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/gfp.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 #include <linux/lmb.h>
  36 #include <linux/hugetlb.h>
  37
  38 #include <asm/pgalloc.h>
  39 #include <asm/prom.h>
  40 #include <asm/io.h>
  41 #include <asm/mmu_context.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/mmu.h>
  44 #include <asm/smp.h>
  45 #include <asm/machdep.h>
  46 #include <asm/btext.h>
  47 #include <asm/tlb.h>
  48 #include <asm/sections.h>
  49 #include <asm/sparsemem.h>
  50 #include <asm/vdso.h>
  51 #include <asm/fixmap.h>
  52 #include <asm/swiotlb.h>
  53
  54 #include "mmu_decl.h"
  55
  56 #ifndef CPU_FTR_COHERENT_ICACHE
  57 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  58 #define CPU_FTR_NOEXECUTE       0
  59 #endif
  60
  61 int init_bootmem_done;
  62 int mem_init_done;
  63 phys_addr_t memory_limit;
  64
  65 #ifdef CONFIG_HIGHMEM
  66 pte_t *kmap_pte;
  67 pgprot_t kmap_prot;
  68
  69 EXPORT_SYMBOL(kmap_prot);
  70 EXPORT_SYMBOL(kmap_pte);
  71
  72 static inline pte_t *virt_to_kpte(unsigned long vaddr)
  73 {
  74         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
  75                         vaddr), vaddr), vaddr);
  76 }
  77 #endif
  78
  79 int page_is_ram(unsigned long pfn)
  80 {
  81 #ifndef CONFIG_PPC64    /* XXX for now */
  82         return pfn < max_pfn;
  83 #else
  84         unsigned long paddr = (pfn << PAGE_SHIFT);
  85         int i;
  86         for (i=0; i < lmb.memory.cnt; i++) {
  87                 unsigned long base;
  88
  89                 base = lmb.memory.region[i].base;
  90
  91                 if ((paddr >= base) &&
  92                         (paddr < (base + lmb.memory.region[i].size))) {
  93                         return 1;
  94                 }
  95         }
  96
  97         return 0;
  98 #endif
  99 }
 100
 101 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 102                               unsigned long size, pgprot_t vma_prot)
 103 {
 104         if (ppc_md.phys_mem_access_prot)
 105                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
 106
 107         if (!page_is_ram(pfn))
 108                 vma_prot = pgprot_noncached(vma_prot);
 109
 110         return vma_prot;
 111 }
 112 EXPORT_SYMBOL(phys_mem_access_prot);
 113
 114 #ifdef CONFIG_MEMORY_HOTPLUG
 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 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(nid, zone, start_pfn, nr_pages);
 139 }
 140 #endif /* CONFIG_MEMORY_HOTPLUG */
 141
 142 /*
 143  * walk_memory_resource() needs to make sure there is no holes in a given
 144  * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
 145  * Instead it maintains it in lmb.memory structures.  Walk through the
 146  * memory regions, find holes and callback for contiguous regions.
 147  */
 148 int
 149 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 150                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 151 {
 152         struct lmb_property res;
 153         unsigned long pfn, len;
 154         u64 end;
 155         int ret = -1;
 156
 157         res.base = (u64) start_pfn << PAGE_SHIFT;
 158         res.size = (u64) nr_pages << PAGE_SHIFT;
 159
 160         end = res.base + res.size - 1;
 161         while ((res.base < end) && (lmb_find(&res) >= 0)) {
 162                 pfn = (unsigned long)(res.base >> PAGE_SHIFT);
 163                 len = (unsigned long)(res.size >> PAGE_SHIFT);
 164                 ret = (*func)(pfn, len, arg);
 165                 if (ret)
 166                         break;
 167                 res.base += (res.size + 1);
 168                 res.size = (end - res.base + 1);
 169         }
 170         return ret;
 171 }
 172 EXPORT_SYMBOL_GPL(walk_system_ram_range);
 173
 174 /*
 175  * Initialize the bootmem system and give it all the memory we
 176  * have available.  If we are using highmem, we only put the
 177  * lowmem into the bootmem system.
