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Subject[PATCH v6 03/21] perf arm-spe: Refactor payload size calculation
Date
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
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