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