hwmon: (coretemp) Abstract core_temp helpers

coretemp driver has an obscure and fragile logic for handling package
and core temperature data.

Place the logic in newly introduced helpers for further optimizations.

No functional change.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20240202092144.71180-9-rui.zhang@intel.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/coretemp.c

@@ -81,6 +81,7 @@ struct temp_data {
 	int tjmax;
 	unsigned long last_updated;
 	unsigned int cpu;
+	unsigned int index;
 	u32 cpu_core_id;
 	u32 status_reg;
 	int attr_size;
@@ -474,14 +475,36 @@ static struct platform_device *coretemp_get_pdev(unsigned int cpu)
 	return NULL;
 }
 
-static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
+static struct temp_data *
+init_temp_data(struct platform_data *pdata, unsigned int cpu, int pkg_flag)
 {
 	struct temp_data *tdata;
+	int index;
 
 	tdata = kzalloc(sizeof(struct temp_data), GFP_KERNEL);
 	if (!tdata)
 		return NULL;
 
+	/*
+	 * Get the index of tdata in pdata->core_data[]
+	 * tdata for package: pdata->core_data[1]
+	 * tdata for core: pdata->core_data[2] .. pdata->core_data[NUM_REAL_CORES + 1]
+	 */
+	if (pkg_flag) {
+		index = PKG_SYSFS_ATTR_NO;
+	} else {
+		index = ida_alloc_max(&pdata->ida, NUM_REAL_CORES - 1, GFP_KERNEL);
+		if (index < 0) {
+			kfree(tdata);
+			return NULL;
+		}
+		index += BASE_SYSFS_ATTR_NO;
+	}
+	/* Index in pdata->core_data[] */
+	tdata->index = index;
+
+	pdata->core_data[index] = tdata;
+
 	tdata->status_reg = pkg_flag ? MSR_IA32_PACKAGE_THERM_STATUS :
 							MSR_IA32_THERM_STATUS;
 	tdata->is_pkg_data = pkg_flag;
@@ -492,6 +515,30 @@ static struct temp_data *init_temp_data(unsigned int cpu, int pkg_flag)
 	return tdata;
 }
 
+static void destroy_temp_data(struct platform_data *pdata, struct temp_data *tdata)
+{
+	pdata->core_data[tdata->index] = NULL;
+	if (!tdata->is_pkg_data)
+		ida_free(&pdata->ida, tdata->index - BASE_SYSFS_ATTR_NO);
+	kfree(tdata);
+}
+
+static struct temp_data *get_temp_data(struct platform_data *pdata, int cpu)
+{
+	int i;
+
+	/* cpu < 0 means get pkg temp_data */
+	if (cpu < 0)
+		return pdata->core_data[PKG_SYSFS_ATTR_NO];
+
+	for (i = BASE_SYSFS_ATTR_NO; i < MAX_CORE_DATA; i++) {
+		if (pdata->core_data[i] &&
+		    pdata->core_data[i]->cpu_core_id == topology_core_id(cpu))
+			return pdata->core_data[i];
+	}
+	return NULL;
+}
+
 static int create_core_data(struct platform_device *pdev, unsigned int cpu,
 			    int pkg_flag)
 {
@@ -499,36 +546,19 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
 	struct platform_data *pdata = platform_get_drvdata(pdev);
 	struct cpuinfo_x86 *c = &cpu_data(cpu);
 	u32 eax, edx;
-	int err, index;
+	int err;
 
 	if (!housekeeping_cpu(cpu, HK_TYPE_MISC))
 		return 0;
 
-	/*
-	 * Get the index of tdata in pdata->core_data[]
-	 * tdata for package: pdata->core_data[1]
-	 * tdata for core: pdata->core_data[2] .. pdata->core_data[NUM_REAL_CORES + 1]
-	 */
-	if (pkg_flag) {
-		index = PKG_SYSFS_ATTR_NO;
-	} else {
-		index = ida_alloc_max(&pdata->ida, NUM_REAL_CORES - 1, GFP_KERNEL);
-		if (index < 0)
-			return index;
-
-		index += BASE_SYSFS_ATTR_NO;
-	}
-
-	tdata = init_temp_data(cpu, pkg_flag);
-	if (!tdata) {
-		err = -ENOMEM;
-		goto ida_free;
-	}
+	tdata = init_temp_data(pdata, cpu, pkg_flag);
+	if (!tdata)
+		return -ENOMEM;
 
