Re: [RFC] arm64: mm: update max_pfn after memory hotplug

From: David Hildenbrand
Date: Mon Sep 27 2021 - 11:51:48 EST


On 24.09.21 00:54, Chris Goldsworthy wrote:
From: Sudarshan Rajagopalan <quic_sudaraja@xxxxxxxxxxx>

After new memory blocks have been hotplugged, max_pfn and max_low_pfn
needs updating to reflect on new PFNs being hot added to system.

Signed-off-by: Sudarshan Rajagopalan <quic_sudaraja@xxxxxxxxxxx>
Signed-off-by: Chris Goldsworthy <quic_cgoldswo@xxxxxxxxxxx>
---
arch/arm64/mm/mmu.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index cfd9deb..fd85b51 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1499,6 +1499,11 @@ int arch_add_memory(int nid, u64 start, u64 size,
if (ret)
__remove_pgd_mapping(swapper_pg_dir,
__phys_to_virt(start), size);
+ else {
+ max_pfn = PFN_UP(start + size);
+ max_low_pfn = max_pfn;
+ }
+
return ret;

Note: didn't verify if updating max_low_pfn is correct here.

Acked-by: David Hildenbrand <david@xxxxxxxxxx>


--
Thanks,

David / dhildenb