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
  45 #include <asm/pgalloc.h>
  46 #include <asm/page.h>
  47 #include <asm/prom.h>
  48 #include <asm/rtas.h>
  49 #include <asm/io.h>
  50 #include <asm/mmu_context.h>
  51 #include <asm/pgtable.h>
  52 #include <asm/mmu.h>
  53 #include <asm/uaccess.h>
  54 #include <asm/smp.h>
  55 #include <asm/machdep.h>
  56 #include <asm/tlb.h>
  57 #include <asm/eeh.h>
  58 #include <asm/processor.h>
  59 #include <asm/mmzone.h>
  60 #include <asm/cputable.h>
  61 #include <asm/sections.h>
  62 #include <asm/system.h>
  63 #include <asm/iommu.h>
  64 #include <asm/abs_addr.h>
  65 #include <asm/vdso.h>
  66
  67 #include "mmu_decl.h"
  68
  69 #ifdef CONFIG_PPC_STD_MMU_64
  70 #if PGTABLE_RANGE > USER_VSID_RANGE
  71 #warning Limited user VSID range means pagetable space is wasted
  72 #endif
  73
  74 #if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE)
  75 #warning TASK_SIZE is smaller than it needs to be.
  76 #endif
  77 #endif /* CONFIG_PPC_STD_MMU_64 */
  78
  79 phys_addr_t memstart_addr = ~0;
  80 phys_addr_t kernstart_addr;
  81
  82 void free_initmem(void)
  83 {
  84         unsigned long addr;
  85
  86         addr = (unsigned long)__init_begin;
  87         for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) {
  88                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
  89                 ClearPageReserved(virt_to_page(addr));
  90                 init_page_count(virt_to_page(addr));
  91                 free_page(addr);
  92                 totalram_pages++;
  93         }
  94         printk ("Freeing unused kernel memory: %luk freed\n",
  95                 ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10);
  96 }
  97
  98 #ifdef CONFIG_BLK_DEV_INITRD
  99 void free_initrd_mem(unsigned long start, unsigned long end)
 100 {
 101         if (start < end)
 102                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 103         for (; start < end; start += PAGE_SIZE) {
 104                 ClearPageReserved(virt_to_page(start));
 105                 init_page_count(virt_to_page(start));
 106                 free_page(start);
 107                 totalram_pages++;
 108         }
 109 }
 110 #endif
 111
 112 static void pgd_ctor(void *addr)
 113 {
 114         memset(addr, 0, PGD_TABLE_SIZE);
 115 }
 116
 117 static void pmd_ctor(void *addr)
 118 {
 119         memset(addr, 0, PMD_TABLE_SIZE);
 120 }
 121
 122 static const unsigned int pgtable_cache_size[2] = {
 123         PGD_TABLE_SIZE, PMD_TABLE_SIZE
 124 };
 125 static const char *pgtable_cache_name[ARRAY_SIZE(pgtable_cache_size)] = {
 126 #ifdef CONFIG_PPC_64K_PAGES
 127         "pgd_cache", "pmd_cache",
 128 #else
 129         "pgd_cache", "pud_pmd_cache",
 130 #endif /* CONFIG_PPC_64K_PAGES */
 131 };
 132
 133 #ifdef CONFIG_HUGETLB_PAGE
 134 /* Hugepages need an extra cache per hugepagesize, initialized in
 135  * hugetlbpage.c.  We can't put into the tables above, because HPAGE_SHIFT
 136  * is not compile time constant. */
 137 struct kmem_cache *pgtable_cache[ARRAY_SIZE(pgtable_cache_size)+MMU_PAGE_COUNT];
 138 #else
 139 struct kmem_cache *pgtable_cache[ARRAY_SIZE(pgtable_cache_size)];
 140 #endif
 141
 142 void pgtable_cache_init(void)
 143 {
 144         pgtable_cache[0] = kmem_cache_create(pgtable_cache_name[0], PGD_TABLE_SIZE, PGD_TABLE_SIZE, SLAB_PANIC, pgd_ctor);
 145         pgtable_cache[1] = kmem_cache_create(pgtable_cache_name[1], PMD_TABLE_SIZE, PMD_TABLE_SIZE, SLAB_PANIC, pmd_ctor);
 146 }
 147
 148 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 149 /*
 150  * Given an address within the vmemmap, determine the pfn of the page that
 151  * represents the start of the section it is within.  Note that we have to
 152  * do this by hand as the proffered address may not be correctly aligned.
