[v1,2/2] scsi: ufs: Add trace event for UIC commands
diff mbox series

Message ID 20200612151000.27639-3-stanley.chu@mediatek.com
State New
Headers show
Series
  • scsi: ufs: Add trace event for UIC commands
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Commit Message

Stanley Chu June 12, 2020, 3:10 p.m. UTC
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@mediatek.com>
---
 drivers/scsi/ufs/ufshcd.c  | 29 +++++++++++++++++++++++++++++
 include/trace/events/ufs.h | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

Comments

Avri Altman June 13, 2020, 10:48 a.m. UTC | #1
> +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);
Why on complete you can't just use ucmd->command as well?

> +
> +       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));
Why can't you just use the ucmd members?
Why need to read those?

> +}


> +
>  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;
>  }
Can't you just call the "send" and "complete" from ufshcd_send_uic_cmd?


> 
> @@ -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
> +       )
Personally, as those trace events aren't very human readable anyway, I would just dump the uic command,
And let the parsers do their job.
And if this is the case, result is redundant as it is part of arg2

Thanks,
Avri

> +);
> +
>  TRACE_EVENT(ufshcd_upiu,
>         TP_PROTO(const char *dev_name, const char *str, void *hdr, void *tsf),
> 
> --
> 2.18.0
Stanley Chu June 13, 2020, 2:18 p.m. UTC | #2
Hi Avri,

On Sat, 2020-06-13 at 10:48 +0000, Avri Altman wrote:
> > +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);
> Why on complete you can't just use ucmd->command as well?

Reading registers is really helpful for debugging to check if host UIC
command register really received the command before.

But the original requesting UIC command shall be logged in trace so
ucmd->command is logged during "send", and the command in register is
read and logged during "completed". Then we could simply check them to
know if something wrong while sending the command.

This concept is similar as current UTP command trace events that
doorbell register is read and dumped in the trace.

> 
> > +
> > +       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));
> Why can't you just use the ucmd members?
> Why need to read those?

As above same reason, reading registers can know which arguments are
exactly sent to the device.

This is very helpful for fast issue breakdown if UIC command is not
responded under expectation.

Here, we also really want to keep the original requesting arguments from
"ucmd", just like UIC command. However, arguments in register will be
changed after UIC command is done so we can not do the same way as UIC
command. So a compromise is here that we logged the arguments which host
register exactly received in trace.

> 
> > +}
> 
> 
> > +
> >  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;
> >  }
> Can't you just call the "send" and "complete" from ufshcd_send_uic_cmd?

For "send", we would like to log the time as precise as possible so
"send" event is logged while UIC command is sent.

Thanks so much! Your question reminds me that "send" trace shall be
moved before UIC command is sent otherwise register value may be changed
before logging "send" trace. I will fix this in next version.

For "completed", to make logging time as closed to UIC command
completion as possible, maybe I need to change the logging timing to
ufshcd_uic_cmd_compl(), just like UTP command completion trace which is
logged in __ufshcd_transfer_reg_compl().

If you have no objection, I will try to fix this in next version.

> 
> 
> > 
> > @@ -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
> > +       )
> Personally, as those trace events aren't very human readable anyway, I would just dump the uic command,
> And let the parsers do their job.
> And if this is the case, result is redundant as it is part of arg2

My original thought is to log some exceptions, like "-ETIMEDOUT" in
"result". But if I changed "completion" trace handling to interrupt
handler, there will be no chance to log those exceptions. This is OK
because UTP trace is exactly behave this way: No completion event in
trace if request is not back. And if this way is implemented, "result"
is definitely redundant and shall be removed.

Thanks,
Stanley Chu
Avri Altman June 14, 2020, 9:27 a.m. UTC | #3
Acked-by: Avri Altman <avri.altman@wdc.com>

> 
> 
> Hi Avri,
> 
> On Sat, 2020-06-13 at 10:48 +0000, Avri Altman wrote:
> > > +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);
> > Why on complete you can't just use ucmd->command as well?
> 
> Reading registers is really helpful for debugging to check if host UIC
> command register really received the command before.
> 
> But the original requesting UIC command shall be logged in trace so
> ucmd->command is logged during "send", and the command in register is
> read and logged during "completed". Then we could simply check them to
> know if something wrong while sending the command.
> 
> This concept is similar as current UTP command trace events that
> doorbell register is read and dumped in the trace.
> 
> >
> > > +
> > > +       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));
> > Why can't you just use the ucmd members?
> > Why need to read those?
> 
> As above same reason, reading registers can know which arguments are
> exactly sent to the device.
> 
> This is very helpful for fast issue breakdown if UIC command is not
> responded under expectation.
> 
> Here, we also really want to keep the original requesting arguments from
> "ucmd", just like UIC command. However, arguments in register will be
> changed after UIC command is done so we can not do the same way as UIC
> command. So a compromise is here that we logged the arguments which host
> register exactly received in trace.
> 
> >
> > > +}
> >
> >
> > > +
> > >  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;
> > >  }
> > Can't you just call the "send" and "complete" from ufshcd_send_uic_cmd?
> 
> For "send", we would like to log the time as precise as possible so
> "send" event is logged while UIC command is sent.
> 
> Thanks so much! Your question reminds me that "send" trace shall be
> moved before UIC command is sent otherwise register value may be changed
> before logging "send" trace. I will fix this in next version.
> 
> For "completed", to make logging time as closed to UIC command
> completion as possible, maybe I need to change the logging timing to
> ufshcd_uic_cmd_compl(), just like UTP command completion trace which is
> logged in __ufshcd_transfer_reg_compl().
> 
> If you have no objection, I will try to fix this in next version.
> 
> >
> >
> > >
> > > @@ -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
> > > +       )
> > Personally, as those trace events aren't very human readable anyway, I
> would just dump the uic command,
> > And let the parsers do their job.
> > And if this is the case, result is redundant as it is part of arg2
> 
> My original thought is to log some exceptions, like "-ETIMEDOUT" in
> "result". But if I changed "completion" trace handling to interrupt
> handler, there will be no chance to log those exceptions. This is OK
> because UTP trace is exactly behave this way: No completion event in
> trace if request is not back. And if this way is implemented, "result"
> is definitely redundant and shall be removed.
> 
> Thanks,
> Stanley Chu

Patch
diff mbox series

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),