From 9115c20ac1ee9e92a3e751e352db818b7f95746a Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Thu, 22 Dec 2022 18:50:43 +0000
Subject: firmware: arm_scmi: Move protocol registration helpers

Move protocol registration helpers and logic out of bus.c compilation
unit into driver.c.

No functional change.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-4-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/bus.c | 68 -----------------------------------------
 1 file changed, 68 deletions(-)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 35bb70724d44..089957f5fb9b 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -16,8 +16,6 @@
 #include "common.h"
 
 static DEFINE_IDA(scmi_bus_id);
-static DEFINE_IDR(scmi_protocols);
-static DEFINE_SPINLOCK(protocol_lock);
 
 static const struct scmi_device_id *
 scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
@@ -76,30 +74,6 @@ struct scmi_device *scmi_child_dev_find(struct device *parent,
 	return to_scmi_dev(dev);
 }
 
-const struct scmi_protocol *scmi_protocol_get(int protocol_id)
-{
-	const struct scmi_protocol *proto;
-
-	proto = idr_find(&scmi_protocols, protocol_id);
-	if (!proto || !try_module_get(proto->owner)) {
-		pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id);
-		return NULL;
-	}
-
-	pr_debug("Found SCMI Protocol 0x%x\n", protocol_id);
-
-	return proto;
-}
-
-void scmi_protocol_put(int protocol_id)
-{
-	const struct scmi_protocol *proto;
-
-	proto = idr_find(&scmi_protocols, protocol_id);
-	if (proto)
-		module_put(proto->owner);
-}
-
 static int scmi_dev_probe(struct device *dev)
 {
 	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
@@ -232,48 +206,6 @@ void scmi_set_handle(struct scmi_device *scmi_dev)
 		scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev);
 }
 
-int scmi_protocol_register(const struct scmi_protocol *proto)
-{
-	int ret;
-
-	if (!proto) {
-		pr_err("invalid protocol\n");
-		return -EINVAL;
-	}
-
-	if (!proto->instance_init) {
-		pr_err("missing init for protocol 0x%x\n", proto->id);
-		return -EINVAL;
-	}
-
-	spin_lock(&protocol_lock);
-	ret = idr_alloc(&scmi_protocols, (void *)proto,
-			proto->id, proto->id + 1, GFP_ATOMIC);
-	spin_unlock(&protocol_lock);
-	if (ret != proto->id) {
-		pr_err("unable to allocate SCMI idr slot for 0x%x - err %d\n",
-		       proto->id, ret);
-		return ret;
-	}
-
-	pr_debug("Registered SCMI Protocol 0x%x\n", proto->id);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(scmi_protocol_register);
-
-void scmi_protocol_unregister(const struct scmi_protocol *proto)
-{
-	spin_lock(&protocol_lock);
-	idr_remove(&scmi_protocols, proto->id);
-	spin_unlock(&protocol_lock);
-
-	pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id);
-
-	return;
-}
-EXPORT_SYMBOL_GPL(scmi_protocol_unregister);
-
 static int __scmi_devices_unregister(struct device *dev, void *data)
 {
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
-- 
cgit v1.2.3


From 53b8c25df7082edd78a3fc63e359abee0f28fa70 Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Thu, 22 Dec 2022 18:50:44 +0000
Subject: firmware: arm_scmi: Add common notifier helpers

Add a pair of notifier chains and generic empty notifier callbacks.
Currently they are still unused but they will be used to act properly
on device request and creation events.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-5-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/bus.c    |  6 ++-
 drivers/firmware/arm_scmi/common.h |  5 +++
 drivers/firmware/arm_scmi/driver.c | 83 +++++++++++++++++++++++++++++++++++++-
 3 files changed, 92 insertions(+), 2 deletions(-)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 089957f5fb9b..bed566f58029 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -15,6 +15,9 @@
 
 #include "common.h"
 
+BLOCKING_NOTIFIER_HEAD(scmi_requested_devices_nh);
+EXPORT_SYMBOL_GPL(scmi_requested_devices_nh);
+
 static DEFINE_IDA(scmi_bus_id);
 
 static const struct scmi_device_id *
@@ -94,12 +97,13 @@ static void scmi_dev_remove(struct device *dev)
 		scmi_drv->remove(scmi_dev);
 }
 
-static struct bus_type scmi_bus_type = {
+struct bus_type scmi_bus_type = {
 	.name =	"scmi_protocol",
 	.match = scmi_dev_match,
 	.probe = scmi_dev_probe,
 	.remove = scmi_dev_remove,
 };
+EXPORT_SYMBOL_GPL(scmi_bus_type);
 
 int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
 			 const char *mod_name)
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 6a38244494fd..7ddae90eb945 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -105,6 +105,11 @@ void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
 
 int __init scmi_bus_init(void);
 void __exit scmi_bus_exit(void);
+extern struct bus_type scmi_bus_type;
+
+#define SCMI_BUS_NOTIFY_DEVICE_REQUEST		0
+#define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST	1
+extern struct blocking_notifier_head scmi_requested_devices_nh;
 
 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index d1e32ea6d90a..62760bed1645 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -150,6 +150,9 @@ struct scmi_protocol_instance {
  * @notify_priv: Pointer to private data structure specific to notifications.
  * @node: List head
  * @users: Number of users of this 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
  */
 struct scmi_info {
 	struct device *dev;
@@ -169,9 +172,13 @@ struct scmi_info {
 	void *notify_priv;
 	struct list_head node;
 	int users;
+	struct notifier_block bus_nb;
+	struct notifier_block dev_req_nb;
 };
 
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
+#define bus_nb_to_scmi_info(nb)	container_of(nb, struct scmi_info, bus_nb)
+#define req_nb_to_scmi_info(nb)	container_of(nb, struct scmi_info, dev_req_nb)
 
 static const int scmi_linux_errmap[] = {
 	/* better than switch case as long as return value is continuous */
@@ -2509,6 +2516,60 @@ static void scmi_cleanup_txrx_channels(struct scmi_info *info)
 	scmi_cleanup_channels(info, &info->rx_idr);
 }
 
