powerpc/mm/altmap: Fix altmap boundary check

[ Upstream commit 6722b25712 ]

altmap->free includes the entire free space from which altmap blocks
can be allocated. So when checking whether the kernel is doing altmap
block free, compute the boundary correctly, otherwise memory hotunplug
can fail.

Fixes: 9ef34630a4 ("powerpc/mm: Fallback to RAM if the altmap is unusable")
Signed-off-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230724181320.471386-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Aneesh Kumar K.V 2023-07-24 23:43:20 +05:30 committed by Greg Kroah-Hartman
parent 49e57caf96
commit bbfa34c97d

View file

@ -314,8 +314,7 @@ void __ref vmemmap_free(unsigned long start, unsigned long end,
start = ALIGN_DOWN(start, page_size);
if (altmap) {
alt_start = altmap->base_pfn;
alt_end = altmap->base_pfn + altmap->reserve +
altmap->free + altmap->alloc + altmap->align;
alt_end = altmap->base_pfn + altmap->reserve + altmap->free;
}
pr_debug("vmemmap_free %lx...%lx\n", start, end);