1 /* 2 * PowerPC version 3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 4 * 5 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) 6 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 7 * Copyright (C) 1996 Paul Mackerras 8 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com) 9 * 10 * Derived from "arch/i386/mm/init.c" 11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * as published by the Free Software Foundation; either version 16 * 2 of the License, or (at your option) any later version. 17 * 18 */ 19 20 #include <linux/export.h> 21 #include <linux/sched.h> 22 #include <linux/kernel.h> 23 #include <linux/errno.h> 24 #include <linux/string.h> 25 #include <linux/gfp.h> 26 #include <linux/types.h> 27 #include <linux/mm.h> 28 #include <linux/stddef.h> 29 #include <linux/init.h> 30 #include <linux/memblock.h> 31 #include <linux/highmem.h> 32 #include <linux/initrd.h> 33 #include <linux/pagemap.h> 34 #include <linux/suspend.h> 35 #include <linux/hugetlb.h> 36 #include <linux/slab.h> 37 #include <linux/vmalloc.h> 38 #include <linux/memremap.h> 39 40 #include <asm/pgalloc.h> 41 #include <asm/prom.h> 42 #include <asm/io.h> 43 #include <asm/mmu_context.h> 44 #include <asm/pgtable.h> 45 #include <asm/mmu.h> 46 #include <asm/smp.h> 47 #include <asm/machdep.h> 48 #include <asm/btext.h> 49 #include <asm/tlb.h> 50 #include <asm/sections.h> 51 #include <asm/sparsemem.h> 52 #include <asm/vdso.h> 53 #include <asm/fixmap.h> 54 #include <asm/swiotlb.h> 55 #include <asm/rtas.h> 56 57 #include "mmu_decl.h" 58 59 #ifndef CPU_FTR_COHERENT_ICACHE 60 #define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */ 61 #define CPU_FTR_NOEXECUTE 0 62 #endif 63 64 unsigned long long memory_limit; 65 bool init_mem_is_free; 66 67 #ifdef CONFIG_HIGHMEM 68 pte_t *kmap_pte; 69 EXPORT_SYMBOL(kmap_pte); 70 pgprot_t kmap_prot; 71 EXPORT_SYMBOL(kmap_prot); 72 #define TOP_ZONE ZONE_HIGHMEM 73 74 static inline pte_t *virt_to_kpte(unsigned long vaddr) 75 { 76 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), 77 vaddr), vaddr), vaddr); 78 } 79 #else 80 #define TOP_ZONE ZONE_NORMAL 81 #endif 82 83 int page_is_ram(unsigned long pfn) 84 { 85 return memblock_is_memory(__pfn_to_phys(pfn)); 86 } 87 88 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 89 unsigned long size, pgprot_t vma_prot) 90 { 91 if (ppc_md.phys_mem_access_prot) 92 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot); 93 94 if (!page_is_ram(pfn)) 95 vma_prot = pgprot_noncached(vma_prot); 96 97 return vma_prot; 98 } 99 EXPORT_SYMBOL(phys_mem_access_prot); 100 101 #ifdef CONFIG_MEMORY_HOTPLUG 102 103 #ifdef CONFIG_NUMA 104 int memory_add_physaddr_to_nid(u64 start) 105 { 106 return hot_add_scn_to_nid(start); 107 } 108 #endif 109 110 int __weak create_section_mapping(unsigned long start, unsigned long end, int nid) 111 { 112 return -ENODEV; 113 } 114 115 int __weak remove_section_mapping(unsigned long start, unsigned long end) 116 { 117 return -ENODEV; 118 } 119 120 int __meminit arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap, 121 bool want_memblock) 122 { 123 unsigned long start_pfn = start >> PAGE_SHIFT; 124 unsigned long nr_pages = size >> PAGE_SHIFT; 125 int rc; 126 127 resize_hpt_for_hotplug(memblock_phys_mem_size()); 128 129 start = (unsigned long)__va(start); 130 rc = create_section_mapping(start, start + size, nid); 131 if (rc) { 132 pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n", 133 start, start + size, rc); 134 return -EFAULT; 135 } 136 flush_inval_dcache_range(start, start + size); 137 138 return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock); 139 } 140 141 #ifdef CONFIG_MEMORY_HOTREMOVE 142 int __meminit arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) 143 { 144 unsigned long start_pfn = start >> PAGE_SHIFT; 145 unsigned long nr_pages = size >> PAGE_SHIFT; 146 struct page *page; 147 int ret; 148 149 /* 150 * If we have an altmap then we need to skip over any reserved PFNs 151 * when querying the zone. 152 */ 153 page = pfn_to_page(start_pfn); 154 if (altmap) 155 page += vmem_altmap_offset(altmap); 156 157 ret = __remove_pages(page_zone(page), start_pfn, nr_pages, altmap); 158 if (ret) 159 return ret; 160 161 /* Remove htab bolted mappings for this section of memory */ 162 start = (unsigned long)__va(start); 163 flush_inval_dcache_range(start, start + size); 164 ret = remove_section_mapping(start, start + size); 165 166 /* Ensure all vmalloc mappings are flushed in case they also 167 * hit that section of memory 168 */ 169 vm_unmap_aliases(); 170 171 resize_hpt_for_hotplug(memblock_phys_mem_size()); 172 173 return ret; 174 } 175 #endif 176 #endif /* CONFIG_MEMORY_HOTPLUG */ 177 178 /* 179 * walk_memory_resource() needs to make sure there is no holes in a given 180 * memory range. PPC64 does not maintain the memory layout in /proc/iomem. 