PM: EM: Split the allocation and initialization of the EM table

Split the process of allocation and data initialization for the EM table.
The upcoming changes for modifiable EM will use it.

This change is not expected to alter the general functionality.
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/energy_model.c

@@ -142,18 +142,26 @@ static int em_compute_costs(struct device *dev, struct em_perf_state *table,
 	return 0;
 }
 
+static int em_allocate_perf_table(struct em_perf_domain *pd,
+				  int nr_states)
+{
+	pd->table = kcalloc(nr_states, sizeof(struct em_perf_state),
+			    GFP_KERNEL);
+	if (!pd->table)
+		return -ENOMEM;
+
+	return 0;
+}
+
 static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
-				int nr_states, struct em_data_callback *cb,
+				struct em_perf_state *table,
+				struct em_data_callback *cb,
 				unsigned long flags)
 {
 	unsigned long power, freq, prev_freq = 0;
-	struct em_perf_state *table;
+	int nr_states = pd->nr_perf_states;
 	int i, ret;
 
-	table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL);
-	if (!table)
-		return -ENOMEM;
-
 	/* Build the list of performance states for this performance domain */
 	for (i = 0, freq = 0; i < nr_states; i++, freq++) {
 		/*
@@ -165,7 +173,7 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
 		if (ret) {
 			dev_err(dev, "EM: invalid perf. state: %d\n",
 				ret);
-			goto free_ps_table;
+			return -EINVAL;
 		}
 
 		/*
@@ -175,7 +183,7 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
 		if (freq <= prev_freq) {
 			dev_err(dev, "EM: non-increasing freq: %lu\n",
 				freq);
-			goto free_ps_table;
+			return -EINVAL;
 		}
 
 		/*
@@ -185,7 +193,7 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
 		if (!power || power > EM_MAX_POWER) {
 			dev_err(dev, "EM: invalid power: %lu\n",
 				power);
-			goto free_ps_table;
+			return -EINVAL;
 		}
 
 		table[i].power = power;
@@ -194,16 +202,9 @@ static int em_create_perf_table(struct device *dev, struct em_perf_domain *pd,
 
 	ret = em_compute_costs(dev, table, cb, nr_states, flags);
 	if (ret)
-		goto free_ps_table;
-
-	pd->table = table;
-	pd->nr_perf_states = nr_states;
+		return -EINVAL;
 
 	return 0;
-
-free_ps_table:
-	kfree(table);
-	return -EINVAL;
 }
 
 static int em_create_pd(struct device *dev, int nr_states,
@@ -234,11 +235,15 @@ static int em_create_pd(struct device *dev, int nr_states,
 			return -ENOMEM;
 	}
 
-	ret = em_create_perf_table(dev, pd, nr_states, cb, flags);
-	if (ret) {
-		kfree(pd);
-		return ret;
-	}
+	pd->nr_perf_states = nr_states;
+
+	ret = em_allocate_perf_table(pd, nr_states);
+	if (ret)
+		goto free_pd;
+
+	ret = em_create_perf_table(dev, pd, pd->table, cb, flags);
+	if (ret)
+		goto free_pd_table;
 
 	if (_is_cpu_device(dev))
 		for_each_cpu(cpu, cpus) {
@@ -249,6 +254,12 @@ static int em_create_pd(struct device *dev, int nr_states,
 	dev->em_pd = pd;
 
 	return 0;
+
+free_pd_table:
+	kfree(pd->table);
+free_pd:
+	kfree(pd);
+	return -EINVAL;
 }
 
 static void