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

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Thu, 10 Nov 2022 19:12:42 -0800
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> 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@intel.com>
Trivial comment inline you might want to consider.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  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@vger.kernel.org
> +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,
>  };
>