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28 .Dd April 29, 2007
29 .Dt RMAN 9
30 .Os
31 .Sh NAME
32 .Nm rman ,
33 .Nm rman_activate_resource ,
34 .Nm rman_await_resource ,
35 .Nm rman_deactivate_resource ,
36 .Nm rman_fini ,
37 .Nm rman_init ,
38 .Nm rman_manage_region ,
39 .Nm rman_release_resource ,
40 .Nm rman_reserve_resource ,
41 .Nm rman_reserve_resource_bound ,
42 .Nm rman_make_alignment_flags ,
43 .Nm rman_get_start ,
44 .Nm rman_get_end ,
45 .Nm rman_get_device ,
46 .Nm rman_get_size ,
47 .Nm rman_get_flags ,
48 .Nm rman_set_virtual ,
49 .Nm rman_get_virtual ,
50 .Nm rman_set_bustag ,
51 .Nm rman_get_bustag ,
52 .Nm rman_set_bushandle ,
53 .Nm rman_get_bushandle ,
54 .Nm rman_set_rid ,
55 .Nm rman_get_rid
56 .Nd resource management functions
57 .Sh SYNOPSIS
58 .In sys/rman.h
59 .Ft int
60 .Fn rman_activate_resource "struct resource *r"
61 .Ft int
62 .Fn rman_await_resource "struct resource *r" "int pri2" "int timo"
63 .Ft int
64 .Fn rman_deactivate_resource "struct resource *r"
65 .Ft int
66 .Fn rman_fini "struct rman *rm"
67 .Ft int
68 .Fn rman_init "struct rman *rm"
69 .Ft int
70 .Fn rman_manage_region "struct rman *rm" "u_long start" "u_long end"
71 .Ft int
72 .Fn rman_release_resource "struct resource *r"
73 .Ft "struct resource *"
74 .Fo rman_reserve_resource
75 .Fa "struct rman *rm" "u_long start" "u_long end" "u_long count"
76 .Fa "u_int flags" "struct device *dev"
77 .Fc
78 .Ft "struct resource *"
79 .Fo rman_reserve_resource_bound
80 .Fa "struct rman *rm" "u_long start" "u_long end" "u_long count"
81 .Fa "u_long bound" "u_int flags" "struct device *dev"
82 .Fc
83 .Ft uint32_t
84 .Fn rman_make_alignment_flags "uint32_t size"
85 .Ft u_long
86 .Fn rman_get_start "struct resource *r"
87 .Ft u_long
88 .Fn rman_get_end "struct resource *r"
89 .Ft "struct device *"
90 .Fn rman_get_device "struct resource *r"
91 .Ft u_long
92 .Fn rman_get_size "struct resource *r"
93 .Ft u_int
94 .Fn rman_get_flags "struct resource *r"
95 .Ft void
96 .Fn rman_set_virtual "struct resource *r" "void *v"
97 .Ft "void *"
98 .Fn rman_get_virtual "struct resource *r"
99 .Ft void
100 .Fn rman_set_bustag "struct resource *r" "bus_space_tag_t t"
101 .Ft bus_space_tag_t
102 .Fn rman_get_bustag "struct resource *r"
103 .Ft void
104 .Fn rman_set_bushandle "struct resource *r" "bus_space_handle_t h"
105 .Ft bus_space_handle_t
106 .Fn rman_get_bushandle "struct resource *r"
107 .Ft void
108 .Fn rman_set_rid "struct resource *r" "int rid"
109 .Ft int
110 .Fn rman_get_rid "struct resource *r"
111 .Sh DESCRIPTION
112 The
113 .Nm
114 set of functions provides a flexible resource management abstraction.
115 It is used extensively by the bus management code.
116 It implements the abstractions of region and resource.
117 A region descriptor is used to manage a region; this could be memory or
118 some other form of bus space.
119 .Pp
120 Each region has a set of bounds.
121 Within these bounds, allocated segments may reside.
122 Each segment, termed a resource, has several properties which are
123 represented by a 16-bit flag register, as follows.
124 .Bd -literal
125 #define RF_ALLOCATED 0x0001 /* resource has been reserved */
126 #define RF_ACTIVE 0x0002 /* resource allocation has been activated */
127 #define RF_SHAREABLE 0x0004 /* resource permits contemporaneous sharing */
128 #define RF_TIMESHARE 0x0008 /* resource permits time-division sharing */
129 #define RF_WANTED 0x0010 /* somebody is waiting for this resource */
130 #define RF_FIRSTSHARE 0x0020 /* first in sharing list */
131 #define RF_PREFETCHABLE 0x0040 /* resource is prefetchable */
132 .Ed
133 .Pp
134 The remainder of the flag bits are used to represent the desired alignment
135 of the resource within the region.
136 .Pp
137 The
138 .Fn rman_init
139 function initializes the region descriptor, pointed to by the
140 .Fa rm
141 argument, for use with the resource management functions.
142 It is required that the fields
143 .Va rm_type
144 and
145 .Va rm_descr
146 of
147 .Vt "struct rman"
148 be set before calling
149 .Fn rman_init .
150 The field
151 .Va rm_type
152 shall be set to
153 .Dv RMAN_ARRAY .
154 The field
155 .Va rm_descr
156 shall be set to a string that describes the resource to be managed.
157 It also initializes any mutexes associated with the structure.
158 If
159 .Fn rman_init
160 fails to initalize the mutex, it will return
161 .Er ENOMEM ; otherwise it will return 0 and
162 .Fa rm
163 will be initalized.
