From: Mathieu Poirier mathieu.poirier@linaro.org

When operating in CPU-wide mode being notified of contextID changes is required so that the decoding mechanic is aware of the process context switch.

Signed-off-by: Mathieu Poirier mathieu.poirier@linaro.org Reviewed-by: Suzuki Poulouse suzuki.poulose@arm.com Tested-by: Leo Yan leo.yan@linaro.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Suzuki Poulouse suzuki.poulose@arm.com Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20190524173508.29044-2-mathieu.poirier@linaro.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com --- tools/perf/arch/arm/util/cs-etm.c | 126 +++++++++++++++++++++++++----- tools/perf/util/cs-etm.h | 12 +++ 2 files changed, 119 insertions(+), 19 deletions(-)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index 911426721170..3912f0bf04ed 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c @@ -35,8 +35,100 @@ struct cs_etm_recording { size_t snapshot_size; };

+static const char *metadata_etmv3_ro[CS_ETM_PRIV_MAX] = { + [CS_ETM_ETMCCER] = "mgmt/etmccer", + [CS_ETM_ETMIDR] = "mgmt/etmidr", +}; + +static const char *metadata_etmv4_ro[CS_ETMV4_PRIV_MAX] = { + [CS_ETMV4_TRCIDR0] = "trcidr/trcidr0", + [CS_ETMV4_TRCIDR1] = "trcidr/trcidr1", + [CS_ETMV4_TRCIDR2] = "trcidr/trcidr2", + [CS_ETMV4_TRCIDR8] = "trcidr/trcidr8", + [CS_ETMV4_TRCAUTHSTATUS] = "mgmt/trcauthstatus", +}; + static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu);

+static int cs_etm_set_context_id(struct auxtrace_record *itr, + struct perf_evsel *evsel, int cpu) +{ + struct cs_etm_recording *ptr; + struct perf_pmu *cs_etm_pmu; + char path[PATH_MAX]; + int err = -EINVAL; + u32 val; + + ptr = container_of(itr, struct cs_etm_recording, itr); + cs_etm_pmu = ptr->cs_etm_pmu; + + if (!cs_etm_is_etmv4(itr, cpu)) + goto out; + + /* Get a handle on TRCIRD2 */ + snprintf(path, PATH_MAX, "cpu%d/%s", + cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR2]); + err = perf_pmu__scan_file(cs_etm_pmu, path, "%x", &val); + + /* There was a problem reading the file, bailing out */ + if (err != 1) { + pr_err("%s: can't read file %s\n", + CORESIGHT_ETM_PMU_NAME, path); + goto out; + } + + /* + * TRCIDR2.CIDSIZE, bit [9-5], indicates whether contextID tracing + * is supported: + * 0b00000 Context ID tracing is not supported. + * 0b00100 Maximum of 32-bit Context ID size. + * All other values are reserved. + */ + val = BMVAL(val, 5, 9); + if (!val || val != 0x4) { + err = -EINVAL; + goto out; + } + + /* All good, let the kernel know */ + evsel->attr.config |= (1 << ETM_OPT_CTXTID); + err = 0; + +out: + + return err; +} + +static int cs_etm_set_option(struct auxtrace_record *itr, + struct perf_evsel *evsel, u32 option) +{ + int i, err = -EINVAL; + struct cpu_map *event_cpus = evsel->evlist->cpus; + struct cpu_map *online_cpus = cpu_map__new(NULL); + + /* Set option of each CPU we have */ + for (i = 0; i < cpu__max_cpu(); i++) { + if (!cpu_map__has(event_cpus, i) || + !cpu_map__has(online_cpus, i)) + continue; + + switch (option) { + case ETM_OPT_CTXTID: + err = cs_etm_set_context_id(itr, evsel, i); + if (err) + goto out; + break; + default: + goto out; + } + } + + err = 0; +out: + cpu_map__put(online_cpus); + return err; +} + static int cs_etm_parse_snapshot_options(struct auxtrace_record *itr, struct record_opts *opts, const char *str) @@ -105,8 +197,9 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, container_of(itr, struct cs_etm_recording, itr); struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu; struct perf_evsel *evsel, *cs_etm_evsel = NULL; - const struct cpu_map *cpus = evlist->cpus; + struct cpu_map *cpus = evlist->cpus; bool privileged = (geteuid() == 0 || perf_event_paranoid() < 0); + int err = 0;

ptr->evlist = evlist; ptr->snapshot_mode = opts->auxtrace_snapshot_mode; @@ -241,19 +334,24 @@ static int cs_etm_recording_options(struct auxtrace_record *itr,

