arch/powerpc/mm/mem.c

   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/bootmem.h>
  31 #include <linux/highmem.h>
  32 #include <linux/initrd.h>
  33 #include <linux/pagemap.h>
  34 #include <linux/suspend.h>
  35 #include <linux/memblock.h>
  36 #include <linux/hugetlb.h>
  37 #include <linux/slab.h>
  38 #include <linux/vmalloc.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
  66 #ifdef CONFIG_HIGHMEM
  67 pte_t *kmap_pte;
  68 EXPORT_SYMBOL(kmap_pte);
  69 pgprot_t kmap_prot;
  70 EXPORT_SYMBOL(kmap_prot);
  71
  72 static inline pte_t *virt_to_kpte(unsigned long vaddr)
  73 {
  74         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
  75                         vaddr), vaddr), vaddr);
  76 }
  77 #endif
  78
  79 int page_is_ram(unsigned long pfn)
  80 {
  81 #ifndef CONFIG_PPC64    /* XXX for now */
  82         return pfn < max_pfn;
  83 #else
  84         unsigned long paddr = (pfn << PAGE_SHIFT);
  85         struct memblock_region *reg;
  86
  87         for_each_memblock(memory, reg)
  88                 if (paddr >= reg->base && paddr < (reg->base + reg->size))
  89                         return 1;
  90         return 0;
  91 #endif
  92 }
  93
  94 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  95                               unsigned long size, pgprot_t vma_prot)
  96 {
  97         if (ppc_md.phys_mem_access_prot)
  98                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  99
 100         if (!page_is_ram(pfn))
 101                 vma_prot = pgprot_noncached(vma_prot);
 102
 103         return vma_prot;
 104 }
 105 EXPORT_SYMBOL(phys_mem_access_prot);
 106
 107 #ifdef CONFIG_MEMORY_HOTPLUG
 108
 109 #ifdef CONFIG_NUMA
 110 int memory_add_physaddr_to_nid(u64 start)
 111 {
 112         return hot_add_scn_to_nid(start);
 113 }
 114 #endif
 115
 116 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
 117 {
 118         struct pglist_data *pgdata;
 119         struct zone *zone;
 120         unsigned long start_pfn = start >> PAGE_SHIFT;
 121         unsigned long nr_pages = size >> PAGE_SHIFT;
 122         int rc;
 123
 124         pgdata = NODE_DATA(nid);
 125
 126         start = (unsigned long)__va(start);
 127         rc = create_section_mapping(start, start + size);
 128         if (rc) {
 129                 pr_warning(
 130                         "Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
 131                         start, start + size, rc);
 132                 return -EFAULT;
 133         }
 134
 135         /* this should work for most non-highmem platforms */
 136         zone = pgdata->node_zones +
 137                 zone_for_memory(nid, start, size, 0, for_device);
 138
 139         return __add_pages(nid, zone, start_pfn, nr_pages);
 140 }
 141
 142 #ifdef CONFIG_MEMORY_HOTREMOVE
 143 int arch_remove_memory(u64 start, u64 size)
 144 {
 145         unsigned long start_pfn = start >> PAGE_SHIFT;
 146         unsigned long nr_pages = size >> PAGE_SHIFT;
 147         struct zone *zone;
 148         int ret;
 149
 150         zone = page_zone(pfn_to_page(start_pfn));
 151         ret = __remove_pages(zone, start_pfn, nr_pages);
 152         if (ret)
 153                 return ret;
 154
 155         /* Remove htab bolted mappings for this section of memory */
 156         start = (unsigned long)__va(start);
 157         ret = remove_section_mapping(start, start + size);
 158
 159         /* Ensure all vmalloc mappings are flushed in case they also
 160          * hit that section of memory
 161          */
 162         vm_unmap_aliases();
 163
 164         return ret;
 165 }
 166 #endif
 167 #endif /* CONFIG_MEMORY_HOTPLUG */
 168
 169 /*
 170  * walk_memory_resource() needs to make sure there is no holes in a given
 171  * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
 172  * Instead it maintains it in memblock.memory structures.  Walk through the
 173  * memory regions, find holes and callback for contiguous regions.
