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