Commit 093bbe21 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Will Deacon
Browse files

arm64/mm: Reorganize pfn_valid() 



There are multiple instances of pfn_to_section_nr() and __pfn_to_section()
when CONFIG_SPARSEMEM is enabled. This can be optimized if memory section
is fetched earlier. This replaces the open coded PFN and ADDR conversion
with PFN_PHYS() and PHYS_PFN() helpers. While there, also add a comment.
This does not cause any functional change.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/1614921898-4099-3-git-send-email-anshuman.khandual@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent eeb0753b

arch/arm64/mm/init.c

+16 −5
Original line number Diff line number Diff line
@@ -219,16 +219,26 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) 


int pfn_valid(unsigned long pfn)

{

	phys_addr_t addr = pfn << PAGE_SHIFT;

	phys_addr_t addr = PFN_PHYS(pfn);



	if ((addr >> PAGE_SHIFT) != pfn)

	/*

	 * Ensure the upper PAGE_SHIFT bits are clear in the

	 * pfn. Else it might lead to false positives when

	 * some of the upper bits are set, but the lower bits

	 * match a valid pfn.

	 */

	if (PHYS_PFN(addr) != pfn)

		return 0;



#ifdef CONFIG_SPARSEMEM

{

	struct mem_section *ms;



	if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)

		return 0;



	if (!valid_section(__pfn_to_section(pfn)))

	ms = __pfn_to_section(pfn);

	if (!valid_section(ms))

		return 0;



	/*
@@ -240,8 +250,9 @@ int pfn_valid(unsigned long pfn) 
	 * memory sections covering all of hotplug memory including

	 * both normal and ZONE_DEVICE based.

	 */

	if (!early_section(__pfn_to_section(pfn)))

		return pfn_section_valid(__pfn_to_section(pfn), pfn);

	if (!early_section(ms))

		return pfn_section_valid(ms, pfn);

}

#endif

	return memblock_is_map_memory(addr);

}