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