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

commit 96e0b355883006554a0bee3697da475971d6bba8 upstream.

arm/memremap: fix arch_memremap_can_ram_remap()

commit 260364d112 ("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: 260364d112 ("arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map")
Signed-off-by: Ross Stutterheim <ross.stutterheim@garmin.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/mm/ioremap.c

@@ -515,7 +515,5 @@ void __init early_ioremap_init(void)
 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);
 }