mm, memory_hotplug: add nid parameter to arch_remove_memory
[sfrench/cifs-2.6.git] / 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/efi.h>
12 #include <linux/elf.h>
13 #include <linux/memblock.h>
14 #include <linux/mm.h>
15 #include <linux/sched/signal.h>
16 #include <linux/mmzone.h>
17 #include <linux/module.h>
18 #include <linux/personality.h>
19 #include <linux/reboot.h>
20 #include <linux/slab.h>
21 #include <linux/swap.h>
22 #include <linux/proc_fs.h>
23 #include <linux/bitops.h>
24 #include <linux/kexec.h>
25
26 #include <asm/dma.h>
27 #include <asm/io.h>
28 #include <asm/machvec.h>
29 #include <asm/numa.h>
30 #include <asm/patch.h>
31 #include <asm/pgalloc.h>
32 #include <asm/sal.h>
33 #include <asm/sections.h>
34 #include <asm/tlb.h>
35 #include <linux/uaccess.h>
36 #include <asm/unistd.h>
37 #include <asm/mca.h>
38
39 extern void ia64_tlb_init (void);
40
41 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
42
43 #ifdef CONFIG_VIRTUAL_MEM_MAP
44 unsigned long VMALLOC_END = VMALLOC_END_INIT;
45 EXPORT_SYMBOL(VMALLOC_END);
46 struct page *vmem_map;
47 EXPORT_SYMBOL(vmem_map);
48 #endif
49
50 struct page *zero_page_memmap_ptr;      /* map entry for zero page */
51 EXPORT_SYMBOL(zero_page_memmap_ptr);
52
53 void
54 __ia64_sync_icache_dcache (pte_t pte)
55 {
56         unsigned long addr;
57         struct page *page;
58
59         page = pte_page(pte);
60         addr = (unsigned long) page_address(page);
61
62         if (test_bit(PG_arch_1, &page->flags))
63                 return;                         /* i-cache is already coherent with d-cache */
64
65         flush_icache_range(addr, addr + (PAGE_SIZE << compound_order(page)));
66         set_bit(PG_arch_1, &page->flags);       /* mark page as clean */
67 }
68
69 /*
70  * Since DMA is i-cache coherent, any (complete) pages that were written via
71  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
72  * flush them when they get mapped into an executable vm-area.
73  */
74 void
75 dma_mark_clean(void *addr, size_t size)
76 {
77         unsigned long pg_addr, end;
78
79         pg_addr = PAGE_ALIGN((unsigned long) addr);
80         end = (unsigned long) addr + size;
81         while (pg_addr + PAGE_SIZE <= end) {
82                 struct page *page = virt_to_page(pg_addr);
83                 set_bit(PG_arch_1, &page->flags);
84                 pg_addr += PAGE_SIZE;
85         }
86 }
87
88 inline void
89 ia64_set_rbs_bot (void)
90 {
91         unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16;
92
93         if (stack_size > MAX_USER_STACK_SIZE)
94                 stack_size = MAX_USER_STACK_SIZE;
95         current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
96 }
97
98 /*
99  * This performs some platform-dependent address space initialization.
100  * On IA-64, we want to setup the VM area for the register backing
101  * store (which grows upwards) and install the gateway page which is
102  * used for signal trampolines, etc.
103  */
104 void
105 ia64_init_addr_space (void)
106 {
107         struct vm_area_struct *vma;
108
109         ia64_set_rbs_bot();
110
111         /*
112          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
113          * the problem.  When the process attempts to write to the register backing store
114          * for the first time, it will get a SEGFAULT in this case.
