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 #include <linux/of_fdt.h> 46 #include <linux/libfdt.h> 47 48 #include <asm/pgalloc.h> 49 #include <asm/page.h> 50 #include <asm/prom.h> 51 #include <asm/rtas.h> 52 #include <asm/io.h> 53 #include <asm/mmu_context.h> 54 #include <asm/pgtable.h> 55 #include <asm/mmu.h> 56 #include <linux/uaccess.h> 57 #include <asm/smp.h> 58 #include <asm/machdep.h> 59 #include <asm/tlb.h> 60 #include <asm/eeh.h> 61 #include <asm/processor.h> 62 #include <asm/mmzone.h> 63 #include <asm/cputable.h> 64 #include <asm/sections.h> 65 #include <asm/iommu.h> 66 #include <asm/vdso.h> 67 68 #include "mmu_decl.h" 69 70 #ifdef CONFIG_PPC_STD_MMU_64 71 #if H_PGTABLE_RANGE > USER_VSID_RANGE 72 #warning Limited user VSID range means pagetable space is wasted 73 #endif 74 75 #if (TASK_SIZE_USER64 < H_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 EXPORT_SYMBOL_GPL(memstart_addr); 82 phys_addr_t kernstart_addr; 83 EXPORT_SYMBOL_GPL(kernstart_addr); 84 85 #ifdef CONFIG_SPARSEMEM_VMEMMAP 86 /* 87 * Given an address within the vmemmap, determine the pfn of the page that 88 * represents the start of the section it is within. Note that we have to 89 * do this by hand as the proffered address may not be correctly aligned. 90 * Subtraction of non-aligned pointers produces undefined results. 91 */ 92 static unsigned long __meminit vmemmap_section_start(unsigned long page) 93 { 94 unsigned long offset = page - ((unsigned long)(vmemmap)); 95 96 /* Return the pfn of the start of the section. */ 97 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 98 } 99 100 /* 101 * Check if this vmemmap page is already initialised. If any section 102 * which overlaps this vmemmap page is initialised then this page is 103 * initialised already. 104 */ 105 static int __meminit vmemmap_populated(unsigned long start, int page_size) 106 { 107 unsigned long end = start + page_size; 108 start = (unsigned long)(pfn_to_page(vmemmap_section_start(start))); 109 110 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 111 if (pfn_valid(page_to_pfn((struct page *)start))) 112 return 1; 113 114 return 0; 115 } 116 117 struct vmemmap_backing *vmemmap_list; 118 static struct vmemmap_backing *next; 119 static int num_left; 120 static int num_freed; 121 122 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 123 { 124 struct vmemmap_backing *vmem_back; 125 /* get from freed entries first */ 126 if (num_freed) { 127 num_freed--; 128 vmem_back = next; 129 next = next->list; 130 131 return vmem_back; 132 } 133 134 /* allocate a page when required and hand out chunks */ 135 if (!num_left) { 136 next = vmemmap_alloc_block(PAGE_SIZE, node); 137 if (unlikely(!next)) { 138 WARN_ON(1); 139 return NULL; 140 } 141 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 142 } 143 144 num_left--; 145 146 return next++; 147 } 148 149 static __meminit void vmemmap_list_populate(unsigned long phys, 150 unsigned long start, 151 int node) 152 { 153 struct vmemmap_backing *vmem_back; 154 155 vmem_back = vmemmap_list_alloc(node); 156 if (unlikely(!vmem_back)) { 157 WARN_ON(1); 158 return; 159 } 160 161 vmem_back->phys = phys; 162 vmem_back->virt_addr = start; 163 vmem_back->list = vmemmap_list; 164 165 vmemmap_list = vmem_back; 166 } 167 168 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 169 { 170 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 171 172 /* Align to the page size of the linear mapping. */ 173 start = _ALIGN_DOWN(start, page_size); 174 175 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 176 177 for (; start < end; start += page_size) { 178 void *p; 179 int rc; 180 181 if (vmemmap_populated(start, page_size)) 182 continue; 183 184 p = vmemmap_alloc_block(page_size, node); 185 if (!p) 186 return -ENOMEM; 187 188 vmemmap_list_populate(__pa(p), start, node); 189 190 pr_debug(" * %016lx..%016lx allocated at %p\n", 191 start, start + page_size, p); 192 193 rc = vmemmap_create_mapping(start, page_size, __pa(p)); 194 if (rc < 0) { 195 pr_warning( 196 "vmemmap_populate: Unable to create vmemmap mapping: %d\n", 197 rc); 198 return -EFAULT; 199 } 200 } 201 202 return 0; 203 } 204 205 #ifdef CONFIG_MEMORY_HOTPLUG 206 static unsigned long vmemmap_list_free(unsigned long start) 207 { 208 struct vmemmap_backing *vmem_back, *vmem_back_prev; 209 210 vmem_back_prev = vmem_back = vmemmap_list; 211 212 /* look for it with prev pointer recorded */ 213 for (; vmem_back; vmem_back = vmem_back->list) { 214 if (vmem_back->virt_addr == start) 215 break; 216 vmem_back_prev = vmem_back; 217 } 218 219 if (unlikely(!vmem_back)) { 220 WARN_ON(1); 221 return 0; 222 } 223 224 /* remove it from vmemmap_list */ 225 if (vmem_back == vmemmap_list) /* remove head */ 226 vmemmap_list = vmem_back->list; 227 else 228 vmem_back_prev->list = vmem_back->list; 229 230 /* next point to this freed entry */ 231 vmem_back->list = next; 232 next = vmem_back; 233 num_freed++; 234 235 return vmem_back->phys; 236 } 237 238 void __ref vmemmap_free(unsigned long start, unsigned long end) 239 { 240 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 241 242 start = _ALIGN_DOWN(start, page_size); 243 244 pr_debug("vmemmap_free %lx...%lx\n", start, end); 245 246 for (; start < end; start += page_size) { 247 unsigned long addr; 248 249 /* 250 * the section has already be marked as invalid, so 251 * vmemmap_populated() true means some other sections still 252 * in this page, so skip it. 253 */ 254 if (vmemmap_populated(start, page_size)) 255 continue; 256 257 addr = vmemmap_list_free(start); 258 if (addr) { 259 struct page *page = pfn_to_page(addr >> PAGE_SHIFT); 260 261 if (PageReserved(page)) { 262 /* allocated from bootmem */ 263 if (page_size < PAGE_SIZE) { 264 /* 265 * this shouldn't happen, but if it is 266 * the case, leave the memory there 267 */ 268 WARN_ON_ONCE(1); 269 } else { 270 unsigned int nr_pages = 271 1 << get_order(page_size); 272 while (nr_pages--) 273 free_reserved_page(page++); 274 } 275 } else 276 free_pages((unsigned long)(__va(addr)), 277 get_order(page_size)); 278 279 vmemmap_remove_mapping(start, page_size); 280 } 281 } 282 } 283 #endif 284 void register_page_bootmem_memmap(unsigned long section_nr, 285 struct page *start_page, unsigned long size) 286 { 287 } 288 289 /* 290 * We do not have access to the sparsemem vmemmap, so we fallback to 291 * walking the list of sparsemem blocks which we already maintain for 292 * the sake of crashdump. In the long run, we might want to maintain 293 * a tree if performance of that linear walk becomes a problem. 294 * 295 * realmode_pfn_to_page functions can fail due to: 296 * 1) As real sparsemem blocks do not lay in RAM continously (they 297 * are in virtual address space which is not available in the real mode), 298 * the requested page struct can be split between blocks so get_page/put_page 299 * may fail. 300 * 2) When huge pages are used, the get_page/put_page API will fail 301 * in real mode as the linked addresses in the page struct are virtual 302 * too. 303 */ 304 struct page *realmode_pfn_to_page(unsigned long pfn) 305 { 306 struct vmemmap_backing *vmem_back; 307 struct page *page; 308 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 309 unsigned long pg_va = (unsigned long) pfn_to_page(pfn); 310 311 for (vmem_back = vmemmap_list; vmem_back; vmem_back = vmem_back->list) { 312 if (pg_va < vmem_back->virt_addr) 313 continue; 314 315 /* After vmemmap_list entry free is possible, need check all */ 316 if ((pg_va + sizeof(struct page)) <= 317 (vmem_back->virt_addr + page_size)) { 318 page = (struct page *) (vmem_back->phys + pg_va - 319 vmem_back->virt_addr); 320 return page; 321 } 322 } 323 324 /* Probably that page struct is split between real pages */ 325 return NULL; 326 } 327 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 328 329 #elif defined(CONFIG_FLATMEM) 330 331 struct page *realmode_pfn_to_page(unsigned long pfn) 332 { 333 struct page *page = pfn_to_page(pfn); 334 return page; 335 } 336 EXPORT_SYMBOL_GPL(realmode_pfn_to_page); 337 338 #endif /* CONFIG_SPARSEMEM_VMEMMAP/CONFIG_FLATMEM */ 339 340 #ifdef CONFIG_PPC_STD_MMU_64 341 static bool disable_radix; 342 static int __init parse_disable_radix(char *p) 343 { 344 disable_radix = true; 345 return 0; 346 } 347 early_param("disable_radix", parse_disable_radix); 348 349 /* 350 * If we're running under a hypervisor, we need to check the contents of 351 * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do 352 * radix. If not, we clear the radix feature bit so we fall back to hash. 353 */ 354 static void early_check_vec5(void) 355 { 356 unsigned long root, chosen; 357 int size; 358 const u8 *vec5; 359 u8 mmu_supported; 360 361 root = of_get_flat_dt_root(); 362 chosen = of_get_flat_dt_subnode_by_name(root, "chosen"); 363 if (chosen == -FDT_ERR_NOTFOUND) { 364 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 365 return; 366 } 367 vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size); 368 if (!vec5) { 369 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 370 return; 371 } 372 if (size <= OV5_INDX(OV5_MMU_SUPPORT)) { 373 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 374 return; 375 } 376 377 /* Check for supported configuration */ 378 mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] & 379 OV5_FEAT(OV5_MMU_SUPPORT); 380 if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) { 381 /* Hypervisor only supports radix - check enabled && GTSE */ 382 if (!early_radix_enabled()) { 383 pr_warn("WARNING: Ignoring cmdline option disable_radix\n"); 384 } 385 if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] & 386 OV5_FEAT(OV5_RADIX_GTSE))) { 387 pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n"); 388 } 389 /* Do radix anyway - the hypervisor said we had to */ 390 cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX; 391 } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) { 392 /* Hypervisor only supports hash - disable radix */ 393 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 394 } 395 } 396 397 void __init mmu_early_init_devtree(void) 398 { 399 /* Disable radix mode based on kernel command line. */ 400 if (disable_radix) 401 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 402 403 /* 404 * Check /chosen/ibm,architecture-vec-5 if running as a guest. 405 * When running bare-metal, we can use radix if we like 406 * even though the ibm,architecture-vec-5 property created by 407 * skiboot doesn't have the necessary bits set. 408 */ 409 if (!(mfmsr() & MSR_HV)) 410 early_check_vec5(); 411 412 if (early_radix_enabled()) 413 radix__early_init_devtree(); 414 else 415 hash__early_init_devtree(); 416 } 417 #endif /* CONFIG_PPC_STD_MMU_64 */ 418