[PATCH v4 06/14] cpuidle: psci: Simplify OF parsing of CPU idle state nodes

[Ulf Hansson <ulf.hansson@xxxxxxxxxx>]

Iterating through the idle state nodes in DT, to find out the number of
states that needs to be allocated is unnecessary, as it has already been
done from dt_init_idle_driver(). Therefore, drop the iteration and use the
number we already have at hand.

Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---

Changes in v4:
	- None.

---
 drivers/cpuidle/cpuidle-psci.c | 35 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 18 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index 361985f52ddd..761359be50f2 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -73,30 +73,24 @@ static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state)
 	return 0;
 }
 
-static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
+static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node,
+					unsigned int state_count, int cpu)
 {
-	int i, ret = 0, count = 0;
+	int i, ret = 0;
 	u32 *psci_states;
 	struct device_node *state_node;
 
-	/* 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;
-
-	count++; /* Add WFI state too */
-	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
+	state_count++; /* Add WFI state too */
+	psci_states = kcalloc(state_count, sizeof(*psci_states), GFP_KERNEL);
 	if (!psci_states)
 		return -ENOMEM;
 
-	for (i = 1; i < count; i++) {
+	for (i = 1; i < state_count; i++) {
 		state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
 					      i - 1);
+		if (!state_node)
+			break;
+
 		ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
 		of_node_put(state_node);
 
@@ -106,6 +100,11 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
 		pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
 	}
 
+	if (i != state_count) {
+		ret = -ENODEV;
+		goto free_mem;
+	}
+
 	/* Idle states parsed correctly, initialize per-cpu pointer */
 	per_cpu(psci_power_state, cpu) = psci_states;
 	return 0;
@@ -115,7 +114,7 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
 	return ret;
 }
 
-static __init int psci_cpu_init_idle(unsigned int cpu)
+static __init int psci_cpu_init_idle(unsigned int cpu, unsigned int state_count)
 {
 	struct device_node *cpu_node;
 	int ret;
@@ -131,7 +130,7 @@ static __init int psci_cpu_init_idle(unsigned int cpu)
 	if (!cpu_node)
 		return -ENODEV;
 
-	ret = psci_dt_cpu_init_idle(cpu_node, cpu);
+	ret = psci_dt_cpu_init_idle(cpu_node, state_count, cpu);
 
 	of_node_put(cpu_node);
 
@@ -187,7 +186,7 @@ static int __init psci_idle_init_cpu(int cpu)
 	/*
 	 * Initialize PSCI idle states.
 	 */
-	ret = psci_cpu_init_idle(cpu);
+	ret = psci_cpu_init_idle(cpu, ret);
 	if (ret) {
 		pr_err("CPU %d failed to PSCI idle\n", cpu);
 		goto out_kfree_drv;
-- 
2.17.1