diff options
| -rw-r--r-- | drivers/firmware/arm_scmi/bus.c | 141 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/common.h | 8 | ||||
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 9 | ||||
| -rw-r--r-- | include/linux/scmi_protocol.h | 5 |
4 files changed, 141 insertions, 22 deletions
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; |