X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Ftools%2Fperf%2Futil%2Fintel-pt-decoder%2Fintel-pt-decoder.c;fp=kernel%2Ftools%2Fperf%2Futil%2Fintel-pt-decoder%2Fintel-pt-decoder.c;h=71df7acf86435bd000567b9a00acec9562b7e417;hb=52f993b8e89487ec9ee15a7fb4979e0f09a45b27;hp=9409d014b46c713de02df828cf9ad7ff726881e8;hpb=c189ccac5702322ed843fe17057035b7222a59b6;p=kvmfornfv.git

diff --git a/kernel/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/kernel/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 9409d014b..71df7acf8 100644
--- a/kernel/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/kernel/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -89,6 +89,7 @@ struct intel_pt_decoder {
 	bool pge;
 	bool have_tma;
 	bool have_cyc;
+	bool fixup_last_mtc;
 	uint64_t pos;
 	uint64_t last_ip;
 	uint64_t ip;
@@ -584,10 +585,31 @@ struct intel_pt_calc_cyc_to_tsc_info {
 	uint64_t        tsc_timestamp;
 	uint64_t        timestamp;
 	bool            have_tma;
+	bool            fixup_last_mtc;
 	bool            from_mtc;
 	double          cbr_cyc_to_tsc;
 };
 
+/*
+ * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
+ * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
+ * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
+ * packet by copying the missing bits from the current MTC assuming the least
+ * difference between the two, and that the current MTC comes after last_mtc.
+ */
+static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
+				    uint32_t *last_mtc)
+{
+	uint32_t first_missing_bit = 1U << (16 - mtc_shift);
+	uint32_t mask = ~(first_missing_bit - 1);
+
+	*last_mtc |= mtc & mask;
+	if (*last_mtc >= mtc) {
+		*last_mtc -= first_missing_bit;
+		*last_mtc &= 0xff;
+	}
+}
+
 static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
 {
 	struct intel_pt_decoder *decoder = pkt_info->decoder;
@@ -617,6 +639,11 @@ static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
 			return 0;
 
 		mtc = pkt_info->packet.payload;
+		if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
+			data->fixup_last_mtc = false;
+			intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
+						&data->last_mtc);
+		}
 		if (mtc > data->last_mtc)
 			mtc_delta = mtc - data->last_mtc;
 		else
@@ -685,6 +712,7 @@ static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
 
 		data->ctc_delta = 0;
 		data->have_tma = true;
+		data->fixup_last_mtc = true;
 
 		return 0;
 
@@ -751,6 +779,7 @@ static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
 		.tsc_timestamp  = decoder->tsc_timestamp,
 		.timestamp      = decoder->timestamp,
 		.have_tma       = decoder->have_tma,
+		.fixup_last_mtc = decoder->fixup_last_mtc,
 		.from_mtc       = from_mtc,
 		.cbr_cyc_to_tsc = 0,
 	};
@@ -1241,6 +1270,7 @@ static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
 	}
 	decoder->ctc_delta = 0;
 	decoder->have_tma = true;
+	decoder->fixup_last_mtc = true;
 	intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
 		     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
 }
@@ -1255,6 +1285,12 @@ static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
 
 	mtc = decoder->packet.payload;
 
+	if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
+		decoder->fixup_last_mtc = false;
+		intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
+					&decoder->last_mtc);
+	}
+
 	if (mtc > decoder->last_mtc)
 		mtc_delta = mtc - decoder->last_mtc;
 	else
@@ -1323,6 +1359,8 @@ static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
 			     timestamp, decoder->timestamp);
 	else
 		decoder->timestamp = timestamp;
+
+	decoder->timestamp_insn_cnt = 0;
 }
 
 /* Walk PSB+ packets when already in sync. */