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/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 int page_is_ram(unsigned long pfn)
  62 {
  63         unsigned long paddr = (pfn << PAGE_SHIFT);
  64
  65 #ifndef CONFIG_PPC64    /* XXX for now */
  66         return paddr < __pa(high_memory);
  67 #else
  68         int i;
  69         for (i=0; i < lmb.memory.cnt; i++) {
  70                 unsigned long base;
  71
  72                 base = lmb.memory.region[i].base;
  73
  74                 if ((paddr >= base) &&
  75                         (paddr < (base + lmb.memory.region[i].size))) {
  76                         return 1;
  77                 }
  78         }
  79
  80         return 0;
  81 #endif
  82 }
  83
  84 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  85                               unsigned long size, pgprot_t vma_prot)
  86 {
  87         if (ppc_md.phys_mem_access_prot)
  88                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  89
  90         if (!page_is_ram(pfn))
  91                 vma_prot = __pgprot(pgprot_val(vma_prot)
  92                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
  93         return vma_prot;
  94 }
  95 EXPORT_SYMBOL(phys_mem_access_prot);
  96
  97 #ifdef CONFIG_MEMORY_HOTPLUG
  98
  99 void online_page(struct page *page)
 100 {
 101         ClearPageReserved(page);
 102         init_page_count(page);
 103         __free_page(page);
 104         totalram_pages++;
 105         num_physpages++;
 106 }
 107
 108 #ifdef CONFIG_NUMA
 109 int memory_add_physaddr_to_nid(u64 start)
 110 {
 111         return hot_add_scn_to_nid(start);
 112 }
 113 #endif
 114
 115 int __devinit arch_add_memory(int nid, u64 start, u64 size)
 116 {
 117         struct pglist_data *pgdata;
 118         struct zone *zone;
 119         unsigned long start_pfn = start >> PAGE_SHIFT;
 120         unsigned long nr_pages = size >> PAGE_SHIFT;
 121
 122         pgdata = NODE_DATA(nid);
 123
 124         start = (unsigned long)__va(start);
 125         create_section_mapping(start, start + size);
 126
 127         /* this should work for most non-highmem platforms */
 128         zone = pgdata->node_zones;
 129
 130         return __add_pages(zone, start_pfn, nr_pages);
 131 }
 132
 133 /*
 134  * First pass at this code will check to determine if the remove
 135  * request is within the RMO.  Do not allow removal within the RMO.
 136  */
 137 int __devinit remove_memory(u64 start, u64 size)
 138 {
 139         struct zone *zone;
 140         unsigned long start_pfn, end_pfn, nr_pages;
 141
 142         start_pfn = start >> PAGE_SHIFT;
 143         nr_pages = size >> PAGE_SHIFT;
 144         end_pfn = start_pfn + nr_pages;
 145
 146         printk("%s(): Attempting to remove memoy in range "
 147                         "%lx to %lx\n", __func__, start, start+size);
 148         /*
 149          * check for range within RMO
 150          */
 151         zone = page_zone(pfn_to_page(start_pfn));
 152
 153         printk("%s(): memory will be removed from "
 154                         "the %s zone\n", __func__, zone->name);
 155
 156         /*
 157          * not handling removing memory ranges that
 158          * overlap multiple zones yet
 159          */
 160         if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
 161                 goto overlap;
 162
 163         /* make sure it is NOT in RMO */
 164         if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
 165                 printk("%s(): range to be removed must NOT be in RMO!\n",
 166                         __func__);
 167                 goto in_rmo;
 168         }
 169
 170         return __remove_pages(zone, start_pfn, nr_pages);
 171
 172 overlap:
 173         printk("%s(): memory range to be removed overlaps "
 174                 "multiple zones!!!\n", __func__);
 175 in_rmo:
 176         return -1;
 177 }
 178 #endif /* CONFIG_MEMORY_HOTPLUG */
 179
 180 void show_mem(void)
 181 {
 182         unsigned long total = 0, reserved = 0;
 183         unsigned long shared = 0, cached = 0;
 184         unsigned long highmem = 0;
 185         struct page *page;
 186         pg_data_t *pgdat;
 187         unsigned long i;
 188
 189         printk("Mem-info:\n");
 190         show_free_areas();
 191         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 192         for_each_online_pgdat(pgdat) {
