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 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 /* On hash-based CPUs, the vmemmap is bolted in the hash table. 193 * 194 * On Book3E CPUs, the vmemmap is currently mapped in the top half of 195 * the vmalloc space using normal page tables, though the size of 196 * pages encoded in the PTEs can be different 197 */ 198 199 #ifdef CONFIG_PPC_BOOK3E 200 static int __meminit vmemmap_create_mapping(unsigned long start, 201 unsigned long page_size, 202 unsigned long phys) 203 { 204 /* Create a PTE encoding without page size */ 205 unsigned long i, flags = _PAGE_PRESENT | _PAGE_ACCESSED | 206 _PAGE_KERNEL_RW; 207 208 /* PTEs only contain page size encodings up to 32M */ 209 BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf); 210 211 /* Encode the size in the PTE */ 212 flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8; 213 214 /* For each PTE for that area, map things. Note that we don't 215 * increment phys because all PTEs are of the large size and 216 * thus must have the low bits clear 217 */ 218 for (i = 0; i < page_size; i += PAGE_SIZE) 219 BUG_ON(map_kernel_page(start + i, phys, flags)); 220 221 return 0; 222 } 223 224 #ifdef CONFIG_MEMORY_HOTPLUG 225 static void vmemmap_remove_mapping(unsigned long start, 226 unsigned long page_size) 227 { 228 } 229 #endif 230 #else /* CONFIG_PPC_BOOK3E */ 231 static int __meminit vmemmap_create_mapping(unsigned long start, 232 unsigned long page_size, 233 unsigned long phys) 234 { 235 int rc = htab_bolt_mapping(start, start + page_size, phys, 236 pgprot_val(PAGE_KERNEL), 237 mmu_vmemmap_psize, mmu_kernel_ssize); 238 if (rc < 0) { 239 int rc2 = htab_remove_mapping(start, start + page_size, 240 mmu_vmemmap_psize, 241 mmu_kernel_ssize); 242 BUG_ON(rc2 && (rc2 != -ENOENT)); 243 } 244 return rc; 245 } 246 247 #ifdef CONFIG_MEMORY_HOTPLUG 248 static void vmemmap_remove_mapping(unsigned long start, 249 unsigned long page_size) 250 { 251 int rc = htab_remove_mapping(start, start + page_size, 252 mmu_vmemmap_psize, 253 mmu_kernel_ssize); 254 BUG_ON((rc < 0) && (rc != -ENOENT)); 255 WARN_ON(rc == -ENOENT); 256 } 257 #endif 258 259 #endif /* CONFIG_PPC_BOOK3E */ 260 261 struct vmemmap_backing *vmemmap_list; 262 static struct vmemmap_backing *next; 263 static int num_left; 264 static int num_freed; 265 266 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 267 { 268 struct vmemmap_backing *vmem_back; 269 /* get from freed entries first */ 270 if (num_freed) { 271 num_freed--; 272 vmem_back = next; 273 next = next->list; 274 275 return vmem_back; 276 } 277 278 /* allocate a page when required and hand out chunks */ 279 if (!num_left) { 280 next = vmemmap_alloc_block(PAGE_SIZE, node); 281 if (unlikely(!next)) { 282 WARN_ON(1); 283 return NULL; 284 } 285 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 286 } 287 288 num_left--; 289 290 return next++; 291 } 292 293 static __meminit void vmemmap_list_populate(unsigned long phys, 294 unsigned long start, 295 int node) 296 { 297 struct vmemmap_backing *vmem_back; 298 299 vmem_back = vmemmap_list_alloc(node); 300 if (unlikely(!vmem_back)) { 301 WARN_ON(1); 302 return; 303 } 304 305 vmem_back->phys = phys; 306 vmem_back->virt_addr = start; 307 vmem_back->list = vmemmap_list; 308 309 vmemmap_list = vmem_back; 310 } 311 312 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 313 { 314 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 315 316 /* Align to the page size of the linear mapping. */ 317 start = _ALIGN_DOWN(start, page_size); 318 319 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 320 321 for (; start < end; start += page_size) { 322 void *p; 323 int rc; 324 325 if (vmemmap_populated(start, page_size)) 326 continue; 327 328 p = vmemmap_alloc_block(page_size, node); 329 if (!p) 330 return -ENOMEM; 331 332 vmemmap_list_populate(__pa(p), start, node); 333 334 pr_debug(" * %016lx..