+static int scmi_bus_notifier(struct notifier_block *nb,
+			     unsigned long action, void *data)
+{
+	struct scmi_info *info = bus_nb_to_scmi_info(nb);
+	struct scmi_device *sdev = to_scmi_dev(data);
+
+	/* Skip transport devices and devices of different SCMI instances */
+	if (!strncmp(sdev->name, "__scmi_transport_device", 23) ||
+	    sdev->dev.parent != info->dev)
+		return NOTIFY_DONE;
+
+	switch (action) {
+	case BUS_NOTIFY_BIND_DRIVER:
+		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	dev_dbg(info->dev, "Device %s (%s) is now %s\n", dev_name(&sdev->dev),
+		sdev->name, action == BUS_NOTIFY_BIND_DRIVER ?
+		"about to be BOUND." : "UNBOUND.");
+
+	return NOTIFY_OK;
+}
+
+static int scmi_device_request_notifier(struct notifier_block *nb,
+					unsigned long action, void *data)
+{
+	struct device_node *np;
+	struct scmi_device_id *id_table = data;
+	struct scmi_info *info = req_nb_to_scmi_info(nb);
+
+	np = idr_find(&info->active_protocols, id_table->protocol_id);
+	if (!np)
+		return NOTIFY_DONE;
+
+	dev_dbg(info->dev, "%sRequested device (%s) for protocol 0x%x\n",
+		action == SCMI_BUS_NOTIFY_DEVICE_REQUEST ? "" : "UN-",
+		id_table->name, id_table->protocol_id);
+
+	switch (action) {
+	case SCMI_BUS_NOTIFY_DEVICE_REQUEST:
+		break;
+	case SCMI_BUS_NOTIFY_DEVICE_UNREQUEST:
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	return NOTIFY_OK;
+}
+
 static int scmi_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -2528,6 +2589,8 @@ static int scmi_probe(struct platform_device *pdev)
 
 	info->dev = dev;
 	info->desc = desc;
+	info->bus_nb.notifier_call = scmi_bus_notifier;
+	info->dev_req_nb.notifier_call = scmi_device_request_notifier;
 	INIT_LIST_HEAD(&info->node);
 	idr_init(&info->protocols);
 	mutex_init(&info->protocols_mtx);
@@ -2563,10 +2626,19 @@ static int scmi_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	ret = scmi_xfer_info_init(info);
+	ret = bus_register_notifier(&scmi_bus_type, &info->bus_nb);
 	if (ret)
 		goto clear_txrx_setup;
 
+	ret = blocking_notifier_chain_register(&scmi_requested_devices_nh,
+					       &info->dev_req_nb);
+	if (ret)
+		goto clear_bus_notifier;
+
+	ret = scmi_xfer_info_init(info);
+	if (ret)
+		goto clear_dev_req_notifier;
+
 	if (scmi_notification_init(handle))
 		dev_err(dev, "SCMI Notifications NOT available.\n");
 
@@ -2624,6 +2696,11 @@ static int scmi_probe(struct platform_device *pdev)
 
 notification_exit:
 	scmi_notification_exit(&info->handle);
+clear_dev_req_notifier:
+	blocking_notifier_chain_unregister(&scmi_requested_devices_nh,
+					   &info->dev_req_nb);
+clear_bus_notifier:
+	bus_unregister_notifier(&scmi_bus_type, &info->bus_nb);
 clear_txrx_setup:
 	scmi_cleanup_txrx_channels(info);
 	return ret;
@@ -2652,6 +2729,10 @@ static int scmi_remove(struct platform_device *pdev)
 		of_node_put(child);
 	idr_destroy(&info->active_protocols);
 
+	blocking_notifier_chain_unregister(&scmi_requested_devices_nh,
+					   &info->dev_req_nb);
+	bus_unregister_notifier(&scmi_bus_type, &info->bus_nb);
+
 	/* Safe to free channels since no more users */
 	scmi_cleanup_txrx_channels(info);
 
-- 
cgit v1.2.3


From d3cd7c525fd2ecce3a6c963f314969a54783d211 Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Thu, 22 Dec 2022 18:50:45 +0000
Subject: firmware: arm_scmi: Refactor protocol device creation

Move protocol device request helpers from driver.c compilation unit to
bus.c, so reducing the cross interactions between driver.c and bus.c.

Get rid of old protocol device creation process as a whole from driver.c
and remove also stale SCMI system power unicity checks.

While at that make such helpers call into scmi_requested_devices_nh
notification chain.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-6-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/bus.c    | 157 +++++++++++++++++++-
 drivers/firmware/arm_scmi/common.h |   2 -
 drivers/firmware/arm_scmi/driver.c | 296 -------------------------------------
 3 files changed, 156 insertions(+), 299 deletions(-)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index bed566f58029..e63cc1194d43 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -9,6 +9,7 @@
 
 #include <linux/types.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/device.h>
@@ -20,6 +21,160 @@ EXPORT_SYMBOL_GPL(scmi_requested_devices_nh);
 
 static DEFINE_IDA(scmi_bus_id);
 
