1 .\" Copyright (c) 1999 Chris Costello
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36 .Nm destroy_dev_sched ,
37 .Nm destroy_dev_sched_cb ,
38 .Nm destroy_dev_drain ,
42 and DEVFS registration for devices
47 .Fn make_dev "struct cdevsw *cdevsw" "int unit" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
49 .Fn make_dev_cred "struct cdevsw *cdevsw" "int unit" "struct ucred *cr" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
51 .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" ...
53 .Fn make_dev_alias "struct cdev *pdev" "const char *fmt" ...
55 .Fn destroy_dev "struct cdev *dev"
57 .Fn destroy_dev_sched "struct cdev *dev"
59 .Fn destroy_dev_sched_cb "struct cdev *dev" "void (*cb)(void *)" "void *arg"
61 .Fn destroy_dev_drain "struct cdevsw *csw"
63 .Fn dev_depends "struct cdev *pdev" "struct cdev *cdev"
69 structure for a new device.
72 of the presence of the new device, that causes corresponding nodes
77 The device will be owned by
79 with the group ownership as
81 The name is the expansion of
83 and following arguments as
86 The name determines its path under
90 mount point and may contain slash
92 characters to denote subdirectories.
93 The permissions of the file specified in
98 .Bd -literal -offset indent -compact
99 #define S_IRWXU 0000700 /* RWX mask for owner */
100 #define S_IRUSR 0000400 /* R for owner */
101 #define S_IWUSR 0000200 /* W for owner */
102 #define S_IXUSR 0000100 /* X for owner */
104 #define S_IRWXG 0000070 /* RWX mask for group */
105 #define S_IRGRP 0000040 /* R for group */
106 #define S_IWGRP 0000020 /* W for group */
107 #define S_IXGRP 0000010 /* X for group */
109 #define S_IRWXO 0000007 /* RWX mask for other */
110 #define S_IROTH 0000004 /* R for other */
111 #define S_IWOTH 0000002 /* W for other */
112 #define S_IXOTH 0000001 /* X for other */
114 #define S_ISUID 0004000 /* set user id on execution */
115 #define S_ISGID 0002000 /* set group id on execution */
116 #define S_ISVTX 0001000 /* sticky bit */
117 #ifndef _POSIX_SOURCE
118 #define S_ISTXT 0001000
124 argument specifies credentials that will be stored in the
126 member of the initialized
130 argument alters the operation of
132 The following values are currently accepted:
134 .Bd -literal -offset indent -compact
135 MAKEDEV_REF reference the created device
136 MAKEDEV_NOWAIT do not sleep, may return NULL
137 MAKEDEV_WAITOK allow the function to sleep to satisfy malloc
138 MAKEDEV_ETERNAL created device will be never destroyed
143 flag is assumed if none of
150 event handler shall specify
152 flag when creating a device in response to lookup, to avoid race where
153 the device created is destroyed immediately after
155 drops his reference to cdev.
159 flag allows the kernel to not acquire some locks when translating system
160 calls into the cdevsw methods calls.
161 It is responsibility of the driver author to make sure that
163 is never called on the returned cdev.
164 For the convenience, use the
165 .Dv MAKEDEV_ETERNAL_KLD
166 flag for the code that can be compiled into kernel or loaded
167 (and unloaded) as loadable module.
171 function is equivalent to the call
172 .Bd -literal -offset indent
173 make_dev_credf(0, cdevsw, unit, cr, uid, gid, perms, fmt, ...);
178 function call is the same as
179 .Bd -literal -offset indent
180 make_dev_credf(0, cdevsw, unit, NULL, uid, gid, perms, fmt, ...);
185 function takes the returned
189 and makes another (aliased) name for this device.
190 It is an error to call
205 that are available to store state.
206 Both fields are of type
208 These are designed to replace the
212 which can be obtained with
217 function takes the returned
221 and destroys the registration for that device.
222 The notification is sent to
224 about the destruction event.
227 on devices that were created with
232 function establishes a parent-child relationship between two devices.
233 The net effect is that a
235 of the parent device will also result in the destruction of the
238 A device may simultaneously be a parent and a child,
239 so it is possible to build a complete hierarchy.
242 .Fn destroy_dev_sched_cb
243 function schedules execution of the
250 is finished, and if the supplied
252 is not NULL, the callback
254 is called, with argument
257 .Fn destroy_dev_sched
258 function is the same as
259 .Bd -literal -offset indent
260 destroy_dev_sched(cdev, NULL, NULL);
265 driver method cannot call
267 directly. Doing so causes deadlock when
269 waits for all threads to leave the driver methods.
272 sleeps, no non-sleepable locks may be held over the call.
274 .Fn destroy_dev_sched
275 family of functions overcome these issues.
277 The device driver may call the
278 .Fn destroy_dev_drain
279 function to wait until all devices that have supplied
281 as cdevsw, are destroyed. This is useful when driver knows that
282 .Fn destroy_dev_sched
283 is called for all instantiated devices, but need to postpone module
286 is actually finished for all of them.
290 .Xr destroy_dev_drain 9 ,
298 functions first appeared in
310 .Fn destroy_dev_sched ,
311 .Fn destroy_dev_sched_cb