/* * In the case of per-cpu mmaps, we need the CPU on the - * AUX event. + * AUX event. We also need the contextID in order to be notified + * when a context switch happened. */ - if (!cpu_map__empty(cpus)) + if (!cpu_map__empty(cpus)) { perf_evsel__set_sample_bit(cs_etm_evsel, CPU);

+ err = cs_etm_set_option(itr, cs_etm_evsel, ETM_OPT_CTXTID); + if (err) + goto out; + } + /* Add dummy event to keep tracking */ if (opts->full_auxtrace) { struct perf_evsel *tracking_evsel; - int err;

err = parse_events(evlist, "dummy:u", NULL); if (err) - return err; + goto out;

tracking_evsel = perf_evlist__last(evlist); perf_evlist__set_tracking_event(evlist, tracking_evsel); @@ -266,7 +364,8 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, perf_evsel__set_sample_bit(tracking_evsel, TIME); }

- return 0; +out: + return err; }

static u64 cs_etm_get_config(struct auxtrace_record *itr) @@ -314,6 +413,8 @@ static u64 cs_etmv4_get_config(struct auxtrace_record *itr) config_opts = cs_etm_get_config(itr); if (config_opts & BIT(ETM_OPT_CYCACC)) config |= BIT(ETM4_CFG_BIT_CYCACC); + if (config_opts & BIT(ETM_OPT_CTXTID)) + config |= BIT(ETM4_CFG_BIT_CTXTID); if (config_opts & BIT(ETM_OPT_TS)) config |= BIT(ETM4_CFG_BIT_TS); if (config_opts & BIT(ETM_OPT_RETSTK)) @@ -363,19 +464,6 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused, (etmv3 * CS_ETMV3_PRIV_SIZE)); }

-static const char *metadata_etmv3_ro[CS_ETM_PRIV_MAX] = { - [CS_ETM_ETMCCER] = "mgmt/etmccer", - [CS_ETM_ETMIDR] = "mgmt/etmidr", -}; - -static const char *metadata_etmv4_ro[CS_ETMV4_PRIV_MAX] = { - [CS_ETMV4_TRCIDR0] = "trcidr/trcidr0", - [CS_ETMV4_TRCIDR1] = "trcidr/trcidr1", - [CS_ETMV4_TRCIDR2] = "trcidr/trcidr2", - [CS_ETMV4_TRCIDR8] = "trcidr/trcidr8", - [CS_ETMV4_TRCAUTHSTATUS] = "mgmt/trcauthstatus", -}; - static bool cs_etm_is_etmv4(struct auxtrace_record *itr, int cpu) { bool ret = false; diff --git a/tools/perf/util/cs-etm.h b/tools/perf/util/cs-etm.h index 0e97c196147a..826c9eedaf5c 100644 --- a/tools/perf/util/cs-etm.h +++ b/tools/perf/util/cs-etm.h @@ -103,6 +103,18 @@ struct intlist *traceid_list; #define KiB(x) ((x) * 1024) #define MiB(x) ((x) * 1024 * 1024)

+/* + * Create a contiguous bitmask starting at bit position @l and ending at + * position @h. For example + * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. + * + * Carbon copy of implementation found in $KERNEL/include/linux/bitops.h + */ +#define GENMASK(h, l) \ + (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) + +#define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb) + #define CS_ETM_HEADER_SIZE (CS_HEADER_VERSION_0_MAX * sizeof(u64))

#define __perf_cs_etmv3_magic 0x3030303030303030ULL