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 #include <asm/rtas.h>
  50 #include <asm/vdso.h>
  51
  52 #include "mmu_decl.h"
  53
  54 #ifndef CPU_FTR_COHERENT_ICACHE
  55 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  56 #define CPU_FTR_NOEXECUTE       0
  57 #endif
  58
  59 int init_bootmem_done;
  60 int mem_init_done;
  61 unsigned long memory_limit;
  62
  63 extern void hash_preload(struct mm_struct *mm, unsigned long ea,
  64                          unsigned long access, unsigned long trap);
  65
  66 /*
  67  * This is called by /dev/mem to know if a given address has to
  68  * be mapped non-cacheable or not
  69  */
  70 int page_is_ram(unsigned long pfn)
  71 {
  72         unsigned long paddr = (pfn << PAGE_SHIFT);
  73
  74 #ifndef CONFIG_PPC64    /* XXX for now */
  75         return paddr < __pa(high_memory);
  76 #else
  77         int i;
  78         for (i=0; i < lmb.memory.cnt; i++) {
  79                 unsigned long base;
  80
  81                 base = lmb.memory.region[i].base;
  82
  83                 if ((paddr >= base) &&
  84                         (paddr < (base + lmb.memory.region[i].size))) {
  85                         return 1;
  86                 }
  87         }
  88
  89         return 0;
  90 #endif
  91 }
  92 EXPORT_SYMBOL(page_is_ram);
  93
  94 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  95                               unsigned long size, pgprot_t vma_prot)
  96 {
  97         if (ppc_md.phys_mem_access_prot)
  98                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  99
 100         if (!page_is_ram(pfn))
 101                 vma_prot = __pgprot(pgprot_val(vma_prot)
 102                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
 103         return vma_prot;
 104 }
 105 EXPORT_SYMBOL(phys_mem_access_prot);
 106
 107 #ifdef CONFIG_MEMORY_HOTPLUG
 108
 109 void online_page(struct page *page)
 110 {
 111         ClearPageReserved(page);
 112         init_page_count(page);
 113         __free_page(page);
 114         totalram_pages++;
 115         num_physpages++;
 116 }
 117
 118 int __devinit add_memory(u64 start, u64 size)
 119 {
 120         struct pglist_data *pgdata;
 121         struct zone *zone;
 122         int nid;
 123         unsigned long start_pfn = start >> PAGE_SHIFT;
 124         unsigned long nr_pages = size >> PAGE_SHIFT;
 125
 126         nid = hot_add_scn_to_nid(start);
 127         pgdata = NODE_DATA(nid);
 128
 129         start = (unsigned long)__va(start);
 130         create_section_mapping(start, start + size);
 131
 132         /* this should work for most non-highmem platforms */
 133         zone = pgdata->node_zones;
 134
 135         return __add_pages(zone, start_pfn, nr_pages);
 136
 137         return 0;
 138 }
 139
 140 /*
 141  * First pass at this code will check to determine if the remove
 142  * request is within the RMO.  Do not allow removal within the RMO.
 143  */
 144 int __devinit remove_memory(u64 start, u64 size)
 145 {
 146         struct zone *zone;
 147         unsigned long start_pfn, end_pfn, nr_pages;
 148
 149         start_pfn = start >> PAGE_SHIFT;
 150         nr_pages = size >> PAGE_SHIFT;
 151         end_pfn = start_pfn + nr_pages;
 152
 153         printk("%s(): Attempting to remove memoy in range "
 154                         "%lx to %lx\n", __func__, start, start+size);
 155         /*
 156          * check for range within RMO
 157          */
 158         zone = page_zone(pfn_to_page(start_pfn));
 159
 160         printk("%s(): memory will be removed from "
 161                         "the %s zone\n", __func__, zone->name);
 162
 163         /*
 164          * not handling removing memory ranges that
 165          * overlap multiple zones yet
 166          */
 167         if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
 168                 goto overlap;
 169
 170         /* make sure it is NOT in RMO */
 171         if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
 172                 printk("%s(): range to be removed must NOT be in RMO!\n",
 173                         __func__);
 174                 goto in_rmo;
 175         }
 176
 177         return __remove_pages(zone, start_pfn, nr_pages);
 178
 179 overlap:
 180         printk("%s(): memory range to be removed overlaps "
 181                 "multiple zones!!!\n", __func__);
 182 in_rmo:
 183         return -1;
 184 }
 185 #endif /* CONFIG_MEMORY_HOTPLUG */
 186
 187 void show_mem(void)
 188 {
 189         unsigned long total = 0, reserved = 0;
 190         unsigned long shared = 0, cached = 0;
 191         unsigned long highmem = 0;
 192         struct page *page;
 193         pg_data_t *pgdat;
 194         unsigned long i;
 195
 196         printk("Mem-info:\n");
 197         show_free_areas();
 198         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 199         for_each_online_pgdat(pgdat) {
 200                 unsigned long flags;
 201                 pgdat_resize_lock(pgdat, &flags);
 202                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 203                         if (!pfn_valid(pgdat->node_start_pfn + i))
 204                                 continue;
 205                         page = pgdat_page_nr(pgdat, i);
 206                         total++;
 207                         if (PageHighMem(page))
 208                                 highmem++;
 209                         if (PageReserved(page))
 210                                 reserved++;
 211                         else if (PageSwapCache(page))
 212                                 cached++;
 213                         else if (page_count(page))
 214                                 shared += page_count(page) - 1;
 215                 }
 216                 pgdat_resize_unlock(pgdat, &flags);
 217         }
 218         printk("%ld pages of RAM\n", total);
 219 #ifdef CONFIG_HIGHMEM
 220         printk("%ld pages of HIGHMEM\n", highmem);
 221 #endif
 222         printk("%ld reserved pages\n", reserved);
 223         printk("%ld pages shared\n", shared);
 224         printk("%ld pages swap cached\n", cached);
 225 }
 226
 227 /*
 228  * Initialize the bootmem system and give it all the memory we
 229  * have available.  If we are using highmem, we only put the
 230  * lowmem into the bootmem system.
 231  */
 232 #ifndef CONFIG_NEED_MULTIPLE_NODES
 233 void __init do_init_bootmem(void)
 234 {
 235         unsigned long i;
 236         unsigned long start, bootmap_pages;
 237         unsigned long total_pages;
 238         int boot_mapsize;
 239
 240         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 241 #ifdef CONFIG_HIGHMEM
 242         total_pages = total_lowmem >> PAGE_SHIFT;
 243 #endif
 244
 245         /*
 246          * Find an area to use for the bootmem bitmap.  Calculate the size of
 247          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 248          * Add 1 additional page in case the address isn't page-aligned.
 249          */
 250         bootmap_pages = bootmem_bootmap_pages(total_pages);
 251
 252         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 253
 254         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 255
 256         /* Add all physical memory to the bootmem map, mark each area
 257          * present.
 258          */
 259         for (i = 0; i < lmb.memory.cnt; i++) {
 260                 unsigned long base = lmb.memory.region[i].base;
 261                 unsigned long size = lmb_size_bytes(&lmb.memory, i);
 262 #ifdef CONFIG_HIGHMEM
 263                 if (base >= total_lowmem)
 264                         continue;
 265                 if (base + size > total_lowmem)
 266                         size = total_lowmem - base;
 267 #endif
 268                 free_bootmem(base, size);
 269         }
 270
 271         /* reserve the sections we're already using */
 272         for (i = 0; i < lmb.reserved.cnt; i++)
 273                 reserve_bootmem(lmb.reserved.region[i].base,
 274                                 lmb_size_bytes(&lmb.reserved, i));
 275
 276         /* XXX need to clip this if using highmem? */
 277         for (i = 0; i < lmb.memory.cnt; i++)
 278                 memory_present(0, lmb_start_pfn(&lmb.memory, i),
 279                                lmb_end_pfn(&lmb.memory, i));
 280         init_bootmem_done = 1;
 281 }
 282
 283 /*
 284  * paging_init() sets up the page tables - in fact we've already done this.
