Re: [PATCH v3 6/8] cxl/region: Move ready-to-probe state check to a helper

["Fabio M. De Francesco" <fabio.m.de.francesco@linux.intel.com>]

On Saturday, July 12, 2025 1:49:30 AM Central European Summer Time Dan Williams wrote:
> Rather than unlocking the region rwsem in the middle of cxl_region_probe()
> create a helper for determining when the region is ready-to-probe.
> 
> Cc: Davidlohr Bueso <dave@stgolabs.net>
> Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Alison Schofield <alison.schofield@intel.com>
> Cc: Vishal Verma <vishal.l.verma@intel.com>
> Cc: Ira Weiny <ira.weiny@intel.com>
> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Fabio M. De Francesco <fabio.m.de.francesco@linux.intel.com>

> ---
>  drivers/cxl/core/region.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 3a77aec2c447..2a97fa9a394f 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -3572,9 +3572,8 @@ static void shutdown_notifiers(void *_cxlr)
>  	unregister_mt_adistance_algorithm(&cxlr->adist_notifier);
>  }
>  
> -static int cxl_region_probe(struct device *dev)
> +static int cxl_region_can_probe(struct cxl_region *cxlr)
>  {
> -	struct cxl_region *cxlr = to_cxl_region(dev);
>  	struct cxl_region_params *p = &cxlr->params;
>  	int rc;
>  
> @@ -3597,15 +3596,28 @@ static int cxl_region_probe(struct device *dev)
>  		goto out;
>  	}
>  
> -	/*
> -	 * From this point on any path that changes the region's state away from
> -	 * CXL_CONFIG_COMMIT is also responsible for releasing the driver.
> -	 */
>  out:
>  	up_read(&cxl_region_rwsem);
>  
>  	if (rc)
>  		return rc;
> +	return 0;
> +}
> +
> +static int cxl_region_probe(struct device *dev)
> +{
> +	struct cxl_region *cxlr = to_cxl_region(dev);
> +	struct cxl_region_params *p = &cxlr->params;
> +	int rc;
> +
> +	rc = cxl_region_can_probe(cxlr);
> +	if (rc)
> +		return rc;
> +
> +	/*
> +	 * From this point on any path that changes the region's state away from
> +	 * CXL_CONFIG_COMMIT is also responsible for releasing the driver.
> +	 */
>  
>  	cxlr->memory_notifier.notifier_call = cxl_region_perf_attrs_callback;
>  	cxlr->memory_notifier.priority = CXL_CALLBACK_PRI;
> -- 
> 2.50.0
> 
> 
>