+static DEFINE_IDR(scmi_requested_devices);
+/* Protect access to scmi_requested_devices */
+static DEFINE_MUTEX(scmi_requested_devices_mtx);
+
+struct scmi_requested_dev {
+	const struct scmi_device_id *id_table;
+	struct list_head node;
+};
+
+/**
+ * scmi_protocol_device_request  - Helper to request a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be created.
+ *
+ * This helper let an SCMI driver request specific devices identified by the
+ * @id_table to be created for each active SCMI instance.
+ *
+ * The requested device name MUST NOT be already existent for any protocol;
+ * at first the freshly requested @id_table is annotated in the IDR table
+ * @scmi_requested_devices and then the requested device is advertised to any
+ * registered party via the @scmi_requested_devices_nh notification chain.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
+{
+	int ret = 0;
+	unsigned int id = 0;
+	struct list_head *head, *phead = NULL;
+	struct scmi_requested_dev *rdev;
+
+	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
+
+	/*
+	 * Search for the matching protocol rdev list and then search
+	 * of any existent equally named device...fails if any duplicate found.
+	 */
+	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;
+		}
+		list_for_each_entry(rdev, head, node) {
+			if (!strcmp(rdev->id_table->name, id_table->name)) {
+				pr_err("Ignoring duplicate request [%d] %s\n",
+				       rdev->id_table->protocol_id,
+				       rdev->id_table->name);
+				ret = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	/*
+	 * No duplicate found for requested id_table, so let's create a new
+	 * requested device entry for this new valid request.
+	 */
+	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
+	if (!rdev) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	rdev->id_table = id_table;
+
+	/*
+	 * Append the new requested device table descriptor to the head of the
+	 * related protocol list, eventually creating such head if not already
+	 * there.
+	 */
+	if (!phead) {
+		phead = kzalloc(sizeof(*phead), GFP_KERNEL);
+		if (!phead) {
+			kfree(rdev);
+			ret = -ENOMEM;
+			goto out;
+		}
+		INIT_LIST_HEAD(phead);
+
+		ret = idr_alloc(&scmi_requested_devices, (void *)phead,
+				id_table->protocol_id,
+				id_table->protocol_id + 1, GFP_KERNEL);
+		if (ret != id_table->protocol_id) {
+			pr_err("Failed to save SCMI device - ret:%d\n", ret);
+			kfree(rdev);
+			kfree(phead);
+			ret = -EINVAL;
+			goto out;
+		}
+		ret = 0;
+	}
+	list_add(&rdev->node, phead);
+
+out:
+	mutex_unlock(&scmi_requested_devices_mtx);
+
+	if (!ret)
+		blocking_notifier_call_chain(&scmi_requested_devices_nh,
+					     SCMI_BUS_NOTIFY_DEVICE_REQUEST,
+					     (void *)rdev->id_table);
+
+	return ret;
+}
+
+/**
+ * scmi_protocol_device_unrequest  - Helper to unrequest a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be unrequested.
+ *
+ * The unrequested device, described by the provided id_table, is at first
+ * removed from the IDR @scmi_requested_devices and then the removal is
+ * advertised to any registered party via the @scmi_requested_devices_nh
+ * notification chain.
+ */
+static void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table)
+{
+	struct list_head *phead;
+
+	pr_debug("Unrequesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
+
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+	if (phead) {
+		struct scmi_requested_dev *victim, *tmp;
+
+		list_for_each_entry_safe(victim, tmp, phead, node) {
+			if (!strcmp(victim->id_table->name, id_table->name)) {
+				list_del(&victim->node);
+
+				mutex_unlock(&scmi_requested_devices_mtx);
+				blocking_notifier_call_chain(&scmi_requested_devices_nh,
+							     SCMI_BUS_NOTIFY_DEVICE_UNREQUEST,
+							     (void *)victim->id_table);
+				kfree(victim);
+				mutex_lock(&scmi_requested_devices_mtx);
+				break;
+			}
+		}
+
+		if (list_empty(phead)) {
+			idr_remove(&scmi_requested_devices,
+				   id_table->protocol_id);
+			kfree(phead);
+		}
+	}
+	mutex_unlock(&scmi_requested_devices_mtx);
+}
+
 static const struct scmi_device_id *
 scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
 {
@@ -124,7 +279,7 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
 
 	retval = driver_register(&driver->driver);
 	if (!retval)
-		pr_debug("registered new scmi driver %s\n", driver->name);
+		pr_debug("Registered new scmi driver %s\n", driver->name);
 
 	return retval;
 }
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 7ddae90eb945..0f411679df7e 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -172,8 +172,6 @@ struct scmi_transport_ops {
 	bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
 };
 
-int scmi_protocol_device_request(const struct scmi_device_id *id_table);
-void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table);
 struct scmi_device *scmi_child_dev_find(struct device *parent,
 					int prot_id, const char *name);
 
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 62760bed1645..73f640e9448f 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -61,19 +61,6 @@ static DEFINE_MUTEX(scmi_list_mutex);
 /* Track the unique id for the transfers for debug & profiling purpose */
 static atomic_t transfer_last_id;
 
-static DEFINE_IDR(scmi_requested_devices);
-static DEFINE_MUTEX(scmi_requested_devices_mtx);
-
-/* Track globally the creation of SCMI SystemPower related devices */
-static bool scmi_syspower_registered;
-/* Protect access to scmi_syspower_registered */
-static DEFINE_MUTEX(scmi_syspower_mtx);
-
-struct scmi_requested_dev {
-	const struct scmi_device_id *id_table;
-	struct list_head node;
-};
-
 /**
  * struct scmi_xfers_info - Structure to manage transfer information
  *
@@ -2199,288 +2186,6 @@ static int scmi_channels_setup(struct scmi_info *info)
 	return 0;
 }
 
