[v5,09/15] cpuidle: psci: Attach CPU devices to their PM domains

Message ID 20191230144402.30195-10-ulf.hansson@linaro.org
State Accepted
Commit 8554951a4dd3d3a1a0efeba8eb5543eee7533be4
Headers show
Series
  • cpuidle: psci: Support hierarchical CPU arrangement
Related show

Commit Message

Ulf Hansson Dec. 30, 2019, 2:43 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>

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>

---

Changes in v5:
	- None.

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

-- 
2.17.1

Patch

diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index 830995b8a56f..6a87848be3c3 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]);
@@ -79,6 +85,7 @@  static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node,
 	int i, ret = 0;
 	u32 *psci_states;
 	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 +111,17 @@  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;
+	/* Currently limit the hierarchical topology to be used in OSI mode. */
+	if (psci_has_osi_support()) {
+		data->dev = psci_dt_attach_cpu(cpu);
+		if (IS_ERR(data->dev)) {
+			ret = PTR_ERR(data->dev);
+			goto free_mem;
+		}
+	}
+
+	/* Idle states parsed correctly, store them in the per-cpu struct. */
+	data->psci_states = psci_states;
 	return 0;
 
 free_mem: