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/export.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/memblock.h>
  36 #include <linux/hugetlb.h>
  37 #include <linux/slab.h>
  38
  39 #include <asm/pgalloc.h>
  40 #include <asm/prom.h>
  41 #include <asm/io.h>
  42 #include <asm/mmu_context.h>
  43 #include <asm/pgtable.h>
  44 #include <asm/mmu.h>
  45 #include <asm/smp.h>
  46 #include <asm/machdep.h>
  47 #include <asm/btext.h>
  48 #include <asm/tlb.h>
  49 #include <asm/sections.h>
  50 #include <asm/sparsemem.h>
  51 #include <asm/vdso.h>
  52 #include <asm/fixmap.h>
  53 #include <asm/swiotlb.h>
  54 #include <asm/rtas.h>
  55
  56 #include "mmu_decl.h"
  57
  58 #ifndef CPU_FTR_COHERENT_ICACHE
  59 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  60 #define CPU_FTR_NOEXECUTE       0
  61 #endif
  62
  63 int init_bootmem_done;
  64 int mem_init_done;
  65 unsigned long long memory_limit;
  66
  67 #ifdef CONFIG_HIGHMEM
  68 pte_t *kmap_pte;
  69 EXPORT_SYMBOL(kmap_pte);
  70 pgprot_t kmap_prot;
  71 EXPORT_SYMBOL(kmap_prot);
  72
  73 static inline pte_t *virt_to_kpte(unsigned long vaddr)
  74 {
  75         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
  76                         vaddr), vaddr), vaddr);
  77 }
  78 #endif
  79
  80 int page_is_ram(unsigned long pfn)
  81 {
  82 #ifndef CONFIG_PPC64    /* XXX for now */
  83         return pfn < max_pfn;
  84 #else
  85         unsigned long paddr = (pfn << PAGE_SHIFT);
  86         struct memblock_region *reg;
  87
  88         for_each_memblock(memory, reg)
  89                 if (paddr >= reg->base && paddr < (reg->base + reg->size))
  90                         return 1;
  91         return 0;
  92 #endif
  93 }
  94
  95 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  96                               unsigned long size, pgprot_t vma_prot)
  97 {
  98         if (ppc_md.phys_mem_access_prot)
  99                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
 100
 101         if (!page_is_ram(pfn))
 102                 vma_prot = pgprot_noncached(vma_prot);
 103
 104         return vma_prot;
 105 }
 106 EXPORT_SYMBOL(phys_mem_access_prot);
 107
 108 #ifdef CONFIG_MEMORY_HOTPLUG
 109
 110 #ifdef CONFIG_NUMA
 111 int memory_add_physaddr_to_nid(u64 start)
 112 {
 113         return hot_add_scn_to_nid(start);
 114 }
 115 #endif
 116
 117 int arch_add_memory(int nid, u64 start, u64 size)
 118 {
 119         struct pglist_data *pgdata;
 120         struct zone *zone;
 121         unsigned long start_pfn = start >> PAGE_SHIFT;
 122         unsigned long nr_pages = size >> PAGE_SHIFT;
 123
 124         pgdata = NODE_DATA(nid);
 125
 126         start = (unsigned long)__va(start);
 127         if (create_section_mapping(start, start + size))
 128                 return -EINVAL;
 129
 130         /* this should work for most non-highmem platforms */
 131         zone = pgdata->node_zones;
 132
 133         return __add_pages(nid, zone, start_pfn, nr_pages);
 134 }
 135
 136 #ifdef CONFIG_MEMORY_HOTREMOVE
 137 int arch_remove_memory(u64 start, u64 size)
 138 {
 139         unsigned long start_pfn = start >> PAGE_SHIFT;
 140         unsigned long nr_pages = size >> PAGE_SHIFT;
 141         struct zone *zone;
 142
 143         zone = page_zone(pfn_to_page(start_pfn));
 144         return __remove_pages(zone, start_pfn, nr_pages);
 145 }
 146 #endif
 147 #endif /* CONFIG_MEMORY_HOTPLUG */
 148
 149 /*
 150  * walk_memory_resource() needs to make sure there is no holes in a given
 151  * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
 152  * Instead it maintains it in memblock.memory structures.  Walk through the
 153  * memory regions, find holes and callback for contiguous regions.