115          */
116         vma = vm_area_alloc(current->mm);
117         if (vma) {
118                 vma_set_anonymous(vma);
119                 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
120                 vma->vm_end = vma->vm_start + PAGE_SIZE;
121                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
122                 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
123                 down_write(&current->mm->mmap_sem);
124                 if (insert_vm_struct(current->mm, vma)) {
125                         up_write(&current->mm->mmap_sem);
126                         vm_area_free(vma);
127                         return;
128                 }
129                 up_write(&current->mm->mmap_sem);
130         }
131
132         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
133         if (!(current->personality & MMAP_PAGE_ZERO)) {
134                 vma = vm_area_alloc(current->mm);
135                 if (vma) {
136                         vma_set_anonymous(vma);
137                         vma->vm_end = PAGE_SIZE;
138                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
139                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO |
140                                         VM_DONTEXPAND | VM_DONTDUMP;
141                         down_write(&current->mm->mmap_sem);
142                         if (insert_vm_struct(current->mm, vma)) {
143                                 up_write(&current->mm->mmap_sem);
144                                 vm_area_free(vma);
145                                 return;
146                         }
147                         up_write(&current->mm->mmap_sem);
148                 }
149         }
150 }
151
152 void
153 free_initmem (void)
154 {
155         free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end),
156                            -1, "unused kernel");
157 }
158
159 void __init
160 free_initrd_mem (unsigned long start, unsigned long end)
161 {
162         /*
163          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
164          * Thus EFI and the kernel may have different page sizes. It is
165          * therefore possible to have the initrd share the same page as
166          * the end of the kernel (given current setup).
167          *
168          * To avoid freeing/using the wrong page (kernel sized) we:
169          *      - align up the beginning of initrd
170          *      - align down the end of initrd
171          *
172          *  |             |
173          *  |=============| a000
174          *  |             |
175          *  |             |
176          *  |             | 9000
177          *  |/////////////|
178          *  |/////////////|
179          *  |=============| 8000
180          *  |///INITRD////|
181          *  |/////////////|
182          *  |/////////////| 7000
183          *  |             |
184          *  |KKKKKKKKKKKKK|
185          *  |=============| 6000
186          *  |KKKKKKKKKKKKK|
187          *  |KKKKKKKKKKKKK|
188          *  K=kernel using 8KB pages
189          *
190          * In this example, we must free page 8000 ONLY. So we must align up
191          * initrd_start and keep initrd_end as is.
192          */
193         start = PAGE_ALIGN(start);
194         end = end & PAGE_MASK;
195
196         if (start < end)
197                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
198
199         for (; start < end; start += PAGE_SIZE) {
200                 if (!virt_addr_valid(start))
201                         continue;
202                 free_reserved_page(virt_to_page(start));
203         }
204 }
205
206 /*
207  * This installs a clean page in the kernel's page table.
208  */
209 static struct page * __init
210 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
211 {
212         pgd_t *pgd;
213         pud_t *pud;
214         pmd_t *pmd;
215         pte_t *pte;
216
217         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
218
219         {
220                 pud = pud_alloc(&init_mm, pgd, address);
221                 if (!pud)
222                         goto out;
223                 pmd = pmd_alloc(&init_mm, pud, address);
224                 if (!pmd)
225                         goto out;
226                 pte = pte_alloc_kernel(pmd, address);
227                 if (!pte)
228                         goto out;
229                 if (!pte_none(*pte))
230                         goto out;
231                 set_pte(pte, mk_pte(page, pgprot));
232         }
233   out:
234         /* no need for flush_tlb */
235         return page;
236 }
237
238 static void __init
239 setup_gate (void)
240 {
241         struct page *page;
242
243         /*
244          * Map the gate page twice: once read-only to export the ELF
245          * headers etc. and once execute-only page to enable
246          * privilege-promotion via "epc":
247          */
248         page = virt_to_page(ia64_imva(__start_gate_section));
249         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
250 #ifdef HAVE_BUGGY_SEGREL
251         page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
252         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
