Commit 8b6f2499 authored by Lorenzo Pieralisi's avatar Lorenzo Pieralisi Committed by Russell King
Browse files

ARM: 8511/1: ARM64: kernel: PSCI: move PSCI idle management code to drivers/firmware 



ARM64 PSCI kernel interfaces that initialize idle states and implement
the suspend API to enter them are generic and can be shared with the
ARM architecture.

To achieve that goal, this patch moves ARM64 PSCI idle management
code to drivers/firmware, so that the interface to initialize and
enter idle states can actually be shared by ARM and ARM64 arches
back-ends.

The ARM generic CPUidle implementation also requires the definition of
a cpuidle_ops section entry for the kernel to initialize the CPUidle
operations at boot based on the enable-method (ie ARM64 has the
statically initialized cpu_ops counterparts for that purpose); therefore
this patch also adds the required section entry on CONFIG_ARM for PSCI so
that the kernel can initialize the PSCI CPUidle back-end when PSCI is
the probed enable-method.

On ARM64 this patch provides no functional change.

Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arch/arm64]
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Tested-by: default avatarJisheng Zhang <jszhang@marvell.com>
Cc: Will Deacon <will.deacon@arm.com>
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: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 1b9bdf5c

arch/arm/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -2110,7 +2110,7 @@ config ARCH_SUSPEND_POSSIBLE 
	def_bool y



config ARM_CPU_SUSPEND

	def_bool PM_SLEEP || BL_SWITCHER

	def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW

	depends on ARCH_SUSPEND_POSSIBLE



config ARCH_HIBERNATION_POSSIBLE

arch/arm64/kernel/psci.c

+2 −97
Original line number Diff line number Diff line
@@ -20,7 +20,6 @@ 
#include <linux/smp.h>

#include <linux/delay.h>

#include <linux/psci.h>

#include <linux/slab.h>



#include <uapi/linux/psci.h>
@@ -28,73 +27,6 @@ 
#include <asm/cpu_ops.h>

#include <asm/errno.h>

#include <asm/smp_plat.h>

#include <asm/suspend.h>



static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);



static int __maybe_unused cpu_psci_cpu_init_idle(unsigned int cpu)

{

	int i, ret, count = 0;

	u32 *psci_states;

	struct device_node *state_node, *cpu_node;



	cpu_node = of_get_cpu_node(cpu, NULL);

	if (!cpu_node)

		return -ENODEV;



	/*

	 * If the PSCI cpu_suspend function hook has not been initialized

	 * idle states must not be enabled, so bail out

	 */

	if (!psci_ops.cpu_suspend)

		return -EOPNOTSUPP;



	/* Count idle states */

	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",

					      count))) {

		count++;

		of_node_put(state_node);

	}



	if (!count)

		return -ENODEV;



	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);

	if (!psci_states)

		return -ENOMEM;



	for (i = 0; i < count; i++) {

		u32 state;



		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);



		ret = of_property_read_u32(state_node,

					   "arm,psci-suspend-param",

					   &state);

		if (ret) {

			pr_warn(" * %s missing arm,psci-suspend-param property\n",

				state_node->full_name);

			of_node_put(state_node);

			goto free_mem;

		}



		of_node_put(state_node);

		pr_debug("psci-power-state %#x index %d\n", state, i);

		if (!psci_power_state_is_valid(state)) {

			pr_warn("Invalid PSCI power state %#x\n", state);

			ret = -EINVAL;

			goto free_mem;

		}

		psci_states[i] = state;

	}

	/* Idle states parsed correctly, initialize per-cpu pointer */

	per_cpu(psci_power_state, cpu) = psci_states;

	return 0;



free_mem:

	kfree(psci_states);

	return ret;

}



static int __init cpu_psci_cpu_init(unsigned int cpu)

{
@@ -178,38 +110,11 @@ static int cpu_psci_cpu_kill(unsigned int cpu) 
}

#endif



static int psci_suspend_finisher(unsigned long index)

{

	u32 *state = __this_cpu_read(psci_power_state);



	return psci_ops.cpu_suspend(state[index - 1],

				    virt_to_phys(cpu_resume));

}



static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)

{

	int ret;

	u32 *state = __this_cpu_read(psci_power_state);

	/*

	 * idle state index 0 corresponds to wfi, should never be called

	 * from the cpu_suspend operations

	 */

	if (WARN_ON_ONCE(!index))

		return -EINVAL;



	if (!psci_power_state_loses_context(state[index - 1]))

		ret = psci_ops.cpu_suspend(state[index - 1], 0);

	else

		ret = cpu_suspend(index, psci_suspend_finisher);



	return ret;