 285  */
 286 void __init paging_init(void)
 287 {
 288         unsigned long zones_size[MAX_NR_ZONES];
 289         unsigned long zholes_size[MAX_NR_ZONES];
 290         unsigned long total_ram = lmb_phys_mem_size();
 291         unsigned long top_of_ram = lmb_end_of_DRAM();
 292
 293 #ifdef CONFIG_HIGHMEM
 294         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 295         pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
 296                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 297         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 298         kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
 299                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
 300         kmap_prot = PAGE_KERNEL;
 301 #endif /* CONFIG_HIGHMEM */
 302
 303         printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 304                top_of_ram, total_ram);
 305         printk(KERN_INFO "Memory hole size: %ldMB\n",
 306                (top_of_ram - total_ram) >> 20);
 307         /*
 308          * All pages are DMA-able so we put them all in the DMA zone.
 309          */
 310         memset(zones_size, 0, sizeof(zones_size));
 311         memset(zholes_size, 0, sizeof(zholes_size));
 312
 313         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 314         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 315
 316 #ifdef CONFIG_HIGHMEM
 317         zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 318         zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
 319         zholes_size[ZONE_HIGHMEM] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 320 #else
 321         zones_size[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 322         zholes_size[ZONE_DMA] = (top_of_ram - total_ram) >> PAGE_SHIFT;
 323 #endif /* CONFIG_HIGHMEM */
 324
 325         free_area_init_node(0, NODE_DATA(0), zones_size,
 326                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 327 }
 328 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 329
 330 void __init mem_init(void)
 331 {
 332 #ifdef CONFIG_NEED_MULTIPLE_NODES
 333         int nid;
 334 #endif
 335         pg_data_t *pgdat;
 336         unsigned long i;
 337         struct page *page;
 338         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 339
 340         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 341         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 342
 343 #ifdef CONFIG_NEED_MULTIPLE_NODES
 344         for_each_online_node(nid) {
 345                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 346                         printk("freeing bootmem node %d\n", nid);
 347                         totalram_pages +=
 348                                 free_all_bootmem_node(NODE_DATA(nid));
 349                 }
 350         }
 351 #else
 352         max_mapnr = max_pfn;
 353         totalram_pages += free_all_bootmem();
 354 #endif
 355
 356 #ifdef CONFIG_PPC_PSERIES
 357         /* Mark the RTAS pages as PG_reserved so userspace can mmap them */
 358         if (rtas_rmo_buf) {
 359                 unsigned long pfn, start_pfn, end_pfn;
 360
 361                 start_pfn = rtas_rmo_buf >> PAGE_SHIFT;
 362                 end_pfn = (rtas_rmo_buf + RTAS_RMOBUF_MAX) >>  PAGE_SHIFT;
 363                 for (pfn = start_pfn; pfn < end_pfn; pfn++)
 364                         SetPageReserved(pfn_to_page(pfn));
 365         }
 366 #endif
 367
 368         for_each_online_pgdat(pgdat) {
 369                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 370                         if (!pfn_valid(pgdat->node_start_pfn + i))
 371                                 continue;
 372                         page = pgdat_page_nr(pgdat, i);
 373                         if (PageReserved(page))
 374                                 reservedpages++;
 375                 }
 376         }
 377
 378         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 379         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 380         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 381         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 382
 383 #ifdef CONFIG_HIGHMEM
 384         {
 385                 unsigned long pfn, highmem_mapnr;
 386
 387                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 388                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 389                         struct page *page = pfn_to_page(pfn);
 390
 391                         ClearPageReserved(page);
 392                         init_page_count(page);
 393                         __free_page(page);
 394                         totalhigh_pages++;
 395                 }
 396                 totalram_pages += totalhigh_pages;
 397                 printk(KERN_INFO "High memory: %luk\n",
 398                        totalhigh_pages << (PAGE_SHIFT-10));
 399         }
 400 #endif /* CONFIG_HIGHMEM */
 401
 402         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 403                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 404                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 405                 num_physpages << (PAGE_SHIFT-10),
 406                 codesize >> 10,
 407                 reservedpages << (PAGE_SHIFT-10),
 408                 datasize >> 10,
 409                 bsssize >> 10,
 410                 initsize >> 10);
 411
 412         mem_init_done = 1;
 413
 414         /* Initialize the vDSO */
 415         vdso_init();
 416 }
 417
 418 /*
 419  * This is called when a page has been modified by the kernel.
 420  * It just marks the page as not i-cache clean.  We do the i-cache
 421  * flush later when the page is given to a user process, if necessary.
