1 // SPDX-License-Identifier: GPL-2.0
3 * sparse memory mappings.
6 #include <linux/slab.h>
7 #include <linux/mmzone.h>
8 #include <linux/memblock.h>
9 #include <linux/compiler.h>
10 #include <linux/highmem.h>
11 #include <linux/export.h>
12 #include <linux/spinlock.h>
13 #include <linux/vmalloc.h>
17 #include <asm/pgalloc.h>
18 #include <asm/pgtable.h>
21 * Permanent SPARSEMEM data:
23 * 1) mem_section - memory sections, mem_map's for valid memory
25 #ifdef CONFIG_SPARSEMEM_EXTREME
26 struct mem_section
**mem_section
;
28 struct mem_section mem_section
[NR_SECTION_ROOTS
][SECTIONS_PER_ROOT
]
29 ____cacheline_internodealigned_in_smp
;
31 EXPORT_SYMBOL(mem_section
);
33 #ifdef NODE_NOT_IN_PAGE_FLAGS
35 * If we did not store the node number in the page then we have to
36 * do a lookup in the section_to_node_table in order to find which
37 * node the page belongs to.
39 #if MAX_NUMNODES <= 256
40 static u8 section_to_node_table
[NR_MEM_SECTIONS
] __cacheline_aligned
;
42 static u16 section_to_node_table
[NR_MEM_SECTIONS
] __cacheline_aligned
;
45 int page_to_nid(const struct page
*page
)
47 return section_to_node_table
[page_to_section(page
)];
49 EXPORT_SYMBOL(page_to_nid
);
51 static void set_section_nid(unsigned long section_nr
, int nid
)
53 section_to_node_table
[section_nr
] = nid
;
55 #else /* !NODE_NOT_IN_PAGE_FLAGS */
56 static inline void set_section_nid(unsigned long section_nr
, int nid
)
61 #ifdef CONFIG_SPARSEMEM_EXTREME
62 static noinline
struct mem_section __ref
*sparse_index_alloc(int nid
)
64 struct mem_section
*section
= NULL
;
65 unsigned long array_size
= SECTIONS_PER_ROOT
*
66 sizeof(struct mem_section
);
68 if (slab_is_available())
69 section
= kzalloc_node(array_size
, GFP_KERNEL
, nid
);
71 section
= memblock_alloc_node(array_size
, SMP_CACHE_BYTES
,
77 static int __meminit
sparse_index_init(unsigned long section_nr
, int nid
)
79 unsigned long root
= SECTION_NR_TO_ROOT(section_nr
);
80 struct mem_section
*section
;
82 if (mem_section
[root
])
85 section
= sparse_index_alloc(nid
);
89 mem_section
[root
] = section
;
93 #else /* !SPARSEMEM_EXTREME */
94 static inline int sparse_index_init(unsigned long section_nr
, int nid
)
100 #ifdef CONFIG_SPARSEMEM_EXTREME
101 int __section_nr(struct mem_section
* ms
)
103 unsigned long root_nr
;
104 struct mem_section
*root
= NULL
;
106 for (root_nr
= 0; root_nr
< NR_SECTION_ROOTS
; root_nr
++) {
107 root
= __nr_to_section(root_nr
* SECTIONS_PER_ROOT
);
111 if ((ms
>= root
) && (ms
< (root
+ SECTIONS_PER_ROOT
)))
117 return (root_nr
* SECTIONS_PER_ROOT
) + (ms
- root
);
120 int __section_nr(struct mem_section
* ms
)
122 return (int)(ms
- mem_section
[0]);
127 * During early boot, before section_mem_map is used for an actual
128 * mem_map, we use section_mem_map to store the section's NUMA
129 * node. This keeps us from having to use another data structure. The
130 * node information is cleared just before we store the real mem_map.
