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 #include <linux/suspend.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 int page_is_ram(unsigned long pfn)
  63 {
  64         unsigned long paddr = (pfn << PAGE_SHIFT);
  65
  66 #ifndef CONFIG_PPC64    /* XXX for now */
  67         return paddr < __pa(high_memory);
  68 #else
  69         int i;
  70         for (i=0; i < lmb.memory.cnt; i++) {
  71                 unsigned long base;
  72
  73                 base = lmb.memory.region[i].base;
  74
  75                 if ((paddr >= base) &&
  76                         (paddr < (base + lmb.memory.region[i].size))) {
  77                         return 1;
  78                 }
  79         }
  80
  81         return 0;
  82 #endif
  83 }
  84
  85 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  86                               unsigned long size, pgprot_t vma_prot)
  87 {
  88         if (ppc_md.phys_mem_access_prot)
  89                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  90
  91         if (!page_is_ram(pfn))
  92                 vma_prot = __pgprot(pgprot_val(vma_prot)
  93                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
  94         return vma_prot;
  95 }
  96 EXPORT_SYMBOL(phys_mem_access_prot);
  97
  98 #ifdef CONFIG_MEMORY_HOTPLUG
  99
 100 void online_page(struct page *page)
 101 {
 102         ClearPageReserved(page);
 103         init_page_count(page);
 104         __free_page(page);
 105         totalram_pages++;
 106         num_physpages++;
 107 }
 108
 109 #ifdef CONFIG_NUMA
 110 int memory_add_physaddr_to_nid(u64 start)
 111 {
 112         return hot_add_scn_to_nid(start);
 113 }
 114 #endif
 115
 116 int __devinit arch_add_memory(int nid, u64 start, u64 size)
 117 {
 118         struct pglist_data *pgdata;
 119         struct zone *zone;
 120         unsigned long start_pfn = start >> PAGE_SHIFT;
 121         unsigned long nr_pages = size >> PAGE_SHIFT;
 122
 123         pgdata = NODE_DATA(nid);
 124
 125         start = (unsigned long)__va(start);
 126         create_section_mapping(start, start + size);
 127
 128         /* this should work for most non-highmem platforms */
 129         zone = pgdata->node_zones;
 130
 131         return __add_pages(zone, start_pfn, nr_pages);
 132
 133         return 0;
 134 }
 135
 136 /*
 137  * First pass at this code will check to determine if the remove
 138  * request is within the RMO.  Do not allow removal within the RMO.
 139  */
 140 int __devinit remove_memory(u64 start, u64 size)
 141 {
 142         struct zone *zone;
 143         unsigned long start_pfn, end_pfn, nr_pages;
 144
 145         start_pfn = start >> PAGE_SHIFT;
 146         nr_pages = size >> PAGE_SHIFT;
 147         end_pfn = start_pfn + nr_pages;
 148
 149         printk("%s(): Attempting to remove memoy in range "
 150                         "%lx to %lx\n", __func__, start, start+size);
 151         /*
 152          * check for range within RMO
 153          */
 154         zone = page_zone(pfn_to_page(start_pfn));
 155
 156         printk("%s(): memory will be removed from "
 157                         "the %s zone\n", __func__, zone->name);
 158
 159         /*
 160          * not handling removing memory ranges that
 161          * overlap multiple zones yet
 162          */
 163         if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
 164                 goto overlap;
 165
 166         /* make sure it is NOT in RMO */
 167         if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
 168                 printk("%s(): range to be removed must NOT be in RMO!\n",
 169                         __func__);
 170                 goto in_rmo;
 171         }
 172
 173         return __remove_pages(zone, start_pfn, nr_pages);
 174
 175 overlap:
 176         printk("%s(): memory range to be removed overlaps "
 177                 "multiple zones!!!\n", __func__);
 178 in_rmo:
 179         return -1;
 180 }
 181 #endif /* CONFIG_MEMORY_HOTPLUG */
 182
 183 void show_mem(void)
 184 {
 185         unsigned long total = 0, reserved = 0;
 186         unsigned long shared = 0, cached = 0;
 187         unsigned long highmem = 0;
 188         struct page *page;
 189         pg_data_t *pgdat;
 190         unsigned long i;
 191
 192         printk("Mem-info:\n");
 193         show_free_areas();
 194         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 195         for_each_online_pgdat(pgdat) {
