Subject: [PATCH 2/2] arm: add early_ioremap support

From: [email-masked] (Tomasz Figa)
Date: Tue, 22 Jul 2014 18:48:02 +0200

Hi Leif,

On 09.07.2014 11:39, Leif Lindholm wrote:
> From: Mark Salter <[email-masked]>
> 
> This patch uses the generic early_ioremap code to implement
> early_ioremap for ARM. The ARM-specific bits come mostly from
> an earlier patch from Leif Lindholm <[email-masked]>
> here:
> 
>   https://lkml.org/lkml/2013/10/3/279

[snip]

> diff --git a/arch/arm/mm/early_ioremap.c b/arch/arm/mm/early_ioremap.c
> new file mode 100644
> index 0000000..1013109
> --- /dev/null
> +++ b/arch/arm/mm/early_ioremap.c
> @@ -0,0 +1,86 @@
> +/*
> + * early_ioremap() support for ARM
> + *
> + * Based on existing support in arch/x86/mm/ioremap.c
> + *
> + * Restrictions: currently only functional before paging_init()

Uhm, that's bad... This would explain why my earlycon code generates a
fault as soon as something prints after paging_init(). I'd say this
feature would be much more useful if mappings were carried over
paging_init(), so that mapped devices are available later as well.

I'll see if I can code this on top of your patch, but unfortunately it
might end up with -ENOTIME.

Best regards,
Tomasz