ARM: 9447/1: arm/memremap: fix arch_memremap_can_ram_remap()

arm/memremap: fix arch_memremap_can_ram_remap()

commit 260364d112bc ("arm[64]/memremap: don't abuse pfn_valid() to ensure
presence of linear map") added the definition of
arch_memremap_can_ram_remap() for arm[64] specific filtering of what pages
can be used from the linear mapping. memblock_is_map_memory() was called
with the pfn of the address given to arch_memremap_can_ram_remap();
however, memblock_is_map_memory() expects to be given an address for arm,
not a pfn.

This results in calls to memremap() returning a newly mapped area when
it should return an address in the existing linear mapping.

Fix this by removing the address to pfn translation and pass the
address directly.

Fixes: 260364d112bc ("arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map")
Signed-off-by: Ross Stutterheim <[e-mail]>
Cc: Mike Rapoport <[e-mail]>
Cc: [e-mail]
Reviewed-by: Catalin Marinas <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Signed-off-by: Russell King (Oracle) <[e-mail]>

arch/arm/mm/ioremap.c

···
 bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
 				 unsigned long flags)
 {
-	unsigned long pfn = PHYS_PFN(offset);
-
-	return memblock_is_map_memory(pfn);
+	return memblock_is_map_memory(offset);
 }