 193                 unsigned long flags;
 194                 pgdat_resize_lock(pgdat, &flags);
 195                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 196                         if (!pfn_valid(pgdat->node_start_pfn + i))
 197                                 continue;
 198                         page = pgdat_page_nr(pgdat, i);
 199                         total++;
 200                         if (PageHighMem(page))
 201                                 highmem++;
 202                         if (PageReserved(page))
 203                                 reserved++;
 204                         else if (PageSwapCache(page))
 205                                 cached++;
 206                         else if (page_count(page))
 207                                 shared += page_count(page) - 1;
 208                 }
 209                 pgdat_resize_unlock(pgdat, &flags);
 210         }
 211         printk("%ld pages of RAM\n", total);
 212 #ifdef CONFIG_HIGHMEM
 213         printk("%ld pages of HIGHMEM\n", highmem);
 214 #endif
 215         printk("%ld reserved pages\n", reserved);
 216         printk("%ld pages shared\n", shared);
 217         printk("%ld pages swap cached\n", cached);
 218 }
 219
 220 /*
 221  * Initialize the bootmem system and give it all the memory we
 222  * have available.  If we are using highmem, we only put the
 223  * lowmem into the bootmem system.
 224  */
 225 #ifndef CONFIG_NEED_MULTIPLE_NODES
 226 void __init do_init_bootmem(void)
 227 {
 228         unsigned long i;
 229         unsigned long start, bootmap_pages;
 230         unsigned long total_pages;
 231         int boot_mapsize;
 232
 233         max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 234 #ifdef CONFIG_HIGHMEM
 235         total_pages = total_lowmem >> PAGE_SHIFT;
 236 #endif
 237
 238         /*
 239          * Find an area to use for the bootmem bitmap.  Calculate the size of
 240          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 241          * Add 1 additional page in case the address isn't page-aligned.
 242          */
 243         bootmap_pages = bootmem_bootmap_pages(total_pages);
 244
 245         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 246
 247         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 248
 249         /* Add active regions with valid PFNs */
 250         for (i = 0; i < lmb.memory.cnt; i++) {
 251                 unsigned long start_pfn, end_pfn;
 252                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 253                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 254                 add_active_range(0, start_pfn, end_pfn);
 255         }
 256
 257         /* Add all physical memory to the bootmem map, mark each area
 258          * present.
 259          */
 260 #ifdef CONFIG_HIGHMEM
 261         free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);
 262 #else
 263         free_bootmem_with_active_regions(0, max_pfn);
 264 #endif
 265
 266         /* reserve the sections we're already using */
 267         for (i = 0; i < lmb.reserved.cnt; i++)
 268                 reserve_bootmem(lmb.reserved.region[i].base,
 269                                 lmb_size_bytes(&lmb.reserved, i));
 270
 271         /* XXX need to clip this if using highmem? */
 272         sparse_memory_present_with_active_regions(0);
 273
 274         init_bootmem_done = 1;
 275 }
 276
 277 /* mark pages that don't exist as nosave */
 278 static int __init mark_nonram_nosave(void)
 279 {
 280         unsigned long lmb_next_region_start_pfn,
 281                       lmb_region_max_pfn;
 282         int i;
 283
 284         for (i = 0; i < lmb.memory.cnt - 1; i++) {
 285                 lmb_region_max_pfn =
 286                         (lmb.memory.region[i].base >> PAGE_SHIFT) +
 287                         (lmb.memory.region[i].size >> PAGE_SHIFT);
 288                 lmb_next_region_start_pfn =
 289                         lmb.memory.region[i+1].base >> PAGE_SHIFT;
 290
 291                 if (lmb_region_max_pfn < lmb_next_region_start_pfn)
 292                         register_nosave_region(lmb_region_max_pfn,
 293                                                lmb_next_region_start_pfn);
 294         }
 295
 296         return 0;
 297 }
 298
 299 /*
 300  * paging_init() sets up the page tables - in fact we've already done this.
