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 #ifdef CONFIG_MEMORY_HOTREMOVE
 133 int remove_memory(u64 start, u64 size)
 134 {
 135         unsigned long start_pfn, end_pfn;
 136         int ret;
 137
 138         start_pfn = start >> PAGE_SHIFT;
 139         end_pfn = start_pfn + (size >> PAGE_SHIFT);
 140         ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
 141         if (ret)
 142                 goto out;
 143         /* Arch-specific calls go here - next patch */
 144 out:
 145         return ret;
 146 }
 147 #endif /* CONFIG_MEMORY_HOTREMOVE */
 148
 149 /*
 150  * walk_memory_resource() needs to make sure there is no holes in a given
 151  * memory range. On PPC64, since this range comes from /sysfs, the range
 152  * is guaranteed to be valid, non-overlapping and can not contain any
 153  * holes. By the time we get here (memory add or remove), /proc/device-tree
 154  * is updated and correct. Only reason we need to check against device-tree
 155  * would be if we allow user-land to specify a memory range through a
 156  * system call/ioctl etc. instead of doing offline/online through /sysfs.
 157  */
 158 int
 159 walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
 160                         int (*func)(unsigned long, unsigned long, void *))
 161 {
 162         return  (*func)(start_pfn, nr_pages, arg);
 163 }
 164
 165 #endif /* CONFIG_MEMORY_HOTPLUG */
 166
 167 void show_mem(void)
 168 {
 169         unsigned long total = 0, reserved = 0;
 170         unsigned long shared = 0, cached = 0;
 171         unsigned long highmem = 0;
 172         struct page *page;
 173         pg_data_t *pgdat;
 174         unsigned long i;
 175
 176         printk("Mem-info:\n");
 177         show_free_areas();
 178         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 179         for_each_online_pgdat(pgdat) {
 180                 unsigned long flags;
 181                 pgdat_resize_lock(pgdat, &flags);
 182                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 183                         if (!pfn_valid(pgdat->node_start_pfn + i))
 184                                 continue;
 185                         page = pgdat_page_nr(pgdat, i);
 186                         total++;
 187                         if (PageHighMem(page))
 188                                 highmem++;
 189                         if (PageReserved(page))
 190                                 reserved++;
 191                         else if (PageSwapCache(page))
 192                                 cached++;
 193                         else if (page_count(page))
 194                                 shared += page_count(page) - 1;
 195                 }
 196                 pgdat_resize_unlock(pgdat, &flags);
 197         }
 198         printk("%ld pages of RAM\n", total);
 199 #ifdef CONFIG_HIGHMEM
 200         printk("%ld pages of HIGHMEM\n", highmem);
 201 #endif
 202         printk("%ld reserved pages\n", reserved);
 203         printk("%ld pages shared\n", shared);
 204         printk("%ld pages swap cached\n", cached);
 205 }
 206
 207 /*
 208  * Initialize the bootmem system and give it all the memory we
 209  * have available.  If we are using highmem, we only put the
 210  * lowmem into the bootmem system.
 211  */
 212 #ifndef CONFIG_NEED_MULTIPLE_NODES
 213 void __init do_init_bootmem(void)
 214 {
 215         unsigned long i;
 216         unsigned long start, bootmap_pages;
 217         unsigned long total_pages;
 218         int boot_mapsize;
 219
 220         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 221 #ifdef CONFIG_HIGHMEM
 222         total_pages = total_lowmem >> PAGE_SHIFT;
 223 #endif
 224
 225         /*
 226          * Find an area to use for the bootmem bitmap.  Calculate the size of
 227          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 228          * Add 1 additional page in case the address isn't page-aligned.
 229          */
 230         bootmap_pages = bootmem_bootmap_pages(total_pages);
 231
 232         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 233
 234         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 235
 236         /* Add active regions with valid PFNs */
 237         for (i = 0; i < lmb.memory.cnt; i++) {
 238                 unsigned long start_pfn, end_pfn;
 239                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 240                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 241                 add_active_range(0, start_pfn, end_pfn);
 242         }
 243
 244         /* Add all physical memory to the bootmem map, mark each area
 245          * present.
