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/lmb.h> 44 #include <linux/hugetlb.h> 45 46 #include <asm/pgalloc.h> 47 #include <asm/page.h> 48 #include <asm/prom.h> 49 #include <asm/rtas.h> 50 #include <asm/io.h> 51 #include <asm/mmu_context.h> 52 #include <asm/pgtable.h> 53 #include <asm/mmu.h> 54 #include <asm/uaccess.h> 55 #include <asm/smp.h> 56 #include <asm/machdep.h> 57 #include <asm/tlb.h> 58 #include <asm/eeh.h> 59 #include <asm/processor.h> 60 #include <asm/mmzone.h> 61 #include <asm/cputable.h> 62 #include <asm/sections.h> 63 #include <asm/system.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 phys_addr_t kernstart_addr; 82 83 void free_initmem(void) 84 { 85 unsigned long addr; 86 87 addr = (unsigned long)__init_begin; 88 for (; addr < (unsigned long)__init_end; addr += PAGE_SIZE) { 89 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE); 90 ClearPageReserved(virt_to_page(addr)); 91 init_page_count(virt_to_page(addr)); 92 free_page(addr); 93 totalram_pages++; 94 } 95 printk ("Freeing unused kernel memory: %luk freed\n", 96 ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10); 97 } 98 99 #ifdef CONFIG_BLK_DEV_INITRD 100 void free_initrd_mem(unsigned long start, unsigned long end) 101 { 102 if (start < end) 103 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); 104 for (; start < end; start += PAGE_SIZE) { 105 ClearPageReserved(virt_to_page(start)); 106 init_page_count(virt_to_page(start)); 107 free_page(start); 108 totalram_pages++; 109 } 110 } 111 #endif 112 113 static void pgd_ctor(void *addr) 114 { 115 memset(addr, 0, PGD_TABLE_SIZE); 116 } 117 118 static void pmd_ctor(void *addr) 119 { 120 memset(addr, 0, PMD_TABLE_SIZE); 121 } 122 123 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; 124 125 /* 126 * Create a kmem_cache() for pagetables. This is not used for PTE 127 * pages - they're linked to struct page, come from the normal free 128 * pages pool and have a different entry size (see real_pte_t) to 129 * everything else. Caches created by this function are used for all 130 * the higher level pagetables, and for hugepage pagetables. 131 */ 132 void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) 133 { 134 char *name; 135 unsigned long table_size = sizeof(void *) << shift; 136 unsigned long align = table_size; 137 138 /* When batching pgtable pointers for RCU freeing, we store 139 * the index size in the low bits. Table alignment must be 140 * big enough to fit it. 141 * 142 * Likewise, hugeapge pagetable pointers contain a (different) 143 * shift value in the low bits. All tables must be aligned so 144 * as to leave enough 0 bits in the address to contain it. */ 145 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, 146 HUGEPD_SHIFT_MASK + 1); 147 struct kmem_cache *new; 148 149 /* It would be nice if this was a BUILD_BUG_ON(), but at the 150 * moment, gcc doesn't seem to recognize is_power_of_2 as a 151 * constant expression, so so much for that. */ 152 BUG_ON(!is_power_of_2(minalign)); 153 BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); 154 155 if (PGT_CACHE(shift)) 156 return; /* Already have a cache of this size */ 157 158 align = max_t(unsigned long, align, minalign); 159 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); 160 new = kmem_cache_create(name, table_size, align, 0, ctor); 161 PGT_CACHE(shift) = new; 162 163 pr_debug("Allocated pgtable cache for order %d\n", shift); 164 } 165 166 167 void pgtable_cache_init(void) 168 { 169 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); 170 pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor); 171 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE)) 172 panic("Couldn't allocate pgtable caches"); 173 174 /* In all current configs, when the PUD index exists it's the 175 * same size as either the pgd or pmd index. Verify that the 176 * initialization above has also created a PUD cache. This 177 * will need re-examiniation if we add new possibilities for 178 * the pagetable layout. */ 179 BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); 180 } 181 182 #ifdef CONFIG_SPARSEMEM_VMEMMAP 183 /* 184 * Given an address within the vmemmap, determine the pfn of the page that 185 * represents the start of the section it is within. Note that we have to 186 * do this by hand as the proffered address may not be correctly aligned. 187 * Subtraction of non-aligned pointers produces undefined results. 188 */ 189 static unsigned long __meminit vmemmap_section_start(unsigned long page) 190 { 191 unsigned long offset = page - ((unsigned long)(vmemmap)); 192 193 /* Return the pfn of the start of the section. */ 194 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 195 } 196 197 /* 198 * Check if this vmemmap page is already initialised. If any section 199 * which overlaps this vmemmap page is initialised then this page is 200 * initialised already. 201 */ 202 static int __meminit vmemmap_populated(unsigned long start, int page_size) 203 { 204 unsigned long end = start + page_size; 205 206 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 207 if (pfn_valid(vmemmap_section_start(start))) 208 return 1; 209 210 return 0; 211 } 212 213 /* On hash-based CPUs, the vmemmap is bolted in the hash table. 214 * 215 * On Book3E CPUs, the vmemmap is currently mapped in the top half of 216 * the vmalloc space using normal page tables, though the size of 217 * pages encoded in the PTEs can be different 218 */ 219 220 #ifdef CONFIG_PPC_BOOK3E 221 static void __meminit vmemmap_create_mapping(unsigned long start, 222 unsigned long page_size, 223 unsigned long phys) 224 { 225 /* Create a PTE encoding without page size */ 226 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | 227 _PAGE_KERNEL_RW; 228 229 /* PTEs only contain page size encodings up to 32M */ 230 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); 231 232 /* Encode the size in the PTE */ 233 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; 234 235 /* For each PTE for that area, map things. Note that we don't 236 * increment phys because all PTEs are of the large size and 237 * thus must have the low bits clear 238 */ 239 for (i = 0; i < page_size; i += PAGE_SIZE) 240 BUG_ON(map_kernel_page(start + i, phys, flags)); 241 } 242 #else /* CONFIG_PPC_BOOK3E */ 243 static void __meminit vmemmap_create_mapping(unsigned long start, 244 unsigned long page_size, 245 unsigned long phys) 246 { 247 int mapped = htab_bolt_mapping(start, start + page_size, phys, 248 PAGE_KERNEL, mmu_vmemmap_psize, 249 mmu_kernel_ssize); 250 BUG_ON(mapped < 0); 251 } 252 #endif /* CONFIG_PPC_BOOK3E */ 253 254 int __meminit vmemmap_populate(struct page *start_page, 255 unsigned long nr_pages, int node) 256 { 257 unsigned long start = (unsigned long)start_page; 258 unsigned long end = (unsigned long)(start_page + nr_pages); 259 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 260 261 /* Align to the page size of the linear mapping. */ 262 start = _ALIGN_DOWN(start, page_size); 263 264 pr_debug("vmemmap_populate page %p, %ld pages, node %d\n", 265 start_page, nr_pages, node); 266 pr_debug(" -> map %lx..%lx\n", start, end); 267 268 for (; start < end; start += page_size) { 269 void *p; 270 271 if (vmemmap_populated(start, page_size)) 272 continue; 273 274 p = vmemmap_alloc_block(page_size, node); 275 if (!p) 276 return -ENOMEM; 277 278 pr_debug(" * %016lx..%016lx allocated at %p\n", 279 start, start + page_size, p); 280 281 vmemmap_create_mapping(start, page_size, __pa(p)); 282 } 283 284 return 0; 285 } 286 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 287