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/abs_addr.h> 66 #include <asm/vdso.h> 67 68 #include "mmu_decl.h" 69 70 #ifdef CONFIG_PPC_STD_MMU_64 71 #if PGTABLE_RANGE > USER_VSID_RANGE 72 #warning Limited user VSID range means pagetable space is wasted 73 #endif 74 75 #if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE) 76 #warning TASK_SIZE is smaller than it needs to be. 77 #endif 78 #endif /* CONFIG_PPC_STD_MMU_64 */ 79 80 phys_addr_t memstart_addr = ~0; 81 EXPORT_SYMBOL_GPL(memstart_addr); 82 phys_addr_t kernstart_addr; 83 EXPORT_SYMBOL_GPL(kernstart_addr); 84 85 static void pgd_ctor(void *addr) 86 { 87 memset(addr, 0, PGD_TABLE_SIZE); 88 } 89 90 static void pmd_ctor(void *addr) 91 { 92 memset(addr, 0, PMD_TABLE_SIZE); 93 } 94 95 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; 96 97 /* 98 * Create a kmem_cache() for pagetables. This is not used for PTE 99 * pages - they're linked to struct page, come from the normal free 100 * pages pool and have a different entry size (see real_pte_t) to 101 * everything else. Caches created by this function are used for all 102 * the higher level pagetables, and for hugepage pagetables. 103 */ 104 void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) 105 { 106 char *name; 107 unsigned long table_size = sizeof(void *) << shift; 108 unsigned long align = table_size; 109 110 /* When batching pgtable pointers for RCU freeing, we store 111 * the index size in the low bits. Table alignment must be 112 * big enough to fit it. 113 * 114 * Likewise, hugeapge pagetable pointers contain a (different) 115 * shift value in the low bits. All tables must be aligned so 116 * as to leave enough 0 bits in the address to contain it. */ 117 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, 118 HUGEPD_SHIFT_MASK + 1); 119 struct kmem_cache *new; 120 121 /* It would be nice if this was a BUILD_BUG_ON(), but at the 122 * moment, gcc doesn't seem to recognize is_power_of_2 as a 123 * constant expression, so so much for that. */ 124 BUG_ON(!is_power_of_2(minalign)); 125 BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); 126 127 if (PGT_CACHE(shift)) 128 return; /* Already have a cache of this size */ 129 130 align = max_t(unsigned long, align, minalign); 131 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); 132 new = kmem_cache_create(name, table_size, align, 0, ctor); 133 PGT_CACHE(shift) = new; 134 135 pr_debug("Allocated pgtable cache for order %d\n", shift); 136 } 137 138 139 void pgtable_cache_init(void) 140 { 141 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); 142 pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor); 143 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE)) 144 panic("Couldn't allocate pgtable caches"); 145 146 /* In all current configs, when the PUD index exists it's the 147 * same size as either the pgd or pmd index. Verify that the 148 * initialization above has also created a PUD cache. This 149 * will need re-examiniation if we add new possibilities for 150 * the pagetable layout. */ 151 BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); 152 } 153 154 #ifdef CONFIG_SPARSEMEM_VMEMMAP 155 /* 156 * Given an address within the vmemmap, determine the pfn of the page that 157 * represents the start of the section it is within. Note that we have to 158 * do this by hand as the proffered address may not be correctly aligned. 159 * Subtraction of non-aligned pointers produces undefined results. 160 */ 161 static unsigned long __meminit vmemmap_section_start(unsigned long page) 162 { 163 unsigned long offset = page - ((unsigned long)(vmemmap)); 164 165 /* Return the pfn of the start of the section. */ 166 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 167 } 168 169 /* 170 * Check if this vmemmap page is already initialised. If any section 171 * which overlaps this vmemmap page is initialised then this page is 172 * initialised already. 