arch/ia64/mm/init.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Initialize MMU support.
   4  *
   5  * Copyright (C) 1998-2003 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10
  11 #include <linux/dma-map-ops.h>
  12 #include <linux/dmar.h>
  13 #include <linux/efi.h>
  14 #include <linux/elf.h>
  15 #include <linux/memblock.h>
  16 #include <linux/mm.h>
  17 #include <linux/sched/signal.h>
  18 #include <linux/mmzone.h>
  19 #include <linux/module.h>
  20 #include <linux/personality.h>
  21 #include <linux/reboot.h>
  22 #include <linux/slab.h>
  23 #include <linux/swap.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/bitops.h>
  26 #include <linux/kexec.h>
  27 #include <linux/swiotlb.h>
  28
  29 #include <asm/dma.h>
  30 #include <asm/efi.h>
  31 #include <asm/io.h>
  32 #include <asm/numa.h>
  33 #include <asm/patch.h>
  34 #include <asm/pgalloc.h>
  35 #include <asm/sal.h>
  36 #include <asm/sections.h>
  37 #include <asm/tlb.h>
  38 #include <linux/uaccess.h>
  39 #include <asm/unistd.h>
  40 #include <asm/mca.h>
  41
  42 extern void ia64_tlb_init (void);
  43
  44 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
  45
  46 #ifdef CONFIG_VIRTUAL_MEM_MAP
  47 unsigned long VMALLOC_END = VMALLOC_END_INIT;
  48 EXPORT_SYMBOL(VMALLOC_END);
  49 struct page *vmem_map;
  50 EXPORT_SYMBOL(vmem_map);
  51 #endif
  52
  53 struct page *zero_page_memmap_ptr;      /* map entry for zero page */
  54 EXPORT_SYMBOL(zero_page_memmap_ptr);
  55
  56 void
  57 __ia64_sync_icache_dcache (pte_t pte)
  58 {
  59         unsigned long addr;
  60         struct page *page;
  61
  62         page = pte_page(pte);
  63         addr = (unsigned long) page_address(page);
  64
  65         if (test_bit(PG_arch_1, &page->flags))
  66                 return;                         /* i-cache is already coherent with d-cache */
  67
  68         flush_icache_range(addr, addr + page_size(page));
  69         set_bit(PG_arch_1, &page->flags);       /* mark page as clean */
  70 }
  71
  72 /*
  73  * Since DMA is i-cache coherent, any (complete) pages that were written via
  74  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
  75  * flush them when they get mapped into an executable vm-area.
  76  */
  77 void arch_dma_mark_clean(phys_addr_t paddr, size_t size)
  78 {
  79         unsigned long pfn = PHYS_PFN(paddr);
  80
  81         do {
  82                 set_bit(PG_arch_1, &pfn_to_page(pfn)->flags);
  83         } while (++pfn <= PHYS_PFN(paddr + size - 1));
  84 }
  85
  86 inline void
  87 ia64_set_rbs_bot (void)
  88 {
  89         unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
  90
  91         if (stack_size > MAX_USER_STACK_SIZE)
  92                 stack_size = MAX_USER_STACK_SIZE;
  93         current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
  94 }
  95
  96 /*
  97  * This performs some platform-dependent address space initialization.
  98  * On IA-64, we want to setup the VM area for the register backing
  99  * store (which grows upwards) and install the gateway page which is
 100  * used for signal trampolines, etc.
 101  */
 102 void
 103 ia64_init_addr_space (void)
 104 {
 105         struct vm_area_struct *vma;
 106
 107         ia64_set_rbs_bot();
 108
 109         /*
 110          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
 111          * the problem.  When the process attempts to write to the register backing store
 112          * for the first time, it will get a SEGFAULT in this case.
