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 #define TOP_ZONE ZONE_HIGHMEM
  72
  73 static inline pte_t *virt_to_kpte(unsigned long vaddr)
  74 {
  75         return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
  76                         vaddr), vaddr), vaddr);
  77 }
  78 #else
  79 #define TOP_ZONE ZONE_NORMAL
  80 #endif
  81
  82 int page_is_ram(unsigned long pfn)
  83 {
  84 #ifndef CONFIG_PPC64    /* XXX for now */
  85         return pfn < max_pfn;
  86 #else
  87         unsigned long paddr = (pfn << PAGE_SHIFT);
  88         struct memblock_region *reg;
  89
  90         for_each_memblock(memory, reg)
  91                 if (paddr >= reg->base && paddr < (reg->base + reg->size))
  92                         return 1;
  93         return 0;
  94 #endif
  95 }
  96
  97 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  98                               unsigned long size, pgprot_t vma_prot)
  99 {
 100         if (ppc_md.phys_mem_access_prot)
 101                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
 102
 103         if (!page_is_ram(pfn))
 104                 vma_prot = pgprot_noncached(vma_prot);
 105
 106         return vma_prot;
 107 }
 108 EXPORT_SYMBOL(phys_mem_access_prot);
 109
 110 #ifdef CONFIG_MEMORY_HOTPLUG
 111
 112 #ifdef CONFIG_NUMA
 113 int memory_add_physaddr_to_nid(u64 start)
 114 {
 115         return hot_add_scn_to_nid(start);
 116 }
 117 #endif
 118
 119 int __weak create_section_mapping(unsigned long start, unsigned long end)
 120 {
 121         return -ENODEV;
 122 }
 123
 124 int __weak remove_section_mapping(unsigned long start, unsigned long end)
 125 {
 126         return -ENODEV;
 127 }
 128
 129 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
 130 {
 131         struct pglist_data *pgdata;
 132         struct zone *zone;
 133         unsigned long start_pfn = start >> PAGE_SHIFT;
 134         unsigned long nr_pages = size >> PAGE_SHIFT;
 135         int rc;
 136
 137         pgdata = NODE_DATA(nid);
 138
 139         start = (unsigned long)__va(start);
 140         rc = create_section_mapping(start, start + size);
 141         if (rc) {
 142                 pr_warning(
 143                         "Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
 144                         start, start + size, rc);
 145                 return -EFAULT;
 146         }
 147
 148         /* this should work for most non-highmem platforms */
 149         zone = pgdata->node_zones +
 150                 zone_for_memory(nid, start, size, 0, for_device);
 151
 152         return __add_pages(nid, zone, start_pfn, nr_pages);
 153 }
 154
 155 #ifdef CONFIG_MEMORY_HOTREMOVE
 156 int arch_remove_memory(u64 start, u64 size)
 157 {
 158         unsigned long start_pfn = start >> PAGE_SHIFT;
 159         unsigned long nr_pages = size >> PAGE_SHIFT;
 160         struct zone *zone;
 161         int ret;
 162
 163         zone = page_zone(pfn_to_page(start_pfn));
 164         ret = __remove_pages(zone, start_pfn, nr_pages);
 165         if (ret)
 166                 return ret;
 167
 168         /* Remove htab bolted mappings for this section of memory */
 169         start = (unsigned long)__va(start);
 170         ret = remove_section_mapping(start, start + size);
 171
 172         /* Ensure all vmalloc mappings are flushed in case they also
 173          * hit that section of memory
 174          */
 175         vm_unmap_aliases();
 176
 177         return ret;
 178 }
 179 #endif
 180 #endif /* CONFIG_MEMORY_HOTPLUG */
 181
 182 /*
 183  * walk_memory_resource() needs to make sure there is no holes in a given
 184  * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
 185  * Instead it maintains it in memblock.memory structures.  Walk through the
 186  * memory regions, find holes and callback for contiguous regions.
