[3/9] coresight: change coresight_trace_id_map's lock type to raw_spinlock_t

Commit Message

Yeoreum Yun Nov. 25, 2024, 9:48 a.m. UTC

From: Levi Yun <[e-mail]>

coresight_trace_id_map->lock can be acquired while coresight devices'
drvdata_lock.

But the drvdata_lock can be raw_spinlock_t (i.e) coresight-etm4x.

To address this, change type of coresight_trace_id_map->lock to
raw_spinlock_t

Signed-off-by: Yeoreum Yun <[e-mail]>
---
 drivers/hwtracing/coresight/coresight-core.c  |  2 +-
 .../hwtracing/coresight/coresight-trace-id.c  | 93 +++++++++----------
 include/linux/coresight.h                     |  2 +-
 3 files changed, 44 insertions(+), 53 deletions(-)

Patch

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index ea38ecf26fcb..cc2d87b2f248 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1164,7 +1164,7 @@  struct coresight_device *coresight_register(struct coresight_desc *desc)
 
 	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
 	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
-		spin_lock_init(&csdev->perf_sink_id_map.lock);
+		raw_spin_lock_init(&csdev->perf_sink_id_map.lock);
 		csdev->perf_sink_id_map.cpu_map = alloc_percpu(atomic_t);
 		if (!csdev->perf_sink_id_map.cpu_map) {
 			kfree(csdev);
diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
index d98e12cb30ec..1818a353ac5f 100644
--- a/drivers/hwtracing/coresight/coresight-trace-id.c
+++ b/drivers/hwtracing/coresight/coresight-trace-id.c
@@ -16,7 +16,7 @@ 
 static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0);
 static struct coresight_trace_id_map id_map_default = {
 	.cpu_map = &id_map_default_cpu_ids,
-	.lock = __SPIN_LOCK_UNLOCKED(id_map_default.lock)
+	.lock = __RAW_SPIN_LOCK_UNLOCKED(id_map_default.lock)
 };
 
 /* #define TRACE_ID_DEBUG 1 */
@@ -118,50 +118,46 @@  static void coresight_trace_id_free(int id, struct coresight_trace_id_map *id_ma
  */
 static void coresight_trace_id_release_all(struct coresight_trace_id_map *id_map)
 {
-	unsigned long flags;
 	int cpu;
 
-	spin_lock_irqsave(&id_map->lock, flags);
-	bitmap_zero(id_map->used_ids, CORESIGHT_TRACE_IDS_MAX);
-	for_each_possible_cpu(cpu)
-		atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
-	spin_unlock_irqrestore(&id_map->lock, flags);
+	scoped_guard(raw_spinlock_irqsave, &id_map->lock) {
+		bitmap_zero(id_map->used_ids, CORESIGHT_TRACE_IDS_MAX);
+		for_each_possible_cpu(cpu)
+			atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
+	}
+
 	DUMP_ID_MAP(id_map);
 }
 
 static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
 {
-	unsigned long flags;
 	int id;
 
-	spin_lock_irqsave(&id_map->lock, flags);
-
-	/* check for existing allocation for this CPU */
-	id = _coresight_trace_id_read_cpu_id(cpu, id_map);
-	if (id)
-		goto get_cpu_id_out_unlock;
-
-	/*
-	 * Find a new ID.
-	 *
-	 * Use legacy values where possible in the dynamic trace ID allocator to
-	 * allow older tools to continue working if they are not upgraded at the
-	 * same time as the kernel drivers.
-	 *
-	 * If the generated legacy ID is invalid, or not available then the next
-	 * available dynamic ID will be used.
-	 */
-	id = coresight_trace_id_alloc_new_id(id_map,
-					     CORESIGHT_LEGACY_CPU_TRACE_ID(cpu),
-					     false);
-	if (!IS_VALID_CS_TRACE_ID(id))
-		goto get_cpu_id_out_unlock;
-
-	/* allocate the new id to the cpu */
-	atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);
+	scoped_guard(raw_spinlock_irqsave, &id_map->lock) {
+		/* check for existing allocation for this CPU */
+		id = _coresight_trace_id_read_cpu_id(cpu, id_map);
+		if (id)
+			return id;
 
-get_cpu_id_out_unlock:
-	spin_unlock_irqrestore(&id_map->lock, flags);
+		/*
+		 * Find a new ID.
+		 *
+		 * Use legacy values where possible in the dynamic trace ID allocator to
+		 * allow older tools to continue working if they are not upgraded at the
+		 * same time as the kernel drivers.
+		 *
+		 * If the generated legacy ID is invalid, or not available then the next
+		 * available dynamic ID will be used.
+		 */
+		id = coresight_trace_id_alloc_new_id(id_map,
+						     CORESIGHT_LEGACY_CPU_TRACE_ID(cpu),
+						     false);
+		if (!IS_VALID_CS_TRACE_ID(id))
+			return id;
+
+		/* allocate the new id to the cpu */
+		atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);
+	}
 
 	DUMP_ID_CPU(cpu, id);
 	DUMP_ID_MAP(id_map);
@@ -170,7 +166,6 @@  static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map
 
 static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
 {
-	unsigned long flags;
 	int id;
 
 	/* check for existing allocation for this CPU */
@@ -178,25 +173,23 @@  static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_ma
 	if (!id)
 		return;
 
-	spin_lock_irqsave(&id_map->lock, flags);
-
-	coresight_trace_id_free(id, id_map);
-	atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
+	scoped_guard(raw_spinlock_irqsave, &id_map->lock) {
+		coresight_trace_id_free(id, id_map);
+		atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
+	}
 
-	spin_unlock_irqrestore(&id_map->lock, flags);
 	DUMP_ID_CPU(cpu, id);
 	DUMP_ID_MAP(id_map);
 }
 
 static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map)
 {
-	unsigned long flags;
 	int id;
 
-	spin_lock_irqsave(&id_map->lock, flags);
-	/* prefer odd IDs for system components to avoid legacy CPU IDS */
-	id = coresight_trace_id_alloc_new_id(id_map, 0, true);
-	spin_unlock_irqrestore(&id_map->lock, flags);
+	scoped_guard(raw_spinlock_irqsave, &id_map->lock) {
+		/* prefer odd IDs for system components to avoid legacy CPU IDS */
+		id = coresight_trace_id_alloc_new_id(id_map, 0, true);
+	}
 
 	DUMP_ID(id);
 	DUMP_ID_MAP(id_map);
@@ -205,11 +198,9 @@  static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *i
 
 static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *id_map, int id)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&id_map->lock, flags);
-	coresight_trace_id_free(id, id_map);
-	spin_unlock_irqrestore(&id_map->lock, flags);
+	scoped_guard(raw_spinlock_irqsave, &id_map->lock) {
+		coresight_trace_id_free(id, id_map);
+	}
 
 	DUMP_ID(id);
 	DUMP_ID_MAP(id_map);
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 924b58c343b3..6446ca1f09d8 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -233,7 +233,7 @@  struct coresight_trace_id_map {
 	DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
 	atomic_t __percpu *cpu_map;
 	atomic_t perf_cs_etm_session_active;
-	spinlock_t lock;
+	raw_spinlock_t lock;
 };
 
 /**