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/highmem.h> 38 #include <linux/idr.h> 39 #include <linux/nodemask.h> 40 #include <linux/module.h> 41 #include <linux/poison.h> 42 #include <linux/memblock.h> 43 #include <linux/hugetlb.h> 44 #include <linux/slab.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/iommu.h> 64 #include <asm/vdso.h> 65 66 #include "mmu_decl.h" 67 68 #ifdef CONFIG_PPC_STD_MMU_64 69 #if H_PGTABLE_RANGE > USER_VSID_RANGE 70 #warning Limited user VSID range means pagetable space is wasted 71 #endif 72 73 #if (TASK_SIZE_USER64 < H_PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE) 74 #warning TASK_SIZE is smaller than it needs to be. 75 #endif 76 #endif /* CONFIG_PPC_STD_MMU_64 */ 77 78 phys_addr_t memstart_addr = ~0; 79 EXPORT_SYMBOL_GPL(memstart_addr); 80 phys_addr_t kernstart_addr; 81 EXPORT_SYMBOL_GPL(kernstart_addr); 82 83 static void pgd_ctor(void *addr) 84 { 85 memset(addr, 0, PGD_TABLE_SIZE); 86 } 87 88 static void pud_ctor(void *addr) 89 { 90 memset(addr, 0, PUD_TABLE_SIZE); 91 } 92 93 static void pmd_ctor(void *addr) 94 { 95 memset(addr, 0, PMD_TABLE_SIZE); 96 } 97 98 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; 99 100 /* 101 * Create a kmem_cache() for pagetables. This is not used for PTE 102 * pages - they're linked to struct page, come from the normal free 103 * pages pool and have a different entry size (see real_pte_t) to 104 * everything else. Caches created by this function are used for all 105 * the higher level pagetables, and for hugepage pagetables. 106 */ 107 void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) 108 { 109 char *name; 110 unsigned long table_size = sizeof(void *) << shift; 111 unsigned long align = table_size; 112 113 /* When batching pgtable pointers for RCU freeing, we store 114 * the index size in the low bits. Table alignment must be 115 * big enough to fit it. 116 * 117 * Likewise, hugeapge pagetable pointers contain a (different) 118 * shift value in the low bits. All tables must be aligned so 119 * as to leave enough 0 bits in the address to contain it. */ 120 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, 121 HUGEPD_SHIFT_MASK + 1); 122 struct kmem_cache *new; 123 124 /* It would be nice if this was a BUILD_BUG_ON(), but at the 125 * moment, gcc doesn't seem to recognize is_power_of_2 as a 126 * constant expression, so so much for that. */ 127 BUG_ON(!is_power_of_2(minalign)); 128 BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); 129 130 if (PGT_CACHE(shift)) 131 return; /* Already have a cache of this size */ 132 133 align = max_t(unsigned long, align, minalign); 134 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); 135 new = kmem_cache_create(name, table_size, align, 0, ctor); 136 kfree(name); 137 pgtable_cache[shift - 1] = new; 138 pr_debug("Allocated pgtable cache for order %d\n", shift); 139 } 140 141 142 void pgtable_cache_init(void) 143 { 144 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); 145 pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor); 146 /* 147 * In all current configs, when the PUD index exists it's the 148 * same size as either the pgd or pmd index except with THP enabled 149 * on book3s 64 150 */ 151 if (PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)) 152 pgtable_cache_add(PUD_INDEX_SIZE, pud_ctor); 153 154 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_CACHE_INDEX)) 155 panic("Couldn't allocate pgtable caches"); 156 if (PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)) 157 panic("Couldn't allocate pud pgtable caches"); 158 } 159 160 #ifdef CONFIG_SPARSEMEM_VMEMMAP 161 /* 162 * Given an address within the vmemmap, determine the pfn of the page that 163 * represents the start of the section it is within. Note that we have to 164 * do this by hand as the proffered address may not be correctly aligned. 165 * Subtraction of non-aligned pointers produces undefined results. 166 */ 167 static unsigned long __meminit vmemmap_section_start(unsigned long page) 168 { 169 unsigned long offset = page - ((unsigned long)(vmemmap)); 170 171 /* Return the pfn of the start of the section. */ 172 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 173 } 174 175 /* 176 * Check if this vmemmap page is already initialised. If any section 177 * which overlaps this vmemmap page is initialised then this page is 178 * initialised already. 179 */ 180 static int __meminit vmemmap_populated(unsigned long start, int page_size) 181 { 182 unsigned long end = start + page_size; 183 start = (unsigned long)(pfn_to_page(vmemmap_section_start(start))); 184 185 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 186 if (pfn_valid(page_to_pfn((struct page *)start))) 187 return 1; 188 189 return 0; 190 } 191 192 struct vmemmap_backing *vmemmap_list; 193 static struct vmemmap_backing *next; 194 static int num_left; 195 static int num_freed; 196 197 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 198 { 199 struct vmemmap_backing *vmem_back; 200 /* get from freed entries first */ 201 if (num_freed) { 202 num_freed--; 203 vmem_back = next; 204 next = next->list; 205 206 return vmem_back; 207 } 208 209 /* allocate a page when required and hand out chunks */ 210 if (!num_left) { 211 next = vmemmap_alloc_block(PAGE_SIZE, node); 212 if (unlikely(!next)) { 213 WARN_ON(1); 214 return NULL; 215 } 216 