From c4804670026b93f4ebddda30af89fd737bf93931 Mon Sep 17 00:00:00 2001 From: M Chetan Kumar Date: Sat, 20 Nov 2021 21:51:54 +0530 Subject: net: wwan: common debugfs base dir for wwan device This patch set brings in a common debugfs base directory i.e. /sys/kernel/debugfs/wwan/ in WWAN Subsystem for a WWAN device instance. So that it avoids driver polluting debugfs root with unrelated directories & possible name collusion. Having a common debugfs base directory for WWAN drivers eases user to match control devices with debugfs entries. WWAN Subsystem creates dentry (/sys/kernel/debugfs/wwan) on module load & removes dentry on module unload. When driver registers a new wwan device, dentry (wwanX) is created for WWAN device instance & on driver unregister dentry is removed. New API is introduced to return the wwan device instance dentry so that driver can create debugfs entries under it. Signed-off-by: M Chetan Kumar Reviewed-by: Loic Poulain Signed-off-by: David S. Miller --- drivers/net/wwan/wwan_core.c | 30 ++++++++++++++++++++++++++++-- include/linux/wwan.h | 2 ++ 2 files changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/net/wwan/wwan_core.c b/drivers/net/wwan/wwan_core.c index d293ab688044..5bf62dc35ac7 100644 --- a/drivers/net/wwan/wwan_core.c +++ b/drivers/net/wwan/wwan_core.c @@ -3,6 +3,7 @@ #include #include +#include #include #include #include @@ -25,6 +26,7 @@ static DEFINE_IDA(minors); /* minors for WWAN port chardevs */ static DEFINE_IDA(wwan_dev_ids); /* for unique WWAN device IDs */ static struct class *wwan_class; static int wwan_major; +static struct dentry *wwan_debugfs_dir; #define to_wwan_dev(d) container_of(d, struct wwan_device, dev) #define to_wwan_port(d) container_of(d, struct wwan_port, dev) @@ -40,6 +42,7 @@ static int wwan_major; * @port_id: Current available port ID to pick. * @ops: wwan device ops * @ops_ctxt: context to pass to ops + * @debugfs_dir: WWAN device debugfs dir */ struct wwan_device { unsigned int id; @@ -47,6 +50,7 @@ struct wwan_device { atomic_t port_id; const struct wwan_ops *ops; void *ops_ctxt; + struct dentry *debugfs_dir; }; /** @@ -142,6 +146,18 @@ static struct wwan_device *wwan_dev_get_by_name(const char *name) return to_wwan_dev(dev); } +struct dentry *wwan_get_debugfs_dir(struct device *parent) +{ + struct wwan_device *wwandev; + + wwandev = wwan_dev_get_by_parent(parent); + if (IS_ERR(wwandev)) + return ERR_CAST(wwandev); + + return wwandev->debugfs_dir; +} +EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir); + /* This function allocates and registers a new WWAN device OR if a WWAN device * already exist for the given parent, it gets a reference and return it. * This function is not exported (for now), it is called indirectly via @@ -150,6 +166,7 @@ static struct wwan_device *wwan_dev_get_by_name(const char *name) static struct wwan_device *wwan_create_dev(struct device *parent) { struct wwan_device *wwandev; + const char *wwandev_name; int err, id; /* The 'find-alloc-register' operation must be protected against @@ -189,6 +206,10 @@ static struct wwan_device *wwan_create_dev(struct device *parent) goto done_unlock; } + wwandev_name = kobject_name(&wwandev->dev.kobj); + wwandev->debugfs_dir = debugfs_create_dir(wwandev_name, + wwan_debugfs_dir); + done_unlock: mutex_unlock(&wwan_register_lock); @@ -218,10 +239,12 @@ static void wwan_remove_dev(struct wwan_device *wwandev) else ret = device_for_each_child(&wwandev->dev, NULL, is_wwan_child); - if (!ret) + if (!ret) { + debugfs_remove_recursive(wwandev->debugfs_dir); device_unregister(&wwandev->dev); - else + } else { put_device(&wwandev->dev); + } mutex_unlock(&wwan_register_lock); } @@ -1117,6 +1140,8 @@ static int __init wwan_init(void) goto destroy; } + wwan_debugfs_dir = debugfs_create_dir("wwan", NULL); + return 0; destroy: @@ -1128,6 +1153,7 @@ unregister: static void __exit wwan_exit(void) { + debugfs_remove_recursive(wwan_debugfs_dir); __unregister_chrdev(wwan_major, 0, WWAN_MAX_MINORS, "wwan_port"); rtnl_link_unregister(&wwan_rtnl_link_ops); class_destroy(wwan_class); diff --git a/include/linux/wwan.h b/include/linux/wwan.h index 9fac819f92e3..1646aa3e6779 100644 --- a/include/linux/wwan.h +++ b/include/linux/wwan.h @@ -171,4 +171,6 @@ int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, void wwan_unregister_ops(struct device *parent); +struct dentry *wwan_get_debugfs_dir(struct device *parent); + #endif /* __WWAN_H */ -- cgit