From: Tony Lindgren <tony@atomide.com>
To: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Cc: Matthijs van Duin <matthijsvanduin@gmail.com>,
Sebastian Reichel <sre@kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
Pavel Machek <pavel@ucw.cz>
Subject: Re: ARM errata 430973 on multi platform kernels
Date: Mon, 6 Apr 2015 10:42:45 -0700 [thread overview]
Message-ID: <20150406174245.GJ18048@atomide.com> (raw)
In-Reply-To: <5522BEEF.2000405@gmail.com>
* Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> [150406 10:15]:
> On 6.04.2015 18:40, Tony Lindgren wrote:
> >
> >Oops sorry, wrong numbers for errata above.. s/458693/430973/, here's
> >a better version:
> >
> >1. For cortex-a8 revisions affected by 430973, we can do a custom
> > cpu_v7_switch_mm function that always does flush BTAC/BTB.
> >
>
> Why custom function, if IBE bit is zero, BTB invalidate instruction is a
> NOP. Do you think that "mcr p15, 0, r2, c7, c5, 6" executed as a NOP will
> put so much overhead, that it deserves a custom function?
Hmm but it still seems to do something also on cortex-a8 r3p2 that
is supposedly not affected by 430973.. Based on my tests so far, at least
armhf running cpuburn-a8 in the background and doing apt-get update
segfaults constantly without flush BTAC/BTB. This seems to be the case
no matter how the aux ctrl reg bits are set.. This should be reproducable
on any pandboard xm BTW.
> >2. For HS cortex-a8 processors other than n900 affected by 430973,
> > we need to implement functions similar to rx51_secure_update_aux_cr,
> > the bootrom on n900 is different from TI HS omaps so the SMC call
> > numbering may be different.
> >
> >3. For later cortex-a8 processors not affected by 430973, we need
> > to clear IBE bit to avoid erratum 687067.
> >
>
> Maybe it should be implemented something like:
>
> 1. if Cortex-A8, always execute invalidate BTB instruction in
> cpu_v7_switch_mm
This part still seems to need more investigating for why it's still
needed also r3p2 as I describe above. Otherwise we may be hiding some
other bug.
> 2. For Cortex-A8 revisions affected by 430973, set IBE bit to 1, set it
> to 0 for all others. That should happen as soon as possible,
> otherwise kernel may crash on affected revisions if thumb-
> compiled.
Yes this makes sense.
Regards,
Tony
WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: ARM errata 430973 on multi platform kernels
Date: Mon, 6 Apr 2015 10:42:45 -0700 [thread overview]
Message-ID: <20150406174245.GJ18048@atomide.com> (raw)
In-Reply-To: <5522BEEF.2000405@gmail.com>
* Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> [150406 10:15]:
> On 6.04.2015 18:40, Tony Lindgren wrote:
> >
> >Oops sorry, wrong numbers for errata above.. s/458693/430973/, here's
> >a better version:
> >
> >1. For cortex-a8 revisions affected by 430973, we can do a custom
> > cpu_v7_switch_mm function that always does flush BTAC/BTB.
> >
>
> Why custom function, if IBE bit is zero, BTB invalidate instruction is a
> NOP. Do you think that "mcr p15, 0, r2, c7, c5, 6" executed as a NOP will
> put so much overhead, that it deserves a custom function?
Hmm but it still seems to do something also on cortex-a8 r3p2 that
is supposedly not affected by 430973.. Based on my tests so far, at least
armhf running cpuburn-a8 in the background and doing apt-get update
segfaults constantly without flush BTAC/BTB. This seems to be the case
no matter how the aux ctrl reg bits are set.. This should be reproducable
on any pandboard xm BTW.
> >2. For HS cortex-a8 processors other than n900 affected by 430973,
> > we need to implement functions similar to rx51_secure_update_aux_cr,
> > the bootrom on n900 is different from TI HS omaps so the SMC call
> > numbering may be different.
> >
> >3. For later cortex-a8 processors not affected by 430973, we need
> > to clear IBE bit to avoid erratum 687067.
> >
>
> Maybe it should be implemented something like:
>
> 1. if Cortex-A8, always execute invalidate BTB instruction in
> cpu_v7_switch_mm
This part still seems to need more investigating for why it's still
needed also r3p2 as I describe above. Otherwise we may be hiding some
other bug.
> 2. For Cortex-A8 revisions affected by 430973, set IBE bit to 1, set it
> to 0 for all others. That should happen as soon as possible,
> otherwise kernel may crash on affected revisions if thumb-
> compiled.
Yes this makes sense.
Regards,
Tony
next prev parent reply other threads:[~2015-04-06 17:46 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-01 19:07 [PATCH RESEND] ARM: dts: OMAP3-N900: Add microphone bias voltages Jarkko Nikula
2015-03-30 16:30 ` Jarkko Nikula
[not found] ` <55197A12.1050009-FVTvWyuFUl3QT0dZR+AlfA@public.gmane.org>
2015-03-30 16:42 ` Tony Lindgren
2015-03-30 17:45 ` Jarkko Nikula
[not found] ` <55198BA4.5010207-FVTvWyuFUl3QT0dZR+AlfA@public.gmane.org>
2015-03-30 17:50 ` Tony Lindgren
2015-03-31 12:32 ` Sebastian Reichel
2015-04-01 19:47 ` Tony Lindgren
2015-04-03 16:35 ` ARM errata 430973 on multi platform kernels (was: OMAP3-N900: Add microphone bias voltages) Sebastian Reichel
2015-04-03 18:39 ` Tony Lindgren
2015-04-03 18:39 ` Tony Lindgren
2015-04-03 19:21 ` Robert Nelson
2015-04-03 19:21 ` Robert Nelson
2015-04-05 13:00 ` Sebastian Reichel
2015-04-05 13:00 ` Sebastian Reichel
2015-04-05 13:26 ` Pali Rohár
2015-04-05 13:26 ` Pali Rohár
2015-04-05 13:45 ` Sebastian Reichel
2015-04-05 13:45 ` Sebastian Reichel
2015-04-05 13:52 ` Pali Rohár
2015-04-05 13:52 ` Pali Rohár
2015-04-06 17:38 ` Sebastian Reichel
2015-04-06 17:38 ` Sebastian Reichel
2015-04-03 20:42 ` Pavel Machek
2015-04-03 20:42 ` Pavel Machek
2015-04-03 22:08 ` ARM errata 430973 on multi platform kernels Ivaylo Dimitrov
2015-04-03 22:08 ` Ivaylo Dimitrov
2015-04-03 22:15 ` Tony Lindgren
2015-04-03 22:15 ` Tony Lindgren
2015-04-03 22:47 ` Ivaylo Dimitrov
2015-04-03 22:47 ` Ivaylo Dimitrov
2015-04-03 22:52 ` Tony Lindgren
2015-04-03 22:52 ` Tony Lindgren
2015-04-05 4:13 ` Matthijs van Duin
2015-04-05 4:13 ` Matthijs van Duin
2015-04-05 7:23 ` Ivaylo Dimitrov
2015-04-05 7:23 ` Ivaylo Dimitrov
2015-04-05 16:50 ` Matthijs van Duin
2015-04-05 16:50 ` Matthijs van Duin
2015-04-05 16:52 ` Matthijs van Duin
2015-04-05 16:52 ` Matthijs van Duin
2015-04-05 21:08 ` Ivaylo Dimitrov
2015-04-05 21:08 ` Ivaylo Dimitrov
2015-04-05 23:52 ` Matthijs van Duin
2015-04-05 23:52 ` Matthijs van Duin
2015-04-06 15:19 ` Tony Lindgren
2015-04-06 15:19 ` Tony Lindgren
2015-04-06 15:40 ` Tony Lindgren
2015-04-06 15:40 ` Tony Lindgren
2015-04-06 17:14 ` Ivaylo Dimitrov
2015-04-06 17:14 ` Ivaylo Dimitrov
2015-04-06 17:42 ` Tony Lindgren [this message]
