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From: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] arc: implement slave cores kick-start for Linux kernel
Date: Wed, 1 Jul 2015 14:21:11 +0000	[thread overview]
Message-ID: <1435760471.4689.52.camel@synopsys.com> (raw)
In-Reply-To: <1435759418-30207-1-git-send-email-abrodkin@synopsys.com>

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@synopsys.com>
> Cc: Vineet Gupta <vgupta@synopsys.com>
> ---
>  arch/arc/lib/bootm.c           |  6 ++++++
>  board/synopsys/axs101/axs101.c | 30 ++++++++++++++++++++++++++++++
>  2 files changed, 36 insertions(+)

Applied, thanks.

-Alexey

      reply	other threads:[~2015-07-01 14:21 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-01 14:03 [U-Boot] [PATCH] arc: implement slave cores kick-start for Linux kernel Alexey Brodkin
2015-07-01 14:21 ` Alexey Brodkin [this message]

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