diff options
Diffstat (limited to 'tools/perf/util/intel-pt-decoder/intel-pt-decoder.c')
| -rw-r--r-- | tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 62 |
1 files changed, 33 insertions, 29 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 6e03db142091..9d189e90fbdc 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -1,16 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * intel_pt_decoder.c: Intel Processor Trace support * Copyright (c) 2013-2014, Intel Corporation. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * */ #ifndef _GNU_SOURCE @@ -58,6 +49,7 @@ enum intel_pt_pkt_state { INTEL_PT_STATE_NO_IP, INTEL_PT_STATE_ERR_RESYNC, INTEL_PT_STATE_IN_SYNC, + INTEL_PT_STATE_TNT_CONT, INTEL_PT_STATE_TNT, INTEL_PT_STATE_TIP, INTEL_PT_STATE_TIP_PGD, @@ -72,8 +64,9 @@ static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state) case INTEL_PT_STATE_NO_IP: case INTEL_PT_STATE_ERR_RESYNC: case INTEL_PT_STATE_IN_SYNC: - case INTEL_PT_STATE_TNT: + case INTEL_PT_STATE_TNT_CONT: return true; + case INTEL_PT_STATE_TNT: case INTEL_PT_STATE_TIP: case INTEL_PT_STATE_TIP_PGD: case INTEL_PT_STATE_FUP: @@ -251,19 +244,15 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params) if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d)) decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n / decoder->tsc_ctc_ratio_d; - - /* - * Allow for timestamps appearing to backwards because a TSC - * packet has slipped past a MTC packet, so allow 2 MTC ticks - * or ... - */ - decoder->tsc_slip = multdiv(2 << decoder->mtc_shift, - decoder->tsc_ctc_ratio_n, - decoder->tsc_ctc_ratio_d); } - /* ... or 0x100 paranoia */ - if (decoder->tsc_slip < 0x100) - decoder->tsc_slip = 0x100; + + /* + * A TSC packet can slip past MTC packets so that the timestamp appears + * to go backwards. One estimate is that can be up to about 40 CPU + * cycles, which is certainly less than 0x1000 TSC ticks, but accept + * slippage an order of magnitude more to be on the safe side. + */ + decoder->tsc_slip = 0x10000; intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift); intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n); @@ -892,16 +881,20 @@ static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder) timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; if (decoder->continuous_period) { - if (masked_timestamp != decoder->last_masked_timestamp) + if (masked_timestamp > decoder->last_masked_timestamp) return 1; } else { timestamp += 1; masked_timestamp = timestamp & decoder->period_mask; - if (masked_timestamp != decoder->last_masked_timestamp) { + if (masked_timestamp > decoder->last_masked_timestamp) { decoder->last_masked_timestamp = masked_timestamp; decoder->continuous_period = true; } } + + if (masked_timestamp < decoder->last_masked_timestamp) + return decoder->period_ticks; + return decoder->period_ticks - (timestamp - masked_timestamp); } @@ -930,7 +923,10 @@ static void intel_pt_sample_insn(struct intel_pt_decoder *decoder) case INTEL_PT_PERIOD_TICKS: timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; - decoder->last_masked_timestamp = masked_timestamp; + if (masked_timestamp > decoder->last_masked_timestamp) + decoder->last_masked_timestamp = masked_timestamp; + else + decoder->last_masked_timestamp += decoder->period_ticks; break; case INTEL_PT_PERIOD_NONE: case INTEL_PT_PERIOD_MTC: @@ -1258,7 +1254,9 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) return -ENOENT; } decoder->tnt.count -= 1; - if (!decoder->tnt.count) + if (decoder->tnt.count) + decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; + else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->tnt.payload <<= 1; decoder->state.from_ip = decoder->ip; @@ -1289,7 +1287,9 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) { decoder->tnt.count -= 1; - if (!decoder->tnt.count) + if (decoder->tnt.count) + decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; + else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; if (decoder->tnt.payload & BIT63) { decoder->tnt.payload <<= 1; @@ -1309,8 +1309,11 @@ static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) return 0; } decoder->ip += intel_pt_insn.length; - if (!decoder->tnt.count) + if (!decoder->tnt.count) { + decoder->sample_timestamp = decoder->timestamp; + decoder->sample_insn_cnt = decoder->timestamp_insn_cnt; return -EAGAIN; + } decoder->tnt.payload <<= 1; continue; } @@ -2369,6 +2372,7 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder) err = intel_pt_walk_trace(decoder); break; case INTEL_PT_STATE_TNT: + case INTEL_PT_STATE_TNT_CONT: err = intel_pt_walk_tnt(decoder); if (err == -EAGAIN) err = intel_pt_walk_trace(decoder); |
