linux-kernel - Re: [PATCH v6 05/27] cxl/hdm: Use guard() in cxl_dpa_set

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Message-ID: <20241107110810.00000fc1@Huawei.com>
Date: Thu, 7 Nov 2024 11:08:10 +0000
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
To: Ira Weiny <ira.weiny@...el.com>
CC: Dave Jiang <dave.jiang@...el.com>, Fan Ni <fan.ni@...sung.com>, "Navneet
 Singh" <navneet.singh@...el.com>, Jonathan Corbet <corbet@....net>, "Andrew
 Morton" <akpm@...ux-foundation.org>, Dan Williams <dan.j.williams@...el.com>,
	Davidlohr Bueso <dave@...olabs.net>, "Alison Schofield"
	<alison.schofield@...el.com>, Vishal Verma <vishal.l.verma@...el.com>,
	<linux-cxl@...r.kernel.org>, <linux-doc@...r.kernel.org>,
	<nvdimm@...ts.linux.dev>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v6 05/27] cxl/hdm: Use guard() in cxl_dpa_set_mode()

On Tue, 05 Nov 2024 12:38:27 -0600
Ira Weiny <ira.weiny@...el.com> wrote:

> Additional DCD functionality is being added to this call which will be
> simplified by the use of guard() with the cxl_dpa_rwsem.
> 
> Convert the function to use guard() prior to adding DCD functionality.
> 
> Suggested-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> Signed-off-by: Ira Weiny <ira.weiny@...el.com>

You missed some RBs from v5 and I don't think this changed.

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

Davidlohr also gave one.

> ---
>  drivers/cxl/core/hdm.c | 21 ++++++---------------
>  1 file changed, 6 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> index 3df10517a3278f228c7535fcbdb607d7b75bc879..463ba2669cea55194e2be2c26d02af75dde8d145 100644
> --- a/drivers/cxl/core/hdm.c
> +++ b/drivers/cxl/core/hdm.c
> @@ -424,7 +424,6 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
>  	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
>  	struct cxl_dev_state *cxlds = cxlmd->cxlds;
>  	struct device *dev = &cxled->cxld.dev;
> -	int rc;
>  
>  	switch (mode) {
>  	case CXL_DECODER_RAM:
> @@ -435,11 +434,9 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
>  		return -EINVAL;
>  	}
>  
> -	down_write(&cxl_dpa_rwsem);
> -	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
> -		rc = -EBUSY;
> -		goto out;
> -	}
> +	guard(rwsem_write)(&cxl_dpa_rwsem);
> +	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE)
> +		return -EBUSY;
>  
>  	/*
>  	 * Only allow modes that are supported by the current partition
> @@ -447,21 +444,15 @@ int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
>  	 */
>  	if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) {
>  		dev_dbg(dev, "no available pmem capacity\n");
> -		rc = -ENXIO;
> -		goto out;
> +		return -ENXIO;
>  	}
>  	if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) {
>  		dev_dbg(dev, "no available ram capacity\n");
> -		rc = -ENXIO;
> -		goto out;
> +		return -ENXIO;
>  	}
>  
>  	cxled->mode = mode;
> -	rc = 0;
> -out:
> -	up_write(&cxl_dpa_rwsem);
> -
> -	return rc;
> +	return 0;
>  }
>  
>  int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size)
>