 153  * Subtraction of non-aligned pointers produces undefined results.
 154  */
 155 static unsigned long __meminit vmemmap_section_start(unsigned long page)
 156 {
 157         unsigned long offset = page - ((unsigned long)(vmemmap));
 158
 159         /* Return the pfn of the start of the section. */
 160         return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
 161 }
 162
 163 /*
 164  * Check if this vmemmap page is already initialised.  If any section
 165  * which overlaps this vmemmap page is initialised then this page is
 166  * initialised already.
 167  */
 168 static int __meminit vmemmap_populated(unsigned long start, int page_size)
 169 {
 170         unsigned long end = start + page_size;
 171
 172         for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
 173                 if (pfn_valid(vmemmap_section_start(start)))
 174                         return 1;
 175
 176         return 0;
 177 }
 178
 179 /* On hash-based CPUs, the vmemmap is bolted in the hash table.
 180  *
 181  * On Book3E CPUs, the vmemmap is currently mapped in the top half of
 182  * the vmalloc space using normal page tables, though the size of
 183  * pages encoded in the PTEs can be different
 184  */
 185
 186 #ifdef CONFIG_PPC_BOOK3E
 187 static void __meminit vmemmap_create_mapping(unsigned long start,
 188                                              unsigned long page_size,
 189                                              unsigned long phys)
 190 {
 191         /* Create a PTE encoding without page size */
 192         unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
 193                 _PAGE_KERNEL_RW;
 194
 195         /* PTEs only contain page size encodings up to 32M */
 196         BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
 197
 198         /* Encode the size in the PTE */
 199         flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
 200
 201         /* For each PTE for that area, map things. Note that we don't
 202          * increment phys because all PTEs are of the large size and
 203          * thus must have the low bits clear
 204          */
 205         for (i = 0; i < page_size; i += PAGE_SIZE)
 206                 BUG_ON(map_kernel_page(start + i, phys, flags));
 207 }
 208 #else /* CONFIG_PPC_BOOK3E */
 209 static void __meminit vmemmap_create_mapping(unsigned long start,
 210                                              unsigned long page_size,
 211                                              unsigned long phys)
 212 {
 213         int  mapped = htab_bolt_mapping(start, start + page_size, phys,
 214                                         PAGE_KERNEL, mmu_vmemmap_psize,
 215                                         mmu_kernel_ssize);
 216         BUG_ON(mapped < 0);
 217 }
 218 #endif /* CONFIG_PPC_BOOK3E */
 219
 220 int __meminit vmemmap_populate(struct page *start_page,
 221                                unsigned long nr_pages, int node)
 222 {
 223         unsigned long start = (unsigned long)start_page;
 224         unsigned long end = (unsigned long)(start_page + nr_pages);
 225         unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
 226
 227         /* Align to the page size of the linear mapping. */
 228         start = _ALIGN_DOWN(start, page_size);
 229
 230         pr_debug("vmemmap_populate page %p, %ld pages, node %d\n",
 231                  start_page, nr_pages, node);
 232         pr_debug(" -> map %lx..%lx\n", start, end);
 233
 234         for (; start < end; start += page_size) {
 235                 void *p;
 236
 237                 if (vmemmap_populated(start, page_size))
 238                         continue;
 239
 240                 p = vmemmap_alloc_block(page_size, node);
 241                 if (!p)
 242                         return -ENOMEM;
 243
 244                 pr_debug("      * %016lx..%016lx allocated at %p\n",
 245                          start, start + page_size, p);
 246
 247                 vmemmap_create_mapping(start, page_size, __pa(p));
 248         }
 249
 250         return 0;
 251 }
 252 #endif /* CONFIG_SPARSEMEM_VMEMMAP */