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 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com) 10 * 11 * Derived from "arch/i386/mm/init.c" 12 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 13 */ 14 15 #include <linux/export.h> 16 #include <linux/sched.h> 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/string.h> 20 #include <linux/gfp.h> 21 #include <linux/types.h> 22 #include <linux/mm.h> 23 #include <linux/stddef.h> 24 #include <linux/init.h> 25 #include <linux/memblock.h> 26 #include <linux/highmem.h> 27 #include <linux/initrd.h> 28 #include <linux/pagemap.h> 29 #include <linux/suspend.h> 30 #include <linux/hugetlb.h> 31 #include <linux/slab.h> 32 #include <linux/vmalloc.h> 33 #include <linux/memremap.h> 34 35 #include <asm/pgalloc.h> 36 #include <asm/prom.h> 37 #include <asm/io.h> 38 #include <asm/mmu_context.h> 39 #include <asm/pgtable.h> 40 #include <asm/mmu.h> 41 #include <asm/smp.h> 42 #include <asm/machdep.h> 43 #include <asm/btext.h> 44 #include <asm/tlb.h> 45 #include <asm/sections.h> 46 #include <asm/sparsemem.h> 47 #include <asm/vdso.h> 48 #include <asm/fixmap.h> 49 #include <asm/swiotlb.h> 50 #include <asm/rtas.h> 51 52 #include <mm/mmu_decl.h> 53 54 #ifndef CPU_FTR_COHERENT_ICACHE 55 #define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */ 56 #define CPU_FTR_NOEXECUTE 0 57 #endif 58 59 unsigned long long memory_limit; 60 bool init_mem_is_free; 61 62 #ifdef CONFIG_HIGHMEM 63 pte_t *kmap_pte; 64 EXPORT_SYMBOL(kmap_pte); 65 pgprot_t kmap_prot; 66 EXPORT_SYMBOL(kmap_prot); 67 68 static inline pte_t *virt_to_kpte(unsigned long vaddr) 69 { 70 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 71 vaddr), vaddr), vaddr); 72 } 73 #endif 74 75 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 76 unsigned long size, pgprot_t vma_prot) 77 { 78 if (ppc_md.phys_mem_access_prot) 79 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot); 80 81 if (!page_is_ram(pfn)) 82 vma_prot = pgprot_noncached(vma_prot); 83 84 return vma_prot; 85 } 86 EXPORT_SYMBOL(phys_mem_access_prot); 87 88 #ifdef CONFIG_MEMORY_HOTPLUG 89 90 #ifdef CONFIG_NUMA 91 int memory_add_physaddr_to_nid(u64 start) 92 { 93 return hot_add_scn_to_nid(start); 94 } 95 #endif 96 97 int __weak create_section_mapping(unsigned long start, unsigned long end, int nid) 98 { 99 return -ENODEV; 100 } 101 102 int __weak remove_section_mapping(unsigned long start, unsigned long end) 103 { 104 return -ENODEV; 105 } 106 107 int __ref arch_add_memory(int nid, u64 start, u64 size, 108 struct mhp_restrictions *restrictions) 109 { 110 unsigned long start_pfn = start >> PAGE_SHIFT; 111 unsigned long nr_pages = size >> PAGE_SHIFT; 112 int rc; 113 114 resize_hpt_for_hotplug(memblock_phys_mem_size()); 115 116 start = (unsigned long)__va(start); 117 rc = create_section_mapping(start, start + size, nid); 118 if (rc) { 119 pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n", 120 start, start + size, rc); 121 return -EFAULT; 122 } 123 flush_inval_dcache_range(start, start + size); 124 125 return __add_pages(nid, start_pfn, nr_pages, restrictions); 126 } 127 128 #ifdef CONFIG_MEMORY_HOTREMOVE 129 void __ref arch_remove_memory(int nid, u64 start, u64 size, 130 struct vmem_altmap *altmap) 131 { 132 unsigned long start_pfn = start >> PAGE_SHIFT; 133 unsigned long nr_pages = size >> PAGE_SHIFT; 134 struct page *page; 135 int ret; 136 137 /* 138 * If we have an altmap then we need to skip over any reserved PFNs 139 * when querying the zone. 140 */ 141 page = pfn_to_page(start_pfn); 142 if (altmap) 143 page += vmem_altmap_offset(altmap); 144 145 __remove_pages(page_zone(page), start_pfn, nr_pages, altmap); 146 147 /* Remove htab bolted mappings for this section of memory */ 148 start = (unsigned long)__va(start); 149 