[U-Boot] [PATCH] arc: implement slave cores kick-start for Linux kernel

[Alexey Brodkin]

On Wed, 2015-07-01 at 17:03 +0300, Alexey Brodkin wrote:
> With new SMP-enabled CPUs with ARC HS38 cores and corresponding 
> support
> in Linux kernel it's required to add basic SMP support in U-Boot.
> 
> Currently we assume the one and only core starts execution after
> power-on. So most of things in U-Boot is handled in UP mode.
> 
> But when U-Boot is used for loading and starting Linux kernel right
> before jumping to kernel's entry point U-Boot:
>  [1] Sets all slave cores to jump to the same address [kernel's entry
> point]
>  [2] Really starts all slav cores
> 
> In ARC's implemetation of SMP in Linux kernel all cores are supposed 
> to
> run the same start-up code. But only core with ID 0 (master core)
> processes further while others are looping waiting for master core to
> complete some initialization.
> 
> That means it's safe to un-pause slave cores and let them execute 
> kernel
> - they will wait for master anyway.
> 
> Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
> Cc: Vineet Gupta <vgupta at synopsys.com>
> ---
>  arch/arc/lib/bootm.c           |  6 ++++++
>  board/synopsys/axs101/axs101.c | 30 ++++++++++++++++++++++++++++++
>  2 files changed, 36 insertions(+)

Applied, thanks.

-Alexey