Date: Wed, 9 Oct 2013 14:46:16 -0600 From: Warner Losh <imp@bsdimp.com> To: Adrian Chadd <adrian@FreeBSD.org> Cc: "freebsd-mips@freebsd.org" <freebsd-mips@freebsd.org> Subject: Re: [rfc] implement busdma barrier operation Message-ID: <0ABAE1CE-C4C3-4A3E-843E-E9B450559012@bsdimp.com> In-Reply-To: <CAJ-Vmo=Vyz_QzSki=rV5WX1LxCma7w=52rKOQ6JVsy0zQTRjbg@mail.gmail.com> References: <CAJ-Vmo=Vyz_QzSki=rV5WX1LxCma7w=52rKOQ6JVsy0zQTRjbg@mail.gmail.com>
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On Oct 8, 2013, at 6:33 PM, Adrian Chadd wrote: >=20 > I'd like to implement the busdma barrier operation. You'd like to improve the bus space read and write barrier = implementation on MIPS. > This is required for > (at least) correct behaviour of devices on the ar9344 (mips74k) core, = as > now I actually need to care about the order of device operations. Yup. We should have had something like this all along. You can get rid, I think, of the cache invalidation and write back too, = since that's such a huge hit we'll never do that in a generic = implementation. The rest of the change looks good to me. Warner > This (and some local uncommitted changes) are required for the ar9344 > ethernet and switchport devices to correctly function. >=20 > I've tested this on the other mips24k hardware I have and it works. = But > nothing else (including ath, grr) explicitly uses read/write barriers. = I'll > eventually add them. >=20 > I'd like to bounce this to re@ ASAP to get the approval to commit. >=20 > Thanks, >=20 >=20 > -adrian >=20 >=20 > Index: sys/mips/mips/bus_space_generic.c > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > --- sys/mips/mips/bus_space_generic.c (revision 256173) > +++ sys/mips/mips/bus_space_generic.c (working copy) > @@ -749,4 +749,8 @@ > if (flags & BUS_SPACE_BARRIER_WRITE) > mips_dcache_wbinv_all(); > #endif > + if (flags & BUS_SPACE_BARRIER_READ) > + rmb(); > + if (flags & BUS_SPACE_BARRIER_WRITE) > + wmb(); > } > _______________________________________________ > freebsd-mips@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-mips > To unsubscribe, send any mail to = "freebsd-mips-unsubscribe@freebsd.org"
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