bus_adjust_resource (9)

Leading comments

Copyright (c) 2011 Hudson River Trading LLC
Written by: John H. Baldwin <jhb@FreeBSD.org>
All rights reserved.

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modification, are permitted provided that the following conditions
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   notice, this list of conditions and the following disclaimer.
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   notice, this list of conditions and t...

(The comments found at the beginning of the groff file "man9/bus_adjust_resource.9freebsd".)

NAME

bus_adjust_resource - adjust resource allocated from a parent bus

SYNOPSIS

In sys/param.h In sys/bus.h

In machine/bus.h In sys/rman.h In machine/resource.h Ft int Fn bus_adjust_resource device_t dev int type struct resource *r u_long start u_long end

DESCRIPTION

This function is used to ask the parent bus to adjust the resource range assigned to an allocated resource. The resource Fa r should have been allocated by a previous call to bus_alloc_resource9. The new resource range must overlap the existing range of Fa r . The Fa type argument should match the Fa type argument passed to bus_alloc_resource9 when the resource was initially allocated.

Note that none of the constraints of the original allocation request such as alignment or boundary restrictions are checked by Fn bus_adjust_resource . It is the caller's responsibility to enforce any such requirements.

RETURN VALUES

The Fn bus_adjust_resource method returns zero on success or an error code on failure.

EXAMPLES

Grow an existing memory resource by 4096 bytes.

        struct resource *res;
        int error;

        error = bus_adjust_resource(dev, SYS_RES_MEMORY, res,
            rman_get_start(res), rman_get_end(res) + 0x1000);

ERRORS

Fn bus_adjust_resource will fail if:

Bq Er EINVAL

The Fa dev device does not have a parent device.

Bq Er EINVAL

The Fa r resource is a shared resource.

Bq Er EINVAL

The new address range does not overlap with the existing address range of Fa r .

Bq Er EBUSY

The new address range conflicts with another allocated resource.

SEE ALSO

bus_alloc_resource9, bus_release_resource9, device(9), driver(9)