From: David Gibson <david@gibson•dropbear.id.au>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: Alexey Kardashevskiy <aik@ozlabs•ru>,
Paul Mackerras <paulus@samba•org>,
linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH] powerpc-powernv: added tce_get callback for powernv platform
Date: Wed, 5 Sep 2012 08:35:47 +1000 [thread overview]
Message-ID: <20120904223547.GD12554@truffula.fritz.box> (raw)
In-Reply-To: <1346787702.3025.7.camel@pasglop>
On Wed, Sep 05, 2012 at 05:41:42AM +1000, Benjamin Herrenschmidt wrote:
> On Tue, 2012-09-04 at 17:35 +1000, Alexey Kardashevskiy wrote:
> > The upcoming VFIO support requires a way to know which
> > entry in the TCE map is not empty in order to do cleanup
> > at QEMU exit/crash. This patch adds such functionality
> > to POWERNV platform code.
> >
> > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs•ru>
> > ---
> > arch/powerpc/platforms/powernv/pci.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
> > index be3cfc5..61f8068 100644
> > --- a/arch/powerpc/platforms/powernv/pci.c
> > +++ b/arch/powerpc/platforms/powernv/pci.c
> > @@ -447,6 +447,11 @@ static void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
> > pnv_tce_invalidate(tbl, tces, tcep - 1);
> > }
> >
> > +static unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
> > +{
> > + return ((u64 *)tbl->it_base)[index - tbl->it_offset] & IOMMU_PAGE_MASK;
> > +}
>
> Why the masking here ?
Yes. Especially since you're masking out the permission bits which
are actually the ones you want to determine if a TCE is empty or not.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
next prev parent reply other threads:[~2012-09-04 22:35 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120821113534.GS29724@truffula.fritz.box>
2012-09-04 7:33 ` [PATCH] vfio: enabled and supported on power (v7) Alexey Kardashevskiy
2012-09-04 7:35 ` [PATCH] powerpc-powernv: added tce_get callback for powernv platform Alexey Kardashevskiy
2012-09-04 19:41 ` Benjamin Herrenschmidt
2012-09-04 22:35 ` David Gibson [this message]
2012-09-05 0:19 ` Alexey Kardashevskiy
2012-09-05 0:32 ` Benjamin Herrenschmidt
2012-09-04 7:36 ` [PATCH] powerpc-kvm: fixing page alignment for TCE Alexey Kardashevskiy
2012-09-20 9:01 ` Alexander Graf
2012-09-04 7:36 ` [PATCH] powerpc-powernv: align BARs to PAGE_SIZE on powernv platform Alexey Kardashevskiy
2012-09-04 19:45 ` Benjamin Herrenschmidt
2012-09-05 0:55 ` Alexey Kardashevskiy
2012-09-05 1:16 ` Benjamin Herrenschmidt
2012-09-05 4:57 ` Alex Williamson
2012-09-05 5:17 ` Benjamin Herrenschmidt
2012-09-05 5:27 ` Alexey Kardashevskiy
2012-09-10 17:06 ` Alex Williamson
2012-09-10 16:02 ` [PATCH] vfio: enabled and supported on power (v7) Alex Williamson
2012-09-11 8:28 ` Alexey Kardashevskiy
2012-09-13 22:34 ` Alex Williamson
2012-09-13 22:41 ` Scott Wood
2012-09-13 22:55 ` Alex Williamson
2012-09-14 0:51 ` Alexey Kardashevskiy
2012-09-14 4:35 ` Alex Williamson
2012-10-11 8:19 ` Alexey Kardashevskiy
2012-10-11 18:09 ` Alex Williamson
2012-09-05 1:19 [PATCH] powerpc-powernv: added tce_get callback for powernv platform Alexey Kardashevskiy
2012-09-10 2:35 ` David Gibson
2012-09-10 5:19 ` Benjamin Herrenschmidt
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