arm64: Don't relocate non-existent initrd

When booting a kernel without an initrd, the kernel reports that it
moves -1 bytes worth, having gone through the motions with initrd_start
equal to initrd_end:

    Moving initrd from [4080000000-407fffffff] to [9fff49000-9fff48fff]

Prevent this by bailing out early when the initrd size is zero (i.e. we
have no initrd), avoiding the confusing message and other associated
work.

Fixes: 1570f0d7ab425c1e ("arm64: support initrd outside kernel linear map")
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 6bab21f84a9ff38402e70345016ed50ae8e95e30..232247945b1c215c25fbfd708573fe3def5c68c5 100644 (file)
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -364,6 +364,8 @@ static void __init relocate_initrd(void)
                to_free = ram_end - orig_start;
 
        size = orig_end - orig_start;
+       if (!size)
+               return;
 
        /* initrd needs to be relocated completely inside linear mapping */
        new_start = memblock_find_in_range(0, PFN_PHYS(max_pfn),