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 217 } 218 219 num_left--; 220 221 return next++; 222 } 223 224 static __meminit void vmemmap_list_populate(unsigned long phys, 225 unsigned long start, 226 int node) 227 { 228 struct vmemmap_backing *vmem_back; 229 230 vmem_back = vmemmap_list_alloc(node); 231 if (unlikely(!vmem_back)) { 232 WARN_ON(1); 233 return; 234 } 235 236 vmem_back->phys = phys; 237 vmem_back->virt_addr = start; 238 vmem_back->list = vmemmap_list; 239 240 vmemmap_list = vmem_back; 241 } 242 243 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 244 { 245 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 246 247 /* Align to the page size of the linear mapping. */ 248 start = _ALIGN_DOWN(start, page_size); 249 250 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 251 252 for (; start < end; start += page_size) { 253 void *p; 254 int rc; 255 256 if (vmemmap_populated(start, page_size)) 257 continue; 258 259 p = vmemmap_alloc_block(page_size, node); 260 if (!p) 261 return -ENOMEM; 262 263 vmemmap_list_populate(__pa(p), start, node); 264 265 pr_debug(" * %016lx..%016lx allocated at %p\n", 266 start, start + page_size, p); 267 268 rc = vmemmap_create_mapping(start, page_size, __pa(p)); 269 if (rc < 0) { 270 pr_warning( 271 "vmemmap_populate: Unable to create vmemmap mapping: %d\n", 272 rc); 273 return -EFAULT; 274 } 275 } 276 277 return 0; 278 } 279 280 #ifdef CONFIG_MEMORY_HOTPLUG 281 static unsigned long vmemmap_list_free(unsigned long start) 282 { 283 struct vmemmap_backing *vmem_back, *vmem_back_prev; 284 285 vmem_back_prev = vmem_back = vmemmap_list; 286 287 /* look for it with prev pointer recorded */ 288 for (; vmem_back; vmem_back = vmem_back->list) { 289 if (vmem_back->virt_addr == start) 290 break; 291 vmem_back_prev = vmem_back; 292 } 293 294 if (unlikely(!vmem_back)) { 295 WARN_ON(1); 296 return 0; 297 } 298 299 /* remove it from vmemmap_list */ 300 if (vmem_back == vmemmap_list) /* remove head */ 301 vmemmap_list = vmem_back->list; 302 else 303 vmem_back_prev->list = vmem_back->list; 304 305 /* next point to this freed entry */ 306 vmem_back->list = next; 307 next = vmem_back; 308 num_freed++; 309 310 return vmem_back->phys; 311 } 312 313 void __ref vmemmap_free(unsigned long start, unsigned long end) 314 { 315 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 316 317 start = _ALIGN_DOWN(start, page_size); 318 319 pr_debug("vmemmap_free %lx...%lx\n", start, end); 320 321 for (; start < end; start += page_size) { 322 unsigned long addr; 323 324 /* 325 * the section has already be marked as invalid, so 326 * vmemmap_populated() true means some other sections still 327 * in this page, so skip it. 328 */ 329 if (vmemmap_populated(start, page_size)) 330 continue; 331 332 addr = vmemmap_list_free(start); 333 if (addr) { 334 struct page *page = pfn_to_page(addr >> PAGE_SHIFT); 335 336 if (PageReserved(page)) { 337 /* allocated from bootmem */ 338 if (page_size < PAGE_SIZE) { 339 /* 340 * this shouldn't happen, but if it is 341 * the case, leave the memory there 342 */ 343 WARN_ON_ONCE(1); 344 } else { 345 unsigned int nr_pages = 346 1 << get_order(page_size); 347 while (nr_pages--) 348 free_reserved_page(page++); 349 } 350 } else 351 free_pages((unsigned long)(__va(addr)), 352 get_order(page_size)); 353 354 vmemmap_remove_mapping(start, page_size); 355 } 356 } 357 } 358 #endif 359 void register_page_bootmem_memmap(unsigned long section_nr, 360 struct page *start_page, unsigned long size) 361 { 362 } 363 364 /* 365 * We do not have access to the sparsemem vmemmap, so we fallback to 366 * walking the list of sparsemem blocks which we already maintain for 367 * the sake of crashdump. In the long run, we might want to maintain 368 * a tree if performance of that linear walk becomes a problem. 369 * 370 * realmode_pfn_to_page functions can fail due to: 371 * 1) As real sparsemem blocks do not lay in RAM continously (they 372 * are in virtual address space which is not available in the real mode), 373 * the requested page struct can be split between blocks so get_page/put_page 374 * may fail. 375 * 2) When huge pages are used, the get_page/put_page API will fail 376 * in real mode as the linked addresses in the page struct are virtual 377 * too. 378 */ 379 struct page *realmode_pfn_to_page(unsigned long pfn) 380 { 381 struct vmemmap_backing *vmem_back; 382 struct page *page; 383 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 384 unsigned long pg_va = (unsigned long) pfn_to_page(pfn); 385 386 for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) { 387 if (pg_va < vmem_back->virt_addr) 388 continue; 389 390 /* After vmemmap_list entry free is possible, need check all */ 391 if ((pg_va + sizeof(struct page)) <= 392 (vmem_back->virt_addr + page_size)) { 393 page = (struct page *) (vmem_back->phys + pg_va - 394 vmem_back->virt_addr); 395 return page; 396 } 397 } 398 399 /* Probably that page struct is split between real pages */ 400 return NULL; 401 } 402 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 403 404 #elif defined(CONFIG_FLATMEM) 405 406 struct page *realmode_pfn_to_page(unsigned long pfn) 407 { 408 struct page *page = pfn_to_page(pfn); 409 return page; 410 } 411 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 412 413 #endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */ 414