-/**
- * scmi_get_protocol_device  - Helper to get/create an SCMI device.
- *
- * @np: A device node representing a valid active protocols for the referred
- * SCMI instance.
- * @info: The referred SCMI instance for which we are getting/creating this
- * device.
- * @prot_id: The protocol ID.
- * @name: The device name.
- *
- * Referring to the specific SCMI instance identified by @info, this helper
- * takes care to return a properly initialized device matching the requested
- * @proto_id and @name: if device was still not existent it is created as a
- * child of the specified SCMI instance @info and its transport properly
- * initialized as usual.
- *
- * Return: A properly initialized scmi device, NULL otherwise.
- */
-static inline struct scmi_device *
-scmi_get_protocol_device(struct device_node *np, struct scmi_info *info,
-			 int prot_id, const char *name)
-{
-	struct scmi_device *sdev;
-
-	/* Already created for this parent SCMI instance ? */
-	sdev = scmi_child_dev_find(info->dev, prot_id, name);
-	if (sdev)
-		return sdev;
-
-	mutex_lock(&scmi_syspower_mtx);
-	if (prot_id == SCMI_PROTOCOL_SYSTEM && scmi_syspower_registered) {
-		dev_warn(info->dev,
-			 "SCMI SystemPower protocol device must be unique !\n");
-		mutex_unlock(&scmi_syspower_mtx);
-
-		return NULL;
-	}
-
-	pr_debug("Creating SCMI device (%s) for protocol %x\n", name, prot_id);
-
-	sdev = scmi_device_create(np, info->dev, prot_id, name);
-	if (!sdev) {
-		dev_err(info->dev, "failed to create %d protocol device\n",
-			prot_id);
-		mutex_unlock(&scmi_syspower_mtx);
-
-		return NULL;
-	}
-
-	if (prot_id == SCMI_PROTOCOL_SYSTEM)
-		scmi_syspower_registered = true;
-
-	mutex_unlock(&scmi_syspower_mtx);
-
-	return sdev;
-}
-
-static inline void
-scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
-			    int prot_id, const char *name)
-{
-	struct scmi_device *sdev;
-
-	sdev = scmi_get_protocol_device(np, info, prot_id, name);
-	if (!sdev)
-		return;
-
-	/* setup handle now as the transport is ready */
-	scmi_set_handle(sdev);
-}
-
-/**
- * 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
- *
- * All devices previously requested for this instance (if any) are found and
- * created by scanning the proper @&scmi_requested_devices entry.
- */
-static void scmi_create_protocol_devices(struct device_node *np,
-					 struct scmi_info *info, int prot_id)
-{
-	struct list_head *phead;
-
-	mutex_lock(&scmi_requested_devices_mtx);
-	phead = idr_find(&scmi_requested_devices, prot_id);
-	if (phead) {
-		struct scmi_requested_dev *rdev;
-
-		list_for_each_entry(rdev, phead, node)
-			scmi_create_protocol_device(np, info, prot_id,
-						    rdev->id_table->name);
-	}
-	mutex_unlock(&scmi_requested_devices_mtx);
-}
-
-/**
- * scmi_protocol_device_request  - Helper to request a device
- *
- * @id_table: A protocol/name pair descriptor for the device to be created.
- *
- * This helper let an SCMI driver request specific devices identified by the
- * @id_table to be created for each active SCMI instance.
- *
- * The requested device name MUST NOT be already existent for any protocol;
- * at first the freshly requested @id_table is annotated in the IDR table
- * @scmi_requested_devices, then a matching device is created for each already
- * active SCMI instance. (if any)
- *
- * This way the requested device is created straight-away for all the already
- * initialized(probed) SCMI instances (handles) and it remains also annotated
- * as pending creation if the requesting SCMI driver was loaded before some
- * SCMI instance and related transports were available: when such late instance
- * is probed, its probe will take care to scan the list of pending requested
- * devices and create those on its own (see @scmi_create_protocol_devices and
- * its enclosing loop)
- *
- * Return: 0 on Success
- */
-int scmi_protocol_device_request(const struct scmi_device_id *id_table)
-{
-	int ret = 0;
-	unsigned int id = 0;
-	struct list_head *head, *phead = NULL;
-	struct scmi_requested_dev *rdev;
-	struct scmi_info *info;
-
-	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
-		 id_table->name, id_table->protocol_id);
-
-	/*
-	 * Search for the matching protocol rdev list and then search
-	 * of any existent equally named device...fails if any duplicate found.
-	 */
-	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;
-		}
-		list_for_each_entry(rdev, head, node) {
-			if (!strcmp(rdev->id_table->name, id_table->name)) {
-				pr_err("Ignoring duplicate request [%d] %s\n",
-				       rdev->id_table->protocol_id,
-				       rdev->id_table->name);
-				ret = -EINVAL;
-				goto out;
-			}
-		}
-	}
-
-	/*
-	 * No duplicate found for requested id_table, so let's create a new
-	 * requested device entry for this new valid request.
-	 */
-	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
-	if (!rdev) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	rdev->id_table = id_table;
-
-	/*
-	 * Append the new requested device table descriptor to the head of the
-	 * related protocol list, eventually creating such head if not already
-	 * there.
-	 */
-	if (!phead) {
-		phead = kzalloc(sizeof(*phead), GFP_KERNEL);
-		if (!phead) {
-			kfree(rdev);
-			ret = -ENOMEM;
-			goto out;
-		}
-		INIT_LIST_HEAD(phead);
-
-		ret = idr_alloc(&scmi_requested_devices, (void *)phead,
-				id_table->protocol_id,
-				id_table->protocol_id + 1, GFP_KERNEL);
-		if (ret != id_table->protocol_id) {
-			pr_err("Failed to save SCMI device - ret:%d\n", ret);
-			kfree(rdev);
-			kfree(phead);
-			ret = -EINVAL;
-			goto out;
-		}
-		ret = 0;
-	}
-	list_add(&rdev->node, phead);
-
-	/*
-	 * Now effectively create and initialize the requested device for every
-	 * already initialized SCMI instance which has registered the requested
-	 * protocol as a valid active one: i.e. defined in DT and supported by
-	 * current platform FW.
-	 */
-	mutex_lock(&scmi_list_mutex);
-	list_for_each_entry(info, &scmi_list, node) {
-		struct device_node *child;
-
-		child = idr_find(&info->active_protocols,
-				 id_table->protocol_id);
-		if (child) {
-			struct scmi_device *sdev;
-
-			sdev = scmi_get_protocol_device(child, info,
-							id_table->protocol_id,
-							id_table->name);
-			if (sdev) {
-				/* Set handle if not already set: device existed */
-				if (!sdev->handle)
-					sdev->handle =
-						scmi_handle_get_from_info_unlocked(info);
-				/* Relink consumer and suppliers */
-				if (sdev->handle)
-					scmi_device_link_add(&sdev->dev,
-							     sdev->handle->dev);
-			}
-		} else {
-			dev_err(info->dev,
-				"Failed. SCMI protocol %d not active.\n",
-				id_table->protocol_id);
-		}
-	}
-	mutex_unlock(&scmi_list_mutex);
-
-out:
-	mutex_unlock(&scmi_requested_devices_mtx);
-
-	return ret;
-}
-
-/**
- * scmi_protocol_device_unrequest  - Helper to unrequest a device
- *
- * @id_table: A protocol/name pair descriptor for the device to be unrequested.
- *
- * An helper to let an SCMI driver release its request about devices; note that
- * devices are created and initialized once the first SCMI driver request them
- * but they destroyed only on SCMI core unloading/unbinding.
- *
- * The current SCMI transport layer uses such devices as internal references and
- * as such they could be shared as same transport between multiple drivers so
- * that cannot be safely destroyed till the whole SCMI stack is removed.
- * (unless adding further burden of refcounting.)
- */
-void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table)
-{
-	struct list_head *phead;
-
-	pr_debug("Unrequesting SCMI device (%s) for protocol %x\n",
-		 id_table->name, id_table->protocol_id);
-
-	mutex_lock(&scmi_requested_devices_mtx);
-	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
-	if (phead) {
-		struct scmi_requested_dev *victim, *tmp;
-
-		list_for_each_entry_safe(victim, tmp, phead, node) {
-			if (!strcmp(victim->id_table->name, id_table->name)) {
-				list_del(&victim->node);
-				kfree(victim);
-				break;
-			}
-		}
-
-		if (list_empty(phead)) {
-			idr_remove(&scmi_requested_devices,
-				   id_table->protocol_id);
-			kfree(phead);
-		}
-	}
-	mutex_unlock(&scmi_requested_devices_mtx);
-}
-
 static int scmi_chan_destroy(int id, void *p, void *idr)
 {
 	struct scmi_chan_info *cinfo = p;
@@ -2689,7 +2394,6 @@ static int scmi_probe(struct platform_device *pdev)
 		}
 
 		of_node_get(child);
-		scmi_create_protocol_devices(child, info, prot_id);
 	}
 
 	return 0;
-- 
cgit v1.2.3


From 971fc0665f1361f23251e4d85fac4aed1b683505 Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Thu, 22 Dec 2022 18:50:46 +0000
Subject: firmware: arm_scmi: Move handle get/set helpers