 174  */
 175 int
 176 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 177                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 178 {
 179         struct memblock_region *reg;
 180         unsigned long end_pfn = start_pfn + nr_pages;
 181         unsigned long tstart, tend;
 182         int ret = -1;
 183
 184         for_each_memblock(memory, reg) {
 185                 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
 186                 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
 187                 if (tstart >= tend)
 188                         continue;
 189                 ret = (*func)(tstart, tend - tstart, arg);
 190                 if (ret)
 191                         break;
 192         }
 193         return ret;
 194 }
 195 EXPORT_SYMBOL_GPL(walk_system_ram_range);
 196
 197 #ifndef CONFIG_NEED_MULTIPLE_NODES
 198 void __init initmem_init(void)
 199 {
 200         max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
 201         min_low_pfn = MEMORY_START >> PAGE_SHIFT;
 202 #ifdef CONFIG_HIGHMEM
 203         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
 204 #endif
 205
 206         /* Place all memblock_regions in the same node and merge contiguous
 207          * memblock_regions
 208          */
 209         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
 210
 211         /* XXX need to clip this if using highmem? */
 212         sparse_memory_present_with_active_regions(0);
 213         sparse_init();
 214 }
 215
 216 /* mark pages that don't exist as nosave */
 217 static int __init mark_nonram_nosave(void)
 218 {
 219         struct memblock_region *reg, *prev = NULL;
 220
 221         for_each_memblock(memory, reg) {
 222                 if (prev &&
 223                     memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
 224                         register_nosave_region(memblock_region_memory_end_pfn(prev),
 225                                                memblock_region_memory_base_pfn(reg));
 226                 prev = reg;
 227         }
 228         return 0;
 229 }
 230 #else /* CONFIG_NEED_MULTIPLE_NODES */
 231 static int __init mark_nonram_nosave(void)
 232 {
 233         return 0;
 234 }
 235 #endif
 236
 237 static bool zone_limits_final;
 238
 239 static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
 240         [0 ... MAX_NR_ZONES - 1] = ~0UL
 241 };
 242
 243 /*
 244  * Restrict the specified zone and all more restrictive zones
 245  * to be below the specified pfn.  May not be called after
 246  * paging_init().
 247  */
 248 void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
 249 {
 250         int i;
 251
 252         if (WARN_ON(zone_limits_final))
 253                 return;
 254
 255         for (i = zone; i >= 0; i--) {
 256                 if (max_zone_pfns[i] > pfn_limit)
 257                         max_zone_pfns[i] = pfn_limit;
 258         }
 259 }
 260
 261 /*
 262  * Find the least restrictive zone that is entirely below the
 263  * specified pfn limit.  Returns < 0 if no suitable zone is found.
 264  *
 265  * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
 266  * systems -- the DMA limit can be higher than any possible real pfn.
 267  */
 268 int dma_pfn_limit_to_zone(u64 pfn_limit)
 269 {
 270         enum zone_type top_zone = ZONE_NORMAL;
 271         int i;
 272
 273 #ifdef CONFIG_HIGHMEM
 274         top_zone = ZONE_HIGHMEM;
 275 #endif
 276
 277         for (i = top_zone; i >= 0; i--) {
 278                 if (max_zone_pfns[i] <= pfn_limit)
 279                         return i;
 280         }
 281
 282         return -EPERM;
 283 }
 284
 285 /*
 286  * paging_init() sets up the page tables - in fact we've already done this.
 287  */
 288 void __init paging_init(void)
 289 {
 290         unsigned long long total_ram = memblock_phys_mem_size();
 291         phys_addr_t top_of_ram = memblock_end_of_DRAM();
 292         enum zone_type top_zone;
 293
 294 #ifdef CONFIG_PPC32
 295         unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
 296         unsigned long end = __fix_to_virt(FIX_HOLE);
 297
 298         for (; v < end; v += PAGE_SIZE)
 299                 map_page(v, 0, 0); /* XXX gross */
 300 #endif
 301
 302 #ifdef CONFIG_HIGHMEM
 303         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 304         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 305
 306         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
 307         kmap_prot = PAGE_KERNEL;
 308 #endif /* CONFIG_HIGHMEM */
 309
 310         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
 311                (unsigned long long)top_of_ram, total_ram);
 312         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 313                (long int)((top_of_ram - total_ram) >> 20));
 314
 315 #ifdef CONFIG_HIGHMEM
 316         top_zone = ZONE_HIGHMEM;
 317         limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
 318 #else
 319         top_zone = ZONE_NORMAL;
 320 #endif
 321
 322         limit_zone_pfn(top_zone, top_of_ram >> PAGE_SHIFT);
 323         zone_limits_final = true;
 324         free_area_init_nodes(max_zone_pfns);
 325
 326         mark_nonram_nosave();
 327 }
 328
 329 void __init mem_init(void)
 330 {
 331         /*
 332          * book3s is limited to 16 page sizes due to encoding this in
 333          * a 4-bit field for slices.
