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

Terry Bowman
2025-02-11T19:27:22Z

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'

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@amd.com>
Reviewed-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
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),
--
2.34.1