Re: [PATCH v7 10/17] cxl/pci: Add log message and add type check in existing RAS handlers

[Dave Jiang <dave.jiang@intel.com>]

On 2/11/25 12:24 PM, Terry Bowman wrote:
> The CXL RAS handlers do not currently log if the RAS registers are
> unmapped. This is needed in order to help debug CXL error handling. Update
> the CXL driver to log a warning message if the RAS register block is
> unmapped.
> 
> Also, add type check before processing EP or RCH DP.
> 
> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Reviewed-by: Gregory Price <gourry@gourry.net>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/cxl/core/pci.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 69bb030aa8e1..af809e7cbe3b 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -658,15 +658,19 @@ static void __cxl_handle_cor_ras(struct device *dev,
>  	void __iomem *addr;
>  	u32 status;
>  
> -	if (!ras_base)
> +	if (!ras_base) {
> +		dev_warn_once(dev, "CXL RAS register block is not mapped");
>  		return;
> +	}
>  
>  	addr = ras_base + CXL_RAS_CORRECTABLE_STATUS_OFFSET;
>  	status = readl(addr);
> -	if (status & CXL_RAS_CORRECTABLE_STATUS_MASK) {
> -		writel(status & CXL_RAS_CORRECTABLE_STATUS_MASK, addr);
> +	if (!(status & CXL_RAS_CORRECTABLE_STATUS_MASK))
> +		return;
> +	writel(status & CXL_RAS_CORRECTABLE_STATUS_MASK, addr);
> +
> +	if (is_cxl_memdev(dev))
>  		trace_cxl_aer_correctable_error(to_cxl_memdev(dev), status);
> -	}
>  }
>  
>  static void cxl_handle_endpoint_cor_ras(struct cxl_dev_state *cxlds)
> @@ -702,8 +706,10 @@ static bool __cxl_handle_ras(struct device *dev, void __iomem *ras_base)
>  	u32 status;
>  	u32 fe;
>  
> -	if (!ras_base)
> +	if (!ras_base) {
> +		dev_warn_once(dev, "CXL RAS register block is not mapped");
>  		return false;
> +	}
>  
>  	addr = ras_base + CXL_RAS_UNCORRECTABLE_STATUS_OFFSET;
>  	status = readl(addr);
> @@ -722,7 +728,9 @@ static bool __cxl_handle_ras(struct device *dev, void __iomem *ras_base)
>  	}
>  
>  	header_log_copy(ras_base, hl);
> -	trace_cxl_aer_uncorrectable_error(to_cxl_memdev(dev), status, fe, hl);
> +	if (is_cxl_memdev(dev))
> +		trace_cxl_aer_uncorrectable_error(to_cxl_memdev(dev), status, fe, hl);
> +
>  	writel(status & CXL_RAS_UNCORRECTABLE_STATUS_MASK, addr);
>  
>  	return true;