stm class: Add source type

Currently kernel HW tracing infrastrtucture and specifically its SyS-T
part treats all source data in the same way. Treating and encoding
different trace data sources differently might allow decoding software
to make use of e.g. ftrace event ids by converting them to a SyS-T
message catalog.

The solution is to keep source type stored within stm_source_data
structure to allow different handling by stm output/protocol.
Currently we only differentiate between STM_USER and STM_FTRACE sources.

Signed-off-by: Mikhail Lappo <[e-mail]>
Signed-off-by: Alexander Shishkin <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/hwtracing/stm/console.c

···
 	.data	= {
 		.name		= "console",
 		.nr_chans	= 1,
+		.type		= STM_USER,
 		.link		= stm_console_link,
 		.unlink		= stm_console_unlink,
 	},

drivers/hwtracing/stm/ftrace.c

···
 	.data	= {
 		.name		= "ftrace",
 		.nr_chans	= STM_FTRACE_NR_CHANNELS,
+		.type		= STM_FTRACE,
 		.link		= stm_ftrace_link,
 		.unlink		= stm_ftrace_unlink,
 	},

drivers/hwtracing/stm/heartbeat.c

···
 		}
 
 		stm_heartbeat[i].data.nr_chans	= 1;
+		stm_heartbeat[i].data.type	= STM_USER;
 		stm_heartbeat[i].data.link	= stm_heartbeat_link;
 		stm_heartbeat[i].data.unlink	= stm_heartbeat_unlink;
 		hrtimer_init(&stm_heartbeat[i].hrtimer, CLOCK_MONOTONIC,

include/linux/stm.h

···
 	STP_PACKET_TIMESTAMPED	= 0x2,
 };
 
+/**
+ * enum stm_source_type - STM source driver
+ * @STM_USER: any STM trace source
+ * @STM_FTRACE: ftrace STM source
+ */
+enum stm_source_type {
+	STM_USER,
+	STM_FTRACE,
+};
+
 struct stp_policy;
 
 struct stm_device;
···
  * @name:	device name, will be used for policy lookup
  * @src:	internal structure, only used by stm class code
  * @nr_chans:	number of channels to allocate
+ * @type:	type of STM source driver represented by stm_source_type
  * @link:	called when this source gets linked to an STM device
  * @unlink:	called when this source is about to get unlinked from its STM
  *
···
 	struct stm_source_device *src;
 	unsigned int		percpu;
 	unsigned int		nr_chans;
+	unsigned int		type;
 	int			(*link)(struct stm_source_data *data);
 	void			(*unlink)(struct stm_source_data *data);
 };