nvme: add set feature tracing support

A nvme connect command produces following trace.

Before:
/sys/kernel/debug/tracing# cat trace | grep feature
    kworker/5:1H-98      [005] ....  3221.294844: nvme_setup_cmd: nvme0: qid=0, cmdid=25, nsid=0, flags=0x0, meta=0x0, cmd=(nvme_admin_set_features cdw10=07 00 00 00 07 00 07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00)
    kworker/4:1H-124     [004] ....  3222.009186: nvme_setup_cmd: nvme0: qid=0, cmdid=17, nsid=0, flags=0x0, meta=0x0, cmd=(nvme_admin_set_features cdw10=0b 00 00 00 00 09 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00)

After:
/sys/kernel/debug/tracing# cat trace | grep feature
    kworker/0:1H-253     [000] ....   196.060509: nvme_setup_cmd: nvme0: qid=0, cmdid=29, nsid=0, flags=0x0, meta=0x0, cmd=(nvme_admin_set_features fid=0x7, sv=0x0, cdw11=0x70007)
    kworker/0:1H-253     [000] ....   196.763947: nvme_setup_cmd: nvme0: qid=0, cmdid=29, nsid=0, flags=0x0, meta=0x0, cmd=(nvme_admin_set_features fid=0xb, sv=0x0, cdw11=0x900)

Using ',' to separate different field like others in
nvmet_trace_admin_get_features.
Signed-off-by: Hou Pu <houpu.main@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/trace.c

@@ -72,6 +72,20 @@ static const char *nvme_trace_admin_identify(struct trace_seq *p, u8 *cdw10)
 	return ret;
 }
 
+static const char *nvme_trace_admin_set_features(struct trace_seq *p,
+						 u8 *cdw10)
+{
+	const char *ret = trace_seq_buffer_ptr(p);
+	u8 fid = cdw10[0];
+	u8 sv = cdw10[3] & 0x8;
+	u32 cdw11 = get_unaligned_le32(cdw10 + 4);
+
+	trace_seq_printf(p, "fid=0x%x, sv=0x%x, cdw11=0x%x", fid, sv, cdw11);
+	trace_seq_putc(p, 0);
+
+	return ret;
+}
+
 static const char *nvme_trace_admin_get_features(struct trace_seq *p,
 						 u8 *cdw10)
 {
@@ -80,7 +94,7 @@ static const char *nvme_trace_admin_get_features(struct trace_seq *p,
 	u8 sel = cdw10[1] & 0x7;
 	u32 cdw11 = get_unaligned_le32(cdw10 + 4);
 
-	trace_seq_printf(p, "fid=0x%x sel=0x%x cdw11=0x%x", fid, sel, cdw11);
+	trace_seq_printf(p, "fid=0x%x, sel=0x%x, cdw11=0x%x", fid, sel, cdw11);
 	trace_seq_putc(p, 0);
 
 	return ret;
@@ -201,6 +215,8 @@ const char *nvme_trace_parse_admin_cmd(struct trace_seq *p,
 		return nvme_trace_create_cq(p, cdw10);
 	case nvme_admin_identify:
 		return nvme_trace_admin_identify(p, cdw10);
+	case nvme_admin_set_features:
+		return nvme_trace_admin_set_features(p, cdw10);
 	case nvme_admin_get_features:
 		return nvme_trace_admin_get_features(p, cdw10);
 	case nvme_admin_get_lba_status: