1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * PowerPC version 4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 5 * 6 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) 7 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 8 * Copyright (C) 1996 Paul Mackerras 9 * 10 * Derived from "arch/i386/mm/init.c" 11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 12 * 13 * Dave Engebretsen <engebret@us.ibm.com> 14 * Rework for PPC64 port. 15 */ 16 17 #undef DEBUG 18 19 #include <linux/signal.h> 20 #include <linux/sched.h> 21 #include <linux/kernel.h> 22 #include <linux/errno.h> 23 #include <linux/string.h> 24 #include <linux/types.h> 25 #include <linux/mman.h> 26 #include <linux/mm.h> 27 #include <linux/swap.h> 28 #include <linux/stddef.h> 29 #include <linux/vmalloc.h> 30 #include <linux/init.h> 31 #include <linux/delay.h> 32 #include <linux/highmem.h> 33 #include <linux/idr.h> 34 #include <linux/nodemask.h> 35 #include <linux/module.h> 36 #include <linux/poison.h> 37 #include <linux/memblock.h> 38 #include <linux/hugetlb.h> 39 #include <linux/slab.h> 40 #include <linux/of_fdt.h> 41 #include <linux/libfdt.h> 42 #include <linux/memremap.h> 43 44 #include <asm/pgalloc.h> 45 #include <asm/page.h> 46 #include <asm/prom.h> 47 #include <asm/rtas.h> 48 #include <asm/io.h> 49 #include <asm/mmu_context.h> 50 #include <asm/pgtable.h> 51 #include <asm/mmu.h> 52 #include <linux/uaccess.h> 53 #include <asm/smp.h> 54 #include <asm/machdep.h> 55 #include <asm/tlb.h> 56 #include <asm/eeh.h> 57 #include <asm/processor.h> 58 #include <asm/mmzone.h> 59 #include <asm/cputable.h> 60 #include <asm/sections.h> 61 #include <asm/iommu.h> 62 #include <asm/vdso.h> 63 64 #include <mm/mmu_decl.h> 65 66 phys_addr_t memstart_addr = ~0; 67 EXPORT_SYMBOL_GPL(memstart_addr); 68 phys_addr_t kernstart_addr; 69 EXPORT_SYMBOL_GPL(kernstart_addr); 70 71 #ifdef CONFIG_SPARSEMEM_VMEMMAP 72 /* 73 * Given an address within the vmemmap, determine the pfn of the page that 74 * represents the start of the section it is within. Note that we have to 75 * do this by hand as the proffered address may not be correctly aligned. 76 * Subtraction of non-aligned pointers produces undefined results. 77 */ 78 static unsigned long __meminit vmemmap_section_start(unsigned long page) 79 { 80 unsigned long offset = page - ((unsigned long)(vmemmap)); 81 82 /* Return the pfn of the start of the section. */ 83 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; 84 } 85 86 /* 87 * Check if this vmemmap page is already initialised. If any section 88 * which overlaps this vmemmap page is initialised then this page is 89 * initialised already. 90 */ 91 static int __meminit vmemmap_populated(unsigned long start, int page_size) 92 { 93 unsigned long end = start + page_size; 94 start = (unsigned long)(pfn_to_page(vmemmap_section_start(start))); 95 96 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) 97 if (pfn_valid(page_to_pfn((struct page *)start))) 98 return 1; 99 100 return 0; 101 } 102 103 /* 104 * vmemmap virtual address space management does not have a traditonal page 105 * table to track which virtual struct pages are backed by physical mapping. 106 * The virtual to physical mappings are tracked in a simple linked list 107 * format. 'vmemmap_list' maintains the entire vmemmap physical mapping at 108 * all times where as the 'next' list maintains the available 109 * vmemmap_backing structures which have been deleted from the 110 * 'vmemmap_global' list during system runtime (memory hotplug remove 111 * operation). The freed 'vmemmap_backing' structures are reused later when 112 * new requests come in without allocating fresh memory. This pointer also 113 * tracks the allocated 'vmemmap_backing' structures as we allocate one 114 * full page memory at a time when we dont have any. 115 */ 116 struct vmemmap_backing *vmemmap_list; 117 static struct vmemmap_backing *next; 118 119 /* 120 * The same pointer 'next' tracks individual chunks inside the allocated 121 * full page during the boot time and again tracks the freeed nodes during 122 * runtime. It is racy but it does not happen as they are separated by the 123 * boot process. Will create problem if some how we have memory hotplug 124 * operation during boot !! 