Trace thermal zone temperatures in the LISA kmodule

lisa/_assets/kmodules/lisa/Makefile

@@ -68,7 +68,7 @@ ifneq ($(KERNELRELEASE),)
 
 LISA_KMOD_NAME ?= lisa
 obj-m := $(LISA_KMOD_NAME).o
-$(LISA_KMOD_NAME)-y := main.o tp.o wq.o features.o pixel6.o introspection_data.o
+$(LISA_KMOD_NAME)-y := main.o tp.o wq.o features.o pixel6.o introspection_data.o thermal.o
 
 # -fno-stack-protector is needed to possibly undefined __stack_chk_guard symbol
 ccflags-y := "-I$(MODULE_SRC)" -std=gnu11 -fno-stack-protector -Wno-declaration-after-statement -Wno-error

lisa/_assets/kmodules/lisa/ftrace_events.h

@@ -429,7 +429,7 @@ TRACE_EVENT(lisa__pixel6_emeter,
 	),
 
 	TP_fast_assign(
-		__entry->ts		    = ts;
+		__entry->ts		= ts;
 		__entry->device		= device;
 		__entry->chan		= chan;
 		__entry->value		= value;
@@ -440,6 +440,29 @@ TRACE_EVENT(lisa__pixel6_emeter,
 		  __entry->ts, __entry->device, __entry->chan, __entry->chan_name, __entry->value)
 );
 
+#include <uapi/linux/thermal.h> // THERMAL_NAME_LENGTH
+
+TRACE_EVENT(lisa__thermal,
+	TP_PROTO(u64 ts, int id, int temp, const char *name),
+	TP_ARGS(ts, id, temp, name),
+
+	TP_STRUCT__entry(
+		__field(u64,		ts				)
+		__field(int, 		id				)
+		__field(int,		temp				)
+		__array(char,		name,	THERMAL_NAME_LENGTH	)
+	),
+
+	TP_fast_assign(
+		__entry->ts     = ts;
+		__entry->id	= id;
+		__entry->temp	= temp;
+		strlcpy(__entry->name, name, sizeof(__entry->name));
+	),
+
+	TP_printk("ts=%llu id=%d name=%s temp=%d",
+		  __entry->ts, __entry->id, __entry->name, __entry->temp)
+);
 #endif /* _FTRACE_EVENTS_H */
 
