[PATCH v1 2/3] coresight: Add reserve trace id support

[Mao Jinlong]

Dynamic trace id was introduced in coresight subsystem so trace id is
allocated dynamically. However, some hardware ATB source has static trace
id and it cannot be changed via software programming. Reserve trace id
for this kind of hardware source.

Signed-off-by: Mao Jinlong <quic_jinlmao at quicinc.com>
---
 .../hwtracing/coresight/coresight-platform.c  | 26 +++++++++++++++++++
 .../hwtracing/coresight/coresight-trace-id.c  | 24 +++++++++++++++++
 .../hwtracing/coresight/coresight-trace-id.h  | 11 ++++++++
 include/linux/coresight.h                     |  1 +
 4 files changed, 62 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index 9d550f5697fa..d3e22a2608df 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -183,6 +183,17 @@ static int of_coresight_get_cpu(struct device *dev)
 	return cpu;
 }
 
+/*
+ * of_coresight_get_trace_id: Get the atid of a source device.
+ *
+ * Returns 0 on success.
+ */
+static int of_coresight_get_trace_id(struct device *dev, u32 *id)
+{
+
+	return of_property_read_u32(dev->of_node, "trace-id", id);
+}
+
 /*
  * of_coresight_parse_endpoint : Parse the given output endpoint @ep
  * and fill the connection information in @pdata->out_conns
@@ -315,6 +326,12 @@ static inline int of_coresight_get_cpu(struct device *dev)
 {
 	return -ENODEV;
 }
+
+static int of_coresight_get_trace_id(struct device *dev, u32 *id)
+{
+	return -ENODEV;
+}
+
 #endif
 
 #ifdef CONFIG_ACPI
@@ -794,6 +811,15 @@ int coresight_get_cpu(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(coresight_get_cpu);
 
+int coresight_get_trace_id(struct device *dev, u32 *id)
+{
+	if (!is_of_node(dev->fwnode))
+		return -EINVAL;
+
+	return of_coresight_get_trace_id(dev, id);
+}
+EXPORT_SYMBOL_GPL(coresight_get_trace_id);
+
 struct coresight_platform_data *
 coresight_get_platform_data(struct device *dev)
 {
diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
index af5b4ef59cea..536a34e9de6f 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.c
+++ b/drivers/hwtracing/coresight/coresight-trace-id.c
@@ -110,6 +110,24 @@ static int coresight_trace_id_alloc_new_id(struct coresight_trace_id_map *id_map
 	return id;
 }
 
+static int coresight_trace_id_set(int id, struct coresight_trace_id_map *id_map)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&id_map_lock, flags);
+
+	if (WARN(!IS_VALID_CS_TRACE_ID(id), "Invalid Trace ID %d\n", id))
+		return -EINVAL;
+	if (WARN(test_bit(id, id_map->used_ids), "ID is already used: %d\n", id))
+		return -EINVAL;
+	set_bit(id, id_map->used_ids);
+
+	DUMP_ID_MAP(id_map);
+
+	spin_unlock_irqrestore(&id_map_lock, flags);
+	return 0;
+}
+
 static void coresight_trace_id_free(int id, struct coresight_trace_id_map *id_map)
 {
 	if (WARN(!IS_VALID_CS_TRACE_ID(id), "Invalid Trace ID %d\n", id))
@@ -275,6 +293,12 @@ int coresight_trace_id_get_system_id(void)
 }
 EXPORT_SYMBOL_GPL(coresight_trace_id_get_system_id);
 
+int coresight_trace_id_reserve_system_id(int id)
+{
+	return coresight_trace_id_set(id, &id_map_default);
+}
+EXPORT_SYMBOL_GPL(coresight_trace_id_reserve_system_id);
+
 void coresight_trace_id_put_system_id(int id)
 {
 	coresight_trace_id_map_put_system_id(&id_map_default, id);
diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h
index 3797777d367e..255716887051 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.h
+++ b/drivers/hwtracing/coresight/coresight-trace-id.h
@@ -122,6 +122,17 @@ int coresight_trace_id_read_cpu_id(int cpu);
  */
 int coresight_trace_id_get_system_id(void);
 
+/**
+ * Reserve trace id for a system component.
+ *
+ * Reserve the trace id if system component needs a static id for the trace.
+ *
+ * @id: value of trace ID.
+ *
+ * return: 0 if reserve successfully or -EINVAL if fail.
+ */
+int coresight_trace_id_reserve_system_id(int id);
+
 /**
  * Release an allocated system trace ID.
  *
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index f09ace92176e..f65dc20ca76e 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -643,6 +643,7 @@ void coresight_relaxed_write64(struct coresight_device *csdev,
 void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset);
 
 extern int coresight_get_cpu(struct device *dev);
+extern int coresight_get_trace_id(struct device *dev, u32 *id);
 
 struct coresight_platform_data *coresight_get_platform_data(struct device *dev);
 struct coresight_connection *
-- 
2.41.0