BugLink: http://bugs.launchpad.net/bugs/1558330

commit d7d5a43c upstream.

When the Crypto SRAM mappings were added to the Device Tree files
describing the Armada XP boards in commit c466d997 ("ARM: mvebu:
define crypto SRAM ranges for all armada-xp boards"), the fact that
those mappings were overlaping with the PCIe memory aperture was
overlooked. Due to this, we currently have for all Armada XP platforms
a situation that looks like this:

Memory mapping on Armada XP boards with internal registers at
0xf1000000:

 - 0x00000000 -> 0xf0000000	3.75G 	RAM
 - 0xf0000000 -> 0xf1000000	16M	NOR flashes (AXP GP / AXP DB)
 - 0xf1000000 -> 0xf1100000	1M	internal registers
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory aperture
 - 0xf8100000 -> 0xf8110000	64KB	Crypto SRAM #0	=> OVERLAPS WITH PCIE !
 - 0xf8110000 -> 0xf8120000	64KB	Crypto SRAM #1	=> OVERLAPS WITH PCIE !
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O aperture
 - 0xfff0000  -> 0xffffffff	1M	BootROM

The overlap means that when PCIe devices are added, depending on their
memory window needs, they might or might not be mapped into the
physical address space. Indeed, they will not be mapped if the area
allocated in the PCIe memory aperture by the PCI core overlaps with
one of the Crypto SRAM. Typically, a Intel IGB PCIe NIC that needs 8MB
of PCIe memory will see its PCIe memory window allocated from
0xf80000000 for 8MB, which overlaps with the Crypto SRAM windows. Due
to this, the PCIe window is not created, and any attempt to access the
PCIe window makes the kernel explode:

[    3.302213] igb: Copyright (c) 2007-2014 Intel Corporation.
[    3.307841] pci 0000:00:09.0: enabling device (0140 -> 0143)
[    3.313539] mvebu_mbus: cannot add window '4:f8', conflicts with another window
[    3.320870] mvebu-pcie soc:pcie-controller: Could not create MBus window at [mem 0xf8000000-0xf87fffff]: -22
[    3.330811] Unhandled fault: external abort on non-linefetch (0x1008) at 0xf08c0018

This problem does not occur on Armada 370 boards, because we use the
following memory mapping (for boards that have internal registers at
0xf1000000):

 - 0x00000000 -> 0xf0000000	3.75G 	RAM
 - 0xf0000000 -> 0xf1000000	16M	NOR flashes (AXP GP / AXP DB)
 - 0xf1000000 -> 0xf1100000	1M	internal registers
 - 0xf1100000 -> 0xf1110000	64KB	Crypto SRAM #0 => OK !
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O
 - 0xfff0000  -> 0xffffffff	1M	BootROM

Obviously, the solution is to align the location of the Crypto SRAM
mappings of Armada XP to be similar with the ones on Armada 370, i.e
have them between the "internal registers" area and the beginning of
the PCIe aperture.

However, we have a special case with the OpenBlocks AX3-4 platform,
which has a 128 MB NOR flash. Currently, this NOR flash is mapped from
0xf0000000 to 0xf8000000. This is possible because on OpenBlocks
AX3-4, the internal registers are not at 0xf1000000. And this explains
why the Crypto SRAM mappings were not configured at the same place on
Armada XP.

Hence, the solution is two-fold:

 (1) Move the NOR flash mapping on Armada XP OpenBlocks AX3-4 from
     0xe8000000 to 0xf0000000. This frees the 0xf0000000 ->
     0xf80000000 space.

 (2) Move the Crypto SRAM mappings on Armada XP to be similar to
     Armada 370 (except of course that Armada XP has two Crypto SRAM
     and not one).

After this patch, the memory mapping on Armada XP boards with
registers at 0xf1 is:

 - 0x00000000 -> 0xf0000000	3.75G 	RAM
 - 0xf0000000 -> 0xf1000000	16M	NOR flashes (AXP GP / AXP DB)
 - 0xf1000000 -> 0xf1100000	1M	internal registers
 - 0xf1100000 -> 0xf1110000	64KB	Crypto SRAM #0
 - 0xf1110000 -> 0xf1120000	64KB	Crypto SRAM #1
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O
 - 0xfff0000  -> 0xffffffff	1M	BootROM

And the memory mapping for the special case of the OpenBlocks AX3-4
(internal registers at 0xd0000000, NOR of 128 MB):

 - 0x00000000 -> 0xc0000000	3G 	RAM
 - 0xd0000000 -> 0xd1000000	1M	internal registers
 - 0xe800000  -> 0xf0000000	128M	NOR flash
 - 0xf1100000 -> 0xf1110000	64KB	Crypto SRAM #0
 - 0xf1110000 -> 0xf1120000	64KB	Crypto SRAM #1
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O
 - 0xfff0000  -> 0xffffffff	1M	BootROM

Fixes: c466d997 ("ARM: mvebu: define crypto SRAM ranges for all armada-xp boards")
Reported-by: Phil Sutter <phil@nwl.cc>
Cc: Phil Sutter <phil@nwl.cc>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>