1.\" 2.\" Copyright (c) 2003 Bruce M Simpson <bms@spc.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd May 12, 2003 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 112The 113.Nm 114set of functions provides a flexible resource management abstraction. 115It is used extensively by the bus management code. 116It implements the abstractions of region and resource. 117A region descriptor is used to manage a region; this could be memory or 118some other form of bus space. 119.Pp 120Each region has a set of bounds. 121Within these bounds, allocated segments may reside. 122Each segment, termed a resource, has several properties which are 123represented 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 134The remainder of the flag bits are used to represent the desired alignment 135of the resource within the region. 136.Pp 137The 138.Fn rman_init 139function initializes the region descriptor, pointed to by the 140.Fa rm 141argument, for use with the resource management functions. 142It also initializes any mutexes associated with the structure. 143.Pp 144The 145.Fn rman_fini 146function frees any structures associated with the structure 147pointed to by the 148.Fa rm 149argument. 150If any of the resources within the managed region have the 151.Dv RF_ALLOCATED 152flag set, it will return 153.Er EBUSY ; 154otherwise, any mutexes associated with the structure will be released 155and destroyed, and the function will return 0. 156.Pp 157The 158.Fn rman_manage_region 159function establishes the concept of a region which is under 160.Nm 161control. 162The 163.Fa rman 164argument points to the region descriptor. 165The 166.Fa start 167and 168.Fa end 169arguments specify the bounds of the region. 170.Pp 171.Em NOTE : 172This interface is not robust against programming errors which 173add multiple copies of the same region. 174.Pp 175The 176.Fn rman_reserve_resource_bound 177function is where the bulk of the 178.Nm 179logic is located. 180It attempts to reserve a contiguous range in the specified region 181.Fa rm 182for the use of the device 183.Fa dev . 184The caller can specify the 185.Fa start 186and 187.Fa end 188of an acceptable range, as well as 189alignment, and the code will attempt to find a free segment which fits. 190The default behavior is to allocate an exclusive segment, unless the 191.Dv RF_SHAREABLE 192or 193.Dv RF_TIMESHARE 194flags are set, in which case a shared 195segment will be allocated. 196If this shared segment already exists, the caller has its device 197added to the list of consumers. 198.Pp 199The 200.Fn rman_reserve_resource 201function is used to reserve resources within a previously established region. 202It is a simplified interface to 203.Fn rman_reserve_resource_bound 204which passes 0 for the 205.Fa flags 206argument. 207.Pp 208The 209.Fn rman_make_alignment_flags 210function returns the flag mask corresponding to the desired alignment 211.Fa size . 212This should be used when calling 213.Fn rman_reserve_resource_bound . 214.Pp 215The 216.Fn rman_release_resource 217function releases the reserved resource 218.Fa r . 219It may attempt to merge adjacent free resources. 220.Pp 221The 222.Fn rman_activate_resource 223function marks a resource as active, by setting the 224.Dv RF_ACTIVE 225flag. 226If this is a time shared resource, and the caller has not yet acquired 227the resource, the function returns 228.Er EBUSY . 229.Pp 230The 231.Fn rman_deactivate_resource 232function marks a resource 233.Fa r 234as inactive, by clearing the 235.Dv RF_ACTIVE 236flag. 237If other consumers are waiting for this range, it will wakeup their threads. 238.Pp 239The 240.Fn rman_await_resource 241function performs an asynchronous wait for a resource 242.Fa r 243to become inactive, that is, for the 244.Dv RF_ACTIVE 245flag to be cleared. 246It is used to enable cooperative sharing of a resource 247which can only be safely used by one thread at a time. 248The arguments 249.Fa pri 250and 251.Fa timo 252are passed to the 253.Fn rman_await_resource 254function. 255.Pp 256The 257.Fn rman_get_start , 258.Fn rman_get_end , 259.Fn rman_get_size , 260and 261.Fn rman_get_flags 262functions return the bounds, size and flags of the previously reserved 263resource 264.Fa r . 265.Pp 266The 267.Fn rman_set_bustag 268function associates a 269.Vt bus_space_tag_t 270.Fa t 271with the resource 272.Fa r . 273The 274.Fn rman_get_bustag 275function is used to retrieve this tag once set. 276.Pp 277The 278.Fn rman_set_bushandle 279function associates a 280.Vt bus_space_handle_t 281.Fa h 282with the resource 283.Fa r . 284The 285.Fn rman_get_bushandle 286function is used to retrieve this handle once set. 287.Pp 288The 289.Fn rman_set_virtual 290function is used to associate a kernel virtual address with a resource 291.Fa r . 292The 293.Fn rman_get_virtual 294function can be used to retrieve the KVA once set. 295.Pp 296The 297.Fn rman_set_rid 298function associates a resource identifier with a resource 299.Fa r . 300The 301.Fn rman_get_rid 302function retrieves this RID. 303.Pp 304The 305.Fn rman_get_device 306function returns a pointer to the device which reserved the resource 307.Fa r . 308.Pp 309.Sh SEE ALSO 310.Xr bus_activate_resource 9 , 311.Xr bus_alloc_resource 9 , 312.Xr bus_release_resource 9 , 313.Xr bus_set_resource 9 , 314.Xr mutex 9 315.Sh AUTHORS 316This man page was written by 317.An Bruce M Simpson Aq bms@spc.org . 318