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 #ifdef CONFIG_SPARSEMEM_VMEMMAP 84 /* 85 * Given an address within the vmemmap, determine the pfn of the page that 86 * represents the start of the section it is within. Note that we have to 87 * do this by hand as the proffered address may not be correctly aligned. 88 * Subtraction of non-aligned pointers produces undefined results. 89 */ 90 static unsigned long __meminit vmemmap_section_start(unsigned long page) 91 { 92 unsigned long offset = page - ((unsigned long)(vmemmap)); 93 94 /* Return the pfn of the start of the section. */ 95 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 96 } 97 98 /* 99 * Check if this vmemmap page is already initialised. If any section 100 * which overlaps this vmemmap page is initialised then this page is 101 * initialised already. 102 */ 103 static int __meminit vmemmap_populated(unsigned long start, int page_size) 104 { 105 unsigned long end = start + page_size; 106 start = (unsigned long)(pfn_to_page(vmemmap_section_start(start))); 107 108 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 109 if (pfn_valid(page_to_pfn((struct page *)start))) 110 return 1; 111 112 return 0; 113 } 114 115 struct vmemmap_backing *vmemmap_list; 116 static struct vmemmap_backing *next; 117 static int num_left; 118 static int num_freed; 119 120 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 121 { 122 struct vmemmap_backing *vmem_back; 123 /* get from freed entries first */ 124 if (num_freed) { 125 num_freed--; 126 vmem_back = next; 127 next = next->list; 128 129 return vmem_back; 130 } 131 132 /* allocate a page when required and hand out chunks */ 133 if (!num_left) { 134 next = vmemmap_alloc_block(PAGE_SIZE, node); 135 if (unlikely(!next)) { 136 WARN_ON(1); 137 return NULL; 138 } 139 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 140 } 141 142 num_left--; 143 144 return next++; 145 } 146 147 static __meminit void vmemmap_list_populate(unsigned long phys, 148 unsigned long start, 149 int node) 150 { 151 struct vmemmap_backing *vmem_back; 152 153 vmem_back = vmemmap_list_alloc(node); 154 if (unlikely(!vmem_back)) { 155 WARN_ON(1); 156 return; 157 } 158 159 vmem_back->phys = phys; 160 vmem_back->virt_addr = start; 161 vmem_back->list = vmemmap_list; 162 163 vmemmap_list = vmem_back; 164 } 165 166 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 167 { 168 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 169 170 /* Align to the page size of the linear mapping. */ 171 start = _ALIGN_DOWN(start, page_size); 172 173 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 174 175 for (; start < end; start += page_size) { 176 void *p; 177 int rc; 178 179 if (vmemmap_populated(start, page_size)) 180 continue; 181 182 p = vmemmap_alloc_block(page_size, node); 183 if (!p) 184 return -ENOMEM; 185 186 vmemmap_list_populate(__pa(p), start, node); 187 188 pr_debug(" * %016lx..%016lx allocated at %p\n", 189 start, start + page_size, p); 190 191 rc = vmemmap_create_mapping(start, page_size, __pa(p)); 192 if (rc < 0) { 193 pr_warning( 194 "vmemmap_populate: Unable to create vmemmap mapping: %d\n", 195 rc); 196 return -EFAULT; 197 } 198 } 199 200 return 0; 201 } 202 203 #ifdef CONFIG_MEMORY_HOTPLUG 204 static unsigned long vmemmap_list_free(unsigned long start) 205 { 206 struct vmemmap_backing *vmem_back, *vmem_back_prev; 207 208 vmem_back_prev = vmem_back = vmemmap_list; 209 210 /* look for it with prev pointer recorded */ 211 for (; vmem_back; vmem_back = vmem_back->list) { 212 if (vmem_back->virt_addr == start) 213 break; 214 vmem_back_prev = vmem_back; 215 } 216 217 if (unlikely(!vmem_back)) { 218 WARN_ON(1); 219 return 0; 220 } 221 222 /* remove it from vmemmap_list */ 223 if (vmem_back == vmemmap_list) /* remove head */ 224 vmemmap_list = vmem_back->list; 225 else 226 vmem_back_prev->list = vmem_back->list; 227 228 /* next point to this freed entry */ 229 vmem_back->list = next; 230 next = vmem_back; 231 num_freed++; 232 233 return vmem_back->phys; 234 } 235 236 void __ref vmemmap_free(unsigned long start, unsigned long end) 237 { 238 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 239 240 start = _ALIGN_DOWN(start, page_size); 241 242 pr_debug("vmemmap_free %lx...