 113          */
 114         vma = vm_area_alloc(current->mm);
 115         if (vma) {
 116                 vma_set_anonymous(vma);
 117                 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
 118                 vma->vm_end = vma->vm_start + PAGE_SIZE;
 119                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
 120                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
 121                 mmap_write_lock(current->mm);
 122                 if (insert_vm_struct(current->mm, vma)) {
 123                         mmap_write_unlock(current->mm);
 124                         vm_area_free(vma);
 125                         return;
 126                 }
 127                 mmap_write_unlock(current->mm);
 128         }
 129
 130         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
 131         if (!(current->personality & MMAP_PAGE_ZERO)) {
 132                 vma = vm_area_alloc(current->mm);
 133                 if (vma) {
 134                         vma_set_anonymous(vma);
 135                         vma->vm_end = PAGE_SIZE;
 136                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
 137                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |
 138                                         VM_DONTEXPAND | VM_DONTDUMP;
 139                         mmap_write_lock(current->mm);
 140                         if (insert_vm_struct(current->mm, vma)) {
 141                                 mmap_write_unlock(current->mm);
 142                                 vm_area_free(vma);
 143                                 return;
 144                         }
 145                         mmap_write_unlock(current->mm);
 146                 }
 147         }
 148 }
 149
 150 void
 151 free_initmem (void)
 152 {
 153         free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end),
 154                            -1, "unused kernel");
 155 }
 156
 157 void __init
 158 free_initrd_mem (unsigned long start, unsigned long end)
 159 {
 160         /*
 161          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
 162          * Thus EFI and the kernel may have different page sizes. It is
 163          * therefore possible to have the initrd share the same page as
 164          * the end of the kernel (given current setup).
 165          *
 166          * To avoid freeing/using the wrong page (kernel sized) we:
 167          *      - align up the beginning of initrd
 168          *      - align down the end of initrd
 169          *
 170          *  |             |
 171          *  |=============| a000
 172          *  |             |
 173          *  |             |
 174          *  |             | 9000
 175          *  |/////////////|
 176          *  |/////////////|
 177          *  |=============| 8000
 178          *  |///INITRD////|
 179          *  |/////////////|
 180          *  |/////////////| 7000
 181          *  |             |
 182          *  |KKKKKKKKKKKKK|
 183          *  |=============| 6000
 184          *  |KKKKKKKKKKKKK|
 185          *  |KKKKKKKKKKKKK|
 186          *  K=kernel using 8KB pages
 187          *
 188          * In this example, we must free page 8000 ONLY. So we must align up
 189          * initrd_start and keep initrd_end as is.
 190          */
 191         start = PAGE_ALIGN(start);
 192         end = end & PAGE_MASK;
 193
 194         if (start < end)
 195                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
 196
 197         for (; start < end; start += PAGE_SIZE) {
 198                 if (!virt_addr_valid(start))
 199                         continue;
 200                 free_reserved_page(virt_to_page(start));
 201         }
 202 }
 203
 204 /*
 205  * This installs a clean page in the kernel's page table.
 206  */
 207 static struct page * __init
 208 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
 209 {
 210         pgd_t *pgd;
 211         p4d_t *p4d;
 212         pud_t *pud;
 213         pmd_t *pmd;
 214         pte_t *pte;
 215
 216         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
 217
 218         {
 219                 p4d = p4d_alloc(&init_mm, pgd, address);
 220                 if (!p4d)
 221                         goto out;
 222                 pud = pud_alloc(&init_mm, p4d, address);
 223                 if (!pud)
 224                         goto out;
 225                 pmd = pmd_alloc(&init_mm, pud, address);
 226                 if (!pmd)
 227                         goto out;
 228                 pte = pte_alloc_kernel(pmd, address);
 229                 if (!pte)
 230                         goto out;
 231                 if (!pte_none(*pte))
 232                         goto out;
 233                 set_pte(pte, mk_pte(page, pgprot));
 234         }
 235   out:
 236         /* no need for flush_tlb */
 237         return page;
 238 }
 239
 240 static void __init
 241 setup_gate (void)
 242 {
 243         struct page *page;
 244
 245         /*
 246          * Map the gate page twice: once read-only to export the ELF
 247          * headers etc. and once execute-only page to enable
 248          * privilege-promotion via "epc":
 249          */
 250         page = virt_to_page(ia64_imva(__start_gate_section));
 251         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
 252 #ifdef HAVE_BUGGY_SEGREL
 253         page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
 254         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
 255 #else
 256         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
 257         /* Fill in the holes (if any) with read-only zero pages: */
 258         {
 259                 unsigned long addr;
 260
 261                 for (addr = GATE_ADDR + PAGE_SIZE;
 262                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
 263                      addr += PAGE_SIZE)
 264                 {
 265                         put_kernel_page(ZERO_PAGE(0), addr,
 266                                         PAGE_READONLY);
 267                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
 268                                         PAGE_READONLY);
 269                 }
 270         }
 271 #endif
 272         ia64_patch_gate();
 273 }
 274
 275 static struct vm_area_struct gate_vma;
 276
 277 static int __init gate_vma_init(void)
 278 {
 279         vma_init(&gate_vma, NULL);
 280         gate_vma.vm_start = FIXADDR_USER_START;
 281         gate_vma.vm_end = FIXADDR_USER_END;
 282         gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
 283         gate_vma.vm_page_prot = __P101;
 284
 285         return 0;
 286 }
 287 __initcall(gate_vma_init);
 288
 289 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
 290 {
 291         return &gate_vma;
 292 }
 293
 294 int in_gate_area_no_mm(unsigned long addr)
 295 {
 296         if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
 297                 return 1;
 298         return 0;
 299 }
 300
 301 int in_gate_area(struct mm_struct *mm, unsigned long addr)
 302 {
 303         return in_gate_area_no_mm(addr);
 304 }
 305
 306 void ia64_mmu_init(void *my_cpu_data)
 307 {
 308         unsigned long pta, impl_va_bits;
 309         extern void tlb_init(void);
 310
 311 #ifdef CONFIG_DISABLE_VHPT
 312 #       define VHPT_ENABLE_BIT  0
 313 #else
 314 #       define VHPT_ENABLE_BIT  1
 315 #endif
 316
 317         /*
 318          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
 319          * address space.  The IA-64 architecture guarantees that at least 50 bits of
 320          * virtual address space are implemented but if we pick a large enough page size
 321          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
 322          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
 323          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
 324          * problem in practice.  Alternatively, we could truncate the top of the mapped
 325          * address space to not permit mappings that would overlap with the VMLPT.
 326          * --davidm 00/12/06
 327          */
 328 #       define pte_bits                 3
 329 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
 330         /*
 331          * The virtual page table has to cover the entire implemented address space within
 332          * a region even though not all of this space may be mappable.  The reason for
 333          * this is that the Access bit and Dirty bit fault handlers perform
 334          * non-speculative accesses to the virtual page table, so the address range of the
 335          * virtual page table itself needs to be covered by virtual page table.
 336          */
 337 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
 338 #       define POW2(n)                  (1ULL << (n))
 339
 340         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
 341
 342         if (impl_va_bits < 51 || impl_va_bits > 61)
 343                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
 344         /*
 345          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
 346          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
 347          * the test makes sure that our mapped space doesn't overlap the
 348          * unimplemented hole in the middle of the region.
 349          */
 350         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
 351             (mapped_space_bits > impl_va_bits - 1))
 352                 panic("Cannot build a big enough virtual-linear page table"
 353                       " to cover mapped address space.\n"
 354                       " Try using a smaller page size.\n");
 355
 356
 357         /* place the VMLPT at the end of each page-table mapped region: */
 358         pta = POW2(61) - POW2(vmlpt_bits);
 359
 360         /*
 361          * Set the (virtually mapped linear) page table address.  Bit
 362          * 8 selects between the short and long format, bits 2-7 the
 363          * size of the table, and bit 0 whether the VHPT walker is
 364          * enabled.
 365          */
 366         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
 367
 368         ia64_tlb_init();
 369
 370 #ifdef  CONFIG_HUGETLB_PAGE
 371         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
 372         ia64_srlz_d();
 373 #endif
 374 }
 375
 376 #ifdef CONFIG_VIRTUAL_MEM_MAP
 377 int vmemmap_find_next_valid_pfn(int node, int i)
 378 {
 379         unsigned long end_address, hole_next_pfn;
 380         unsigned long stop_address;
 381         pg_data_t *pgdat = NODE_DATA(node);
 382
 383         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
 384         end_address = PAGE_ALIGN(end_address);
 385         stop_address = (unsigned long) &vmem_map[pgdat_end_pfn(pgdat)];
 386
 387         do {
 388                 pgd_t *pgd;
 389                 p4d_t *p4d;
 390                 pud_t *pud;
 391                 pmd_t *pmd;
 392                 pte_t *pte;
 393
 394                 pgd = pgd_offset_k(end_address);
 395                 if (pgd_none(*pgd)) {
 396                         end_address += PGDIR_SIZE;
 397                         continue;
 398                 }
 399
 400                 p4d = p4d_offset(pgd, end_address);
 401                 if (p4d_none(*p4d)) {
 402                         end_address += P4D_SIZE;
 403                         continue;
 404                 }
 405
 406                 pud = pud_offset(p4d, end_address);
 407                 if (pud_none(*pud)) {
 408                         end_address += PUD_SIZE;
 409                         continue;
 410                 }
 411
 412                 pmd = pmd_offset(pud, end_address);
 413                 if (pmd_none(*pmd)) {
 414                         end_address += PMD_SIZE;
 415                         continue;
 416                 }
 417
 418                 pte = pte_offset_kernel(pmd, end_address);
 419 retry_pte:
 420                 if (pte_none(*pte)) {
 421                         end_address += PAGE_SIZE;
 422                         pte++;
 423                         if ((end_address < stop_address) &&
 424                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
 425                                 goto retry_pte;
 426                         continue;
 427                 }
 428                 /* Found next valid vmem_map page */
 429                 break;
 430         } while (end_address < stop_address);
 431
 432         end_address = min(end_address, stop_address);
 433         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
 434         hole_next_pfn = end_address / sizeof(struct page);
 435         return hole_next_pfn - pgdat->node_start_pfn;
 436 }
 437
 438 int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
 439 {
 440         unsigned long address, start_page, end_page;
 441         struct page *map_start, *map_end;
 442         int node;
 443         pgd_t *pgd;
 444         p4d_t *p4d;
 445         pud_t *pud;
 446         pmd_t *pmd;
 447         pte_t *pte;
 448
 449         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 450         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 451
 452         start_page = (unsigned long) map_start & PAGE_MASK;
 453         end_page = PAGE_ALIGN((unsigned long) map_end);
 454         node = paddr_to_nid(__pa(start));
 455
 456         for (address = start_page; address < end_page; address += PAGE_SIZE) {
 457                 pgd = pgd_offset_k(address);
 458                 if (pgd_none(*pgd)) {
 459                         p4d = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
 460                         if (!p4d)
 461                                 goto err_alloc;
 462                         pgd_populate(&init_mm, pgd, p4d);
 463                 }
 464                 p4d = p4d_offset(pgd, address);
 465
 466                 if (p4d_none(*p4d)) {
 467                         pud = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
 468                         if (!pud)
 469                                 goto err_alloc;
 470                         p4d_populate(&init_mm, p4d, pud);
 471                 }
 472                 pud = pud_offset(p4d, address);
 473
 474                 if (pud_none(*pud)) {
 475                         pmd = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
 476                         if (!pmd)
 477                                 goto err_alloc;
 478                         pud_populate(&init_mm, pud, pmd);
 479                 }
 480                 pmd = pmd_offset(pud, address);
 481
 482                 if (pmd_none(*pmd)) {
 483                         pte = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
 484                         if (!pte)
 485                                 goto err_alloc;
 486                         pmd_populate_kernel(&init_mm, pmd, pte);
 487                 }
 488                 pte = pte_offset_kernel(pmd, address);
 489
 490                 if (pte_none(*pte)) {
 491                         void *page = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE,
 492                                                          node);
 493                         if (!page)
 494                                 goto err_alloc;
 495                         set_pte(pte, pfn_pte(__pa(page) >> PAGE_SHIFT,
 496                                              PAGE_KERNEL));
 497                 }
 498         }
 499         return 0;
 500
 501 err_alloc:
 502         panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d\n",
 503               __func__, PAGE_SIZE, PAGE_SIZE, node);
 504         return -ENOMEM;
 505 }
 506
 507 struct memmap_init_callback_data {
 508         struct page *start;
 509         struct page *end;
 510         int nid;
 511         unsigned long zone;
 512 };
 513
 514 static int __meminit
 515 virtual_memmap_init(u64 start, u64 end, void *arg)
 516 {
 517         struct memmap_init_callback_data *args;
 518         struct page *map_start, *map_end;
 519
 520         args = (struct memmap_init_callback_data *) arg;
 521         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
 522         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
 523
 524         if (map_start < args->start)
 525                 map_start = args->start;
 526         if (map_end > args->end)
 527                 map_end = args->end;
 528
 529         /*
 530          * We have to initialize "out of bounds" struct page elements that fit completely
 531          * on the same pages that were allocated for the "in bounds" elements because they
 532          * may be referenced later (and found to be "reserved").
