Re: [PATCH v3 3/3] ARM hibernation / suspend-to-disk

From: Pavel Machek
Date: Thu Feb 27 2014 - 17:18:32 EST


Hi!
On Tue 2014-02-25 16:02:00, Sebastian Capella wrote:
> From: Russ Dill <Russ.Dill@xxxxxx>
>
> Enable hibernation for ARM architectures and provide ARM
> architecture specific calls used during hibernation.
>
> The swsusp hibernation framework depends on the
> platform first having functional suspend/resume.
>
> Then, in order to enable hibernation on a given platform, a
> platform_hibernation_ops structure may need to be registered with
> the system in order to save/restore any SoC-specific / cpu specific
> state needing (re)init over a suspend-to-disk/resume-from-disk cycle.
>
> For example:
>
> - "secure" SoCs that have different sets of control registers
> and/or different CR reg access patterns.
>
> - SoCs with L2 caches as the activation sequence there is
> SoC-dependent; a full off-on cycle for L2 is not done
> by the hibernation support code.
>
> - SoCs requiring steps on wakeup _before_ the "generic" parts
> done by cpu_suspend / cpu_resume can work correctly.
>
> - SoCs having persistent state which is maintained during suspend
> and resume, but will be lost during the power off cycle after
> suspend-to-disk.
>
> This is a rebase/rework of Frank Hofmann's v5 hibernation patchset.
>

> +/*
> + * Snapshot kernel memory and reset the system.
> + * soft_restart is not technically needed, but is used
> + * to get success returned from cpu_suspend.
> + * After resume, the hibernation snapshot is written out.
> + */
> +static int notrace __swsusp_arch_save_image(unsigned long unused)
> +{
> + int ret;
> +
> + ret = swsusp_save();
> + if (ret == 0)
> + soft_restart(virt_to_phys(cpu_resume));
> + return ret;
> +}

This is static, so maybe arch_save_image() is better name?

> +static u8 __swsusp_resume_stk[PAGE_SIZE/2] __nosavedata;

resume_stack?

Thanks,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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