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, 0x7fffffffUL >> PAGE_SHIFT); 252 #endif 253 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 254 #ifdef CONFIG_HIGHMEM 255 max_zone_pfns[ZONE_HIGHMEM] = max_pfn; 256 #endif 257 258 free_area_init_nodes(max_zone_pfns); 259 260 mark_nonram_nosave(); 261 } 262 263 void __init mem_init(void) 264 { 265 /* 266 * book3s is limited to 16 page sizes due to encoding this in 267 * a 4-bit field for slices. 268 */ 269 BUILD_BUG_ON(MMU_PAGE_COUNT > 16); 270 271 #ifdef CONFIG_SWIOTLB 272 swiotlb_init(0); 273 #endif 274 275 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 276 set_max_mapnr(max_pfn); 277 memblock_free_all(); 278 279 #ifdef CONFIG_HIGHMEM 280 { 281 unsigned long pfn, highmem_mapnr; 282 283 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT; 284 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) { 285 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT; 286 struct page *page = pfn_to_page(pfn); 287 if (!memblock_is_reserved(paddr)) 288 free_highmem_page(page); 289 } 290 } 291 #endif /* CONFIG_HIGHMEM */ 292 293 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP) 294 /* 295 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up 296 * functions.... do it here for the non-smp case. 297 */ 298 per_cpu(next_tlbcam_idx, smp_processor_id()) = 299 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1; 300 #endif 301 302 mem_init_print_info(NULL); 303 #ifdef CONFIG_PPC32 304 pr_info("Kernel virtual memory layout:\n"); 305 #ifdef CONFIG_KASAN 306 pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n", 307 KASAN_SHADOW_START, KASAN_SHADOW_END); 308 #endif 309 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP); 310 #ifdef CONFIG_HIGHMEM 311 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n", 312 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP)); 313 #endif /* CONFIG_HIGHMEM */ 314 #ifdef CONFIG_NOT_COHERENT_CACHE 315 pr_info(" * 0x%08lx..0x%08lx : consistent mem\n", 316 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE); 317 #endif /* CONFIG_NOT_COHERENT_CACHE */ 318 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n", 319 ioremap_bot, IOREMAP_TOP); 320 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n", 321 VMALLOC_START, VMALLOC_END); 322 #endif /* CONFIG_PPC32 */ 323 } 324 325 void free_initmem(void) 326 { 327 ppc_md.progress = ppc_printk_progress; 328 mark_initmem_nx(); 329 init_mem_is_free = true; 330 free_initmem_default(POISON_FREE_INITMEM); 331 } 332 333 /* 334 * This is called when a page has been modified by the kernel. 335 * It just marks the page as not i-cache clean. We do the i-cache 336 * flush later when the page is given to a user process, if necessary. 337 */ 338 void flush_dcache_page(struct page *page) 339 { 340 if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) 341 return; 342 /* avoid an atomic op if possible */ 343 if (test_bit(PG_arch_1, &page->flags)) 344 clear_bit(PG_arch_1, &page->flags); 345 } 346 EXPORT_SYMBOL(flush_dcache_page); 347 348 void flush_dcache_icache_page(struct page *page) 349 { 350 #ifdef CONFIG_HUGETLB_PAGE 351 if (PageCompound(page)) { 352 flush_dcache_icache_hugepage(page); 353 return; 354 } 355 #endif 356 #if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64) 357 /* On 8xx there is no need to kmap since highmem is not supported */ 358 __flush_dcache_icache(page_address(page)); 359 #else 360 if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) { 361 void *start = kmap_atomic(page); 362 __flush_dcache_icache(start); 363 kunmap_atomic(start); 364 } else { 365 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT); 366 } 367 #endif 368 } 369 EXPORT_SYMBOL(flush_dcache_icache_page); 370 371 void clear_user_page(void *page, unsigned long vaddr, struct page *pg) 372 { 373 clear_page(page); 374 375 /* 376 * We shouldn't have to do this, but some versions of glibc 377 * require it (ld.so assumes zero filled pages are icache clean) 378 * - Anton 379 */ 380 flush_dcache_page(pg); 381 } 382 EXPORT_SYMBOL(clear_user_page); 383 384 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, 385 struct page *pg) 386 { 387 copy_page(vto, vfrom); 388 389 /* 390 * We should be able to use the following optimisation, however 391 * there are two problems. 