Commit 880f5f58 authored by Vincenzo Mezzela's avatar Vincenzo Mezzela Committed by Greg Kroah-Hartman
Browse files

drivers: arch_topology: use __free attribute instead of of_node_put() 



Introduce the __free attribute for scope-based resource management.
Resources allocated with __free are automatically released at the end of
the scope. This enhancement aims to mitigate memory management issues
associated with forgetting to release resources by utilizing __free
instead of of_node_put().

The declaration of the device_node used within the do-while loops is
moved directly within the loop so that the resource is automatically
freed at the end of each iteration.

Acked-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Suggested-by: default avatarJulia Lawall <julia.lawall@inria.fr>
Signed-off-by: default avatarVincenzo Mezzela <vincenzo.mezzela@gmail.com>
Link: https://lore.kernel.org/r/20240607163350.392971-3-vincenzo.mezzela@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 97b19745

drivers/base/arch_topology.c

+26 −30
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


#include <linux/acpi.h>

#include <linux/cacheinfo.h>

#include <linux/cleanup.h>

#include <linux/cpu.h>

#include <linux/cpufreq.h>

#include <linux/device.h>
@@ -513,10 +514,10 @@ core_initcall(free_raw_capacity); 
 */

static int __init get_cpu_for_node(struct device_node *node)

{

	struct device_node *cpu_node;

	int cpu;

	struct device_node *cpu_node __free(device_node) =

		of_parse_phandle(node, "cpu", 0);



	cpu_node = of_parse_phandle(node, "cpu", 0);

	if (!cpu_node)

		return -1;
@@ -527,7 +528,6 @@ static int __init get_cpu_for_node(struct device_node *node) 
		pr_info("CPU node for %pOF exist but the possible cpu range is :%*pbl\n",

			cpu_node, cpumask_pr_args(cpu_possible_mask));



	of_node_put(cpu_node);

	return cpu;

}
@@ -538,11 +538,12 @@ static int __init parse_core(struct device_node *core, int package_id, 
	bool leaf = true;

	int i = 0;

	int cpu;

	struct device_node *t;



	do {

		snprintf(name, sizeof(name), "thread%d", i);

		t = of_get_child_by_name(core, name);

		struct device_node *t __free(device_node) =

			of_get_child_by_name(core, name);



		if (!t)

			break;
@@ -555,10 +556,8 @@ static int __init parse_core(struct device_node *core, int package_id, 
			cpu_topology[cpu].thread_id = i;

		} else if (cpu != -ENODEV) {

			pr_err("%pOF: Can't get CPU for thread\n", t);

			of_node_put(t);

			return -EINVAL;

		}

		of_node_put(t);

		i++;

	} while (1);
@@ -587,7 +586,6 @@ static int __init parse_cluster(struct device_node *cluster, int package_id, 
	char name[20];

	bool leaf = true;

	bool has_cores = false;

	struct device_node *c;

	int core_id = 0;

	int i, ret;
@@ -599,7 +597,9 @@ static int __init parse_cluster(struct device_node *cluster, int package_id, 
	i = 0;

	do {

		snprintf(name, sizeof(name), "cluster%d", i);

		c = of_get_child_by_name(cluster, name);

		struct device_node *c __free(device_node) =

			of_get_child_by_name(cluster, name);



		if (!c)

			break;
@@ -607,7 +607,6 @@ static int __init parse_cluster(struct device_node *cluster, int package_id, 
		ret = parse_cluster(c, package_id, i, depth + 1);

		if (depth > 0)

			pr_warn("Topology for clusters of clusters not yet supported\n");

		of_node_put(c);

		if (ret != 0)

			return ret;

		i++;
@@ -617,7 +616,9 @@ static int __init parse_cluster(struct device_node *cluster, int package_id, 
	i = 0;

	do {

		snprintf(name, sizeof(name), "core%d", i);

		c = of_get_child_by_name(cluster, name);

		struct device_node *c __free(device_node) =

			of_get_child_by_name(cluster, name);



		if (!c)

			break;
@@ -625,21 +626,19 @@ static int __init parse_cluster(struct device_node *cluster, int package_id, 


		if (depth == 0) {

			pr_err("%pOF: cpu-map children should be clusters\n", c);

			of_node_put(c);

			return -EINVAL;

		}



		if (leaf) {

			ret = parse_core(c, package_id, cluster_id, core_id++);

			if (ret != 0)

				return ret;

		} else {

			pr_err("%pOF: Non-leaf cluster with core %s\n",

			       cluster, name);

			ret = -EINVAL;

			return -EINVAL;

		}



		of_node_put(c);

		if (ret != 0)

			return ret;

		i++;

	} while (1);
@@ -652,19 +651,19 @@ static int __init parse_cluster(struct device_node *cluster, int package_id, 
static int __init parse_socket(struct device_node *socket)

{

	char name[20];

	struct device_node *c;

	bool has_socket = false;

	int package_id = 0, ret;



	do {

		snprintf(name, sizeof(name), "socket%d", package_id);

		c = of_get_child_by_name(socket, name);

		struct device_node *c __free(device_node) =

			of_get_child_by_name(socket, name);



		if (!c)

			break;



		has_socket = true;

		ret = parse_cluster(c, package_id, -1, 0);

		of_node_put(c);

		if (ret != 0)

			return ret;
@@ -679,11 +678,11 @@ static int __init parse_socket(struct device_node *socket) 


static int __init parse_dt_topology(void)

{

	struct device_node *cn, *map;

	int ret = 0;

	int cpu;

	struct device_node *cn __free(device_node) =

		of_find_node_by_path("/cpus");



	cn = of_find_node_by_path("/cpus");

	if (!cn) {

		pr_err("No CPU information found in DT\n");

		return 0;
@@ -693,13 +692,15 @@ static int __init parse_dt_topology(void) 
	 * When topology is provided cpu-map is essentially a root

	 * cluster with restricted subnodes.

	 */

	map = of_get_child_by_name(cn, "cpu-map");

	struct device_node *map __free(device_node) =

		of_get_child_by_name(cn, "cpu-map");



	if (!map)

		goto out;

		return ret;



	ret = parse_socket(map);

	if (ret != 0)

		goto out_map;

		return ret;



	topology_normalize_cpu_scale();
@@ -709,14 +710,9 @@ static int __init parse_dt_topology(void) 
	 */

	for_each_possible_cpu(cpu)

		if (cpu_topology[cpu].package_id < 0) {

			ret = -EINVAL;

			break;

			return -EINVAL;

		}



out_map:

	of_node_put(map);

out:

	of_node_put(cn);

	return ret;

}

#endif