diff options
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etm4x-core.c | 63 | ||||
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etm4x.h | 7 | ||||
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-self-hosted-trace.h | 7 |
3 files changed, 59 insertions, 18 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 537c0d7ee1ed..d9a85ca25b60 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -239,6 +239,45 @@ struct etm4_enable_arg { int rc; }; +/* + * etm4x_prohibit_trace - Prohibit the CPU from tracing at all ELs. + * When the CPU supports FEAT_TRF, we could move the ETM to a trace + * prohibited state by filtering the Exception levels via TRFCR_EL1. + */ +static void etm4x_prohibit_trace(struct etmv4_drvdata *drvdata) +{ + /* If the CPU doesn't support FEAT_TRF, nothing to do */ + if (!drvdata->trfcr) + return; + cpu_prohibit_trace(); +} + +/* + * etm4x_allow_trace - Allow CPU tracing in the respective ELs, + * as configured by the drvdata->config.mode for the current + * session. Even though we have TRCVICTLR bits to filter the + * trace in the ELs, it doesn't prevent the ETM from generating + * a packet (e.g, TraceInfo) that might contain the addresses from + * the excluded levels. Thus we use the additional controls provided + * via the Trace Filtering controls (FEAT_TRF) to make sure no trace + * is generated for the excluded ELs. + */ +static void etm4x_allow_trace(struct etmv4_drvdata *drvdata) +{ + u64 trfcr = drvdata->trfcr; + + /* If the CPU doesn't support FEAT_TRF, nothing to do */ + if (!trfcr) + return; + + if (drvdata->config.mode & ETM_MODE_EXCL_KERN) + trfcr &= ~TRFCR_ELx_ExTRE; + if (drvdata->config.mode & ETM_MODE_EXCL_USER) + trfcr &= ~TRFCR_ELx_E0TRE; + + write_trfcr(trfcr); +} + #ifdef CONFIG_ETM4X_IMPDEF_FEATURE #define HISI_HIP08_AMBA_ID 0x000b6d01 @@ -443,6 +482,7 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata) if (etm4x_is_ete(drvdata)) etm4x_relaxed_write32(csa, TRCRSR_TA, TRCRSR); + etm4x_allow_trace(drvdata); /* Enable the trace unit */ etm4x_relaxed_write32(csa, 1, TRCPRGCTLR); @@ -738,7 +778,6 @@ static int etm4_enable(struct coresight_device *csdev, static void etm4_disable_hw(void *info) { u32 control; - u64 trfcr; struct etmv4_drvdata *drvdata = info; struct etmv4_config *config = &drvdata->config; struct coresight_device *csdev = drvdata->csdev; @@ -765,12 +804,7 @@ static void etm4_disable_hw(void *info) * If the CPU supports v8.4 Trace filter Control, * set the ETM to trace prohibited region. */ - if (drvdata->trfc) { - trfcr = read_sysreg_s(SYS_TRFCR_EL1); - write_sysreg_s(trfcr & ~(TRFCR_ELx_ExTRE | TRFCR_ELx_E0TRE), - SYS_TRFCR_EL1); - isb(); - } + etm4x_prohibit_trace(drvdata); /* * Make sure everything completes before disabling, as recommended * by section 7.3.77 ("TRCVICTLR, ViewInst Main Control Register, @@ -786,9 +820,6 @@ static void etm4_disable_hw(void *info) if (coresight_timeout(csa, TRCSTATR, TRCSTATR_PMSTABLE_BIT, 1)) dev_err(etm_dev, "timeout while waiting for PM stable Trace Status\n"); - if (drvdata->trfc) - write_sysreg_s(trfcr, SYS_TRFCR_EL1); - /* read the status of the single shot comparators */ for (i = 0; i < drvdata->nr_ss_cmp; i++) { config->ss_status[i] = @@ -990,15 +1021,15 @@ static bool etm4_init_csdev_access(struct etmv4_drvdata *drvdata, return false; } -static void cpu_enable_tracing(struct etmv4_drvdata *drvdata) +static void cpu_detect_trace_filtering(struct etmv4_drvdata *drvdata) { u64 dfr0 = read_sysreg(id_aa64dfr0_el1); u64 trfcr; + drvdata->trfcr = 0; if (!cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRACE_FILT_SHIFT)) return; - drvdata->trfc = true; /* * If the CPU supports v8.4 SelfHosted Tracing, enable * tracing at the kernel EL and EL0, forcing to use the @@ -1012,7 +1043,7 @@ static void cpu_enable_tracing(struct etmv4_drvdata *drvdata) if (is_kernel_in_hyp_mode()) trfcr |= TRFCR_EL2_CX; - write_trfcr(trfcr); + drvdata->trfcr = trfcr; } static void etm4_init_arch_data(void *info) @@ -1203,7 +1234,7 @@ static void etm4_init_arch_data(void *info) /* NUMCNTR, bits[30:28] number of counters available for tracing */ drvdata->nr_cntr = BMVAL(etmidr5, 28, 30); etm4_cs_lock(drvdata, csa); - cpu_enable_tracing(drvdata); + cpu_detect_trace_filtering(drvdata); } static inline u32 etm4_get_victlr_access_type(struct etmv4_config *config) @@ -1699,7 +1730,7 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata) int ret = 0; /* Save the TRFCR irrespective of whether the ETM is ON */ - if (drvdata->trfc) + if (drvdata->trfcr) drvdata->save_trfcr = read_trfcr(); /* * Save and restore the ETM Trace registers only if @@ -1808,7 +1839,7 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata) static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) { - if (drvdata->trfc) + if (drvdata->trfcr) write_trfcr(drvdata->save_trfcr); if (drvdata->state_needs_restore) __etm4_cpu_restore(drvdata); diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index 82cba16b73a6..3c4d69b096ca 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -919,7 +919,10 @@ struct etmv4_save_state { * @nooverflow: Indicate if overflow prevention is supported. * @atbtrig: If the implementation can support ATB triggers * @lpoverride: If the implementation can support low-power state over. - * @trfc: If the implementation supports Arm v8.4 trace filter controls. + * @trfcr: If the CPU supports FEAT_TRF, value of the TRFCR_ELx that + * allows tracing at all ELs. We don't want to compute this + * at runtime, due to the additional setting of TRFCR_CX when + * in EL2. Otherwise, 0. * @config: structure holding configuration parameters. * @save_trfcr: Saved TRFCR_EL1 register during a CPU PM event. * @save_state: State to be preserved across power loss @@ -972,7 +975,7 @@ struct etmv4_drvdata { bool nooverflow; bool atbtrig; bool lpoverride; - bool trfc; + u64 trfcr; struct etmv4_config config; u64 save_trfcr; struct etmv4_save_state *save_state; diff --git a/drivers/hwtracing/coresight/coresight-self-hosted-trace.h b/drivers/hwtracing/coresight/coresight-self-hosted-trace.h index 303d71911870..23f05df3f173 100644 --- a/drivers/hwtracing/coresight/coresight-self-hosted-trace.h +++ b/drivers/hwtracing/coresight/coresight-self-hosted-trace.h @@ -21,4 +21,11 @@ static inline void write_trfcr(u64 val) isb(); } +static inline void cpu_prohibit_trace(void) +{ + u64 trfcr = read_trfcr(); + + /* Prohibit tracing at EL0 & the kernel EL */ + write_trfcr(trfcr & ~(TRFCR_ELx_ExTRE | TRFCR_ELx_E0TRE)); +} #endif /* __CORESIGHT_SELF_HOSTED_TRACE_H */ |