164 .Pp
165 The
166 .Fn rman_fini
167 function frees any structures associated with the structure
168 pointed to by the
169 .Fa rm
170 argument.
171 If any of the resources within the managed region have the
172 .Dv RF_ALLOCATED
173 flag set, it will return
174 .Er EBUSY ;
175 otherwise, any mutexes associated with the structure will be released
176 and destroyed, and the function will return 0.
177 .Pp
178 The
179 .Fn rman_manage_region
180 function establishes the concept of a region which is under
181 .Nm
182 control.
183 The
184 .Fa rman
185 argument points to the region descriptor.
186 The
187 .Fa start
188 and
189 .Fa end
190 arguments specify the bounds of the region.
191 If successful,
192 .Fn rman_manage_region
193 will return 0.
194 If the region overlaps with an existing region, it will return
195 .Er EBUSY .
196 .Er ENOMEM
197 will be return when
198 .Fn rman_manage_region
199 failed to allocate memory for the region.
200 .Pp
201 The
202 .Fn rman_reserve_resource_bound
203 function is where the bulk of the
204 .Nm
205 logic is located.
206 It attempts to reserve a contiguous range in the specified region
207 .Fa rm
208 for the use of the device
209 .Fa dev .
210 The caller can specify the
211 .Fa start
212 and
213 .Fa end
214 of an acceptable range, as well as
215 alignment, and the code will attempt to find a free segment which fits.
216 The
217 .Fa start
218 argument is the lowest acceptable starting value of the resource.
219 The
220 .Fa end
221 argument is the highest acceptable ending value of the resource.
222 Therefore,
223 .Fa start No + Fa count No \- 1
224 must be \[<=]
225 .Fa end
226 for any allocation to happen.
227 The default behavior is to allocate an exclusive segment, unless the
228 .Dv RF_SHAREABLE
229 or
230 .Dv RF_TIMESHARE
231 flags are set, in which case a shared
232 segment will be allocated.
233 If this shared segment already exists, the caller has its device
234 added to the list of consumers.
235 .Pp
236 The
237 .Fn rman_reserve_resource
238 function is used to reserve resources within a previously established region.
239 It is a simplified interface to
240 .Fn rman_reserve_resource_bound
241 which passes 0 for the
242 .Fa flags
243 argument.
244 .Pp
245 The
246 .Fn rman_make_alignment_flags
247 function returns the flag mask corresponding to the desired alignment
248 .Fa size .
249 This should be used when calling
250 .Fn rman_reserve_resource_bound .
251 .Pp
252 The
253 .Fn rman_release_resource
254 function releases the reserved resource
255 .Fa r .
256 It may attempt to merge adjacent free resources.
257 .Pp
258 The
259 .Fn rman_activate_resource
260 function marks a resource as active, by setting the
261 .Dv RF_ACTIVE
262 flag.
263 If this is a time shared resource, and the caller has not yet acquired
264 the resource, the function returns
265 .Er EBUSY .
266 .Pp
267 The
268 .Fn rman_deactivate_resource
269 function marks a resource
270 .Fa r
271 as inactive, by clearing the
272 .Dv RF_ACTIVE
273 flag.
274 If other consumers are waiting for this range, it will wakeup their threads.
275 .Pp
276 The
277 .Fn rman_await_resource
278 function performs an asynchronous wait for a resource
279 .Fa r
280 to become inactive, that is, for the
281 .Dv RF_ACTIVE
282 flag to be cleared.
283 It is used to enable cooperative sharing of a resource
284 which can only be safely used by one thread at a time.
285 The arguments
286 .Fa pri
287 and
288 .Fa timo
289 are passed to the
290 .Fn rman_await_resource
291 function.
292 .Pp
293 The
294 .Fn rman_get_start ,
295 .Fn rman_get_end ,
296 .Fn rman_get_size ,
297 and
298 .Fn rman_get_flags
299 functions return the bounds, size and flags of the previously reserved
300 resource
301 .Fa r .
302 .Pp
303 The
304 .Fn rman_set_bustag
305 function associates a
306 .Vt bus_space_tag_t
307 .Fa t
308 with the resource
309 .Fa r .
310 The
311 .Fn rman_get_bustag
312 function is used to retrieve this tag once set.
313 .Pp
314 The
315 .Fn rman_set_bushandle
316 function associates a
317 .Vt bus_space_handle_t
318 .Fa h
319 with the resource
320 .Fa r .
321 The
322 .Fn rman_get_bushandle
323 function is used to retrieve this handle once set.
324 .Pp
325 The
326 .Fn rman_set_virtual
327 function is used to associate a kernel virtual address with a resource
328 .Fa r .
329 The
330 .Fn rman_get_virtual
331 function can be used to retrieve the KVA once set.
332 .Pp
333 The
334 .Fn rman_set_rid
335 function associates a resource identifier with a resource
336 .Fa r .
337 The
338 .Fn rman_get_rid
339 function retrieves this RID.
340 .Pp
341 The
342 .Fn rman_get_device
343 function returns a pointer to the device which reserved the resource
344 .Fa r .
345 .Sh SEE ALSO
346 .Xr bus_activate_resource 9 ,
347 .Xr bus_alloc_resource 9 ,
348 .Xr bus_release_resource 9 ,
349 .Xr bus_set_resource 9 ,
350 .Xr mutex 9
351 .Sh AUTHORS
352 This manual page was written by
353 .An Bruce M Simpson Aq bms@spc.org .