%lx\n", start, end); 243 244 for (; start < end; start += page_size) { 245 unsigned long addr; 246 247 /* 248 * the section has already be marked as invalid, so 249 * vmemmap_populated() true means some other sections still 250 * in this page, so skip it. 251 */ 252 if (vmemmap_populated(start, page_size)) 253 continue; 254 255 addr = vmemmap_list_free(start); 256 if (addr) { 257 struct page *page = pfn_to_page(addr >> PAGE_SHIFT); 258 259 if (PageReserved(page)) { 260 /* allocated from bootmem */ 261 if (page_size < PAGE_SIZE) { 262 /* 263 * this shouldn't happen, but if it is 264 * the case, leave the memory there 265 */ 266 WARN_ON_ONCE(1); 267 } else { 268 unsigned int nr_pages = 269 1 << get_order(page_size); 270 while (nr_pages--) 271 free_reserved_page(page++); 272 } 273 } else 274 free_pages((unsigned long)(__va(addr)), 275 get_order(page_size)); 276 277 vmemmap_remove_mapping(start, page_size); 278 } 279 } 280 } 281 #endif 282 void register_page_bootmem_memmap(unsigned long section_nr, 283 struct page *start_page, unsigned long size) 284 { 285 } 286 287 /* 288 * We do not have access to the sparsemem vmemmap, so we fallback to 289 * walking the list of sparsemem blocks which we already maintain for 290 * the sake of crashdump. In the long run, we might want to maintain 291 * a tree if performance of that linear walk becomes a problem. 292 * 293 * realmode_pfn_to_page functions can fail due to: 294 * 1) As real sparsemem blocks do not lay in RAM continously (they 295 * are in virtual address space which is not available in the real mode), 296 * the requested page struct can be split between blocks so get_page/put_page 297 * may fail. 298 * 2) When huge pages are used, the get_page/put_page API will fail 299 * in real mode as the linked addresses in the page struct are virtual 300 * too. 301 */ 302 struct page *realmode_pfn_to_page(unsigned long pfn) 303 { 304 struct vmemmap_backing *vmem_back; 305 struct page *page; 306 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 307 unsigned long pg_va = (unsigned long) pfn_to_page(pfn); 308 309 for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) { 310 if (pg_va < vmem_back->virt_addr) 311 continue; 312 313 /* After vmemmap_list entry free is possible, need check all */ 314 if ((pg_va + sizeof(struct page)) <= 315 (vmem_back->virt_addr + page_size)) { 316 page = (struct page *) (vmem_back->phys + pg_va - 317 vmem_back->virt_addr); 318 return page; 319 } 320 } 321 322 /* Probably that page struct is split between real pages */ 323 return NULL; 324 } 325 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 326 327 #elif defined(CONFIG_FLATMEM) 328 329 struct page *realmode_pfn_to_page(unsigned long pfn) 330 { 331 struct page *page = pfn_to_page(pfn); 332 return page; 333 } 334 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 335 336 #endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */ 337 338 #ifdef CONFIG_PPC_STD_MMU_64 339 static bool disable_radix; 340 static int __init parse_disable_radix(char *p) 341 { 342 disable_radix = true; 343 return 0; 344 } 345 early_param("disable_radix", parse_disable_radix); 346 347 void __init mmu_early_init_devtree(void) 348 { 349 /* Disable radix mode based on kernel command line. */ 350 if (disable_radix) 351 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 352 353 if (early_radix_enabled()) 354 radix__early_init_devtree(); 355 else 356 hash__early_init_devtree(); 357 } 358 #endif /* CONFIG_PPC_STD_MMU_64 */ 359