diff options
author | Sergey Ryazanov <ryazanov.s.a@gmail.com> | 2021-06-08 07:02:33 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2021-06-08 14:33:43 -0700 |
commit | 9ee23f48f6705fff6c23e02c4ab1e6d99369cd05 (patch) | |
tree | e7833e30a809fd05f5fcf11c46dcd425e5aecc72 /drivers | |
parent | f36a111a74e71edbba27d4c0cf3d7bbccc172108 (diff) | |
download | linux-stable-9ee23f48f6705fff6c23e02c4ab1e6d99369cd05.tar.gz linux-stable-9ee23f48f6705fff6c23e02c4ab1e6d99369cd05.tar.bz2 linux-stable-9ee23f48f6705fff6c23e02c4ab1e6d99369cd05.zip |
wwan_hwsim: add debugfs management interface
wwan_hwsim creates and removes simulated control ports on module loading
and unloading. It would be helpful to be able to create/remove devices
and ports at run-time to trigger wwan port (un-)register actions without
module reloading.
Some simulator objects (e.g. ports) do not have the underling device and
it is not possible to fully manage the simulator via sysfs. wwan_hsim
intend for developers, so implement it as a self-contained debugfs based
management interface.
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/wwan/wwan_hwsim.c | 186 |
1 files changed, 184 insertions, 2 deletions
diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c index 96d25d7e5bb8..472cae544a2b 100644 --- a/drivers/net/wwan/wwan_hwsim.c +++ b/drivers/net/wwan/wwan_hwsim.c @@ -15,6 +15,8 @@ #include <linux/list.h> #include <linux/skbuff.h> #include <linux/wwan.h> +#include <linux/debugfs.h> +#include <linux/workqueue.h> static int wwan_hwsim_devsnum = 2; module_param_named(devices, wwan_hwsim_devsnum, int, 0444); @@ -22,6 +24,9 @@ MODULE_PARM_DESC(devices, "Number of simulated devices"); static struct class *wwan_hwsim_class; +static struct dentry *wwan_hwsim_debugfs_topdir; +static struct dentry *wwan_hwsim_debugfs_devcreate; + static DEFINE_SPINLOCK(wwan_hwsim_devs_lock); static LIST_HEAD(wwan_hwsim_devs); static unsigned int wwan_hwsim_dev_idx; @@ -30,6 +35,9 @@ struct wwan_hwsim_dev { struct list_head list; unsigned int id; struct device dev; + struct work_struct del_work; + struct dentry *debugfs_topdir; + struct dentry *debugfs_portcreate; spinlock_t ports_lock; /* Serialize ports creation/deletion */ unsigned int port_idx; struct list_head ports; @@ -40,6 +48,8 @@ struct wwan_hwsim_port { unsigned int id; struct wwan_hwsim_dev *dev; struct wwan_port *wwan; + struct work_struct del_work; + struct dentry *debugfs_topdir; enum { /* AT command parser state */ AT_PARSER_WAIT_A, AT_PARSER_WAIT_T, @@ -48,6 +58,12 @@ struct wwan_hwsim_port { } pstate; }; +static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops; +static const struct file_operations wwan_hwsim_debugfs_portcreate_fops; +static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops; +static void wwan_hwsim_port_del_work(struct work_struct *work); +static void wwan_hwsim_dev_del_work(struct work_struct *work); + static int wwan_hwsim_port_start(struct wwan_port *wport) { struct wwan_hwsim_port *port = wwan_port_get_drvdata(wport); @@ -139,6 +155,7 @@ static const struct wwan_port_ops wwan_hwsim_port_ops = { static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev) { struct wwan_hwsim_port *port; + char name[0x10]; int err; port = kzalloc(sizeof(*port), GFP_KERNEL); @@ -159,6 +176,13 @@ static struct wwan_hwsim_port *wwan_hwsim_port_new(struct wwan_hwsim_dev *dev) goto err_free_port; } + INIT_WORK(&port->del_work, wwan_hwsim_port_del_work); + + snprintf(name, sizeof(name), "port%u", port->id); + port->debugfs_topdir = debugfs_create_dir(name, dev->debugfs_topdir); + debugfs_create_file("destroy", 0200, port->debugfs_topdir, port, + &wwan_hwsim_debugfs_portdestroy_fops); + return port; err_free_port: @@ -169,10 +193,34 @@ err_free_port: static void wwan_hwsim_port_del(struct wwan_hwsim_port *port) { + debugfs_remove(port->debugfs_topdir); + + /* Make sure that there is no pending deletion work */ + if (current_work() != &port->del_work) + cancel_work_sync(&port->del_work); + wwan_remove_port(port->wwan); kfree(port); } +static void wwan_hwsim_port_del_work(struct work_struct *work) +{ + struct wwan_hwsim_port *port = + container_of(work, typeof(*port), del_work); + struct wwan_hwsim_dev *dev = port->dev; + + spin_lock(&dev->ports_lock); + if (list_empty(&port->list)) { + /* Someone else deleting port at the moment */ + spin_unlock(&dev->ports_lock); + return; + } + list_del_init(&port->list); + spin_unlock(&dev->ports_lock); + + wwan_hwsim_port_del(port); +} + static void wwan_hwsim_dev_release(struct device *sysdev) { struct wwan_hwsim_dev *dev = container_of(sysdev, typeof(*dev), dev); @@ -204,6 +252,17 @@ static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void) if (err) goto err_free_dev; + INIT_WORK(&dev->del_work, wwan_hwsim_dev_del_work); + + dev->debugfs_topdir = debugfs_create_dir(dev_name(&dev->dev), + wwan_hwsim_debugfs_topdir); + debugfs_create_file("destroy", 