[PATCH RFC 08/15] coresight: tmc-etr: add function to register catu ops

[Mian Yousaf Kaukab]

Make etr_catu_buf_ops static. Instead of directly accessing it in
etr_buf_ops[], add a function to let catu driver register the ops at
runtime. Break circular dependency between tmc-etr and catu drivers.

Signed-off-by: Mian Yousaf Kaukab <ykaukab@xxxxxxx>
---
 drivers/hwtracing/coresight/coresight-catu.c    |  4 +++-
 drivers/hwtracing/coresight/coresight-catu.h    |  2 --
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 17 +++++++++++++++--
 drivers/hwtracing/coresight/coresight-tmc.h     |  3 +++
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
index 6fc76b776744..6c77ccc04842 100644
--- a/drivers/hwtracing/coresight/coresight-catu.c
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -359,7 +359,7 @@ static int catu_alloc_etr_buf(struct tmc_drvdata *tmc_drvdata,
 	return 0;
 }
 
-const struct etr_buf_operations etr_catu_buf_ops = {
+static const struct etr_buf_operations etr_catu_buf_ops = {
 	.alloc = catu_alloc_etr_buf,
 	.free = catu_free_etr_buf,
 	.sync = catu_sync_etr_buf,
@@ -559,6 +559,8 @@ static int catu_probe(struct amba_device *adev, const struct amba_id *id)
 	catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
 	catu_desc.ops = &catu_ops;
 
+	tmc_etr_set_catu_ops(&etr_catu_buf_ops);
+
 	drvdata->csdev = coresight_register(&catu_desc);
 	if (IS_ERR(drvdata->csdev))
 		ret = PTR_ERR(drvdata->csdev);
diff --git a/drivers/hwtracing/coresight/coresight-catu.h b/drivers/hwtracing/coresight/coresight-catu.h
index 80ceee3c739c..6160c2d75a56 100644
--- a/drivers/hwtracing/coresight/coresight-catu.h
+++ b/drivers/hwtracing/coresight/coresight-catu.h
@@ -108,6 +108,4 @@ static inline bool coresight_is_catu_device(struct coresight_device *csdev)
 	return true;
 }
 
-extern const struct etr_buf_operations etr_catu_buf_ops;
-
 #endif
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 625882bc8b08..5b2a515af1ae 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -788,10 +788,23 @@ static inline void tmc_etr_disable_catu(struct tmc_drvdata *drvdata)
 static const struct etr_buf_operations *etr_buf_ops[] = {
 	[ETR_MODE_FLAT] = &etr_flat_buf_ops,
 	[ETR_MODE_ETR_SG] = &etr_sg_buf_ops,
-	[ETR_MODE_CATU] = IS_ENABLED(CONFIG_CORESIGHT_CATU)
-						? &etr_catu_buf_ops : NULL,
+	[ETR_MODE_CATU] = NULL,
 };
 
+void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu)
+{
+	etr_buf_ops[ETR_MODE_CATU] = catu;
+}
+EXPORT_SYMBOL_GPL(tmc_etr_set_catu_ops);
+
+void tmc_etr_remove_catu_ops(void)
+{
+	etr_buf_ops[ETR_MODE_CATU] = NULL;
+	/* TODO: cleanup old etr_buf->ops and anything inflight */
+	wmb();
+}
+EXPORT_SYMBOL_GPL(tmc_etr_remove_catu_ops);
+
 static inline int tmc_etr_mode_alloc_buf(int mode,
 					 struct tmc_drvdata *drvdata,
 					 struct etr_buf *etr_buf, int node,
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 71de978575f3..db431e230a40 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -325,4 +325,7 @@ tmc_sg_table_buf_size(struct tmc_sg_table *sg_table)
 
 struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);
 
+void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu);
+void tmc_etr_remove_catu_ops(void);
+
 #endif
-- 
2.16.4