181 * Instead it maintains it in memblock.memory structures. Walk through the 182 * memory regions, find holes and callback for contiguous regions. 183 */ 184 int 185 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, 186 void *arg, int (*func)(unsigned long, unsigned long, void *)) 187 { 188 struct memblock_region *reg; 189 unsigned long end_pfn = start_pfn + nr_pages; 190 unsigned long tstart, tend; 191 int ret = -1; 192 193 for_each_memblock(memory, reg) { 194 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 195 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 196 if (tstart >= tend) 197 continue; 198 ret = (*func)(tstart, tend - tstart, arg); 199 if (ret) 200 break; 201 } 202 return ret; 203 } 204 EXPORT_SYMBOL_GPL(walk_system_ram_range); 205 206 #ifndef CONFIG_NEED_MULTIPLE_NODES 207 void __init mem_topology_setup(void) 208 { 209 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT; 210 min_low_pfn = MEMORY_START >> PAGE_SHIFT; 211 #ifdef CONFIG_HIGHMEM 212 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT; 213 #endif 214 215 /* Place all memblock_regions in the same node and merge contiguous 216 * memblock_regions 217 */ 218 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0); 219 } 220 221 void __init initmem_init(void) 222 { 223 /* XXX need to clip this if using highmem? */ 224 sparse_memory_present_with_active_regions(0); 225 sparse_init(); 226 } 227 228 /* mark pages that don't exist as nosave */ 229 static int __init mark_nonram_nosave(void) 230 { 231 struct memblock_region *reg, *prev = NULL; 232 233 for_each_memblock(memory, reg) { 234 if (prev && 235 memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg)) 236 register_nosave_region(memblock_region_memory_end_pfn(prev), 237 memblock_region_memory_base_pfn(reg)); 238 prev = reg; 239 } 240 return 0; 241 } 242 #else /* CONFIG_NEED_MULTIPLE_NODES */ 243 static int __init mark_nonram_nosave(void) 244 { 245 return 0; 246 } 247 #endif 248 249 /* 250 * Zones usage: 251 * 252 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be 253 * everything else. GFP_DMA32 page allocations automatically fall back to 254 * ZONE_DMA. 255 * 256 * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to 257 * inform the generic DMA mapping code. 32-bit only devices (if not handled 258 * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get 259 * otherwise served by ZONE_DMA. 260 */ 261 static unsigned long max_zone_pfns[MAX_NR_ZONES]; 262 263 /* 264 * Find the least restrictive zone that is entirely below the 265 * specified pfn limit. Returns < 0 if no suitable zone is found. 266 * 267 * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit 268 * systems -- the DMA limit can be higher than any possible real pfn. 269 */ 270 int dma_pfn_limit_to_zone(u64 pfn_limit) 271 { 272 int i; 273 274 for (i = TOP_ZONE; i >= 0; i--) { 275 if (max_zone_pfns[i] <= pfn_limit) 276 return i; 277 } 278 279 return -EPERM; 280 } 281 282 /* 283 * paging_init() sets up the page tables - in fact we've already done this. 284 */ 285 void __init paging_init(void) 286 { 287 unsigned long long total_ram = memblock_phys_mem_size(); 288 phys_addr_t top_of_ram = memblock_end_of_DRAM(); 289 290 #ifdef CONFIG_PPC32 291 unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1); 292 unsigned long end = __fix_to_virt(FIX_HOLE); 293 294 for (; v < end; v += PAGE_SIZE) 295 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */ 296 #endif 297 298 #ifdef CONFIG_HIGHMEM 299 map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */ 300 pkmap_page_table = virt_to_kpte(PKMAP_BASE); 301 302 