 533          */
 534         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
 535         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
 536                     / sizeof(struct page));
 537
 538         if (map_start < map_end)
 539                 memmap_init_zone((unsigned long)(map_end - map_start),
 540                                  args->nid, args->zone, page_to_pfn(map_start),
 541                                  MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
 542         return 0;
 543 }
 544
 545 void __meminit
 546 memmap_init (unsigned long size, int nid, unsigned long zone,
 547              unsigned long start_pfn)
 548 {
 549         if (!vmem_map) {
 550                 memmap_init_zone(size, nid, zone, start_pfn,
 551                                  MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
 552         } else {
 553                 struct page *start;
 554                 struct memmap_init_callback_data args;
 555
 556                 start = pfn_to_page(start_pfn);
 557                 args.start = start;
 558                 args.end = start + size;
 559                 args.nid = nid;
 560                 args.zone = zone;
 561
 562                 efi_memmap_walk(virtual_memmap_init, &args);
 563         }
 564 }
 565
 566 int
 567 ia64_pfn_valid (unsigned long pfn)
 568 {
 569         char byte;
 570         struct page *pg = pfn_to_page(pfn);
 571
 572         return     (__get_user(byte, (char __user *) pg) == 0)
 573                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
 574                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
 575 }
 576 EXPORT_SYMBOL(ia64_pfn_valid);
 577
 578 #endif /* CONFIG_VIRTUAL_MEM_MAP */
 579
 580 int __init register_active_ranges(u64 start, u64 len, int nid)
 581 {
 582         u64 end = start + len;
 583
 584 #ifdef CONFIG_KEXEC
 585         if (start > crashk_res.start && start < crashk_res.end)
 586                 start = crashk_res.end;
 587         if (end > crashk_res.start && end < crashk_res.end)
 588                 end = crashk_res.start;
 589 #endif
 590
 591         if (start < end)
 592                 memblock_add_node(__pa(start), end - start, nid);
 593         return 0;
 594 }
 595
 596 int
 597 find_max_min_low_pfn (u64 start, u64 end, void *arg)
 598 {
 599         unsigned long pfn_start, pfn_end;
 600 #ifdef CONFIG_FLATMEM
 601         pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
 602         pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
 603 #else
 604         pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
 605         pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
 606 #endif
 607         min_low_pfn = min(min_low_pfn, pfn_start);
 608         max_low_pfn = max(max_low_pfn, pfn_end);
 609         return 0;
 610 }
 611
 612 /*
 613  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
 614  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
 615  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
 616  * useful for performance testing, but conceivably could also come in handy for debugging
 617  * purposes.
 618  */
 619
 620 static int nolwsys __initdata;
 621
 622 static int __init
 623 nolwsys_setup (char *s)
 624 {
 625         nolwsys = 1;
 626         return 1;
 627 }
 628
 629 __setup("nolwsys", nolwsys_setup);
 630
 631 void __init
 632 mem_init (void)
 633 {
 634         int i;
 635
 636         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
 637         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
 638         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
 639
 640         /*
 641          * This needs to be called _after_ the command line has been parsed but
 642          * _before_ any drivers that may need the PCI DMA interface are
 643          * initialized or bootmem has been freed.
 644          */
 645 #ifdef CONFIG_INTEL_IOMMU
 646         detect_intel_iommu();
 647         if (!iommu_detected)
 648 #endif
 649 #ifdef CONFIG_SWIOTLB
 650                 swiotlb_init(1);
 651 #endif
 652
 653 #ifdef CONFIG_FLATMEM
 654         BUG_ON(!mem_map);
 655 #endif
 656
 657         set_max_mapnr(max_low_pfn);
 658         high_memory = __va(max_low_pfn * PAGE_SIZE);
 659         memblock_free_all();
 660         mem_init_print_info(NULL);
 661
 662         /*
 663          * For fsyscall entrpoints with no light-weight handler, use the ordinary
 664          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
 665          * code can tell them apart.
 666          */
 667         for (i = 0; i < NR_syscalls; ++i) {
 668                 extern unsigned long fsyscall_table[NR_syscalls];
 669                 extern unsigned long sys_call_table[NR_syscalls];
 670
 671                 if (!fsyscall_table[i] || nolwsys)
 672                         fsyscall_table[i] = sys_call_table[i] | 1;
 673         }
 674         setup_gate();
 675 }
 676
 677 #ifdef CONFIG_MEMORY_HOTPLUG
 678 int arch_add_memory(int nid, u64 start, u64 size,
 679                     struct mhp_params *params)
 680 {
 681         unsigned long start_pfn = start >> PAGE_SHIFT;
 682         unsigned long nr_pages = size >> PAGE_SHIFT;
 683         int ret;
 684
 685         if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
 686                 return -EINVAL;
 687
 688         ret = __add_pages(nid, start_pfn, nr_pages, params);
 689         if (ret)
 690                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
 691                        __func__,  ret);
 692
 693         return ret;
 694 }
 695
 696 void arch_remove_memory(int nid, u64 start, u64 size,
 697                         struct vmem_altmap *altmap)
 698 {
 699         unsigned long start_pfn = start >> PAGE_SHIFT;
 700         unsigned long nr_pages = size >> PAGE_SHIFT;
 701
 702         __remove_pages(start_pfn, nr_pages, altmap);
 703 }
 704 #endif