of: Allow mem_reserve of memory with a base address of zero
authorAl Cooper <alcooperx@gmail.com>
Wed, 6 Aug 2014 20:30:04 +0000 (16:30 -0400)
committerGrant Likely <grant.likely@linaro.org>
Sat, 16 Aug 2014 08:02:52 +0000 (09:02 +0100)
commitb5f2a8c02697c3685ccbbb66495465742ffa0dc1
tree4f9e991bbfc38faf4c4ae2afcd36582494309840
parentc9d26423e56ce1ab4d786f92aebecf859d419293
of: Allow mem_reserve of memory with a base address of zero

__reserved_mem_reserve_reg() won't reserve memory if the base address
is zero. This change removes the check for a base address of zero and
allows it to be reserved.

Allowing the first 4K of memory to be reserved will help solve a
problem on some ARM systems where the the first 16K of memory is
unused and becomes allocable memory. This will prevent this memory
from being used for DMA by drivers like the USB OHCI driver which
consider a physical address of zero to be illegal.

Cc: stable@vger.kernel.org # 3.15+
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
drivers/of/fdt.c