> > Von: Scott Wood [scottw...@freescale.com]
> > Gesendet: Mittwoch, 28. Januar 2015 05:21
> > An: Markus Stockhausen
> > Cc: Michael Ellerman; linuxppc-dev@lists.ozlabs.org; Herbert Xu
> > Betreff: Re: SPE & Interrupt context (was how to make use of SPE
> > instructions)
> >
> > Hi Scott,
> >
> > thanks for your helpful feedback. As you might have seen I sent a first
> > patch for the sha256 kernel module that takes care about preemption.
> >
> > Herbert Xu noticed that my module won't run in for IPsec as all
> > work will be done from interrupt context. Do you have a tip how I can
> > mitigate the check I implemented:
> >
> > static bool spe_usable(void)
> > {
> > return !in_interrupt();
> > }
> >
> > Intel guys have something like that
> >
> > bool irq_fpu_usable(void)
> > {
> > return !in_interrupt() ||
> > interrupted_user_mode() ||
> > interrupted_kernel_fpu_idle();
> > }
> >
> > But I have no idea how to transfer it to the PPC/SPE case.
>
> I'm not sure what sort of tip you're looking for, other than
> implementing it myself. :-)
Hi Scott,
maybe I did not explain it correctly. interrupted_kernel_fpu_idle()
is x86 specific. The same applies to interrupted_user_mode().
I'm just searching for a similar feature in the PPC/SPE world.
I can see that enable_kernel_spe() does something with the
MSR_SPE flag, but I have no idea how to determine if I'm allowed
to enable SPE although I'm inside an interrupt context.
I'm asking because from the previous posts I conclude that
running SPE instructions inside an interrupt might be critical.
Because of registers not being saved?
Or can I just save the register contents myself and interrupt
context is no longer a showstopper?
Markus
****************************************************************************
Diese E-Mail enthält vertrauliche und/oder rechtlich geschützte
Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail
irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und
vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte
Weitergabe dieser Mail ist nicht gestattet.
Ãber das Internet versandte E-Mails können unter fremden Namen erstellt oder
manipuliert werden. Deshalb ist diese als E-Mail verschickte Nachricht keine
rechtsverbindliche Willenserklärung.
Collogia
Unternehmensberatung AG
Ubierring 11
D-50678 Köln
Vorstand:
Kadir Akin
Dr. Michael Höhnerbach
Vorsitzender des Aufsichtsrates:
Hans Kristian Langva
Registergericht: Amtsgericht Köln
Registernummer: HRB 52 497
This e-mail may contain confidential and/or privileged information. If you
are not the intended recipient (or have received this e-mail in error)
please notify the sender immediately and destroy this e-mail. Any
unauthorized copying, disclosure or distribution of the material in this
e-mail is strictly forbidden.
e-mails sent over the internet may have been written under a wrong name or
been manipulated. That is why this message sent as an e-mail is not a
legally binding declaration of intention.
Collogia
Unternehmensberatung AG
Ubierring 11
D-50678 Köln
executive board:
Kadir Akin
Dr. Michael Höhnerbach
President of the supervisory board:
Hans Kristian Langva
Registry office: district court Cologne
Register number: HRB 52 497
****************************************************************************
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