253 #else
254         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
255         /* Fill in the holes (if any) with read-only zero pages: */
256         {
257                 unsigned long addr;
258
259                 for (addr = GATE_ADDR + PAGE_SIZE;
260                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
261                      addr += PAGE_SIZE)
262                 {
263                         put_kernel_page(ZERO_PAGE(0), addr,
264                                         PAGE_READONLY);
265                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
266                                         PAGE_READONLY);
267                 }
268         }
269 #endif
270         ia64_patch_gate();
271 }
272
273 static struct vm_area_struct gate_vma;
274
275 static int __init gate_vma_init(void)
276 {
277         vma_init(&gate_vma, NULL);
278         gate_vma.vm_start = FIXADDR_USER_START;
279         gate_vma.vm_end = FIXADDR_USER_END;
280         gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
281         gate_vma.vm_page_prot = __P101;
282
283         return 0;
284 }
285 __initcall(gate_vma_init);
286
287 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
288 {
289         return &gate_vma;
290 }
291
292 int in_gate_area_no_mm(unsigned long addr)
293 {
294         if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
295                 return 1;
296         return 0;
297 }
298
299 int in_gate_area(struct mm_struct *mm, unsigned long addr)
300 {
301         return in_gate_area_no_mm(addr);
302 }
303
304 void ia64_mmu_init(void *my_cpu_data)
305 {
306         unsigned long pta, impl_va_bits;
307         extern void tlb_init(void);
308
309 #ifdef CONFIG_DISABLE_VHPT
310 #       define VHPT_ENABLE_BIT  0
311 #else
312 #       define VHPT_ENABLE_BIT  1
313 #endif
314
315         /*
316          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
317          * address space.  The IA-64 architecture guarantees that at least 50 bits of
318          * virtual address space are implemented but if we pick a large enough page size
319          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
320          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
321          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
322          * problem in practice.  Alternatively, we could truncate the top of the mapped
323          * address space to not permit mappings that would overlap with the VMLPT.
324          * --davidm 00/12/06
325          */
326 #       define pte_bits                 3
327 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
328         /*
329          * The virtual page table has to cover the entire implemented address space within
330          * a region even though not all of this space may be mappable.  The reason for
331          * this is that the Access bit and Dirty bit fault handlers perform
332          * non-speculative accesses to the virtual page table, so the address range of the
333          * virtual page table itself needs to be covered by virtual page table.
334          */
335 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
336 #       define POW2(n)                  (1ULL << (n))
337
338         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
339
340         if (impl_va_bits < 51 || impl_va_bits > 61)
341                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
342         /*
343          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
344          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
345          * the test makes sure that our mapped space doesn't overlap the
346          * unimplemented hole in the middle of the region.
347          */
348         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
349             (mapped_space_bits > impl_va_bits - 1))
350                 panic("Cannot build a big enough virtual-linear page table"
351                       " to cover mapped address space.\n"
352                       " Try using a smaller page size.\n");
353
354
355         /* place the VMLPT at the end of each page-table mapped region: */
356         pta = POW2(61) - POW2(vmlpt_bits);
357
358         /*
359          * Set the (virtually mapped linear) page table address.  Bit
360          * 8 selects between the short and long format, bits 2-7 the
361          * size of the table, and bit 0 whether the VHPT walker is
362          * enabled.
363          */
364         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
365
366         ia64_tlb_init();
367
368 #ifdef  CONFIG_HUGETLB_PAGE
369         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
370         ia64_srlz_d();
371 #endif
372 }
373
374 #ifdef CONFIG_VIRTUAL_MEM_MAP
375 int vmemmap_find_next_valid_pfn(int node, int i)
376 {
377         unsigned long end_address, hole_next_pfn;
378         unsigned long stop_address;
379         pg_data_t *pgdat = NODE_DATA(node);
380
381         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
382         end_address = PAGE_ALIGN(end_address);
383         stop_address = (unsigned long) &vmem_map[pgdat_end_pfn(pgdat)];
384
385         do {
386                 pgd_t *pgd;
