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-rw-r--r--drivers/firmware/arm_scmi/bus.c30
-rw-r--r--drivers/firmware/arm_scmi/common.h5
-rw-r--r--drivers/firmware/arm_scmi/driver.c310
3 files changed, 311 insertions, 34 deletions
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index aadf2da21561..784cf0027da3 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -51,6 +51,31 @@ static int scmi_dev_match(struct device *dev, struct device_driver *drv)
return 0;
}
+static int scmi_match_by_id_table(struct device *dev, void *data)
+{
+ struct scmi_device *sdev = to_scmi_dev(dev);
+ struct scmi_device_id *id_table = data;
+
+ return sdev->protocol_id == id_table->protocol_id &&
+ !strcmp(sdev->name, id_table->name);
+}
+
+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;
+
+ id_table.protocol_id = prot_id;
+ id_table.name = name;
+
+ dev = device_find_child(parent, &id_table, scmi_match_by_id_table);
+ if (!dev)
+ return NULL;
+
+ return to_scmi_dev(dev);
+}
+
const struct scmi_protocol *scmi_protocol_get(int protocol_id)
{
const struct scmi_protocol *proto;
@@ -114,6 +139,10 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
{
int retval;
+ retval = scmi_protocol_device_request(driver->id_table);
+ if (retval)
+ return retval;
+
driver->driver.bus = &scmi_bus_type;
driver->driver.name = driver->name;
driver->driver.owner = owner;
@@ -130,6 +159,7 @@ EXPORT_SYMBOL_GPL(scmi_driver_register);
void scmi_driver_unregister(struct scmi_driver *driver)
{
driver_unregister(&driver->driver);
+ scmi_protocol_device_unrequest(driver->id_table);
}
EXPORT_SYMBOL_GPL(scmi_driver_unregister);
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 762dd5419700..228bf4a71d23 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -309,6 +309,11 @@ 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);
+
/**
* struct scmi_desc - Description of SoC integration
*
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index c25c20c150dc..66eb3f0e5daf 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -21,6 +21,7 @@
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
+#include <linux/list.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
@@ -56,6 +57,14 @@ 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);
+
+struct scmi_requested_dev {
+ const struct scmi_device_id *id_table;
+ struct list_head node;
+};
+
/**
* struct scmi_xfers_info - Structure to manage transfer information
*
@@ -113,6 +122,8 @@ struct scmi_protocol_instance {
* @protocols_mtx: A mutex to protect protocols instances initialization.
* @protocols_imp: List of protocols implemented, currently maximum of
* MAX_PROTOCOLS_IMP elements allocated by the base protocol
+ * @active_protocols: IDR storing device_nodes for protocols actually defined
+ * in the DT and confirmed as implemented by fw.
* @notify_priv: Pointer to private data structure specific to notifications.
* @node: List head
* @users: Number of users of this instance
@@ -130,6 +141,7 @@ struct scmi_info {
/* Ensure mutual exclusive access to protocols instance array */
struct mutex protocols_mtx;
u8 *protocols_imp;
+ struct idr active_protocols;
void *notify_priv;
struct list_head node;
int users;
@@ -935,6 +947,13 @@ static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id)
WARN_ON(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
*
@@ -956,8 +975,7 @@ 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 = &info->handle;
- info->users++;
+ handle = scmi_handle_get_from_info_unlocked(info);
break;
}
}
@@ -1100,63 +1118,268 @@ scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
return ret;
}
-static inline void
-scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
- int prot_id, const char *name)
+/**
+ * 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.
+ */
+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;
+
+ 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);
- return;
+ return NULL;
}
if (scmi_txrx_setup(info, &sdev->dev, prot_id)) {
dev_err(&sdev->dev, "failed to setup transport\n");
scmi_device_destroy(sdev);
- return;
+ return NULL;
}
+ 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);
}
-#define MAX_SCMI_DEV_PER_PROTOCOL 2
-struct scmi_prot_devnames {
- int protocol_id;
- char *names[MAX_SCMI_DEV_PER_PROTOCOL];
-};
+/**
+ * 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;
-static struct scmi_prot_devnames devnames[] = {
- { SCMI_PROTOCOL_POWER, { "genpd" },},
- { SCMI_PROTOCOL_SYSTEM, { "syspower" },},
- { SCMI_PROTOCOL_PERF, { "cpufreq" },},
- { SCMI_PROTOCOL_CLOCK, { "clocks" },},
- { SCMI_PROTOCOL_SENSOR, { "hwmon", "iiodev" },},
- { SCMI_PROTOCOL_RESET, { "reset" },},
- { SCMI_PROTOCOL_VOLTAGE, { "regulator" },},
-};
+ mutex_lock(&scmi_requested_devices_mtx);
+ phead = idr_find(&scmi_requested_devices, prot_id);
+ if (phead) {
+ struct scmi_requested_dev *rdev;
-static inline void
-scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info,
- int prot_id)
+ 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 loop, cnt;
+ int ret = 0;
+ unsigned int id = 0;
+ struct list_head *head, *phead = NULL;
+ struct scmi_requested_dev *rdev;
+ struct scmi_info *info;
- for (loop = 0; loop < ARRAY_SIZE(devnames); loop++) {
- if (devnames[loop].protocol_id != prot_id)
- continue;
+ 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);
+ /* Set handle if not already set: device existed */
+ if (sdev && !sdev->handle)
+ sdev->handle =
+ scmi_handle_get_from_info_unlocked(info);
+ } 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);
- for (cnt = 0; cnt < ARRAY_SIZE(devnames[loop].names); cnt++) {
- const char *name = devnames[loop].names[cnt];
+ return ret;
+}
- if (name)
- scmi_create_protocol_device(np, info, prot_id,
- name);
+/**
+ * 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_probe(struct platform_device *pdev)
@@ -1181,6 +1404,7 @@ static int scmi_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&info->node);
idr_init(&info->protocols);
mutex_init(&info->protocols_mtx);
+ idr_init(&info->active_protocols);
platform_set_drvdata(pdev, info);
idr_init(&info->tx_idr);
@@ -1233,6 +1457,19 @@ static int scmi_probe(struct platform_device *pdev)
continue;
}
+ /*
+ * Save this valid DT protocol descriptor amongst
+ * @active_protocols for this SCMI instance/
+ */
+ ret = idr_alloc(&info->active_protocols, child,
+ prot_id, prot_id + 1, GFP_KERNEL);
+ if (ret != prot_id) {
+ dev_err(dev, "SCMI protocol %d already activated. Skip\n",
+ prot_id);
+ continue;
+ }
+
+ of_node_get(child);
scmi_create_protocol_devices(child, info, prot_id);
}
@@ -1246,9 +1483,10 @@ void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id)
static int scmi_remove(struct platform_device *pdev)
{
- int ret = 0;
+ int ret = 0, id;
struct scmi_info *info = platform_get_drvdata(pdev);
struct idr *idr = &info->tx_idr;
+ struct device_node *child;
mutex_lock(&scmi_list_mutex);
if (info->users)
@@ -1266,6 +1504,10 @@ static int scmi_remove(struct platform_device *pdev)
idr_destroy(&info->protocols);
mutex_unlock(&info->protocols_mtx);
+ idr_for_each_entry(&info->active_protocols, child, id)
+ of_node_put(child);
+ idr_destroy(&info->active_protocols);
+
/* Safe to free channels since no more users */
ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
idr_destroy(&info->tx_idr);
generated by cgit (git 2.34.1) at 2024-06-02 09:11:25 +0000