linux-kernel - [PATCH 7/8] coresight: cti: Remove hw

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Message-Id: <20260209-arm_coresight_cti_refactor_v1-v1-7-db71ab4d200b@arm.com>
Date: Mon, 09 Feb 2026 18:01:17 +0000
From: Leo Yan <leo.yan@....com>
To: Suzuki K Poulose <suzuki.poulose@....com>, 
 Mike Leach <mike.leach@....com>, James Clark <james.clark@...aro.org>, 
 Alexander Shishkin <alexander.shishkin@...ux.intel.com>, 
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
 Mathieu Poirier <mathieu.poirier@...aro.org>, 
 Tingwei Zhang <quic_tingwei@...cinc.com>, 
 Yingchao Deng <yingchao.deng@....qualcomm.com>, 
 Jie Gan <jie.gan@....qualcomm.com>
Cc: coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org, 
 linux-kernel@...r.kernel.org, Leo Yan <leo.yan@....com>
Subject: [PATCH 7/8] coresight: cti: Remove hw_enabled flag

The enable_req_count field already tracks whether the CTI device is
enabled.  A non-zero value indicates that the device is active, the
hw_enabled flag is redundant if so.

Remove hw_enabled and update cti_is_active() to check enable_req_count.
Replace open-coded enable_req_count checks with cti_is_active().

Signed-off-by: Leo Yan <leo.yan@....com>
---
 drivers/hwtracing/coresight/coresight-cti-core.c  | 11 ++---------
 drivers/hwtracing/coresight/coresight-cti-sysfs.c |  2 +-
 drivers/hwtracing/coresight/coresight-cti.h       |  4 +---
 3 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index 3b3b851a018851a8656eba64e638c61f3d04b99f..a7acee27d0aa2c842733f62b7ff88a4c296b51cc 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -90,7 +90,7 @@ static int cti_enable_hw(struct cti_drvdata *drvdata)
 	guard(raw_spinlock_irqsave)(&drvdata->spinlock);
 
 	/* no need to do anything if enabled */
-	if (config->hw_enabled)
+	if (cti_is_active(config))
 		goto cti_state_unchanged;
 
 	/* claim the device */
@@ -100,8 +100,6 @@ static int cti_enable_hw(struct cti_drvdata *drvdata)
 
 	cti_write_all_hw_regs(drvdata);
 
-	config->hw_enabled = true;
-
 cti_state_unchanged:
 	drvdata->config.enable_req_count++;
 	return 0;
@@ -116,22 +114,17 @@ static int cti_disable_hw(struct cti_drvdata *drvdata)
 	guard(raw_spinlock_irqsave)(&drvdata->spinlock);
 
 	/* don't allow negative refcounts, return an error */
-	if (!drvdata->config.enable_req_count)
+	if (!cti_is_active(config))
 		return -EINVAL;
 
 	/* check refcount - disable on 0 */
 	if (--drvdata->config.enable_req_count > 0)
 		return 0;
 
-	/* no need to do anything if disabled */
-	if (!config->hw_enabled)
-		return 0;
-
 	CS_UNLOCK(drvdata->base);
 
 	/* disable CTI */
 	writel_relaxed(0, drvdata->base + CTICONTROL);
-	config->hw_enabled = false;
 
 	coresight_disclaim_device_unlocked(csdev);
 	CS_LOCK(drvdata->base);
diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 9ab586a5c9a4fd2a64c542aaaaa625e2299edd62..9ef44956ebdc7781717d773fa014165989df2048 100644
--- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
@@ -84,7 +84,7 @@ static ssize_t enable_show(struct device *dev,
 	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
 
 	scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
-		enable_req = drvdata->config.enable_req_count;
+		enable_req = cti_is_active(&drvdata->config);
 
 	return sprintf(buf, "%d\n", !!enable_req);
 }
diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
index c858847a5b80036fb48180ff7fbbfe684028cb89..fbb48eb5b0b6a571235d7fecb2c13fc294d8ba50 100644
--- a/drivers/hwtracing/coresight/coresight-cti.h
+++ b/drivers/hwtracing/coresight/coresight-cti.h
@@ -121,7 +121,6 @@ struct cti_device {
  * @nr_ctm_channels: number of available CTM channels - from ID register.
  * @asicctl_impl: true if asicctl is implemented.
  * @enable_req_count: CTI is enabled alongside >=1 associated devices.
- * @hw_enabled: true if hw is currently enabled.
  * @trig_in_use: bitfield of in triggers registered as in use.
  * @trig_out_use: bitfield of out triggers registered as in use.
  * @trig_out_filter: bitfield of out triggers that are blocked if filter
@@ -144,7 +143,6 @@ struct cti_config {
 
 	/* cti enable control */
 	int enable_req_count;
-	bool hw_enabled;
 
 	/* registered triggers and filtering */
 	u32 trig_in_use;
@@ -238,7 +236,7 @@ const char *cti_plat_get_node_name(struct fwnode_handle *fwnode);
 /* Check if a cti device is enabled */
 static inline bool cti_is_active(struct cti_config *cfg)
 {
-	return cfg->hw_enabled;
+	return !!cfg->enable_req_count;
 }
 
 #endif  /* _CORESIGHT_CORESIGHT_CTI_H */

-- 
2.34.1