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); 303 kmap_prot = PAGE_KERNEL; 304 #endif /* CONFIG_HIGHMEM */ 305 306 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n", 307 (unsigned long long)top_of_ram, total_ram); 308 printk(KERN_DEBUG "Memory hole size: %ldMB\n", 309 (long int)((top_of_ram - total_ram) >> 20)); 310 311 #ifdef CONFIG_ZONE_DMA 312 max_zone_pfns[ZONE_DMA] = min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT); 313 #endif 314 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 315 #ifdef CONFIG_HIGHMEM 316 max_zone_pfns[ZONE_HIGHMEM] = max_pfn; 317 #endif 318 319 free_area_init_nodes(max_zone_pfns); 320 321 mark_nonram_nosave(); 322 } 323 324 void __init mem_init(void) 325 { 326 /* 327 * book3s is limited to 16 page sizes due to encoding this in 328 * a 4-bit field for slices. 329 */ 330 BUILD_BUG_ON(MMU_PAGE_COUNT > 16); 331 332 #ifdef CONFIG_SWIOTLB 333 swiotlb_init(0); 334 #endif 335 336 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); 337 set_max_mapnr(max_pfn); 338 memblock_free_all(); 339 340 #ifdef CONFIG_HIGHMEM 341 { 342 unsigned long pfn, highmem_mapnr; 343 344 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT; 345 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) { 346 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT; 347 struct page *page = pfn_to_page(pfn); 348 if (!memblock_is_reserved(paddr)) 349 free_highmem_page(page); 350 } 351 } 352 #endif /* CONFIG_HIGHMEM */ 353 354 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP) 355 /* 356 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up 357 * functions.... do it here for the non-smp case. 358 */ 359 per_cpu(next_tlbcam_idx, smp_processor_id()) = 360 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1; 361 #endif 362 363 mem_init_print_info(NULL); 364 #ifdef CONFIG_PPC32 365 pr_info("Kernel virtual memory layout:\n"); 366 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP); 367 #ifdef CONFIG_HIGHMEM 368 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n", 369 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP)); 370 #endif /* CONFIG_HIGHMEM */ 371 #ifdef CONFIG_NOT_COHERENT_CACHE 372 pr_info(" * 0x%08lx..0x%08lx : consistent mem\n", 373 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE); 374 #endif /* CONFIG_NOT_COHERENT_CACHE */ 375 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n", 376 ioremap_bot, IOREMAP_TOP); 377 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n", 378 VMALLOC_START, VMALLOC_END); 379 #endif /* CONFIG_PPC32 */ 380 } 381 382 void free_initmem(void) 383 { 384 ppc_md.progress = ppc_printk_progress; 385 mark_initmem_nx(); 386 init_mem_is_free = true; 387 free_initmem_default(POISON_FREE_INITMEM); 388 } 389 390 #ifdef CONFIG_BLK_DEV_INITRD 391 void __init free_initrd_mem(unsigned long start, unsigned long end) 392 { 393 free_reserved_area((void *)start, (void *)end, -1, "initrd"); 394 } 395 #endif 396 397 /* 398 * This is called when a page has been modified by the kernel. 399 * It just marks the page as not i-cache clean. We do the i-cache 400 * flush later when the page is given to a user process, if necessary. 401 */ 402 void flush_dcache_page(struct page *page) 403 { 404 if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) 405 return; 406 /* avoid an atomic op if possible */ 407 if (test_bit(PG_arch_1, &page->flags)) 408 clear_bit(PG_arch_1, &page->flags); 409 } 410 EXPORT_SYMBOL(flush_dcache_page); 411 412 void flush_dcache_icache_page(struct page *page) 413 { 414 #ifdef CONFIG_HUGETLB_PAGE 415 if (PageCompound(page)) { 416 flush_dcache_icache_hugepage(page); 417 return; 418 } 419 #endif 420 #if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64) 421 /* On 8xx there is no need to kmap since highmem is not supported */ 422 __flush_dcache_icache(page_address(page)); 423 #else 424 if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) { 425 void *start = kmap_atomic(page); 426 __flush_dcache_icache(start); 427 kunmap_atomic(start); 428 } else { 429 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT); 430 } 431 #endif 432 } 433 EXPORT_SYMBOL(flush_dcache_icache_page); 434 435 void clear_user_page(void *page, unsigned long vaddr, struct page *pg) 436 { 437 clear_page(page); 438 439 /* 440 * We shouldn't have to do this, but some versions of glibc 441 * require it (ld.so assumes zero filled pages are icache clean) 442 * - Anton 443 */ 444 flush_dcache_page(pg); 445 } 446 EXPORT_SYMBOL(clear_user_page); 447 448 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr, 449 struct page *pg) 450 { 451 copy_page(vto, vfrom); 452 453 /* 454 * We should be able to use the following optimisation, however 455 * there are two problems. 