 196                 unsigned long flags;
 197                 pgdat_resize_lock(pgdat, &flags);
 198                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 199                         if (!pfn_valid(pgdat->node_start_pfn + i))
 200                                 continue;
 201                         page = pgdat_page_nr(pgdat, i);
 202                         total++;
 203                         if (PageHighMem(page))
 204                                 highmem++;
 205                         if (PageReserved(page))
 206                                 reserved++;
 207                         else if (PageSwapCache(page))
 208                                 cached++;
 209                         else if (page_count(page))
 210                                 shared += page_count(page) - 1;
 211                 }
 212                 pgdat_resize_unlock(pgdat, &flags);
 213         }
 214         printk("%ld pages of RAM\n", total);
 215 #ifdef CONFIG_HIGHMEM
 216         printk("%ld pages of HIGHMEM\n", highmem);
 217 #endif
 218         printk("%ld reserved pages\n", reserved);
 219         printk("%ld pages shared\n", shared);
 220         printk("%ld pages swap cached\n", cached);
 221 }
 222
 223 /*
 224  * Initialize the bootmem system and give it all the memory we
 225  * have available.  If we are using highmem, we only put the
 226  * lowmem into the bootmem system.
 227  */
 228 #ifndef CONFIG_NEED_MULTIPLE_NODES
 229 void __init do_init_bootmem(void)
 230 {
 231         unsigned long i;
 232         unsigned long start, bootmap_pages;
 233         unsigned long total_pages;
 234         int boot_mapsize;
 235
 236         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 237 #ifdef CONFIG_HIGHMEM
 238         total_pages = total_lowmem >> PAGE_SHIFT;
 239 #endif
 240
 241         /*
 242          * Find an area to use for the bootmem bitmap.  Calculate the size of
 243          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 244          * Add 1 additional page in case the address isn't page-aligned.
 245          */
 246         bootmap_pages = bootmem_bootmap_pages(total_pages);
 247
 248         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 249
 250         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 251
 252         /* Add active regions with valid PFNs */
 253         for (i = 0; i < lmb.memory.cnt; i++) {
 254                 unsigned long start_pfn, end_pfn;
 255                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 256                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 257                 add_active_range(0, start_pfn, end_pfn);
 258         }
 259
 260         /* Add all physical memory to the bootmem map, mark each area
 261          * present.
 262          */
 263 #ifdef CONFIG_HIGHMEM
 264         free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);
 265 #else
 266         free_bootmem_with_active_regions(0, max_pfn);
 267 #endif
 268
 269         /* reserve the sections we're already using */
 270         for (i = 0; i < lmb.reserved.cnt; i++)
 271                 reserve_bootmem(lmb.reserved.region[i].base,
 272                                 lmb_size_bytes(&lmb.reserved, i));
 273
 274         /* XXX need to clip this if using highmem? */
 275         sparse_memory_present_with_active_regions(0);
 276
 277         init_bootmem_done = 1;
 278 }
 279
 280 /* mark pages that don't exist as nosave */
 281 static int __init mark_nonram_nosave(void)
 282 {
 283         unsigned long lmb_next_region_start_pfn,
 284                       lmb_region_max_pfn;
 285         int i;
 286
 287         for (i = 0; i < lmb.memory.cnt - 1; i++) {
 288                 lmb_region_max_pfn =
 289                         (lmb.memory.region[i].base >> PAGE_SHIFT) +
 290                         (lmb.memory.region[i].size >> PAGE_SHIFT);
 291                 lmb_next_region_start_pfn =
 292                         lmb.memory.region[i+1].base >> PAGE_SHIFT;
 293
 294                 if (lmb_region_max_pfn < lmb_next_region_start_pfn)
 295                         register_nosave_region(lmb_region_max_pfn,
 296                                                lmb_next_region_start_pfn);
 297         }
 298
 299         return 0;
 300 }
 301
 302 /*
 303  * paging_init() sets up the page tables - in fact we've already done this.
