From ee5dcedaf72d797ca0cdd472bbf85c8bd5c0d8e6 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Thu, 22 Dec 2022 18:50:48 +0000 Subject: [PATCH] firmware: arm_scmi: Introduce a new lifecycle for protocol devices Protocol devices are created or destroyed depending on the related device request/unrequest events emitted on the scmi_requested_devices_nh notification chain by the SCMI bus and served in the driver by the scmi_device_request_notifier. Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20221222185049.737625-9-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 45 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 83a43a5..115baaa 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -14,6 +14,8 @@ * Copyright (C) 2018-2021 ARM Ltd. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -140,6 +142,7 @@ struct scmi_protocol_instance { * @bus_nb: A notifier to listen for device bind/unbind on the scmi bus * @dev_req_nb: A notifier to listen for device request/unrequest on the scmi * bus + * @devreq_mtx: A mutex to serialize device creation for this SCMI instance */ struct scmi_info { struct device *dev; @@ -161,6 +164,8 @@ struct scmi_info { int users; struct notifier_block bus_nb; struct notifier_block dev_req_nb; + /* Serialize device creation process for this instance */ + struct mutex devreq_mtx; }; #define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle) @@ -255,6 +260,40 @@ void scmi_protocol_unregister(const struct scmi_protocol *proto) } EXPORT_SYMBOL_GPL(scmi_protocol_unregister); +/** + * scmi_create_protocol_devices - Create devices for all pending requests for + * this SCMI instance. + * + * @np: The device node describing the protocol + * @info: The SCMI instance descriptor + * @prot_id: The protocol ID + * @name: The optional name of the device to be created: if not provided this + * call will lead to the creation of all the devices currently requested + * for the specified protocol. + */ +static void scmi_create_protocol_devices(struct device_node *np, + struct scmi_info *info, + int prot_id, const char *name) +{ + struct scmi_device *sdev; + + mutex_lock(&info->devreq_mtx); + sdev = scmi_device_create(np, info->dev, prot_id, name); + if (name && !sdev) + dev_err(info->dev, + "failed to create device for protocol 0x%X (%s)\n", + prot_id, name); + mutex_unlock(&info->devreq_mtx); +} + +static void scmi_destroy_protocol_devices(struct scmi_info *info, + int prot_id, const char *name) +{ + mutex_lock(&info->devreq_mtx); + scmi_device_destroy(info->dev, prot_id, name); + mutex_unlock(&info->devreq_mtx); +} + void scmi_notification_instance_data_set(const struct scmi_handle *handle, void *priv) { @@ -2283,8 +2322,12 @@ static int scmi_device_request_notifier(struct notifier_block *nb, switch (action) { case SCMI_BUS_NOTIFY_DEVICE_REQUEST: + scmi_create_protocol_devices(np, info, id_table->protocol_id, + id_table->name); break; case SCMI_BUS_NOTIFY_DEVICE_UNREQUEST: + scmi_destroy_protocol_devices(info, id_table->protocol_id, + id_table->name); break; default: return NOTIFY_DONE; @@ -2318,6 +2361,7 @@ static int scmi_probe(struct platform_device *pdev) idr_init(&info->protocols); mutex_init(&info->protocols_mtx); idr_init(&info->active_protocols); + mutex_init(&info->devreq_mtx); platform_set_drvdata(pdev, info); idr_init(&info->tx_idr); @@ -2412,6 +2456,7 @@ static int scmi_probe(struct platform_device *pdev) } of_node_get(child); + scmi_create_protocol_devices(child, info, prot_id, NULL); } return 0; -- 2.7.4