From: Ingo Molnar <mingo@elte.hu>
To: Robin Holt <holt@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
"H. Peter Anvin" <hpa@zytor.com>,
tglx@linutronix.de, Jack Steiner <steiner@sgi.com>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [patch 0/8] x86: UV - XPC fixes with related support functionality V2.
Date: Tue, 24 Nov 2009 08:19:31 +0100 [thread overview]
Message-ID: <20091124071931.GA4575@elte.hu> (raw)
In-Reply-To: <20091123235751.GX6671@sgi.com>
* Robin Holt <holt@sgi.com> wrote:
> > Regarding the patches - i still very much dislike how the code
> > interfaces to the 'BIOS'. The drivers/misc/sgi-xp/ code looks rather
> > messy.
> >
> > Why isnt a pure hardware interface exposed, as both hpa and me
> > suggested in the past?
>
> The information is stored on hardware (UV-Hub and RAM) outside this
> instance of hardware.
>
> The only safe way to access that hardware is via the GRU.
>
> No GRU resources are available to the BIOS.
>
> Ergo, this interface method with multiple passes is needed.
>
> If there is a better way, I am open to suggestions.
Erm, the better way is to not use the BIOS but to access those registers
that the BIOS accesses? (which is currently hidden by the BIOS)
In other words, we want to remove arch/x86/kernel/bios_uv.c and the
uv_bios_call*() APIs and replace them via clear implementations for
clear hardware abstractions. That 'bios message queue' thing is absolute
madness for example. But the type-opaque software API too.
Ingo
next prev parent reply other threads:[~2009-11-24 7:19 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-19 17:31 [patch 0/8] x86: UV - XPC fixes with related support functionality V2 Robin Holt
2009-11-19 17:31 ` [patch 1/8] x86: UV - Introduce a means to translate from gpa -> socket_paddr Robin Holt
2009-11-19 17:31 ` [patch 2/8] x86: UV - XPC needs to provide an abstraction for uv_gpa Robin Holt
2009-11-19 17:32 ` [patch 3/8] x86: UV - Introduce uv_gpa_is_mmr Robin Holt
2009-11-19 17:32 ` [patch 4/8] X86: UV - Implement a gru_read_gpa kernel function Robin Holt
2009-11-19 17:32 ` [patch 5/8] x86: UV - Update XPC to handle updated BIOS interface Robin Holt
2009-11-19 17:32 ` [patch 6/8] x86: UV - XPC NULL deref when mesq becomes empty Robin Holt
2009-11-19 17:32 ` [patch 7/8] X86: UV - xpc_make_first_contact hang due to not accepting ACTIVE state Robin Holt
2009-11-19 17:32 ` [patch 8/8] X86: UV - XPC receive message reuse triggers invalid BUG_ON() Robin Holt
2009-11-23 18:03 ` [patch 0/8] x86: UV - XPC fixes with related support functionality V2 Ingo Molnar
2009-11-23 18:10 ` Ingo Molnar
2009-11-23 23:57 ` Robin Holt
2009-11-24 7:19 ` Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2009-11-24 1:39 Robin Holt
2009-12-15 17:04 ` Robin Holt
2009-12-15 17:06 ` Robin Holt
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