 246          */
 247 #ifdef CONFIG_HIGHMEM
 248         free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);
 249
 250         /* reserve the sections we're already using */
 251         for (i = 0; i < lmb.reserved.cnt; i++) {
 252                 unsigned long addr = lmb.reserved.region[i].base +
 253                                      lmb_size_bytes(&lmb.reserved, i) - 1;
 254                 if (addr < total_lowmem)
 255                         reserve_bootmem(lmb.reserved.region[i].base,
 256                                         lmb_size_bytes(&lmb.reserved, i),
 257                                         BOOTMEM_DEFAULT);
 258                 else if (lmb.reserved.region[i].base < total_lowmem) {
 259                         unsigned long adjusted_size = total_lowmem -
 260                                       lmb.reserved.region[i].base;
 261                         reserve_bootmem(lmb.reserved.region[i].base,
 262                                         adjusted_size, BOOTMEM_DEFAULT);
 263                 }
 264         }
 265 #else
 266         free_bootmem_with_active_regions(0, max_pfn);
 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                                 BOOTMEM_DEFAULT);
 273
 274 #endif
 275         /* XXX need to clip this if using highmem? */
 276         sparse_memory_present_with_active_regions(0);
 277
 278         init_bootmem_done = 1;
 279 }
 280
 281 /* mark pages that don't exist as nosave */
 282 static int __init mark_nonram_nosave(void)
 283 {
 284         unsigned long lmb_next_region_start_pfn,
 285                       lmb_region_max_pfn;
 286         int i;
 287
 288         for (i = 0; i < lmb.memory.cnt - 1; i++) {
 289                 lmb_region_max_pfn =
 290                         (lmb.memory.region[i].base >> PAGE_SHIFT) +
 291                         (lmb.memory.region[i].size >> PAGE_SHIFT);
 292                 lmb_next_region_start_pfn =
 293                         lmb.memory.region[i+1].base >> PAGE_SHIFT;
 294
 295                 if (lmb_region_max_pfn < lmb_next_region_start_pfn)
 296                         register_nosave_region(lmb_region_max_pfn,
 297                                                lmb_next_region_start_pfn);
 298         }
 299
 300         return 0;
 301 }
 302
 303 /*
 304  * paging_init() sets up the page tables - in fact we've already done this.
 305  */
 306 void __init paging_init(void)
 307 {
 308         unsigned long total_ram = lmb_phys_mem_size();
 309         unsigned long top_of_ram = lmb_end_of_DRAM();
 310         unsigned long max_zone_pfns[MAX_NR_ZONES];
 311
 312 #ifdef CONFIG_HIGHMEM
 313         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 314         pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 315                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 316         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 317         kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 318                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
 319                          KMAP_FIX_BEGIN);
 320         kmap_prot = PAGE_KERNEL;
 321 #endif /* CONFIG_HIGHMEM */
 322
 323         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 324                top_of_ram, total_ram);
 325         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 326                (top_of_ram - total_ram) >> 20);
 327         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 328 #ifdef CONFIG_HIGHMEM
 329         max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 330         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 331 #else
 332         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 333 #endif
 334         free_area_init_nodes(max_zone_pfns);
 335
 336         mark_nonram_nosave();
 337 }
 338 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 339
 340 void __init mem_init(void)
 341 {
 342 #ifdef CONFIG_NEED_MULTIPLE_NODES
 343         int nid;
 344 #endif
 345         pg_data_t *pgdat;
 346         unsigned long i;
 347         struct page *page;
 348         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 349
 350         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 351         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 352
 353 #ifdef CONFIG_NEED_MULTIPLE_NODES
 354         for_each_online_node(nid) {
 355                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 356                         printk("freeing bootmem node %d\n", nid);
 357                         totalram_pages +=
 358                                 free_all_bootmem_node(NODE_DATA(nid));
 359                 }
 360         }
 361 #else
 362         max_mapnr = max_pfn;
 363         totalram_pages += free_all_bootmem();
 364 #endif
 365         for_each_online_pgdat(pgdat) {
 366                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 367                         if (!pfn_valid(pgdat->node_start_pfn + i))
 368                                 continue;
 369                         page = pgdat_page_nr(pgdat, i);
 370                         if (PageReserved(page))
 371                                 reservedpages++;
 372                 }
 373         }
 374
 375         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 376         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 377         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 378         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 379
 380 #ifdef CONFIG_HIGHMEM
 381         {
 382                 unsigned long pfn, highmem_mapnr;
 383
 384                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 385                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 386                         struct page *page = pfn_to_page(pfn);
 387                         if (lmb_is_reserved(pfn << PAGE_SHIFT))
 388                                 continue;
 389                         ClearPageReserved(page);
 390                         init_page_count(page);
 391                         __free_page(page);
 392                         totalhigh_pages++;
 393                         reservedpages--;
 394                 }
 395                 totalram_pages += totalhigh_pages;
 396                 printk(KERN_DEBUG "High memory: %luk\n",
 397                        totalhigh_pages << (PAGE_SHIFT-10));
 398         }
 399 #endif /* CONFIG_HIGHMEM */
 400
 401         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 402                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 403                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 404                 num_physpages << (PAGE_SHIFT-10),
 405                 codesize >> 10,
 406                 reservedpages << (PAGE_SHIFT-10),
 407                 datasize >> 10,
 408                 bsssize >> 10,
 409                 initsize >> 10);
 410
 411         mem_init_done = 1;
 412 }
 413
 414 /*
 415  * This is called when a page has been modified by the kernel.
