diff mbox series

[v2,4/4] acpi/ghes, cxl/pci: Trace FW-First CXL Protocol Errors

Message ID 20241001005234.61409-5-Smita.KoralahalliChannabasappa@amd.com
State New
Headers show
Series acpi/ghes, cper, cxl: Trace FW-First CXL Protocol Errors | expand

Commit Message

Smita Koralahalli Oct. 1, 2024, 12:52 a.m. UTC
When PCIe AER is in FW-First, OS should process CXL Protocol errors from
CPER records.

Reuse the existing work queue cxl_cper_work registered with GHES to notify
the CXL subsystem on a Protocol error.

The defined trace events cxl_aer_uncorrectable_error and
cxl_aer_correctable_error currently trace native CXL AER errors. Reuse
them to trace FW-First Protocol Errors.

Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
---
v2:
	Removed pr_warn for serial number.
	p_err -> rec/p_rec.
---
 drivers/acpi/apei/ghes.c | 14 ++++++++++++++
 drivers/cxl/core/pci.c   | 24 ++++++++++++++++++++++++
 drivers/cxl/cxlpci.h     |  3 +++
 drivers/cxl/pci.c        | 20 ++++++++++++++++++--
 include/cxl/event.h      |  1 +
 5 files changed, 60 insertions(+), 2 deletions(-)

Comments

Smita Koralahalli Oct. 3, 2024, 8:03 p.m. UTC | #1
On 10/2/2024 5:16 PM, Dan Williams wrote:
> Smita Koralahalli wrote:
>> When PCIe AER is in FW-First, OS should process CXL Protocol errors from
>> CPER records.
>>
>> Reuse the existing work queue cxl_cper_work registered with GHES to notify
>> the CXL subsystem on a Protocol error.
>>
>> The defined trace events cxl_aer_uncorrectable_error and
>> cxl_aer_correctable_error currently trace native CXL AER errors. Reuse
>> them to trace FW-First Protocol Errors.
>>
>> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
>> ---
>> v2:
>> 	Removed pr_warn for serial number.
>> 	p_err -> rec/p_rec.
>> ---
>>   drivers/acpi/apei/ghes.c | 14 ++++++++++++++
>>   drivers/cxl/core/pci.c   | 24 ++++++++++++++++++++++++
>>   drivers/cxl/cxlpci.h     |  3 +++
>>   drivers/cxl/pci.c        | 20 ++++++++++++++++++--
>>   include/cxl/event.h      |  1 +
>>   5 files changed, 60 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
>> index 9dcf0f78458f..5082885e1f2c 100644
>> --- a/drivers/acpi/apei/ghes.c
>> +++ b/drivers/acpi/apei/ghes.c
>> @@ -723,6 +723,20 @@ static void cxl_cper_handle_prot_err(struct acpi_hest_generic_data *gdata)
>>   
>>   	if (cxl_cper_handle_prot_err_info(gdata, &wd.p_rec))
>>   		return;
>> +
>> +	guard(spinlock_irqsave)(&cxl_cper_work_lock);
>> +
>> +	if (!cxl_cper_work)
>> +		return;
>> +
>> +	wd.event_type = CXL_CPER_EVENT_PROT_ERR;
>> +
>> +	if (!kfifo_put(&cxl_cper_fifo, wd)) {
>> +		pr_err_ratelimited("CXL CPER kfifo overflow\n");
>> +		return;
>> +	}
>> +
>> +	schedule_work(cxl_cper_work);
> 
> The cxl_cper_work item is only for cases where the cxl_pci driver might care
> about annotating an error report with driver specific details like the
> impacted kernel object name, 'struct cxl_memdev', or address translation
> for DPA data.
> 
> Protocol errors that are not endpoint errors should never be placed in
> the cxl_cper_fifo. That is exclusively for errors that cxl_pci needs to
> consume.
> 
> My expectation is that similar to aer_recover_queue for PCIe protocol
> errors CXL needs to grow a cxl_recover_queue that at a minimum triggers
> new trace events to dump these records to RAS daemon.
> 
> I am struggling to think what useful information cxl_pci could ever
> append to a protocol error event.
> 
> What is more likely is that later when Terry adds port error handling a
> CPER protocol error record could trigger a new cxl_do_recovery() to
> react to CXL topology errors that might impact downstream CXL devices.
> In that case the notification will come through something like a new
> 'struct cxl_error_handlers *' hanging off 'struct pci_driver' since
> accelerator drivers are going to have distinct error handling from
> generic memory expanders.

Hmm, I agree handling device and protocol errors separately. Unless 
Terry has something to add here, I can start working on a minimal 
version of cxl_recover_queue as of now.