392 * Firstly a bug in some versions of binutils meant PLT sections 393 * were not marked executable. 394 * Secondly the first word in the GOT section is blrl, used 395 * to establish the GOT address. Until recently the GOT was 396 * not marked executable. 397 * - Anton 398 */ 399 #if 0 400 if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0)) 401 return; 402 #endif 403 404 flush_dcache_page(pg); 405 } 406 407 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page, 408 unsigned long addr, int len) 409 { 410 unsigned long maddr; 411 412 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK); 413 flush_icache_range(maddr, maddr + len); 414 kunmap(page); 415 } 416 EXPORT_SYMBOL(flush_icache_user_range); 417 418 /* 419 * This is called at the end of handling a user page fault, when the 420 * fault has been handled by updating a PTE in the linux page tables. 421 * We use it to preload an HPTE into the hash table corresponding to 422 * the updated linux PTE. 423 * 424 * This must always be called with the pte lock held. 425 */ 426 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, 427 pte_t *ptep) 428 { 429 #ifdef CONFIG_PPC_BOOK3S 430 /* 431 * We don't need to worry about _PAGE_PRESENT here because we are 432 * called with either mm->page_table_lock held or ptl lock held 433 */ 434 unsigned long trap; 435 bool is_exec; 436 437 if (radix_enabled()) { 438 prefetch((void *)address); 439 return; 440 } 441 442 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */ 443 if (!pte_young(*ptep) || address >= TASK_SIZE) 444 return; 445 446 /* We try to figure out if we are coming from an instruction 447 * access fault and pass that down to __hash_page so we avoid 448 * double-faulting on execution of fresh text. We have to test 449 * for regs NULL since init will get here first thing at boot 450 * 451 * We also avoid filling the hash if not coming from a fault 452 */ 453 454 trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL; 455 switch (trap) { 456 case 0x300: 457 is_exec = false; 458 break; 459 case 0x400: 460 is_exec = true; 461 break; 462 default: 463 return; 464 } 465 466 hash_preload(vma->vm_mm, address, is_exec, trap); 467 #endif /* CONFIG_PPC_BOOK3S */ 468 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \ 469 && defined(CONFIG_HUGETLB_PAGE) 470 if (is_vm_hugetlb_page(vma)) 471 book3e_hugetlb_preload(vma, address, *ptep); 472 #endif 473 } 474 475 /* 476 * System memory should not be in /proc/iomem but various tools expect it 477 * (eg kdump). 478 */ 479 static int __init add_system_ram_resources(void) 480 { 481 struct memblock_region *reg; 482 483 for_each_memblock(memory, reg) { 484 struct resource *res; 485 unsigned long base = reg->base; 486 unsigned long size = reg->size; 487 488 res = kzalloc(sizeof(struct resource), GFP_KERNEL); 489 WARN_ON(!res); 490 491 if (res) { 492 res->name = "System RAM"; 493 res->start = base; 494 res->end = base + size - 1; 495 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 496 WARN_ON(request_resource(&iomem_resource, res) < 0); 497 } 498 } 499 500 return 0; 501 } 502 subsys_initcall(add_system_ram_resources); 503 504 #ifdef CONFIG_STRICT_DEVMEM 505 /* 506 * devmem_is_allowed(): check to see if /dev/mem access to a certain address 507 * is valid. The argument is a physical page number. 508 * 509 * Access has to be given to non-kernel-ram areas as well, these contain the 510 * PCI mmio resources as well as potential bios/acpi data regions. 511 */ 512 int devmem_is_allowed(unsigned long pfn) 513 { 514 if (page_is_rtas_user_buf(pfn)) 515 return 1; 516 if (iomem_is_exclusive(PFN_PHYS(pfn))) 517 return 0; 518 if (!page_is_ram(pfn)) 519 return 1; 520 return 0; 521 } 522 #endif /* CONFIG_STRICT_DEVMEM */ 523 524 /* 525 * This is defined in kernel/resource.c but only powerpc needs to export it, for 526 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed. 527 */ 528 EXPORT_SYMBOL_GPL(walk_system_ram_range); 529