linux-kernel - [PATCH v1 1/3] perf cs-etm: Refactor instruction size handling

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Date:   Fri, 30 Aug 2019 14:24:19 +0800
From:   Leo Yan <leo.yan@...aro.org>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mathieu Poirier <mathieu.poirier@...aro.org>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Mike Leach <mike.leach@...aro.org>,
        Robert Walker <Robert.Walker@....com>,
        Adrian Hunter <adrian.hunter@...el.com>
Cc:     Leo Yan <leo.yan@...aro.org>
Subject: [PATCH v1 1/3] perf cs-etm: Refactor instruction size handling

There has several code pieces need to know the instruction size, but
now every place calculates the instruction size separately.

This patch refactors to create a new function cs_etm__instr_size() as
a central place to analyze the instruction length based on ISA type
and instruction value.

Signed-off-by: Leo Yan <leo.yan@...aro.org>
---
 tools/perf/util/cs-etm.c | 44 +++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index b3a5daaf1a8f..882a0718033d 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -914,6 +914,26 @@ static inline int cs_etm__t32_instr_size(struct cs_etm_queue *etmq,
 	return ((instrBytes[1] & 0xF8) >= 0xE8) ? 4 : 2;
 }
 
+static inline int cs_etm__instr_size(struct cs_etm_queue *etmq,
+				     u8 trace_chan_id,
+				     enum cs_etm_isa isa,
+				     u64 addr)
+{
+	int insn_len;
+
+	/*
+	 * T32 instruction size might be 32-bit or 16-bit, decide by calling
+	 * cs_etm__t32_instr_size().
+	 */
+	if (isa == CS_ETM_ISA_T32)
+		insn_len = cs_etm__t32_instr_size(etmq, trace_chan_id, addr);
+	/* Otherwise, A64 and A32 instruction size are always 32-bit. */
+	else
+		insn_len = 4;
+
+	return insn_len;
+}
+
 static inline u64 cs_etm__first_executed_instr(struct cs_etm_packet *packet)
 {
 	/* Returns 0 for the CS_ETM_DISCONTINUITY packet */
@@ -938,19 +958,23 @@ static inline u64 cs_etm__instr_addr(struct cs_etm_queue *etmq,
 				     const struct cs_etm_packet *packet,
 				     u64 offset)
 {
+	int insn_len;
+
 	if (packet->isa == CS_ETM_ISA_T32) {
 		u64 addr = packet->start_addr;
 
 		while (offset > 0) {
-			addr += cs_etm__t32_instr_size(etmq,
-						       trace_chan_id, addr);
+			addr += cs_etm__instr_size(etmq, trace_chan_id,
+						   packet->isa, addr);
 			offset--;
 		}
 		return addr;
 	}
 
-	/* Assume a 4 byte instruction size (A32/A64) */
-	return packet->start_addr + offset * 4;
+	/* Return instruction size for A32/A64 */
+	insn_len = cs_etm__instr_size(etmq, trace_chan_id,
+				      packet->isa, packet->start_addr);
+	return packet->start_addr + offset * insn_len;
 }
 
 static void cs_etm__update_last_branch_rb(struct cs_etm_queue *etmq,
@@ -1090,16 +1114,8 @@ static void cs_etm__copy_insn(struct cs_etm_queue *etmq,
 		return;
 	}
 
-	/*
-	 * T32 instruction size might be 32-bit or 16-bit, decide by calling
-	 * cs_etm__t32_instr_size().
-	 */
-	if (packet->isa == CS_ETM_ISA_T32)
-		sample->insn_len = cs_etm__t32_instr_size(etmq, trace_chan_id,
-							  sample->ip);
-	/* Otherwise, A64 and A32 instruction size are always 32-bit. */
-	else
-		sample->insn_len = 4;
+	sample->insn_len = cs_etm__instr_size(etmq, trace_chan_id,
+					      packet->isa, sample->ip);
 
 	cs_etm__mem_access(etmq, trace_chan_id, sample->ip,
 			   sample->insn_len, (void *)sample->insn);
-- 
2.17.1