 301  */
 302 void __init paging_init(void)
 303 {
 304         unsigned long total_ram = lmb_phys_mem_size();
 305         unsigned long top_of_ram = lmb_end_of_DRAM();
 306         unsigned long max_zone_pfns[MAX_NR_ZONES];
 307
 308 #ifdef CONFIG_HIGHMEM
 309         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 310         pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 311                         (PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 312         map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
 313         kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 314                         (KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
 315                          KMAP_FIX_BEGIN);
 316         kmap_prot = PAGE_KERNEL;
 317 #endif /* CONFIG_HIGHMEM */
 318
 319         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 320                top_of_ram, total_ram);
 321         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 322                (top_of_ram - total_ram) >> 20);
 323         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 324 #ifdef CONFIG_HIGHMEM
 325         max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 326         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 327 #else
 328         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 329 #endif
 330         free_area_init_nodes(max_zone_pfns);
 331
 332         mark_nonram_nosave();
 333 }
 334 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 335
 336 void __init mem_init(void)
 337 {
 338 #ifdef CONFIG_NEED_MULTIPLE_NODES
 339         int nid;
 340 #endif
 341         pg_data_t *pgdat;
 342         unsigned long i;
 343         struct page *page;
 344         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 345
 346         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 347         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 348
 349 #ifdef CONFIG_NEED_MULTIPLE_NODES
 350         for_each_online_node(nid) {
 351                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 352                         printk("freeing bootmem node %d\n", nid);
 353                         totalram_pages +=
 354                                 free_all_bootmem_node(NODE_DATA(nid));
 355                 }
 356         }
 357 #else
 358         max_mapnr = max_pfn;
 359         totalram_pages += free_all_bootmem();
 360 #endif
 361         for_each_online_pgdat(pgdat) {
 362                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 363                         if (!pfn_valid(pgdat->node_start_pfn + i))
 364                                 continue;
 365                         page = pgdat_page_nr(pgdat, i);
 366                         if (PageReserved(page))
 367                                 reservedpages++;
 368                 }
 369         }
 370
 371         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 372         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 373         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 374         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 375
 376 #ifdef CONFIG_HIGHMEM
 377         {
 378                 unsigned long pfn, highmem_mapnr;
 379
 380                 highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 381                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 382                         struct page *page = pfn_to_page(pfn);
 383
 384                         ClearPageReserved(page);
 385                         init_page_count(page);
 386                         __free_page(page);
 387                         totalhigh_pages++;
 388                 }
 389                 totalram_pages += totalhigh_pages;
 390                 printk(KERN_DEBUG "High memory: %luk\n",
 391                        totalhigh_pages << (PAGE_SHIFT-10));
 392         }
 393 #endif /* CONFIG_HIGHMEM */
 394
 395         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 396                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 397                 (unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 398                 num_physpages << (PAGE_SHIFT-10),
 399                 codesize >> 10,
 400                 reservedpages << (PAGE_SHIFT-10),
 401                 datasize >> 10,
 402                 bsssize >> 10,
 403                 initsize >> 10);
 404
 405         mem_init_done = 1;
 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 #ifdef CONFIG_8xx
 506                 /* On 8xx, cache control instructions (particularly
 507                  * "dcbst" from flush_dcache_icache) fault as write
 508                  * operation if there is an unpopulated TLB entry
 509                  * for the address in question. To workaround that,
 510                  * we invalidate the TLB here, thus avoiding dcbst
 511                  * misbehaviour.
 512                  */
 513                 _tlbie(address);
 514 #endif
 515                 if (!PageReserved(page)
 516                     && !test_bit(PG_arch_1, &page->flags)) {
 517                         if (vma->vm_mm == current->active_mm) {
 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 }