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

PATCH New Alim Akhtar 2 participants 3 messages Jan 19, 2016 – Jan 20, 2016

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Alim Akhtar

author reviewer

2016-01-19 10:20 UTC #0 lore raw

PATCH 1/1 arm64: dts: Add PSCI function IDs for cpu-{on, off} on exynos7

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 <[email protected]>

---
 arch/arm64/boot/dts/exynos/exynos7.dtsi |    2 ++
 1 file changed, 2 insertions(+)

arch/arm64/boot/dts/exynos/exynos7.dtsi +2 -0

index f9c5a549c2c0..1a2bb3b453e5 100644
@@ -65,6 +65,8 @@
 	psci {
 		compatible = "arm,psci-0.2";
 		method = "smc";
+		cpu_on = <0xC4000003>;
+		cpu_off = <0x84000002>;
 	};
 
 	soc: soc {

Signature · 1 line

1.7.10.4

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

author reviewer

2016-01-20 02:51 UTC #2 lore raw

PATCH 1/1 arm64: dts: Add PSCI function IDs for cpu-{on,off} on exynos7

Hi Mark,

Quoted 24 lines · Mark Rutland

Quoted 14 lines · Alim Akhtar
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 <[email protected]>
---
  arch/arm64/boot/dts/exynos/exynos7.dtsi |    2 ++
  1 file changed, 2 insertions(+)
arch/arm64/boot/dts/exynos/exynos7.dtsi +0 -0
index f9c5a549c2c0..1a2bb3b453e5 100644
arch/arm64/boot/dts/exynos/exynos7.dtsi line 70
Quoted 6 lines
arch/arm64/boot/dts/exynos/exynos7.dtsi +2 -0
@@ -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.

Quoted 8 lines

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.

Quoted 4 lines

Thanks,
Mark.