 154  */
 155 int
 156 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 157                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 158 {
 159         struct memblock_region *reg;
 160         unsigned long end_pfn = start_pfn + nr_pages;
 161         unsigned long tstart, tend;
 162         int ret = -1;
 163
 164         for_each_memblock(memory, reg) {
 165                 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
 166                 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
 167                 if (tstart >= tend)
 168                         continue;
 169                 ret = (*func)(tstart, tend - tstart, arg);
 170                 if (ret)
 171                         break;
 172         }
 173         return ret;
 174 }
 175 EXPORT_SYMBOL_GPL(walk_system_ram_range);
 176
 177 /*
 178  * Initialize the bootmem system and give it all the memory we
 179  * have available.  If we are using highmem, we only put the
 180  * lowmem into the bootmem system.
 181  */
 182 #ifndef CONFIG_NEED_MULTIPLE_NODES
 183 void __init do_init_bootmem(void)
 184 {
 185         unsigned long start, bootmap_pages;
 186         unsigned long total_pages;
 187         struct memblock_region *reg;
 188         int boot_mapsize;
 189
 190         max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
 191         total_pages = (memblock_end_of_DRAM() - memstart_addr) >> PAGE_SHIFT;
 192 #ifdef CONFIG_HIGHMEM
 193         total_pages = total_lowmem >> PAGE_SHIFT;
 194         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
 195 #endif
 196
 197         /*
 198          * Find an area to use for the bootmem bitmap.  Calculate the size of
 199          * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 200          * Add 1 additional page in case the address isn't page-aligned.
 201          */
 202         bootmap_pages = bootmem_bootmap_pages(total_pages);
 203
 204         start = memblock_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
 205
 206         min_low_pfn = MEMORY_START >> PAGE_SHIFT;
 207         boot_mapsize = init_bootmem_node(NODE_DATA(0), start >> PAGE_SHIFT, min_low_pfn, max_low_pfn);
 208
 209         /* Place all memblock_regions in the same node and merge contiguous
 210          * memblock_regions
 211          */
 212         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
 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_each_memblock(reserved, reg) {
 222                 unsigned long top = reg->base + reg->size - 1;
 223                 if (top < lowmem_end_addr)
 224                         reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
 225                 else if (reg->base < lowmem_end_addr) {
 226                         unsigned long trunc_size = lowmem_end_addr - reg->base;
 227                         reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT);
 228                 }
 229         }
 230 #else
 231         free_bootmem_with_active_regions(0, max_pfn);
 232
 233         /* reserve the sections we're already using */
 234         for_each_memblock(reserved, reg)
 235                 reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
 236 #endif
 237         /* XXX need to clip this if using highmem? */
 238         sparse_memory_present_with_active_regions(0);
 239
 240         init_bootmem_done = 1;
 241 }
 242
 243 /* mark pages that don't exist as nosave */
 244 static int __init mark_nonram_nosave(void)
 245 {
 246         struct memblock_region *reg, *prev = NULL;
 247
 248         for_each_memblock(memory, reg) {
 249                 if (prev &&
 250                     memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
 251                         register_nosave_region(memblock_region_memory_end_pfn(prev),
 252                                                memblock_region_memory_base_pfn(reg));
 253                 prev = reg;
 254         }
 255         return 0;
 256 }
 257
 258 /*
 259  * paging_init() sets up the page tables - in fact we've already done this.
 260  */
 261 void __init paging_init(void)
 262 {
 263         unsigned long long total_ram = memblock_phys_mem_size();
 264         phys_addr_t top_of_ram = memblock_end_of_DRAM();
 265         unsigned long max_zone_pfns[MAX_NR_ZONES];
 266
 267 #ifdef CONFIG_PPC32
 268         unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
 269         unsigned long end = __fix_to_virt(FIX_HOLE);
 270
 271         for (; v < end; v += PAGE_SIZE)
 272                 map_page(v, 0, 0); /* XXX gross */
 273 #endif
 274
 275 #ifdef CONFIG_HIGHMEM
 276         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 277         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 278
 279         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
 280         kmap_prot = PAGE_KERNEL;
 281 #endif /* CONFIG_HIGHMEM */
 282
 283         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
 284                (unsigned long long)top_of_ram, total_ram);
 285         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 286                (long int)((top_of_ram - total_ram) >> 20));
 287         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 288 #ifdef CONFIG_HIGHMEM
 289         max_zone_pfns[ZONE_DMA] = lowmem_end_addr >> PAGE_SHIFT;
 290         max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 291 #else
 292         max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 293 #endif
 294         free_area_init_nodes(max_zone_pfns);
 295
 296         mark_nonram_nosave();
 297 }
 298 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 299
 300 static void __init register_page_bootmem_info(void)
 301 {
 302         int i;
 303
 304         for_each_online_node(i)
 305                 register_page_bootmem_info_node(NODE_DATA(i));
 306 }
 307
 308 void __init mem_init(void)
 309 {
 310         /*
 311          * book3s is limited to 16 page sizes due to encoding this in
 312          * a 4-bit field for slices.