 178  */
 179 #ifndef CONFIG_NEED_MULTIPLE_NODES
 180 void __init do_init_bootmem(void)
 181 {
 182         unsigned long i;
 183         unsigned long start, bootmap_pages;
 184         unsigned long total_pages;
 185         int boot_mapsize;
 186
 187         max_low_pfn = max_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
 188         total_pages = (lmb_end_of_DRAM() - memstart_addr) >> PAGE_SHIFT;
 189 #ifdef CONFIG_HIGHMEM
 190         total_pages = total_lowmem >> PAGE_SHIFT;
 191         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
 192 #endif
 193
 194         /*
 195          * Find an area to use for the bootmem bitmap.  Calculate the size of
 196          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 197          * Add 1 additional page in case the address isn't page-aligned.
 198          */
 199         bootmap_pages = bootmem_bootmap_pages(total_pages);
 200
 201         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 202
 203         min_low_pfn = MEMORY_START >> PAGE_SHIFT;
 204         boot_mapsize = init_bootmem_node(NODE_DATA(0), start >> PAGE_SHIFT, min_low_pfn, max_low_pfn);
 205
 206         /* Add active regions with valid PFNs */
 207         for (i = 0; i < lmb.memory.cnt; i++) {
 208                 unsigned long start_pfn, end_pfn;
 209                 start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 210                 end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 211                 add_active_range(0, start_pfn, end_pfn);
 212         }
 213
 214         /* Add all physical memory to the bootmem map, mark each area
 215          * present.
 216          */
 217 #ifdef CONFIG_HIGHMEM
 218         free_bootmem_with_active_regions(0, lowmem_end_addr >> PAGE_SHIFT);
 219
 220         /* reserve the sections we're already using */
 221         for (i = 0; i < lmb.reserved.cnt; i++) {
 222                 unsigned long addr = lmb.reserved.region[i].base +
 223                                      lmb_size_bytes(&lmb.reserved, i) - 1;
 224                 if (addr < lowmem_end_addr)
 225                         reserve_bootmem(lmb.reserved.region[i].base,
 226                                         lmb_size_bytes(&lmb.reserved, i),
 227                                         BOOTMEM_DEFAULT);
 228                 else if (lmb.reserved.region[i].base < lowmem_end_addr) {
 229                         unsigned long adjusted_size = lowmem_end_addr -
 230                                       lmb.reserved.region[i].base;
 231                         reserve_bootmem(lmb.reserved.region[i].base,
 232                                         adjusted_size, BOOTMEM_DEFAULT);
 233                 }
 234         }
 235 #else
 236         free_bootmem_with_active_regions(0, max_pfn);
 237
 238         /* reserve the sections we're already using */
 239         for (i = 0; i < lmb.reserved.cnt; i++)
 240                 reserve_bootmem(lmb.reserved.region[i].base,
 241                                 lmb_size_bytes(&lmb.reserved, i),
 242                                 BOOTMEM_DEFAULT);
 243
 244 #endif
 245         /* XXX need to clip this if using highmem? */
 246         sparse_memory_present_with_active_regions(0);
 247
 248         init_bootmem_done = 1;
 249 }
 250
 251 /* mark pages that don't exist as nosave */
 252 static int __init mark_nonram_nosave(void)
 253 {
 254         unsigned long lmb_next_region_start_pfn,
 255                       lmb_region_max_pfn;
 256         int i;
 257
 258         for (i = 0; i < lmb.memory.cnt - 1; i++) {
 259                 lmb_region_max_pfn =
 260                         (lmb.memory.region[i].base >> PAGE_SHIFT) +
 261                         (lmb.memory.region[i].size >> PAGE_SHIFT);
 262                 lmb_next_region_start_pfn =
 263                         lmb.memory.region[i+1].base >> PAGE_SHIFT;
 264
 265                 if (lmb_region_max_pfn < lmb_next_region_start_pfn)
 266                         register_nosave_region(lmb_region_max_pfn,
 267                                                lmb_next_region_start_pfn);
 268         }
 269
 270         return 0;
 271 }
 272
 273 /*
 274  * paging_init() sets up the page tables - in fact we've already done this.