387                 pud_t *pud;
388                 pmd_t *pmd;
389                 pte_t *pte;
390
391                 pgd = pgd_offset_k(end_address);
392                 if (pgd_none(*pgd)) {
393                         end_address += PGDIR_SIZE;
394                         continue;
395                 }
396
397                 pud = pud_offset(pgd, end_address);
398                 if (pud_none(*pud)) {
399                         end_address += PUD_SIZE;
400                         continue;
401                 }
402
403                 pmd = pmd_offset(pud, end_address);
404                 if (pmd_none(*pmd)) {
405                         end_address += PMD_SIZE;
406                         continue;
407                 }
408
409                 pte = pte_offset_kernel(pmd, end_address);
410 retry_pte:
411                 if (pte_none(*pte)) {
412                         end_address += PAGE_SIZE;
413                         pte++;
414                         if ((end_address < stop_address) &&
415                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
416                                 goto retry_pte;
417                         continue;
418                 }
419                 /* Found next valid vmem_map page */
420                 break;
421         } while (end_address < stop_address);
422
423         end_address = min(end_address, stop_address);
424         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
425         hole_next_pfn = end_address / sizeof(struct page);
426         return hole_next_pfn - pgdat->node_start_pfn;
427 }
428
429 int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
430 {
431         unsigned long address, start_page, end_page;
432         struct page *map_start, *map_end;
433         int node;
434         pgd_t *pgd;
435         pud_t *pud;
436         pmd_t *pmd;
437         pte_t *pte;
438
439         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
440         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
441
442         start_page = (unsigned long) map_start & PAGE_MASK;
443         end_page = PAGE_ALIGN((unsigned long) map_end);
444         node = paddr_to_nid(__pa(start));
445
446         for (address = start_page; address < end_page; address += PAGE_SIZE) {
447                 pgd = pgd_offset_k(address);
448                 if (pgd_none(*pgd))
449                         pgd_populate(&init_mm, pgd, memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node));
450                 pud = pud_offset(pgd, address);
451
452                 if (pud_none(*pud))
453                         pud_populate(&init_mm, pud, memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node));
454                 pmd = pmd_offset(pud, address);
455
456                 if (pmd_none(*pmd))
457                         pmd_populate_kernel(&init_mm, pmd, memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node));
458                 pte = pte_offset_kernel(pmd, address);
459
460                 if (pte_none(*pte))
461                         set_pte(pte, pfn_pte(__pa(memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node)) >> PAGE_SHIFT,
462                                              PAGE_KERNEL));
463         }
464         return 0;
465 }
466
467 struct memmap_init_callback_data {
468         struct page *start;
469         struct page *end;
470         int nid;
471         unsigned long zone;
472 };
473
474 static int __meminit
475 virtual_memmap_init(u64 start, u64 end, void *arg)
476 {
477         struct memmap_init_callback_data *args;
478         struct page *map_start, *map_end;
479
480         args = (struct memmap_init_callback_data *) arg;
481         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
482         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
483
484         if (map_start < args->start)
485                 map_start = args->start;
486         if (map_end > args->end)
487                 map_end = args->end;
488
489         /*
490          * We have to initialize "out of bounds" struct page elements that fit completely
491          * on the same pages that were allocated for the "in bounds" elements because they
492          * may be referenced later (and found to be "reserved").
493          */
494         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
495         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
496                     / sizeof(struct page));
497
498         if (map_start < map_end)
499                 memmap_init_zone((unsigned long)(map_end - map_start),
500                                  args->nid, args->zone, page_to_pfn(map_start),
501                                  MEMMAP_EARLY, NULL);
502         return 0;
503 }
504
505 void __meminit
506 memmap_init (unsigned long size, int nid, unsigned long zone,
507              unsigned long start_pfn)
508 {
509         if (!vmem_map) {
510                 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY,
511                                 NULL);
512         } else {
513                 struct page *start;
514                 struct memmap_init_callback_data args;
515
516                 start = pfn_to_page(start_pfn);
