[PATCH V1] firmware: arm_scmi: Optimize the iteration of scmi_requested_devices

From: Peng Fan (OSS)
Date: Tue Jan 07 2025 - 00:20:57 EST


From: Peng Fan <peng.fan@xxxxxxx>

scmi_requested_devices is organized in IDR based link lists, so only
need to search the link lists when there is a match protocol_id.

Back to search the next id with 'continue' to save cpu cycles, if
protocol_id does not match.

Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---

V1:
Follow Dan's suggestion

drivers/firmware/arm_scmi/bus.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 157172a5f2b5..c26f470fc24f 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -72,14 +72,11 @@ static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
*/
mutex_lock(&scmi_requested_devices_mtx);
idr_for_each_entry(&scmi_requested_devices, head, id) {
- if (!phead) {
- /* A list found registered in the IDR is never empty */
- rdev = list_first_entry(head, struct scmi_requested_dev,
- node);
- if (rdev->id_table->protocol_id ==
- id_table->protocol_id)
- phead = head;
- }
+ /* A list found registered in the IDR is never empty */
+ rdev = list_first_entry(head, struct scmi_requested_dev, node);
+ if (rdev->id_table->protocol_id != id_table->protocol_id)
+ continue;
+
list_for_each_entry(rdev, head, node) {
if (!strcmp(rdev->id_table->name, id_table->name)) {
pr_err("Ignoring duplicate request [%d] %s\n",
@@ -89,6 +86,8 @@ static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
goto out;
}
}
+ phead = head;
+ break;
}

/*
--
2.37.1