 /* This part must be outside protection */

lisa/_assets/kmodules/lisa/thermal.c

@@ -0,0 +1,170 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/stringify.h>
+#include <linux/thermal.h>
+#include <linux/types.h>
+
+#include "main.h"
+
+#include "features.h"
+#include "ftrace_events.h"
+#include "utils.h"
+#include "wq.h"
+
+/* Millisecond interval for polling temperatures. Clamped to [1,5000]. */
+#ifdef CONFIG_POLL_INTERVAL_MS
+# define POLL_INTERVAL_MS		CLAMP((CONFIG_POLL_INTERVAL_MS), 1, 5000)
+#else
+# define POLL_INTERVAL_MS		100
+#endif /* CONFIG_POLL_INTERVAL_MS */
+
+/** Comma-separted list of names of thermal zones to monitor. */
+#ifdef CONFIG_THERMAL_ZONE_LIST
+static const char *thermal_zone_names[] = {STRINGIFY_ALL(CONFIG_THERMAL_ZONE_LIST)};
+#else
+static const char *thermal_zone_names[] = {"LITTLE","MID","BIG"};
+#endif /* CONFIG_THERMAL_ZONE_LIST */
+
+/* Number of items in THERMAL_ZONE_LIST. */
+#define NUM_THERMAL_ZONES		(ARRAY_SIZE(thermal_zone_names))
+
+#define FEATURE_NAME			lisa__thermal
+#define TEMPERATURE_MIN			-273100
+#define TEMPERATURE_MAX			999999
+
+/* Shorthands for allocators. */
+#define kzalloc_k(N)			(kzalloc((N), GFP_KERNEL))
+#define kcalloc_k(N, SIZE)		(kcalloc((N), (SIZE), GFP_KERNEL))
+
+struct thermal_config {
+	int				temps[NUM_THERMAL_ZONES];
+	struct thermal_zone_device	*devs[NUM_THERMAL_ZONES];
+	struct work_item 		*work;
+};
+
+/* struct thermal_config accessors */
+#define thermal_config_temp(CFG, I)	((CFG)->temps[(I)])
+#define thermal_config_device(CFG, I)	((CFG)->devs[(I)])
+#define trace_ith_tz(CFG, I, TS)				\
+	trace_lisa__thermal(					\
+		(TS),						\
+		thermal_config_device((CFG), (I))->id,		\
+		thermal_config_temp((CFG), (I)),		\
+		thermal_config_device((CFG), (I))->type)
+
+#define NANOS_TO_MILLIS 1000000
+
+static int thermal_worker(void *data)
+{
+	struct thermal_config *config = data;
+	/* Use same timestamp for each TZ to make parsing easier.
+	 * Convert to millis for consistency with lisa__pixel6_emeter.
+	 */
+	u64 ts = ktime_get_real_ns()/NANOS_TO_MILLIS;
+	for (u32 i = 0; i < NUM_THERMAL_ZONES; i++) {
+		struct thermal_zone_device *dev;
+		int temp, ret;
+
+		dev = thermal_config_device(config, i);
+		ret = thermal_zone_get_temp(dev, &temp);
+		if (ret != 0) {
+			pr_err("Could not get temperature for %s: %d\n",
+			       dev->type, ret);
+			continue;
+		}
+
+		temp = CLAMP(temp, TEMPERATURE_MIN, TEMPERATURE_MAX);
+		if (temp != thermal_config_temp(config, i)) {
+			thermal_config_temp(config, i) = temp;
+			trace_ith_tz(config, i, ts);
+		}
+	}
+
+	return WORKER_SAME_DELAY;
+}
+
+static void thermal_config_deinit(struct thermal_config *config)
+{
+	if (!config)
+		return;
+	/* Destroy work first in case the worker is running */
+	destroy_work(config->work);
+	/* Now the worker is stopped */
+	kfree(config);
+}
+
+static int thermal_config_init(
+	struct feature *feature, struct thermal_config **pconfig)
+{
+	int ret = 0;
+	struct thermal_config *config;
+
+	config = kzalloc_k(sizeof(*config));
+	if (!config) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	for (int i = 0; i < NUM_THERMAL_ZONES; i++) {
+		config->devs[i] = thermal_zone_get_zone_by_name(thermal_zone_names[i]);
+		if (config->devs[i] == NULL) {
+			pr_err("No such device: %s\n", thermal_zone_names[i]);
+			return -ENOENT;
+		}
+
+		/* Initialise to an invalid value so the first trace always
+		 * detects the temperature as having changed. */
+		config->temps[i] = THERMAL_TEMP_INVALID;
+	}
+
+out:
+	if (ret != 0) {
+		thermal_config_deinit(config);
+		pr_warn("Initialise thermal zone list failed (err=%d)\n", ret);
+		return ret;
+	}
+
+	*pconfig = config;
+	pr_info("Thermal zone list initialised\n");
+	return ret;
+}
+
+static int thermal_disable(struct feature *feature)
+{
+
+	thermal_config_deinit(feature->data);
+	feature->data = NULL;
+	return DISABLE_FEATURE(__worqueue);
+}
+
+static int thermal_enable(struct feature *feature)
+{
+	struct thermal_config *config;
+	int ret = 0;
+
+	ret = ENABLE_FEATURE(__worqueue);
+	if (ret != 0)
+		return ret;
+
+	ret = thermal_config_init(feature, &config);
+	if (ret != 0)
+		goto out;
+
+	feature->data = config;
+
+	int delay_jiffies = (int)msecs_to_jiffies(POLL_INTERVAL_MS);
+	config->work = start_work(thermal_worker, delay_jiffies, config);
+	if (!config->work) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+out:
+	if (ret != 0)
+		thermal_disable(feature);
+	return ret;
+}
+
+DEFINE_FEATURE(FEATURE_NAME, thermal_enable, thermal_disable);

lisa/_assets/kmodules/lisa/utils.h

@@ -12,4 +12,24 @@
 
 #include "linux/kernel.h"
 
+#define __STRINGIFY_12(X, ...)	__stringify(X), __STRINGIFY_11(__VA_ARGS__)
+#define __STRINGIFY_11(X, ...)	__stringify(X), __STRINGIFY_10(__VA_ARGS__)
+#define __STRINGIFY_10(X, ...)	__stringify(X), __STRINGIFY_9(__VA_ARGS__)
+#define __STRINGIFY_9(X, ...)	__stringify(X), __STRINGIFY_8(__VA_ARGS__)
+#define __STRINGIFY_8(X, ...)	__stringify(X), __STRINGIFY_7(__VA_ARGS__)
+#define __STRINGIFY_7(X, ...)	__stringify(X), __STRINGIFY_6(__VA_ARGS__)
+#define __STRINGIFY_6(X, ...)	__stringify(X), __STRINGIFY_5(__VA_ARGS__)
+#define __STRINGIFY_5(X, ...)	__stringify(X), __STRINGIFY_4(__VA_ARGS__)
+#define __STRINGIFY_4(X, ...)	__stringify(X), __STRINGIFY_3(__VA_ARGS__)
+#define __STRINGIFY_3(X, ...)	__stringify(X), __STRINGIFY_2(__VA_ARGS__)
+#define __STRINGIFY_2(X, ...)	__stringify(X), __STRINGIFY_1(__VA_ARGS__)
+#define __STRINGIFY_1(X)	__stringify(X)
+#define __STRINGIFY_0()
+
+/** Stringify up to 12 args. */
+#define STRINGIFY_ALL(...)	CONCATENATE(__STRINGIFY_, COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__)
+
+/** Clamp X to a value in [A,B]. */
+#define CLAMP(X, A, B)		((X) < (A) ? (A) : ((X) > (B) ? (B) : (X)))
+
 #endif /* _UTILS_H */

lisa/trace.py

@@ -1585,6 +1585,14 @@ class TxtTraceParser(TxtTraceParserBase):
                 'util_avg': _KERNEL_DTYPE['util'],
             },
         ),
+        'lisa__thermal': dict(
+            fields={
+                'ts': 'uint64',
+                'id': 'int32',
+                'temp': 'int32',
+                'name': 'str'
+            }
+        )
     }
 
     @PartialInit.factory