0200, dev->debugfs_topdir, dev, + &wwan_hwsim_debugfs_devdestroy_fops); + dev->debugfs_portcreate = + debugfs_create_file("portcreate", 0200, + dev->debugfs_topdir, dev, + &wwan_hwsim_debugfs_portcreate_fops); + return dev; err_free_dev: @@ -214,23 +273,136 @@ err_free_dev: static void wwan_hwsim_dev_del(struct wwan_hwsim_dev *dev) { + debugfs_remove(dev->debugfs_portcreate); /* Avoid new ports */ + spin_lock(&dev->ports_lock); while (!list_empty(&dev->ports)) { struct wwan_hwsim_port *port; port = list_first_entry(&dev->ports, struct wwan_hwsim_port, list); - list_del(&port->list); + list_del_init(&port->list); spin_unlock(&dev->ports_lock); wwan_hwsim_port_del(port); spin_lock(&dev->ports_lock); } spin_unlock(&dev->ports_lock); + debugfs_remove(dev->debugfs_topdir); + + /* Make sure that there is no pending deletion work */ + if (current_work() != &dev->del_work) + cancel_work_sync(&dev->del_work); + device_unregister(&dev->dev); /* Memory will be freed in the device release callback */ } +static void wwan_hwsim_dev_del_work(struct work_struct *work) +{ + struct wwan_hwsim_dev *dev = container_of(work, typeof(*dev), del_work); + + spin_lock(&wwan_hwsim_devs_lock); + if (list_empty(&dev->list)) { + /* Someone else deleting device at the moment */ + spin_unlock(&wwan_hwsim_devs_lock); + return; + } + list_del_init(&dev->list); + spin_unlock(&wwan_hwsim_devs_lock); + + wwan_hwsim_dev_del(dev); +} + +static ssize_t wwan_hwsim_debugfs_portdestroy_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_port *port = file->private_data; + + /* We can not delete port here since it will cause a deadlock due to + * waiting this callback to finish in the debugfs_remove() call. So, + * use workqueue. + */ + schedule_work(&port->del_work); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_portdestroy_fops = { + .write = wwan_hwsim_debugfs_portdestroy_write, + .open = simple_open, + .llseek = noop_llseek, +}; + +static ssize_t wwan_hwsim_debugfs_portcreate_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_dev *dev = file->private_data; + struct wwan_hwsim_port *port; + + port = wwan_hwsim_port_new(dev); + if (IS_ERR(port)) + return PTR_ERR(port); + + spin_lock(&dev->ports_lock); + list_add_tail(&port->list, &dev->ports); + spin_unlock(&dev->ports_lock); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_portcreate_fops = { + .write = wwan_hwsim_debugfs_portcreate_write, + .open = simple_open, + .llseek = noop_llseek, +}; + +static ssize_t wwan_hwsim_debugfs_devdestroy_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_dev *dev = file->private_data; + + /* We can not delete device here since it will cause a deadlock due to + * waiting this callback to finish in the debugfs_remove() call. So, + * use workqueue. + */ + schedule_work(&dev->del_work); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_devdestroy_fops = { + .write = wwan_hwsim_debugfs_devdestroy_write, + .open = simple_open, + .llseek = noop_llseek, +}; + +static ssize_t wwan_hwsim_debugfs_devcreate_write(struct file *file, + const char __user *usrbuf, + size_t count, loff_t *ppos) +{ + struct wwan_hwsim_dev *dev; + + dev = wwan_hwsim_dev_new(); + if (IS_ERR(dev)) + return PTR_ERR(dev); + + spin_lock(&wwan_hwsim_devs_lock); + list_add_tail(&dev->list, &wwan_hwsim_devs); + spin_unlock(&wwan_hwsim_devs_lock); + + return count; +} + +static const struct file_operations wwan_hwsim_debugfs_devcreate_fops = { + .write = wwan_hwsim_debugfs_devcreate_write, + .open = simple_open, + .llseek = noop_llseek, +}; + static int __init wwan_hwsim_init_devs(void) { struct wwan_hwsim_dev *dev; @@ -272,7 +444,7 @@ static void wwan_hwsim_free_devs(void) while (!list_empty(&wwan_hwsim_devs)) { dev = list_first_entry(&wwan_hwsim_devs, struct wwan_hwsim_dev, list); - list_del(&dev->list); + list_del_init(&dev->list); spin_unlock(&wwan_hwsim_devs_lock); wwan_hwsim_dev_del(dev); spin_lock(&wwan_hwsim_devs_lock); @@ -291,6 +463,12 @@ static int __init wwan_hwsim_init(void) if (IS_ERR(wwan_hwsim_class)) return PTR_ERR(wwan_hwsim_class); + wwan_hwsim_debugfs_topdir = debugfs_create_dir("wwan_hwsim", NULL); + wwan_hwsim_debugfs_devcreate = + debugfs_create_file("devcreate", 0200, + wwan_hwsim_debugfs_topdir, NULL, + &wwan_hwsim_debugfs_devcreate_fops); + err = wwan_hwsim_init_devs(); if (err) goto err_clean_devs; @@ -299,6 +477,7 @@ static int __init wwan_hwsim_init(void) err_clean_devs: wwan_hwsim_free_devs(); + debugfs_remove(wwan_hwsim_debugfs_topdir); class_destroy(wwan_hwsim_class); return err; @@ -306,7 +485,10 @@ err_clean_devs: static void __exit wwan_hwsim_exit(void) { + debugfs_remove(wwan_hwsim_debugfs_devcreate); /* Avoid new devs */ wwan_hwsim_free_devs(); + flush_scheduled_work(); /* Wait deletion works completion */ + debugfs_remove(wwan_hwsim_debugfs_topdir); class_destroy(wwan_hwsim_class); } |