Re: [PATCH v7 13/17] cxl/pci: Add trace logging for CXL PCIe Port RAS errors

[Dave Jiang]

On 2/11/25 5:17 PM, Dave Jiang wrote:
> 
> 
> On 2/11/25 12:24 PM, Terry Bowman wrote:
>> The CXL drivers use kernel trace functions for logging Endpoint and
>> Restricted CXL host (RCH) Downstream Port RAS errors. Similar functionality
>> is required for CXL Root Ports, CXL Downstream Switch Ports, and CXL
>> Upstream Switch Ports.
>>
>> Introduce trace logging functions for both RAS correctable and
>> uncorrectable errors specific to CXL PCIe Ports. Additionally, update
>> the CXL Port Protocol Error handlers to invoke these new trace functions.
>>
>> Examples of the output from these changes is below.
>>
>> Correctable error:
>> cxl_port_aer_correctable_error: device=port1 parent=root0 status='Received Error From Physical Layer'
> 
> Is there any way to identify if the error comes from the USP or DSP? Specifically the PCI devname for the specific port?

Hah I spoke too soon. You addressed it in the next patch. :)

DJ

>>
>> Uncorrectable error:
>> cxl_port_aer_uncorrectable_error: device=port1 parent=root0 status: 'Memory Byte Enable Parity Error' first_error: 'Memory Byte Enable Parity Erro'
>>
>> Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
>> Reviewed-by: Alejandro Lucero <alucerop@xxxxxxx>
>> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> 
> Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> 
>> ---
>>  drivers/cxl/core/pci.c   |  4 ++++
>>  drivers/cxl/core/trace.h | 47 ++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 51 insertions(+)
>>
>> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
>> index 3f13d9dfb610..9a3090dae46a 100644
>> --- a/drivers/cxl/core/pci.c
>> +++ b/drivers/cxl/core/pci.c
>> @@ -671,6 +671,8 @@ static void __cxl_handle_cor_ras(struct device *dev,
>>  
>>  	if (is_cxl_memdev(dev))
>>  		trace_cxl_aer_correctable_error(to_cxl_memdev(dev), status);
>> +	else if (is_cxl_port(dev))
>> +		trace_cxl_port_aer_correctable_error(dev, status);
>>  }
>>  
>>  static void cxl_handle_endpoint_cor_ras(struct cxl_dev_state *cxlds)
>> @@ -730,6 +732,8 @@ static pci_ers_result_t __cxl_handle_ras(struct device *dev, void __iomem *ras_b
>>  	header_log_copy(ras_base, hl);
>>  	if (is_cxl_memdev(dev))
>>  		trace_cxl_aer_uncorrectable_error(to_cxl_memdev(dev), status, fe, hl);
>> +	else if (is_cxl_port(dev))
>> +		trace_cxl_port_aer_uncorrectable_error(dev, status, fe, hl);
>>  
>>  	writel(status & CXL_RAS_UNCORRECTABLE_STATUS_MASK, addr);
>>  
>> diff --git a/drivers/cxl/core/trace.h b/drivers/cxl/core/trace.h
>> index cea706b683b5..b536233ac210 100644
>> --- a/drivers/cxl/core/trace.h
>> +++ b/drivers/cxl/core/trace.h
>> @@ -48,6 +48,34 @@
>>  	{ CXL_RAS_UC_IDE_RX_ERR, "IDE Rx Error" }			  \
>>  )
>>  
>> +TRACE_EVENT(cxl_port_aer_uncorrectable_error,
>> +	TP_PROTO(struct device *dev, u32 status, u32 fe, u32 *hl),
>> +	TP_ARGS(dev, status, fe, hl),
>> +	TP_STRUCT__entry(
>> +		__string(devname, dev_name(dev))
>> +		__string(parent, dev_name(dev->parent))
>> +		__field(u32, status)
>> +		__field(u32, first_error)
>> +		__array(u32, header_log, CXL_HEADERLOG_SIZE_U32)
>> +	),
>> +	TP_fast_assign(
>> +		__assign_str(devname);
>> +		__assign_str(parent);
>> +		__entry->status = status;
>> +		__entry->first_error = fe;
>> +		/*
>> +		 * Embed the 512B headerlog data for user app retrieval and
>> +		 * parsing, but no need to print this in the trace buffer.
>> +		 */
>> +		memcpy(__entry->header_log, hl, CXL_HEADERLOG_SIZE);
>> +	),
>> +	TP_printk("device=%s parent=%s status: '%s' first_error: '%s'",
>> +		__get_str(devname), __get_str(parent),
>> +		show_uc_errs(__entry->status),
>> +		show_uc_errs(__entry->first_error)
>> +	)
>> +);
>> +
>>  TRACE_EVENT(cxl_aer_uncorrectable_error,
>>  	TP_PROTO(const struct cxl_memdev *cxlmd, u32 status, u32 fe, u32 *hl),
>>  	TP_ARGS(cxlmd, status, fe, hl),
>> @@ -96,6 +124,25 @@ TRACE_EVENT(cxl_aer_uncorrectable_error,
>>  	{ CXL_RAS_CE_PHYS_LAYER_ERR, "Received Error From Physical Layer" }	\
>>  )
>>  
>> +TRACE_EVENT(cxl_port_aer_correctable_error,
>> +	TP_PROTO(struct device *dev, u32 status),
>> +	TP_ARGS(dev, status),
>> +	TP_STRUCT__entry(
>> +		__string(devname, dev_name(dev))
>> +		__string(parent, dev_name(dev->parent))
>> +		__field(u32, status)
>> +	),
>> +	TP_fast_assign(
>> +		__assign_str(devname);
>> +		__assign_str(parent);
>> +		__entry->status = status;
>> +	),
>> +	TP_printk("device=%s parent=%s status='%s'",
>> +		__get_str(devname), __get_str(parent),
>> +		show_ce_errs(__entry->status)
>> +	)
>> +);
>> +
>>  TRACE_EVENT(cxl_aer_correctable_error,
>>  	TP_PROTO(const struct cxl_memdev *cxlmd, u32 status),
>>  	TP_ARGS(cxlmd, status),
> 
>