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