125 */ 126 static int num_left; 127 static int num_freed; 128 129 static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) 130 { 131 struct vmemmap_backing *vmem_back; 132 /* get from freed entries first */ 133 if (num_freed) { 134 num_freed--; 135 vmem_back = next; 136 next = next->list; 137 138 return vmem_back; 139 } 140 141 /* allocate a page when required and hand out chunks */ 142 if (!num_left) { 143 next = vmemmap_alloc_block(PAGE_SIZE, node); 144 if (unlikely(!next)) { 145 WARN_ON(1); 146 return NULL; 147 } 148 num_left = PAGE_SIZE / sizeof(struct vmemmap_backing); 149 } 150 151 num_left--; 152 153 return next++; 154 } 155 156 static __meminit void vmemmap_list_populate(unsigned long phys, 157 unsigned long start, 158 int node) 159 { 160 struct vmemmap_backing *vmem_back; 161 162 vmem_back = vmemmap_list_alloc(node); 163 if (unlikely(!vmem_back)) { 164 WARN_ON(1); 165 return; 166 } 167 168 vmem_back->phys = phys; 169 vmem_back->virt_addr = start; 170 vmem_back->list = vmemmap_list; 171 172 vmemmap_list = vmem_back; 173 } 174 175 static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start, 176 unsigned long page_size) 177 { 178 unsigned long nr_pfn = page_size / sizeof(struct page); 179 unsigned long start_pfn = page_to_pfn((struct page *)start); 180 181 if ((start_pfn + nr_pfn) > altmap->end_pfn) 182 return true; 183 184 if (start_pfn < altmap->base_pfn) 185 return true; 186 187 return false; 188 } 189 190 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 191 struct vmem_altmap *altmap) 192 { 193 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 194 195 /* Align to the page size of the linear mapping. */ 196 start = _ALIGN_DOWN(start, page_size); 197 198 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 199 200 for (; start < end; start += page_size) { 201 void *p = NULL; 202 int rc; 203 204 if (vmemmap_populated(start, page_size)) 205 continue; 206 207 /* 208 * Allocate from the altmap first if we have one. This may 209 * fail due to alignment issues when using 16MB hugepages, so 210 * fall back to system memory if the altmap allocation fail. 211 */ 212 if (altmap && !altmap_cross_boundary(altmap, start, page_size)) { 213 p = altmap_alloc_block_buf(page_size, altmap); 214 if (!p) 215 pr_debug("altmap block allocation failed, falling back to system memory"); 216 } 217 if (!p) 218 p = vmemmap_alloc_block_buf(page_size, node); 219 if (!p) 220 return -ENOMEM; 221 222 vmemmap_list_populate(__pa(p), start, node); 223 224 pr_debug(" * %016lx..%016lx allocated at %p\n", 225 start, start + page_size, p); 226 227 rc = vmemmap_create_mapping(start, page_size, __pa(p)); 228 if (rc < 0) { 229 pr_warn("%s: Unable to create vmemmap mapping: %d\n", 230 __func__, rc); 231 return -EFAULT; 232 } 233 } 234 235 return 0; 236 } 237 238 #ifdef CONFIG_MEMORY_HOTPLUG 239 static unsigned long vmemmap_list_free(unsigned long start) 240 { 241 struct vmemmap_backing *vmem_back, *vmem_back_prev; 242 243 vmem_back_prev = vmem_back = vmemmap_list; 244 245 /* look for it with prev pointer recorded */ 246 for (; vmem_back; vmem_back = vmem_back->list) { 247 if (vmem_back->virt_addr == start) 248 break; 249 vmem_back_prev = vmem_back; 250 } 251 252 if (unlikely(!vmem_back)) { 253 WARN_ON(1); 254 return 0; 255 } 256 257 /* remove it from vmemmap_list */ 258 if (vmem_back == vmemmap_list) /* remove head */ 259 vmemmap_list = vmem_back->list; 260 else 261 vmem_back_prev->list = vmem_back->list; 262 263 /* next point to this freed entry */ 264 vmem_back->list = next; 265 next = vmem_back; 266 num_freed++; 267 268 return vmem_back->phys; 269 } 270 271 void __ref vmemmap_free(unsigned long start, unsigned long end, 272 struct vmem_altmap *altmap) 273 { 274 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 275 unsigned long page_order = get_order(page_size); 276 unsigned long alt_start = ~0, alt_end = ~0; 277 unsigned long base_pfn; 278 279 start = _ALIGN_DOWN(start, page_size); 280 if (altmap) { 281 alt_start = altmap->base_pfn; 282 alt_end = altmap->base_pfn + altmap->reserve + 283 altmap->free + altmap->alloc + altmap->align; 284 } 285 286 pr_debug("vmemmap_free %lx...