 187  */
 188 int
 189 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 190                 void *arg, int (*func)(unsigned long, unsigned long, void *))
 191 {
 192         struct memblock_region *reg;
 193         unsigned long end_pfn = start_pfn + nr_pages;
 194         unsigned long tstart, tend;
 195         int ret = -1;
 196
 197         for_each_memblock(memory, reg) {
 198                 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
 199                 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
 200                 if (tstart >= tend)
 201                         continue;
 202                 ret = (*func)(tstart, tend - tstart, arg);
 203                 if (ret)
 204                         break;
 205         }
 206         return ret;
 207 }
 208 EXPORT_SYMBOL_GPL(walk_system_ram_range);
 209
 210 #ifndef CONFIG_NEED_MULTIPLE_NODES
 211 void __init initmem_init(void)
 212 {
 213         max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
 214         min_low_pfn = MEMORY_START >> PAGE_SHIFT;
 215 #ifdef CONFIG_HIGHMEM
 216         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
 217 #endif
 218
 219         /* Place all memblock_regions in the same node and merge contiguous
 220          * memblock_regions
 221          */
 222         memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
 223
 224         /* XXX need to clip this if using highmem? */
 225         sparse_memory_present_with_active_regions(0);
 226         sparse_init();
 227 }
 228
 229 /* mark pages that don't exist as nosave */
 230 static int __init mark_nonram_nosave(void)
 231 {
 232         struct memblock_region *reg, *prev = NULL;
 233
 234         for_each_memblock(memory, reg) {
 235                 if (prev &&
 236                     memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
 237                         register_nosave_region(memblock_region_memory_end_pfn(prev),
 238                                                memblock_region_memory_base_pfn(reg));
 239                 prev = reg;
 240         }
 241         return 0;
 242 }
 243 #else /* CONFIG_NEED_MULTIPLE_NODES */
 244 static int __init mark_nonram_nosave(void)
 245 {
 246         return 0;
 247 }
 248 #endif
 249
 250 static bool zone_limits_final;
 251
 252 /*
 253  * The memory zones past TOP_ZONE are managed by generic mm code.
 254  * These should be set to zero since that's what every other
 255  * architecture does.
 256  */
 257 static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
 258         [0            ... TOP_ZONE        ] = ~0UL,
 259         [TOP_ZONE + 1 ... MAX_NR_ZONES - 1] = 0
 260 };
 261
 262 /*
 263  * Restrict the specified zone and all more restrictive zones
 264  * to be below the specified pfn.  May not be called after
 265  * paging_init().
 266  */
 267 void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
 268 {
 269         int i;
 270
 271         if (WARN_ON(zone_limits_final))
 272                 return;
 273
 274         for (i = zone; i >= 0; i--) {
 275                 if (max_zone_pfns[i] > pfn_limit)
 276                         max_zone_pfns[i] = pfn_limit;
 277         }
 278 }
 279
 280 /*
 281  * Find the least restrictive zone that is entirely below the
 282  * specified pfn limit.  Returns < 0 if no suitable zone is found.
 283  *
 284  * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
 285  * systems -- the DMA limit can be higher than any possible real pfn.
 286  */
 287 int dma_pfn_limit_to_zone(u64 pfn_limit)
 288 {
 289         int i;
 290
 291         for (i = TOP_ZONE; i >= 0; i--) {
 292                 if (max_zone_pfns[i] <= pfn_limit)
 293                         return i;
 294         }
 295
 296         return -EPERM;
 297 }
 298
 299 /*
 300  * paging_init() sets up the page tables - in fact we've already done this.
 301  */
 302 void __init paging_init(void)
 303 {
 304         unsigned long long total_ram = memblock_phys_mem_size();
 305         phys_addr_t top_of_ram = memblock_end_of_DRAM();
 306
 307 #ifdef CONFIG_PPC32
 308         unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
 309         unsigned long end = __fix_to_virt(FIX_HOLE);
 310
 311         for (; v < end; v += PAGE_SIZE)
 312                 map_page(v, 0, 0); /* XXX gross */
 313 #endif
 314
 315 #ifdef CONFIG_HIGHMEM
 316         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
 317         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 318
 319         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
 320         kmap_prot = PAGE_KERNEL;
 321 #endif /* CONFIG_HIGHMEM */
 322
 323         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
 324                (unsigned long long)top_of_ram, total_ram);
 325         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 326                (long int)((top_of_ram - total_ram) >> 20));
 327
 328 #ifdef CONFIG_HIGHMEM
 329         limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
 330 #endif
 331         limit_zone_pfn(TOP_ZONE, top_of_ram >> PAGE_SHIFT);
 332         zone_limits_final = true;
 333         free_area_init_nodes(max_zone_pfns);
 334
 335         mark_nonram_nosave();
 336 }
 337
 338 void __init mem_init(void)
 339 {
 340         /*
 341          * book3s is limited to 16 page sizes due to encoding this in
 342          * a 4-bit field for slices.
