno.h>
  25 #include <linux/string.h>
  26 #include <linux/types.h>
  27 #include <linux/mm.h>
  28 #include <linux/stddef.h>
  29 #include <linux/init.h>
  30 #include <linux/bootmem.h>
  31 #include <linux/highmem.h>
  32 #include <linux/initrd.h>
  33 #include <linux/pagemap.h>
  34
  35 #include <asm/pgalloc.h>
  36 #include <asm/prom.h>
  37 #include <asm/io.h>
  38 #include <asm/mmu_context.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/mmu.h>
  41 #include <asm/smp.h>
  42 #include <asm/machdep.h>
  43 #include <asm/btext.h>
  44 #include <asm/tlb.h>
  45 #include <asm/prom.h>
  46 #include <asm/lmb.h>
  47 #include <asm/sections.h>
  48 #include <asm/vdso.h>
  49
  50 #include "mmu_decl.h"
  51
  52 #ifndef CPU_FTR_COHERENT_ICACHE
  53 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  54 #define CPU_FTR_NOEXECUTE       0
  55 #endif
  56
  57 int init_bootmem_done;
  58 int mem_init_done;
  59 unsigned long memory_limit;
  60
  61 int page_is_ram(unsigned long pfn)
  62 {
  63         unsigned long paddr = (pfn << PAGE_SHIFT);
  64
  65 #ifndef CONFIG_PPC64    /* XXX for now */
  66         return paddr < __pa(high_memory);
  67 #else
  68         int i;
  69         for (i=0; i < lmb.memory.cnt; i++) {
  70                 unsigned long base;
  71
  72                 base = lmb.memory.region[i].base;
  73
  74                 if ((paddr >= base) &&
  75                         (paddr < (base + lmb.memory.region[i].size))) {
  76                         return 1;
  77                 }
  78         }
  79
  80         return 0;
  81 #endif
  82 }
  83
  84 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  85                               unsigned long size, pgprot_t vma_prot)
  86 {
  87         if (ppc_md.phys_mem_access_prot)
  88                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  89
  90         if (!page_is_ram(pfn))
  91                 vma_prot = __pgprot(pgprot_val(vma_prot)
  92                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
  93         return vma_prot;
  94 }
  95 EXPORT_SYMBOL(phys_mem_access_prot);
  96
  97 #ifdef CONFIG_MEMORY_HOTPLUG
  98
  99 void online_page(struct page *page)
 100 {
 101         ClearPageReserved(page);
 102         init_page_count(page);
 103         __free_page(page);
 104         totalram_pages++;
 105         num_physpages++;
 106 }
 107
 108 #ifdef CONFIG_NUMA
 109 int memory_add_physaddr_to_nid(u64 start)
 110 {
 111         return hot_add_scn_to_nid(start);
 112 }
 113 #endif
 114
 115 int __devinit arch_add_memory(int nid, u64 start, u64 size)
 116 {
 117         struct pglist_data *pgdata;
 118         struct zone *zone;
 119         unsigned long start_pfn = start >> PAGE_SHIFT;
 120         unsigned long nr_pages = size >> PAGE_SHIFT;
 121
 122         pgdata = NODE_DATA(nid);
 123
 124         start = (unsigned long)__va(start);
 125         create_section_mapping(start, start + size);
 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_online_pgdat(pgdat) {
 195                 unsigned long flags;
 196                 pgdat_resize_lock(pgdat, &flags);
 197                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 198                         if (!pfn_valid(pgdat->node_start_pfn + i))
 199                                 continue;
 200                         page = pgdat_page_nr(pgdat, i);
 201                         total++;
 202                         if (PageHighMem(page))
 203                                 highmem++;
 204                         if (PageReserved(page))
 205                                 reserved++;
 206                         else if (PageSwapCache(page))
 207                                 cached++;
 208                         else if (page_count(page))
 209                                 shared += page_count(page) - 1;
 210                 }
 211                 pgdat_resize_unlock(pgdat, &flags);
 212         }
 213         printk("%ld pages of RAM\n", total);
 214 #ifdef CONFIG_HIGHMEM
 215         printk("%ld pages of HIGHMEM\n", highmem);
 216 #endif
 217         printk("%ld reserved pages\n", reserved);
 218         printk("%ld pages shared\n", shared);
 219         printk("%ld pages swap cached\n", cached);
 220 }
 221
 222 /*
 223  * Initialize the bootmem system and give it all the memory we
 224  * have available.  If we are using highmem, we only put the
 225  * lowmem into the bootmem system.
