stm class: Propagate source type to protocols

Pass stm source type via stm_write() to allow different handling on
protocol level.

The measure above should allow protocol level encoder to differentiate
and accordingly pack the messages. As an example SyS-T might get use of
ftrace message ID's and instead of applying regular header, pack them
as SyS-T catalog or SyS-T Structured Binary Data message to allow proper
decoding on the other side.

Signed-off-by: Mikhail Lappo <miklelappo@gmail.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240429130119.1518073-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: miklelappo

drivers/hwtracing/stm/core.c

@@ -600,15 +600,15 @@ EXPORT_SYMBOL_GPL(stm_data_write);
 
 static ssize_t notrace
 stm_write(struct stm_device *stm, struct stm_output *output,
-	  unsigned int chan, const char *buf, size_t count)
+	  unsigned int chan, const char *buf, size_t count, struct stm_source_data *source)
 {
 	int err;
 
 	/* stm->pdrv is serialized against policy_mutex */
 	if (!stm->pdrv)
 		return -ENODEV;
 
-	err = stm->pdrv->write(stm->data, output, chan, buf, count);
+	err = stm->pdrv->write(stm->data, output, chan, buf, count, source);
 	if (err < 0)
 		return err;
 
@@ -657,7 +657,7 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf,
 
 	pm_runtime_get_sync(&stm->dev);
 
-	count = stm_write(stm, &stmf->output, 0, kbuf, count);
+	count = stm_write(stm, &stmf->output, 0, kbuf, count, NULL);
 
 	pm_runtime_mark_last_busy(&stm->dev);
 	pm_runtime_put_autosuspend(&stm->dev);
@@ -1299,7 +1299,7 @@ int notrace stm_source_write(struct stm_source_data *data,
 
 	stm = srcu_dereference(src->link, &stm_source_srcu);
 	if (stm)
-		count = stm_write(stm, &src->output, chan, buf, count);
+		count = stm_write(stm, &src->output, chan, buf, count, data);
 	else
 		count = -ENODEV;
 

drivers/hwtracing/stm/p_basic.c

@@ -10,7 +10,8 @@
 #include "stm.h"
 
 static ssize_t basic_write(struct stm_data *data, struct stm_output *output,
-			   unsigned int chan, const char *buf, size_t count)
+			   unsigned int chan, const char *buf, size_t count,
+			   struct stm_source_data *source)
 {
 	unsigned int c = output->channel + chan;
 	unsigned int m = output->master;

drivers/hwtracing/stm/p_sys-t.c

@@ -285,7 +285,8 @@ sys_t_clock_sync(struct stm_data *data, unsigned int m, unsigned int c)
 }
 
 static ssize_t sys_t_write(struct stm_data *data, struct stm_output *output,
-			   unsigned int chan, const char *buf, size_t count)
+			   unsigned int chan, const char *buf, size_t count,
+			   struct stm_source_data *source)
 {
 	struct sys_t_output *op = output->pdrv_private;
 	unsigned int c = output->channel + chan;

drivers/hwtracing/stm/stm.h

@@ -96,7 +96,7 @@ struct stm_protocol_driver {
 	const char	*name;
 	ssize_t		(*write)(struct stm_data *data,
 				 struct stm_output *output, unsigned int chan,
-				 const char *buf, size_t count);
+				 const char *buf, size_t count, struct stm_source_data *source);
 	void		(*policy_node_init)(void *arg);
 	int		(*output_open)(void *priv, struct stm_output *output);
 	void		(*output_close)(struct stm_output *output);