arm64: drop pfn_valid_within() and simplify pfn_valid()

The arm64's version of pfn_valid() differs from the generic because of two
reasons:

* Parts of the memory map are freed during boot. This makes it necessary to
  verify that there is actual physical memory that corresponds to a pfn
  which is done by querying memblock.

* There are NOMAP memory regions. These regions are not mapped in the
  linear map and until the previous commit the struct pages representing
  these areas had default values.

As the consequence of absence of the special treatment of NOMAP regions in
the memory map it was necessary to use memblock_is_map_memory() in
pfn_valid() and to have pfn_valid_within() aliased to pfn_valid() so that
generic mm functionality would not treat a NOMAP page as a normal page.

Since the NOMAP regions are now marked as PageReserved(), pfn walkers and
the rest of core mm will treat them as unusable memory and thus
pfn_valid_within() is no longer required at all and can be disabled on
arm64.

pfn_valid() can be slightly simplified by replacing
memblock_is_map_memory() with memblock_is_memory().

[rppt@kernel.org: fix merge fix]
Link: https://lkml.kernel.org/r/YJtoQhidtIJOhYsV@kernel.org
Link: https://lkml.kernel.org/r/20210511100550.28178-5-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 937bdf0..59c9255 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -201,7 +201,6 @@ config ARM64
        select HAVE_KPROBES
        select HAVE_KRETPROBES
        select HAVE_GENERIC_VDSO
-       select HOLES_IN_ZONE
        select IOMMU_DMA if IOMMU_SUPPORT
        select IRQ_DOMAIN
        select IRQ_FORCED_THREADING

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 148e752..725aa84 100644 (file)
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -252,7 +252,7 @@ int pfn_valid(unsigned long pfn)
        if (!early_section(ms))
                return pfn_section_valid(ms, pfn);
 
-       return memblock_is_map_memory(addr);
+       return memblock_is_memory(addr);
 }
 EXPORT_SYMBOL(pfn_valid);