 304  */
 305 void __init paging_init(void)
 306 {
 307         unsigned long total_ram = lmb_phys_mem_size();
 308         unsigned long top_of_ram = lmb_end_of_DRAM();
 309         unsigned long max_zone_pfns[MAX_NR_ZONES];
 310
 311 #ifdef CONFIG_HIGHMEM
 312         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 313         pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 314                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 315         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 316         kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 317                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
 318                          KMAP_FIX_BEGIN);
 319         kmap_prot = PAGE_KERNEL;
 320 #endif /* CONFIG_HIGHMEM */
 321
 322         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 323                top_of_ram, total_ram);
 324         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 325                (top_of_ram - total_ram) >> 20);
 326         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 327 #ifdef CONFIG_HIGHMEM
 328         max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 329         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 330 #else
 331         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 332 #endif
 333         free_area_init_nodes(max_zone_pfns);
 334
 335         mark_nonram_nosave();
 336 }
 337 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 338
 339 void __init mem_init(void)
 340 {
 341 #ifdef CONFIG_NEED_MULTIPLE_NODES
 342         int nid;
 343 #endif
 344         pg_data_t *pgdat;
 345         unsigned long i;
 346         struct page *page;
 347         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 348
 349         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 350         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 351
 352 #ifdef CONFIG_NEED_MULTIPLE_NODES
 353         for_each_online_node(nid) {
 354                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 355                         printk("freeing bootmem node %d\n", nid);
 356                         totalram_pages +=
 357                                 free_all_bootmem_node(NODE_DATA(nid));
 358                 }
 359         }
 360 #else
 361         max_mapnr = max_pfn;
 362         totalram_pages += free_all_bootmem();
 363 #endif
 364         for_each_online_pgdat(pgdat) {
 365                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 366                         if (!pfn_valid(pgdat->node_start_pfn + i))
 367                                 continue;
 368                         page = pgdat_page_nr(pgdat, i);
 369                         if (PageReserved(page))
 370                                 reservedpages++;
 371                 }
 372         }
 373
 374         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 375         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 376         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 377         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 378
 379 #ifdef CONFIG_HIGHMEM
 380         {
 381                 unsigned long pfn, highmem_mapnr;
 382
 383                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 384                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 385                         struct page *page = pfn_to_page(pfn);
 386
 387                         ClearPageReserved(page);
 388                         init_page_count(page);
 389                         __free_page(page);
 390                         totalhigh_pages++;
 391                 }
 392                 totalram_pages += totalhigh_pages;
 393                 printk(KERN_DEBUG "High memory: %luk\n",
 394                        totalhigh_pages << (PAGE_SHIFT-10));
 395         }
 396 #endif /* CONFIG_HIGHMEM */
 397
 398         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 399                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 400                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 401                 num_physpages << (PAGE_SHIFT-10),
 402                 codesize >> 10,
 403                 reservedpages << (PAGE_SHIFT-10),
 404                 datasize >> 10,
 405                 bsssize >> 10,
 406                 initsize >> 10);
 407
 408         mem_init_done = 1;
 409 }
 410
 411 /*
 412  * This is called when a page has been modified by the kernel.
 413  * It just marks the page as not i-cache clean.  We do the i-cache
 414  * flush later when the page is given to a user process, if necessary.
