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32 .Dt BUS_ALLOC_RESOURCE 9
35 .Nm bus_alloc_resource ,
36 .Nm bus_alloc_resource_any
37 .Nm bus_alloc_resource_anywhere
38 .Nd allocate resources from a parent bus
45 .In machine/resource.h
47 .Fo bus_alloc_resource
48 .Fa "device_t dev" "int type" "int *rid" "rman_res_t start" "rman_res_t end"
49 .Fa "rman_res_t count" "u_int flags"
52 .Fn bus_alloc_resource_any "device_t dev" "int type" "int *rid" "u_int flags"
54 .Fn bus_alloc_resource_anywhere "device_t dev" "int type" "int *rid" "rman_res_t count" "u_int flags"
56 This is an easy interface to the resource-management functions.
57 It hides the indirection through the parent's method table.
58 This function generally should be called in attach, but (except in some
59 rare cases) never earlier.
62 .Fn bus_alloc_resource_any
64 .Fn bus_alloc_resource_anywhere
65 functions are convenience wrappers for
66 .Fn bus_alloc_resource .
67 .Fn bus_alloc_resource_any
73 to the default resource (see description of
76 .Fn bus_alloc_resource_anywhere
81 to the default resource and uses the provided
85 The arguments are as follows:
89 is the device that requests ownership of the resource.
90 Before allocation, the resource is owned by the parent bus.
93 is the type of resource you want to allocate.
95 .Bl -tag -width SYS_RES_MEMORY
100 .It Dv SYS_RES_IOPORT
102 .It Dv SYS_RES_MEMORY
107 points to a bus specific handle that identifies the resource being allocated.
108 For ISA this is an index into an array of resources that have been setup
109 for this device by either the PnP mechanism, or via the hints mechanism.
110 For PCCARD, this is an index into the array of resources described by the PC Card's
112 For PCI, the offset into pci config space which has the BAR to use to access
114 The bus methods are free to change the RIDs that they are given as a parameter.
115 You must not depend on the value you gave it earlier.
120 are the start/end addresses of the resource.
121 If you specify values of 0ul for
127 the default values for the bus are calculated.
130 is the size of the resource.
131 For example, the size of an I/O port is usually 1 byte (but some devices
133 If you specified the default values for
137 then the default value of the bus is used if
139 is smaller than the default value and
141 is used, if it is bigger than the default value.
144 sets the flags for the resource.
145 You can set one or more of these flags:
146 .Bl -tag -width RF_SHAREABLE
148 resource has been reserved.
149 The resource still needs to be activated with
150 .Xr bus_activate_resource 9 .
152 activate resource atomically.
154 resource permits contemporaneous sharing.
155 It should always be set unless you know that the resource cannot be shared.
156 It is the bus driver's task to filter out the flag if the bus does not
160 cannot share IRQs while
164 resource permits time-division sharing.
170 is returned on success, a null pointer otherwise.
172 This is some example code that allocates a 32 byte I/O port range and an IRQ.
177 should be saved in the softc of the device after these calls.
179 struct resource *portres, *irqres;
184 portres = bus_alloc_resource(dev, SYS_RES_IOPORT, &portid,
185 0ul, ~0ul, 32, RF_ACTIVE);
186 irqres = bus_alloc_resource_any(dev, SYS_RES_IRQ, &irqid,
187 RF_ACTIVE | RF_SHAREABLE);
190 .Xr bus_activate_resource 9 ,
191 .Xr bus_adjust_resource 9 ,
192 .Xr bus_release_resource 9 ,
197 This manual page was written by
198 .An Alexander Langer Aq Mt alex@big.endian.de
200 .An Warner Losh Aq Mt imp@FreeBSD.org .