Subject: Re: [PATCH v5 21/27] cxl/region: factor out interleave granularity setup

From: Zhi Wang <[email-masked]>
Date: Tue, 19 Nov 2024 22:23:01 +0200

On Mon, 18 Nov 2024 16:44:28 +0000
<[email-masked]> wrote:

LGTM. Reviewed-by: Zhi Wang <[email-masked]>

> From: Alejandro Lucero <[email-masked]>
> 
> In preparation for kernel driven region creation, factor out a common
> helper from the user-sysfs region setup for interleave granularity.
> 
> Signed-off-by: Alejandro Lucero <[email-masked]>
> Co-developed-by: Dan Williams <[email-masked]>
> ---
>  drivers/cxl/core/region.c | 39
> +++++++++++++++++++++++---------------- 1 file changed, 23
> insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 04f82adb763f..6652887ea396 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -540,21 +540,14 @@ static ssize_t
> interleave_granularity_show(struct device *dev, return rc;
>  }
>  
> -static ssize_t interleave_granularity_store(struct device *dev,
> -					    struct device_attribute
> *attr,
> -					    const char *buf, size_t
> len) +static int set_interleave_granularity(struct cxl_region *cxlr,
> int val) {
> -	struct cxl_root_decoder *cxlrd =
> to_cxl_root_decoder(dev->parent);
> +	struct cxl_root_decoder *cxlrd =
> to_cxl_root_decoder(cxlr->dev.parent); struct cxl_decoder *cxld =
> &cxlrd->cxlsd.cxld;
> -	struct cxl_region *cxlr = to_cxl_region(dev);
>  	struct cxl_region_params *p = &cxlr->params;
> -	int rc, val;
> +	int rc;
>  	u16 ig;
>  
> -	rc = kstrtoint(buf, 0, &val);
> -	if (rc)
> -		return rc;
> -
>  	rc = granularity_to_eig(val, &ig);
>  	if (rc)
>  		return rc;
> @@ -570,16 +563,30 @@ static ssize_t
> interleave_granularity_store(struct device *dev, if
> (cxld->interleave_ways > 1 && val != cxld->interleave_granularity)
> return -EINVAL; 
> +	lockdep_assert_held_write(&cxl_region_rwsem);
> +	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE)
> +		return -EBUSY;
> +
> +	p->interleave_granularity = val;
> +	return 0;
> +}
> +
> +static ssize_t interleave_granularity_store(struct device *dev,
> +					    struct device_attribute
> *attr,
> +					    const char *buf, size_t
> len) +{
> +	struct cxl_region *cxlr = to_cxl_region(dev);
> +	int rc, val;
> +
> +	rc = kstrtoint(buf, 0, &val);
> +	if (rc)
> +		return rc;
> +
>  	rc = down_write_killable(&cxl_region_rwsem);
>  	if (rc)
>  		return rc;
> -	if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) {
> -		rc = -EBUSY;
> -		goto out;
> -	}
>  
> -	p->interleave_granularity = val;
> -out:
> +	rc = set_interleave_granularity(cxlr, val);
>  	up_write(&cxl_region_rwsem);
>  	if (rc)
>  		return rc;