Re: [PATCH 3/4] cxl/pmem: Export dirty shutdown count via sysfs

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

On Wed, 19 Feb 2025 17:36:03 -0800
Davidlohr Bueso <dave@stgolabs.net> wrote:

> Similar to how the acpi_nfit driver exports Optane dirty shutdown count,
> introduce:
> 
>   /sys/bus/cxl/devices/nvdimm-bridge0/ndbusX/nmemY/cxl/dirty_shutdown
> 
> Under the conditions that 1) dirty shutdown can be set, 2) Device GPF
> DVSEC exists, and 3) the count itself can be retrieved.
> 
> Suggested-by: Dan Williams <dan.j.williams@intel.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
One trivial thing otherwise
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>


> diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c
> index 6b284962592f..cb039cfc62cb 100644
> --- a/drivers/cxl/pmem.c
> +++ b/drivers/cxl/pmem.c
> @@ -38,19 +38,48 @@ static ssize_t id_show(struct device *dev, struct device_attribute *attr, char *
>  	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
>  	struct cxl_dev_state *cxlds = cxl_nvd->cxlmd->cxlds;
>  
> -	return sysfs_emit(buf, "%lld\n", cxlds->serial);
> +	return sysfs_emit(buf, "%llu\n", cxlds->serial);

I guess you 'fixed' the wrong one?

>  }
>  static DEVICE_ATTR_RO(id);
>  
> +static ssize_t dirty_shutdown_show(struct device *dev,
> +				   struct device_attribute *attr, char *buf)
> +{
> +	struct nvdimm *nvdimm = to_nvdimm(dev);
> +	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
> +
> +	return sysfs_emit(buf, "%lld\n", cxl_nvd->dirty_shutdowns);

It's unsigned so %llu though I hope no one ever tests that by
doing that many dirty shutdowns.

> +}
> +static DEVICE_ATTR_RO(dirty_shutdown);