Move handle get/set helpers definitions into driver.c and invoke them
through the bus notifier helper.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-7-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/bus.c    | 17 -----------------
 drivers/firmware/arm_scmi/common.h |  4 ----
 drivers/firmware/arm_scmi/driver.c | 35 +++++++++++++++++++++++++----------
 3 files changed, 25 insertions(+), 31 deletions(-)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index e63cc1194d43..61113def5a9a 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -344,27 +344,10 @@ put_dev:
 void scmi_device_destroy(struct scmi_device *scmi_dev)
 {
 	kfree_const(scmi_dev->name);
-	scmi_handle_put(scmi_dev->handle);
 	ida_free(&scmi_bus_id, scmi_dev->id);
 	device_unregister(&scmi_dev->dev);
 }
 
-void scmi_device_link_add(struct device *consumer, struct device *supplier)
-{
-	struct device_link *link;
-
-	link = device_link_add(consumer, supplier, DL_FLAG_AUTOREMOVE_CONSUMER);
-
-	WARN_ON(!link);
-}
-
-void scmi_set_handle(struct scmi_device *scmi_dev)
-{
-	scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
-	if (scmi_dev->handle)
-		scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev);
-}
-
 static int __scmi_devices_unregister(struct device *dev, void *data)
 {
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 0f411679df7e..07d34954c060 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -96,10 +96,6 @@ static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
 
 struct scmi_revision_info *
 scmi_revision_area_get(const struct scmi_protocol_handle *ph);
-int scmi_handle_put(const struct scmi_handle *handle);
-void scmi_device_link_add(struct device *consumer, struct device *supplier);
-struct scmi_handle *scmi_handle_get(struct device *dev);
-void scmi_set_handle(struct scmi_device *scmi_dev);
 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
 				     u8 *prot_imp);
 
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 73f640e9448f..8591b2c740c6 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1890,13 +1890,6 @@ static bool scmi_is_transport_atomic(const struct scmi_handle *handle,
 	return ret;
 }
 
-static inline
-struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info)
-{
-	info->users++;
-	return &info->handle;
-}
-
 /**
  * scmi_handle_get() - Get the SCMI handle for a device
  *
@@ -1908,7 +1901,7 @@ struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info)
  *
  * Return: pointer to handle if successful, NULL on error
  */
-struct scmi_handle *scmi_handle_get(struct device *dev)
+static struct scmi_handle *scmi_handle_get(struct device *dev)
 {
 	struct list_head *p;
 	struct scmi_info *info;
@@ -1918,7 +1911,8 @@ struct scmi_handle *scmi_handle_get(struct device *dev)
 	list_for_each(p, &scmi_list) {
 		info = list_entry(p, struct scmi_info, node);
 		if (dev->parent == info->dev) {
-			handle = scmi_handle_get_from_info_unlocked(info);
+			info->users++;
+			handle = &info->handle;
 			break;
 		}
 	}
@@ -1939,7 +1933,7 @@ struct scmi_handle *scmi_handle_get(struct device *dev)
  * Return: 0 is successfully released
  *	if null was passed, it returns -EINVAL;
  */
-int scmi_handle_put(const struct scmi_handle *handle)
+static int scmi_handle_put(const struct scmi_handle *handle)
 {
 	struct scmi_info *info;
 
@@ -1955,6 +1949,23 @@ int scmi_handle_put(const struct scmi_handle *handle)
 	return 0;
 }
 
+static void scmi_device_link_add(struct device *consumer,
+				 struct device *supplier)
+{
+	struct device_link *link;
+
+	link = device_link_add(consumer, supplier, DL_FLAG_AUTOREMOVE_CONSUMER);
+
+	WARN_ON(!link);
+}
+
+static void scmi_set_handle(struct scmi_device *scmi_dev)
+{
+	scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
+	if (scmi_dev->handle)
+		scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev);
+}
+
 static int __scmi_xfer_info_init(struct scmi_info *sinfo,
 				 struct scmi_xfers_info *info)
 {
@@ -2234,8 +2245,12 @@ static int scmi_bus_notifier(struct notifier_block *nb,
 
 	switch (action) {
 	case BUS_NOTIFY_BIND_DRIVER:
+		/* setup handle now as the transport is ready */
+		scmi_set_handle(sdev);
 		break;
 	case BUS_NOTIFY_UNBOUND_DRIVER:
+		scmi_handle_put(sdev->handle);
+		sdev->handle = NULL;
 		break;
 	default:
 		return NOTIFY_DONE;
-- 
cgit v1.2.3


From 2c3e674465e73e2f7eb52c39dc5c5e97e78e68ea Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Thu, 22 Dec 2022 18:50:47 +0000
Subject: firmware: arm_scmi: Refactor device create/destroy helpers

Refactor SCMI device create/destroy helpers: it is now possible to ask
for the creation of all the currently requested devices for a whole
protocol, not only for the creation of a single well-defined device.

While at that, re-instate uniqueness checks on the creation of SCMI
SystemPower devices.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-8-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/bus.c    | 141 ++++++++++++++++++++++++++++++++++---
 drivers/firmware/arm_scmi/common.h |   8 ++-
 drivers/firmware/arm_scmi/driver.c |   9 ++-
 include/linux/scmi_protocol.h      |   5 --
 4 files changed, 141 insertions(+), 22 deletions(-)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 61113def5a9a..190999a658b2 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/atomic.h>
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -30,6 +31,9 @@ struct scmi_requested_dev {
 	struct list_head node;
 };
 
+/* Track globally the creation of SCMI SystemPower related devices */
+static atomic_t scmi_syspower_registered = ATOMIC_INIT(0);
+
 /**
  * scmi_protocol_device_request  - Helper to request a device
  *
@@ -213,11 +217,11 @@ static int scmi_match_by_id_table(struct device *dev, void *data)
 	struct scmi_device_id *id_table = data;
 
 	return sdev->protocol_id == id_table->protocol_id &&
-		!strcmp(sdev->name, id_table->name);
+		(id_table->name && !strcmp(sdev->name, id_table->name));
 }
 
