RE: [EXT] Re: coresight: Add ETM4.1 support for ThunderX2

[Tanmay Vilas Kumar Jagdale <tanmay@marvell.com>]

Hi Mathieu,

> Same comment as the previous patch along with the following...
> 
> On Thu, Aug 15, 2019 at 01:53:46PM +0000, Tanmay Vilas Kumar Jagdale wrote:
> > Add ETM4.1 periperhal ID for Marvell's ThunderX2 chip.
> >
> > Signed-off-by: Tanmay Jagdale <tanmay@marvell.com>
> > ---
> >  drivers/hwtracing/coresight/coresight-etm4x.c | 2 ++
> > drivers/hwtracing/coresight/coresight-etm4x.h | 1 +
> >  2 files changed, 3 insertions(+)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c
> > b/drivers/hwtracing/coresight/coresight-etm4x.c
> > index 7bcac8896fc1..ac3bd617907b 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> > @@ -58,6 +58,7 @@ static bool etm4_arch_supported(u8 arch)
> >  	/* Mask out the minor version number */
> >  	switch (arch & 0xf0) {
> >  	case ETM_ARCH_V4:
> > +	case ETM_ARCH_V4_1:
> 
> Why add ETM_ARCH_V4_1 when the switch statement strips off the first byte?
> 
> Look at[1], someone already added support for 4.2.
> 
> [1]. 5666dfd1d8a4 coresight: etm4x: Add support to enable ETMv4.2
> 
> 
> >  		break;
> >  	default:
> >  		return false;
> > @@ -1196,6 +1197,7 @@ static const struct amba_id etm4_ids[] = {
> >  	CS_AMBA_ID(0x000bb95e),		/* Cortex-A57 */
> >  	CS_AMBA_ID(0x000bb95a),		/* Cortex-A72 */
> >  	CS_AMBA_ID(0x000bb959),		/* Cortex-A73 */
> > +	CS_AMBA_ID(0x000cc0af),		/* Marvell ThunderX2 */
> 
> I suspect this processor also has "coresight-cpu-debug" IPs.  If that is the
> case it is very possible they both have the same CID and a UCI (see next line)
> is required.
>
Yes, our processor has the coresight-cpu-debug IP. Currently I am working with
the hardware team to test this feature. Once that is done I will post a patch
that supports it. In the meantime I will post a v2 patch for ETMv4 with UCI.
Hope that is okay.
 
> >  	CS_AMBA_UCI_ID(0x000bb9da, uci_id_etm4),	/* Cortex-A35 */
> >  	{},
> >  };
> 
> Thanks,
> Mathieu
> 
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h
> > b/drivers/hwtracing/coresight/coresight-etm4x.h
> > index 4523f10ddd0f..03369e56b2eb 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> > @@ -137,6 +137,7 @@
> >  #define ETM_MAX_SS_CMP			8
> >
> >  #define ETM_ARCH_V4			0x40
> > +#define ETM_ARCH_V4_1			0x41
> >  #define ETMv4_SYNC_MASK			0x1F
> >  #define ETM_CYC_THRESHOLD_MASK		0xFFF
> >  #define ETM_CYC_THRESHOLD_DEFAULT       0x100
> > --
> > 2.17.1
> >

Thanks,
Tanmay

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