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 pgtable_cache[shift - 1] = new; 133 pr_debug("Allocated pgtable cache for order %d\n", shift); 134 } 135 136 137 void pgtable_cache_init(void) 138 { 139 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); 140 pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor); 141 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE)) 142 panic("Couldn't allocate pgtable caches"); 143 144 /* In all current configs, when the PUD index exists it's the 145 * same size as either the pgd or pmd index. Verify that the 146 * initialization above has also created a PUD cache. This 147 * will need re-examiniation if we add new possibilities for 148 * the pagetable layout. */ 149 BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); 150 } 151 152 #ifdef CONFIG_SPARSEMEM_VMEMMAP 153 /* 154 * Given an address within the vmemmap, determine the pfn of the page that 155 * represents the start of the section it is within. Note that we have to 156 * do this by hand as the proffered address may not be correctly aligned. 157 * Subtraction of non-aligned pointers produces undefined results. 158 */ 159 static unsigned long __meminit vmemmap_section_start(unsigned long page) 160 { 161 unsigned long offset = page - ((unsigned long)(vmemmap)); 162 163 /* Return the pfn of the start of the section. */ 164 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 165 } 166 167 /* 168 * Check if this vmemmap page is already initialised. If any section 169 * which overlaps this vmemmap page is initialised then this page is 170 * initialised already. 171 */ 172 static int __meminit vmemmap_populated(unsigned long start, int page_size) 173 { 174 unsigned long end = start + page_size; 175 176 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 177 if (pfn_valid(vmemmap_section_start(start))) 178 return 1; 179 180 return 0; 181 } 182 183 /* On hash-based CPUs, the vmemmap is bolted in the hash table. 184 * 185 * On Book3E CPUs, the vmemmap is currently mapped in the top half of 186 * the vmalloc space using normal page tables, though the size of 187 * pages encoded in the PTEs can be different 188 */ 189 190 #ifdef CONFIG_PPC_BOOK3E 191 static void __meminit vmemmap_create_mapping(unsigned long start, 192 unsigned long page_size, 193 unsigned long phys) 194 { 195 /* Create a PTE encoding without page size */ 196 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | 197 _PAGE_KERNEL_RW; 198 199 /* PTEs only contain page size encodings up to 32M */ 200 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); 201 202 /* Encode the size in the PTE */ 203 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; 204 205 /* For each PTE for that area, map things. Note that we don't 206 * increment phys because all PTEs are of the large size and 207 * thus must have the low bits clear 208 */ 209 for (i = 0; i < page_size; i += PAGE_SIZE) 210 BUG_ON(map_kernel_page(start + i, phys, flags)); 211 } 212 #else /* CONFIG_PPC_BOOK3E */ 213 static void __meminit vmemmap_create_mapping(unsigned long start, 214 unsigned long page_size, 215 unsigned long phys) 216 { 217 int mapped = htab_bolt_mapping(start, start + page_size, phys, 218 pgprot_val(PAGE_KERNEL), 219 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(unsigned long start, unsigned long end, int node) 267 { 268 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 269 270 /* Align to the page size of the linear mapping. */ 271 start = _ALIGN_DOWN(start, page_size); 272 273 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 274 275 for (; start < end; start += page_size) { 276 void *p; 277 278 if (vmemmap_populated(start, page_size)) 279 continue; 280 281 p = vmemmap_alloc_block(page_size, node); 282 if (!p) 283 return -ENOMEM; 284 285 vmemmap_list_populate(__pa(p), start, node); 286 287 pr_debug(" * %016lx..%016lx allocated at %p\n", 288 start, start + page_size, p); 289 290 vmemmap_create_mapping(start, page_size, __pa(p)); 291 } 292 293 return 0; 294 } 295 296 void vmemmap_free(unsigned long start, unsigned long end) 297 { 298 } 299 300 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 301 302