-struct scmi_device *scmi_child_dev_find(struct device *parent,
-					int prot_id, const char *name)
+static struct scmi_device *scmi_child_dev_find(struct device *parent,
+					       int prot_id, const char *name)
 {
 	struct scmi_device_id id_table;
 	struct device *dev;
@@ -297,13 +301,53 @@ static void scmi_device_release(struct device *dev)
 	kfree(to_scmi_dev(dev));
 }
 
-struct scmi_device *
-scmi_device_create(struct device_node *np, struct device *parent, int protocol,
-		   const char *name)
+static void __scmi_device_destroy(struct scmi_device *scmi_dev)
+{
+	pr_debug("(%s) Destroying SCMI device '%s' for protocol 0x%x (%s)\n",
+		 of_node_full_name(scmi_dev->dev.parent->of_node),
+		 dev_name(&scmi_dev->dev), scmi_dev->protocol_id,
+		 scmi_dev->name);
+
+	if (scmi_dev->protocol_id == SCMI_PROTOCOL_SYSTEM)
+		atomic_set(&scmi_syspower_registered, 0);
+
+	kfree_const(scmi_dev->name);
+	ida_free(&scmi_bus_id, scmi_dev->id);
+	device_unregister(&scmi_dev->dev);
+}
+
+static struct scmi_device *
+__scmi_device_create(struct device_node *np, struct device *parent,
+		     int protocol, const char *name)
 {
 	int id, retval;
 	struct scmi_device *scmi_dev;
 
+	/*
+	 * If the same protocol/name device already exist under the same parent
+	 * (i.e. SCMI instance) just return the existent device.
+	 * This avoids any race between the SCMI driver, creating devices for
+	 * each DT defined protocol at probe time, and the concurrent
+	 * registration of SCMI drivers.
+	 */
+	scmi_dev = scmi_child_dev_find(parent, protocol, name);
+	if (scmi_dev)
+		return scmi_dev;
+
+	/*
+	 * Ignore any possible subsequent failures while creating the device
+	 * since we are doomed anyway at that point; not using a mutex which
+	 * spans across this whole function to keep things simple and to avoid
+	 * to serialize all the __scmi_device_create calls across possibly
+	 * different SCMI server instances (parent)
+	 */
+	if (protocol == SCMI_PROTOCOL_SYSTEM &&
+	    atomic_cmpxchg(&scmi_syspower_registered, 0, 1)) {
+		dev_warn(parent,
+			 "SCMI SystemPower protocol device must be unique !\n");
+		return NULL;
+	}
+
 	scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL);
 	if (!scmi_dev)
 		return NULL;
@@ -333,6 +377,10 @@ scmi_device_create(struct device_node *np, struct device *parent, int protocol,
 	if (retval)
 		goto put_dev;
 
+	pr_debug("(%s) Created SCMI device '%s' for protocol 0x%x (%s)\n",
+		 of_node_full_name(parent->of_node),
+		 dev_name(&scmi_dev->dev), protocol, name);
+
 	return scmi_dev;
 put_dev:
 	kfree_const(scmi_dev->name);
@@ -341,18 +389,85 @@ put_dev:
 	return NULL;
 }
 
-void scmi_device_destroy(struct scmi_device *scmi_dev)
+/**
+ * scmi_device_create  - A method to create one or more SCMI devices
+ *
+ * @np: A reference to the device node to use for the new device(s)
+ * @parent: The parent device to use identifying a specific SCMI instance
+ * @protocol: The SCMI protocol to be associated with this device
+ * @name: The requested-name of the device to be created; this is optional
+ *	  and if no @name is provided, all the devices currently known to
+ *	  be requested on the SCMI bus for @protocol will be created.
+ *
+ * This method can be invoked to create a single well-defined device (like
+ * a transport device or a device requested by an SCMI driver loaded after
+ * the core SCMI stack has been probed), or to create all the devices currently
+ * known to have been requested by the loaded SCMI drivers for a specific
+ * protocol (typically during SCMI core protocol enumeration at probe time).
+ *
+ * Return: The created device (or one of them if @name was NOT provided and
+ *	   multiple devices were created) or NULL if no device was created;
+ *	   note that NULL indicates an error ONLY in case a specific @name
+ *	   was provided: when @name param was not provided, a number of devices
+ *	   could have been potentially created for a whole protocol, unless no
+ *	   device was found to have been requested for that specific protocol.
+ */
+struct scmi_device *scmi_device_create(struct device_node *np,
+				       struct device *parent, int protocol,
+				       const char *name)
 {
-	kfree_const(scmi_dev->name);
-	ida_free(&scmi_bus_id, scmi_dev->id);
-	device_unregister(&scmi_dev->dev);
+	struct list_head *phead;
+	struct scmi_requested_dev *rdev;
+	struct scmi_device *scmi_dev = NULL;
+
+	if (name)
+		return __scmi_device_create(np, parent, protocol, name);
+
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, protocol);
+	/* Nothing to do. */
+	if (!phead) {
+		mutex_unlock(&scmi_requested_devices_mtx);
+		return scmi_dev;
+	}
+
+	/* Walk the list of requested devices for protocol and create them */
+	list_for_each_entry(rdev, phead, node) {
+		struct scmi_device *sdev;
+
+		sdev = __scmi_device_create(np, parent,
+					    rdev->id_table->protocol_id,
+					    rdev->id_table->name);
+		/* Report errors and carry on... */
+		if (sdev)
+			scmi_dev = sdev;
+		else
+			pr_err("(%s) Failed to create device for protocol 0x%x (%s)\n",
+			       of_node_full_name(parent->of_node),
+			       rdev->id_table->protocol_id,
+			       rdev->id_table->name);
+	}
+	mutex_unlock(&scmi_requested_devices_mtx);
+
+	return scmi_dev;
 }
+EXPORT_SYMBOL_GPL(scmi_device_create);
+
+void scmi_device_destroy(struct device *parent, int protocol, const char *name)
+{
+	struct scmi_device *scmi_dev;
+
+	scmi_dev = scmi_child_dev_find(parent, protocol, name);
+	if (scmi_dev)
+		__scmi_device_destroy(scmi_dev);
+}
+EXPORT_SYMBOL_GPL(scmi_device_destroy);
 
 static int __scmi_devices_unregister(struct device *dev, void *data)
 {
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 
-	scmi_device_destroy(scmi_dev);
+	__scmi_device_destroy(scmi_dev);
 	return 0;
 }
 