173 */ 174 static int __meminit vmemmap_populated(unsigned long start, int page_size) 175 { 176 unsigned long end = start + page_size; 177 178 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 179 if (pfn_valid(vmemmap_section_start(start))) 180 return 1; 181 182 return 0; 183 } 184 185 /* On hash-based CPUs, the vmemmap is bolted in the hash table. 186 * 187 * On Book3E CPUs, the vmemmap is currently mapped in the top half of 188 * the vmalloc space using normal page tables, though the size of 189 * pages encoded in the PTEs can be different 190 */ 191 192 #ifdef CONFIG_PPC_BOOK3E 193 static void __meminit vmemmap_create_mapping(unsigned long start, 194 unsigned long page_size, 195 unsigned long phys) 196 { 197 /* Create a PTE encoding without page size */ 198 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | 199 _PAGE_KERNEL_RW; 200 201 /* PTEs only contain page size encodings up to 32M */ 202 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); 203 204 /* Encode the size in the PTE */ 205 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; 206 207 /* For each PTE for that area, map things. Note that we don't 208 * increment phys because all PTEs are of the large size and 209 * thus must have the low bits clear 210 */ 211 for (i = 0; i < page_size; i += PAGE_SIZE) 212 BUG_ON(map_kernel_page(start + i, phys, flags)); 213 } 214 #else /* CONFIG_PPC_BOOK3E */ 215 static void __meminit vmemmap_create_mapping(unsigned long start, 216 unsigned long page_size, 217 unsigned long phys) 218 { 219 int mapped = htab_bolt_mapping(start, start + page_size, phys, 220 PAGE_KERNEL, mmu_vmemmap_psize, 221 mmu_kernel_ssize); 222 BUG_ON(mapped < 0); 223 } 224 #endif /* CONFIG_PPC_BOOK3E */ 225 226 struct vmemmap_backing *vmemmap_list; 227 228 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 229 { 230 static struct vmemmap_backing *next; 231 static int num_left; 232 233 /* allocate a page when required and hand out chunks */ 234 if (!next || !num_left) { 235 next = vmemmap_alloc_block(PAGE_SIZE, node); 236 if (unlikely(!next)) { 237 WARN_ON(1); 238 return NULL; 239 } 240 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 241 } 242 243 num_left--; 244 245 return next++; 246 } 247 248 static __meminit void vmemmap_list_populate(unsigned long phys, 249 unsigned long start, 250 int node) 251 { 252 struct vmemmap_backing *vmem_back; 253 254 vmem_back = vmemmap_list_alloc(node); 255 if (unlikely(!vmem_back)) { 256 WARN_ON(1); 257 return; 258 } 259 260 vmem_back->phys = phys; 261 vmem_back->virt_addr = start; 262 vmem_back->list = vmemmap_list; 263 264 vmemmap_list = vmem_back; 265 } 266 267 int __meminit vmemmap_populate(struct page *start_page, 268 unsigned long nr_pages, int node) 269 { 270 unsigned long start = (unsigned long)start_page; 271 unsigned long end = (unsigned long)(start_page + nr_pages); 272 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 273 274 /* Align to the page size of the linear mapping. */ 275 start = _ALIGN_DOWN(start, page_size); 276 277 pr_debug("vmemmap_populate page %p, %ld pages, node %d\n", 278 start_page, nr_pages, node); 279 pr_debug(" -> map %lx..%lx\n", start, end); 280 281 for (; start < end; start += page_size) { 282 void *p; 283 284 if (vmemmap_populated(start, page_size)) 285 continue; 286 287 p = vmemmap_alloc_block(page_size, node); 288 if (!p) 289 return -ENOMEM; 290 291 vmemmap_list_populate(__pa(p), start, node); 292 293 pr_debug(" * %016lx..%016lx allocated at %p\n", 294 start, start + page_size, p); 295 296 vmemmap_create_mapping(start, page_size, __pa(p)); 297 } 298 299 return 0; 300 } 301 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 302 303