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 March 15, 2005 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 191.Fa start 192argument is the lowest acceptable starting value of the resource. 193The 194.Fa end 195argument is the highest acceptable ending value of the resource. 196Therefore, 197.Fa start No + Fa count No \- 1 198must be \[<=] 199.Fa end 200for any allocation to happen. 201The default behavior is to allocate an exclusive segment, unless the 202.Dv RF_SHAREABLE 203or 204.Dv RF_TIMESHARE 205flags are set, in which case a shared 206segment will be allocated. 207If this shared segment already exists, the caller has its device 208added to the list of consumers. 209.Pp 210The 211.Fn rman_reserve_resource 212function is used to reserve resources within a previously established region. 213It is a simplified interface to 214.Fn rman_reserve_resource_bound 215which passes 0 for the 216.Fa flags 217argument. 218.Pp 219The 220.Fn rman_make_alignment_flags 221function returns the flag mask corresponding to the desired alignment 222.Fa size . 223This should be used when calling 224.Fn rman_reserve_resource_bound . 225.Pp 226The 227.Fn rman_release_resource 228function releases the reserved resource 229.Fa r . 230It may attempt to merge adjacent free resources. 231.Pp 232The 233.Fn rman_activate_resource 234function marks a resource as active, by setting the 235.Dv RF_ACTIVE 236flag. 237If this is a time shared resource, and the caller has not yet acquired 238the resource, the function returns 239.Er EBUSY . 240.Pp 241The 242.Fn rman_deactivate_resource 243function marks a resource 244.Fa r 245as inactive, by clearing the 246.Dv RF_ACTIVE 247flag. 248If other consumers are waiting for this range, it will wakeup their threads. 249.Pp 250The 251.Fn rman_await_resource 252function performs an asynchronous wait for a resource 253.Fa r 254to become inactive, that is, for the 255.Dv RF_ACTIVE 256flag to be cleared. 257It is used to enable cooperative sharing of a resource 258which can only be safely used by one thread at a time. 259The arguments 260.Fa pri 261and 262.Fa timo 263are passed to the 264.Fn rman_await_resource 265function. 266.Pp 267The 268.Fn rman_get_start , 269.Fn rman_get_end , 270.Fn rman_get_size , 271and 272.Fn rman_get_flags 273functions return the bounds, size and flags of the previously reserved 274resource 275.Fa r . 276.Pp 277The 278.Fn rman_set_bustag 279function associates a 280.Vt bus_space_tag_t 281.Fa t 282with the resource 283.Fa r . 284The 285.Fn rman_get_bustag 286function is used to retrieve this tag once set. 287.Pp 288The 289.Fn rman_set_bushandle 290function associates a 291.Vt bus_space_handle_t 292.Fa h 293with the resource 294.Fa r . 295The 296.Fn rman_get_bushandle 297function is used to retrieve this handle once set. 298.Pp 299The 300.Fn rman_set_virtual 301function is used to associate a kernel virtual address with a resource 302.Fa r . 303The 304.Fn rman_get_virtual 305function can be used to retrieve the KVA once set. 306.Pp 307The 308.Fn rman_set_rid 309function associates a resource identifier with a resource 310.Fa r . 311The 312.Fn rman_get_rid 313function retrieves this RID. 314.Pp 315The 316.Fn rman_get_device 317function returns a pointer to the device which reserved the resource 318.Fa r . 319.Sh SEE ALSO 320.Xr bus_activate_resource 9 , 321.Xr bus_alloc_resource 9 , 322.Xr bus_release_resource 9 , 323.Xr bus_set_resource 9 , 324.Xr mutex 9 325.Sh AUTHORS 326This manual page was written by 327.An Bruce M Simpson Aq bms@spc.org . 328