ARM: psci: cpuidle: Enable PSCI CPUidle driver

Allow selection of the PSCI CPUidle in the kernel by updating
the respective Kconfig entry.

Remove PSCI callbacks from ARM/ARM64 generic CPU ops
to prevent the PSCI idle driver from clashing with the generic
ARM CPUidle driver initialization, that relies on CPU ops
to initialize and enter idle states.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/kernel/cpuidle.c

@@ -11,6 +11,7 @@
 #include <linux/cpu_pm.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/psci.h>
 
 #include <asm/cpuidle.h>
 #include <asm/cpu_ops.h>
@@ -48,15 +49,15 @@ int arm_cpuidle_suspend(int index)
 
 int acpi_processor_ffh_lpi_probe(unsigned int cpu)
 {
-	return arm_cpuidle_init(cpu);
+	return psci_cpu_init_idle(cpu);
 }
 
 int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
 {
 	if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags))
-		return CPU_PM_CPU_IDLE_ENTER_RETENTION(arm_cpuidle_suspend,
+		return CPU_PM_CPU_IDLE_ENTER_RETENTION(psci_cpu_suspend_enter,
 						lpi->index);
 	else
-		return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, lpi->index);
+		return CPU_PM_CPU_IDLE_ENTER(psci_cpu_suspend_enter, lpi->index);
 }
 #endif

arch/arm64/kernel/psci.c

@@ -105,10 +105,6 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
 
 const struct cpu_operations cpu_psci_ops = {
 	.name		= "psci",
-#ifdef CONFIG_CPU_IDLE
-	.cpu_init_idle	= psci_cpu_init_idle,
-	.cpu_suspend	= psci_cpu_suspend_enter,
-#endif
 	.cpu_init	= cpu_psci_cpu_init,
 	.cpu_prepare	= cpu_psci_cpu_prepare,
 	.cpu_boot	= cpu_psci_cpu_boot,

drivers/cpuidle/Kconfig.arm

@@ -14,7 +14,7 @@ config ARM_CPUIDLE
           provided by architecture code.
 
 config ARM_PSCI_CPUIDLE
-	bool
+	bool "PSCI CPU idle Driver"
 	depends on ARM_PSCI_FW
 	select DT_IDLE_STATES
 	select CPU_IDLE_MULTIPLE_DRIVERS

drivers/firmware/psci/psci.c

@@ -436,16 +436,6 @@ int psci_cpu_suspend_enter(unsigned long index)
 
 	return ret;
 }
-
-/* ARM specific CPU idle operations */
-#ifdef CONFIG_ARM
-static const struct cpuidle_ops psci_cpuidle_ops __initconst = {
-	.suspend = psci_cpu_suspend_enter,
-	.init = psci_dt_cpu_init_idle,
-};
-
-CPUIDLE_METHOD_OF_DECLARE(psci, "psci", &psci_cpuidle_ops);
-#endif
 #endif
 
 static int psci_system_suspend(unsigned long unused)