From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Date: Tue, 19 May 2020 01:06:30 -0700
Subject: [PATCH] nvmet: add async event tracing support
Git-commit: 696ece751366e7a02a81fa0228125fe25a47969d
Patch-mainline: v5.8-rc1
References: jsc#SLE-15608
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This adds a new tracepoint for the target to trace async event. This is
helpful in debugging and comparing host and target side async events
especially when host is connected to different targets on different
machines and now that we rely on userspace components to generate AEN. 

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/nvme/target/core.c  |  1 +
 drivers/nvme/target/trace.h | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index b685f99d56a1..7ce3d3b0f5d6 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -151,6 +151,7 @@ static void nvmet_async_events_process(struct nvmet_ctrl *ctrl, u16 status)
 		kfree(aen);
 
 		mutex_unlock(&ctrl->lock);
+		trace_nvmet_async_event(ctrl, req->cqe->result.u32);
 		nvmet_req_complete(req, status);
 	}
 }
diff --git a/drivers/nvme/target/trace.h b/drivers/nvme/target/trace.h
index e645caa882dd..0458046d6501 100644
--- a/drivers/nvme/target/trace.h
+++ b/drivers/nvme/target/trace.h
@@ -130,6 +130,34 @@ TRACE_EVENT(nvmet_req_complete,
 
 );
 
+#define aer_name(aer) { aer, #aer }
+
+TRACE_EVENT(nvmet_async_event,
+	TP_PROTO(struct nvmet_ctrl *ctrl, __le32 result),
+	TP_ARGS(ctrl, result),
+	TP_STRUCT__entry(
+		__field(int, ctrl_id)
+		__field(u32, result)
+	),
+	TP_fast_assign(
+		__entry->ctrl_id = ctrl->cntlid;
+		__entry->result = (le32_to_cpu(result) & 0xff00) >> 8;
+	),
+	TP_printk("nvmet%d: NVME_AEN=%#08x [%s]",
+		__entry->ctrl_id, __entry->result,
+		__print_symbolic(__entry->result,
+		aer_name(NVME_AER_NOTICE_NS_CHANGED),
+		aer_name(NVME_AER_NOTICE_ANA),
+		aer_name(NVME_AER_NOTICE_FW_ACT_STARTING),
+		aer_name(NVME_AER_NOTICE_DISC_CHANGED),
+		aer_name(NVME_AER_ERROR),
+		aer_name(NVME_AER_SMART),
+		aer_name(NVME_AER_CSS),
+		aer_name(NVME_AER_VS))
+	)
+);
+#undef aer_name
+
 #endif /* _TRACE_NVMET_H */
 
 #undef TRACE_INCLUDE_PATH
-- 
2.16.4