Differential D11963 Diff 31887 share/man/man9/config_intrhook.9

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share/man/man9/config_intrhook.9

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	.Dd September 24, 2006			.Dd August 10, 2017
	.Dt CONFIG_INTRHOOK 9			.Dt CONFIG_INTRHOOK 9
	.Os			.Os
	.Sh NAME			.Sh NAME
	.Nm config_intrhook			.Nm config_intrhook
	.Nd schedule a function to be run after interrupts have been enabled,			.Nd schedule a function to be run after interrupts have been enabled,
	but before root is mounted			but before root is mounted
	.Sh SYNOPSIS			.Sh SYNOPSIS
	.In sys/kernel.h			.In sys/kernel.h
				.Vt typedef void (ich_func_t)(void arg);
	.Ft int			.Ft int
	.Fn config_intrhook_establish "struct intr_config_hook *hook"			.Fn config_intrhook_establish "struct intr_config_hook *hook"
	.Ft void			.Ft void
	.Fn config_intrhook_disestablish "struct intr_config_hook *hook"			.Fn config_intrhook_disestablish "struct intr_config_hook *hook"
				.Ft void
				.Fn config_intrhook_oneshot "ich_func_t func" "void *arg"
	.Sh DESCRIPTION			.Sh DESCRIPTION
	The			The
	.Fn config_intrhook_establish			.Fn config_intrhook_establish
	function schedules a function to be run after interrupts have been			function schedules a function to be run after interrupts have been
	enabled, but before root is mounted.			enabled, but before root is mounted.
	If the system has already passed this point in its initialization,			If the system has already passed this point in its initialization,
	the function is called immediately.			the function is called immediately.
	.Pp			.Pp
	The			The
	.Fn config_intrhook_disestablish			.Fn config_intrhook_disestablish
	function removes the entry from the hook queue.			function removes the entry from the hook queue.
	.Pp			.Pp
				The
				.Fn config_intrhook_oneshot
				function schedules a function to be run as described for
				.Fn config_intrhook_establish ;
				the entry is automatically removed from the hook queue
				after that function runs.
				This is appropriate when additional device configuration must be done
				after interrupts are enabled, but there is no need to stall the
				boot process after that.
				This function allocates memory using M_WAITOK; do not call this while
				holding any non-sleepable locks.
				.Pp
	Before root is mounted, all the previously established hooks are			Before root is mounted, all the previously established hooks are
	run.			run.
	The boot process is then stalled until all handlers remove their hook			The boot process is then stalled until all handlers remove their hook
	from the hook queue with			from the hook queue with
	.Fn config_intrhook_disestablish .			.Fn config_intrhook_disestablish .
	The boot process then proceeds to attempt to mount the root file			The boot process then proceeds to attempt to mount the root file
	system.			system.
	Any driver that can potentially provide devices they wish to be			Any driver that can potentially provide devices they wish to be
	mounted as root must use either this hook, or probe all these devices			mounted as root must use either this hook, or probe all these devices
	in the initial probe.			in the initial probe.
	Since interrupts are disabled during the probe process, many drivers			Since interrupts are disabled during the probe process, many drivers
	need a method to probe for devices with interrupts enabled.			need a method to probe for devices with interrupts enabled.
	.Pp			.Pp
	The requests are made with the			The requests are made with the
	.Vt intr_config_hook			.Vt intr_config_hook
	structure.			structure.
	This structure is defined as follows:			This structure is defined as follows:
	.Bd -literal			.Bd -literal
	struct intr_config_hook {			struct intr_config_hook {
	TAILQ_ENTRY(intr_config_hook) ich_links;/* Private */			TAILQ_ENTRY(intr_config_hook) ich_links;/* Private */
	void (ich_func)(void arg); /* function to call */			ich_func_t ich_func; /* function to call */
	void ich_arg; / Argument to call */			void ich_arg; / Argument to call */
	};			};
	.Ed			.Ed
	.Pp			.Pp
	Storage for the			Storage for the
	.Vt intr_config_hook			.Vt intr_config_hook
	structure must be provided by the driver.			structure must be provided by the driver.
	It must be stable from just before the hook is established until			It must be stable from just before the hook is established until
	after the hook is disestablished.			after the hook is disestablished.
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