 226  */
 227 #ifndef CONFIG_NEED_MULTIPLE_NODES
 228 void __init do_init_bootmem(void)
 229 {
 230         unsigned long i;
 231         unsigned long start, bootmap_pages;
 232         unsigned long total_pages;
 233         int boot_mapsize;
 234
 235         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 236 #ifdef CONFIG_HIGHMEM
 237         total_pages = total_lowmem >> PAGE_SHIFT;
 238 #endif
 239
 240         /*
 241          * Find an area to use for the bootmem bitmap.  Calculate the size of
 242          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 243          * Add 1 additional page in case the address isn't page-aligned.
 244          */
 245         bootmap_pages = bootmem_bootmap_pages(total_pages);
 246
 247         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 248
 249         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 250
 251         /* Add active regions with valid PFNs */
 252         for (i = 0; i < lmb.memory.cnt; i++) {
 253                 unsigned long start_pfn, end_pfn;
 254                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 255                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 256                 add_active_range(0, start_pfn, end_pfn);
 257         }
 258
 259         /* Add all physical memory to the bootmem map, mark each area
 260          * present.
 261          */
 262 #ifdef CONFIG_HIGHMEM
 263         free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);
 264 #else
 265         free_bootmem_with_active_regions(0, max_pfn);
 266 #endif
 267
 268         /* reserve the sections we're already using */
 269         for (i = 0; i < lmb.reserved.cnt; i++)
 270                 reserve_bootmem(lmb.reserved.region[i].base,
 271                                 lmb_size_bytes(&lmb.reserved, i));
 272
 273         /* XXX need to clip this if using highmem? */
 274         sparse_memory_present_with_active_regions(0);
 275
 276         init_bootmem_done = 1;
 277 }
 278
 279 /*
 280  * paging_init() sets up the page tables - in fact we've already done this.
 281  */
 282 void __init paging_init(void)
 283 {
 284         unsigned long total_ram = lmb_phys_mem_size();
 285         unsigned long top_of_ram = lmb_end_of_DRAM();
 286         unsigned long max_zone_pfns[MAX_NR_ZONES];
 287
 288 #ifdef CONFIG_HIGHMEM
 289         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 290         pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
 291                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 292         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 293         kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
 294                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
 295         kmap_prot = PAGE_KERNEL;
 296 #endif /* CONFIG_HIGHMEM */
 297
 298         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 299                top_of_ram, total_ram);
 300         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 301                (top_of_ram - total_ram) >> 20);
 302         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 303 #ifdef CONFIG_HIGHMEM
 304         max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 305         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 306 #else
 307         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 308 #endif
 309         free_area_init_nodes(max_zone_pfns);
 310 }
 311 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 312
 313 void __init mem_init(void)
 314 {
 315 #ifdef CONFIG_NEED_MULTIPLE_NODES
 316         int nid;
 317 #endif
 318         pg_data_t *pgdat;
 319         unsigned long i;
 320         struct page *page;
 321         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 322
 323         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 324         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 325
 326 #ifdef CONFIG_NEED_MULTIPLE_NODES
 327         for_each_online_node(nid) {
 328                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 329                         printk("freeing bootmem node %d\n", nid);
 330                         totalram_pages +=
 331                                 free_all_bootmem_node(NODE_DATA(nid));
 332                 }
 333         }
 334 #else
 335         max_mapnr = max_pfn;
 336         totalram_pages += free_all_bootmem();
 337 #endif
 338         for_each_online_pgdat(pgdat) {
 339                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 340                         if (!pfn_valid(pgdat->node_start_pfn + i))
 341                                 continue;
 342                         page = pgdat_page_nr(pgdat, i);
 343                         if (PageReserved(page))
 344                                 reservedpages++;
 345                 }
 346         }
 347
 348         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 349         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 350         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 351         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 352
 353 #ifdef CONFIG_HIGHMEM
 354         {
 355                 unsigned long pfn, highmem_mapnr;
 356
 357                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 358                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 359                         struct page *page = pfn_to_page(pfn);
 360
 361                         ClearPageReserved(page);
 362                         init_page_count(page);
 363                         __free_page(page);
 364                         totalhigh_pages++;
 365                 }
 366                 totalram_pages += totalhigh_pages;
 367                 printk(KERN_DEBUG "High memory: %luk\n",
 368                        totalhigh_pages << (PAGE_SHIFT-10));
 369         }
 370 #endif /* CONFIG_HIGHMEM */
 371
 372         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 373                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 374                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 375                 num_physpages << (PAGE_SHIFT-10),
 376                 codesize >> 10,
 377                 reservedpages << (PAGE_SHIFT-10),
 378                 datasize >> 10,
 379                 bsssize >> 10,
 380                 initsize >> 10);
 381
 382         mem_init_done = 1;
 383 }
 384
 385 /*
 386  * This is called when a page has been modified by the kernel.
