xref: /dragonfly/share/man/man9/rman.9 (revision ae24b5e0)
1.\"
2.\" Copyright (c) 2004 The DragonFly Project.  All rights reserved.
3.\"
4.\" This code is derived from software contributed to The DragonFly Project
5.\" by Hiten Pandya <hmp@backplane.com>.
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34.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org>
35.\" All rights reserved.
36.\"
37.\" Redistribution and use in source and binary forms, with or without
38.\" modification, are permitted provided that the following conditions
39.\" are met:
40.\" 1. Redistributions of source code must retain the above copyright
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58.\" $FreeBSD: src/share/man/man9/rman.9,v 1.2 2003/05/30 21:13:32 ru Exp $
59.\"
60.Dd November 29, 2016
61.Dt RMAN 9
62.Os
63.Sh NAME
64.Nm rman ,
65.Nm rman_activate_resource ,
66.\".Nm rman_await_resource ,
67.Nm rman_deactivate_resource ,
68.Nm rman_fini ,
69.Nm rman_init ,
70.Nm rman_manage_region ,
71.Nm rman_release_resource ,
72.Nm rman_reserve_resource ,
73.\".Nm rman_reserve_resource_bound ,
74.Nm rman_make_alignment_flags ,
75.Nm rman_get_start ,
76.Nm rman_get_end ,
77.Nm rman_get_device ,
78.Nm rman_get_size ,
79.Nm rman_get_flags ,
80.Nm rman_set_virtual ,
81.Nm rman_get_virtual ,
82.Nm rman_set_bustag ,
83.Nm rman_get_bustag ,
84.Nm rman_set_bushandle ,
85.Nm rman_get_bushandle
86.\".Nm rman_set_rid ,
87.\".Nm rman_get_rid
88.Nd resource management functions
89.Sh SYNOPSIS
90.In sys/param.h
91.In sys/rman.h
92.Ft int
93.Fn rman_activate_resource "struct resource *r"
94.\".Ft int
95.\".Fn rman_await_resource "struct resource *r" "int pri2" "int timo"
96.Ft int
97.Fn rman_deactivate_resource "struct resource *r"
98.Ft int
99.Fn rman_fini "struct rman *rm"
100.Ft int
101.Fn rman_init "struct rman *rm" "int cpuid"
102.Ft int
103.Fn rman_manage_region "struct rman *rm" "u_long start" "u_long end"
104.Ft int
105.Fn rman_release_resource "struct resource *r"
106.Ft "struct resource *"
107.Fo rman_reserve_resource
108.Fa "struct rman *rm" "u_long start" "u_long end" "u_long count"
109.Fa "u_int flags" "device_t dev"
110.Fc
111.\".Ft "struct resource *"
112.\".Fo rman_reserve_resource_bound
113.\".Fa "struct rman *rm" "u_long start" "u_long end" "u_long count"
114.\".Fa "u_long bound" "u_int flags" "device_t dev"
115.\".Fc
116.Ft uint32_t
117.Fn rman_make_alignment_flags "uint32_t size"
118.Pp
119.Ft u_long
120.Fn rman_get_start "struct resource *r"
121.Ft u_long
122.Fn rman_get_end "struct resource *r"
123.Ft device_t
124.Fn rman_get_device "struct resource *r"
125.Ft u_long
126.Fn rman_get_size "struct resource *r"
127.Ft u_int
128.Fn rman_get_flags "struct resource *r"
129.Ft void
130.Fn rman_set_virtual "struct resource *r" "void *v"
131.Ft "void *"
132.Fn rman_get_virtual "struct resource *r"
133.Ft void
134.Fn rman_set_bustag "struct resource *r" "bus_space_tag_t t"
135.Ft bus_space_tag_t
136.Fn rman_get_bustag "struct resource *r"
137.Ft void
138.Fn rman_set_bushandle "struct resource *r" "bus_space_handle_t h"
139.Ft bus_space_handle_t
140.Fn rman_get_bushandle "struct resource *r"
141.\".Ft void
142.\".Fn rman_set_rid "struct resource *r" "int rid"
143.\".Ft int
144.\".Fn rman_get_rid "struct resource *r"
145.Sh DESCRIPTION
146The
147.Nm
148set of functions provides a flexible resource management abstraction,
149they are used extensively by the bus management code.
150It implements the abstractions of region and resource.
151A region descriptor is used to manage a region; this could be memory or
152some other form of bus space.
153.Pp
154Each region has a set of bounds.
155Within these bounds, allocated segments may reside.
156Each segment, termed a resource, has several properties which are
157represented by a 16-bit flag register, as follows.
158.Bd -literal
159#define RF_ALLOCATED    0x0001 /* resource has been reserved */
160#define RF_ACTIVE       0x0002 /* resource allocation has been activated */
161#define RF_SHAREABLE    0x0004 /* resource permits contemporaneous sharing */
162#define RF_TIMESHARE    0x0008 /* resource permits time-division sharing */
163#define RF_WANTED       0x0010 /* somebody is waiting for this resource */
164#define RF_FIRSTSHARE   0x0020 /* first in sharing list */
165#define RF_PREFETCHABLE 0x0040 /* resource is prefetchable */
166.Ed
167.Pp
168The remainder of the flag bits are used to represent the desired alignment
169of the resource within the region.
