#include <linux/types.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
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)
{
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;
}
/* 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
*
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;
}
of_node_get(child);
- scmi_create_protocol_devices(child, info, prot_id);
}
return 0;
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