A problem when using 2nd stage booting on mvebu is that the first bootloader
already switched the register window location from 0xd0000000 to
0xf1000000 by writing to 0xd0000080. When the second bootloader also
tries to do this switch it writes to the wrong location resulting in an
exception and so a boot failure.

For this reason the base address of the register window is passed in the
barebox header and picked up from there by early code. In a further
patch bootm is taught to put the actual position of the window there for
the second bootloader to finally make second stage booting work.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Status quo is that initially a size of 64 MiB is assumed (which is also
used to determine the size of the malloc area) and then later the dtb
is fixed up with the actually available RAM which is then used.

Instead detect the real RAM size earlier and don't fixup the device tree.
The device tree is fixed up instead by generic code. This way the malloc
area is more appropriately sized and RAM detection is more similar to mach-imx
which is both nice.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

This replaces the reset_cpu() function which every SoC or board must
provide with registered handlers. This makes it possible to have multiple
reset functions for boards which have multiple ways to reset the machine.
Also boards which have no way at all to reset the machine no longer
have to provide a dummy reset_cpu() function.

The problem this solves is that some machines have external PMICs or
similar to reset the system which have to be preferred over the
internal SoC reset, because the PMIC can reset not only the SoC but also
the external devices.

To pick the right way to reset a machine each handler has a priority. The
default priority is 100 and all currently existing restart handlers are
registered with this priority. of_get_restart_priority() allows to retrieve
the priority from the device tree which makes it possible for boards to
give certain restart handlers a higher priority in order to use this one
instead of the default one.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

The initialisation of the memory nodes on mvebu is a bit
compilcated:

pure_initcall(mvebu_memory_fixup_register)
	of_register_fixup(mvebu_memory_of_fixup, NULL)
core_initcall(kirkwood_init_soc)
	mvebu_set_memory()
core_initcall(of_arm_init)
	of_fix_tree()
		mvebu_memory_of_fixup()

First a mvebu common of_fixup function is registered, then the SoC
calls mvebu_set_memory which stores the memory base and size in global
variables. Afterwards the of_fixup is executed which fixes the memory
nodes according to the global variables.

Instead register a SoC specific fixup which directly calls mvebu_set_memory
with the memory base and size as arguments:

pure_initcall(kirkwood_register_soc_fixup);
	of_register_fixup(kirkwood_init_soc, NULL);
core_initcall(of_arm_init)
	of_fix_tree()
		kirkwood_init_soc()
			mvebu_set_memory(phys_base, phys_size);

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

mvebu has a reset_cpu function per SoC this does not work when multiple
SoCs are selected, so add a common reset_cpu function which calls into
the SoC specific ones.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

On Marvell MVEBU SoCs memory size is set up by BootROM and can be read
from SoC's RAM controller. With early DT fixups available, set corresponding
DT node to reflect accessible amount of directly attached RAM.

This patch also removes non-DT call to arm_add_mem_device to silence a
warning about request_region conflict due to adding a mem device twice.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

At early stage after boot, all MVEBU SoCs are similar enough to have
a common lowlevel and barebox entry. We  also remap the internal register
base address to 0xf100000 as it gives some 512M more of contiguous address
space. As we cannot determine real memory size that early, we start with
a default memory size of 64M and probe correct size later in SoC init.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>