Re: [PATCH V3 4/8] cxl/mem: Trace DRAM Event Record

[Ira Weiny <ira.weiny@intel.com>]

On Fri, Dec 09, 2022 at 02:14:41PM -0800, Dan Williams wrote:
> ira.weiny@ wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> > 
> > CXL rev 3.0 section 8.2.9.2.1.2 defines the DRAM Event Record.
> > 
> > Determine if the event read is a DRAM event record and if so trace the
> > record.
> > 
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > 
> > ---
> > Changes from v2:
> > 	Dan
> > 		Move tracing to cxl core
> > 		Remove trace_*_enabled() calls
> > 		Pass struct device to trace points
> > 
> > Changes from RFC v2:
> > 	Output DPA flags as a separate field.
> > 	Ensure field names match TP_print output
> > 	Steven
> > 		prefix TRACE_EVENT with 'cxl_'
> > 	Jonathan
> > 		Formatting fix
> > 		Remove reserved field
> > 
> > Changes from RFC:
> > 	Add reserved byte data
> > 	Use new CXL header macros
> > 	Jonathan
> > 		Use get_unaligned_le{24,16}() for unaligned fields
> > 		Use 'else if'
> > 	Dave Jiang
> > 		s/cxl_dram_event/dram
> > 		s/cxl_evt_dram_rec/cxl_event_dram
> > 	Adjust for new phys addr mask
> > ---
> >  drivers/cxl/core/mbox.c  | 13 ++++++
> >  drivers/cxl/core/trace.h | 92 ++++++++++++++++++++++++++++++++++++++++
> >  drivers/cxl/cxlmem.h     | 23 ++++++++++
> >  3 files changed, 128 insertions(+)
> > 
> > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> > index 0d8c66f1cdc5..2fa4645f0ed9 100644
> > --- a/drivers/cxl/core/mbox.c
> > +++ b/drivers/cxl/core/mbox.c
> > @@ -726,6 +726,14 @@ static const uuid_t gen_media_event_uuid =
> >  	UUID_INIT(0xfbcd0a77, 0xc260, 0x417f,
> >  		  0x85, 0xa9, 0x08, 0x8b, 0x16, 0x21, 0xeb, 0xa6);
> >  
> > +/*
> > + * DRAM Event Record
> > + * CXL rev 3.0 section 8.2.9.2.1.2; Table 8-44
> > + */
> > +static const uuid_t dram_event_uuid =
> > +	UUID_INIT(0x601dcbb3, 0x9c06, 0x4eab,
> > +		  0xb8, 0xaf, 0x4e, 0x9b, 0xfb, 0x5c, 0x96, 0x24);
> > +
> >  static void cxl_trace_event_record(const struct device *dev,
> >  				   enum cxl_event_log_type type,
> >  				   struct cxl_event_record_raw *record)
> > @@ -738,6 +746,11 @@ static void cxl_trace_event_record(const struct device *dev,
> >  
> >  		trace_cxl_general_media(dev, type, rec);
> >  		return;
> > +	} else if (uuid_equal(id, &dram_event_uuid)) {
> > +		struct cxl_event_dram *rec = (struct cxl_event_dram *)record;
> > +
> > +		trace_cxl_dram(dev, type, rec);
> > +		return;
> 
> I think I mentioned this before,

Sorry, I don't remember seeing that.

>
> but rather than a "return" in every
> branch just make the 'unknown' case the final else in this if block.

Sounds good.  However the previous patch started this pattern so I fixed it
there and continued through these.

> 
> With that feel free to add:
> 
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>

Thanks!
Ira