%016lx allocated at %p\n", 335 start, start + page_size, p); 336 337 rc = vmemmap_create_mapping(start, page_size, __pa(p)); 338 if (rc < 0) { 339 pr_warning( 340 "vmemmap_populate: Unable to create vmemmap mapping: %d\n", 341 rc); 342 return -EFAULT; 343 } 344 } 345 346 return 0; 347 } 348 349 #ifdef CONFIG_MEMORY_HOTPLUG 350 static unsigned long vmemmap_list_free(unsigned long start) 351 { 352 struct vmemmap_backing *vmem_back, *vmem_back_prev; 353 354 vmem_back_prev = vmem_back = vmemmap_list; 355 356 /* look for it with prev pointer recorded */ 357 for (; vmem_back; vmem_back = vmem_back->list) { 358 if (vmem_back->virt_addr == start) 359 break; 360 vmem_back_prev = vmem_back; 361 } 362 363 if (unlikely(!vmem_back)) { 364 WARN_ON(1); 365 return 0; 366 } 367 368 /* remove it from vmemmap_list */ 369 if (vmem_back == vmemmap_list) /* remove head */ 370 vmemmap_list = vmem_back->list; 371 else 372 vmem_back_prev->list = vmem_back->list; 373 374 /* next point to this freed entry */ 375 vmem_back->list = next; 376 next = vmem_back; 377 num_freed++; 378 379 return vmem_back->phys; 380 } 381 382 void __ref vmemmap_free(unsigned long start, unsigned long end) 383 { 384 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 385 386 start = _ALIGN_DOWN(start, page_size); 387 388 pr_debug("vmemmap_free %lx...%lx\n", start, end); 389 390 for (; start < end; start += page_size) { 391 unsigned long addr; 392 393 /* 394 * the section has already be marked as invalid, so 395 * vmemmap_populated() true means some other sections still 396 * in this page, so skip it. 397 */ 398 if (vmemmap_populated(start, page_size)) 399 continue; 400 401 addr = vmemmap_list_free(start); 402 if (addr) { 403 struct page *page = pfn_to_page(addr >> PAGE_SHIFT); 404 405 if (PageReserved(page)) { 406 /* allocated from bootmem */ 407 if (page_size < PAGE_SIZE) { 408 /* 409 * this shouldn't happen, but if it is 410 * the case, leave the memory there 411 */ 412 WARN_ON_ONCE(1); 413 } else { 414 unsigned int nr_pages = 415 1 << get_order(page_size); 416 while (nr_pages--) 417 free_reserved_page(page++); 418 } 419 } else 420 free_pages((unsigned long)(__va(addr)), 421 get_order(page_size)); 422 423 vmemmap_remove_mapping(start, page_size); 424 } 425 } 426 } 427 #endif 428 void register_page_bootmem_memmap(unsigned long section_nr, 429 struct page *start_page, unsigned long size) 430 { 431 } 432 433 /* 434 * We do not have access to the sparsemem vmemmap, so we fallback to 435 * walking the list of sparsemem blocks which we already maintain for 436 * the sake of crashdump. In the long run, we might want to maintain 437 * a tree if performance of that linear walk becomes a problem. 438 * 439 * realmode_pfn_to_page functions can fail due to: 440 * 1) As real sparsemem blocks do not lay in RAM continously (they 441 * are in virtual address space which is not available in the real mode), 442 * the requested page struct can be split between blocks so get_page/put_page 443 * may fail. 444 * 2) When huge pages are used, the get_page/put_page API will fail 445 * in real mode as the linked addresses in the page struct are virtual 446 * too. 447 */ 448 struct page *realmode_pfn_to_page(unsigned long pfn) 449 { 450 struct vmemmap_backing *vmem_back; 451 struct page *page; 452 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 453 unsigned long pg_va = (unsigned long) pfn_to_page(pfn); 454 455 for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) { 456 if (pg_va < vmem_back->virt_addr) 457 continue; 458 459 /* After vmemmap_list entry free is possible, need check all */ 460 if ((pg_va + sizeof(struct page)) <= 461 (vmem_back->virt_addr + page_size)) { 462 page = (struct page *) (vmem_back->phys + pg_va - 463 vmem_back->virt_addr); 464 return page; 465 } 466 } 467 468 /* Probably that page struct is split between real pages */ 469 return NULL; 470 } 471 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 472 473 #elif defined(CONFIG_FLATMEM) 474 475 struct page *realmode_pfn_to_page(unsigned long pfn) 476 { 477 struct page *page = pfn_to_page(pfn); 478 return page; 479 } 480 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 481 482 #endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */ 483