@@ -374,6 +489,10 @@ int __init scmi_bus_init(void)
 
 void __exit scmi_bus_exit(void)
 {
+	/*
+	 * Destroy all remaining devices: just in case the drivers were
+	 * manually unbound and at first and then the modules unloaded.
+	 */
 	scmi_devices_unregister();
 	bus_unregister(&scmi_bus_type);
 	ida_destroy(&scmi_bus_id);
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 07d34954c060..19726a037991 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -107,6 +107,11 @@ extern struct bus_type scmi_bus_type;
 #define SCMI_BUS_NOTIFY_DEVICE_UNREQUEST	1
 extern struct blocking_notifier_head scmi_requested_devices_nh;
 
+struct scmi_device *scmi_device_create(struct device_node *np,
+				       struct device *parent, int protocol,
+				       const char *name);
+void scmi_device_destroy(struct device *parent, int protocol, const char *name);
+
 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
 
@@ -168,9 +173,6 @@ struct scmi_transport_ops {
 	bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
 };
 
-struct scmi_device *scmi_child_dev_find(struct device *parent,
-					int prot_id, const char *name);
-
 /**
  * struct scmi_desc - Description of SoC integration
  *
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 8591b2c740c6..83a43a5f7bb4 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2091,6 +2091,8 @@ static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
 	/* Create a uniquely named, dedicated transport device for this chan */
 	tdev = scmi_device_create(of_node, info->dev, prot_id, name);
 	if (!tdev) {
+		dev_err(info->dev,
+			"failed to create transport device (%s)\n", name);
 		devm_kfree(info->dev, cinfo);
 		return -EINVAL;
 	}
@@ -2100,7 +2102,7 @@ static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
 	ret = info->desc->ops->chan_setup(cinfo, info->dev, tx);
 	if (ret) {
 		of_node_put(of_node);
-		scmi_device_destroy(tdev);
+		scmi_device_destroy(info->dev, prot_id, name);
 		devm_kfree(info->dev, cinfo);
 		return ret;
 	}
@@ -2123,7 +2125,7 @@ idr_alloc:
 		/* Destroy channel and device only if created by this call. */
 		if (tdev) {
 			of_node_put(of_node);
-			scmi_device_destroy(tdev);
+			scmi_device_destroy(info->dev, prot_id, name);
 			devm_kfree(info->dev, cinfo);
 		}
 		return ret;
@@ -2202,10 +2204,11 @@ static int scmi_chan_destroy(int id, void *p, void *idr)
 	struct scmi_chan_info *cinfo = p;
 
 	if (cinfo->dev) {
+		struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
 		struct scmi_device *sdev = to_scmi_dev(cinfo->dev);
 
 		of_node_put(cinfo->dev->of_node);
-		scmi_device_destroy(sdev);
+		scmi_device_destroy(info->dev, id, sdev->name);
 		cinfo->dev = NULL;
 	}
 
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 4f765bc788ff..0ce5746a4470 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -804,11 +804,6 @@ struct scmi_device {
 
 #define to_scmi_dev(d) container_of(d, struct scmi_device, dev)
 
-struct scmi_device *
-scmi_device_create(struct device_node *np, struct device *parent, int protocol,
-		   const char *name);
-void scmi_device_destroy(struct scmi_device *scmi_dev);
-
 struct scmi_device_id {
 	u8 protocol_id;
 	const char *name;
-- 
cgit v1.2.3


From 37b5be82803270626286215b5bc4427ed2a3aecb Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Thu, 22 Dec 2022 18:50:49 +0000
Subject: firmware: arm_scmi: Split bus and driver into distinct modules

Make the SCMI bus on its own as a distinct module initialized at
subsys_initcall level when builtin.

Keep the SCMI driver core stack, together with any configured transport,
in a different module initialized as module_init level.

SCMI drivers initialization remain unchanged at module_init level.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221222185049.737625-10-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/Makefile |  8 ++++++--
 drivers/firmware/arm_scmi/bus.c    | 15 ++++++++++++---
 drivers/firmware/arm_scmi/common.h |  2 --
 drivers/firmware/arm_scmi/driver.c |  6 +-----
 4 files changed, 19 insertions(+), 12 deletions(-)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 9ea86f8cc8f7..f0596c386c62 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 scmi-bus-y = bus.o
+scmi-core-objs := $(scmi-bus-y)
+
 scmi-driver-y = driver.o notify.o
 scmi-transport-$(CONFIG_ARM_SCMI_HAVE_SHMEM) = shmem.o
 scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_MAILBOX) += mailbox.o
@@ -8,9 +10,11 @@ scmi-transport-$(CONFIG_ARM_SCMI_HAVE_MSG) += msg.o
 scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_VIRTIO) += virtio.o
 scmi-transport-$(CONFIG_ARM_SCMI_TRANSPORT_OPTEE) += optee.o
 scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o powercap.o
-scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \
-		    $(scmi-transport-y)
+scmi-module-objs := $(scmi-driver-y) $(scmi-protocols-y) $(scmi-transport-y)
+
+obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-core.o
 obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.o
+
 obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o
 obj-$(CONFIG_ARM_SCMI_POWER_CONTROL) += scmi_power_control.o
 
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 190999a658b2..6228f1581fe3 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -476,18 +476,21 @@ static void scmi_devices_unregister(void)
 	bus_for_each_dev(&scmi_bus_type, NULL, NULL, __scmi_devices_unregister);
 }
 
-int __init scmi_bus_init(void)
+static int __init scmi_bus_init(void)
 {
 	int retval;
 
 	retval = bus_register(&scmi_bus_type);
 	if (retval)
-		pr_err("scmi protocol bus register failed (%d)\n", retval);
+		pr_err("SCMI protocol bus register failed (%d)\n", retval);
+
+	pr_info("SCMI protocol bus registered\n");
 
 	return retval;
 }
+subsys_initcall(scmi_bus_init);
 
-void __exit scmi_bus_exit(void)
+static void __exit scmi_bus_exit(void)
 {
 	/*
 	 * Destroy all remaining devices: just in case the drivers were
@@ -497,3 +500,9 @@ void __exit scmi_bus_exit(void)
 	bus_unregister(&scmi_bus_type);
 	ida_destroy(&scmi_bus_id);
 }
+module_exit(scmi_bus_exit);
+
+MODULE_ALIAS("scmi-core");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI protocol bus");
+MODULE_LICENSE("GPL");
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 19726a037991..80f63fc8ca14 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -99,8 +99,6 @@ scmi_revision_area_get(const struct scmi_protocol_handle *ph);
 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
 				     u8 *prot_imp);
 
