Messages in this thread | | | Date | Thu, 8 Sep 2011 17:50:44 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] UV2 - Bug fix for GRU global addresses |
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On Thu, 8 Sep 2011 19:29:16 -0500 Jack Steiner <steiner@sgi.com> wrote:
> On Thu, Sep 08, 2011 at 04:51:39PM -0700, Andrew Morton wrote: > > (cc x86 maintainers) > > > > On Thu, 8 Sep 2011 13:24:13 -0500 > > Jack Steiner <steiner@sgi.com> wrote: > > > > > This patch is a workaround for a UV2 hub bug that affects the format > > > of system global addresses. > > > > > > The GRU API for UV2 was inadvertently broken by a hardware change. The > > > format of the physical address used for TLB dropins and for addresses used > > > with instructions running in unmapped mode has changed. This change was not > > > documented and became apparent only when diags failed running on system simulators. > > > > > > For UV1, TLB and GRU instruction physical addresses are identical to socket > > > physical addresses (although high NASID bits must be OR'ed into the > > > address). > > > > > > For UV2, socket physical addresses need to be converted. The NODE portion of > > > the physical address needs to be shifted so that the low bit is in bit 39 or > > > bit 40, depending on an MMR value. > > > > > > It is not yet clear if this bug will be fixed in a silicon respin. If it > > > is fixed, the hub revision will be incremented & the workaround disabled. > > > > It's unclear to me whether this patch should be merged into 3.1 and/or > > into 3.0.x and earlier? > > 3.1 is fine. I can push directly to the distros.
Don't do that. It's better for a pile of reasons for this to come via kernel.org.
Again, what is the case for backporting?
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