 422  */
 423 void flush_dcache_page(struct page *page)
 424 {
 425         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 426                 return;
 427         /* avoid an atomic op if possible */
 428         if (test_bit(PG_arch_1, &page->flags))
 429                 clear_bit(PG_arch_1, &page->flags);
 430 }
 431 EXPORT_SYMBOL(flush_dcache_page);
 432
 433 void flush_dcache_icache_page(struct page *page)
 434 {
 435 #ifdef CONFIG_BOOKE
 436         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 437         __flush_dcache_icache(start);
 438         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 439 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 440         /* On 8xx there is no need to kmap since highmem is not supported */
 441         __flush_dcache_icache(page_address(page));
 442 #else
 443         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 444 #endif
 445
 446 }
 447 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 448 {
 449         clear_page(page);
 450
 451         /*
 452          * We shouldnt have to do this, but some versions of glibc
 453          * require it (ld.so assumes zero filled pages are icache clean)
 454          * - Anton
 455          */
 456         flush_dcache_page(pg);
 457 }
 458 EXPORT_SYMBOL(clear_user_page);
 459
 460 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 461                     struct page *pg)
 462 {
 463         copy_page(vto, vfrom);
 464
 465         /*
 466          * We should be able to use the following optimisation, however
 467          * there are two problems.
 468          * Firstly a bug in some versions of binutils meant PLT sections
 469          * were not marked executable.
 470          * Secondly the first word in the GOT section is blrl, used
 471          * to establish the GOT address. Until recently the GOT was
 472          * not marked executable.
 473          * - Anton
 474          */
 475 #if 0
 476         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 477                 return;
 478 #endif
 479
 480         flush_dcache_page(pg);
 481 }
 482
 483 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 484                              unsigned long addr, int len)
 485 {
 486         unsigned long maddr;
 487
 488         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 489         flush_icache_range(maddr, maddr + len);
 490         kunmap(page);
 491 }
 492 EXPORT_SYMBOL(flush_icache_user_range);
 493
 494 /*
 495  * This is called at the end of handling a user page fault, when the
 496  * fault has been handled by updating a PTE in the linux page tables.
 497  * We use it to preload an HPTE into the hash table corresponding to
 498  * the updated linux PTE.
 499  *
 500  * This must always be called with the pte lock held.
 501  */
 502 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 503                       pte_t pte)
 504 {
 505 #ifdef CONFIG_PPC_STD_MMU
 506         unsigned long access = 0, trap;
 507 #endif
 508         unsigned long pfn = pte_pfn(pte);
 509
 510         /* handle i-cache coherency */
 511         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 512             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 513             pfn_valid(pfn)) {
 514                 struct page *page = pfn_to_page(pfn);
 515                 if (!PageReserved(page)
 516                     && !test_bit(PG_arch_1, &page->flags)) {
 517                         if (vma->vm_mm == current->active_mm) {
 518 #ifdef CONFIG_8xx
 519                         /* On 8xx, cache control instructions (particularly
 520                          * "dcbst" from flush_dcache_icache) fault as write
 521                          * operation if there is an unpopulated TLB entry
 522                          * for the address in question. To workaround that,
 523                          * we invalidate the TLB here, thus avoiding dcbst
 524                          * misbehaviour.
 525                          */
 526                                 _tlbie(address);
 527 #endif
 528                                 __flush_dcache_icache((void *) address);
 529                         } else
 530                                 flush_dcache_icache_page(page);
 531                         set_bit(PG_arch_1, &page->flags);
 532                 }
 533         }
 534
 535 #ifdef CONFIG_PPC_STD_MMU
 536         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 537         if (!pte_young(pte) || address >= TASK_SIZE)
 538                 return;
 539
 540         /* We try to figure out if we are coming from an instruction
 541          * access fault and pass that down to __hash_page so we avoid
 542          * double-faulting on execution of fresh text. We have to test
 543          * for regs NULL since init will get here first thing at boot
 544          *
 545          * We also avoid filling the hash if not coming from a fault
 546          */
 547         if (current->thread.regs == NULL)
 548                 return;
 549         trap = TRAP(current->thread.regs);
 550         if (trap == 0x400)
 551                 access |= _PAGE_EXEC;
 552         else if (trap != 0x300)
 553                 return;
 554         hash_preload(vma->vm_mm, address, access, trap);
 555 #endif /* CONFIG_PPC_STD_MMU */
 556 }