170.Pp
171The
172.Fn rman_init
173function initializes the region descriptor, pointed to by the
174.Fa rm
175argument, for use with the resource management functions.
176It also initializes any mutexes associated with the structure.
177.Pp
178The
179.Fn rman_fini
180function frees any structures associated with the structure
181pointed to by the
182.Fa rm
183argument.
184If any of the resources within the managed region have the
185.Dv RF_ALLOCATED
186flag set, it will return
187.Er EBUSY ;
188otherwise, any mutexes associated with the structure will be released
189and destroyed, and the function will return 0.
190.Pp
191The
192.Fn rman_manage_region
193function establishes the concept of a region which is under
194.Nm
195control.
196The
197.Fa rman
198argument points to the region descriptor.
199The
200.Fa start
201and
202.Fa end
203arguments specify the bounds of the region.
204.Pp
205.Em NOTE :
206This interface is not robust against programming errors which
207add multiple copies of the same region.
208.\".Pp
209.\"The
210.\".Fn rman_reserve_resource_bound
211.\"function is where the bulk of the
212.\".Nm
213.\"logic is located.
214.\"It attempts to reserve a contiguous range in the specified region
215.\".Fa rm
216.\"for the use of the device
217.\".Fa dev .
218.\"The caller can specify the
219.\".Fa start
220.\"and
221.\".Fa end
222.\"of an acceptable range, as well as
223.\"alignment, and the code will attempt to find a free segment which fits.
224.\"The default behavior is to allocate an exclusive segment, unless the
225.\".Dv RF_SHAREABLE
226.\"or
227.\".Dv RF_TIMESHARE
228.\"flags are set, in which case a shared
229.\"segment will be allocated.
230.\"If this shared segment already exists, the caller has its device
231.\"added to the list of consumers.
232.Pp
233The
234.Fn rman_reserve_resource
235function is used to reserve resources within a previously established region.
236.\"It is a simplified interface to
237.\".Fn rman_reserve_resource_bound
238.\"which passes 0 for the
239.\".Fa flags
240.\"argument.
241.Pp
242The
243.Fn rman_make_alignment_flags
244function returns the flag mask corresponding to the desired alignment
245.Fa size .
246.\"This should be used when calling
247.\".Fn rman_reserve_resource_bound .
248.Pp
249The
250.Fn rman_release_resource
251function releases the reserved resource
252.Fa r .
253It may attempt to merge adjacent free resources.
254.Pp
255The
256.Fn rman_activate_resource
257function marks a resource as active, by setting the
258.Dv RF_ACTIVE
259flag.
260If this is a time shared resource, and the caller has not yet acquired
261the resource, the function returns
262.Er EBUSY .
263.Pp
264The
265.Fn rman_deactivate_resource
266function marks a resource
267.Fa r
268as inactive, by clearing the
269.Dv RF_ACTIVE
270flag.
271If other consumers are waiting for this range, it will wakeup their threads.
272.Pp
273.\"The
274.\".Fn rman_await_resource
275.\"function performs an asynchronous wait for a resource
276.\".Fa r
277.\"to become inactive, that is, for the
278.\".Dv RF_ACTIVE
279.\"flag to be cleared.
280.\"It is used to enable cooperative sharing of a resource
281.\"which can only be safely used by one thread at a time.
282.\"The arguments
283.\".Fa pri
284.\"and
285.\".Fa timo
286.\"are passed to the
287.\".Fn rman_await_resource
288.\"function.
289.\".Pp
290The
291.Fn rman_get_start ,
292.Fn rman_get_end ,
293.Fn rman_get_size ,
294and
295.Fn rman_get_flags
296functions return the bounds, size and flags of the previously reserved
297resource
298.Fa r .
299.Pp
300The
301.Fn rman_set_bustag
302function associates a
303.Vt bus_space_tag_t
304.Fa t
305with the resource
306.Fa r .
307The
308.Fn rman_get_bustag
309function is used to retrieve this tag once set.
310.Pp
311The
312.Fn rman_set_bushandle
313function associates a
314.Vt bus_space_handle_t
315.Fa h
316with the resource
317.Fa r .
318The
319.Fn rman_get_bushandle
320function is used to retrieve this handle once set.
321.Pp
322The
323.Fn rman_set_virtual
324function is used to associate a kernel virtual address with a resource
325.Fa r .
326The
327.Fn rman_get_virtual
328function can be used to retrieve the KVA once set.
329.\".Pp
330.\"The
331.\".Fn rman_set_rid
332.\"function associates a resource identifier with a resource
333.\".Fa r .
334.\"The
335.\".Fn rman_get_rid
336.\"function retrieves this RID.
337.Pp
338The
339.Fn rman_get_device
340function returns a pointer to the device which reserved the resource
341.Fa r .
342.Sh SEE ALSO
343.\".Xr bus_activate_resource 9 ,
344.Xr bus_alloc_resource 9 ,
345.Xr bus_release_resource 9
346.\".Xr bus_set_resource 9 ,
347.Sh AUTHORS
348.An -nosplit
349This manual page was written by
350.An Bruce M Simpson Aq Mt bms@spc.org ,
351later revised by
352.An Hiten Pandya Aq Mt hmp@backplane.com .
353