 275  */
 276 void __init paging_init(void)
 277 {
 278         unsigned long total_ram = lmb_phys_mem_size();
 279         phys_addr_t top_of_ram = lmb_end_of_DRAM();
 280         unsigned long max_zone_pfns[MAX_NR_ZONES];
 281
 282 #ifdef CONFIG_PPC32
 283         unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
 284         unsigned long end = __fix_to_virt(FIX_HOLE);
 285
 286         for (; v < end; v += PAGE_SIZE)
 287                 map_page(v, 0, 0); /* XXX gross */
 288 #endif
 289
 290 #ifdef CONFIG_HIGHMEM
 291         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 292         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 293
 294         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
 295         kmap_prot = PAGE_KERNEL;
 296 #endif /* CONFIG_HIGHMEM */
 297
 298         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%lx\n",
 299                (unsigned long long)top_of_ram, total_ram);
 300         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 301                (long int)((top_of_ram - total_ram) >> 20));
 302         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 303 #ifdef CONFIG_HIGHMEM
 304         max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;
 305         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 306 #else
 307         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 308 #endif
 309         free_area_init_nodes(max_zone_pfns);
 310
 311         mark_nonram_nosave();
 312 }
 313 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 314
 315 void __init mem_init(void)
 316 {
 317 #ifdef CONFIG_NEED_MULTIPLE_NODES
 318         int nid;
 319 #endif
 320         pg_data_t *pgdat;
 321         unsigned long i;
 322         struct page *page;
 323         unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
 324
 325 #ifdef CONFIG_SWIOTLB
 326         if (ppc_swiotlb_enable)
 327                 swiotlb_init(1);
 328 #endif
 329
 330         num_physpages = lmb.memory.size >> PAGE_SHIFT;
 331         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 332
 333 #ifdef CONFIG_NEED_MULTIPLE_NODES
 334         for_each_online_node(nid) {
 335                 if (NODE_DATA(nid)->node_spanned_pages != 0) {
 336                         printk("freeing bootmem node %d\n", nid);
 337                         totalram_pages +=
 338                                 free_all_bootmem_node(NODE_DATA(nid));
 339                 }
 340         }
 341 #else
 342         max_mapnr = max_pfn;
 343         totalram_pages += free_all_bootmem();
 344 #endif
 345         for_each_online_pgdat(pgdat) {
 346                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 347                         if (!pfn_valid(pgdat->node_start_pfn + i))
 348                                 continue;
 349                         page = pgdat_page_nr(pgdat, i);
 350                         if (PageReserved(page))
 351                                 reservedpages++;
 352                 }
 353         }
 354
 355         codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 356         datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 357         initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 358         bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
 359
 360 #ifdef CONFIG_HIGHMEM
 361         {
 362                 unsigned long pfn, highmem_mapnr;
 363
 364                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
 365                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 366                         struct page *page = pfn_to_page(pfn);
 367                         if (lmb_is_reserved(pfn << PAGE_SHIFT))
 368                                 continue;
 369                         ClearPageReserved(page);
 370                         init_page_count(page);
 371                         __free_page(page);
 372                         totalhigh_pages++;
 373                         reservedpages--;
 374                 }
 375                 totalram_pages += totalhigh_pages;
 376                 printk(KERN_DEBUG "High memory: %luk\n",
 377                        totalhigh_pages << (PAGE_SHIFT-10));
 378         }
 379 #endif /* CONFIG_HIGHMEM */
 380
 381         printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 382                "%luk reserved, %luk data, %luk bss, %luk init)\n",
 383                 nr_free_pages() << (PAGE_SHIFT-10),
 384                 num_physpages << (PAGE_SHIFT-10),
 385                 codesize >> 10,
 386                 reservedpages << (PAGE_SHIFT-10),
 387                 datasize >> 10,
 388                 bsssize >> 10,
