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 PGTABLE_RANGE > USER_VSID_RANGE 70#warning Limited user VSID range means pagetable space is wasted 71#endif 72 73#if (TASK_SIZE_USER64 < 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 78phys_addr_t memstart_addr = ~0; 79EXPORT_SYMBOL_GPL(memstart_addr); 80phys_addr_t kernstart_addr; 81EXPORT_SYMBOL_GPL(kernstart_addr); 82 83static void pgd_ctor(void *addr) 84{ 85 memset(addr, 0, PGD_TABLE_SIZE); 86} 87 88static void pmd_ctor(void *addr) 89{ 90#ifdef CONFIG_TRANSPARENT_HUGEPAGE 91 memset(addr, 0, PMD_TABLE_SIZE * 2); 92#else 93 memset(addr, 0, PMD_TABLE_SIZE); 94#endif 95} 96 97struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; 98 99/* 100 * Create a kmem_cache() for pagetables. This is not used for PTE 101 * pages - they're linked to struct page, come from the normal free 102 * pages pool and have a different entry size (see real_pte_t) to 103 * everything else. Caches created by this function are used for all 104 * the higher level pagetables, and for hugepage pagetables. 105 */ 106void pgtable_cache_add(unsigned shift, void (*ctor)(void *)) 107{ 108 char *name; 109 unsigned long table_size = sizeof(void *) << shift; 110 unsigned long align = table_size; 111 112 /* When batching pgtable pointers for RCU freeing, we store 113 * the index size in the low bits. Table alignment must be 114 * big enough to fit it. 115 * 116 * Likewise, hugeapge pagetable pointers contain a (different) 117 * shift value in the low bits. All tables must be aligned so 118 * as to leave enough 0 bits in the address to contain it. */ 119 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, 120 HUGEPD_SHIFT_MASK + 1); 121 struct kmem_cache *new; 122 123 /* It would be nice if this was a BUILD_BUG_ON(), but at the 124 * moment, gcc doesn't seem to recognize is_power_of_2 as a 125 * constant expression, so so much for that. */ 126 BUG_ON(!is_power_of_2(minalign)); 127 BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE)); 128 129 if (PGT_CACHE(shift)) 130 return; /* Already have a cache of this size */ 131 132 align = max_t(unsigned long, align, minalign); 133 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); 134 new = kmem_cache_create(name, table_size, align, 0, ctor); 135 kfree(name); 136 pgtable_cache[shift - 1] = new; 137 pr_debug("Allocated pgtable cache for order %d\n", shift); 138} 139 140 141void pgtable_cache_init(void) 142{ 143 pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); 144 pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor); 145 if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_CACHE_INDEX)) 146 panic("Couldn't allocate pgtable caches"); 147 /* In all current configs, when the PUD index exists it's the 148 * same size as either the pgd or pmd index. Verify that the 149 * initialization above has also created a PUD cache. This 150 * will need re-examiniation if we add new possibilities for 151 * the pagetable layout. */ 152 BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); 153} 154 155#ifdef CONFIG_SPARSEMEM_VMEMMAP 156/* 157 * Given an address within the vmemmap, determine the pfn of the page that 158 * represents the start of the section it is within. Note that we have to 159 * do this by hand as the proffered address may not be correctly aligned. 160 * Subtraction of non-aligned pointers produces undefined results. 161 */ 162static unsigned long __meminit vmemmap_section_start(unsigned long page) 163{ 164 unsigned long offset = page - ((unsigned long)(vmemmap)); 165 166 /* Return the pfn of the start of the section. */ 167 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 168} 169 170/* 171 * Check if this vmemmap page is already initialised. If any section 172 * which overlaps this vmemmap page is initialised then this page is 173 * initialised already. 