 343          */
 344         BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
 345
 346 #ifdef CONFIG_SWIOTLB
 347         swiotlb_init(0);
 348 #endif
 349
 350         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 351         set_max_mapnr(max_pfn);
 352         free_all_bootmem();
 353
 354 #ifdef CONFIG_HIGHMEM
 355         {
 356                 unsigned long pfn, highmem_mapnr;
 357
 358                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
 359                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 360                         phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
 361                         struct page *page = pfn_to_page(pfn);
 362                         if (!memblock_is_reserved(paddr))
 363                                 free_highmem_page(page);
 364                 }
 365         }
 366 #endif /* CONFIG_HIGHMEM */
 367
 368 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
 369         /*
 370          * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
 371          * functions.... do it here for the non-smp case.
 372          */
 373         per_cpu(next_tlbcam_idx, smp_processor_id()) =
 374                 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 375 #endif
 376
 377         mem_init_print_info(NULL);
 378 #ifdef CONFIG_PPC32
 379         pr_info("Kernel virtual memory layout:\n");
 380         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 381 #ifdef CONFIG_HIGHMEM
 382         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 383                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 384 #endif /* CONFIG_HIGHMEM */
 385 #ifdef CONFIG_NOT_COHERENT_CACHE
 386         pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
 387                 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
 388 #endif /* CONFIG_NOT_COHERENT_CACHE */
 389         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 390                 ioremap_bot, IOREMAP_TOP);
 391         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 392                 VMALLOC_START, VMALLOC_END);
 393 #endif /* CONFIG_PPC32 */
 394 }
 395
 396 void free_initmem(void)
 397 {
 398         ppc_md.progress = ppc_printk_progress;
 399         free_initmem_default(POISON_FREE_INITMEM);
 400 }
 401
 402 #ifdef CONFIG_BLK_DEV_INITRD
 403 void __init free_initrd_mem(unsigned long start, unsigned long end)
 404 {
 405         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 406 }
 407 #endif
 408
 409 /*
 410  * This is called when a page has been modified by the kernel.
 411  * It just marks the page as not i-cache clean.  We do the i-cache
 412  * flush later when the page is given to a user process, if necessary.
 413  */
 414 void flush_dcache_page(struct page *page)
 415 {
 416         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 417                 return;
 418         /* avoid an atomic op if possible */
 419         if (test_bit(PG_arch_1, &page->flags))
 420                 clear_bit(PG_arch_1, &page->flags);
 421 }
 422 EXPORT_SYMBOL(flush_dcache_page);
 423
 424 void flush_dcache_icache_page(struct page *page)
 425 {
 426 #ifdef CONFIG_HUGETLB_PAGE
 427         if (PageCompound(page)) {
 428                 flush_dcache_icache_hugepage(page);
 429                 return;
 430         }
 431 #endif
 432 #if defined(CONFIG_8xx) || defined(CONFIG_PPC64)
 433         /* On 8xx there is no need to kmap since highmem is not supported */
 434         __flush_dcache_icache(page_address(page));
 435 #else
 436         if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
 437                 void *start = kmap_atomic(page);
 438                 __flush_dcache_icache(start);
 439                 kunmap_atomic(start);
 440         } else {
 441                 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 442         }
 443 #endif
 444 }
 445 EXPORT_SYMBOL(flush_dcache_icache_page);
 446
 447 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 448 {
 449         clear_page(page);
 450
 451         /*
 452          * We shouldn't have to do this, but some versions of glibc
 453          * require it (ld.so assumes zero filled pages are icache clean)
 454          * - Anton
 455          */
 456         flush_dcache_page(pg);
 457 }
 458 EXPORT_SYMBOL(clear_user_page);
 459
 460 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 461                     struct page *pg)
 462 {
 463         copy_page(vto, vfrom);
 464
 465         /*
 466          * We should be able to use the following optimisation, however
 467          * there are two problems.
 468          * Firstly a bug in some versions of binutils meant PLT sections
 469          * were not marked executable.
 470          * Secondly the first word in the GOT section is blrl, used
 471          * to establish the GOT address. Until recently the GOT was
 472          * not marked executable.
 473          * - Anton
 474          */
 475 #if 0
 476         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 477                 return;
 478 #endif
 479
 480         flush_dcache_page(pg);
 481 }
 482
 483 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 484                              unsigned long addr, int len)
 485 {
 486         unsigned long maddr;
 487
 488         maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 489         flush_icache_range(maddr, maddr + len);
 490         kunmap(page);
 491 }
 492 EXPORT_SYMBOL(flush_icache_user_range);
 493
 494 /*
 495  * This is called at the end of handling a user page fault, when the
 496  * fault has been handled by updating a PTE in the linux page tables.
 497  * We use it to preload an HPTE into the hash table corresponding to
 498  * the updated linux PTE.
 499  *
 500  * This must always be called with the pte lock held.
 501  */
 502 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 503                       pte_t *ptep)
 504 {
 505 #ifdef CONFIG_PPC_STD_MMU
 506         /*
 507          * We don't need to worry about _PAGE_PRESENT here because we are
 508          * called with either mm->page_table_lock held or ptl lock held
 509          */
 510         unsigned long access, trap;
 511
 512         if (radix_enabled())
 513                 return;
 514
 515         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 516         if (!pte_young(*ptep) || address >= TASK_SIZE)
 517                 return;
 518
 519         /* We try to figure out if we are coming from an instruction
 520          * access fault and pass that down to __hash_page so we avoid
 521          * double-faulting on execution of fresh text. We have to test
 522          * for regs NULL since init will get here first thing at boot
 523          *
 524          * We also avoid filling the hash if not coming from a fault
 525          */
 526
 527         trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
 528         switch (trap) {
 529         case 0x300:
 530                 access = 0UL;
 531                 break;
 532         case 0x400:
 533                 access = _PAGE_EXEC;
 534                 break;
 535         default:
 536                 return;
 537         }
 538
 539         hash_preload(vma->vm_mm, address, access, trap);
 540 #endif /* CONFIG_PPC_STD_MMU */
 541 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
 542         && defined(CONFIG_HUGETLB_PAGE)
 543         if (is_vm_hugetlb_page(vma))
 544                 book3e_hugetlb_preload(vma, address, *ptep);
 545 #endif
 546 }
 547
 548 /*
 549  * System memory should not be in /proc/iomem but various tools expect it
 550  * (eg kdump).
 551  */
 552 static int __init add_system_ram_resources(void)
 553 {
 554         struct memblock_region *reg;
 555
 556         for_each_memblock(memory, reg) {
 557                 struct resource *res;
 558                 unsigned long base = reg->base;
 559                 unsigned long size = reg->size;
 560
 561                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 562                 WARN_ON(!res);
 563
 564                 if (res) {
 565                         res->name = "System RAM";
 566                         res->start = base;
 567                         res->end = base + size - 1;
 568                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 569                         WARN_ON(request_resource(&iomem_resource, res) < 0);
 570                 }
 571         }
 572
 573         return 0;
 574 }
 575 subsys_initcall(add_system_ram_resources);
 576
 577 #ifdef CONFIG_STRICT_DEVMEM
 578 /*
 579  * devmem_is_allowed(): check to see if /dev/mem access to a certain address
 580  * is valid. The argument is a physical page number.
 581  *
 582  * Access has to be given to non-kernel-ram areas as well, these contain the
 583  * PCI mmio resources as well as potential bios/acpi data regions.
 584  */
 585 int devmem_is_allowed(unsigned long pfn)
 586 {
 587         if (page_is_rtas_user_buf(pfn))
 588                 return 1;
 589         if (iomem_is_exclusive(PFN_PHYS(pfn)))
 590                 return 0;
 591         if (!page_is_ram(pfn))
 592                 return 1;
 593         return 0;
 594 }
 595 #endif /* CONFIG_STRICT_DEVMEM */