%lx\n", start, end); 287 288 for (; start < end; start += page_size) { 289 unsigned long nr_pages, addr; 290 struct page *page; 291 292 /* 293 * the section has already be marked as invalid, so 294 * vmemmap_populated() true means some other sections still 295 * in this page, so skip it. 296 */ 297 if (vmemmap_populated(start, page_size)) 298 continue; 299 300 addr = vmemmap_list_free(start); 301 if (!addr) 302 continue; 303 304 page = pfn_to_page(addr >> PAGE_SHIFT); 305 nr_pages = 1 << page_order; 306 base_pfn = PHYS_PFN(addr); 307 308 if (base_pfn >= alt_start && base_pfn < alt_end) { 309 vmem_altmap_free(altmap, nr_pages); 310 } else if (PageReserved(page)) { 311 /* allocated from bootmem */ 312 if (page_size < PAGE_SIZE) { 313 /* 314 * this shouldn't happen, but if it is 315 * the case, leave the memory there 316 */ 317 WARN_ON_ONCE(1); 318 } else { 319 while (nr_pages--) 320 free_reserved_page(page++); 321 } 322 } else { 323 free_pages((unsigned long)(__va(addr)), page_order); 324 } 325 326 vmemmap_remove_mapping(start, page_size); 327 } 328 } 329 #endif 330 void register_page_bootmem_memmap(unsigned long section_nr, 331 struct page *start_page, unsigned long size) 332 { 333 } 334 335 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 336 337 #ifdef CONFIG_PPC_BOOK3S_64 338 static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT); 339 340 static int __init parse_disable_radix(char *p) 341 { 342 bool val; 343 344 if (!p) 345 val = true; 346 else if (kstrtobool(p, &val)) 347 return -EINVAL; 348 349 disable_radix = val; 350 351 return 0; 352 } 353 early_param("disable_radix", parse_disable_radix); 354 355 /* 356 * If we're running under a hypervisor, we need to check the contents of 357 * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do 358 * radix. If not, we clear the radix feature bit so we fall back to hash. 359 */ 360 static void __init early_check_vec5(void) 361 { 362 unsigned long root, chosen; 363 int size; 364 const u8 *vec5; 365 u8 mmu_supported; 366 367 root = of_get_flat_dt_root(); 368 chosen = of_get_flat_dt_subnode_by_name(root, "chosen"); 369 if (chosen == -FDT_ERR_NOTFOUND) { 370 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 371 return; 372 } 373 vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size); 374 if (!vec5) { 375 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 376 return; 377 } 378 if (size <= OV5_INDX(OV5_MMU_SUPPORT)) { 379 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 380 return; 381 } 382 383 /* Check for supported configuration */ 384 mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] & 385 OV5_FEAT(OV5_MMU_SUPPORT); 386 if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) { 387 /* Hypervisor only supports radix - check enabled && GTSE */ 388 if (!early_radix_enabled()) { 389 pr_warn("WARNING: Ignoring cmdline option disable_radix\n"); 390 } 391 if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] & 392 OV5_FEAT(OV5_RADIX_GTSE))) { 393 pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n"); 394 } 395 /* Do radix anyway - the hypervisor said we had to */ 396 cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX; 397 } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) { 398 /* Hypervisor only supports hash - disable radix */ 399 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 400 } 401 } 402 403 void __init mmu_early_init_devtree(void) 404 { 405 /* Disable radix mode based on kernel command line. */ 406 if (disable_radix) 407 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 408 409 /* 410 * Check /chosen/ibm,architecture-vec-5 if running as a guest. 411 * When running bare-metal, we can use radix if we like 412 * even though the ibm,architecture-vec-5 property created by 413 * skiboot doesn't have the necessary bits set. 414 */ 415 if (!(mfmsr() & MSR_HV)) 416 early_check_vec5(); 417 418 if (early_radix_enabled()) 419 radix__early_init_devtree(); 420 else 421 hash__early_init_devtree(); 422 } 423 #endif /* CONFIG_PPC_BOOK3S_64 */ 424