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  *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
   9  *
  10  *  Derived from "arch/i386/mm/init.c"
  11  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  12  *
  13  *  This program is free software; you can redistribute it and/or
  14  *  modify it under the terms of the GNU General Public License
  15  *  as published by the Free Software Foundation; either version
  16  *  2 of the License, or (at your option) any later version.
  17  *
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/sched.h>
  22 #include <linux/kernel.h>
  23 #include <linux/errno.h>
  24 #include <linux/string.h>
  25 #include <linux/types.h>
  26 #include <linux/mm.h>
  27 #include <linux/stddef.h>
  28 #include <linux/init.h>
  29 #include <linux/bootmem.h>
  30 #include <linux/highmem.h>
  31 #include <linux/initrd.h>
  32 #include <linux/pagemap.h>
  33 #include <linux/suspend.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/lmb.h>
  46 #include <asm/sections.h>
  47 #include <asm/vdso.h>
  48
  49 #include "mmu_decl.h"
  50
  51 #ifndef CPU_FTR_COHERENT_ICACHE
  52 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  53 #define CPU_FTR_NOEXECUTE       0
  54 #endif
  55
  56 int init_bootmem_done;
  57 int mem_init_done;
  58 unsigned long memory_limit;
  59
  60 int page_is_ram(unsigned long pfn)
  61 {
  62         unsigned long paddr = (pfn << PAGE_SHIFT);
  63
  64 #ifndef CONFIG_PPC64    /* XXX for now */
  65         return paddr < __pa(high_memory);
  66 #else
  67         int i;
  68         for (i=0; i < lmb.memory.cnt; i++) {
  69                 unsigned long base;
  70
  71                 base = lmb.memory.region[i].base;
  72
  73                 if ((paddr >= base) &&
  74                         (paddr < (base + lmb.memory.region[i].size))) {
  75                         return 1;
  76                 }
  77         }
  78
  79         return 0;
  80 #endif
  81 }
  82
  83 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  84                               unsigned long size, pgprot_t vma_prot)
  85 {
  86         if (ppc_md.phys_mem_access_prot)
  87                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  88
  89         if (!page_is_ram(pfn))
  90                 vma_prot = __pgprot(pgprot_val(vma_prot)
  91                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
  92         return vma_prot;
  93 }
  94 EXPORT_SYMBOL(phys_mem_access_prot);
  95
  96 #ifdef CONFIG_MEMORY_HOTPLUG
  97
  98 void online_page(struct page *page)
  99 {
 100         ClearPageReserved(page);
 101         init_page_count(page);
 102         __free_page(page);
 103         totalram_pages++;
 104         num_physpages++;
 105 }
 106
 107 #ifdef CONFIG_NUMA
 108 int memory_add_physaddr_to_nid(u64 start)
 109 {
 110         return hot_add_scn_to_nid(start);
 111 }
 112 #endif
 113
 114 int __devinit arch_add_memory(int nid, u64 start, u64 size)
 115 {
 116         struct pglist_data *pgdata;
 117         struct zone *zone;
 118         unsigned long start_pfn = start >> PAGE_SHIFT;
 119         unsigned long nr_pages = size >> PAGE_SHIFT;
 120
 121         pgdata = NODE_DATA(nid);
 122
 123         start = (unsigned long)__va(start);
 124         create_section_mapping(start, start + size);
 125
 126         /* this should work for most non-highmem platforms */
 127         zone = pgdata->node_zones;
 128
 129         return __add_pages(zone, start_pfn, nr_pages);
 130 }
 131
 132 /*
 133  * First pass at this code will check to determine if the remove
 134  * request is within the RMO.  Do not allow removal within the RMO.