 313          */
 314         BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
 315
 316 #ifdef CONFIG_SWIOTLB
 317         swiotlb_init(0);
 318 #endif
 319
 320         register_page_bootmem_info();
 321         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 322         set_max_mapnr(max_pfn);
 323         free_all_bootmem();
 324
 325 #ifdef CONFIG_HIGHMEM
 326         {
 327                 unsigned long pfn, highmem_mapnr;
 328
 329                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
 330                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 331                         phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
 332                         struct page *page = pfn_to_page(pfn);
 333                         if (!memblock_is_reserved(paddr))
 334                                 free_highmem_page(page);
 335                 }
 336         }
 337 #endif /* CONFIG_HIGHMEM */
 338
 339 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
 340         /*
 341          * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
 342          * functions.... do it here for the non-smp case.
 343          */
 344         per_cpu(next_tlbcam_idx, smp_processor_id()) =
 345                 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 346 #endif
 347
 348         mem_init_print_info(NULL);
 349 #ifdef CONFIG_PPC32
 350         pr_info("Kernel virtual memory layout:\n");
 351         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 352 #ifdef CONFIG_HIGHMEM
 353         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 354                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 355 #endif /* CONFIG_HIGHMEM */
 356 #ifdef CONFIG_NOT_COHERENT_CACHE
 357         pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
 358                 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
 359 #endif /* CONFIG_NOT_COHERENT_CACHE */
 360         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 361                 ioremap_bot, IOREMAP_TOP);
 362         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 363                 VMALLOC_START, VMALLOC_END);
 364 #endif /* CONFIG_PPC32 */
 365
 366         mem_init_done = 1;
 367 }
 368
 369 void free_initmem(void)
 370 {
 371         ppc_md.progress = ppc_printk_progress;
 372         free_initmem_default(POISON_FREE_INITMEM);
 373 }
 374
 375 #ifdef CONFIG_BLK_DEV_INITRD
 376 void __init free_initrd_mem(unsigned long start, unsigned long end)
 377 {
 378         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 379 }
 380 #endif
 381
 382 /*
 383  * This is called when a page has been modified by the kernel.
 384  * It just marks the page as not i-cache clean.  We do the i-cache
 385  * flush later when the page is given to a user process, if necessary.
 386  */
 387 void flush_dcache_page(struct page *page)
 388 {
 389         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 390                 return;
 391         /* avoid an atomic op if possible */
 392         if (test_bit(PG_arch_1, &page->flags))
 393                 clear_bit(PG_arch_1, &page->flags);
 394 }
 395 EXPORT_SYMBOL(flush_dcache_page);
 396
 397 void flush_dcache_icache_page(struct page *page)
 398 {
 399 #ifdef CONFIG_HUGETLB_PAGE
 400         if (PageCompound(page)) {
 401                 flush_dcache_icache_hugepage(page);
 402                 return;
 403         }
 404 #endif
 405 #ifdef CONFIG_BOOKE
 406         {
 407                 void *start = kmap_atomic(page);
 408                 __flush_dcache_icache(start);
 409                 kunmap_atomic(start);
 410         }
 411 #elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 412         /* On 8xx there is no need to kmap since highmem is not supported */
 413         __flush_dcache_icache(page_address(page));
 414 #else
 415         __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 416 #endif
 417 }
 418 EXPORT_SYMBOL(flush_dcache_icache_page);
 419
 420 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 421 {
 422         clear_page(page);
 423
 424         /*
 425          * We shouldn't have to do this, but some versions of glibc
 426          * require it (ld.so assumes zero filled pages are icache clean)
 427          * - Anton
 428          */
 429         flush_dcache_page(pg);
 430 }
 431 EXPORT_SYMBOL(clear_user_page);
 432
 433 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 434                     struct page *pg)
 435 {
 436         copy_page(vto, vfrom);
 437
 438         /*
 439          * We should be able to use the following optimisation, however
 440          * there are two problems.
