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From:   Leo Yan <leo.yan@linaro.org>
To:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Andre Przywara <andre.przywara@arm.com>,
        Dave Martin <Dave.Martin@arm.com>,
        James Clark <james.clark@arm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Al Grant <Al.Grant@arm.com>, Wei Li <liwei391@huawei.com>,
        linux-kernel@vger.kernel.org
Cc:     Leo Yan <leo.yan@linaro.org>
Subject: [PATCH v7 03/22] perf arm-spe: Refactor payload size calculation
Date:   Fri,  6 Nov 2020 09:41:17 +0800
Message-Id: <20201106014136.14103-4-leo.yan@linaro.org>
In-Reply-To: <20201106014136.14103-1-leo.yan@linaro.org>
References: <20201106014136.14103-1-leo.yan@linaro.org>
Precedence: bulk

This patch defines macro to extract "sz" field from header, and renames
the function payloadlen() to arm_spe_payload_len().

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
index 7c7b5eb09fba..06b3eec4494e 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
@@ -69,22 +69,22 @@ const char *arm_spe_pkt_name(enum arm_spe_pkt_type type)
 	return arm_spe_packet_name[type];
 }
 
-/* return ARM SPE payload size from its encoding,
- * which is in bits 5:4 of the byte.
- * 00 : byte
- * 01 : halfword (2)
- * 10 : word (4)
- * 11 : doubleword (8)
+/*
+ * Extracts the field "sz" from header bits and converts to bytes:
+ *   00 : byte (1)
+ *   01 : halfword (2)
+ *   10 : word (4)
+ *   11 : doubleword (8)
  */
-static int payloadlen(unsigned char byte)
+static unsigned int arm_spe_payload_len(unsigned char hdr)
 {
-	return 1 << ((byte & 0x30) >> 4);
+	return 1U << ((hdr & GENMASK_ULL(5, 4)) >> 4);
 }
 
 static int arm_spe_get_payload(const unsigned char *buf, size_t len,
 			       struct arm_spe_pkt *packet)
 {
-	size_t payload_len = payloadlen(buf[0]);
+	size_t payload_len = arm_spe_payload_len(buf[0]);
 
 	if (len < 1 + payload_len)
 		return ARM_SPE_NEED_MORE_BYTES;
-- 
2.17.1