xref: /dragonfly/share/man/man9/BUS_SETUP_INTR.9 (revision f8f04fe3) 
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25.\" $FreeBSD: src/share/man/man9/BUS_SETUP_INTR.9,v 1.20 2007/03/01 14:33:29 ru Exp $
26.\" $DragonFly: src/share/man/man9/BUS_SETUP_INTR.9,v 1.5 2007/04/08 07:05:25 swildner Exp $
27.\"
28.Dd April 7, 2007
29.Dt BUS_SETUP_INTR 9
30.Os
31.Sh NAME
32.Nm BUS_SETUP_INTR ,
33.Nm bus_setup_intr ,
34.Nm BUS_TEARDOWN_INTR ,
35.Nm bus_teardown_intr
36.Nd create, attach and teardown an interrupt handler
37.Sh SYNOPSIS
38.In sys/param.h
39.In sys/bus.h
40.Ft int
41.Fo BUS_SETUP_INTR
42.Fa "device_t dev" "device_t child" "struct resource *irq" "int flags"
43.Fa "driver_intr_t *intr" "void *arg" "void **cookiep"
44.Fa "lwkt_serialize_t serializer"
45.Fc
46.Ft int
47.Fo bus_setup_intr
48.Fa "device_t dev" "struct resource *r" "int flags" "driver_intr_t handler"
49.Fa "void *arg" "void **cookiep" "lwkt_serialize_t serializer"
50.Fc
51.Ft int
52.Fo BUS_TEARDOWN_INTR
53.Fa "device_t dev" "device_t child" "struct resource *irq" "void *cookie"
54.Fc
55.Ft int
56.Fn bus_teardown_intr "device_t dev" "struct resource *r" "void *cookie"
57.Sh DESCRIPTION
58The
59.Fn BUS_SETUP_INTR
60method
61will create and attach an interrupt handler to an interrupt
62previously allocated by the resource manager's
63.Xr BUS_ALLOC_RESOURCE 9
64method.
65The defined handler
66will be called with the value
67.Fa arg
68as its only argument.
69.Pp
70The
71.Fa cookiep
72argument is a pointer to a
73.Vt "void *"
74that
75.Fn BUS_SETUP_INTR
76will write a cookie for the parent bus' use to if it is successful in
77establishing an interrupt.
78Driver writers may assume that this cookie will be non-zero.
79The nexus driver will write 0 on failure to
80.Fa cookiep .
81.Pp
82The
83.Fa flags
84are found in
85.In sys/bus.h
86and tell the interrupt handlers about certain
87device driver characteristics and are typically either
88.Li 0
89or
90.Dv INTR_MPSAFE .
91If
92.Dv INTR_MPSAFE
93is specified the kernel is free to call the interrupt handler without
94holding the MP lock.
95.Dv INTR_FAST
96is also sometimes specified and allows the
97interrupt handler to be directly called from the context of the thread
98being interrupted, but is not recommended for most drivers.
99Other interrupt flags exist for special purposes.
100.Pp
101If
102.Fa serializer
103is non-NULL the interrupt handler will be called with the serializer held.
104The serializer replaces the obsolete SPL calls that are no longer relevant on
105SMP systems.
106Driver code can obtain the same serializer to interlock against
107the driver interrupt.
108The serializer also has enablement and disablement
109features which mainline driver code can use to avoid races between interrupt
110disablement and delayed interrupts executing from the device's interrupt
111thread.
112.Pp
113The interrupt handler will be detached by
114.Fn BUS_TEARDOWN_INTR .
115The
116.Fa cookie
117needs to be passed to
118.Fn BUS_TEARDOWN_INTR
119in order to tear down the correct interrupt handler.
120Once
121.Fn BUS_TEARDOWN_INTR
122returns, it is guaranteed that the interrupt function is not active and
123will no longer be called.
124.Pp
125The lowercase versions
126.Fn bus_setup_intr
127and
128.Fn bus_teardown_intr
129are convenience functions to make it easier for drivers to use the
130resource-management functions.
131All they do is hide indirection through the parent's method table,
132making for slightly less wordy code.
133.Sh RETURN VALUES
134Zero is returned on success,
135otherwise an appropriate error is returned.
136.Sh SEE ALSO
137.Xr device 9 ,
138.Xr driver 9 ,
139.Xr serializer 9
140.Sh AUTHORS
141.An -nosplit
142This manual page was written by
143.An Jeroen Ruigrok van der Werven
144.Aq asmodai@FreeBSD.org
145based on the manual pages for
146.Fn BUS_CREATE_INTR
147and
148.Fn BUS_CONNECT_INTR
149written by
150.An Doug Rabson
151.Aq dfr@FreeBSD.org .
152