Re: [RFC] ARM: add multi_v7_lpae_defconfig

[Florian Fainelli <f.fainelli@gmail.com>]

On 2/12/20 12:19 PM, Arnd Bergmann wrote:
> On Fri, Jan 10, 2020 at 6:35 PM Nicolas Saenz Julienne
> <nsaenzjulienne@suse.de> wrote:
>>
>> The only missing configuration option preventing us from using
>> multi_v7_defconfig with the RPi4 is ARM_LPAE. It's needed as the PCIe
>> controller found on the SoC depends on 64bit addressing, yet can't be
>> included as not all v7 boards support LPAE.
>>
>> Introduce multi_v7_lpae_defconfig, built off multi_v7_defconfig, which will
>> avoid us having to duplicate and maintain multiple similar configurations.
>>
>> Note that merge_into_defconfig was taken from arch/powerpc/Makefile.
>>
>> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> I like the idea, but I would note that a lot of platforms enabled in
> multi_v7_defconfig do not support LPAE. In particular, the first ARMv7
> cores (Cortex-A8, -A9, -A5, and PJ4) don't, but the later ones (Cortex-A7,
> -A15, -A17, and PJ4C-MP) do.
> 
> Here is a list from the defconfig file
> 

[snip]

> CONFIG_ARCH_BCM=y
> CONFIG_ARCH_BCM_CYGNUS=y
> CONFIG_ARCH_BCM_HR2=y
> CONFIG_ARCH_BCM_NSP=y
> CONFIG_ARCH_BCM_5301X=y
> CONFIG_ARCH_BCM_281XX=y
> CONFIG_ARCH_BCM_21664=y
> CONFIG_ARCH_BCM_63XX=y
> CONFIG_ARCH_BRCMSTB=y
> 
> I think most of the above are A9, but not sure

63138 is Cortex-A9, 63148 and BRCMSTB are using a Brahma-B15 CPU which
is LPAE capable. 23550 is A7 and every others are Cortex-A9.
-- 
Florian