linux-kernel - Re: [PATCH v2 2/7] ARM: EXYNOS: add support for firmware-assisted c15resume

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 02 Jun 2014 14:56:36 +0200
From:	Tomasz Figa <tomasz.figa@...il.com>
To:	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	Kukjin Kim <kgene.kim@...sung.com>
CC:	linux-samsung-soc@...r.kernel.org, linux-pm@...r.kernel.org,
	Sachin Kamat <sachin.kamat@...aro.org>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	Tomasz Figa <t.figa@...sung.com>,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	linux-kernel@...r.kernel.org,
	Kyungmin Park <kyungmin.park@...sung.com>,
	linaro-kernel@...ts.linaro.org,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 2/7] ARM: EXYNOS: add support for firmware-assisted
 c15resume

Hi,

On 02.06.2014 14:35, Bartlomiej Zolnierkiewicz wrote:
> From: Tomasz Figa <t.figa@...sung.com>
> 
> This change is a preparation for adding secure firmware support to
> EXYNOS cpuidle driver.
> 
> This patch shouldn't cause any functionality changes.
> 
> Signed-off-by: Tomasz Figa <t.figa@...sung.com>
> [bzolnier: splitted out from bigger patch]
> Acked-by: Kyungmin Park <kyungmin.park@...sung.com>
> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
> ---
>  arch/arm/include/asm/firmware.h | 4 ++++
>  arch/arm/mach-exynos/firmware.c | 8 ++++++++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/arch/arm/include/asm/firmware.h b/arch/arm/include/asm/firmware.h
> index c72ec47..70883c7 100644
> --- a/arch/arm/include/asm/firmware.h
> +++ b/arch/arm/include/asm/firmware.h
> @@ -41,6 +41,10 @@ struct firmware_ops {
>  	 * Initializes L2 cache
>  	 */
>  	int (*l2x0_init)(void);
> +	/*
> +	 * Restores coprocessor 15 registers
> +	 */
> +	int (*c15resume)(u32 *regs);

Well, this was just a kind of internal hack, so I'm not sure this is
suitable as a generic firmware operation in mainline.

I'd rather implement this as a part of a wider suspend and resume
firmware operations, where suspend would save values of cp15 registers
and resume would restore them.

Best regards,
Tomasz
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/