 416  * It just marks the page as not i-cache clean.  We do the i-cache
 417  * flush later when the page is given to a user process, if necessary.
 418  */
 419 void flush_dcache_page(struct page *page)
 420 {
 421         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 422                 return;
 423         /* avoid an atomic op if possible */
 424         if (test_bit(PG_arch_1, &page->flags))
 425                 clear_bit(PG_arch_1, &page->flags);
 426 }
 427 EXPORT_SYMBOL(flush_dcache_page);
 428
 429 void flush_dcache_icache_page(struct page *page)
 430 {
 431 #ifdef CONFIG_BOOKE
 432         void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 433         __flush_dcache_icache(start);
 434         kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 435 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 436         /* On 8xx there is no need to kmap since highmem is not supported */
 437         __flush_dcache_icache(page_address(page));
 438 #else
 439         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 440 #endif
 441
 442 }
 443 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 444 {
 445         clear_page(page);
 446
 447         /*
 448          * We shouldnt have to do this, but some versions of glibc
 449          * require it (ld.so assumes zero filled pages are icache clean)
 450          * - Anton
 451          */
 452         flush_dcache_page(pg);
 453 }
 454 EXPORT_SYMBOL(clear_user_page);
 455
 456 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 457                     struct page *pg)
 458 {
 459         copy_page(vto, vfrom);
 460
 461         /*
 462          * We should be able to use the following optimisation, however
 463          * there are two problems.
 464          * Firstly a bug in some versions of binutils meant PLT sections
 465          * were not marked executable.
 466          * Secondly the first word in the GOT section is blrl, used
 467          * to establish the GOT address. Until recently the GOT was
 468          * not marked executable.
 469          * - Anton
 470          */
 471 #if 0
 472         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 473                 return;
 474 #endif
 475
 476         flush_dcache_page(pg);
 477 }
 478
 479 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 480                              unsigned long addr, int len)
 481 {
 482         unsigned long maddr;
 483
 484         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 485         flush_icache_range(maddr, maddr + len);
 486         kunmap(page);
 487 }
 488 EXPORT_SYMBOL(flush_icache_user_range);
 489
 490 /*
 491  * This is called at the end of handling a user page fault, when the
 492  * fault has been handled by updating a PTE in the linux page tables.
 493  * We use it to preload an HPTE into the hash table corresponding to
 494  * the updated linux PTE.
 495  *
 496  * This must always be called with the pte lock held.
 497  */
 498 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 499                       pte_t pte)
 500 {
 501 #ifdef CONFIG_PPC_STD_MMU
 502         unsigned long access = 0, trap;
 503 #endif
 504         unsigned long pfn = pte_pfn(pte);
 505
 506         /* handle i-cache coherency */
 507         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 508             !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 509             pfn_valid(pfn)) {
 510                 struct page *page = pfn_to_page(pfn);
 511 #ifdef CONFIG_8xx
 512                 /* On 8xx, cache control instructions (particularly
 513                  * "dcbst" from flush_dcache_icache) fault as write
 514                  * operation if there is an unpopulated TLB entry
 515                  * for the address in question. To workaround that,
 516                  * we invalidate the TLB here, thus avoiding dcbst
 517                  * misbehaviour.
 518                  */
 519                 _tlbie(address, 0 /* 8xx doesn't care about PID */);
 520 #endif
 521                 /* The _PAGE_USER test should really be _PAGE_EXEC, but
 522                  * older glibc versions execute some code from no-exec
 523                  * pages, which for now we are supporting.  If exec-only
 524                  * pages are ever implemented, this will have to change.
 525                  */
 526                 if (!PageReserved(page) && (pte_val(pte) & _PAGE_USER)
 527                     && !test_bit(PG_arch_1, &page->flags)) {
 528                         if (vma->vm_mm == current->active_mm) {
 529                                 __flush_dcache_icache((void *) address);
 530                         } else
 531                                 flush_dcache_icache_page(page);
 532                         set_bit(PG_arch_1, &page->flags);
 533                 }
 534         }
 535
 536 #ifdef CONFIG_PPC_STD_MMU
 537         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 538         if (!pte_young(pte) || address >= TASK_SIZE)
 539                 return;
 540
 541         /* We try to figure out if we are coming from an instruction
 542          * access fault and pass that down to __hash_page so we avoid
 543          * double-faulting on execution of fresh text. We have to test
 544          * for regs NULL since init will get here first thing at boot
 545          *
 546          * We also avoid filling the hash if not coming from a fault
 547          */
 548         if (current->thread.regs == NULL)
 549                 return;
 550         trap = TRAP(current->thread.regs);
 551         if (trap == 0x400)
 552                 access |= _PAGE_EXEC;
 553         else if (trap != 0x300)
 554                 return;
 555         hash_preload(vma->vm_mm, address, access, trap);
 556 #endif /* CONFIG_PPC_STD_MMU */
 557 }