From: Mike Leach Date: Fri, 31 Mar 2023 05:56:44 +0000 (+0100) Subject: perf cs-etm: Update record event to use new Trace ID protocol X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e5fa5b4110fe7d0ab08252943fc47072a7ff6c9d;p=linux.git perf cs-etm: Update record event to use new Trace ID protocol Trace IDs are now dynamically allocated. Previously used the static association algorithm that is no longer used. The 'cpu * 2 + seed' was outdated and broken for systems with high core counts (>46). as it did not scale and was broken for larger core counts. Trace ID will now be sent in PERF_RECORD_AUX_OUTPUT_HW_ID record. Legacy ID algorithm renamed and retained for limited backward compatibility use. Reviewed-by: James Clark Signed-off-by: Mike Leach Acked-by: Suzuki Poulouse Cc: Alexander Shishkin Cc: Darren Hart Cc: Ganapatrao Kulkarni Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Will Deacon Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230331055645.26918-2-mike.leach@linaro.org Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h index db9c7c0abb6a0..1760f9a574b08 100644 --- a/tools/include/linux/coresight-pmu.h +++ b/tools/include/linux/coresight-pmu.h @@ -10,11 +10,27 @@ #include #define CORESIGHT_ETM_PMU_NAME "cs_etm" -#define CORESIGHT_ETM_PMU_SEED 0x10 + +/* + * The legacy Trace ID system based on fixed calculation from the cpu + * number. This has been replaced by drivers using a dynamic allocation + * system - but need to retain the legacy algorithm for backward comparibility + * in certain situations:- + * a) new perf running on older systems that generate the legacy mapping + * b) older tools that may not update at the same time as the kernel. + */ +#define CORESIGHT_LEGACY_CPU_TRACE_ID(cpu) (0x10 + (cpu * 2)) /* CoreSight trace ID is currently the bottom 7 bits of the value */ #define CORESIGHT_TRACE_ID_VAL_MASK GENMASK(6, 0) +/* + * perf record will set the legacy meta data values as unused initially. + * This allows perf report to manage the decoders created when dynamic + * allocation in operation. + */ +#define CORESIGHT_TRACE_ID_UNUSED_FLAG BIT(31) + /* * Below are the definition of bit offsets for perf option, and works as * arbitrary values for all ETM versions. @@ -39,15 +55,4 @@ #define ETM4_CFG_BIT_RETSTK 12 #define ETM4_CFG_BIT_VMID_OPT 15 -static inline int coresight_get_trace_id(int cpu) -{ - /* - * A trace ID of value 0 is invalid, so let's start at some - * random value that fits in 7 bits and go from there. Since - * the common convention is to have data trace IDs be I(N) + 1, - * set instruction trace IDs as a function of the CPU number. - */ - return (CORESIGHT_ETM_PMU_SEED + (cpu * 2)); -} - #endif diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index 86b61ad74f90a..e02a9bfc3d421 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c @@ -437,13 +437,16 @@ static int cs_etm_recording_options(struct auxtrace_record *itr, evlist__to_front(evlist, cs_etm_evsel); /* - * In the case of per-cpu mmaps, we need the CPU on the - * AUX event. We also need the contextID in order to be notified + * get the CPU on the sample - need it to associate trace ID in the + * AUX_OUTPUT_HW_ID event, and the AUX event for per-cpu mmaps. + */ + evsel__set_sample_bit(cs_etm_evsel, CPU); + + /* + * Also the case of per-cpu mmaps, need the contextID in order to be notified * when a context switch happened. */ if (!perf_cpu_map__empty(cpus)) { - evsel__set_sample_bit(cs_etm_evsel, CPU); - err = cs_etm_set_option(itr, cs_etm_evsel, BIT(ETM_OPT_CTXTID) | BIT(ETM_OPT_TS)); if (err) @@ -679,8 +682,10 @@ static void cs_etm_save_etmv4_header(__u64 data[], struct auxtrace_record *itr, /* Get trace configuration register */ data[CS_ETMV4_TRCCONFIGR] = cs_etmv4_get_config(itr); - /* Get traceID from the framework */ - data[CS_ETMV4_TRCTRACEIDR] = coresight_get_trace_id(cpu); + /* traceID set to legacy version, in case new perf running on older system */ + data[CS_ETMV4_TRCTRACEIDR] = + CORESIGHT_LEGACY_CPU_TRACE_ID(cpu) | CORESIGHT_TRACE_ID_UNUSED_FLAG; + /* Get read-only information from sysFS */ data[CS_ETMV4_TRCIDR0] = cs_etm_get_ro(cs_etm_pmu, cpu, metadata_etmv4_ro[CS_ETMV4_TRCIDR0]); @@ -711,8 +716,10 @@ static void cs_etm_save_ete_header(__u64 data[], struct auxtrace_record *itr, in /* Get trace configuration register */ data[CS_ETE_TRCCONFIGR] = cs_etmv4_get_config(itr); - /* Get traceID from the framework */ - data[CS_ETE_TRCTRACEIDR] = coresight_get_trace_id(cpu); + /* traceID set to legacy version, in case new perf running on older system */ + data[CS_ETE_TRCTRACEIDR] = + CORESIGHT_LEGACY_CPU_TRACE_ID(cpu) | CORESIGHT_TRACE_ID_UNUSED_FLAG; + /* Get read-only information from sysFS */ data[CS_ETE_TRCIDR0] = cs_etm_get_ro(cs_etm_pmu, cpu, metadata_ete_ro[CS_ETE_TRCIDR0]); @@ -768,9 +775,9 @@ static void cs_etm_get_metadata(int cpu, u32 *offset, magic = __perf_cs_etmv3_magic; /* Get configuration register */ info->priv[*offset + CS_ETM_ETMCR] = cs_etm_get_config(itr); - /* Get traceID from the framework */ + /* traceID set to legacy value in case new perf running on old system */ info->priv[*offset + CS_ETM_ETMTRACEIDR] = - coresight_get_trace_id(cpu); + CORESIGHT_LEGACY_CPU_TRACE_ID(cpu) | CORESIGHT_TRACE_ID_UNUSED_FLAG; /* Get read-only information from sysFS */ info->priv[*offset + CS_ETM_ETMCCER] = cs_etm_get_ro(cs_etm_pmu, cpu,