Re: [PATCH v3 4/6] cxl/region: Add trigger_poison_list sysfs attribute

[Alison Schofield]

On Wed, Nov 16, 2022 at 12:50:38PM +0000, Jonathan Cameron wrote:
> On Thu, 10 Nov 2022 19:12:42 -0800
> alison.schofield@xxxxxxxxx wrote:
> 
> > From: Alison Schofield <alison.schofield@xxxxxxxxx>
> > 
> > When a boolean 'true' is written to this attribute the region driver
> > retrieves the poison list for the capacity each device contributes
> > to this region. The list includes addresses that are poisoned, or
> > would result in poison if accessed, and the source of the poison.
> > The retrieved errors are logged as kernel trace events with the
> > label 'cxl_poison'.
> > 
> > Devices not supporting the poison list capability are ignored.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx>
> Trivial comment inline you might want to consider.

Thanks, got it!  I will 'include' your tag going forward.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> 
> > ---
> >  Documentation/ABI/testing/sysfs-bus-cxl | 14 +++++++++++
> >  drivers/cxl/core/region.c               | 33 +++++++++++++++++++++++++
> >  2 files changed, 47 insertions(+)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > index 1c5f4a853ba2..54fad3bdcb2b 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > @@ -402,3 +402,17 @@ Description:
> >  		attribute is only visible for devices supporting the
> >  		capability. The retrieved errors are logged as kernel
> >  		trace events with the label 'cxl_poison'.
> > +
> > +
> > +What:		/sys/bus/cxl/devices/regionZ/trigger_poison_list
> > +Date:		November, 2022
> > +KernelVersion:	v6.2
> > +Contact:	linux-cxl@xxxxxxxxxxxxxxx
> > +Description:
> > +		(WO) When a boolean 'true' is written to this attribute the
> > +		region driver retrieves the poison list for the capacity
> > +		each device contributes to this region. The list includes
> Trivial: Same as in previous patch. "includes" is too vague.
> 
> > +		addresses that are poisoned, or would result in poison if
> > +		accessed, and the source of the poison. The retrieved
> > +		errors are logged as kernel trace events with the label
> > +		'cxl_poison'.
> > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> > index f9ae5ad284ff..68821238491e 100644
> > --- a/drivers/cxl/core/region.c
> > +++ b/drivers/cxl/core/region.c
> > @@ -72,6 +72,38 @@ static int is_dup(struct device *match, void *data)
> >  	return 0;
> >  }
> >  
> > +static ssize_t trigger_poison_list_store(struct device *dev,
> > +					 struct device_attribute *attr,
> > +					 const char *buf, size_t len)
> > +{
> > +	struct cxl_region *cxlr = to_cxl_region(dev);
> > +	struct cxl_region_params *p = &cxlr->params;
> > +	struct cxl_endpoint_decoder *cxled;
> > +	struct cxl_memdev *cxlmd;
> > +	u64 offset, length;
> > +	int rc, i;
> > +	bool tmp;
> > +
> > +	if (kstrtobool(buf, &tmp))
> > +		return -EINVAL;
> > +
> > +	for (i = 0; i <  p->nr_targets; i++) {
> > +		cxled = p->targets[i];
> > +		cxlmd = cxled_to_memdev(cxled);
> > +		if (!test_bit(CXL_MEM_COMMAND_ID_GET_POISON,
> > +			      cxlmd->cxlds->enabled_cmds))
> > +			continue;
> > +
> > +		offset = cxl_dpa_resource_start(cxled);
> > +		length = cxl_dpa_size(cxled);
> > +		rc = cxl_mem_get_poison(cxlmd, offset, length, cxlr);
> > +		if (rc)
> > +			return rc;
> > +	}
> > +	return len;
> > +}
> > +static DEVICE_ATTR_WO(trigger_poison_list);
> > +
> >  static ssize_t uuid_store(struct device *dev, struct device_attribute *attr,
> >  			  const char *buf, size_t len)
> >  {
> > @@ -570,6 +602,7 @@ static struct attribute *cxl_region_attrs[] = {
> >  	&dev_attr_interleave_granularity.attr,
> >  	&dev_attr_resource.attr,
> >  	&dev_attr_size.attr,
> > +	&dev_attr_trigger_poison_list.attr,
> >  	NULL,
> >  };
> >  
>