flush_inval_dcache_range(start, start + size); 150 ret = remove_section_mapping(start, start + size); 151 WARN_ON_ONCE(ret); 152 153 /* Ensure all vmalloc mappings are flushed in case they also 154 * hit that section of memory 155 */ 156 vm_unmap_aliases(); 157 158 if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC) 159 pr_warn("Hash collision while resizing HPT\n"); 160 } 161 #endif 162 #endif /* CONFIG_MEMORY_HOTPLUG */ 163 164 #ifndef CONFIG_NEED_MULTIPLE_NODES 165 void __init mem_topology_setup(void) 166 { 167 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT; 168 min_low_pfn = MEMORY_START >> PAGE_SHIFT; 169 #ifdef CONFIG_HIGHMEM 170 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT; 171 #endif 172 173 /* Place all memblock_regions in the same node and merge contiguous 174 * memblock_regions 175 */ 176 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0); 177 } 178 179 void __init initmem_init(void) 180 { 181 /* XXX need to clip this if using highmem? */ 182 sparse_memory_present_with_active_regions(0); 183 sparse_init(); 184 } 185 186 /* mark pages that don't exist as nosave */ 187 static int __init mark_nonram_nosave(void) 188 { 189 struct memblock_region *reg, *prev = NULL; 190 191 for_each_memblock(memory, reg) { 192 if (prev && 193 memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg)) 194 register_nosave_region(memblock_region_memory_end_pfn(prev), 195 memblock_region_memory_base_pfn(reg)); 196 prev = reg; 197 } 198 return 0; 199 } 200 #else /* CONFIG_NEED_MULTIPLE_NODES */ 201 static int __init mark_nonram_nosave(void) 202 { 203 return 0; 204 } 205 #endif 206 207 /* 208 * Zones usage: 209 * 210 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be 211 * everything else. GFP_DMA32 page allocations automatically fall back to 212 * ZONE_DMA. 213 * 214 * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to 215 * inform the generic DMA mapping code. 32-bit only devices (if not handled 216 * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get 217 * otherwise served by ZONE_DMA. 218 */ 219 static unsigned long max_zone_pfns[MAX_NR_ZONES]; 220 221 /* 222 * paging_init() sets up the page tables - in fact we've already done this. 223 */ 224 void __init paging_init(void) 225 { 226 unsigned long long total_ram = memblock_phys_mem_size(); 227 phys_addr_t top_of_ram = memblock_end_of_DRAM(); 228 229 #ifdef CONFIG_PPC32 230 unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1); 231 unsigned long end = __fix_to_virt(FIX_HOLE); 232 233 for (; v < end; v += PAGE_SIZE) 234 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */ 235 #endif 236 237 #ifdef CONFIG_HIGHMEM 238 map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */ 239 pkmap_page_table = virt_to_kpte(PKMAP_BASE); 240 241 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); 242 kmap_prot = PAGE_KERNEL; 243 #endif /* CONFIG_HIGHMEM */ 244 245 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n", 246 (unsigned long long)top_of_ram, total_ram); 247 printk(KERN_DEBUG "Memory hole size: %ldMB\n", 248 (long int)((top_of_ram - total_ram) >> 20)); 249 250 #ifdef CONFIG_ZONE_DMA 251 max_zone_pfns[ZONE_DMA] = min(max_low_pfn, 252 ((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT); 253 #endif 254 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 255 #ifdef CONFIG_HIGHMEM 256 max_zone_pfns[ZONE_HIGHMEM] = max_pfn; 257 #endif 258 259 free_area_init_nodes(max_zone_pfns); 260 261 mark_nonram_nosave(); 262 } 263 264 void __init mem_init(void) 265 { 266 /* 267 * book3s is limited to 16 page sizes due to encoding this in 268 * a 4-bit field for slices. 