132 static inline unsigned long sparse_encode_early_nid(int nid
)
134 return (nid
<< SECTION_NID_SHIFT
);
137 static inline int sparse_early_nid(struct mem_section
*section
)
139 return (section
->section_mem_map
>> SECTION_NID_SHIFT
);
142 /* Validate the physical addressing limitations of the model */
143 void __meminit
mminit_validate_memmodel_limits(unsigned long *start_pfn
,
144 unsigned long *end_pfn
)
146 unsigned long max_sparsemem_pfn
= 1UL << (MAX_PHYSMEM_BITS
-PAGE_SHIFT
);
149 * Sanity checks - do not allow an architecture to pass
150 * in larger pfns than the maximum scope of sparsemem:
152 if (*start_pfn
> max_sparsemem_pfn
) {
153 mminit_dprintk(MMINIT_WARNING
, "pfnvalidation",
154 "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
155 *start_pfn
, *end_pfn
, max_sparsemem_pfn
);
157 *start_pfn
= max_sparsemem_pfn
;
158 *end_pfn
= max_sparsemem_pfn
;
159 } else if (*end_pfn
> max_sparsemem_pfn
) {
160 mminit_dprintk(MMINIT_WARNING
, "pfnvalidation",
161 "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
162 *start_pfn
, *end_pfn
, max_sparsemem_pfn
);
164 *end_pfn
= max_sparsemem_pfn
;
169 * There are a number of times that we loop over NR_MEM_SECTIONS,
170 * looking for section_present() on each. But, when we have very
171 * large physical address spaces, NR_MEM_SECTIONS can also be
172 * very large which makes the loops quite long.
174 * Keeping track of this gives us an easy way to break out of
177 int __highest_present_section_nr
;
178 static void section_mark_present(struct mem_section
*ms
)
180 int section_nr
= __section_nr(ms
);
182 if (section_nr
> __highest_present_section_nr
)
183 __highest_present_section_nr
= section_nr
;
185 ms
->section_mem_map
|= SECTION_MARKED_PRESENT
;
188 static inline int next_present_section_nr(int section_nr
)
192 if (present_section_nr(section_nr
))
194 } while ((section_nr
<= __highest_present_section_nr
));
198 #define for_each_present_section_nr(start, section_nr) \
199 for (section_nr = next_present_section_nr(start-1); \
200 ((section_nr >= 0) && \
201 (section_nr <= __highest_present_section_nr)); \
202 section_nr = next_present_section_nr(section_nr))
204 static inline unsigned long first_present_section_nr(void)
206 return next_present_section_nr(-1);
209 /* Record a memory area against a node. */
210 void __init
memory_present(int nid
, unsigned long start
, unsigned long end
)
214 #ifdef CONFIG_SPARSEMEM_EXTREME
215 if (unlikely(!mem_section
)) {
216 unsigned long size
, align
;
218 size
= sizeof(struct mem_section
*) * NR_SECTION_ROOTS
;
219 align
= 1 << (INTERNODE_CACHE_SHIFT
);
220 mem_section
= memblock_alloc(size
, align
);
224 start
&= PAGE_SECTION_MASK
;
225 mminit_validate_memmodel_limits(&start
, &end
);
226 for (pfn
= start
; pfn
< end
; pfn
+= PAGES_PER_SECTION
) {
227 unsigned long section
= pfn_to_section_nr(pfn
);
228 struct mem_section
*ms
;
230 sparse_index_init(section
, nid
);
231 set_section_nid(section
, nid
);
233 ms
= __nr_to_section(section
);
234 if (!ms
->section_mem_map
) {
235 ms
->section_mem_map
= sparse_encode_early_nid(nid
) |
237 section_mark_present(ms
);
243 * Subtle, we encode the real pfn into the mem_map such that
244 * the identity pfn - section_mem_map will return the actual
245 * physical page frame number.