 135  */
 136 int __devinit remove_memory(u64 start, u64 size)
 137 {
 138         struct zone *zone;
 139         unsigned long start_pfn, end_pfn, nr_pages;
 140
 141         start_pfn = start >> PAGE_SHIFT;
 142         nr_pages = size >> PAGE_SHIFT;
 143         end_pfn = start_pfn + nr_pages;
 144
 145         printk("%s(): Attempting to remove memoy in range "
 146                         "%lx to %lx\n", __func__, start, start+size);
 147         /*
 148          * check for range within RMO
 149          */
 150         zone = page_zone(pfn_to_page(start_pfn));
 151
 152         printk("%s(): memory will be removed from "
 153                         "the %s zone\n", __func__, zone->name);
 154
 155         /*
 156          * not handling removing memory ranges that
 157          * overlap multiple zones yet
 158          */
 159         if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
 160                 goto overlap;
 161
 162         /* make sure it is NOT in RMO */
 163         if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
 164                 printk("%s(): range to be removed must NOT be in RMO!\n",
 165                         __func__);
 166                 goto in_rmo;
 167         }
 168
 169         return __remove_pages(zone, start_pfn, nr_pages);
 170
 171 overlap:
 172         printk("%s(): memory range to be removed overlaps "
 173                 "multiple zones!!!\n", __func__);
 174 in_rmo:
 175         return -1;
 176 }
 177 #endif /* CONFIG_MEMORY_HOTPLUG */
 178
 179 void show_mem(void)
 180 {
 181         unsigned long total = 0, reserved = 0;
 182         unsigned long shared = 0, cached = 0;
 183         unsigned long highmem = 0;
 184         struct page *page;
 185         pg_data_t *pgdat;
 186         unsigned long i;
 187
 188         printk("Mem-info:\n");
 189         show_free_areas();
 190         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 191         for_each_online_pgdat(pgdat) {
 192                 unsigned long flags;
 193                 pgdat_resize_lock(pgdat, &flags);
 194                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 195                         if (!pfn_valid(pgdat->node_start_pfn + i))
 196                                 continue;
 197                         page = pgdat_page_nr(pgdat, i);
 198                         total++;
 199                         if (PageHighMem(page))
 200                                 highmem++;
 201                         if (PageReserved(page))
 202                                 reserved++;
 203                         else if (PageSwapCache(page))
 204                                 cached++;
 205                         else if (page_count(page))
 206                                 shared += page_count(page) - 1;
 207                 }
 208                 pgdat_resize_unlock(pgdat, &flags);
 209         }
 210         printk("%ld pages of RAM\n", total);
 211 #ifdef CONFIG_HIGHMEM
 212         printk("%ld pages of HIGHMEM\n", highmem);
 213 #endif
 214         printk("%ld reserved pages\n", reserved);
 215         printk("%ld pages shared\n", shared);
 216         printk("%ld pages swap cached\n", cached);
 217 }
 218
 219 /*
 220  * Initialize the bootmem system and give it all the memory we
 221  * have available.  If we are using highmem, we only put the
 222  * lowmem into the bootmem system.
 223  */
 224 #ifndef CONFIG_NEED_MULTIPLE_NODES
 225 void __init do_init_bootmem(void)
 226 {
 227         unsigned long i;
 228         unsigned long start, bootmap_pages;
 229         unsigned long total_pages;
 230         int boot_mapsize;
 231
 232         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 233 #ifdef CONFIG_HIGHMEM
 234         total_pages = total_lowmem >> PAGE_SHIFT;
 235 #endif
 236
 237         /*
 238          * Find an area to use for the bootmem bitmap.  Calculate the size of
 239          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 240          * Add 1 additional page in case the address isn't page-aligned.
 241          */
 242         bootmap_pages = bootmem_bootmap_pages(total_pages);
 243
 244         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 245
 246         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 247
 248         /* Add active regions with valid PFNs */
 249         for (i = 0; i < lmb.memory.cnt; i++) {
 250                 unsigned long start_pfn, end_pfn;
 251                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 252                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 253                 add_active_range(0, start_pfn, end_pfn);
 254         }
 255
 256         /* Add all physical memory to the bootmem map, mark each area
 257          * present.