 334          */
 335         BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
 336
 337 #ifdef CONFIG_SWIOTLB
 338         swiotlb_init(0);
 339 #endif
 340
 341         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 342         set_max_mapnr(max_pfn);
 343         free_all_bootmem();
 344
 345 #ifdef CONFIG_HIGHMEM
 346         {
 347                 unsigned long pfn, highmem_mapnr;
 348
 349                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
 350                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 351                         phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
 352                         struct page *page = pfn_to_page(pfn);
 353                         if (!memblock_is_reserved(paddr))
 354                                 free_highmem_page(page);
 355                 }
 356         }
 357 #endif /* CONFIG_HIGHMEM */
 358
 359 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
 360         /*
 361          * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
 362          * functions.... do it here for the non-smp case.
 363          */
 364         per_cpu(next_tlbcam_idx, smp_processor_id()) =
 365                 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 366 #endif
 367
 368         mem_init_print_info(NULL);
 369 #ifdef CONFIG_PPC32
 370         pr_info("Kernel virtual memory layout:\n");
 371         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 372 #ifdef CONFIG_HIGHMEM
 373         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 374                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 375 #endif /* CONFIG_HIGHMEM */
 376 #ifdef CONFIG_NOT_COHERENT_CACHE
 377         pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
 378                 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
 379 #endif /* CONFIG_NOT_COHERENT_CACHE */
 380         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 381                 ioremap_bot, IOREMAP_TOP);
 382         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 383                 VMALLOC_START, VMALLOC_END);
 384 #endif /* CONFIG_PPC32 */
 385 }
 386
 387 void free_initmem(void)
 388 {
 389         ppc_md.progress = ppc_printk_progress;
 390         free_initmem_default(POISON_FREE_INITMEM);
 391 }
 392
 393 #ifdef CONFIG_BLK_DEV_INITRD
 394 void __init free_initrd_mem(unsigned long start, unsigned long end)
 395 {
 396         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 397 }
 398 #endif
 399
 400 /*
 401  * This is called when a page has been modified by the kernel.
 402  * It just marks the page as not i-cache clean.  We do the i-cache
 403  * flush later when the page is given to a user process, if necessary.
 404  */
 405 void flush_dcache_page(struct page *page)
 406 {
 407         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 408                 return;
 409         /* avoid an atomic op if possible */
 410         if (test_bit(PG_arch_1, &page->flags))
 411                 clear_bit(PG_arch_1, &page->flags);
 412 }
 413 EXPORT_SYMBOL(flush_dcache_page);
 414
 415 void flush_dcache_icache_page(struct page *page)
 416 {
 417 #ifdef CONFIG_HUGETLB_PAGE
 418         if (PageCompound(page)) {
 419                 flush_dcache_icache_hugepage(page);
 420                 return;
 421         }
 422 #endif
 423 #if defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 424         /* On 8xx there is no need to kmap since highmem is not supported */
 425         __flush_dcache_icache(page_address(page));
 426 #else
 427         if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
 428                 void *start = kmap_atomic(page);
 429                 __flush_dcache_icache(start);
 430                 kunmap_atomic(start);
 431         } else {
 432                 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 433         }
 434 #endif
 435 }
 436 EXPORT_SYMBOL(flush_dcache_icache_page);
 437
 438 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 439 {
 440         clear_page(page);
 441
 442         /*
 443          * We shouldn't have to do this, but some versions of glibc
 444          * require it (ld.so assumes zero filled pages are icache clean)
 445          * - Anton
 446          */
 447         flush_dcache_page(pg);
 448 }
 449 EXPORT_SYMBOL(clear_user_page);
 450
 451 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 452                     struct page *pg)
 453 {
 454         copy_page(vto, vfrom);
 455
 456         /*
 457          * We should be able to use the following optimisation, however
 458          * there are two problems.
