linux-kernel - [PATCH] coresight: trbe: Directly use ID_AA64DFR0_EL1_TraceBuffer

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Date:   Wed,  2 Aug 2023 12:06:58 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-arm-kernel@...ts.infradead.org, suzuki.poulose@....com
Cc:     Anshuman Khandual <anshuman.khandual@....com>,
        Mike Leach <mike.leach@...aro.org>,
        James Clark <james.clark@....com>,
        Leo Yan <leo.yan@...aro.org>, coresight@...ts.linaro.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] coresight: trbe: Directly use ID_AA64DFR0_EL1_TraceBuffer_IMP

is_trbe_available() checks for the TRBE support via extracting TraceBuffer
field value from ID_AA64DFR0_EL1, and ensures that it is implemented. This
replaces the open encoding '0b0001' with 'ID_AA64DFR0_EL1_TraceBuffer_IMP'
which is now available via sysreg tools. Functional change is not intended.

Cc: Suzuki K Poulose <suzuki.poulose@....com>
Cc: Mike Leach <mike.leach@...aro.org>
Cc: James Clark <james.clark@....com>
Cc: Leo Yan <leo.yan@...aro.org>
Cc: coresight@...ts.linaro.org
Cc: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
---
 drivers/hwtracing/coresight/coresight-trbe.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.h b/drivers/hwtracing/coresight/coresight-trbe.h
index 94e67009848a..ebb9108d8e24 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.h
+++ b/drivers/hwtracing/coresight/coresight-trbe.h
@@ -24,7 +24,7 @@ static inline bool is_trbe_available(void)
 	unsigned int trbe = cpuid_feature_extract_unsigned_field(aa64dfr0,
 								 ID_AA64DFR0_EL1_TraceBuffer_SHIFT);
 
-	return trbe >= 0b0001;
+	return trbe >= ID_AA64DFR0_EL1_TraceBuffer_IMP;
 }
 
 static inline bool is_trbe_enabled(void)
-- 
2.25.1