517                 args.start = start;
518                 args.end = start + size;
519                 args.nid = nid;
520                 args.zone = zone;
521
522                 efi_memmap_walk(virtual_memmap_init, &args);
523         }
524 }
525
526 int
527 ia64_pfn_valid (unsigned long pfn)
528 {
529         char byte;
530         struct page *pg = pfn_to_page(pfn);
531
532         return     (__get_user(byte, (char __user *) pg) == 0)
533                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
534                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
535 }
536 EXPORT_SYMBOL(ia64_pfn_valid);
537
538 int __init find_largest_hole(u64 start, u64 end, void *arg)
539 {
540         u64 *max_gap = arg;
541
542         static u64 last_end = PAGE_OFFSET;
543
544         /* NOTE: this algorithm assumes efi memmap table is ordered */
545
546         if (*max_gap < (start - last_end))
547                 *max_gap = start - last_end;
548         last_end = end;
549         return 0;
550 }
551
552 #endif /* CONFIG_VIRTUAL_MEM_MAP */
553
554 int __init register_active_ranges(u64 start, u64 len, int nid)
555 {
556         u64 end = start + len;
557
558 #ifdef CONFIG_KEXEC
559         if (start > crashk_res.start && start < crashk_res.end)
560                 start = crashk_res.end;
561         if (end > crashk_res.start && end < crashk_res.end)
562                 end = crashk_res.start;
563 #endif
564
565         if (start < end)
566                 memblock_add_node(__pa(start), end - start, nid);
567         return 0;
568 }
569
570 int
571 find_max_min_low_pfn (u64 start, u64 end, void *arg)
572 {
573         unsigned long pfn_start, pfn_end;
574 #ifdef CONFIG_FLATMEM
575         pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
576         pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
577 #else
578         pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
579         pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
580 #endif
581         min_low_pfn = min(min_low_pfn, pfn_start);
582         max_low_pfn = max(max_low_pfn, pfn_end);
583         return 0;
584 }
585
586 /*
587  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
588  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
589  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
590  * useful for performance testing, but conceivably could also come in handy for debugging
591  * purposes.
592  */
593
594 static int nolwsys __initdata;
595
596 static int __init
597 nolwsys_setup (char *s)
598 {
599         nolwsys = 1;
600         return 1;
601 }
602
603 __setup("nolwsys", nolwsys_setup);
604
605 void __init
606 mem_init (void)
607 {
608         int i;
609
610         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
611         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
612         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
613
614 #ifdef CONFIG_PCI
615         /*
616          * This needs to be called _after_ the command line has been parsed but _before_
617          * any drivers that may need the PCI DMA interface are initialized or bootmem has
618          * been freed.
619          */
620         platform_dma_init();
621 #endif
622
623 #ifdef CONFIG_FLATMEM
624         BUG_ON(!mem_map);
625 #endif
626
627         set_max_mapnr(max_low_pfn);
628         high_memory = __va(max_low_pfn * PAGE_SIZE);
629         memblock_free_all();
630         mem_init_print_info(NULL);
631
632         /*
633          * For fsyscall entrpoints with no light-weight handler, use the ordinary
634          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
635          * code can tell them apart.
636          */
637         for (i = 0; i < NR_syscalls; ++i) {
638                 extern unsigned long fsyscall_table[NR_syscalls];
639                 extern unsigned long sys_call_table[NR_syscalls];
640
641                 if (!fsyscall_table[i] || nolwsys)
642                         fsyscall_table[i] = sys_call_table[i] | 1;
643         }
644         setup_gate();
645 }
646
647 #ifdef CONFIG_MEMORY_HOTPLUG
648 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
649                 bool want_memblock)
650 {
651         unsigned long start_pfn = start >> PAGE_SHIFT;
652         unsigned long nr_pages = size >> PAGE_SHIFT;
653         int ret;
654
655         ret = __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
656         if (ret)
657                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
658                        __func__,  ret);
659
660         return ret;
661 }
662
663 #ifdef CONFIG_MEMORY_HOTREMOVE
664 int arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap)
665 {
666         unsigned long start_pfn = start >> PAGE_SHIFT;
667         unsigned long nr_pages = size >> PAGE_SHIFT;
668         struct zone *zone;
669         int ret;
670
671         zone = page_zone(pfn_to_page(start_pfn));
672         ret = __remove_pages(zone, start_pfn, nr_pages, altmap);
673         if (ret)
674                 pr_warn("%s: Problem encountered in __remove_pages() as"
675                         " ret=%d\n", __func__,  ret);
676
677         return ret;
678 }
679 #endif
680 #endif