247 static unsigned long sparse_encode_mem_map(struct page
*mem_map
, unsigned long pnum
)
249 unsigned long coded_mem_map
=
250 (unsigned long)(mem_map
- (section_nr_to_pfn(pnum
)));
251 BUILD_BUG_ON(SECTION_MAP_LAST_BIT
> (1UL<<PFN_SECTION_SHIFT
));
252 BUG_ON(coded_mem_map
& ~SECTION_MAP_MASK
);
253 return coded_mem_map
;
257 * Decode mem_map from the coded memmap
259 struct page
*sparse_decode_mem_map(unsigned long coded_mem_map
, unsigned long pnum
)
261 /* mask off the extra low bits of information */
262 coded_mem_map
&= SECTION_MAP_MASK
;
263 return ((struct page
*)coded_mem_map
) + section_nr_to_pfn(pnum
);
266 static void __meminit
sparse_init_one_section(struct mem_section
*ms
,
267 unsigned long pnum
, struct page
*mem_map
,
268 unsigned long *pageblock_bitmap
)
270 ms
->section_mem_map
&= ~SECTION_MAP_MASK
;
271 ms
->section_mem_map
|= sparse_encode_mem_map(mem_map
, pnum
) |
273 ms
->pageblock_flags
= pageblock_bitmap
;
276 unsigned long usemap_size(void)
278 return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS
) * sizeof(unsigned long);
281 #ifdef CONFIG_MEMORY_HOTPLUG
282 static unsigned long *__kmalloc_section_usemap(void)
284 return kmalloc(usemap_size(), GFP_KERNEL
);
286 #endif /* CONFIG_MEMORY_HOTPLUG */
288 #ifdef CONFIG_MEMORY_HOTREMOVE
289 static unsigned long * __init
290 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data
*pgdat
,
293 unsigned long goal
, limit
;
297 * A page may contain usemaps for other sections preventing the
298 * page being freed and making a section unremovable while
299 * other sections referencing the usemap remain active. Similarly,
300 * a pgdat can prevent a section being removed. If section A
301 * contains a pgdat and section B contains the usemap, both
302 * sections become inter-dependent. This allocates usemaps
303 * from the same section as the pgdat where possible to avoid
306 goal
= __pa(pgdat
) & (PAGE_SECTION_MASK
<< PAGE_SHIFT
);
307 limit
= goal
+ (1UL << PA_SECTION_SHIFT
);
308 nid
= early_pfn_to_nid(goal
>> PAGE_SHIFT
);
310 p
= memblock_alloc_try_nid_nopanic(size
,
311 SMP_CACHE_BYTES
, goal
, limit
,
320 static void __init
check_usemap_section_nr(int nid
, unsigned long *usemap
)
322 unsigned long usemap_snr
, pgdat_snr
;
323 static unsigned long old_usemap_snr
;
324 static unsigned long old_pgdat_snr
;
325 struct pglist_data
*pgdat
= NODE_DATA(nid
);
329 if (!old_usemap_snr
) {
330 old_usemap_snr
= NR_MEM_SECTIONS
;
331 old_pgdat_snr
= NR_MEM_SECTIONS
;
334 usemap_snr
= pfn_to_section_nr(__pa(usemap
) >> PAGE_SHIFT
);
335 pgdat_snr
= pfn_to_section_nr(__pa(pgdat
) >> PAGE_SHIFT
);
336 if (usemap_snr
== pgdat_snr
)
339 if (old_usemap_snr
== usemap_snr
&& old_pgdat_snr
== pgdat_snr
)
340 /* skip redundant message */
343 old_usemap_snr
= usemap_snr
;
344 old_pgdat_snr
= pgdat_snr
;
346 usemap_nid
= sparse_early_nid(__nr_to_section(usemap_snr
));
347 if (usemap_nid
!= nid
) {
348 pr_info("node %d must be removed before remove section %ld\n",
353 * There is a circular dependency.
354 * Some platforms allow un-removable section because they will just
355 * gather other removable sections for dynamic partitioning.
356 * Just notify un-removable section's number here.