 	/* Test if we can access the status register */
 	err = rdmsr_safe_on_cpu(cpu, tdata->status_reg, &eax, &edx);
 	if (err)
-		goto exit_free;
+		goto err;
 
 	/* Make sure tdata->tjmax is a valid indicator for dynamic/static tjmax */
 	get_tjmax(tdata, &pdev->dev);
@@ -542,20 +572,15 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
 		if (get_ttarget(tdata, &pdev->dev) >= 0)
 			tdata->attr_size++;
 
-	pdata->core_data[index] = tdata;
-
 	/* Create sysfs interfaces */
 	err = create_core_attrs(tdata, pdata->hwmon_dev);
 	if (err)
-		goto exit_free;
+		goto err;
 
 	return 0;
-exit_free:
-	pdata->core_data[index] = NULL;
-	kfree(tdata);
-ida_free:
-	if (!pkg_flag)
-		ida_free(&pdata->ida, index - BASE_SYSFS_ATTR_NO);
+
+err:
+	destroy_temp_data(pdata, tdata);
 	return err;
 }
 
@@ -566,10 +591,8 @@ coretemp_add_core(struct platform_device *pdev, unsigned int cpu, int pkg_flag)
 		dev_err(&pdev->dev, "Adding Core %u failed\n", cpu);
 }
 
-static void coretemp_remove_core(struct platform_data *pdata, int indx)
+static void coretemp_remove_core(struct platform_data *pdata, struct temp_data *tdata)
 {
-	struct temp_data *tdata = pdata->core_data[indx];
-
 	/* if we errored on add then this is already gone */
 	if (!tdata)
 		return;
@@ -577,11 +600,7 @@ static void coretemp_remove_core(struct platform_data *pdata, int indx)
 	/* Remove the sysfs attributes */
 	sysfs_remove_group(&pdata->hwmon_dev->kobj, &tdata->attr_group);
 
-	kfree(pdata->core_data[indx]);
-	pdata->core_data[indx] = NULL;
-
-	if (indx >= BASE_SYSFS_ATTR_NO)
-		ida_free(&pdata->ida, indx - BASE_SYSFS_ATTR_NO);
+	destroy_temp_data(pdata, tdata);
 }
 
 static int coretemp_device_add(int zoneid)
@@ -694,7 +713,7 @@ static int coretemp_cpu_offline(unsigned int cpu)
 	struct platform_device *pdev = coretemp_get_pdev(cpu);
 	struct platform_data *pd;
 	struct temp_data *tdata;
-	int i, target;
+	int target;
 
 	/* No need to tear down any interfaces for suspend */
 	if (cpuhp_tasks_frozen)
@@ -705,16 +724,7 @@ static int coretemp_cpu_offline(unsigned int cpu)
 	if (!pd->hwmon_dev)
 		return 0;
 
-	for (i = BASE_SYSFS_ATTR_NO; i < MAX_CORE_DATA; i++) {
-		if (pd->core_data[i] && pd->core_data[i]->cpu_core_id == topology_core_id(cpu))
-			break;
-	}
-
-	/* Too many cores and this core is not populated, just return */
-	if (i == MAX_CORE_DATA)
-		return 0;
-
-	tdata = pd->core_data[i];
+	tdata = get_temp_data(pd, cpu);
 
 	cpumask_clear_cpu(cpu, &pd->cpumask);
 
@@ -725,7 +735,7 @@ static int coretemp_cpu_offline(unsigned int cpu)
 	 */
 	target = cpumask_any_and(&pd->cpumask, topology_sibling_cpumask(cpu));
 	if (target >= nr_cpu_ids) {
-		coretemp_remove_core(pd, i);
+		coretemp_remove_core(pd, tdata);
 	} else if (tdata && tdata->cpu == cpu) {
 		mutex_lock(&tdata->update_lock);
 		tdata->cpu = target;
@@ -735,10 +745,10 @@ static int coretemp_cpu_offline(unsigned int cpu)
 	/*
 	 * If all cores in this pkg are offline, remove the interface.
 	 */
-	tdata = pd->core_data[PKG_SYSFS_ATTR_NO];
+	tdata = get_temp_data(pd, -1);
 	if (cpumask_empty(&pd->cpumask)) {
 		if (tdata)
-			coretemp_remove_core(pd, PKG_SYSFS_ATTR_NO);
+			coretemp_remove_core(pd, tdata);
 		hwmon_device_unregister(pd->hwmon_dev);
 		pd->hwmon_dev = NULL;
 		return 0;