diff mbox

arm64: dts: Add PSCI function IDs for cpu-{on, off} on exynos7

Message ID 1453198884-28723-1-git-send-email-alim.akhtar@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alim Akhtar Jan. 19, 2016, 10:21 a.m. UTC
This patch adds cpu-{on,off} function IDs as per PSCI specification,
with this we can boot multiple CPUs and can use cpu hotplug on
exynos7 platform.

Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
---
 arch/arm64/boot/dts/exynos/exynos7.dtsi |    2 ++
 1 file changed, 2 insertions(+)

Comments

Mark Rutland Jan. 19, 2016, 10:32 a.m. UTC | #1
On Tue, Jan 19, 2016 at 03:51:24PM +0530, Alim Akhtar wrote:
> This patch adds cpu-{on,off} function IDs as per PSCI specification,
> with this we can boot multiple CPUs and can use cpu hotplug on
> exynos7 platform.
> 
> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
> ---
>  arch/arm64/boot/dts/exynos/exynos7.dtsi |    2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/exynos/exynos7.dtsi b/arch/arm64/boot/dts/exynos/exynos7.dtsi
> index f9c5a549c2c0..1a2bb3b453e5 100644
> --- a/arch/arm64/boot/dts/exynos/exynos7.dtsi
> +++ b/arch/arm64/boot/dts/exynos/exynos7.dtsi
> @@ -65,6 +65,8 @@
>  	psci {
>  		compatible = "arm,psci-0.2";
>  		method = "smc";
> +		cpu_on = <0xC4000003>;
> +		cpu_off = <0x84000002>;
>  	};

There is no need for this patch.

The "arm,psci-0.2" compatible string implicitly tells the kernel that
the full set of mandatory PSCI 0.2 functions are present, with the IDs
mandated by PSCI 0.2. That includes CPU_ON and CPU_OFF amongst others.

The only reason to provide IDs is to function on kernels without PSCI
0.2 support. Given the compatible string hasn't been updated for that,
this is insufficient for that case.

Thanks,
Mark.
Alim Akhtar Jan. 20, 2016, 2:52 a.m. UTC | #2
Hi Mark,

On 01/19/2016 04:02 PM, Mark Rutland wrote:
> On Tue, Jan 19, 2016 at 03:51:24PM +0530, Alim Akhtar wrote:
>> This patch adds cpu-{on,off} function IDs as per PSCI specification,
>> with this we can boot multiple CPUs and can use cpu hotplug on
>> exynos7 platform.
>>
>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>> ---
>>   arch/arm64/boot/dts/exynos/exynos7.dtsi |    2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/exynos/exynos7.dtsi b/arch/arm64/boot/dts/exynos/exynos7.dtsi
>> index f9c5a549c2c0..1a2bb3b453e5 100644
>> --- a/arch/arm64/boot/dts/exynos/exynos7.dtsi
>> +++ b/arch/arm64/boot/dts/exynos/exynos7.dtsi
>> @@ -65,6 +65,8 @@
>>   	psci {
>>   		compatible = "arm,psci-0.2";
>>   		method = "smc";
>> +		cpu_on = <0xC4000003>;
>> +		cpu_off = <0x84000002>;
>>   	};
>
> There is no need for this patch.
>
> The "arm,psci-0.2" compatible string implicitly tells the kernel that
> the full set of mandatory PSCI 0.2 functions are present, with the IDs
> mandated by PSCI 0.2. That includes CPU_ON and CPU_OFF amongst others.
>
> The only reason to provide IDs is to function on kernels without PSCI
> 0.2 support. Given the compatible string hasn't been updated for that,
> this is insufficient for that case.
>
Ah, right, this patch is not required for psci,0.2, thanks for 
clarification.
sorry for the noise.

> Thanks,
> Mark.
>
>
diff mbox

Patch

diff --git a/arch/arm64/boot/dts/exynos/exynos7.dtsi b/arch/arm64/boot/dts/exynos/exynos7.dtsi
index f9c5a549c2c0..1a2bb3b453e5 100644
--- a/arch/arm64/boot/dts/exynos/exynos7.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynos7.dtsi
@@ -65,6 +65,8 @@ 
 	psci {
 		compatible = "arm,psci-0.2";
 		method = "smc";
+		cpu_on = <0xC4000003>;
+		cpu_off = <0x84000002>;
 	};
 
 	soc: soc {