2015-04-06 17:42 ` Tony Lindgren
2015-04-06 18:14 ` Matthijs van Duin
2015-04-06 18:14 ` Matthijs van Duin
2015-04-07 2:23 ` Tony Lindgren
2015-04-07 2:23 ` Tony Lindgren
2015-04-07 3:12 ` Sebastian Reichel
2015-04-07 3:12 ` Sebastian Reichel
2015-04-07 3:49 ` Matthijs van Duin
2015-04-07 3:49 ` Matthijs van Duin
2015-04-07 14:48 ` Tony Lindgren
2015-04-07 14:48 ` Tony Lindgren
2015-04-09 22:37 ` Grazvydas Ignotas
2015-04-09 22:37 ` Grazvydas Ignotas
2015-04-09 22:44 ` Tony Lindgren
2015-04-09 22:44 ` Tony Lindgren
2015-04-09 23:44 ` Nishanth Menon
2015-04-09 23:44 ` Nishanth Menon
2015-04-10 22:05 ` Grazvydas Ignotas
2015-04-10 22:05 ` Grazvydas Ignotas
2015-04-10 23:08 ` Tony Lindgren
2015-04-10 23:08 ` Tony Lindgren
2015-04-16 16:53 ` Matthijs van Duin
2015-04-16 16:53 ` Matthijs van Duin
2015-04-07 13:58 ` Russell King - ARM Linux
2015-04-07 13:58 ` Russell King - ARM Linux
2015-04-07 13:57 ` Russell King - ARM Linux
2015-04-07 13:57 ` Russell King - ARM Linux
2015-04-07 15:22 ` Tony Lindgren
2015-04-07 15:22 ` Tony Lindgren
2015-04-07 15:44 ` Tony Lindgren
2015-04-07 15:44 ` Tony Lindgren
2015-04-08 23:08 ` Russell King - ARM Linux
2015-04-08 23:08 ` Russell King - ARM Linux
2015-04-08 23:15 ` Tony Lindgren
2015-04-08 23:15 ` Tony Lindgren
2015-04-08 23:06 ` Russell King - ARM Linux
2015-04-08 23:06 ` Russell King - ARM Linux
2015-04-09 13:48 ` Russell King - ARM Linux
2015-04-09 13:48 ` Russell King - ARM Linux
2015-04-09 15:09 ` Tony Lindgren
2015-04-09 15:09 ` Tony Lindgren
2015-04-09 15:30 ` Russell King - ARM Linux
2015-04-09 15:30 ` Russell King - ARM Linux
2015-04-15 16:31 ` Sebastian Reichel
2015-04-15 16:31 ` Sebastian Reichel
2015-04-16 16:08 ` Tony Lindgren
2015-04-16 16:08 ` Tony Lindgren
2015-04-17 18:41 ` Sebastian Reichel
2015-04-17 18:41 ` Sebastian Reichel
2015-04-20 23:40 ` Tony Lindgren
2015-04-20 23:40 ` Tony Lindgren
2015-04-23 10:25 ` Russell King - ARM Linux
2015-04-23 10:25 ` Russell King - ARM Linux
2015-04-23 14:17 ` Tony Lindgren
2015-04-23 14:17 ` Tony Lindgren
2015-04-28 18:13 ` Russell King - ARM Linux
2015-04-28 18:13 ` Russell King - ARM Linux
2015-04-29 14:40 ` Tony Lindgren
2015-04-29 14:40 ` Tony Lindgren
2015-05-04 14:24 ` Tony Lindgren
2015-05-04 14:24 ` Tony Lindgren
2015-04-24 8:54 ` Matthijs van Duin
2015-04-24 8:54 ` Matthijs van Duin
2015-04-28 18:11 ` Russell King - ARM Linux
2015-04-28 18:11 ` Russell King - ARM Linux
2015-05-02 6:51 ` Matthijs van Duin
2015-05-02 6:51 ` Matthijs van Duin
2015-04-05 13:39 ` Sebastian Reichel
2015-04-05 13:39 ` Sebastian Reichel
2015-04-06 15:24 ` Tony Lindgren
2015-04-06 15:24 ` Tony Lindgren
2015-05-04 16:07 ` [PATCH RESEND] ARM: dts: OMAP3-N900: Add microphone bias voltages Tony Lindgren
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