arch/powerpc/mm/init_64.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  *
   9  *  Derived from "arch/i386/mm/init.c"
  10  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  11  *
  12  *  Dave Engebretsen <engebret@us.ibm.com>
  13  *      Rework for PPC64 port.
  14  *
  15  *  This program is free software; you can redistribute it and/or
  16  *  modify it under the terms of the GNU General Public License
  17  *  as published by the Free Software Foundation; either version
  18  *  2 of the License, or (at your option) any later version.
  19  *
  20  */
  21
  22 #undef DEBUG
  23
  24 #include <linux/signal.h>
  25 #include <linux/sched.h>
  26 #include <linux/kernel.h>
  27 #include <linux/errno.h>
  28 #include <linux/string.h>
  29 #include <linux/types.h>
  30 #include <linux/mman.h>
  31 #include <linux/mm.h>
  32 #include <linux/swap.h>
  33 #include <linux/stddef.h>
  34 #include <linux/vmalloc.h>
  35 #include <linux/init.h>
  36 #include <linux/delay.h>
  37 #include <linux/bootmem.h>
  38 #include <linux/highmem.h>
  39 #include <linux/idr.h>
  40 #include <linux/nodemask.h>
  41 #include <linux/module.h>
  42 #include <linux/poison.h>
  43 #include <linux/lmb.h>
  44 #include <linux/hugetlb.h>
  45 #include <linux/slab.h>
  46
  47 #include <asm/pgalloc.h>
  48 #include <asm/page.h>
  49 #include <asm/prom.h>
  50 #include <asm/rtas.h>
  51 #include <asm/io.h>
  52 #include <asm/mmu_context.h>
  53 #include <asm/pgtable.h>
  54 #include <asm/mmu.h>
  55 #include <asm/uaccess.h>
  56 #include <asm/smp.h>
  57 #include <asm/machdep.h>
  58 #include <asm/tlb.h>
  59 #include <asm/eeh.h>
  60 #include <asm/processor.h>
  61 #include <asm/mmzone.h>
  62 #include <asm/cputable.h>
  63 #include <asm/sections.h>
  64 #include <asm/system.h>
  65 #include <asm/iommu.h>
  66 #include <asm/abs_addr.h>
  67 #include <asm/vdso.h>
  68
  69 #include "mmu_decl.h"
  70
  71 #ifdef CONFIG_PPC_STD_MMU_64
  72 #if PGTABLE_RANGE > USER_VSID_RANGE
  73 #warning Limited user VSID range means pagetable space is wasted
  74 #endif
  75
  76 #if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE)
  77 #warning TASK_SIZE is smaller than it needs to be.
  78 #endif
  79 #endif /* CONFIG_PPC_STD_MMU_64 */
  80
  81 phys_addr_t memstart_addr = ~0;
  82 phys_addr_t kernstart_addr;
  83
  84 void free_initmem(void)
  85 {
  86         unsigned long addr;
  87
  88         addr = (unsigned long)__init_begin;
  89         for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) {
  90                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
  91                 ClearPageReserved(virt_to_page(addr));
  92                 init_page_count(virt_to_page(addr));
  93                 free_page(addr);
  94                 totalram_pages++;
  95         }
  96         printk ("Freeing unused kernel memory: %luk freed\n",
  97                 ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10);
  98 }
  99
 100 #ifdef CONFIG_BLK_DEV_INITRD
 101 void free_initrd_mem(unsigned long start, unsigned long end)
 102 {
 103         if (start < end)
 104                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 105         for (; start < end; start += PAGE_SIZE) {
 106                 ClearPageReserved(virt_to_page(start));
 107                 init_page_count(virt_to_page(start));
 108                 free_page(start);
 109                 totalram_pages++;
 110         }
 111 }
 112 #endif
 113
 114 static void pgd_ctor(void *addr)
 115 {
 116         memset(addr, 0, PGD_TABLE_SIZE);
 117 }
 118
 119 static void pmd_ctor(void *addr)
 120 {
 121         memset(addr, 0, PMD_TABLE_SIZE);
 122 }
 123
 124 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
 125
 126 /*
 127  * Create a kmem_cache() for pagetables.  This is not used for PTE
 128  * pages - they're linked to struct page, come from the normal free
 129  * pages pool and have a different entry size (see real_pte_t) to
 130  * everything else.  Caches created by this function are used for all
 131  * the higher level pagetables, and for hugepage pagetables.
 132  */
 133 void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
 134 {
 135         char *name;
 136         unsigned long table_size = sizeof(void *) << shift;
 137         unsigned long align = table_size;
 138
 139         /* When batching pgtable pointers for RCU freeing, we store
 140          * the index size in the low bits.  Table alignment must be
 141          * big enough to fit it.
 142          *
 143          * Likewise, hugeapge pagetable pointers contain a (different)
 144          * shift value in the low bits.  All tables must be aligned so
 145          * as to leave enough 0 bits in the address to contain it. */
 146         unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
 147                                      HUGEPD_SHIFT_MASK + 1);
 148         struct kmem_cache *new;
 149
 150         /* It would be nice if this was a BUILD_BUG_ON(), but at the
 151          * moment, gcc doesn't seem to recognize is_power_of_2 as a
 152          * constant expression, so so much for that. */
 153         BUG_ON(!is_power_of_2(minalign));
 154         BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE));
 155
 156         if (PGT_CACHE(shift))
 157                 return; /* Already have a cache of this size */
 158
 159         align = max_t(unsigned long, align, minalign);
 160         name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
 161         new = kmem_cache_create(name, table_size, align, 0, ctor);
 162         PGT_CACHE(shift) = new;
 163
 164         pr_debug("Allocated pgtable cache for order %d\n", shift);
 165 }
 166
 167
 168 void pgtable_cache_init(void)
 169 {
 170         pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
 171         pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor);
 172         if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE))
 173                 panic("Couldn't allocate pgtable caches");
 174
 175         /* In all current configs, when the PUD index exists it's the
 176          * same size as either the pgd or pmd index.  Verify that the
 177          * initialization above has also created a PUD cache.  This
 178          * will need re-examiniation if we add new possibilities for
 179          * the pagetable layout. */
 180         BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE));
 181 }
 182
 183 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 184 /*
 185  * Given an address within the vmemmap, determine the pfn of the page that
 186  * represents the start of the section it is within.  Note that we have to
 187  * do this by hand as the proffered address may not be correctly aligned.
 188  * Subtraction of non-aligned pointers produces undefined results.
 189  */
 190 static unsigned long __meminit vmemmap_section_start(unsigned long page)
 191 {
 192         unsigned long offset = page - ((unsigned long)(vmemmap));
 193
 194         /* Return the pfn of the start of the section. */
 195         return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
 196 }
 197
 198 /*
 199  * Check if this vmemmap page is already initialised.  If any section
 200  * which overlaps this vmemmap page is initialised then this page is
 201  * initialised already.
 202  */
 203 static int __meminit vmemmap_populated(unsigned long start, int page_size)
 204 {
 205         unsigned long end = start + page_size;
 206
 207         for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
 208                 if (pfn_valid(vmemmap_section_start(start)))
 209                         return 1;
 210
 211         return 0;
 212 }
 213
 214 /* On hash-based CPUs, the vmemmap is bolted in the hash table.
 215  *
 216  * On Book3E CPUs, the vmemmap is currently mapped in the top half of
 217  * the vmalloc space using normal page tables, though the size of
 218  * pages encoded in the PTEs can be different
 219  */
 220
 221 #ifdef CONFIG_PPC_BOOK3E
 222 static void __meminit vmemmap_create_mapping(unsigned long start,
 223                                              unsigned long page_size,
 224                                              unsigned long phys)
 225 {
 226         /* Create a PTE encoding without page size */
 227         unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
 228                 _PAGE_KERNEL_RW;
 229
 230         /* PTEs only contain page size encodings up to 32M */
 231         BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
 232
 233         /* Encode the size in the PTE */
 234         flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
 235
 236         /* For each PTE for that area, map things. Note that we don't
 237          * increment phys because all PTEs are of the large size and
 238          * thus must have the low bits clear
 239          */
 240         for (i = 0; i < page_size; i += PAGE_SIZE)
 241                 BUG_ON(map_kernel_page(start + i, phys, flags));
 242 }
 243 #else /* CONFIG_PPC_BOOK3E */
 244 static void __meminit vmemmap_create_mapping(unsigned long start,
 245                                              unsigned long page_size,
 246                                              unsigned long phys)
 247 {
 248         int  mapped = htab_bolt_mapping(start, start + page_size, phys,
 249                                         PAGE_KERNEL, mmu_vmemmap_psize,
 250                                         mmu_kernel_ssize);
 251         BUG_ON(mapped < 0);
 252 }
 253 #endif /* CONFIG_PPC_BOOK3E */
 254
 255 int __meminit vmemmap_populate(struct page *start_page,
 256                                unsigned long nr_pages, int node)
 257 {
 258         unsigned long start = (unsigned long)start_page;
 259         unsigned long end = (unsigned long)(start_page + nr_pages);
 260         unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
 261
 262         /* Align to the page size of the linear mapping. */
 263         start = _ALIGN_DOWN(start, page_size);
 264
 265         pr_debug("vmemmap_populate page %p, %ld pages, node %d\n",
 266                  start_page, nr_pages, node);
 267         pr_debug(" -> map %lx..%lx\n", start, end);
 268
 269         for (; start < end; start += page_size) {
 270                 void *p;
 271
 272                 if (vmemmap_populated(start, page_size))
 273                         continue;
 274
 275                 p = vmemmap_alloc_block(page_size, node);
 276                 if (!p)
 277                         return -ENOMEM;
 278
 279                 pr_debug("      * %016lx..%016lx allocated at %p\n",
 280                          start, start + page_size, p);
 281
 282                 vmemmap_create_mapping(start, page_size, __pa(p));
 283         }
 284
 285         return 0;
 286 }
 287 #endif /* CONFIG_SPARSEMEM_VMEMMAP */