[v2,09/13] cpuidle: psci: Attach CPU devices to their PM domains

Message ID 20191029164438.17012-10-ulf.hansson@linaro.org
State Superseded
Headers show
Series
  • cpuidle: psci: Support hierarchical CPU arrangement
Related show

Commit Message

Ulf Hansson Oct. 29, 2019, 4:44 p.m.
In order to enable a CPU to be power managed through its PM domain, let's
try to attach it by calling psci_dt_attach_cpu() during the cpuidle
initialization.

psci_dt_attach_cpu() returns a pointer to the attached struct device, which
later should be used for runtime PM, hence we need to store it somewhere.
Rather than adding yet another per CPU variable, let's create a per CPU
struct to collect the relevant per CPU variables.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

---

Changes in v2:
	- Rebased.

---
 drivers/cpuidle/cpuidle-psci.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

-- 
2.17.1

Comments

Sudeep Holla Nov. 15, 2019, 5:15 p.m. | #1
On Tue, Oct 29, 2019 at 05:44:34PM +0100, Ulf Hansson wrote:
> In order to enable a CPU to be power managed through its PM domain, let's

> try to attach it by calling psci_dt_attach_cpu() during the cpuidle

> initialization.

>

> psci_dt_attach_cpu() returns a pointer to the attached struct device, which

> later should be used for runtime PM, hence we need to store it somewhere.

> Rather than adding yet another per CPU variable, let's create a per CPU

> struct to collect the relevant per CPU variables.

>

> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

> ---

>

> Changes in v2:

> 	- Rebased.

>

> ---

>  drivers/cpuidle/cpuidle-psci.c | 24 ++++++++++++++++++++----

>  1 file changed, 20 insertions(+), 4 deletions(-)

>

> diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c

> index 830995b8a56f..167249d0493f 100644

> --- a/drivers/cpuidle/cpuidle-psci.c

> +++ b/drivers/cpuidle/cpuidle-psci.c

> @@ -20,14 +20,20 @@

>

>  #include <asm/cpuidle.h>

>

> +#include "cpuidle-psci.h"

>  #include "dt_idle_states.h"

>

> -static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);

> +struct psci_cpuidle_data {

> +	u32 *psci_states;

> +	struct device *dev;

> +};

> +

> +static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);

>

>  static int psci_enter_idle_state(struct cpuidle_device *dev,

>  				struct cpuidle_driver *drv, int idx)

>  {

> -	u32 *state = __this_cpu_read(psci_power_state);

> +	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);

>

>  	return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter,

>  					   idx, state[idx]);

> @@ -78,7 +84,9 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node,

>  {

>  	int i, ret = 0;

>  	u32 *psci_states;

> +	struct device *dev;

>  	struct device_node *state_node;

> +	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);

>

>  	state_count++; /* Add WFI state too */

>  	psci_states = kcalloc(state_count, sizeof(*psci_states), GFP_KERNEL);

> @@ -104,8 +112,16 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node,

>  		goto free_mem;

>  	}

>

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

> -	per_cpu(psci_power_state, cpu) = psci_states;

> +	dev = psci_dt_attach_cpu(cpu);


Why do we need to call psci_dt_attach_cpu for even PC mode and ...

> +	if (IS_ERR(dev)) {

> +		ret = PTR_ERR(dev);

> +		goto free_mem;

> +	}

> +

> +	data->dev = dev;

> +


... assign NULL above. I don't see the need for one. Default it will be
NULL anyway and we can call psci_dt_attach_cpu only if psci_has_osi_support()

I will look through further patches to see if it make sense or not.

--
Regards,
Sudeep

Patch

diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index 830995b8a56f..167249d0493f 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -20,14 +20,20 @@ 
 
 #include <asm/cpuidle.h>
 
+#include "cpuidle-psci.h"
 #include "dt_idle_states.h"
 
-static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
+struct psci_cpuidle_data {
+	u32 *psci_states;
+	struct device *dev;
+};
+
+static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
 
 static int psci_enter_idle_state(struct cpuidle_device *dev,
 				struct cpuidle_driver *drv, int idx)
 {
-	u32 *state = __this_cpu_read(psci_power_state);
+	u32 *state = __this_cpu_read(psci_cpuidle_data.psci_states);
 
 	return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter,
 					   idx, state[idx]);
@@ -78,7 +84,9 @@  static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node,
 {
 	int i, ret = 0;
 	u32 *psci_states;
+	struct device *dev;
 	struct device_node *state_node;
+	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
 
 	state_count++; /* Add WFI state too */
 	psci_states = kcalloc(state_count, sizeof(*psci_states), GFP_KERNEL);
@@ -104,8 +112,16 @@  static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node,
 		goto free_mem;
 	}
 
-	/* Idle states parsed correctly, initialize per-cpu pointer */
-	per_cpu(psci_power_state, cpu) = psci_states;
+	dev = psci_dt_attach_cpu(cpu);
+	if (IS_ERR(dev)) {
+		ret = PTR_ERR(dev);
+		goto free_mem;
+	}
+
+	data->dev = dev;
+
+	/* Idle states parsed correctly, store them in the per-cpu struct. */
+	data->psci_states = psci_states;
 	return 0;
 
 free_mem: