linux-kernel - Re: [PATCH 07/11] cxl/mem: Trace Memory Module Event Record

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Message-ID: <Y4cipHMHN3s7EDEd@iweiny-desk3>
Date:   Wed, 30 Nov 2022 01:30:12 -0800
From:   Ira Weiny <ira.weiny@...el.com>
To:     Jonathan Cameron <Jonathan.Cameron@...wei.com>
CC:     Dan Williams <dan.j.williams@...el.com>,
        Alison Schofield <alison.schofield@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>,
        "Ben Widawsky" <bwidawsk@...nel.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Davidlohr Bueso <dave@...olabs.net>,
        <linux-kernel@...r.kernel.org>, <linux-cxl@...r.kernel.org>
Subject: Re: [PATCH 07/11] cxl/mem: Trace Memory Module Event Record

On Thu, Nov 17, 2022 at 11:22:35AM +0000, Jonathan Cameron wrote:
> On Wed, 16 Nov 2022 17:23:58 -0800
> Ira Weiny <ira.weiny@...el.com> wrote:
> 
> > On Wed, Nov 16, 2022 at 03:35:28PM +0000, Jonathan Cameron wrote:
> > > On Thu, 10 Nov 2022 10:57:54 -0800
> > > ira.weiny@...el.com wrote:
> > >   
> > > > From: Ira Weiny <ira.weiny@...el.com>
> > > > 
> > > > CXL rev 3.0 section 8.2.9.2.1.3 defines the Memory Module Event Record.
> > > > 
> > > > Determine if the event read is memory module record and if so trace the
> > > > record.
> > > > 
> > > > Signed-off-by: Ira Weiny <ira.weiny@...el.com>
> > > >   
> > > Noticed that we have a mixture of fully capitalized and not for flags.
> > > With that either explained or tidied up:
> > > 
> > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> > >   
> > > > +/*
> > > > + * Device Health Information - DHI
> > > > + *
> > > > + * CXL res 3.0 section 8.2.9.8.3.1; Table 8-100
> > > > + */
> > > > +#define CXL_DHI_HS_MAINTENANCE_NEEDED				BIT(0)
> > > > +#define CXL_DHI_HS_PERFORMANCE_DEGRADED				BIT(1)
> > > > +#define CXL_DHI_HS_HW_REPLACEMENT_NEEDED			BIT(2)
> > > > +#define show_health_status_flags(flags)	__print_flags(flags, "|",	   \
> > > > +	{ CXL_DHI_HS_MAINTENANCE_NEEDED,	"Maintenance Needed"	}, \
> > > > +	{ CXL_DHI_HS_PERFORMANCE_DEGRADED,	"Performance Degraded"	}, \
> > > > +	{ CXL_DHI_HS_HW_REPLACEMENT_NEEDED,	"Replacement Needed"	}  \  
> > > 
> > > Why are we sometime using capitals for flags (e.g patch 5) and not other times?  
> > 
> > Not sure what you mean.  Do you mean this from patch 5?
> Nope
> 
> +#define CXL_DPA_VOLATILE			BIT(0)
> +#define CXL_DPA_NOT_REPAIRABLE			BIT(1)
> +#define show_dpa_flags(flags)	__print_flags(flags, "|",		   \
> +	{ CXL_DPA_VOLATILE,			"VOLATILE"		}, \
> +	{ CXL_DPA_NOT_REPAIRABLE,		"NOT_REPAIRABLE"	}  \
> +)
> +
> 
> Where they are all capitals.  I thought that was maybe a flags vs other fields
> thing but it doesn't seem to be.

I've not made all flags capital on this and other patches.

Ira

> 
> 
> > 
> > ...
> >         { CXL_GMER_EVT_DESC_UNCORECTABLE_EVENT,         "Uncorrectable Event"   }, \
> >         { CXL_GMER_EVT_DESC_THRESHOLD_EVENT,            "Threshold event"       }, \
> >         { CXL_GMER_EVT_DESC_POISON_LIST_OVERFLOW,       "Poison List Overflow"  }  \
> > ...
> > 
> > Threshold event was a mistake.  This is the capitalization the spec uses.
> > 
> > Bit[0]: Uncorrectable Event: When set, indicates the reported event is
> >         ^^^^^^^^^^^^^^^^^^^
> > uncorrectable by the device. When cleared, indicates the reported
> > event was corrected by the device.
> > 
> > Bit[1]: Threshold Event: When set, the event is the result of a
> >         ^^^^^^^^^^^^^^^
> > threshold on the device having been reached. When cleared, the event
> > is not the result of a threshold limit.
> > 
> > Bit[2]: Poison List Overflow Event: When set, the Poison List has
> >         ^^^^^^^^^^^^^^^^^^^^^^^^^^
> > overflowed, and this event is not in the Poison List. When cleared, the
> > Poison List has not overflowed.
> > 
> > 
> > I'll update this 'Event' in patch 5.  Probably need to add 'Event' to the
> > Poison List...
> > 
> > Ira
>