174 */ 175static int __meminit vmemmap_populated(unsigned long start, int page_size) 176{ 177 unsigned long end = start + page_size; 178 start = (unsigned long)(pfn_to_page(vmemmap_section_start(start))); 179 180 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 181 if (pfn_valid(page_to_pfn((struct page *)start))) 182 return 1; 183 184 return 0; 185} 186 187/* On hash-based CPUs, the vmemmap is bolted in the hash table. 188 * 189 * On Book3E CPUs, the vmemmap is currently mapped in the top half of 190 * the vmalloc space using normal page tables, though the size of 191 * pages encoded in the PTEs can be different 192 */ 193 194#ifdef CONFIG_PPC_BOOK3E 195static void __meminit vmemmap_create_mapping(unsigned long start, 196 unsigned long page_size, 197 unsigned long phys) 198{ 199 /* Create a PTE encoding without page size */ 200 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | 201 _PAGE_KERNEL_RW; 202 203 /* PTEs only contain page size encodings up to 32M */ 204 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); 205 206 /* Encode the size in the PTE */ 207 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; 208 209 /* For each PTE for that area, map things. Note that we don't 210 * increment phys because all PTEs are of the large size and 211 * thus must have the low bits clear 212 */ 213 for (i = 0; i < page_size; i += PAGE_SIZE) 214 BUG_ON(map_kernel_page(start + i, phys, flags)); 215} 216 217#ifdef CONFIG_MEMORY_HOTPLUG 218static void vmemmap_remove_mapping(unsigned long start, 219 unsigned long page_size) 220{ 221} 222#endif 223#else /* CONFIG_PPC_BOOK3E */ 224static void __meminit vmemmap_create_mapping(unsigned long start, 225 unsigned long page_size, 226 unsigned long phys) 227{ 228 int mapped = htab_bolt_mapping(start, start + page_size, phys, 229 pgprot_val(PAGE_KERNEL), 230 mmu_vmemmap_psize, 231 mmu_kernel_ssize); 232 BUG_ON(mapped < 0); 233} 234 235#ifdef CONFIG_MEMORY_HOTPLUG 236static void vmemmap_remove_mapping(unsigned long start, 237 unsigned long page_size) 238{ 239 int mapped = htab_remove_mapping(start, start + page_size, 240 mmu_vmemmap_psize, 241 mmu_kernel_ssize); 242 BUG_ON(mapped < 0); 243} 244#endif 245 246#endif /* CONFIG_PPC_BOOK3E */ 247 248struct vmemmap_backing *vmemmap_list; 249static struct vmemmap_backing *next; 250static int num_left; 251static int num_freed; 252 253static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 254{ 255 struct vmemmap_backing *vmem_back; 256 /* get from freed entries first */ 257 if (num_freed) { 258 num_freed--; 259 vmem_back = next; 260 next = next->list; 261 262 return vmem_back; 263 } 264 265 /* allocate a page when required and hand out chunks */ 266 if (!num_left) { 267 next = vmemmap_alloc_block(PAGE_SIZE, node); 268 if (unlikely(!next)) { 269 WARN_ON(1); 270 return NULL; 271 } 272 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 273 } 274 275 num_left--; 276 277 return next++; 278} 279 280static __meminit void vmemmap_list_populate(unsigned long phys, 281 unsigned long start, 282 int node) 283{ 284 struct vmemmap_backing *vmem_back; 285 286 vmem_back = vmemmap_list_alloc(node); 287 if (unlikely(!vmem_back)) { 288 WARN_ON(1); 289 return; 290 } 291 292 vmem_back->phys = phys; 293 vmem_back->virt_addr = start; 294 vmem_back->list = vmemmap_list; 295 296 vmemmap_list = vmem_back; 297} 298 299int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 300{ 301 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 302 303 /* Align to the page size of the linear mapping. */ 304 start = _ALIGN_DOWN(start, page_size); 305 306 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 307 308 for (; start < end; start += page_size) { 309 void *p; 310 311 if (vmemmap_populated(start, page_size)) 312 continue; 313 314 p = vmemmap_alloc_block(page_size, node); 315 if (!p) 316 return -ENOMEM; 317 318 vmemmap_list_populate(__pa(p), start, node); 319 320 pr_debug(" * %016lx..