 258          */
 259 #ifdef CONFIG_HIGHMEM
 260         free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);
 261 #else
 262         free_bootmem_with_active_regions(0, max_pfn);
 263 #endif
 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         sparse_memory_present_with_active_regions(0);
 272
 273         init_bootmem_done = 1;
 274 }
 275
 276 /* mark pages that don't exist as nosave */
 277 static int __init mark_nonram_nosave(void)
 278 {
 279         unsigned long lmb_next_region_start_pfn,
 280                       lmb_region_max_pfn;
 281         int i;
 282
 283         for (i = 0; i < lmb.memory.cnt - 1; i++) {
 284                 lmb_region_max_pfn =
 285                         (lmb.memory.region[i].base >> PAGE_SHIFT) +
 286                         (lmb.memory.region[i].size >> PAGE_SHIFT);
 287                 lmb_next_region_start_pfn =
 288                         lmb.memory.region[i+1].base >> PAGE_SHIFT;
 289
 290                 if (lmb_region_max_pfn < lmb_next_region_start_pfn)
 291                         register_nosave_region(lmb_region_max_pfn,
 292                                                lmb_next_region_start_pfn);
 293         }
 294
 295         return 0;
 296 }
 297
 298 /*
 299  * paging_init() sets up the page tables - in fact we've already done this.
 300  */
 301 void __init paging_init(void)
 302 {
 303         unsigned long total_ram = lmb_phys_mem_size();
 304         unsigned long top_of_ram = lmb_end_of_DRAM();
 305         unsigned long max_zone_pfns[MAX_NR_ZONES];
 306
 307 #ifdef CONFIG_HIGHMEM
 308         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 309         pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 310                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 311         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 312         kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 313                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
 314                          KMAP_FIX_BEGIN);
 315         kmap_prot = PAGE_KERNEL;
 316 #endif /* CONFIG_HIGHMEM */
 317
 318         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 319                top_of_ram, total_ram);
 320         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 321                (top_of_ram - total_ram) >> 20);
 322         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 323 #ifdef CONFIG_HIGHMEM
 324         max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 325         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 326 #else
 327         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 328 #endif
 329         free_area_init_nodes(max_zone_pfns);
 330
 331         mark_nonram_nosave();
 332 }
 333 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 334
 335 void __init mem_init(void)
 336 {
 337 #ifdef CONFIG_NEED_MULTIPLE_NODES
 338         int nid;
 339 #endif
 340         pg_data_t *pgdat;
 341         unsigned long i;
 342         struct page *page;
 343         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 344
 345         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 346         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 347
 348 #ifdef CONFIG_NEED_MULTIPLE_NODES
 349         for_each_online_node(nid) {
 350                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 351                         printk("freeing bootmem node %d\n", nid);
 352                         totalram_pages +=
 353                                 free_all_bootmem_node(NODE_DATA(nid));
 354                 }
 355         }
 356 #else
 357         max_mapnr = max_pfn;
 358         totalram_pages += free_all_bootmem();
 359 #endif
 360         for_each_online_pgdat(pgdat) {
 361                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 362                         if (!pfn_valid(pgdat->node_start_pfn + i))
 363                                 continue;
 364                         page = pgdat_page_nr(pgdat, i);
 365                         if (PageReserved(page))
 366                                 reservedpages++;
 367                 }
 368         }
 369
 370         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 371         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 372         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 373         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 374
 375 #ifdef CONFIG_HIGHMEM
 376         {
 377                 unsigned long pfn, highmem_mapnr;
 378
 379                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 380                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 381                         struct page *page = pfn_to_page(pfn);
 382
 383                         ClearPageReserved(page);
 384                         init_page_count(page);
 385                         __free_page(page);
 386                         totalhigh_pages++;
 387                 }
 388                 totalram_pages += totalhigh_pages;
 389                 printk(KERN_DEBUG "High memory: %luk\n",
 390                        totalhigh_pages << (PAGE_SHIFT-10));
 391         }
 392 #endif /* CONFIG_HIGHMEM */
 393
 394         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 395                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 396                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 397                 num_physpages << (PAGE_SHIFT-10),
 398                 codesize >> 10,
 399                 reservedpages << (PAGE_SHIFT-10),
 400                 datasize >> 10,
 401                 bsssize >> 10,
 402                 initsize >> 10);
 403
 404         mem_init_done = 1;
 405 }
 406
 407 /*
 408  * This is called when a page has been modified by the kernel.
 409  * It just marks the page as not i-cache clean.  We do the i-cache
 410  * flush later when the page is given to a user process, if necessary.
