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 #include <linux/memremap.h>
  40
  41 #include <asm/pgalloc.h>
  42 #include <asm/prom.h>
  43 #include <asm/io.h>
  44 #include <asm/mmu_context.h>
  45 #include <asm/pgtable.h>
  46 #include <asm/mmu.h>
  47 #include <asm/smp.h>
  48 #include <asm/machdep.h>
  49 #include <asm/btext.h>
  50 #include <asm/tlb.h>
  51 #include <asm/sections.h>
  52 #include <asm/sparsemem.h>
  53 #include <asm/vdso.h>
  54 #include <asm/fixmap.h>
  55 #include <asm/swiotlb.h>
  56 #include <asm/rtas.h>
  57
  58 #include "mmu_decl.h"
  59
  60 #ifndef CPU_FTR_COHERENT_ICACHE
  61 #define CPU_FTR_COHERENT_ICACHE 0       /* XXX for now */
  62 #define CPU_FTR_NOEXECUTE       0
  63 #endif
  64
  65 unsigned long long memory_limit;
  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 static bool zone_limits_final;
 250
 251 /*
 252  * The memory zones past TOP_ZONE are managed by generic mm code.
 253  * These should be set to zero since that's what every other
 254  * architecture does.
 255  */
 256 static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
 257         [0            ... TOP_ZONE        ] = ~0UL,
 258         [TOP_ZONE + 1 ... MAX_NR_ZONES - 1] = 0
 259 };
 260
 261 /*
 262  * Restrict the specified zone and all more restrictive zones
 263  * to be below the specified pfn.  May not be called after
 264  * paging_init().
 265  */
 266 void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
 267 {
 268         int i;
 269
 270         if (WARN_ON(zone_limits_final))
 271                 return;
 272
 273         for (i = zone; i >= 0; i--) {
 274                 if (max_zone_pfns[i] > pfn_limit)
 275                         max_zone_pfns[i] = pfn_limit;
 276         }
 277 }
 278
 279 /*
 280  * Find the least restrictive zone that is entirely below the
 281  * specified pfn limit.  Returns < 0 if no suitable zone is found.
 282  *
 283  * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
 284  * systems -- the DMA limit can be higher than any possible real pfn.
 285  */
 286 int dma_pfn_limit_to_zone(u64 pfn_limit)
 287 {
 288         int i;
 289
 290         for (i = TOP_ZONE; i >= 0; i--) {
 291                 if (max_zone_pfns[i] <= pfn_limit)
 292                         return i;
 293         }
 294
 295         return -EPERM;
 296 }
 297
 298 /*
 299  * paging_init() sets up the page tables - in fact we've already done this.
 300  */
 301 void __init paging_init(void)
 302 {
 303         unsigned long long total_ram = memblock_phys_mem_size();
 304         phys_addr_t top_of_ram = memblock_end_of_DRAM();
 305
 306 #ifdef CONFIG_PPC32
 307         unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
 308         unsigned long end = __fix_to_virt(FIX_HOLE);
 309
 310         for (; v < end; v += PAGE_SIZE)
 311                 map_kernel_page(v, 0, 0); /* XXX gross */
 312 #endif
 313
 314 #ifdef CONFIG_HIGHMEM
 315         map_kernel_page(PKMAP_BASE, 0, 0);      /* XXX gross */
 316         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 317
 318         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
 319         kmap_prot = PAGE_KERNEL;
 320 #endif /* CONFIG_HIGHMEM */
 321
 322         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
 323                (unsigned long long)top_of_ram, total_ram);
 324         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 325                (long int)((top_of_ram - total_ram) >> 20));
 326
 327 #ifdef CONFIG_HIGHMEM
 328         limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
 329 #endif
 330         limit_zone_pfn(TOP_ZONE, top_of_ram >> PAGE_SHIFT);
 331         zone_limits_final = true;
 332         free_area_init_nodes(max_zone_pfns);
 333
 334         mark_nonram_nosave();
 335 }
 336
 337 void __init mem_init(void)
 338 {
 339         /*
 340          * book3s is limited to 16 page sizes due to encoding this in
 341          * a 4-bit field for slices.