 387  * It just marks the page as not i-cache clean.  We do the i-cache
 388  * flush later when the page is given to a user process, if necessary.
 389  */
 390 void flush_dcache_page(struct page *page)
 391 {
 392         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 393                 return;
 394         /* avoid an atomic op if possible */
 395         if (test_bit(PG_arch_1, &page->flags))
 396                 clear_bit(PG_arch_1, &page->flags);
 397 }
 398 EXPORT_SYMBOL(flush_dcache_page);
 399
 400 void flush_dcache_icache_page(struct page *page)
 401 {
 402 #ifdef CONFIG_BOOKE
 403         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 404         __flush_dcache_icache(start);
 405         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 406 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 407         /* On 8xx there is no need to kmap since highmem is not supported */
 408         __flush_dcache_icache(page_address(page));
 409 #else
 410         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 411 #endif
 412
 413 }
 414 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 415 {
 416         clear_page(page);
 417
 418         /*
 419          * We shouldnt have to do this, but some versions of glibc
 420          * require it (ld.so assumes zero filled pages are icache clean)
 421          * - Anton
 422          */
 423         flush_dcache_page(pg);
 424 }
 425 EXPORT_SYMBOL(clear_user_page);
 426
 427 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 428                     struct page *pg)
 429 {
 430         copy_page(vto, vfrom);
 431
 432         /*
 433          * We should be able to use the following optimisation, however
 434          * there are two problems.
 435          * Firstly a bug in some versions of binutils meant PLT sections
 436          * were not marked executable.
 437          * Secondly the first word in the GOT section is blrl, used
 438          * to establish the GOT address. Until recently the GOT was
 439          * not marked executable.
 440          * - Anton
 441          */
 442 #if 0
 443         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 444                 return;
 445 #endif
 446
 447         flush_dcache_page(pg);
 448 }
 449
 450 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 451                              unsigned long addr, int len)
 452 {
 453         unsigned long maddr;
 454
 455         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 456         flush_icache_range(maddr, maddr + len);
 457         kunmap(page);
 458 }
 459 EXPORT_SYMBOL(flush_icache_user_range);
 460
 461 /*
 462  * This is called at the end of handling a user page fault, when the
 463  * fault has been handled by updating a PTE in the linux page tables.
 464  * We use it to preload an HPTE into the hash table corresponding to
 465  * the updated linux PTE.
 466  *
 467  * This must always be called with the pte lock held.
 468  */
 469 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 470                       pte_t pte)
 471 {
 472 #ifdef CONFIG_PPC_STD_MMU
 473         unsigned long access = 0, trap;
 474 #endif
 475         unsigned long pfn = pte_pfn(pte);
 476
 477         /* handle i-cache coherency */
 478         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 479             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 480             pfn_valid(pfn)) {
 481                 struct page *page = pfn_to_page(pfn);
 482 #ifdef CONFIG_8xx
 483                 /* On 8xx, cache control instructions (particularly
 484                  * "dcbst" from flush_dcache_icache) fault as write
 485                  * operation if there is an unpopulated TLB entry
 486                  * for the address in question. To workaround that,
 487                  * we invalidate the TLB here, thus avoiding dcbst
 488                  * misbehaviour.
 489                  */
 490                 _tlbie(address);
 491 #endif
 492                 if (!PageReserved(page)
 493                     && !test_bit(PG_arch_1, &page->flags)) {
 494                         if (vma->vm_mm == current->active_mm) {
 495                                 __flush_dcache_icache((void *) address);
 496                         } else
 497                                 flush_dcache_icache_page(page);
 498                         set_bit(PG_arch_1, &page->flags);
 499                 }
 500         }
 501
 502 #ifdef CONFIG_PPC_STD_MMU
 503         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 504         if (!pte_young(pte) || address >= TASK_SIZE)
 505                 return;
 506
 507         /* We try to figure out if we are coming from an instruction
 508          * access fault and pass that down to __hash_page so we avoid
 509          * double-faulting on execution of fresh text. We have to test
 510          * for regs NULL since init will get here first thing at boot
 511          *
 512          * We also avoid filling the hash if not coming from a fault
 513          */
 514         if (current->thread.regs == NULL)
 515                 return;
 516         trap = TRAP(current->thread.regs);
 517         if (trap == 0x400)
 518                 access |= _PAGE_EXEC;
 519         else if (trap != 0x300)
 520                 return;
 521         hash_preload(vma->vm_mm, address, access, trap);
 522 #endif /* CONFIG_PPC_STD_MMU */
 523 }