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34 .Nd schedule a function to be run after interrupts have been enabled,
35 but before root is mounted
38 .Vt typedef void (*ich_func_t)(void *arg);
40 .Fn config_intrhook_establish "struct intr_config_hook *hook"
42 .Fn config_intrhook_disestablish "struct intr_config_hook *hook"
44 .Fn config_intrhook_oneshot "ich_func_t func" "void *arg"
47 .Fn config_intrhook_establish
48 function schedules a function to be run after interrupts have been
49 enabled, but before root is mounted.
50 If the system has already passed this point in its initialization,
51 the function is called immediately.
54 .Fn config_intrhook_disestablish
55 function removes the entry from the hook queue.
58 .Fn config_intrhook_oneshot
59 function schedules a function to be run as described for
60 .Fn config_intrhook_establish ;
61 the entry is automatically removed from the hook queue
62 after that function runs.
63 This is appropriate when additional device configuration must be done
64 after interrupts are enabled, but there is no need to stall the
65 boot process after that.
66 This function allocates memory using M_WAITOK; do not call this while
67 holding any non-sleepable locks.
69 Before root is mounted, all the previously established hooks are
71 The boot process is then stalled until all handlers remove their hook
72 from the hook queue with
73 .Fn config_intrhook_disestablish .
74 The boot process then proceeds to attempt to mount the root file
76 Any driver that can potentially provide devices they wish to be
77 mounted as root must use either this hook, or probe all these devices
79 Since interrupts are disabled during the probe process, many drivers
80 need a method to probe for devices with interrupts enabled.
82 The requests are made with the
85 This structure is defined as follows:
87 struct intr_config_hook {
88 TAILQ_ENTRY(intr_config_hook) ich_links;/* Private */
89 ich_func_t ich_func; /* function to call */
90 void *ich_arg; /* Argument to call */
96 structure must be provided by the driver.
97 It must be stable from just before the hook is established until
98 after the hook is disestablished.
100 Specifically, hooks are run at
101 .Fn SI_SUB_INT_CONFIG_HOOKS ,
102 which is immediately after the scheduler is started,
103 and just before the root file system device is discovered.
105 A zero return value means the hook was successfully added to the queue
106 (with either deferred or immediate execution).
107 A non-zero return value means the hook could not be added to the queue
108 because it was already on the queue.
112 These functions were introduced in
114 with the CAM subsystem, but are available for any driver to use.
117 The functions were written by
118 .An Justin Gibbs Aq Mt gibbs@FreeBSD.org .
119 This manual page was written by
120 .An M. Warner Losh Aq Mt imp@FreeBSD.org .