 411  */
 412 void flush_dcache_page(struct page *page)
 413 {
 414         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 415                 return;
 416         /* avoid an atomic op if possible */
 417         if (test_bit(PG_arch_1, &page->flags))
 418                 clear_bit(PG_arch_1, &page->flags);
 419 }
 420 EXPORT_SYMBOL(flush_dcache_page);
 421
 422 void flush_dcache_icache_page(struct page *page)
 423 {
 424 #ifdef CONFIG_BOOKE
 425         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 426         __flush_dcache_icache(start);
 427         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 428 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 429         /* On 8xx there is no need to kmap since highmem is not supported */
 430         __flush_dcache_icache(page_address(page));
 431 #else
 432         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 433 #endif
 434
 435 }
 436 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 437 {
 438         clear_page(page);
 439
 440         /*
 441          * We shouldnt have to do this, but some versions of glibc
 442          * require it (ld.so assumes zero filled pages are icache clean)
 443          * - Anton
 444          */
 445         flush_dcache_page(pg);
 446 }
 447 EXPORT_SYMBOL(clear_user_page);
 448
 449 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 450                     struct page *pg)
 451 {
 452         copy_page(vto, vfrom);
 453
 454         /*
 455          * We should be able to use the following optimisation, however
 456          * there are two problems.
 457          * Firstly a bug in some versions of binutils meant PLT sections
 458          * were not marked executable.
 459          * Secondly the first word in the GOT section is blrl, used
 460          * to establish the GOT address. Until recently the GOT was
 461          * not marked executable.
 462          * - Anton
 463          */
 464 #if 0
 465         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 466                 return;
 467 #endif
 468
 469         flush_dcache_page(pg);
 470 }
 471
 472 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 473                              unsigned long addr, int len)
 474 {
 475         unsigned long maddr;
 476
 477         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 478         flush_icache_range(maddr, maddr + len);
 479         kunmap(page);
 480 }
 481 EXPORT_SYMBOL(flush_icache_user_range);
 482
 483 /*
 484  * This is called at the end of handling a user page fault, when the
 485  * fault has been handled by updating a PTE in the linux page tables.
 486  * We use it to preload an HPTE into the hash table corresponding to
 487  * the updated linux PTE.
 488  *
 489  * This must always be called with the pte lock held.
 490  */
 491 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 492                       pte_t pte)
 493 {
 494 #ifdef CONFIG_PPC_STD_MMU
 495         unsigned long access = 0, trap;
 496 #endif
 497         unsigned long pfn = pte_pfn(pte);
 498
 499         /* handle i-cache coherency */
 500         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 501             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 502             pfn_valid(pfn)) {
 503                 struct page *page = pfn_to_page(pfn);
 504 #ifdef CONFIG_8xx
 505                 /* On 8xx, cache control instructions (particularly
 506                  * "dcbst" from flush_dcache_icache) fault as write
 507                  * operation if there is an unpopulated TLB entry
 508                  * for the address in question. To workaround that,
 509                  * we invalidate the TLB here, thus avoiding dcbst
 510                  * misbehaviour.
 511                  */
 512                 _tlbie(address);
 513 #endif
 514                 if (!PageReserved(page)
 515                     && !test_bit(PG_arch_1, &page->flags)) {
 516                         if (vma->vm_mm == current->active_mm) {
 517                                 __flush_dcache_icache((void *) address);
 518                         } else
 519                                 flush_dcache_icache_page(page);
 520                         set_bit(PG_arch_1, &page->flags);
 521                 }
 522         }
 523
 524 #ifdef CONFIG_PPC_STD_MMU
 525         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 526         if (!pte_young(pte) || address >= TASK_SIZE)
 527                 return;
 528
 529         /* We try to figure out if we are coming from an instruction
 530          * access fault and pass that down to __hash_page so we avoid
 531          * double-faulting on execution of fresh text. We have to test
 532          * for regs NULL since init will get here first thing at boot
 533          *
 534          * We also avoid filling the hash if not coming from a fault
 535          */
 536         if (current->thread.regs == NULL)
 537                 return;
 538         trap = TRAP(current->thread.regs);
 539         if (trap == 0x400)
 540                 access |= _PAGE_EXEC;
 541         else if (trap != 0x300)
 542                 return;
 543         hash_preload(vma->vm_mm, address, access, trap);
 544 #endif /* CONFIG_PPC_STD_MMU */
 545 }