linux-kernel - Re: [PATCH 3/3 v5] cxl/memdev: Use cond_guard() in cxl_inject

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Date: Thu, 22 Feb 2024 11:27:35 -0700
From: Dave Jiang <dave.jiang@...el.com>
To: "Fabio M. De Francesco" <fabio.maria.de.francesco@...ux.intel.com>,
 Peter Zijlstra <peterz@...radead.org>,
 Dan Williams <dan.j.williams@...el.com>, linux-kernel@...r.kernel.org
Cc: linux-cxl@...r.kernel.org, Ingo Molnar <mingo@...nel.org>,
 Jonathan Cameron <Jonathan.Cameron@...wei.com>,
 Ira Weiny <ira.weiny@...el.com>
Subject: Re: [PATCH 3/3 v5] cxl/memdev: Use cond_guard() in
 cxl_inject_poison()



On 2/17/24 3:59 AM, Fabio M. De Francesco wrote:
> Use cond_guard() in cxl_inject_poison() to not open code two up_write()
> in an 'out' block. If the down_read_interruptible() fail, the statements
> passed as the second argument of cond_guard() return -EINTR.
> 
> Cc: Dave Jiang <dave.jiang@...el.com>
> Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Suggested-by: Dan Williams <dan.j.williams@...el.com>
> Suggested-by: Ira Weiny <ira.weiny@...el.com>
> Signed-off-by: Fabio M. De Francesco <fabio.maria.de.francesco@...ux.intel.com>

Reviewed-by: Dave Jiang <dave.jiang@...el.com>
> ---
>  drivers/cxl/core/memdev.c | 19 +++++--------------
>  1 file changed, 5 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> index dae8802ecdb0..bd97eea65bb0 100644
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c
> @@ -331,19 +331,13 @@ int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa)
>  	if (!IS_ENABLED(CONFIG_DEBUG_FS))
>  		return 0;
>  
> -	rc = down_read_interruptible(&cxl_region_rwsem);
> -	if (rc)
> -		return rc;
> +	cond_guard(rwsem_read_intr, return -EINTR, &cxl_region_rwsem);
>  
> -	rc = down_read_interruptible(&cxl_dpa_rwsem);
> -	if (rc) {
> -		up_read(&cxl_region_rwsem);
> -		return rc;
> -	}
> +	cond_guard(rwsem_read_intr, return -EINTR, &cxl_dpa_rwsem);
>  
>  	rc = cxl_validate_poison_dpa(cxlmd, dpa);
>  	if (rc)
> -		goto out;
> +		return rc;
>  
>  	inject.address = cpu_to_le64(dpa);
>  	mbox_cmd = (struct cxl_mbox_cmd) {
> @@ -353,7 +347,7 @@ int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa)
>  	};
>  	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
>  	if (rc)
> -		goto out;
> +		return rc;
>  
>  	cxlr = cxl_dpa_to_region(cxlmd, dpa);
>  	if (cxlr)
> @@ -366,11 +360,8 @@ int cxl_inject_poison(struct cxl_memdev *cxlmd, u64 dpa)
>  		.length = cpu_to_le32(1),
>  	};
>  	trace_cxl_poison(cxlmd, cxlr, &record, 0, 0, CXL_POISON_TRACE_INJECT);
> -out:
> -	up_read(&cxl_dpa_rwsem);
> -	up_read(&cxl_region_rwsem);
>  
> -	return rc;
> +	return 0;
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_inject_poison, CXL);
>