269 */ 270 BUILD_BUG_ON(MMU_PAGE_COUNT > 16); 271 272 #ifdef CONFIG_SWIOTLB 273 swiotlb_init(0); 274 #endif 275 276 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 277 set_max_mapnr(max_pfn); 278 memblock_free_all(); 279 280 #ifdef CONFIG_HIGHMEM 281 { 282 unsigned long pfn, highmem_mapnr; 283 284 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT; 285 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) { 286 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT; 287 struct page *page = pfn_to_page(pfn); 288 if (!memblock_is_reserved(paddr)) 289 free_highmem_page(page); 290 } 291 } 292 #endif /* CONFIG_HIGHMEM */ 293 294 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP) 295 /* 296 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up 297 * functions.... do it here for the non-smp case. 298 */ 299 per_cpu(next_tlbcam_idx, smp_processor_id()) = 300 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1; 301 #endif 302 303 mem_init_print_info(NULL); 304 #ifdef CONFIG_PPC32 305 pr_info("Kernel virtual memory layout:\n"); 306 #ifdef CONFIG_KASAN 307 pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n", 308 KASAN_SHADOW_START, KASAN_SHADOW_END); 309 #endif 310 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP); 311 #ifdef CONFIG_HIGHMEM 312 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n", 313 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP)); 314 #endif /* CONFIG_HIGHMEM */ 315 #ifdef CONFIG_NOT_COHERENT_CACHE 316 pr_info(" * 0x%08lx..0x%08lx : consistent mem\n", 317 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE); 318 #endif /* CONFIG_NOT_COHERENT_CACHE */ 319 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n", 320 ioremap_bot, IOREMAP_TOP); 321 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n", 322 VMALLOC_START, VMALLOC_END); 323 #endif /* CONFIG_PPC32 */ 324 } 325 326 void free_initmem(void) 327 { 328 ppc_md.progress = ppc_printk_progress; 329 mark_initmem_nx(); 330 init_mem_is_free = true; 331 free_initmem_default(POISON_FREE_INITMEM); 332 } 333 334 /* 335 * This is called when a page has been modified by the kernel. 336 * It just marks the page as not i-cache clean. We do the i-cache 337 * flush later when the page is given to a user process, if necessary. 338 */ 339 void flush_dcache_page(struct page *page) 340 { 341 if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) 342 return; 343 /* avoid an atomic op if possible */ 344 if (test_bit(PG_arch_1, &page->flags)) 345 clear_bit(PG_arch_1, &page->flags); 346 } 347 EXPORT_SYMBOL(flush_dcache_page); 348 349 void flush_dcache_icache_page(struct page *page) 350 { 351 #ifdef CONFIG_HUGETLB_PAGE 352 if (PageCompound(page)) { 353 flush_dcache_icache_hugepage(page); 354 return; 355 } 356 #endif 357 #if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64) 358 /* On 8xx there is no need to kmap since highmem is not supported */ 359 __flush_dcache_icache(page_address(page)); 360 #else 361 if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) { 362 void *start = kmap_atomic(page); 363 __flush_dcache_icache(start); 364 kunmap_atomic(start); 365 } else { 366 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT); 367 } 368 #endif 369 } 370 EXPORT_SYMBOL(flush_dcache_icache_page); 371 372 void clear_user_page(void *page, unsigned long vaddr, struct page *pg) 373 { 374 clear_page(page); 375 376 /* 377 * We shouldn't have to do this, but some versions of glibc 378 * require it (ld.so assumes zero filled pages are icache clean) 379 * - Anton 380 */ 381 flush_dcache_page(pg); 382 } 383 EXPORT_SYMBOL(clear_user_page); 384 385 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, 386 struct page *pg) 387 { 388 copy_page(vto, vfrom); 389 390 /* 391 * We should be able to use the following optimisation, however 392 * there are two problems. 393 * Firstly a bug in some versions of binutils meant PLT sections 394 * were not marked executable. 