Re: [PATCH] ARMv7 Oprofile support

[Jean Pihet <jpihet@xxxxxxxxxx>]

Hi Xinyu,

> I have a question about ARMv6/v7 PMNC unit support.
> Why there's no DBGEN or SPNIDEN bit settings in oprofile driver?
Since there is no security framework in place from OMAP3 those bits are left 
untouched, so we are using the default values after boot. 
On the boards I have, OMAP3 is running in non secure mode (bit 18 of DSCR is 
1).

I do not think it is a good think to change those security related bits in the 
Oprofile code.

AFAIK all events are generated and processed by Oprofile.

> Without these security enable bit, PMNC will not count for L1 events.
Why would it be L1 events only? I think no event should be generated at all.

> One note from ARM1176 TRM below:
>
> 1. In Debug state the counter is disabled.
> 2. When the core is in a mode where noninvasive debug is not
> permitted, set by SPNIDEN and the SUNIDEN bit, see c1, Secure Debug
> Enable Register, the processor does not count events.
>
> Best Regards
> Xinyu
>
> 2008/7/1 Jean Pihet <jpihet@xxxxxxxxxx>
>
> > Hi,
> >
> > This patch adds Oprofile support on ARMv7, using the PMNC unit.
> > Tested on OMAP3430 SDP and 3530 EVM.
> >
> > Feedback and comments are welcome.
> >
> > The patch to user space components will be sent asap to Oprofile
> > maintainers at http://sourceforge.net/projects/oprofile/.
> >
> > Regards,
> > Jean.
> >

-------------------------------------------------------------------
List admin: http://lists.arm.linux.org.uk/mailman/listinfo/linux-arm-kernel
FAQ:        http://www.arm.linux.org.uk/mailinglists/faq.php
Etiquette:  http://www.arm.linux.org.uk/mailinglists/etiquette.php