-int __init scmi_bus_init(void);
-void __exit scmi_bus_exit(void);
 extern struct bus_type scmi_bus_type;
 
 #define SCMI_BUS_NOTIFY_DEVICE_REQUEST		0
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 115baaa4aca9..50267eef10fa 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2638,8 +2638,6 @@ static int __init scmi_driver_init(void)
 	if (WARN_ON(!IS_ENABLED(CONFIG_ARM_SCMI_HAVE_TRANSPORT)))
 		return -EINVAL;
 
-	scmi_bus_init();
-
 	/* Initialize any compiled-in transport which provided an init/exit */
 	ret = scmi_transports_init();
 	if (ret)
@@ -2658,7 +2656,7 @@ static int __init scmi_driver_init(void)
 
 	return platform_driver_register(&scmi_driver);
 }
-subsys_initcall(scmi_driver_init);
+module_init(scmi_driver_init);
 
 static void __exit scmi_driver_exit(void)
 {
@@ -2673,8 +2671,6 @@ static void __exit scmi_driver_exit(void)
 	scmi_system_unregister();
 	scmi_powercap_unregister();
 
-	scmi_bus_exit();
-
 	scmi_transports_exit();
 
 	platform_driver_unregister(&scmi_driver);
-- 
cgit v1.2.3


From ba80acb0dfca87e6a6257932414350da85dde48f Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Wed, 18 Jan 2023 12:14:23 +0000
Subject: firmware: arm_scmi: Reject SCMI drivers when configured in raw mode

Reject SCMI driver registration when SCMI raw mode support is configured,
so as to avoid interferences between the SCMI raw mode transactions and the
normal SCMI stack operations.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-15-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/bus.c | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 6228f1581fe3..8601d75f5b9b 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -59,6 +59,12 @@ static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
 		 id_table->name, id_table->protocol_id);
 
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+		pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
+			id_table->name, id_table->protocol_id);
+		return -EINVAL;
+	}
+
 	/*
 	 * Search for the matching protocol rdev list and then search
 	 * of any existent equally named device...fails if any duplicate found.
-- 
cgit v1.2.3


From 9c54633e4e3d004c416ad680d6b0f73c2ac6f018 Mon Sep 17 00:00:00 2001
From: Cristian Marussi <cristian.marussi@arm.com>
Date: Wed, 18 Jan 2023 12:14:25 +0000
Subject: firmware: arm_scmi: Add the raw mode co-existence support

When the raw support is enabled and configured in co-existence mode the
normal SCMI drivers are allowed to register with the SCMI core and
operate as usual alongside the raw operations.

SCMI normal and raw messages will be kept segregated from each other,
but only at the transaction level. Any further possible interference at
the protocol layer will have instead to be handled by the user to attain
reliable results while using the raw transactions.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-17-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/arm_scmi/Kconfig    | 10 ++++++++++
 drivers/firmware/arm_scmi/bus.c      |  3 ++-
 drivers/firmware/arm_scmi/driver.c   | 16 ++++++++++++----
 drivers/firmware/arm_scmi/raw_mode.c |  5 ++++-
 4 files changed, 28 insertions(+), 6 deletions(-)

(limited to 'drivers/firmware/arm_scmi/bus.c')

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index 3b4f9e92b1e3..ea0f5083ac47 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -45,6 +45,16 @@ config ARM_SCMI_RAW_MODE_SUPPORT
 	  order to avoid unexpected interactions with the SCMI Raw message
 	  flow. If unsure say N.
 
+config ARM_SCMI_RAW_MODE_SUPPORT_COEX
+	bool "Allow SCMI Raw mode coexistence with normal SCMI stack"
+	depends on ARM_SCMI_RAW_MODE_SUPPORT
+	help
+	  Allow SCMI Raw transmission mode to coexist with normal SCMI stack.
+
+	  This will allow regular SCMI drivers to register with the core and
+	  operate normally, thing which could make an SCMI test suite using the
+	  SCMI Raw mode support unreliable. If unsure, say N.
+
 config ARM_SCMI_HAVE_TRANSPORT
 	bool
 	help
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 8601d75f5b9b..68cc4b4290c1 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -59,7 +59,8 @@ static int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
 		 id_table->name, id_table->protocol_id);
 
-	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+	if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT) &&
+	    !IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX)) {
 		pr_warn("SCMI Raw mode active. Rejecting '%s'/0x%02X\n",
 			id_table->name, id_table->protocol_id);
 		return -EINVAL;
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index ad4e53f0c342..282d7737cb8f 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2616,7 +2616,6 @@ static int scmi_debugfs_raw_mode_setup(struct scmi_info *info)
 	info->raw = scmi_raw_mode_init(&info->handle, info->dbg->top_dentry,
 				       info->id, info->desc,
 				       info->tx_minfo.max_msg);
-
 	if (IS_ERR(info->raw)) {
 		dev_err(info->dev, "Failed to initialize SCMI RAW Mode !\n");
 		ret = PTR_ERR(info->raw);
@@ -2706,11 +2705,20 @@ static int scmi_probe(struct platform_device *pdev)
 			dev_warn(dev, "Failed to setup SCMI debugfs.\n");
 
 		if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
+			bool coex =
+			      IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX);
+
 			ret = scmi_debugfs_raw_mode_setup(info);
-			if (ret)
-				goto clear_dev_req_notifier;
+			if (!coex) {
+				if (ret)
+					goto clear_dev_req_notifier;
+
+				/* Bail out anyway when coex enabled */
+				return ret;
+			}
 
-			return 0;
+			/* Coex enabled, carry on in any case. */
+			dev_info(dev, "SCMI RAW Mode COEX enabled !\n");
 		}
 	}
 
diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
index a33ef0eaffe5..037ef9c14fae 100644
--- a/drivers/firmware/arm_scmi/raw_mode.c
+++ b/drivers/firmware/arm_scmi/raw_mode.c
@@ -26,7 +26,10 @@
  * In order to avoid possible interferences between the SCMI Raw transactions
  * originated from a test-suite and the normal operations of the SCMI drivers,
  * when Raw mode is enabled, by default, all the regular SCMI drivers are
- * inhibited.
+ * inhibited, unless CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX is enabled: in this
+ * latter case the regular SCMI stack drivers will be loaded as usual and it is
+ * up to the user of this interface to take care of manually inhibiting the
+ * regular SCMI drivers in order to avoid interferences during the test runs.
  *
  * The exposed API is as follows.
  *
-- 
cgit v1.2.3