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    Subject[PATCH 5.11 469/775] perf intel-pt: Fix IPC with CYC threshold
    Date
    From: Adrian Hunter <adrian.hunter@intel.com>

    [ Upstream commit 6af4b60033e0ce0332fcdf256c965ad41942821a ]

    The code assumed every CYC-eligible packet has a CYC packet, which is not
    the case when CYC thresholds are used. Fix by checking if a CYC packet is
    actually present in that case.

    Fixes: 5b1dc0fd1da06 ("perf intel-pt: Add support for samples to contain IPC ratio")
    Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
    Reviewed-by: Andi Kleen <ak@linux.intel.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Link: https://lore.kernel.org/r/20210205175350.23817-4-adrian.hunter@intel.com
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    .../util/intel-pt-decoder/intel-pt-decoder.c | 27 +++++++++++++++++++
    .../util/intel-pt-decoder/intel-pt-decoder.h | 1 +
    tools/perf/util/intel-pt.c | 13 +++++++++
    3 files changed, 41 insertions(+)

    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 ef29f6b25e60a..197eb58a39cb7 100644
    --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
    +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
    @@ -24,6 +24,13 @@
    #include "intel-pt-decoder.h"
    #include "intel-pt-log.h"

    +#define BITULL(x) (1ULL << (x))
    +
    +/* IA32_RTIT_CTL MSR bits */
    +#define INTEL_PT_CYC_ENABLE BITULL(1)
    +#define INTEL_PT_CYC_THRESHOLD (BITULL(22) | BITULL(21) | BITULL(20) | BITULL(19))
    +#define INTEL_PT_CYC_THRESHOLD_SHIFT 19
    +
    #define INTEL_PT_BLK_SIZE 1024

    #define BIT63 (((uint64_t)1 << 63))
    @@ -167,6 +174,8 @@ struct intel_pt_decoder {
    uint64_t sample_tot_cyc_cnt;
    uint64_t base_cyc_cnt;
    uint64_t cyc_cnt_timestamp;
    + uint64_t ctl;
    + uint64_t cyc_threshold;
    double tsc_to_cyc;
    bool continuous_period;
    bool overflow;
    @@ -204,6 +213,14 @@ static uint64_t intel_pt_lower_power_of_2(uint64_t x)
    return x << i;
    }

    +static uint64_t intel_pt_cyc_threshold(uint64_t ctl)
    +{
    + if (!(ctl & INTEL_PT_CYC_ENABLE))
    + return 0;
    +
    + return (ctl & INTEL_PT_CYC_THRESHOLD) >> INTEL_PT_CYC_THRESHOLD_SHIFT;
    +}
    +
    static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
    {
    if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
    @@ -245,12 +262,15 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)

    decoder->flags = params->flags;

    + decoder->ctl = params->ctl;
    decoder->period = params->period;
    decoder->period_type = params->period_type;

    decoder->max_non_turbo_ratio = params->max_non_turbo_ratio;
    decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;

    + decoder->cyc_threshold = intel_pt_cyc_threshold(decoder->ctl);
    +
    intel_pt_setup_period(decoder);

    decoder->mtc_shift = params->mtc_period;
    @@ -2017,6 +2037,7 @@ static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, in

    static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
    {
    + int last_packet_type = INTEL_PT_PAD;
    bool no_tip = false;
    int err;

    @@ -2025,6 +2046,12 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
    if (err)
    return err;
    next:
    + if (decoder->cyc_threshold) {
    + if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
    + decoder->sample_cyc = false;
    + last_packet_type = decoder->packet.type;
    + }
    +
    if (decoder->hop) {
    switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
    case HOP_IGNORE:
    diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h
    index b52937b03c8c8..48adaa78acfc2 100644
    --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h
    +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h
    @@ -244,6 +244,7 @@ struct intel_pt_params {
    void *data;
    bool return_compression;
    bool branch_enable;
    + uint64_t ctl;
    uint64_t period;
    enum intel_pt_period_type period_type;
    unsigned max_non_turbo_ratio;
    diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
    index d6d93ee030190..2fff6f760457f 100644
    --- a/tools/perf/util/intel-pt.c
    +++ b/tools/perf/util/intel-pt.c
    @@ -893,6 +893,18 @@ static bool intel_pt_sampling_mode(struct intel_pt *pt)
    return false;
    }

    +static u64 intel_pt_ctl(struct intel_pt *pt)
    +{
    + struct evsel *evsel;
    + u64 config;
    +
    + evlist__for_each_entry(pt->session->evlist, evsel) {
    + if (intel_pt_get_config(pt, &evsel->core.attr, &config))
    + return config;
    + }
    + return 0;
    +}
    +
    static u64 intel_pt_ns_to_ticks(const struct intel_pt *pt, u64 ns)
    {
    u64 quot, rem;
    @@ -1026,6 +1038,7 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
    params.data = ptq;
    params.return_compression = intel_pt_return_compression(pt);
    params.branch_enable = intel_pt_branch_enable(pt);
    + params.ctl = intel_pt_ctl(pt);
    params.max_non_turbo_ratio = pt->max_non_turbo_ratio;
    params.mtc_period = intel_pt_mtc_period(pt);
    params.tsc_ctc_ratio_n = pt->tsc_ctc_ratio_n;
    --
    2.27.0


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