Re: [PATCH v4 19/20] arch_topology: Add support for parsing sockets in /cpu-map

From: Ionela Voinescu
Date: Mon Jun 27 2022 - 09:48:31 EST


On Tuesday 21 Jun 2022 at 20:20:33 (+0100), Sudeep Holla wrote:
> Finally let us add support for socket nodes in /cpu-map in the device
> tree. Since this may not be present in all the old platforms and even
> most of the existing platforms, we need to assume absence of the socket
> node indicates that it is a single socket system and handle appropriately.
>
> Also it is likely that most single socket systems skip to as the node
> since it is optional.
>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> ---
> drivers/base/arch_topology.c | 37 +++++++++++++++++++++++++++++++-----
> 1 file changed, 32 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
> index 75604f783bfc..ed1cb64a95aa 100644
> --- a/drivers/base/arch_topology.c
> +++ b/drivers/base/arch_topology.c
> @@ -545,8 +545,8 @@ static int __init parse_core(struct device_node *core, int package_id,
> return 0;
> }
>
> -static int __init
> -parse_cluster(struct device_node *cluster, int cluster_id, int depth)
> +static int __init parse_cluster(struct device_node *cluster, int package_id,
> + int cluster_id, int depth)
> {
> char name[20];
> bool leaf = true;
> @@ -566,7 +566,7 @@ parse_cluster(struct device_node *cluster, int cluster_id, int depth)
> c = of_get_child_by_name(cluster, name);
> if (c) {
> leaf = false;
> - ret = parse_cluster(c, i, depth + 1);
> + ret = parse_cluster(c, package_id, i, depth + 1);
> of_node_put(c);
> if (ret != 0)
> return ret;
> @@ -590,7 +590,8 @@ parse_cluster(struct device_node *cluster, int cluster_id, int depth)
> }
>
> if (leaf) {
> - ret = parse_core(c, 0, cluster_id, core_id++);
> + ret = parse_core(c, package_id, cluster_id,
> + core_id++);
> } else {
> pr_err("%pOF: Non-leaf cluster with core %s\n",
> cluster, name);
> @@ -610,6 +611,32 @@ parse_cluster(struct device_node *cluster, int cluster_id, int depth)
> return 0;
> }
>
> +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);
> + if (c) {
> + has_socket = true;
> + ret = parse_cluster(c, package_id, -1, 0);
> + of_node_put(c);
> + if (ret != 0)
> + return ret;
> + }
> + package_id++;
> + } while (c);
> +
> + if (!has_socket)
> + ret = parse_cluster(socket, 0, -1, 0);
> +
> + return ret;
> +}
> +
> static int __init parse_dt_topology(void)
> {
> struct device_node *cn, *map;
> @@ -629,7 +656,7 @@ static int __init parse_dt_topology(void)
> if (!map)
> goto out;
>
> - ret = parse_cluster(map, -1, 0);
> + ret = parse_socket(map);
> if (ret != 0)
> goto out_map;
>
> --
> 2.36.1
>

Reviewed-by: Ionela Voinescu <ionela.voinescu@xxxxxxx>

Thanks,
Ionela.