Thanks
Smita
>
diff mbox series

Patch

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 9dcf0f78458f..5082885e1f2c 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -723,6 +723,20 @@  static void cxl_cper_handle_prot_err(struct acpi_hest_generic_data *gdata)
 
 	if (cxl_cper_handle_prot_err_info(gdata, &wd.p_rec))
 		return;
+
+	guard(spinlock_irqsave)(&cxl_cper_work_lock);
+
+	if (!cxl_cper_work)
+		return;
+
+	wd.event_type = CXL_CPER_EVENT_PROT_ERR;
+
+	if (!kfifo_put(&cxl_cper_fifo, wd)) {
+		pr_err_ratelimited("CXL CPER kfifo overflow\n");
+		return;
+	}
+
+	schedule_work(cxl_cper_work);
 }
 
 int cxl_cper_register_work(struct work_struct *work)
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 5b46bc46aaa9..39ef24c8991f 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -650,6 +650,30 @@  void read_cdat_data(struct cxl_port *port)
 }
 EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL);
 
+void cxl_trace_prot_err(struct cxl_dev_state *cxlds,
+			struct cxl_cper_prot_err *rec)
+{
+	u32 status, fe;
+
+	if (rec->severity == CXL_AER_CORRECTABLE) {
+		status = rec->cxl_ras.cor_status & ~rec->cxl_ras.cor_mask;
+
+		trace_cxl_aer_correctable_error(cxlds->cxlmd, status);
+	} else {
+		status = rec->cxl_ras.uncor_status & ~rec->cxl_ras.uncor_mask;
+
+		if (hweight32(status) > 1)
+			fe = BIT(FIELD_GET(CXL_RAS_CAP_CONTROL_FE_MASK,
+					   rec->cxl_ras.cap_control));
+		else
+			fe = status;
+
+		trace_cxl_aer_uncorrectable_error(cxlds->cxlmd, status, fe,
+						  rec->cxl_ras.header_log);
+	}
+}
+EXPORT_SYMBOL_NS_GPL(cxl_trace_prot_err, CXL);
+
 static void __cxl_handle_cor_ras(struct cxl_dev_state *cxlds,
 				 void __iomem *ras_base)
 {
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
index 4da07727ab9c..8acd8f2c39c9 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -129,4 +129,7 @@  void read_cdat_data(struct cxl_port *port);
 void cxl_cor_error_detected(struct pci_dev *pdev);
 pci_ers_result_t cxl_error_detected(struct pci_dev *pdev,
 				    pci_channel_state_t state);
+struct cxl_cper_prot_err;
+void cxl_trace_prot_err(struct cxl_dev_state *cxlds,
+			struct cxl_cper_prot_err *rec);
 #endif /* __CXL_PCI_H__ */
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 915102f5113f..0a29321921a0 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -1064,12 +1064,28 @@  static void cxl_handle_cper_event(enum cxl_event_type ev_type,
 			       &uuid_null, &rec->event);
 }
 
+static void cxl_handle_prot_err(struct cxl_cper_prot_err *rec)
+{
+	struct cxl_dev_state *cxlds;
+
+	cxlds = get_cxl_devstate(rec->segment, rec->bus,
+				 rec->device, rec->function);
+	if (!cxlds)
+		return;
+
+	cxl_trace_prot_err(cxlds, rec);
+}
+
 static void cxl_cper_work_fn(struct work_struct *work)
 {
 	struct cxl_cper_work_data wd;
 
-	while (cxl_cper_kfifo_get(&wd))
-		cxl_handle_cper_event(wd.event_type, &wd.rec);
+	while (cxl_cper_kfifo_get(&wd)) {
+		if (wd.event_type == CXL_CPER_EVENT_PROT_ERR)
+			cxl_handle_prot_err(&wd.p_rec);
+		else
+			cxl_handle_cper_event(wd.event_type, &wd.rec);
+	}
 }
 static DECLARE_WORK(cxl_cper_work, cxl_cper_work_fn);
 
diff --git a/include/cxl/event.h b/include/cxl/event.h
index 5b316150556a..d854d8c435db 100644
--- a/include/cxl/event.h
+++ b/include/cxl/event.h
@@ -115,6 +115,7 @@  struct cxl_event_record_raw {
 } __packed;
 
 enum cxl_event_type {
+	CXL_CPER_EVENT_PROT_ERR,
 	CXL_CPER_EVENT_GENERIC,
 	CXL_CPER_EVENT_GEN_MEDIA,
 	CXL_CPER_EVENT_DRAM,