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