 441          * Firstly a bug in some versions of binutils meant PLT sections
 442          * were not marked executable.
 443          * Secondly the first word in the GOT section is blrl, used
 444          * to establish the GOT address. Until recently the GOT was
 445          * not marked executable.
 446          * - Anton
 447          */
 448 #if 0
 449         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 450                 return;
 451 #endif
 452
 453         flush_dcache_page(pg);
 454 }
 455
 456 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 457                              unsigned long addr, int len)
 458 {
 459         unsigned long maddr;
 460
 461         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 462         flush_icache_range(maddr, maddr + len);
 463         kunmap(page);
 464 }
 465 EXPORT_SYMBOL(flush_icache_user_range);
 466
 467 /*
 468  * This is called at the end of handling a user page fault, when the
 469  * fault has been handled by updating a PTE in the linux page tables.
 470  * We use it to preload an HPTE into the hash table corresponding to
 471  * the updated linux PTE.
 472  *
 473  * This must always be called with the pte lock held.
 474  */
 475 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 476                       pte_t *ptep)
 477 {
 478 #ifdef CONFIG_PPC_STD_MMU
 479         /*
 480          * We don't need to worry about _PAGE_PRESENT here because we are
 481          * called with either mm->page_table_lock held or ptl lock held
 482          */
 483         unsigned long access = 0, trap;
 484
 485         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 486         if (!pte_young(*ptep) || address >= TASK_SIZE)
 487                 return;
 488
 489         /* We try to figure out if we are coming from an instruction
 490          * access fault and pass that down to __hash_page so we avoid
 491          * double-faulting on execution of fresh text. We have to test
 492          * for regs NULL since init will get here first thing at boot
 493          *
 494          * We also avoid filling the hash if not coming from a fault
 495          */
 496         if (current->thread.regs == NULL)
 497                 return;
 498         trap = TRAP(current->thread.regs);
 499         if (trap == 0x400)
 500                 access |= _PAGE_EXEC;
 501         else if (trap != 0x300)
 502                 return;
 503         hash_preload(vma->vm_mm, address, access, trap);
 504 #endif /* CONFIG_PPC_STD_MMU */
 505 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
 506         && defined(CONFIG_HUGETLB_PAGE)
 507         if (is_vm_hugetlb_page(vma))
 508                 book3e_hugetlb_preload(vma, address, *ptep);
 509 #endif
 510 }
 511
 512 /*
 513  * System memory should not be in /proc/iomem but various tools expect it
 514  * (eg kdump).
 515  */
 516 static int __init add_system_ram_resources(void)
 517 {
 518         struct memblock_region *reg;
 519
 520         for_each_memblock(memory, reg) {
 521                 struct resource *res;
 522                 unsigned long base = reg->base;
 523                 unsigned long size = reg->size;
 524
 525                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 526                 WARN_ON(!res);
 527
 528                 if (res) {
 529                         res->name = "System RAM";
 530                         res->start = base;
 531                         res->end = base + size - 1;
 532                         res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 533                         WARN_ON(request_resource(&iomem_resource, res) < 0);
 534                 }
 535         }
 536
 537         return 0;
 538 }
 539 subsys_initcall(add_system_ram_resources);
 540
 541 #ifdef CONFIG_STRICT_DEVMEM
 542 /*
 543  * devmem_is_allowed(): check to see if /dev/mem access to a certain address
 544  * is valid. The argument is a physical page number.
 545  *
 546  * Access has to be given to non-kernel-ram areas as well, these contain the
 547  * PCI mmio resources as well as potential bios/acpi data regions.
 548  */
 549 int devmem_is_allowed(unsigned long pfn)
 550 {
 551         if (iomem_is_exclusive(pfn << PAGE_SHIFT))
 552                 return 0;
 553         if (!page_is_ram(pfn))
 554                 return 1;
 555         if (page_is_rtas_user_buf(pfn))
 556                 return 1;
 557         return 0;
 558 }
 559 #endif /* CONFIG_STRICT_DEVMEM */