358 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
359 usemap_snr
, pgdat_snr
, nid
);
362 static unsigned long * __init
363 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data
*pgdat
,
366 return memblock_alloc_node_nopanic(size
, pgdat
->node_id
);
369 static void __init
check_usemap_section_nr(int nid
, unsigned long *usemap
)
372 #endif /* CONFIG_MEMORY_HOTREMOVE */
374 #ifdef CONFIG_SPARSEMEM_VMEMMAP
375 static unsigned long __init
section_map_size(void)
377 return ALIGN(sizeof(struct page
) * PAGES_PER_SECTION
, PMD_SIZE
);
381 static unsigned long __init
section_map_size(void)
383 return PAGE_ALIGN(sizeof(struct page
) * PAGES_PER_SECTION
);
386 struct page __init
*sparse_mem_map_populate(unsigned long pnum
, int nid
,
387 struct vmem_altmap
*altmap
)
389 unsigned long size
= section_map_size();
390 struct page
*map
= sparse_buffer_alloc(size
);
395 map
= memblock_alloc_try_nid(size
,
396 PAGE_SIZE
, __pa(MAX_DMA_ADDRESS
),
397 MEMBLOCK_ALLOC_ACCESSIBLE
, nid
);
400 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
402 static void *sparsemap_buf __meminitdata
;
403 static void *sparsemap_buf_end __meminitdata
;
405 static void __init
sparse_buffer_init(unsigned long size
, int nid
)
407 WARN_ON(sparsemap_buf
); /* forgot to call sparse_buffer_fini()? */
409 memblock_alloc_try_nid_raw(size
, PAGE_SIZE
,
410 __pa(MAX_DMA_ADDRESS
),
411 MEMBLOCK_ALLOC_ACCESSIBLE
, nid
);
412 sparsemap_buf_end
= sparsemap_buf
+ size
;
415 static void __init
sparse_buffer_fini(void)
417 unsigned long size
= sparsemap_buf_end
- sparsemap_buf
;
419 if (sparsemap_buf
&& size
> 0)
420 memblock_free_early(__pa(sparsemap_buf
), size
);
421 sparsemap_buf
= NULL
;
424 void * __meminit
sparse_buffer_alloc(unsigned long size
)
429 ptr
= PTR_ALIGN(sparsemap_buf
, size
);
430 if (ptr
+ size
> sparsemap_buf_end
)
433 sparsemap_buf
= ptr
+ size
;
438 void __weak __meminit
vmemmap_populate_print_last(void)
443 * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end)
444 * And number of present sections in this node is map_count.
446 static void __init
sparse_init_nid(int nid
, unsigned long pnum_begin
,
447 unsigned long pnum_end
,
448 unsigned long map_count
)
450 unsigned long pnum
, usemap_longs
, *usemap
;
453 usemap_longs
= BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS
);
454 usemap
= sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid
),
458 pr_err("%s: node[%d] usemap allocation failed", __func__
, nid
);
461 sparse_buffer_init(map_count
* section_map_size(), nid
);
462 for_each_present_section_nr(pnum_begin
, pnum
) {
463 if (pnum
>= pnum_end
)
466 map
= sparse_mem_map_populate(pnum
, nid
, NULL
);
468 pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
473 check_usemap_section_nr(nid
, usemap
);
474 sparse_init_one_section(__nr_to_section(pnum
), pnum
, map
, usemap
);
475 usemap
+= usemap_longs
;
477 sparse_buffer_fini();
480 /* We failed to allocate, mark all the following pnums as not present */
481 for_each_present_section_nr(pnum_begin
, pnum
) {
482 struct mem_section
*ms
;
484 if (pnum
>= pnum_end
)
486 ms
= __nr_to_section(pnum
);
487 ms
->section_mem_map
= 0;
492 * Allocate the accumulated non-linear sections, allocate a mem_map
493 * for each and record the physical to section mapping.
