Hotplugged memory can be smaller than the original memory. For example,
on my target:
root@genericarmv8:~# cat /sys/kernel/debug/memblock/memory
0: 0x0000000064005000..0x0000000064023fff 0 NOMAP
1: 0x0000000064400000..0x00000000647fffff 0 NOMAP
2: 0x0000000068000000..0x000000006fffffff 0 DRV_MNG
3: 0x0000000088800000..0x0000000094ffefff 0 NONE
4: 0x0000000094fff000..0x0000000094ffffff 0 NOMAP
max_pfn will affect read_page_owner. Therefore, it should first compare and
then select the larger value for max_pfn.
Fixes: 8fac67ca236b ("arm64: mm: update max_pfn after memory hotplug")
Signed-off-by: Zhenhua Huang <quic_zhenhuah@xxxxxxxxxxx>
---
arch/arm64/mm/mmu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 1dfe1a8efdbe..310ff75891ef 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1361,7 +1361,8 @@ int arch_add_memory(int nid, u64 start, u64 size,
__remove_pgd_mapping(swapper_pg_dir,
__phys_to_virt(start), size);
else {
- max_pfn = PFN_UP(start + size);
+ /* Address of hotplugged memory can be smaller */
+ max_pfn = max(max_pfn, PFN_UP(start + size));
max_low_pfn = max_pfn;
}
--
2.25.1
