From f7733625ec2f7bd628e4fd5014f72a2983830a74 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 9 Feb 2021 08:24:34 +0200 Subject: [PATCH] scsi: ufs: Add exception event tracepoint Currently, exception event status can be read from wExceptionEventStatus attribute (sysfs file attributes/exception_event_status under the UFS host controller device directory). Polling that attribute to track UFS exception events is impractical, so add a tracepoint to track exception events for testing and debugging purposes. Note, by the time the exception event status is read, the exception event may have cleared, so the value can be zero - see example below. Note also, only enabled exception events can be reported. A subsequent patch adds the ability for users to enable selected exception events via debugfs. Example with driver instrumented to enable all exception events: # echo 1 > /sys/kernel/debug/tracing/events/ufs/ufshcd_exception_event/enable ... do some I/O ... # cat /sys/kernel/debug/tracing/trace # tracer: nop # # entries-in-buffer/entries-written: 3/3 #P:5 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | kworker/2:2-173 [002] .... 731.486419: ufshcd_exception_event: 0000:00:12.5: status 0x0 kworker/2:2-173 [002] .... 732.608918: ufshcd_exception_event: 0000:00:12.5: status 0x4 kworker/2:2-173 [002] .... 732.609312: ufshcd_exception_event: 0000:00:12.5: status 0x4 Link: https://lore.kernel.org/r/20210209062437.6954-2-adrian.hunter@intel.com Reviewed-by: Avri Altman Reviewed-by: Bean Huo Signed-off-by: Adrian Hunter Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 2 ++ include/trace/events/ufs.h | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 7716175..98b4cc08 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5618,6 +5618,8 @@ static void ufshcd_exception_event_handler(struct work_struct *work) goto out; } + trace_ufshcd_exception_event(dev_name(hba->dev), status); + status &= hba->ee_ctrl_mask; if (status & MASK_EE_URGENT_BKOPS) diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h index e151477..1cb6f1a 100644 --- a/include/trace/events/ufs.h +++ b/include/trace/events/ufs.h @@ -349,6 +349,27 @@ TRACE_EVENT(ufshcd_upiu, ) ); +TRACE_EVENT(ufshcd_exception_event, + + TP_PROTO(const char *dev_name, u16 status), + + TP_ARGS(dev_name, status), + + TP_STRUCT__entry( + __string(dev_name, dev_name) + __field(u16, status) + ), + + TP_fast_assign( + __assign_str(dev_name, dev_name); + __entry->status = status; + ), + + TP_printk("%s: status 0x%x", + __get_str(dev_name), __entry->status + ) +); + #endif /* if !defined(_TRACE_UFS_H) || defined(TRACE_HEADER_MULTI_READ) */ /* This part must be outside protection */ -- 2.7.4