1 .\" Copyright (c) 1999 Chris Costello
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36 .Nm make_dev_alias_p ,
38 .Nm destroy_dev_sched ,
39 .Nm destroy_dev_sched_cb ,
40 .Nm destroy_dev_drain ,
44 and DEVFS registration for devices
49 .Fn make_dev "struct cdevsw *cdevsw" "int unit" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
51 .Fn make_dev_cred "struct cdevsw *cdevsw" "int unit" "struct ucred *cr" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
53 .Fn make_dev_credf "int flags" "struct cdevsw *cdevsw" "int unit" "struct ucred *cr" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
55 .Fn make_dev_p "int flags" "struct cdev **cdev" "struct cdevsw *devsw" "struct ucred *cr" "uid_t uid" "gid_t gid" "int mode" "const char *fmt" ...
57 .Fn make_dev_alias "struct cdev *pdev" "const char *fmt" ...
59 .Fn make_dev_alias_p "int flags" "struct cdev **cdev" "struct cdev *pdev" "const char *fmt" ...
61 .Fn destroy_dev "struct cdev *dev"
63 .Fn destroy_dev_sched "struct cdev *dev"
65 .Fn destroy_dev_sched_cb "struct cdev *dev" "void (*cb)(void *)" "void *arg"
67 .Fn destroy_dev_drain "struct cdevsw *csw"
69 .Fn dev_depends "struct cdev *pdev" "struct cdev *cdev"
75 structure for a new device.
78 of the presence of the new device, that causes corresponding nodes
83 The device will be owned by
85 with the group ownership as
87 The name is the expansion of
89 and following arguments as
92 The name determines its path under
96 mount point and may contain slash
98 characters to denote subdirectories.
99 The permissions of the file specified in
104 .Bd -literal -offset indent -compact
105 #define S_IRWXU 0000700 /* RWX mask for owner */
106 #define S_IRUSR 0000400 /* R for owner */
107 #define S_IWUSR 0000200 /* W for owner */
108 #define S_IXUSR 0000100 /* X for owner */
110 #define S_IRWXG 0000070 /* RWX mask for group */
111 #define S_IRGRP 0000040 /* R for group */
112 #define S_IWGRP 0000020 /* W for group */
113 #define S_IXGRP 0000010 /* X for group */
115 #define S_IRWXO 0000007 /* RWX mask for other */
116 #define S_IROTH 0000004 /* R for other */
117 #define S_IWOTH 0000002 /* W for other */
118 #define S_IXOTH 0000001 /* X for other */
120 #define S_ISUID 0004000 /* set user id on execution */
121 #define S_ISGID 0002000 /* set group id on execution */
122 #define S_ISVTX 0001000 /* sticky bit */
123 #ifndef _POSIX_SOURCE
124 #define S_ISTXT 0001000
130 argument specifies credentials that will be stored in the
132 member of the initialized
136 argument alters the operation of
140 The following values are currently accepted:
142 .Bl -tag -width "MAKEDEV_CHECKNAME" -compact -offset indent
144 reference the created device
146 do not sleep, the call may fail
148 allow the function to sleep to satisfy malloc
150 created device will be never destroyed
151 .It MAKEDEV_CHECKNAME
152 return an error if the device name is invalid or already exists
159 .Dv MAKEDEV_CHECKNAME
160 values are accepted for the
166 flag is assumed if none of
173 event handler shall specify
175 flag when creating a device in response to lookup, to avoid race where
176 the device created is destroyed immediately after
178 drops his reference to cdev.
182 flag allows the kernel to not acquire some locks when translating system
183 calls into the cdevsw methods calls.
184 It is responsibility of the driver author to make sure that
186 is never called on the returned cdev.
187 For the convenience, use the
188 .Dv MAKEDEV_ETERNAL_KLD
189 flag for the code that can be compiled into kernel or loaded
190 (and unloaded) as loadable module.
192 A panic will occur if the MAKEDEV_CHECKNAME flag is not specified
193 and the device name is invalid or already exists.
197 function is equivalent to the call
198 .Bd -literal -offset indent
199 make_dev_credf(0, cdevsw, unit, cr, uid, gid, perms, fmt, ...);
204 function call is the same as
205 .Bd -literal -offset indent
206 make_dev_credf(0, cdevsw, unit, NULL, uid, gid, perms, fmt, ...);
211 function is similar to
213 but it may return an error number and takes a pointer to the resulting
219 function takes the returned
223 and makes another (aliased) name for this device.
224 It is an error to call
230 function is similar to
232 but it takes a pointer to the resulting
234 as an argument and may return an error.
246 that are available to store state.
247 Both fields are of type
249 These are designed to replace the
253 which can be obtained with
258 function takes the returned
262 and destroys the registration for that device.
263 The notification is sent to
265 about the destruction event.
268 on devices that were created with
273 function establishes a parent-child relationship between two devices.
274 The net effect is that a
276 of the parent device will also result in the destruction of the
279 A device may simultaneously be a parent and a child,
280 so it is possible to build a complete hierarchy.
283 .Fn destroy_dev_sched_cb
284 function schedules execution of the
291 is finished, and if the supplied
297 is called, with argument
300 .Fn destroy_dev_sched
301 function is the same as
302 .Bd -literal -offset indent
303 destroy_dev_sched_cb(cdev, NULL, NULL);
308 driver method cannot call
311 Doing so causes deadlock when
313 waits for all threads to leave the driver methods.
316 sleeps, no non-sleepable locks may be held over the call.
318 .Fn destroy_dev_sched
319 family of functions overcome these issues.
321 The device driver may call the
322 .Fn destroy_dev_drain
323 function to wait until all devices that have supplied
325 as cdevsw, are destroyed.
326 This is useful when driver knows that
327 .Fn destroy_dev_sched
328 is called for all instantiated devices, but need to postpone module
331 is actually finished for all of them.
335 will return 0, otherwise it will return an error.
340 pointer, otherwise it will return
347 call will fail and the device will be not registered if:
352 flag was specified and a memory allocation request could not be satisfied.
353 .It Bq Er ENAMETOOLONG
355 .Dv MAKEDEV_CHECKNAME
356 flag was specified and the provided device name is longer than
360 .Dv MAKEDEV_CHECKNAME
361 flag was specified and the provided device name is empty, contains a
365 path component or ends with
369 .Dv MAKEDEV_CHECKNAME
370 flag was specified and the provided device name already exists.
376 .Xr destroy_dev_drain 9 ,
383 functions first appeared in
395 .Fn destroy_dev_sched ,
396 .Fn destroy_dev_sched_cb