perf intel-pt: Add decoder support for PEBS via PT

PEBS data is encoded in Block Item Packets (BIP). Populate a new structure
intel_pt_blk_items with the values and, upon a Block End Packet (BEP),
report them as a new Intel PT sample type INTEL_PT_BLK_ITEMS.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190610072803.10456-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 77 insertions, 1 deletions

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 2f7791d4034f..f8b71bf2bb4c 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -134,6 +134,9 @@ struct intel_pt_decoder {
 	struct intel_pt_stack stack;
 	enum intel_pt_pkt_state pkt_state;
 	enum intel_pt_pkt_ctx pkt_ctx;
+	enum intel_pt_pkt_ctx prev_pkt_ctx;
+	enum intel_pt_blk_type blk_type;
+	int blk_type_pos;
 	struct intel_pt_pkt packet;
 	struct intel_pt_pkt tnt;
 	int pkt_step;
@@ -167,6 +170,7 @@ struct intel_pt_decoder {
 	bool set_fup_mwait;
 	bool set_fup_pwre;
 	bool set_fup_exstop;
+	bool set_fup_bep;
 	bool sample_cyc;
 	unsigned int fup_tx_flags;
 	unsigned int tx_flags;
@@ -560,6 +564,7 @@ static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
 	memcpy(buf + len, decoder->buf, n);
 	len += n;
 
+	decoder->prev_pkt_ctx = decoder->pkt_ctx;
 	ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx);
 	if (ret < (int)old_len) {
 		decoder->next_buf = decoder->buf;
@@ -885,6 +890,7 @@ static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
 				return ret;
 		}
 
+		decoder->prev_pkt_ctx = decoder->pkt_ctx;
 		ret = intel_pt_get_packet(decoder->buf, decoder->len,
 					  &decoder->packet, &decoder->pkt_ctx);
 		if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 &&
@@ -1124,6 +1130,14 @@ static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
 		decoder->state.to_ip = 0;
 		ret = true;
 	}
+	if (decoder->set_fup_bep) {
+		decoder->set_fup_bep = false;
+		decoder->state.type |= INTEL_PT_BLK_ITEMS;
+		decoder->state.type &= ~INTEL_PT_BRANCH;
+		decoder->state.from_ip = decoder->ip;
+		decoder->state.to_ip = 0;
+		ret = true;
+	}
 	return ret;
 }
 
@@ -1609,6 +1623,46 @@ static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
 	intel_pt_log_to("Setting timestamp", decoder->timestamp);
 }
 
+static void intel_pt_bbp(struct intel_pt_decoder *decoder)
+{
+	if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
+		memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
+		decoder->state.items.is_32_bit = false;
+	}
+	decoder->blk_type = decoder->packet.payload;
+	decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
+	if (decoder->blk_type == INTEL_PT_GP_REGS)
+		decoder->state.items.is_32_bit = decoder->packet.count;
+	if (decoder->blk_type_pos < 0) {
+		intel_pt_log("WARNING: Unknown block type %u\n",
+			     decoder->blk_type);
+	} else if (decoder->state.items.mask[decoder->blk_type_pos]) {
+		intel_pt_log("WARNING: Duplicate block type %u\n",
+			     decoder->blk_type);
+	}
+}
+
+static void intel_pt_bip(struct intel_pt_decoder *decoder)
+{
+	uint32_t id = decoder->packet.count;
+	uint32_t bit = 1 << id;
+	int pos = decoder->blk_type_pos;
+
+	if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
+		intel_pt_log("WARNING: Unknown block item %u type %d\n",
+			     id, decoder->blk_type);
+		return;
+	}
+
+	if (decoder->state.items.mask[pos] & bit) {
+		intel_pt_log("WARNING: Duplicate block item %u type %d\n",
+			     id, decoder->blk_type);
+	}
+
+	decoder->state.items.mask[pos] |= bit;
+	decoder->state.items.val[pos][id] = decoder->packet.payload;
+}
+
 /* Walk PSB+ packets when already in sync. */
 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
 {
@@ -2063,10 +2117,31 @@ next:
 			return 0;
 
 		case INTEL_PT_BBP:
+			intel_pt_bbp(decoder);
+			break;
+
 		case INTEL_PT_BIP:
+			intel_pt_bip(decoder);
+			break;
+
 		case INTEL_PT_BEP:
+			decoder->state.type = INTEL_PT_BLK_ITEMS;
+			decoder->state.from_ip = decoder->ip;
+			decoder->state.to_ip = 0;
+			return 0;
+
 		case INTEL_PT_BEP_IP:
-			break;
+			err = intel_pt_get_next_packet(decoder);
+			if (err)
+				return err;
+			if (decoder->packet.type == INTEL_PT_FUP) {
+				decoder->set_fup_bep = true;
+				no_tip = true;
+			} else {
+				intel_pt_log_at("ERROR: Missing FUP after BEP",
+						decoder->pos);
+			}
+			goto next;
 
 		default:
 			return intel_pt_bug(decoder);
@@ -2335,6 +2410,7 @@ static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
 	decoder->set_fup_mwait = false;
 	decoder->set_fup_pwre = false;
 	decoder->set_fup_exstop = false;
+	decoder->set_fup_bep = false;
 
 	if (!decoder->branch_enable) {
 		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;