 459          * Firstly a bug in some versions of binutils meant PLT sections
 460          * were not marked executable.
 461          * Secondly the first word in the GOT section is blrl, used
 462          * to establish the GOT address. Until recently the GOT was
 463          * not marked executable.
 464          * - Anton
 465          */
 466 #if 0
 467         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 468                 return;
 469 #endif
 470
 471         flush_dcache_page(pg);
 472 }
 473
 474 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 475                              unsigned long addr, int len)
 476 {
 477         unsigned long maddr;
 478
 479         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 480         flush_icache_range(maddr, maddr + len);
 481         kunmap(page);
 482 }
 483 EXPORT_SYMBOL(flush_icache_user_range);
 484
 485 /*
 486  * This is called at the end of handling a user page fault, when the
 487  * fault has been handled by updating a PTE in the linux page tables.
 488  * We use it to preload an HPTE into the hash table corresponding to
 489  * the updated linux PTE.
 490  *
 491  * This must always be called with the pte lock held.
 492  */
 493 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 494                       pte_t *ptep)
 495 {
 496 #ifdef CONFIG_PPC_STD_MMU
 497         /*
 498          * We don't need to worry about _PAGE_PRESENT here because we are
 499          * called with either mm->page_table_lock held or ptl lock held
 500          */
 501         unsigned long access = 0, trap;
 502
 503         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 504         if (!pte_young(*ptep) || address >= TASK_SIZE)
 505                 return;
 506
 507         /* We try to figure out if we are coming from an instruction
 508          * access fault and pass that down to __hash_page so we avoid
 509          * double-faulting on execution of fresh text. We have to test
 510          * for regs NULL since init will get here first thing at boot
 511          *
 512          * We also avoid filling the hash if not coming from a fault
 513          */
 514         if (current->thread.regs == NULL)
 515                 return;
 516         trap = TRAP(current->thread.regs);
 517         if (trap == 0x400)
 518                 access |= _PAGE_EXEC;
 519         else if (trap != 0x300)
 520                 return;
 521         hash_preload(vma->vm_mm, address, access, trap);
 522 #endif /* CONFIG_PPC_STD_MMU */
 523 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
 524         && defined(CONFIG_HUGETLB_PAGE)
 525         if (is_vm_hugetlb_page(vma))
 526                 book3e_hugetlb_preload(vma, address, *ptep);
 527 #endif
 528 }
 529
 530 /*
 531  * System memory should not be in /proc/iomem but various tools expect it
 532  * (eg kdump).
 533  */
 534 static int __init add_system_ram_resources(void)
 535 {
 536         struct memblock_region *reg;
 537
 538         for_each_memblock(memory, reg) {
 539                 struct resource *res;
 540                 unsigned long base = reg->base;
 541                 unsigned long size = reg->size;
 542
 543                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 544                 WARN_ON(!res);
 545
 546                 if (res) {
 547                         res->name = "System RAM";
 548                         res->start = base;
 549                         res->end = base + size - 1;
 550                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 551                         WARN_ON(request_resource(&iomem_resource, res) < 0);
 552                 }
 553         }
 554
 555         return 0;
 556 }
 557 subsys_initcall(add_system_ram_resources);
 558
 559 #ifdef CONFIG_STRICT_DEVMEM
 560 /*
 561  * devmem_is_allowed(): check to see if /dev/mem access to a certain address
 562  * is valid. The argument is a physical page number.
 563  *
 564  * Access has to be given to non-kernel-ram areas as well, these contain the
 565  * PCI mmio resources as well as potential bios/acpi data regions.
 566  */
 567 int devmem_is_allowed(unsigned long pfn)
 568 {
 569         if (page_is_rtas_user_buf(pfn))
 570                 return 1;
 571         if (iomem_is_exclusive(PFN_PHYS(pfn)))
 572                 return 0;
 573         if (!page_is_ram(pfn))
 574                 return 1;
 575         return 0;
 576 }
 577 #endif /* CONFIG_STRICT_DEVMEM */