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/memblock.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/iommu.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 EXPORT_SYMBOL_GPL(memstart_addr);
  81 phys_addr_t kernstart_addr;
  82 EXPORT_SYMBOL_GPL(kernstart_addr);
  83
  84 static void pgd_ctor(void *addr)
  85 {
  86         memset(addr, 0, PGD_TABLE_SIZE);
  87 }
  88
  89 static void pmd_ctor(void *addr)
  90 {
  91         memset(addr, 0, PMD_TABLE_SIZE);
  92 }
  93
  94 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
  95
  96 /*
  97  * Create a kmem_cache() for pagetables.  This is not used for PTE
  98  * pages - they're linked to struct page, come from the normal free
  99  * pages pool and have a different entry size (see real_pte_t) to
 100  * everything else.  Caches created by this function are used for all
 101  * the higher level pagetables, and for hugepage pagetables.
 102  */
 103 void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
 104 {
 105         char *name;
 106         unsigned long table_size = sizeof(void *) << shift;
 107         unsigned long align = table_size;
 108
 109         /* When batching pgtable pointers for RCU freeing, we store
 110          * the index size in the low bits.  Table alignment must be
 111          * big enough to fit it.
 112          *
 113          * Likewise, hugeapge pagetable pointers contain a (different)
 114          * shift value in the low bits.  All tables must be aligned so
 115          * as to leave enough 0 bits in the address to contain it. */
 116         unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
 117                                      HUGEPD_SHIFT_MASK + 1);
 118         struct kmem_cache *new;
 119
 120         /* It would be nice if this was a BUILD_BUG_ON(), but at the
 121          * moment, gcc doesn't seem to recognize is_power_of_2 as a
 122          * constant expression, so so much for that. */
 123         BUG_ON(!is_power_of_2(minalign));
 124         BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE));
 125
 126         if (PGT_CACHE(shift))
 127                 return; /* Already have a cache of this size */
 128
 129         align = max_t(unsigned long, align, minalign);
 130         name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
 131         new = kmem_cache_create(name, table_size, align, 0, ctor);
 132         PGT_CACHE(shift) = new;
 133
 134         pr_debug("Allocated pgtable cache for order %d\n", shift);
 135 }
 136
 137
 138 void pgtable_cache_init(void)
 139 {
 140         pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
 141         pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor);
 142         if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE))
 143                 panic("Couldn't allocate pgtable caches");
 144
 145         /* In all current configs, when the PUD index exists it's the
 146          * same size as either the pgd or pmd index.  Verify that the
 147          * initialization above has also created a PUD cache.  This
 148          * will need re-examiniation if we add new possibilities for
 149          * the pagetable layout. */
 150         BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE));
 151 }
 152
 153 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 154 /*
 155  * Given an address within the vmemmap, determine the pfn of the page that
 156  * represents the start of the section it is within.  Note that we have to
 157  * do this by hand as the proffered address may not be correctly aligned.
 158  * Subtraction of non-aligned pointers produces undefined results.
 159  */
 160 static unsigned long __meminit vmemmap_section_start(unsigned long page)
 161 {
 162         unsigned long offset = page - ((unsigned long)(vmemmap));
 163
 164         /* Return the pfn of the start of the section. */
 165         return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
 166 }
 167
 168 /*
 169  * Check if this vmemmap page is already initialised.  If any section
 170  * which overlaps this vmemmap page is initialised then this page is
 171  * initialised already.
 172  */
 173 static int __meminit vmemmap_populated(unsigned long start, int page_size)
 174 {
 175         unsigned long end = start + page_size;
 176
 177         for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
 178                 if (pfn_valid(vmemmap_section_start(start)))
 179                         return 1;
 180
 181         return 0;
 182 }
 183
 184 /* On hash-based CPUs, the vmemmap is bolted in the hash table.