456 * Firstly a bug in some versions of binutils meant PLT sections 457 * were not marked executable. 458 * Secondly the first word in the GOT section is blrl, used 459 * to establish the GOT address. Until recently the GOT was 460 * not marked executable. 461 * - Anton 462 */ 463 #if 0 464 if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0)) 465 return; 466 #endif 467 468 flush_dcache_page(pg); 469 } 470 471 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page, 472 unsigned long addr, int len) 473 { 474 unsigned long maddr; 475 476 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK); 477 flush_icache_range(maddr, maddr + len); 478 kunmap(page); 479 } 480 EXPORT_SYMBOL(flush_icache_user_range); 481 482 /* 483 * This is called at the end of handling a user page fault, when the 484 * fault has been handled by updating a PTE in the linux page tables. 485 * We use it to preload an HPTE into the hash table corresponding to 486 * the updated linux PTE. 487 * 488 * This must always be called with the pte lock held. 489 */ 490 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, 491 pte_t *ptep) 492 { 493 #ifdef CONFIG_PPC_BOOK3S 494 /* 495 * We don't need to worry about _PAGE_PRESENT here because we are 496 * called with either mm->page_table_lock held or ptl lock held 497 */ 498 unsigned long trap; 499 bool is_exec; 500 501 if (radix_enabled()) { 502 prefetch((void *)address); 503 return; 504 } 505 506 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */ 507 if (!pte_young(*ptep) || address >= TASK_SIZE) 508 return; 509 510 /* We try to figure out if we are coming from an instruction 511 * access fault and pass that down to __hash_page so we avoid 512 * double-faulting on execution of fresh text. We have to test 513 * for regs NULL since init will get here first thing at boot 514 * 515 * We also avoid filling the hash if not coming from a fault 516 */ 517 518 trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL; 519 switch (trap) { 520 case 0x300: 521 is_exec = false; 522 break; 523 case 0x400: 524 is_exec = true; 525 break; 526 default: 527 return; 528 } 529 530 hash_preload(vma->vm_mm, address, is_exec, trap); 531 #endif /* CONFIG_PPC_BOOK3S */ 532 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \ 533 && defined(CONFIG_HUGETLB_PAGE) 534 if (is_vm_hugetlb_page(vma)) 535 book3e_hugetlb_preload(vma, address, *ptep); 536 #endif 537 } 538 539 /* 540 * System memory should not be in /proc/iomem but various tools expect it 541 * (eg kdump). 542 */ 543 static int __init add_system_ram_resources(void) 544 { 545 struct memblock_region *reg; 546 547 for_each_memblock(memory, reg) { 548 struct resource *res; 549 unsigned long base = reg->base; 550 unsigned long size = reg->size; 551 552 res = kzalloc(sizeof(struct resource), GFP_KERNEL); 553 WARN_ON(!res); 554 555 if (res) { 556 res->name = "System RAM"; 557 res->start = base; 558 res->end = base + size - 1; 559 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 560 WARN_ON(request_resource(&iomem_resource, res) < 0); 561 } 562 } 563 564 return 0; 565 } 566 subsys_initcall(add_system_ram_resources); 567 568 #ifdef CONFIG_STRICT_DEVMEM 569 /* 570 * devmem_is_allowed(): check to see if /dev/mem access to a certain address 571 * is valid. The argument is a physical page number. 572 * 573 * Access has to be given to non-kernel-ram areas as well, these contain the 574 * PCI mmio resources as well as potential bios/acpi data regions. 575 */ 576 int devmem_is_allowed(unsigned long pfn) 577 { 578 if (page_is_rtas_user_buf(pfn)) 579 return 1; 580 if (iomem_is_exclusive(PFN_PHYS(pfn))) 581 return 0; 582 if (!page_is_ram(pfn)) 583 return 1; 584 return 0; 585 } 586 #endif /* CONFIG_STRICT_DEVMEM */ 587