linux-kernel - [PATCH v6 01/26] coresight: etm4x: Handle access to TRCSSPCICRn

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Date:   Thu,  7 Jan 2021 12:38:34 +0000
From:   Suzuki K Poulose <suzuki.poulose@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, coresight@...ts.linaro.org,
        mathieu.poirier@...aro.org, leo.yan@...aro.org,
        mike.leach@...aro.org, anshuman.khandual@....com,
        Suzuki K Poulose <suzuki.poulose@....com>
Subject: [PATCH v6 01/26] coresight: etm4x: Handle access to TRCSSPCICRn

TRCSSPCICR<n> is present only if all of the following are true:
	TRCIDR4.NUMSSCC > n.
	TRCIDR4.NUMPC > 0b0000 .
	TRCSSCSR<n>.PC == 0b1

Add a helper function to check all the conditions.

Cc: Mike Leach <mike.leach@...aro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@...aro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
---
Changes since v3:
 - Check for TRCSSCSRn.PC too.  (Mathieu)
 - Moved into a helper for easy reuse.
---
 .../coresight/coresight-etm4x-core.c          | 29 +++++++++++++++----
 drivers/hwtracing/coresight/coresight-etm4x.h |  2 ++
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index b20b6ff17cf6..76526679b998 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -59,6 +59,22 @@ static u64 etm4_get_access_type(struct etmv4_config *config);
 
 static enum cpuhp_state hp_online;
 
+/*
+ * Check if TRCSSPCICRn(i) is implemented for a given instance.
+ *
+ * TRCSSPCICRn is implemented only if :
+ *	TRCSSPCICR<n> is present only if all of the following are true:
+ *		TRCIDR4.NUMSSCC > n.
+ *		TRCIDR4.NUMPC > 0b0000 .
+ *		TRCSSCSR<n>.PC == 0b1
+ */
+static inline bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
+{
+	return (n < drvdata->nr_ss_cmp) &&
+	       drvdata->nr_pe &&
+	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
+}
+
 static void etm4_os_unlock(struct etmv4_drvdata *drvdata)
 {
 	/* Writing 0 to TRCOSLAR unlocks the trace registers */
@@ -270,8 +286,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 			       drvdata->base + TRCSSCCRn(i));
 		writel_relaxed(config->ss_status[i],
 			       drvdata->base + TRCSSCSRn(i));
-		writel_relaxed(config->ss_pe_cmp[i],
-			       drvdata->base + TRCSSPCICRn(i));
+		if (etm4x_sspcicrn_present(drvdata, i))
+			writel_relaxed(config->ss_pe_cmp[i],
+				       drvdata->base + TRCSSPCICRn(i));
 	}
 	for (i = 0; i < drvdata->nr_addr_cmp; i++) {
 		writeq_relaxed(config->addr_val[i],
@@ -1324,7 +1341,8 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
 		state->trcssccr[i] = readl(drvdata->base + TRCSSCCRn(i));
 		state->trcsscsr[i] = readl(drvdata->base + TRCSSCSRn(i));
-		state->trcsspcicr[i] = readl(drvdata->base + TRCSSPCICRn(i));
+		if (etm4x_sspcicrn_present(drvdata, i))
+			state->trcsspcicr[i] = readl(drvdata->base + TRCSSPCICRn(i));
 	}
 
 	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
@@ -1440,8 +1458,9 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 			       drvdata->base + TRCSSCCRn(i));
 		writel_relaxed(state->trcsscsr[i],
 			       drvdata->base + TRCSSCSRn(i));
-		writel_relaxed(state->trcsspcicr[i],
-			       drvdata->base + TRCSSPCICRn(i));
+		if (etm4x_sspcicrn_present(drvdata, i))
+			writel_relaxed(state->trcsspcicr[i],
+				       drvdata->base + TRCSSPCICRn(i));
 	}
 
 	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 3dd3e0633328..80e480c7fe5c 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -179,6 +179,8 @@
 #define TRCSTATR_PMSTABLE_BIT		1
 #define ETM_DEFAULT_ADDR_COMP		0
 
+#define TRCSSCSRn_PC			BIT(3)
+
 /* PowerDown Control Register bits */
 #define TRCPDCR_PU			BIT(3)
 
-- 
2.24.1