Re: [PATCH 5.15 2/2] arm64/mm: drop HAVE_ARCH_PFN_VALID

On Wed, Apr 20, 2022 at 05:43:41AM -0700, Georgi Djakov wrote:

From: Anshuman Khandual anshuman.khandual@arm.com

[ Upstream commit 3de360c3fdb34fbdbaf6da3af94367d3fded95d3 ]

CONFIG_SPARSEMEM_VMEMMAP is now the only available memory model on arm64 platforms and free_unused_memmap() would just return without creating any holes in the memmap mapping. There is no need for any special handling in pfn_valid() and HAVE_ARCH_PFN_VALID can just be dropped. This also moves the pfn upper bits sanity check into generic pfn_valid().

It's not clear why we need this patch in stable.