}



const struct cpu_operations cpu_psci_ops = {

	.name		= "psci",

#ifdef CONFIG_CPU_IDLE

	.cpu_init_idle	= cpu_psci_cpu_init_idle,

	.cpu_suspend	= cpu_psci_cpu_suspend,

	.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,

drivers/firmware/psci.c

+120 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#define pr_fmt(fmt) "psci: " fmt



#include <linux/arm-smccc.h>

#include <linux/cpuidle.h>

#include <linux/errno.h>

#include <linux/linkage.h>

#include <linux/of.h>
@@ -21,10 +22,12 @@ 
#include <linux/printk.h>

#include <linux/psci.h>

#include <linux/reboot.h>

#include <linux/slab.h>

#include <linux/suspend.h>



#include <uapi/linux/psci.h>



#include <asm/cpuidle.h>

#include <asm/cputype.h>

#include <asm/system_misc.h>

#include <asm/smp_plat.h>
@@ -244,6 +247,123 @@ static int __init psci_features(u32 psci_func_id) 
			      psci_func_id, 0, 0);

}



#ifdef CONFIG_CPU_IDLE

static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);



static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)

{

	int i, ret, count = 0;

	u32 *psci_states;

	struct device_node *state_node;



	/*

	 * If the PSCI cpu_suspend function hook has not been initialized

	 * idle states must not be enabled, so bail out

	 */

	if (!psci_ops.cpu_suspend)

		return -EOPNOTSUPP;



	/* Count idle states */

	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",

					      count))) {

		count++;

		of_node_put(state_node);

	}



	if (!count)

		return -ENODEV;



	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);

	if (!psci_states)

		return -ENOMEM;



	for (i = 0; i < count; i++) {

		u32 state;



		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);



		ret = of_property_read_u32(state_node,

					   "arm,psci-suspend-param",

					   &state);

		if (ret) {

			pr_warn(" * %s missing arm,psci-suspend-param property\n",

				state_node->full_name);

			of_node_put(state_node);

			goto free_mem;

		}



		of_node_put(state_node);

		pr_debug("psci-power-state %#x index %d\n", state, i);

		if (!psci_power_state_is_valid(state)) {

			pr_warn("Invalid PSCI power state %#x\n", state);

			ret = -EINVAL;

			goto free_mem;

		}

		psci_states[i] = state;

	}

	/* Idle states parsed correctly, initialize per-cpu pointer */

	per_cpu(psci_power_state, cpu) = psci_states;

	return 0;



free_mem:

	kfree(psci_states);

	return ret;

}



int psci_cpu_init_idle(unsigned int cpu)

{

	struct device_node *cpu_node;

	int ret;



	cpu_node = of_get_cpu_node(cpu, NULL);

	if (!cpu_node)

		return -ENODEV;



	ret = psci_dt_cpu_init_idle(cpu_node, cpu);



	of_node_put(cpu_node);



	return ret;

}



static int psci_suspend_finisher(unsigned long index)

{

	u32 *state = __this_cpu_read(psci_power_state);



	return psci_ops.cpu_suspend(state[index - 1],

				    virt_to_phys(cpu_resume));

}



int psci_cpu_suspend_enter(unsigned long index)

{

	int ret;

	u32 *state = __this_cpu_read(psci_power_state);

	/*

	 * idle state index 0 corresponds to wfi, should never be called

	 * from the cpu_suspend operations

	 */

	if (WARN_ON_ONCE(!index))

		return -EINVAL;



	if (!psci_power_state_loses_context(state[index - 1]))

		ret = psci_ops.cpu_suspend(state[index - 1], 0);

	else

		ret = cpu_suspend(index, psci_suspend_finisher);



	return ret;

}



/* ARM specific CPU idle operations */

#ifdef CONFIG_ARM

static struct cpuidle_ops psci_cpuidle_ops __initdata = {

	.suspend = psci_cpu_suspend_enter,

	.init = psci_dt_cpu_init_idle,

};



CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops);

#endif

#endif



static int psci_system_suspend(unsigned long unused)

{

	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),

include/linux/psci.h

+3 −0
Original line number Diff line number Diff line
@@ -24,6 +24,9 @@ bool psci_tos_resident_on(int cpu); 
bool psci_power_state_loses_context(u32 state);

bool psci_power_state_is_valid(u32 state);



int psci_cpu_init_idle(unsigned int cpu);

int psci_cpu_suspend_enter(unsigned long index);



struct psci_operations {

	int (*cpu_suspend)(u32 state, unsigned long entry_point);

	int (*cpu_off)(u32 state);

CRA Git | Maintained and supported by SUSTech CRA and CCSE