Re: [PATCH v10 15/27] drivers: firmware: psci: Announce support for OS initiated suspend mode

From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Ulf Hansson <ulf.hansson@linaro.org>,
	"Rafael J . Wysocki" <rjw@rjwysocki.net>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-pm@vger.kernel.org
Cc: Vincent Guittot <vincent.guittot@linaro.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Kevin Hilman <khilman@kernel.org>,
	Stephen Boyd <sboyd@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	linux-kernel@vger.kernel.org, Lina Iyer <ilina@codeaurora.org>,
	Tony Lindgren <tony@atomide.com>,
	linux-arm-msm@vger.kernel.org,
	"Raju P . L . S . S . S . N" <rplsssn@codeaurora.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v10 15/27] drivers: firmware: psci: Announce support for OS initiated suspend mode
Date: Thu, 20 Dec 2018 14:11:00 +0100	[thread overview]
Message-ID: <b333c9db-9ef0-cdba-093e-6735a23ec5f6@linaro.org> (raw)
In-Reply-To: <20181129174700.16585-16-ulf.hansson@linaro.org>

On 29/11/2018 18:46, Ulf Hansson wrote:
> PSCI firmware v1.0+, supports two different modes for CPU_SUSPEND. The
> Platform Coordinated mode, which is the default and mandatory mode, while
> support for the OS initiated mode is optional.
> 
> This change introduces initial support for the OS initiated mode, in way
> that it adds the related PSCI bits from the spec and prints a message in
> the log to inform whether the mode is supported by the PSCI FW.
> 
> Cc: Lina Iyer <ilina@codeaurora.org>
> Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

> ---
> 
> Changes in v10:
> 	- None.
> 
> ---
>  drivers/firmware/psci/psci.c | 21 ++++++++++++++++++++-
>  include/uapi/linux/psci.h    |  5 +++++
>  2 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index 6bfa47cbd174..4f0cbc95e41b 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -95,6 +95,11 @@ static inline bool psci_has_ext_power_state(void)
>  				PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
>  }
>  
> +static inline bool psci_has_osi_support(void)
> +{
> +	return psci_cpu_suspend_feature & PSCI_1_0_OS_INITIATED;
> +}
> +
>  static inline bool psci_power_state_loses_context(u32 state)
>  {
>  	const u32 mask = psci_has_ext_power_state() ?
> @@ -659,10 +664,24 @@ static int __init psci_0_1_init(struct device_node *np)
>  	return 0;
>  }
>  
> +static int __init psci_1_0_init(struct device_node *np)
> +{
> +	int err;
> +
> +	err = psci_0_2_init(np);
> +	if (err)
> +		return err;
> +
> +	if (psci_has_osi_support())
> +		pr_info("OSI mode supported.\n");
> +
> +	return 0;
> +}
> +
>  static const struct of_device_id psci_of_match[] __initconst = {
>  	{ .compatible = "arm,psci",	.data = psci_0_1_init},
>  	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
> -	{ .compatible = "arm,psci-1.0",	.data = psci_0_2_init},
> +	{ .compatible = "arm,psci-1.0",	.data = psci_1_0_init},
>  	{},
>  };
>  
> diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
> index b3bcabe380da..581f72085c33 100644
> --- a/include/uapi/linux/psci.h
> +++ b/include/uapi/linux/psci.h
> @@ -49,6 +49,7 @@
>  
>  #define PSCI_1_0_FN_PSCI_FEATURES		PSCI_0_2_FN(10)
>  #define PSCI_1_0_FN_SYSTEM_SUSPEND		PSCI_0_2_FN(14)
> +#define PSCI_1_0_FN_SET_SUSPEND_MODE		PSCI_0_2_FN(15)
>  
>  #define PSCI_1_0_FN64_SYSTEM_SUSPEND		PSCI_0_2_FN64(14)
>  
> @@ -97,6 +98,10 @@
>  #define PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK	\
>  			(0x1 << PSCI_1_0_FEATURES_CPU_SUSPEND_PF_SHIFT)
>  
> +#define PSCI_1_0_OS_INITIATED			BIT(0)
> +#define PSCI_1_0_SUSPEND_MODE_PC		0
> +#define PSCI_1_0_SUSPEND_MODE_OSI		1
> +
>  /* PSCI return values (inclusive of all PSCI versions) */
>  #define PSCI_RET_SUCCESS			0
>  #define PSCI_RET_NOT_SUPPORTED			-1
> 


-- 
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel