[PATCH v2 2/5] coresight: etm4x: exclude ss_status from drvdata->config

Yeoreum Yun yeoreum.yun at arm.com
Fri Apr 10 00:43:07 PDT 2026


The purpose of TRCSSCSRn register is to show status of
the corresponding Single-shot Comparator Control and input supports.
That means writable field's purpose for reset or restore from idle status
not for configuration.

Therefore, exclude ss_status from drvdata->config, move it to etm4x_caps.
This includes remove TRCSSCRn from configurable item and
remove saving in etm4_disable_hw().

Signed-off-by: Yeoreum Yun <yeoreum.yun at arm.com>
---
 .../hwtracing/coresight/coresight-etm4x-cfg.c  |  1 -
 .../hwtracing/coresight/coresight-etm4x-core.c | 18 +++++-------------
 .../coresight/coresight-etm4x-sysfs.c          |  7 ++-----
 drivers/hwtracing/coresight/coresight-etm4x.h  |  3 ++-
 4 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
index c302072b293a..d14d7c8a23e5 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
@@ -86,7 +86,6 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
 		off_mask =  (offset & GENMASK(11, 5));
 		do {
 			CHECKREGIDX(TRCSSCCRn(0), ss_ctrl, idx, off_mask);
-			CHECKREGIDX(TRCSSCSRn(0), ss_status, idx, off_mask);
 			CHECKREGIDX(TRCSSPCICRn(0), ss_pe_cmp, idx, off_mask);
 		} while (0);
 	} else if ((offset >= TRCCIDCVRn(0)) && (offset <= TRCVMIDCVRn(7))) {
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 6443f3717b37..b7abb171f523 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -91,7 +91,7 @@ static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
 	const struct etmv4_caps *caps = &drvdata->caps;
 
 	return (n < caps->nr_ss_cmp) && caps->nr_pe &&
-	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
+	       (caps->ss_status[n] & TRCSSCSRn_PC);
 }
 
 u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
@@ -571,11 +571,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
 
 	for (i = 0; i < caps->nr_ss_cmp; i++) {
-		/* always clear status bit on restart if using single-shot */
-		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
-			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
 		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
-		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
+		/* always clear status bit on restart if using single-shot */
+		etm4x_relaxed_write32(csa, caps->ss_status[i], TRCSSCSRn(i));
 		if (etm4x_sspcicrn_present(drvdata, i))
 			etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
 	}
@@ -1053,12 +1051,6 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
 
 	etm4_disable_trace_unit(drvdata);
 
-	/* read the status of the single shot comparators */
-	for (i = 0; i < caps->nr_ss_cmp; i++) {
-		config->ss_status[i] =
-			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
-	}
-
 	/* read back the current counter values */
 	for (i = 0; i < caps->nr_cntr; i++) {
 		config->cntr_val[i] =
@@ -1501,8 +1493,8 @@ static void etm4_init_arch_data(void *info)
 	 */
 	caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
 	for (i = 0; i < caps->nr_ss_cmp; i++) {
-		drvdata->config.ss_status[i] =
-			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
+		caps->ss_status[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
+		caps->ss_status[i] &= ~(TRCSSCSRn_STATUS | TRCSSCSRn_PENDING);
 	}
 	/* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */
 	caps->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index 3d5f343130bd..c794fc9de5b6 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -1832,8 +1832,6 @@ static ssize_t sshot_ctrl_store(struct device *dev,
 	raw_spin_lock(&drvdata->spinlock);
 	idx = config->ss_idx;
 	config->ss_ctrl[idx] = FIELD_PREP(TRCSSCCRn_SAC_ARC_RST_MASK, val);
-	/* must clear bit 31 in related status register on programming */
-	config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
 	raw_spin_unlock(&drvdata->spinlock);
 	return size;
 }
@@ -1844,10 +1842,11 @@ static ssize_t sshot_status_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	raw_spin_lock(&drvdata->spinlock);
-	val = config->ss_status[config->ss_idx];
+	val = caps->ss_status[config->ss_idx];
 	raw_spin_unlock(&drvdata->spinlock);
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
@@ -1882,8 +1881,6 @@ static ssize_t sshot_pe_ctrl_store(struct device *dev,
 	raw_spin_lock(&drvdata->spinlock);
 	idx = config->ss_idx;
 	config->ss_pe_cmp[idx] = FIELD_PREP(TRCSSPCICRn_PC_MASK, val);
-	/* must clear bit 31 in related status register on programming */
-	config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
 	raw_spin_unlock(&drvdata->spinlock);
 	return size;
 }
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 3e20561672dc..57508d301327 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -213,6 +213,7 @@
 #define TRCACATRn_EXLEVEL_MASK			GENMASK(14, 8)
 
 #define TRCSSCSRn_STATUS			BIT(31)
+#define TRCSSCSRn_PENDING			BIT(30)
 #define TRCSSCCRn_SAC_ARC_RST_MASK		GENMASK(24, 0)
 
 #define TRCSSPCICRn_PC_MASK			GENMASK(7, 0)
@@ -898,6 +899,7 @@ struct etmv4_caps {
 	bool	atbtrig : 1;
 	bool	lpoverride : 1;
 	bool	skip_power_up : 1;
+	u32	ss_status[ETM_MAX_SS_CMP];
 };
 
 /**
@@ -976,7 +978,6 @@ struct etmv4_config {
 	u32				res_ctrl[ETM_MAX_RES_SEL]; /* TRCRSCTLRn */
 	u8				ss_idx;
 	u32				ss_ctrl[ETM_MAX_SS_CMP];
-	u32				ss_status[ETM_MAX_SS_CMP];
 	u32				ss_pe_cmp[ETM_MAX_SS_CMP];
 	u8				addr_idx;
 	u64				addr_val[ETM_MAX_SINGLE_ADDR_CMP];
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}




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