 185  *
 186  * On Book3E CPUs, the vmemmap is currently mapped in the top half of
 187  * the vmalloc space using normal page tables, though the size of
 188  * pages encoded in the PTEs can be different
 189  */
 190
 191 #ifdef CONFIG_PPC_BOOK3E
 192 static void __meminit vmemmap_create_mapping(unsigned long start,
 193                                              unsigned long page_size,
 194                                              unsigned long phys)
 195 {
 196         /* Create a PTE encoding without page size */
 197         unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED |
 198                 _PAGE_KERNEL_RW;
 199
 200         /* PTEs only contain page size encodings up to 32M */
 201         BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
 202
 203         /* Encode the size in the PTE */
 204         flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
 205
 206         /* For each PTE for that area, map things. Note that we don't
 207          * increment phys because all PTEs are of the large size and
 208          * thus must have the low bits clear
 209          */
 210         for (i = 0; i < page_size; i += PAGE_SIZE)
 211                 BUG_ON(map_kernel_page(start + i, phys, flags));
 212 }
 213 #else /* CONFIG_PPC_BOOK3E */
 214 static void __meminit vmemmap_create_mapping(unsigned long start,
 215                                              unsigned long page_size,
 216                                              unsigned long phys)
 217 {
 218         int  mapped = htab_bolt_mapping(start, start + page_size, phys,
 219                                         PAGE_KERNEL, mmu_vmemmap_psize,
 220                                         mmu_kernel_ssize);
 221         BUG_ON(mapped < 0);
 222 }
 223 #endif /* CONFIG_PPC_BOOK3E */
 224
 225 struct vmemmap_backing *vmemmap_list;
 226
 227 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node)
 228 {
 229         static struct vmemmap_backing *next;
 230         static int num_left;
 231
 232         /* allocate a page when required and hand out chunks */
 233         if (!next || !num_left) {
 234                 next = vmemmap_alloc_block(PAGE_SIZE, node);
 235                 if (unlikely(!next)) {
 236                         WARN_ON(1);
 237                         return NULL;
 238                 }
 239                 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing);
 240         }
 241
 242         num_left--;
 243
 244         return next++;
 245 }
 246
 247 static __meminit void vmemmap_list_populate(unsigned long phys,
 248                                             unsigned long start,
 249                                             int node)
 250 {
 251         struct vmemmap_backing *vmem_back;
 252
 253         vmem_back = vmemmap_list_alloc(node);
 254         if (unlikely(!vmem_back)) {
 255                 WARN_ON(1);
 256                 return;
 257         }
 258
 259         vmem_back->phys = phys;
 260         vmem_back->virt_addr = start;
 261         vmem_back->list = vmemmap_list;
 262
 263         vmemmap_list = vmem_back;
 264 }
 265
 266 int __meminit vmemmap_populate(struct page *start_page,
 267                                unsigned long nr_pages, int node)
 268 {
 269         unsigned long start = (unsigned long)start_page;
 270         unsigned long end = (unsigned long)(start_page + nr_pages);
 271         unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
 272
 273         /* Align to the page size of the linear mapping. */
 274         start = _ALIGN_DOWN(start, page_size);
 275
 276         pr_debug("vmemmap_populate page %p, %ld pages, node %d\n",
 277                  start_page, nr_pages, node);
 278         pr_debug(" -> map %lx..%lx\n", start, end);
 279
 280         for (; start < end; start += page_size) {
 281                 void *p;
 282
 283                 if (vmemmap_populated(start, page_size))
 284                         continue;
 285
 286                 p = vmemmap_alloc_block(page_size, node);
 287                 if (!p)
 288                         return -ENOMEM;
 289
 290                 vmemmap_list_populate(__pa(p), start, node);
 291
 292                 pr_debug("      * %016lx..%016lx allocated at %p\n",
 293                          start, start + page_size, p);
 294
 295                 vmemmap_create_mapping(start, page_size, __pa(p));
 296         }
 297
 298         return 0;
 299 }
 300 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 301