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 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 176 struct vmem_altmap *altmap) 177 { 178 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 179 180 /* Align to the page size of the linear mapping. */ 181 start = _ALIGN_DOWN(start, page_size); 182 183 pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node); 184 185 for (; start < end; start += page_size) { 186 void *p = NULL; 187 int rc; 188 189 if (vmemmap_populated(start, page_size)) 190 continue; 191 192 /* 193 * Allocate from the altmap first if we have one. This may 194 * fail due to alignment issues when using 16MB hugepages, so 195 * fall back to system memory if the altmap allocation fail. 196 */ 197 if (altmap) { 198 p = altmap_alloc_block_buf(page_size, altmap); 199 if (!p) 200 pr_debug("altmap block allocation failed, falling back to system memory"); 201 } 202 if (!p) 203 p = vmemmap_alloc_block_buf(page_size, node); 204 if (!p) 205 return -ENOMEM; 206 207 vmemmap_list_populate(__pa(p), start, node); 208 209 pr_debug(" * %016lx..%016lx allocated at %p\n", 210 start, start + page_size, p); 211 212 rc = vmemmap_create_mapping(start, page_size, __pa(p)); 213 if (rc < 0) { 214 pr_warn("%s: Unable to create vmemmap mapping: %d\n", 215 __func__, rc); 216 return -EFAULT; 217 } 218 } 219 220 return 0; 221 } 222 223 #ifdef CONFIG_MEMORY_HOTPLUG 224 static unsigned long vmemmap_list_free(unsigned long start) 225 { 226 struct vmemmap_backing *vmem_back, *vmem_back_prev; 227 228 vmem_back_prev = vmem_back = vmemmap_list; 229 230 /* look for it with prev pointer recorded */ 231 for (; vmem_back; vmem_back = vmem_back->list) { 232 if (vmem_back->virt_addr == start) 233 break; 234 vmem_back_prev = vmem_back; 235 } 236 237 if (unlikely(!vmem_back)) { 238 WARN_ON(1); 239 return 0; 240 } 241 242 /* remove it from vmemmap_list */ 243 if (vmem_back == vmemmap_list) /* remove head */ 244 vmemmap_list = vmem_back->list; 245 else 246 vmem_back_prev->list = vmem_back->list; 247 248 /* next point to this freed entry */ 249 vmem_back->list = next; 250 next = vmem_back; 251 num_freed++; 252 253 return vmem_back->phys; 254 } 255 256 void __ref vmemmap_free(unsigned long start, unsigned long end, 257 struct vmem_altmap *altmap) 258 { 259 unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; 260 unsigned long page_order = get_order(page_size); 261 unsigned long alt_start = ~0, alt_end = ~0; 262 unsigned long base_pfn; 263 264 start = _ALIGN_DOWN(start, page_size); 265 if (altmap) { 266 alt_start = altmap->base_pfn; 267 alt_end = altmap->base_pfn + altmap->reserve + 268 altmap->free + altmap->alloc + altmap->align; 269 } 270 271 pr_debug("vmemmap_free %lx...%lx\n", start, end); 272 273 for (; start < end; start += page_size) { 274 unsigned long nr_pages, addr; 275 struct page *page; 276 277 /* 278 * the section has already be marked as invalid, so 279 * vmemmap_populated() true means some other sections still 280 * in this page, so skip it. 281 */ 282 if (vmemmap_populated(start, page_size)) 283 continue; 284 285 addr = vmemmap_list_free(start); 286 if (!addr) 287 continue; 288 289 page = pfn_to_page(addr >> PAGE_SHIFT); 290 nr_pages = 1 << page_order; 291 base_pfn = PHYS_PFN(addr); 292 293 if (base_pfn >= alt_start && base_pfn < alt_end) { 294 vmem_altmap_free(altmap, nr_pages); 295 } else if (PageReserved(page)) { 296 /* allocated from bootmem */ 297 if (page_size < PAGE_SIZE) { 298 /* 299 * this shouldn't happen, but if it is 300 * the case, leave the memory there 301 */ 302 WARN_ON_ONCE(1); 303 } else { 304 while (nr_pages--) 305 free_reserved_page(page++); 306 } 307 } else { 308 free_pages((unsigned long)(__va(addr)), page_order); 309 } 310 311 vmemmap_remove_mapping(start, page_size); 312 } 313 } 314 #endif 315 void register_page_bootmem_memmap(unsigned long section_nr, 316 struct page *start_page, unsigned long size) 317 { 318 } 319 320 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 321 322 #ifdef CONFIG_PPC_BOOK3S_64 323 static bool disable_radix = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT); 324 325 static int __init parse_disable_radix(char *p) 326 { 327 bool val; 328 329 if (!p) 330 val = true; 331 else if (kstrtobool(p, &val)) 332 return -EINVAL; 333 334 disable_radix = val; 335 336 return 0; 337 } 338 early_param("disable_radix", parse_disable_radix); 339 340 /* 341 * If we're running under a hypervisor, we need to check the contents of 342 * /chosen/ibm,architecture-vec-5 to see if the hypervisor is willing to do 343 * radix. If not, we clear the radix feature bit so we fall back to hash. 344 */ 345 static void __init early_check_vec5(void) 346 { 347 unsigned long root, chosen; 348 int size; 349 const u8 *vec5; 350 u8 mmu_supported; 351 352 root = of_get_flat_dt_root(); 353 chosen = of_get_flat_dt_subnode_by_name(root, "chosen"); 354 if (chosen == -FDT_ERR_NOTFOUND) { 355 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 356 return; 357 } 358 vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size); 359 if (!vec5) { 360 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 361 return; 362 } 363 if (size <= OV5_INDX(OV5_MMU_SUPPORT)) { 364 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 365 return; 366 } 367 368 /* Check for supported configuration */ 369 mmu_supported = vec5[OV5_INDX(OV5_MMU_SUPPORT)] & 370 OV5_FEAT(OV5_MMU_SUPPORT); 371 if (mmu_supported == OV5_FEAT(OV5_MMU_RADIX)) { 372 /* Hypervisor only supports radix - check enabled && GTSE */ 373 if (!early_radix_enabled()) { 374 pr_warn("WARNING: Ignoring cmdline option disable_radix\n"); 375 } 376 if (!(vec5[OV5_INDX(OV5_RADIX_GTSE)] & 377 OV5_FEAT(OV5_RADIX_GTSE))) { 378 pr_warn("WARNING: Hypervisor doesn't support RADIX with GTSE\n"); 379 } 380 /* Do radix anyway - the hypervisor said we had to */ 381 cur_cpu_spec->mmu_features |= MMU_FTR_TYPE_RADIX; 382 } else if (mmu_supported == OV5_FEAT(OV5_MMU_HASH)) { 383 /* Hypervisor only supports hash - disable radix */ 384 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 385 } 386 } 387 388 void __init mmu_early_init_devtree(void) 389 { 390 /* Disable radix mode based on kernel command line. */ 391 if (disable_radix) 392 cur_cpu_spec->mmu_features &= ~MMU_FTR_TYPE_RADIX; 393 394 /* 395 * Check /chosen/ibm,architecture-vec-5 if running as a guest. 396 * When running bare-metal, we can use radix if we like 397 * even though the ibm,architecture-vec-5 property created by 398 * skiboot doesn't have the necessary bits set. 399 */ 400 if (!(mfmsr() & MSR_HV)) 401 early_check_vec5(); 402 403 if (early_radix_enabled()) 404 radix__early_init_devtree(); 405 else 406 hash__early_init_devtree(); 407 } 408 #endif /* CONFIG_PPC_BOOK3S_64 */ 409