%016lx allocated at %p\n", 321 start, start + page_size, p); 322 323 vmemmap_create_mapping(start, page_size, __pa(p)); 324 } 325 326 return 0; 327} 328 329#ifdef CONFIG_MEMORY_HOTPLUG 330static unsigned long vmemmap_list_free(unsigned long start) 331{ 332 struct vmemmap_backing *vmem_back, *vmem_back_prev; 333 334 vmem_back_prev = vmem_back = vmemmap_list; 335 336 /* look for it with prev pointer recorded */ 337 for (; vmem_back; vmem_back = vmem_back->list) { 338 if (vmem_back->virt_addr == start) 339 break; 340 vmem_back_prev = vmem_back; 341 } 342 343 if (unlikely(!vmem_back)) { 344 WARN_ON(1); 345 return 0; 346 } 347 348 /* remove it from vmemmap_list */ 349 if (vmem_back == vmemmap_list) /* remove head */ 350 vmemmap_list = vmem_back->list; 351 else 352 vmem_back_prev->list = vmem_back->list; 353 354 /* next point to this freed entry */ 355 vmem_back->list = next; 356 next = vmem_back; 357 num_freed++; 358 359 return vmem_back->phys; 360} 361 362void __ref vmemmap_free(unsigned long start, unsigned long end) 363{ 364 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 365 366 start = _ALIGN_DOWN(start, page_size); 367 368 pr_debug("vmemmap_free %lx...%lx\n", start, end); 369 370 for (; start < end; start += page_size) { 371 unsigned long addr; 372 373 /* 374 * the section has already be marked as invalid, so 375 * vmemmap_populated() true means some other sections still 376 * in this page, so skip it. 377 */ 378 if (vmemmap_populated(start, page_size)) 379 continue; 380 381 addr = vmemmap_list_free(start); 382 if (addr) { 383 struct page *page = pfn_to_page(addr >> PAGE_SHIFT); 384 385 if (PageReserved(page)) { 386 /* allocated from bootmem */ 387 if (page_size < PAGE_SIZE) { 388 /* 389 * this shouldn't happen, but if it is 390 * the case, leave the memory there 391 */ 392 WARN_ON_ONCE(1); 393 } else { 394 unsigned int nr_pages = 395 1 << get_order(page_size); 396 while (nr_pages--) 397 free_reserved_page(page++); 398 } 399 } else 400 free_pages((unsigned long)(__va(addr)), 401 get_order(page_size)); 402 403 vmemmap_remove_mapping(start, page_size); 404 } 405 } 406} 407#endif 408void register_page_bootmem_memmap(unsigned long section_nr, 409 struct page *start_page, unsigned long size) 410{ 411} 412 413/* 414 * We do not have access to the sparsemem vmemmap, so we fallback to 415 * walking the list of sparsemem blocks which we already maintain for 416 * the sake of crashdump. In the long run, we might want to maintain 417 * a tree if performance of that linear walk becomes a problem. 418 * 419 * realmode_pfn_to_page functions can fail due to: 420 * 1) As real sparsemem blocks do not lay in RAM continously (they 421 * are in virtual address space which is not available in the real mode), 422 * the requested page struct can be split between blocks so get_page/put_page 423 * may fail. 424 * 2) When huge pages are used, the get_page/put_page API will fail 425 * in real mode as the linked addresses in the page struct are virtual 426 * too. 427 */ 428struct page *realmode_pfn_to_page(unsigned long pfn) 429{ 430 struct vmemmap_backing *vmem_back; 431 struct page *page; 432 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 433 unsigned long pg_va = (unsigned long) pfn_to_page(pfn); 434 435 for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) { 436 if (pg_va < vmem_back->virt_addr) 437 continue; 438 439 /* After vmemmap_list entry free is possible, need check all */ 440 if ((pg_va + sizeof(struct page)) <= 441 (vmem_back->virt_addr + page_size)) { 442 page = (struct page *) (vmem_back->phys + pg_va - 443 vmem_back->virt_addr); 444 return page; 445 } 446 } 447 448 /* Probably that page struct is split between real pages */ 449 return NULL; 450} 451EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 452 453#elif defined(CONFIG_FLATMEM) 454 455struct page *realmode_pfn_to_page(unsigned long pfn) 456{ 457 struct page *page = pfn_to_page(pfn); 458 return page; 459} 460EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 461 462#endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */ 463