[PATCH v1 2/2] scsi: ufs: Add trace event for UIC commands

From: Stanley Chu
Date: Fri Jun 12 2020 - 11:10:44 EST


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
- UIC command execution result

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>
---
drivers/scsi/ufs/ufshcd.c | 29 +++++++++++++++++++++++++++++
include/trace/events/ufs.h | 33 +++++++++++++++++++++++++++++++++
2 files changed, 62 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c197a3315d21..181617966658 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -339,6 +339,27 @@ 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, "uic_send"))
+ cmd = ucmd->command;
+ else
+ cmd = ufshcd_readl(hba, REG_UIC_COMMAND);
+
+ trace_ufshcd_uic_command(dev_name(hba->dev), str, cmd,
+ ucmd->result,
+ 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)
{
@@ -2054,6 +2075,8 @@ ufshcd_dispatch_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
/* Write UIC Cmd */
ufshcd_writel(hba, uic_cmd->command & COMMAND_OPCODE_MASK,
REG_UIC_COMMAND);
+
+ ufshcd_add_uic_command_trace(hba, uic_cmd, "uic_send");
}

/**
@@ -2080,6 +2103,9 @@ ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
hba->active_uic_cmd = NULL;
spin_unlock_irqrestore(hba->host->host_lock, flags);

+ uic_cmd->result = ret;
+ ufshcd_add_uic_command_trace(hba, uic_cmd, "uic_complete");
+
return ret;
}

@@ -3760,6 +3786,9 @@ static int ufshcd_uic_pwr_ctrl(struct ufs_hba *hba, struct uic_command *cmd)
ret = (status != PWR_OK) ? status : -1;
}
out:
+ cmd->result = ret;
+ ufshcd_add_uic_command_trace(hba, cmd, "uic_complete");
+
if (ret) {
ufshcd_print_host_state(hba);
ufshcd_print_pwr_info(hba);
diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
index 5f300739240d..cf8d568d5a13 100644
--- a/include/trace/events/ufs.h
+++ b/include/trace/events/ufs.h
@@ -249,6 +249,39 @@ TRACE_EVENT(ufshcd_command,
)
);

+TRACE_EVENT(ufshcd_uic_command,
+ TP_PROTO(const char *dev_name, const char *str, u32 cmd, int result,
+ u32 arg1, u32 arg2, u32 arg3),
+
+ TP_ARGS(dev_name, str, cmd, result, arg1, arg2, arg3),
+
+ TP_STRUCT__entry(
+ __string(dev_name, dev_name)
+ __string(str, str)
+ __field(u32, cmd)
+ __field(int, result)
+ __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->result = result;
+ __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, result: %d",
+ __get_str(str), __get_str(dev_name), __entry->cmd,
+ __entry->arg1, __entry->arg2, __entry->arg3, __entry->result
+ )
+);
+
TRACE_EVENT(ufshcd_upiu,
TP_PROTO(const char *dev_name, const char *str, void *hdr, void *tsf),

--
2.18.0