 342          */
 343         BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
 344
 345 #ifdef CONFIG_SWIOTLB
 346         swiotlb_init(0);
 347 #endif
 348
 349         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 350         set_max_mapnr(max_pfn);
 351         free_all_bootmem();
 352
 353 #ifdef CONFIG_HIGHMEM
 354         {
 355                 unsigned long pfn, highmem_mapnr;
 356
 357                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
 358                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 359                         phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
 360                         struct page *page = pfn_to_page(pfn);
 361                         if (!memblock_is_reserved(paddr))
 362                                 free_highmem_page(page);
 363                 }
 364         }
 365 #endif /* CONFIG_HIGHMEM */
 366
 367 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
 368         /*
 369          * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
 370          * functions.... do it here for the non-smp case.
 371          */
 372         per_cpu(next_tlbcam_idx, smp_processor_id()) =
 373                 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 374 #endif
 375
 376         mem_init_print_info(NULL);
 377 #ifdef CONFIG_PPC32
 378         pr_info("Kernel virtual memory layout:\n");
 379         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 380 #ifdef CONFIG_HIGHMEM
 381         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 382                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 383 #endif /* CONFIG_HIGHMEM */
 384 #ifdef CONFIG_NOT_COHERENT_CACHE
 385         pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
 386                 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
 387 #endif /* CONFIG_NOT_COHERENT_CACHE */
 388         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 389                 ioremap_bot, IOREMAP_TOP);
 390         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 391                 VMALLOC_START, VMALLOC_END);
 392 #endif /* CONFIG_PPC32 */
 393 }
 394
 395 void free_initmem(void)
 396 {
 397         ppc_md.progress = ppc_printk_progress;
 398         mark_initmem_nx();
 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_PPC_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                 prefetch((void *)address);
 514                 return;
 515         }
 516
 517         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 518         if (!pte_young(*ptep) || address >= TASK_SIZE)
 519                 return;
 520
 521         /* We try to figure out if we are coming from an instruction
 522          * access fault and pass that down to __hash_page so we avoid
 523          * double-faulting on execution of fresh text. We have to test
 524          * for regs NULL since init will get here first thing at boot
 525          *
 526          * We also avoid filling the hash if not coming from a fault
 527          */
 528
 529         trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
 530         switch (trap) {
 531         case 0x300:
 532                 access = 0UL;
 533                 break;
 534         case 0x400:
 535                 access = _PAGE_EXEC;
 536                 break;
 537         default:
 538                 return;
 539         }
 540
 541         hash_preload(vma->vm_mm, address, access, trap);
 542 #endif /* CONFIG_PPC_STD_MMU */
 543 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
 544         && defined(CONFIG_HUGETLB_PAGE)
 545         if (is_vm_hugetlb_page(vma))
 546                 book3e_hugetlb_preload(vma, address, *ptep);
 547 #endif
 548 }
 549
 550 /*
 551  * System memory should not be in /proc/iomem but various tools expect it
 552  * (eg kdump).
 553  */
 554 static int __init add_system_ram_resources(void)
 555 {
 556         struct memblock_region *reg;
 557
 558         for_each_memblock(memory, reg) {
 559                 struct resource *res;
 560                 unsigned long base = reg->base;
 561                 unsigned long size = reg->size;
 562
 563                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 564                 WARN_ON(!res);
 565
 566                 if (res) {
 567                         res->name = "System RAM";
 568                         res->start = base;
 569                         res->end = base + size - 1;
 570                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 571                         WARN_ON(request_resource(&iomem_resource, res) < 0);
 572                 }
 573         }
 574
 575         return 0;
 576 }
 577 subsys_initcall(add_system_ram_resources);
 578
 579 #ifdef CONFIG_STRICT_DEVMEM
 580 /*
 581  * devmem_is_allowed(): check to see if /dev/mem access to a certain address
 582  * is valid. The argument is a physical page number.
 583  *
 584  * Access has to be given to non-kernel-ram areas as well, these contain the
 585  * PCI mmio resources as well as potential bios/acpi data regions.
 586  */
 587 int devmem_is_allowed(unsigned long pfn)
 588 {
 589         if (page_is_rtas_user_buf(pfn))
 590                 return 1;
 591         if (iomem_is_exclusive(PFN_PHYS(pfn)))
 592                 return 0;
 593         if (!page_is_ram(pfn))
 594                 return 1;
 595         return 0;
 596 }
 597 #endif /* CONFIG_STRICT_DEVMEM */