[PATCH v3 2/2] scsi: ufs: Add trace event for UIC commands

[Stanley Chu <stanley.chu@xxxxxxxxxxxx>]

Use the ftrace infrastructure to conditionally trace UFS UIC command
events.

New trace event "ufshcd_uic_command" is created, which samples the
following UFS UIC command data:
- Device name
- Optional identification string
- UIC command opcode
- UIC command argument1
- UIC command argument2
- UIC command argement3

Usage:
	echo 1 > /sys/kernel/debug/tracing/events/ufs/enable
	cat /sys/kernel/debug/tracing/trace_pipe

Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Acked-by: Avri Altman <avri.altman@xxxxxxx>
---
 drivers/scsi/ufs/ufshcd.c  | 26 ++++++++++++++++++++++++++
 include/trace/events/ufs.h | 31 +++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ad4fc829cbb2..1e1316ba7082 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -340,6 +340,26 @@ static void ufshcd_add_tm_upiu_trace(struct ufs_hba *hba, unsigned int tag,
 			&descp->input_param1);
 }
 
+static void ufshcd_add_uic_command_trace(struct ufs_hba *hba,
+					 struct uic_command *ucmd,
+					 const char *str)
+{
+	u32 cmd;
+
+	if (!trace_ufshcd_uic_command_enabled())
+		return;
+
+	if (!strcmp(str, "send"))
+		cmd = ucmd->command;
+	else
+		cmd = ufshcd_readl(hba, REG_UIC_COMMAND);
+
+	trace_ufshcd_uic_command(dev_name(hba->dev), str, cmd,
+				 ufshcd_readl(hba, REG_UIC_COMMAND_ARG_1),
+				 ufshcd_readl(hba, REG_UIC_COMMAND_ARG_2),
+				 ufshcd_readl(hba, REG_UIC_COMMAND_ARG_3));
+}
+
 static void ufshcd_add_command_trace(struct ufs_hba *hba,
 		unsigned int tag, const char *str)
 {
@@ -2052,6 +2072,8 @@ ufshcd_dispatch_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
 	ufshcd_writel(hba, uic_cmd->argument2, REG_UIC_COMMAND_ARG_2);
 	ufshcd_writel(hba, uic_cmd->argument3, REG_UIC_COMMAND_ARG_3);
 
+	ufshcd_add_uic_command_trace(hba, uic_cmd, "send");
+
 	/* Write UIC Cmd */
 	ufshcd_writel(hba, uic_cmd->command & COMMAND_OPCODE_MASK,
 		      REG_UIC_COMMAND);
@@ -4833,6 +4855,10 @@ static irqreturn_t ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
 		complete(hba->uic_async_done);
 		retval = IRQ_HANDLED;
 	}
+
+	if (retval == IRQ_HANDLED)
+		ufshcd_add_uic_command_trace(hba, hba->active_uic_cmd,
+					     "complete");
 	return retval;
 }
 
diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
index 5f300739240d..84841b3a7ffd 100644
--- a/include/trace/events/ufs.h
+++ b/include/trace/events/ufs.h
@@ -249,6 +249,37 @@ TRACE_EVENT(ufshcd_command,
 	)
 );
 
+TRACE_EVENT(ufshcd_uic_command,
+	TP_PROTO(const char *dev_name, const char *str, u32 cmd,
+		 u32 arg1, u32 arg2, u32 arg3),
+
+	TP_ARGS(dev_name, str, cmd, arg1, arg2, arg3),
+
+	TP_STRUCT__entry(
+		__string(dev_name, dev_name)
+		__string(str, str)
+		__field(u32, cmd)
+		__field(u32, arg1)
+		__field(u32, arg2)
+		__field(u32, arg3)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev_name, dev_name);
+		__assign_str(str, str);
+		__entry->cmd = cmd;
+		__entry->arg1 = arg1;
+		__entry->arg2 = arg2;
+		__entry->arg3 = arg3;
+	),
+
+	TP_printk(
+		"%s: %s: cmd: 0x%x, arg1: 0x%x, arg2: 0x%x, arg3: 0x%x",
+		__get_str(str), __get_str(dev_name), __entry->cmd,
+		__entry->arg1, __entry->arg2, __entry->arg3
+	)
+);
+
 TRACE_EVENT(ufshcd_upiu,
 	TP_PROTO(const char *dev_name, const char *str, void *hdr, void *tsf),
 
-- 
2.18.0