[PATCH 00/03] ARM: 64-bit memory fixes, APE6EVM second memory bank

[Guennadi Liakhovetski]

On Wed, 5 Jun 2013, Magnus Damm wrote:

> ARM: 64-bit memory fixes, APE6EVM second memory bank
> 
> [PATCH 01/03] ARM: Let arm_add_memory() always use 64-bit arguments
> [PATCH 02/03] ARM: Handle 64-bit memory in case of 32-bit phys_addr_t
> [PATCH 03/03] ARM: shmobile: Add second memory bank to DTS for APE6EVM
> 
> This patch set contains two fixes and one mach-shmobile specific patch
> to add a second memory bank. The fixes attempt to improve the memory bank
> handling in the ARM kernel in case of 64-bit addresses.
> 
> Without patch 1/3 and 2/3 but with patch 3/3 by itself:
> 
> HIGHMEM=n, LPAE=n - OK (busted, second bank ignored with message [1])
> HIGHMEM=y, LPAE=n - NG (busted, board hangs on boot)
> HIGHMEM=n, LPAE=y - OK
> HIGHMEM=y, LPAE=y - OK
> 
> [1] Ignoring RAM at 00000000-3fffffff (vmalloc region overlap).
> 
> With all patches applied:
> 
> HIGHMEM=n, LPAE=n - OK
> HIGHMEM=y, LPAE=n - OK

Confirmed: these patches fix the LPAE=n case

Tested-by: Guennadi Liakhovetski <g.liakhovetski+renesas at gmail.com>

Thanks
Guennadi

> HIGHMEM=n, LPAE=y - OK
> HIGHMEM=y, LPAE=y - OK
> 
> My opinion is that LPAE should be handled in a similar way to x86 PAE.
> This means the kernel should boot regardless of kernel config but 64-bit
> memory banks may be truncated if needed like when LPAE=n or HIGHMEN=n.
> 
> Comments on how to implement this in a nicer way are very welcome!
> 
> Signed-off-by: Magnus Damm <damm at opensource.se>
> ---
> 
>  Written against renesas.git renesas-next-20130604v2
> 
>  arch/arm/boot/dts/r8a73a4-ape6evm.dts |    5 +++++
>  arch/arm/include/asm/setup.h          |    2 +-
>  arch/arm/kernel/setup.c               |   22 +++++++++++++++-------
>  3 files changed, 21 insertions(+), 8 deletions(-)

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/