 415  */
 416 void flush_dcache_page(struct page *page)
 417 {
 418         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 419                 return;
 420         /* avoid an atomic op if possible */
 421         if (test_bit(PG_arch_1, &page->flags))
 422                 clear_bit(PG_arch_1, &page->flags);
 423 }
 424 EXPORT_SYMBOL(flush_dcache_page);
 425
 426 void flush_dcache_icache_page(struct page *page)
 427 {
 428 #ifdef CONFIG_BOOKE
 429         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 430         __flush_dcache_icache(start);
 431         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 432 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 433         /* On 8xx there is no need to kmap since highmem is not supported */
 434         __flush_dcache_icache(page_address(page));
 435 #else
 436         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 437 #endif
 438
 439 }
 440 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 441 {
 442         clear_page(page);
 443
 444         /*
 445          * We shouldnt have to do this, but some versions of glibc
 446          * require it (ld.so assumes zero filled pages are icache clean)
 447          * - Anton
 448          */
 449         flush_dcache_page(pg);
 450 }
 451 EXPORT_SYMBOL(clear_user_page);
 452
 453 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 454                     struct page *pg)
 455 {
 456         copy_page(vto, vfrom);
 457
 458         /*
 459          * We should be able to use the following optimisation, however
 460          * there are two problems.
 461          * Firstly a bug in some versions of binutils meant PLT sections
 462          * were not marked executable.
 463          * Secondly the first word in the GOT section is blrl, used
 464          * to establish the GOT address. Until recently the GOT was
 465          * not marked executable.
 466          * - Anton
 467          */
 468 #if 0
 469         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 470                 return;
 471 #endif
 472
 473         flush_dcache_page(pg);
 474 }
 475
 476 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 477                              unsigned long addr, int len)
 478 {
 479         unsigned long maddr;
 480
 481         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 482         flush_icache_range(maddr, maddr + len);
 483         kunmap(page);
 484 }
 485 EXPORT_SYMBOL(flush_icache_user_range);
 486
 487 /*
 488  * This is called at the end of handling a user page fault, when the
 489  * fault has been handled by updating a PTE in the linux page tables.
 490  * We use it to preload an HPTE into the hash table corresponding to
 491  * the updated linux PTE.
 492  *
 493  * This must always be called with the pte lock held.
 494  */
 495 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 496                       pte_t pte)
 497 {
 498 #ifdef CONFIG_PPC_STD_MMU
 499         unsigned long access = 0, trap;
 500 #endif
 501         unsigned long pfn = pte_pfn(pte);
 502
 503         /* handle i-cache coherency */
 504         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 505             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 506             pfn_valid(pfn)) {
 507                 struct page *page = pfn_to_page(pfn);
 508 #ifdef CONFIG_8xx
 509                 /* On 8xx, cache control instructions (particularly
 510                  * "dcbst" from flush_dcache_icache) fault as write
 511                  * operation if there is an unpopulated TLB entry
 512                  * for the address in question. To workaround that,
 513                  * we invalidate the TLB here, thus avoiding dcbst
 514                  * misbehaviour.
 515                  */
 516                 _tlbie(address);
 517 #endif
 518                 if (!PageReserved(page)
 519                     && !test_bit(PG_arch_1, &page->flags)) {
 520                         if (vma->vm_mm == current->active_mm) {
 521                                 __flush_dcache_icache((void *) address);
 522                         } else
 523                                 flush_dcache_icache_page(page);
 524                         set_bit(PG_arch_1, &page->flags);
 525                 }
 526         }
 527
 528 #ifdef CONFIG_PPC_STD_MMU
 529         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 530         if (!pte_young(pte) || address >= TASK_SIZE)
 531                 return;
 532
 533         /* We try to figure out if we are coming from an instruction
 534          * access fault and pass that down to __hash_page so we avoid
 535          * double-faulting on execution of fresh text. We have to test
 536          * for regs NULL since init will get here first thing at boot
 537          *
 538          * We also avoid filling the hash if not coming from a fault
 539          */
 540         if (current->thread.regs == NULL)
 541                 return;
 542         trap = TRAP(current->thread.regs);
 543         if (trap == 0x400)
 544                 access |= _PAGE_EXEC;
 545         else if (trap != 0x300)
 546                 return;
 547         hash_preload(vma->vm_mm, address, access, trap);
 548 #endif /* CONFIG_PPC_STD_MMU */
 549 }