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/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 EXPORT_SYMBOL_GPL(memstart_addr); 83 phys_addr_t kernstart_addr; 84 EXPORT_SYMBOL_GPL(kernstart_addr); 85 86 void free_initmem(void) 87 { 88 unsigned long addr; 89 90 addr = (unsigned long)__init_begin; 91 for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) { 92 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); 93 ClearPageReserved(virt_to_page(addr)); 94 init_page_count(virt_to_page(addr)); 95 free_page(addr); 96 totalram_pages++; 97 } 98 printk ("Freeing unused kernel memory: %luk freed\n", 99 ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10); 100 } 101 102 static void pgd_ctor(void *addr) 103 { 104 memset(addr, 0, PGD_TABLE_SIZE); 105 } 106 107 static void pmd_ctor(void *addr) 108 { 109 memset(addr, 0, PMD_TABLE_SIZE); 110 } 111 112 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; 113 114 /* 115 * Create a kmem_cache() for pagetables. This is not used for PTE 116 * pages - they're linked to struct page, come from the normal free 117 * pages pool and have a different entry size (see real_pte_t) to 118 * everything else. Caches created by this function are used for all 119 * the higher level pagetables, and for hugepage pagetables. 120 */ 121 void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) 122 { 123 char *name; 124 unsigned long table_size = sizeof(void *) << shift; 125 unsigned long align = table_size; 126 127 /* When batching pgtable pointers for RCU freeing, we store 128 * the index size in the low bits. Table alignment must be 129 * big enough to fit it. 130 * 131 * Likewise, hugeapge pagetable pointers contain a (different) 132 * shift value in the low bits. All tables must be aligned so 133 * as to leave enough 0 bits in the address to contain it. */ 134 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, 135 HUGEPD_SHIFT_MASK + 1); 136 struct kmem_cache *new; 137 138 /* It would be nice if this was a BUILD_BUG_ON(), but at the 139 * moment, gcc doesn't seem to recognize is_power_of_2 as a 140 * constant expression, so so much for that. */ 141 BUG_ON(!is_power_of_2(minalign)); 142 BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); 143 144 if (PGT_CACHE(shift)) 145 return; /* Already have a cache of this size */ 146 147 align = max_t(unsigned long, align, minalign); 148 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); 149 new = kmem_cache_create(name, table_size, align, 0, ctor); 150 PGT_CACHE(shift) = new; 151 152 pr_debug("Allocated pgtable cache for order %d\n", shift); 153 } 154 155 156 void pgtable_cache_init(void) 157 { 158 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); 159 pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor); 160 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE)) 161 panic("Couldn't allocate pgtable caches"); 162 163 /* In all current configs, when the PUD index exists it's the 164 * same size as either the pgd or pmd index. Verify that the 165 * initialization above has also created a PUD cache. This 166 * will need re-examiniation if we add new possibilities for 167 * the pagetable layout. */ 168 BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); 169 } 170 171 #ifdef CONFIG_SPARSEMEM_VMEMMAP 172 /* 173 * Given an address within the vmemmap, determine the pfn of the page that 174 * represents the start of the section it is within. Note that we have to 175 * do this by hand as the proffered address may not be correctly aligned. 176 * Subtraction of non-aligned pointers produces undefined results. 177 */ 178 static unsigned long __meminit vmemmap_section_start(unsigned long page) 179 { 180 unsigned long offset = page - ((unsigned long)(vmemmap)); 181 182 /* Return the pfn of the start of the section. */ 183 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 184 } 185 186 /* 187 * Check if this vmemmap page is already initialised. If any section 188 * which overlaps this vmemmap page is initialised then this page is 189 * initialised already. 190 */ 191 static int __meminit vmemmap_populated(unsigned long start, int page_size) 192 { 193 unsigned long end = start + page_size; 194 195 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 196 if (pfn_valid(vmemmap_section_start(start))) 197 return 1; 198 199 return 0; 200 } 201 202 /* On hash-based CPUs, the vmemmap is bolted in the hash table. 203 * 204 * On Book3E CPUs, the vmemmap is currently mapped in the top half of 205 * the vmalloc space using normal page tables, though the size of 206 * pages encoded in the PTEs can be different 207 */ 208 209 #ifdef CONFIG_PPC_BOOK3E 210 static void __meminit vmemmap_create_mapping(unsigned long start, 211 unsigned long page_size, 212 unsigned long phys) 213 { 214 /* Create a PTE encoding without page size */ 215 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | 216 _PAGE_KERNEL_RW; 217 218 /* PTEs only contain page size encodings up to 32M */ 219 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); 220 221 /* Encode the size in the PTE */ 222 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; 223 224 /* For each PTE for that area, map things. Note that we don't 225 * increment phys because all PTEs are of the large size and 226 * thus must have the low bits clear 227 */ 228 for (i = 0; i < page_size; i += PAGE_SIZE) 229 BUG_ON(map_kernel_page(start + i, phys, flags)); 230 } 231 #else /* CONFIG_PPC_BOOK3E */ 232 static void __meminit vmemmap_create_mapping(unsigned long start, 233 unsigned long page_size, 234 unsigned long phys) 235 { 236 int mapped = htab_bolt_mapping(start, start + page_size, phys, 237 PAGE_KERNEL, mmu_vmemmap_psize, 238 mmu_kernel_ssize); 239 BUG_ON(mapped < 0); 240 } 241 #endif /* CONFIG_PPC_BOOK3E */ 242 243 struct vmemmap_backing *vmemmap_list; 244 245 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 246 { 247 static struct vmemmap_backing *next; 248 static int num_left; 249 250 /* allocate a page when required and hand out chunks */ 251 if (!next || !num_left) { 252 next = vmemmap_alloc_block(PAGE_SIZE, node); 253 if (unlikely(!next)) { 254 WARN_ON(1); 255 return NULL; 256 } 257 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 258 } 259 260 num_left--; 261 262 return next++; 263 } 264 265 static __meminit void vmemmap_list_populate(unsigned long phys, 266 unsigned long start, 267 int node) 268 { 269 struct vmemmap_backing *vmem_back; 270 271 vmem_back = vmemmap_list_alloc(node); 272 if (unlikely(!vmem_back)) { 273 WARN_ON(1); 274 return; 275 } 276 277 vmem_back->phys = phys; 278 vmem_back->virt_addr = start; 279 vmem_back->list = vmemmap_list; 280 281 vmemmap_list = vmem_back; 282 } 283 284 int __meminit vmemmap_populate(struct page *start_page, 285 unsigned long nr_pages, int node) 286 { 287 unsigned long start = (unsigned long)start_page; 288 unsigned long end = (unsigned long)(start_page + nr_pages); 289 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 290 291 /* Align to the page size of the linear mapping. */ 292 start = _ALIGN_DOWN(start, page_size); 293 294 pr_debug("vmemmap_populate page %p, %ld pages, node %d\n", 295 start_page, nr_pages, node); 296 pr_debug(" -> map %lx..%lx\n", start, end); 297 298 for (; start < end; start += page_size) { 299 void *p; 300 301 if (vmemmap_populated(start, page_size)) 302 continue; 303 304 p = vmemmap_alloc_block(page_size, node); 305 if (!p) 306 return -ENOMEM; 307 308 vmemmap_list_populate(__pa(p), start, node); 309 310 pr_debug(" * %016lx..%016lx allocated at %p\n", 311 start, start + page_size, p); 312 313 vmemmap_create_mapping(start, page_size, __pa(p)); 314 } 315 316 return 0; 317 } 318 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 319 320