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Date:      Thu, 1 Jun 2000 14:47:03 +0200
From:      Alexander Langer <alex@big.endian.de>
To:        FreeBSD-GNATS-submit@freebsd.org
Cc:        freebsd-doc@FreeBSD.ORG
Subject:   Re: docs/18918: add bus_alloc_resource.9 and bus_release_resource.9
Message-ID:  <20000601144703.A8285@cichlids.cichlids.com>
In-Reply-To: <200005311510.IAA34279@freefall.freebsd.org>; from phantom@cris.crimea.ua on Wed, May 31, 2000 at 08:10:02AM -0700
References:  <200005311510.IAA34279@freefall.freebsd.org>

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Too keep the new versions in the GNATS-db, here they are:

.\" -*- nroff -*-
.\"
.\" Copyright (c) 2000 Alexander Langer
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd May 18, 2000
.Dt BUS_ALLOC_RESOURCE 9
.Os FreeBSD
.Sh NAME
.Nm bus_alloc_resource
.Nd alloc resources on a bus
.Sh SYNOPSIS
.Fd #include <sys/param.h>
.Fd #include <sys/bus.h>
.Fd #include <sys/rman.h>
.Fd #include <sys/resource.h>
.Ft struct resource *
.Fn bus_alloc_resource "device_t dev" "int type" "int *rid" "u_long start" "u_long end" "u_long count" "u_int flags"
.Sh DESCRIPTION
.Pp
This is an easy interface to the resource-management functions.
It hides the indirection through the parent's method table. 
This function generally should be called in attach, but (except in some
race cases) never earlier.
.Pp
Its arguments are as follows:
.Bl -item
.It
.Fa dev
is the device that requests ownership of the resource.
Before allocation, the device is owned by the parent bus.
.It
.Fa type
is the type of resource you want to allocate.
It is one of:
.Bl -tag -width SYS_RES_MEMORY
.It Dv SYS_RES_IRQ
for IRQs
.It Dv SYS_RES_DRQ
for ISA DMA lines
.It Dv SYS_RES_IOPORT
for I/O ports
.It Dv SYS_RES_MEMORY
for I/O memory
.El
.It
.Fa rid
points to a bus specific handle that identifies the resource being allocated.
For ISA this is an index into an array of resources that have been setup
for this device by either the PnP mechanism, or via the hints mechanism.
For PCCARD, similar things are used as of writing,
but that may change in the future with newcard.
For PCI it just happens to be the offset into pci config space which has
a word that describes the resource.
The bus methods are free to change the RIDs that are passed to it -
that's why it is a pointer.
You must not depend on the value you gave it earlier.
.It
.Fa start
and
.Fa end
are the start/end addresses of the resource.
If you specify values of
.Dv 0
for start and
.Dv ~0
for end, the default values for the bus are calculated.
.It
.Fa count
is the size of the resource, e.g. the size of an I/O port (often
.Dv 1
on PCI and device-dependent on ISA and PCCARD). If you specified the default
values for
.Fa start
and
.Fa end ,
then the default value of the bus is used if 
.Fa count
is smaller than the default value and
.Fa count
is used, if it is bigger as the default value.
.It
.Fa flags
sets the flags for the resource. You can set one or more of these flags:
.Bl -tag -width RF_SHAREABLE
.It Dv RF_ALLOCATED
resource has been reserved.
Resource still needs to be activated with
.Xr rman_activate_resource 9 .
.It Dv RF_ACTIVE
activate resource atomically.
.It Dv RF_SHAREABLE
resource permits contemporaneous sharing.
Should always be set unless you know, that the resource cannot be shared.
It is the bus-code's task to filter out the flag if the bus doesn't
support sharing, which is, for example, the case for pccard/cardbus,
which can or can not share devices, depending on the bus.
.It Dv RF_TIMESHARE
resource permits time-division sharing.
.El
.El
.Sh RETURN VALUES
A pointer to
.Va struct res
is returned on success, a null pointer otherwise.
.Sh EXAMPLES
This is some example code. The values of
.Va portid
and
.Va irqid
should be saved in the softc of the device after these calls.
.Bd -literal
	struct resource *portres, irqres;
	int portid, irqid;

	portid = 0;
	irqid = 0;
	portres = bus_alloc_resource(dev, SYS_RES_IOPORT, &portid, 
			0ul, ~0ul, 32, RF_ACTIVE);
	irqres = bus_alloc_resource(dev, SYS_RES_IRQ, &irqid, 
			0ul, ~0ul, 1, RF_ACTIVE | RF_SHAREABLE);
.Ed
.Sh SEE ALSO
.Xr driver 9 ,
.Xr device 9 ,
.Xr bus_release_resource 9
.Sh AUTHORS
This man page was written by
.An Alexander Langer Aq alex@big.endian.de
with parts by
.An Warner Losh Aq imp@FreeBSD.ORG .




.\" -*- nroff -*-
.\"
.\" Copyright (c) 2000 Alexander Langer
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd May 18, 2000
.Dt BUS_RELEASE_RESOURCE 9
.Os FreeBSD
.Sh NAME
.Nm bus_release_resource
.Nd release resources on a bus
.Sh SYNOPSIS
.Fd #include <sys/param.h>
.Fd #include <sys/bus.h>
.Fd #include <sys/rman.h>
.Fd #include <sys/resource.h>
.Ft int
.Fn bus_release_resource "device_t dev" "int type" "int rid" "struct resource *r"
.Sh DESCRIPTION
Free a resource allocated by
.Xr bus_alloc_resource 9 .
The resource must not be in use on release, i.e. call an appropriate function
before (e.g.
.Xr bus_teardown_intr 9
for IRQs).
.Bl -item
.It
.Fa dev
is the device that owns the resource.
.It
.Fa type
is the type of resource that is released.
It must be of the same type you allocated it as before.
See
.Xr bus_alloc_resource 9
for valid types.
.It
.Fa rid
is the resource ID of the resource.
The
.Fa rid
value must be the same as the one returned by
.Xr bus_alloc_resource 9 .
.It
.Fa r
is the pointer to
.Va struct res ,
i.e. the resource itself,
returned by
.Xr bus_alloc_resource 9 .
.El
.Sh RETURN VALUES
.Er EINVAL
is returned, if the device
.Fa dev
has no parent,
.Dv 0
otherwise.
The kernel will panic, if it can't release the resource.
.Sh EXAMPLES
.Bd -literal
	/* deactivate IRQ */
	bus_teardown_intr(dev, foosoftc->irqres, foosoftc->irqid);  

	/* release IRQ resource */
	bus_release_resource(dev, SYS_RES_IRQ, foosoftc->irqid,
		foosoftc->irqres);

	/* release I/O port resource */
	bus_release_resource(dev, SYS_RES_IOPORT, foosoftc->portid,
		foosoftc->portres);
.Ed
.Sh SEE ALSO
.Xr driver 9 ,
.Xr device 9 ,
.Xr bus_alloc_resource 9
.Sh AUTHORS
This man page was written by
.An Alexander Langer Aq alex@big.endian.de .


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