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 #ifdef CONFIG_BLK_DEV_INITRD 103 void free_initrd_mem(unsigned long start, unsigned long end) 104 { 105 if (start < end) 106 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 107 for (; start < end; start += PAGE_SIZE) { 108 ClearPageReserved(virt_to_page(start)); 109 init_page_count(virt_to_page(start)); 110 free_page(start); 111 totalram_pages++; 112 } 113 } 114 #endif 115 116 static void pgd_ctor(void *addr) 117 { 118 memset(addr, 0, PGD_TABLE_SIZE); 119 } 120 121 static void pmd_ctor(void *addr) 122 { 123 memset(addr, 0, PMD_TABLE_SIZE); 124 } 125 126 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; 127 128 /* 129 * Create a kmem_cache() for pagetables. This is not used for PTE 130 * pages - they're linked to struct page, come from the normal free 131 * pages pool and have a different entry size (see real_pte_t) to 132 * everything else. Caches created by this function are used for all 133 * the higher level pagetables, and for hugepage pagetables. 134 */ 135 void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) 136 { 137 char *name; 138 unsigned long table_size = sizeof(void *) << shift; 139 unsigned long align = table_size; 140 141 /* When batching pgtable pointers for RCU freeing, we store 142 * the index size in the low bits. Table alignment must be 143 * big enough to fit it. 144 * 145 * Likewise, hugeapge pagetable pointers contain a (different) 146 * shift value in the low bits. All tables must be aligned so 147 * as to leave enough 0 bits in the address to contain it. */ 148 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, 149 HUGEPD_SHIFT_MASK + 1); 150 struct kmem_cache *new; 151 152 /* It would be nice if this was a BUILD_BUG_ON(), but at the 153 * moment, gcc doesn't seem to recognize is_power_of_2 as a 154 * constant expression, so so much for that. */ 155 BUG_ON(!is_power_of_2(minalign)); 156 BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); 157 158 if (PGT_CACHE(shift)) 159 return; /* Already have a cache of this size */ 160 161 align = max_t(unsigned long, align, minalign); 162 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); 163 new = kmem_cache_create(name, table_size, align, 0, ctor); 164 PGT_CACHE(shift) = new; 165 166 pr_debug("Allocated pgtable cache for order %d\n", shift); 167 } 168 169 170 void pgtable_cache_init(void) 171 { 172 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); 173 pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor); 174 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE)) 175 panic("Couldn't allocate pgtable caches"); 176 177 /* In all current configs, when the PUD index exists it's the 178 * same size as either the pgd or pmd index. Verify that the 179 * initialization above has also created a PUD cache. This 180 * will need re-examiniation if we add new possibilities for 181 * the pagetable layout. */ 182 BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); 183 } 184 185 #ifdef CONFIG_SPARSEMEM_VMEMMAP 186 /* 187 * Given an address within the vmemmap, determine the pfn of the page that 188 * represents the start of the section it is within. Note that we have to 189 * do this by hand as the proffered address may not be correctly aligned. 190 * Subtraction of non-aligned pointers produces undefined results. 191 */ 192 static unsigned long __meminit vmemmap_section_start(unsigned long page) 193 { 194 unsigned long offset = page - ((unsigned long)(vmemmap)); 195 196 /* Return the pfn of the start of the section. */ 197 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 198 } 199 200 /* 201 * Check if this vmemmap page is already initialised. If any section 202 * which overlaps this vmemmap page is initialised then this page is 203 * initialised already. 204 */ 205 static int __meminit vmemmap_populated(unsigned long start, int page_size) 206 { 207 unsigned long end = start + page_size; 208 209 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 210 if (pfn_valid(vmemmap_section_start(start))) 211 return 1; 212 213 return 0; 214 } 215 216 /* On hash-based CPUs, the vmemmap is bolted in the hash table. 217 * 218 * On Book3E CPUs, the vmemmap is currently mapped in the top half of 219 * the vmalloc space using normal page tables, though the size of 220 * pages encoded in the PTEs can be different 221 */ 222 223 #ifdef CONFIG_PPC_BOOK3E 224 static void __meminit vmemmap_create_mapping(unsigned long start, 225 unsigned long page_size, 226 unsigned long phys) 227 { 228 /* Create a PTE encoding without page size */ 229 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | 230 _PAGE_KERNEL_RW; 231 232 /* PTEs only contain page size encodings up to 32M */ 233 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); 234 235 /* Encode the size in the PTE */ 236 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; 237 238 /* For each PTE for that area, map things. Note that we don't 239 * increment phys because all PTEs are of the large size and 240 * thus must have the low bits clear 241 */ 242 for (i = 0; i < page_size; i += PAGE_SIZE) 243 BUG_ON(map_kernel_page(start + i, phys, flags)); 244 } 245 #else /* CONFIG_PPC_BOOK3E */ 246 static void __meminit vmemmap_create_mapping(unsigned long start, 247 unsigned long page_size, 248 unsigned long phys) 249 { 250 int mapped = htab_bolt_mapping(start, start + page_size, phys, 251 PAGE_KERNEL, mmu_vmemmap_psize, 252 mmu_kernel_ssize); 253 BUG_ON(mapped < 0); 254 } 255 #endif /* CONFIG_PPC_BOOK3E */ 256 257 struct vmemmap_backing *vmemmap_list; 258 259 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 260 { 261 static struct vmemmap_backing *next; 262 static int num_left; 263 264 /* allocate a page when required and hand out chunks */ 265 if (!next || !num_left) { 266 next = vmemmap_alloc_block(PAGE_SIZE, node); 267 if (unlikely(!next)) { 268 WARN_ON(1); 269 return NULL; 270 } 271 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 272 } 273 274 num_left--; 275 276 return next++; 277 } 278 279 static __meminit void vmemmap_list_populate(unsigned long phys, 280 unsigned long start, 281 int node) 282 { 283 struct vmemmap_backing *vmem_back; 284 285 vmem_back = vmemmap_list_alloc(node); 286 if (unlikely(!vmem_back)) { 287 WARN_ON(1); 288 return; 289 } 290 291 vmem_back->phys = phys; 292 vmem_back->virt_addr = start; 293 vmem_back->list = vmemmap_list; 294 295 vmemmap_list = vmem_back; 296 } 297 298 int __meminit vmemmap_populate(struct page *start_page, 299 unsigned long nr_pages, int node) 300 { 301 unsigned long start = (unsigned long)start_page; 302 unsigned long end = (unsigned long)(start_page + nr_pages); 303 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 304 305 /* Align to the page size of the linear mapping. */ 306 start = _ALIGN_DOWN(start, page_size); 307 308 pr_debug("vmemmap_populate page %p, %ld pages, node %d\n", 309 start_page, nr_pages, node); 310 pr_debug(" -> map %lx..%lx\n", start, end); 311 312 for (; start < end; start += page_size) { 313 void *p; 314 315 if (vmemmap_populated(start, page_size)) 316 continue; 317 318 p = vmemmap_alloc_block(page_size, node); 319 if (!p) 320 return -ENOMEM; 321 322 vmemmap_list_populate(__pa(p), start, node); 323 324 pr_debug(" * %016lx..%016lx allocated at %p\n", 325 start, start + page_size, p); 326 327 vmemmap_create_mapping(start, page_size, __pa(p)); 328 } 329 330 return 0; 331 } 332 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 333 334