495 void __init
sparse_init(void)
497 unsigned long pnum_begin
= first_present_section_nr();
498 int nid_begin
= sparse_early_nid(__nr_to_section(pnum_begin
));
499 unsigned long pnum_end
, map_count
= 1;
501 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
502 set_pageblock_order();
504 for_each_present_section_nr(pnum_begin
+ 1, pnum_end
) {
505 int nid
= sparse_early_nid(__nr_to_section(pnum_end
));
507 if (nid
== nid_begin
) {
511 /* Init node with sections in range [pnum_begin, pnum_end) */
512 sparse_init_nid(nid_begin
, pnum_begin
, pnum_end
, map_count
);
514 pnum_begin
= pnum_end
;
517 /* cover the last node */
518 sparse_init_nid(nid_begin
, pnum_begin
, pnum_end
, map_count
);
519 vmemmap_populate_print_last();
522 #ifdef CONFIG_MEMORY_HOTPLUG
524 /* Mark all memory sections within the pfn range as online */
525 void online_mem_sections(unsigned long start_pfn
, unsigned long end_pfn
)
529 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
530 unsigned long section_nr
= pfn_to_section_nr(pfn
);
531 struct mem_section
*ms
;
533 /* onlining code should never touch invalid ranges */
534 if (WARN_ON(!valid_section_nr(section_nr
)))
537 ms
= __nr_to_section(section_nr
);
538 ms
->section_mem_map
|= SECTION_IS_ONLINE
;
542 #ifdef CONFIG_MEMORY_HOTREMOVE
543 /* Mark all memory sections within the pfn range as online */
544 void offline_mem_sections(unsigned long start_pfn
, unsigned long end_pfn
)
548 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= PAGES_PER_SECTION
) {
549 unsigned long section_nr
= pfn_to_section_nr(pfn
);
550 struct mem_section
*ms
;
553 * TODO this needs some double checking. Offlining code makes
554 * sure to check pfn_valid but those checks might be just bogus
556 if (WARN_ON(!valid_section_nr(section_nr
)))
559 ms
= __nr_to_section(section_nr
);
560 ms
->section_mem_map
&= ~SECTION_IS_ONLINE
;
565 #ifdef CONFIG_SPARSEMEM_VMEMMAP
566 static inline struct page
*kmalloc_section_memmap(unsigned long pnum
, int nid
,
567 struct vmem_altmap
*altmap
)
569 /* This will make the necessary allocations eventually. */
570 return sparse_mem_map_populate(pnum
, nid
, altmap
);
572 static void __kfree_section_memmap(struct page
*memmap
,
573 struct vmem_altmap
*altmap
)
575 unsigned long start
= (unsigned long)memmap
;
576 unsigned long end
= (unsigned long)(memmap
+ PAGES_PER_SECTION
);
578 vmemmap_free(start
, end
, altmap
);
580 #ifdef CONFIG_MEMORY_HOTREMOVE
581 static void free_map_bootmem(struct page
*memmap
)
583 unsigned long start
= (unsigned long)memmap
;
584 unsigned long end
= (unsigned long)(memmap
+ PAGES_PER_SECTION
);
586 vmemmap_free(start
, end
, NULL
);
588 #endif /* CONFIG_MEMORY_HOTREMOVE */
590 static struct page
*__kmalloc_section_memmap(void)
592 struct page
*page
, *ret
;
593 unsigned long memmap_size
= sizeof(struct page
) * PAGES_PER_SECTION
;
595 page
= alloc_pages(GFP_KERNEL
|__GFP_NOWARN
, get_order(memmap_size
));
599 ret
= vmalloc(memmap_size
);
605 ret
= (struct page
*)pfn_to_kaddr(page_to_pfn(page
));
611 static inline struct page
*kmalloc_section_memmap(unsigned long pnum
, int nid
,
612 struct vmem_altmap
*altmap
)
614 return __kmalloc_section_memmap();
617 static void __kfree_section_memmap(struct page
*memmap
,
618 struct vmem_altmap
*altmap
)
620 if (is_vmalloc_addr(memmap
))
623 free_pages((unsigned long)memmap
,
624 get_order(sizeof(struct page
) * PAGES_PER_SECTION
));
627 #ifdef CONFIG_MEMORY_HOTREMOVE
628 static void free_map_bootmem(struct page
*memmap
)
630 unsigned long maps_section_nr
, removing_section_nr
, i
;
631 unsigned long magic
, nr_pages
;
632 struct page
*page
= virt_to_page(memmap
);
634 nr_pages
= PAGE_ALIGN(PAGES_PER_SECTION
* sizeof(struct page
))
637 for (i
= 0; i
< nr_pages
; i
++, page
++) {
638 magic
= (unsigned long) page
->freelist
;
640 BUG_ON(magic
== NODE_INFO
);
642 maps_section_nr
= pfn_to_section_nr(page_to_pfn(page
));
643 removing_section_nr
= page_private(page
);
646 * When this function is called, the removing section is
647 * logical offlined state. This means all pages are isolated
648 * from page allocator. If removing section's memmap is placed
649 * on the same section, it must not be freed.