395 * Secondly the first word in the GOT section is blrl, used 396 * to establish the GOT address. Until recently the GOT was 397 * not marked executable. 398 * - Anton 399 */ 400 #if 0 401 if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0)) 402 return; 403 #endif 404 405 flush_dcache_page(pg); 406 } 407 408 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page, 409 unsigned long addr, int len) 410 { 411 unsigned long maddr; 412 413 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK); 414 flush_icache_range(maddr, maddr + len); 415 kunmap(page); 416 } 417 EXPORT_SYMBOL(flush_icache_user_range); 418 419 /* 420 * This is called at the end of handling a user page fault, when the 421 * fault has been handled by updating a PTE in the linux page tables. 422 * We use it to preload an HPTE into the hash table corresponding to 423 * the updated linux PTE. 424 * 425 * This must always be called with the pte lock held. 426 */ 427 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, 428 pte_t *ptep) 429 { 430 #ifdef CONFIG_PPC_BOOK3S 431 /* 432 * We don't need to worry about _PAGE_PRESENT here because we are 433 * called with either mm->page_table_lock held or ptl lock held 434 */ 435 unsigned long trap; 436 bool is_exec; 437 438 if (radix_enabled()) { 439 prefetch((void *)address); 440 return; 441 } 442 443 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */ 444 if (!pte_young(*ptep) || address >= TASK_SIZE) 445 return; 446 447 /* We try to figure out if we are coming from an instruction 448 * access fault and pass that down to __hash_page so we avoid 449 * double-faulting on execution of fresh text. We have to test 450 * for regs NULL since init will get here first thing at boot 451 * 452 * We also avoid filling the hash if not coming from a fault 453 */ 454 455 trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL; 456 switch (trap) { 457 case 0x300: 458 is_exec = false; 459 break; 460 case 0x400: 461 is_exec = true; 462 break; 463 default: 464 return; 465 } 466 467 hash_preload(vma->vm_mm, address, is_exec, trap); 468 #endif /* CONFIG_PPC_BOOK3S */ 469 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \ 470 && defined(CONFIG_HUGETLB_PAGE) 471 if (is_vm_hugetlb_page(vma)) 472 book3e_hugetlb_preload(vma, address, *ptep); 473 #endif 474 } 475 476 /* 477 * System memory should not be in /proc/iomem but various tools expect it 478 * (eg kdump). 479 */ 480 static int __init add_system_ram_resources(void) 481 { 482 struct memblock_region *reg; 483 484 for_each_memblock(memory, reg) { 485 struct resource *res; 486 unsigned long base = reg->base; 487 unsigned long size = reg->size; 488 489 res = kzalloc(sizeof(struct resource), GFP_KERNEL); 490 WARN_ON(!res); 491 492 if (res) { 493 res->name = "System RAM"; 494 res->start = base; 495 res->end = base + size - 1; 496 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 497 WARN_ON(request_resource(&iomem_resource, res) < 0); 498 } 499 } 500 501 return 0; 502 } 503 subsys_initcall(add_system_ram_resources); 504 505 #ifdef CONFIG_STRICT_DEVMEM 506 /* 507 * devmem_is_allowed(): check to see if /dev/mem access to a certain address 508 * is valid. The argument is a physical page number. 509 * 510 * Access has to be given to non-kernel-ram areas as well, these contain the 511 * PCI mmio resources as well as potential bios/acpi data regions. 512 */ 513 int devmem_is_allowed(unsigned long pfn) 514 { 515 if (page_is_rtas_user_buf(pfn)) 516 return 1; 517 if (iomem_is_exclusive(PFN_PHYS(pfn))) 518 return 0; 519 if (!page_is_ram(pfn)) 520 return 1; 521 return 0; 522 } 523 #endif /* CONFIG_STRICT_DEVMEM */ 524 525 /* 526 * This is defined in kernel/resource.c but only powerpc needs to export it, for 527 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed. 528 */ 529 EXPORT_SYMBOL_GPL(walk_system_ram_range); 530