 389                 initsize >> 10);
 390
 391 #ifdef CONFIG_PPC32
 392         pr_info("Kernel virtual memory layout:\n");
 393         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 394 #ifdef CONFIG_HIGHMEM
 395         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 396                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 397 #endif /* CONFIG_HIGHMEM */
 398 #ifdef CONFIG_NOT_COHERENT_CACHE
 399         pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
 400                 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
 401 #endif /* CONFIG_NOT_COHERENT_CACHE */
 402         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 403                 ioremap_bot, IOREMAP_TOP);
 404         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 405                 VMALLOC_START, VMALLOC_END);
 406 #endif /* CONFIG_PPC32 */
 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_HUGETLB_PAGE
 429         if (PageCompound(page)) {
 430                 flush_dcache_icache_hugepage(page);
 431                 return;
 432         }
 433 #endif
 434 #ifdef CONFIG_BOOKE
 435         {
 436                 void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 437                 __flush_dcache_icache(start);
 438                 kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 439         }
 440 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 441         /* On 8xx there is no need to kmap since highmem is not supported */
 442         __flush_dcache_icache(page_address(page));
 443 #else
 444         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 445 #endif
 446 }
 447
 448 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 449 {
 450         clear_page(page);
 451
 452         /*
 453          * We shouldnt have to do this, but some versions of glibc
 454          * require it (ld.so assumes zero filled pages are icache clean)
 455          * - Anton
 456          */
 457         flush_dcache_page(pg);
 458 }
 459 EXPORT_SYMBOL(clear_user_page);
 460
 461 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 462                     struct page *pg)
 463 {
 464         copy_page(vto, vfrom);
 465
 466         /*
 467          * We should be able to use the following optimisation, however
 468          * there are two problems.
 469          * Firstly a bug in some versions of binutils meant PLT sections
 470          * were not marked executable.
 471          * Secondly the first word in the GOT section is blrl, used
 472          * to establish the GOT address. Until recently the GOT was
 473          * not marked executable.
 474          * - Anton
 475          */
 476 #if 0
 477         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 478                 return;
 479 #endif
 480
 481         flush_dcache_page(pg);
 482 }
 483
 484 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 485                              unsigned long addr, int len)
 486 {
 487         unsigned long maddr;
 488
 489         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 490         flush_icache_range(maddr, maddr + len);
 491         kunmap(page);
 492 }
 493 EXPORT_SYMBOL(flush_icache_user_range);
 494
 495 /*
 496  * This is called at the end of handling a user page fault, when the
 497  * fault has been handled by updating a PTE in the linux page tables.
 498  * We use it to preload an HPTE into the hash table corresponding to
 499  * the updated linux PTE.
 500  *
 501  * This must always be called with the pte lock held.
 502  */
 503 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 504                       pte_t *ptep)
 505 {
 506 #ifdef CONFIG_PPC_STD_MMU
 507         unsigned long access = 0, trap;
 508
 509         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 510         if (!pte_young(*ptep) || address >= TASK_SIZE)
 511                 return;
 512
 513         /* We try to figure out if we are coming from an instruction
 514          * access fault and pass that down to __hash_page so we avoid
 515          * double-faulting on execution of fresh text. We have to test
 516          * for regs NULL since init will get here first thing at boot
 517          *
 518          * We also avoid filling the hash if not coming from a fault
 519          */
 520         if (current->thread.regs == NULL)
 521                 return;
 522         trap = TRAP(current->thread.regs);
 523         if (trap == 0x400)
 524                 access |= _PAGE_EXEC;
 525         else if (trap != 0x300)
 526                 return;
 527         hash_preload(vma->vm_mm, address, access, trap);
 528 #endif /* CONFIG_PPC_STD_MMU */
 529 }