650 * If it is freed, page allocator may allocate it which will
651 * be removed physically soon.
653 if (maps_section_nr
!= removing_section_nr
)
654 put_page_bootmem(page
);
657 #endif /* CONFIG_MEMORY_HOTREMOVE */
658 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
661 * returns the number of sections whose mem_maps were properly
662 * set. If this is <=0, then that means that the passed-in
663 * map was not consumed and must be freed.
665 int __meminit
sparse_add_one_section(struct pglist_data
*pgdat
,
666 unsigned long start_pfn
, struct vmem_altmap
*altmap
)
668 unsigned long section_nr
= pfn_to_section_nr(start_pfn
);
669 struct mem_section
*ms
;
671 unsigned long *usemap
;
676 * no locking for this, because it does its own
677 * plus, it does a kmalloc
679 ret
= sparse_index_init(section_nr
, pgdat
->node_id
);
680 if (ret
< 0 && ret
!= -EEXIST
)
683 memmap
= kmalloc_section_memmap(section_nr
, pgdat
->node_id
, altmap
);
686 usemap
= __kmalloc_section_usemap();
688 __kfree_section_memmap(memmap
, altmap
);
692 pgdat_resize_lock(pgdat
, &flags
);
694 ms
= __pfn_to_section(start_pfn
);
695 if (ms
->section_mem_map
& SECTION_MARKED_PRESENT
) {
701 * Poison uninitialized struct pages in order to catch invalid flags
704 page_init_poison(memmap
, sizeof(struct page
) * PAGES_PER_SECTION
);
706 section_mark_present(ms
);
707 sparse_init_one_section(ms
, section_nr
, memmap
, usemap
);
710 pgdat_resize_unlock(pgdat
, &flags
);
713 __kfree_section_memmap(memmap
, altmap
);
718 #ifdef CONFIG_MEMORY_HOTREMOVE
719 #ifdef CONFIG_MEMORY_FAILURE
720 static void clear_hwpoisoned_pages(struct page
*memmap
, int nr_pages
)
727 for (i
= 0; i
< nr_pages
; i
++) {
728 if (PageHWPoison(&memmap
[i
])) {
729 atomic_long_sub(1, &num_poisoned_pages
);
730 ClearPageHWPoison(&memmap
[i
]);
735 static inline void clear_hwpoisoned_pages(struct page
*memmap
, int nr_pages
)
740 static void free_section_usemap(struct page
*memmap
, unsigned long *usemap
,
741 struct vmem_altmap
*altmap
)
743 struct page
*usemap_page
;
748 usemap_page
= virt_to_page(usemap
);
750 * Check to see if allocation came from hot-plug-add
752 if (PageSlab(usemap_page
) || PageCompound(usemap_page
)) {
755 __kfree_section_memmap(memmap
, altmap
);
760 * The usemap came from bootmem. This is packed with other usemaps
761 * on the section which has pgdat at boot time. Just keep it as is now.
765 free_map_bootmem(memmap
);
768 void sparse_remove_one_section(struct zone
*zone
, struct mem_section
*ms
,
769 unsigned long map_offset
, struct vmem_altmap
*altmap
)
771 struct page
*memmap
= NULL
;
772 unsigned long *usemap
= NULL
, flags
;
773 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
775 pgdat_resize_lock(pgdat
, &flags
);
776 if (ms
->section_mem_map
) {
777 usemap
= ms
->pageblock_flags
;
778 memmap
= sparse_decode_mem_map(ms
->section_mem_map
,
780 ms
->section_mem_map
= 0;
781 ms
->pageblock_flags
= NULL
;
783 pgdat_resize_unlock(pgdat
, &flags
);
785 clear_hwpoisoned_pages(memmap
+ map_offset
,
786 PAGES_PER_SECTION
- map_offset
);
787 free_section_usemap(memmap
, usemap
, altmap
);
789 #endif /* CONFIG_MEMORY_HOTREMOVE */
790 #endif /* CONFIG_MEMORY_HOTPLUG */