svn commit: r295755 - in head/sys: arm/arm arm64/arm64 kern powerpc/powerpc sparc64/sparc64 sys

[John Baldwin]

On Thursday, February 18, 2016 01:00:04 PM Zbigniew Bodek wrote:
> Author: zbb
> Date: Thu Feb 18 13:00:04 2016
> New Revision: 295755
> URL: https://svnweb.freebsd.org/changeset/base/295755
> 
> Log:
>   Introduce bus_get_bus_tag() method
>   
>   Provide bus_get_bus_tag() for sparc64, powerpc, arm, arm64 and mips
>   nexus and its children in order to return a platform specific default tag.
>   
>   This is required to ensure generic correctness of the bus_space tag.
>   It is especially needed for arches where child bus tag does not match
>   the parent bus tag. This solves the problem with ppc architecture
>   where the PCI bus tag differs from parent bus tag which is big-endian.
>   
>   This commit is a part of the following patch:
>   https://reviews.freebsd.org/D4879
>   
>   Submitted by:  Marcin Mazurek <mma at semihalf.com>
>   Obtained from: Semihalf
>   Sponsored by:  Annapurna Labs
>   Reviewed by:   jhibbits, mmel
>   Differential Revision: https://reviews.freebsd.org/D4879

It should be noted that this API is temporary.  It should probably be marked
as such so that no code depends on it long term.  Once bus_map_resource
is implemented in the parent drivers for this bus this should be removed.
I hope to have that in place for 11 so that no release ships with this API.

I have a review open on a prototype for bus_map_resource() in D5237.

-- 
John Baldwin