// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2014, The Linux Foundation. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "coresight-etm4x.h" #include "coresight-etm-perf.h" #include "coresight-etm4x-cfg.h" #include "coresight-self-hosted-trace.h" #include "coresight-syscfg.h" static int boot_enable; module_param(boot_enable, int, 0444); MODULE_PARM_DESC(boot_enable, "Enable tracing on boot"); #define PARAM_PM_SAVE_FIRMWARE 0 /* save self-hosted state as per firmware */ #define PARAM_PM_SAVE_NEVER 1 /* never save any state */ #define PARAM_PM_SAVE_SELF_HOSTED 2 /* save self-hosted state only */ static int pm_save_enable = PARAM_PM_SAVE_FIRMWARE; module_param(pm_save_enable, int, 0444); MODULE_PARM_DESC(pm_save_enable, "Save/restore state on power down: 1 = never, 2 = self-hosted"); static struct etmv4_drvdata *etmdrvdata[NR_CPUS]; static void etm4_set_default_config(struct etmv4_config *config); static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, struct perf_event *event); static u64 etm4_get_access_type(struct etmv4_config *config); static enum cpuhp_state hp_online; struct etm4_init_arg { unsigned int pid; struct etmv4_drvdata *drvdata; struct csdev_access *csa; }; /* * Check if TRCSSPCICRn(i) is implemented for a given instance. * * TRCSSPCICRn is implemented only if : * TRCSSPCICR is present only if all of the following are true: * TRCIDR4.NUMSSCC > n. * TRCIDR4.NUMPC > 0b0000 . * TRCSSCSR.PC == 0b1 */ static inline bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n) { return (n < drvdata->nr_ss_cmp) && drvdata->nr_pe && (drvdata->config.ss_status[n] & TRCSSCSRn_PC); } u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit) { u64 res = 0; switch (offset) { ETM4x_READ_SYSREG_CASES(res) default : pr_warn_ratelimited("etm4x: trying to read unsupported register @%x\n", offset); } if (!_relaxed) __io_ar(res); /* Imitate the !relaxed I/O helpers */ return res; } void etm4x_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit) { if (!_relaxed) __io_bw(); /* Imitate the !relaxed I/O helpers */ if (!_64bit) val &= GENMASK(31, 0); switch (offset) { ETM4x_WRITE_SYSREG_CASES(val) default : pr_warn_ratelimited("etm4x: trying to write to unsupported register @%x\n", offset); } } static u64 ete_sysreg_read(u32 offset, bool _relaxed, bool _64bit) { u64 res = 0; switch (offset) { ETE_READ_CASES(res) default : pr_warn_ratelimited("ete: trying to read unsupported register @%x\n", offset); } if (!_relaxed) __io_ar(res); /* Imitate the !relaxed I/O helpers */ return res; } static void ete_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit) { if (!_relaxed) __io_bw(); /* Imitate the !relaxed I/O helpers */ if (!_64bit) val &= GENMASK(31, 0); switch (offset) { ETE_WRITE_CASES(val) default : pr_warn_ratelimited("ete: trying to write to unsupported register @%x\n", offset); } } static void etm_detect_os_lock(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { u32 oslsr = etm4x_relaxed_read32(csa, TRCOSLSR); drvdata->os_lock_model = ETM_OSLSR_OSLM(oslsr); } static void etm_write_os_lock(struct etmv4_drvdata *drvdata, struct csdev_access *csa, u32 val) { val = !!val; switch (drvdata->os_lock_model) { case ETM_OSLOCK_PRESENT: etm4x_relaxed_write32(csa, val, TRCOSLAR); break; case ETM_OSLOCK_PE: write_sysreg_s(val, SYS_OSLAR_EL1); break; default: pr_warn_once("CPU%d: Unsupported Trace OSLock model: %x\n", smp_processor_id(), drvdata->os_lock_model); fallthrough; case ETM_OSLOCK_NI: return; } isb(); } static inline void etm4_os_unlock_csa(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { WARN_ON(drvdata->cpu != smp_processor_id()); /* Writing 0 to OS Lock unlocks the trace unit registers */ etm_write_os_lock(drvdata, csa, 0x0); drvdata->os_unlock = true; } static void etm4_os_unlock(struct etmv4_drvdata *drvdata) { if (!WARN_ON(!drvdata->csdev)) etm4_os_unlock_csa(drvdata, &drvdata->csdev->access); } static void etm4_os_lock(struct etmv4_drvdata *drvdata) { if (WARN_ON(!drvdata->csdev)) return; /* Writing 0x1 to OS Lock locks the trace registers */ etm_write_os_lock(drvdata, &drvdata->csdev->access, 0x1); drvdata->os_unlock = false; } static void etm4_cs_lock(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { /* Software Lock is only accessible via memory mapped interface */ if (csa->io_mem) CS_LOCK(csa->base); } static void etm4_cs_unlock(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { if (csa->io_mem) CS_UNLOCK(csa->base); } static int etm4_cpu_id(struct coresight_device *csdev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); return drvdata->cpu; } static int etm4_trace_id(struct coresight_device *csdev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); return drvdata->trcid; } struct etm4_enable_arg { struct etmv4_drvdata *drvdata; 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 #define ETM4_AMBA_MASK 0xfffff #define HISI_HIP08_CORE_COMMIT_MASK 0x3000 #define HISI_HIP08_CORE_COMMIT_SHIFT 12 #define HISI_HIP08_CORE_COMMIT_FULL 0b00 #define HISI_HIP08_CORE_COMMIT_LVL_1 0b01 #define HISI_HIP08_CORE_COMMIT_REG sys_reg(3, 1, 15, 2, 5) struct etm4_arch_features { void (*arch_callback)(bool enable); }; static bool etm4_hisi_match_pid(unsigned int id) { return (id & ETM4_AMBA_MASK) == HISI_HIP08_AMBA_ID; } static void etm4_hisi_config_core_commit(bool enable) { u8 commit = enable ? HISI_HIP08_CORE_COMMIT_LVL_1 : HISI_HIP08_CORE_COMMIT_FULL; u64 val; /* * bit 12 and 13 of HISI_HIP08_CORE_COMMIT_REG are used together * to set core-commit, 2'b00 means cpu is at full speed, 2'b01, * 2'b10, 2'b11 mean reduce pipeline speed, and 2'b01 means level-1 * speed(minimun value). So bit 12 and 13 should be cleared together. */ val = read_sysreg_s(HISI_HIP08_CORE_COMMIT_REG); val &= ~HISI_HIP08_CORE_COMMIT_MASK; val |= commit << HISI_HIP08_CORE_COMMIT_SHIFT; write_sysreg_s(val, HISI_HIP08_CORE_COMMIT_REG); } static struct etm4_arch_features etm4_features[] = { [ETM4_IMPDEF_HISI_CORE_COMMIT] = { .arch_callback = etm4_hisi_config_core_commit, }, {}, }; static void etm4_enable_arch_specific(struct etmv4_drvdata *drvdata) { struct etm4_arch_features *ftr; int bit; for_each_set_bit(bit, drvdata->arch_features, ETM4_IMPDEF_FEATURE_MAX) { ftr = &etm4_features[bit]; if (ftr->arch_callback) ftr->arch_callback(true); } } static void etm4_disable_arch_specific(struct etmv4_drvdata *drvdata) { struct etm4_arch_features *ftr; int bit; for_each_set_bit(bit, drvdata->arch_features, ETM4_IMPDEF_FEATURE_MAX) { ftr = &etm4_features[bit]; if (ftr->arch_callback) ftr->arch_callback(false); } } static void etm4_check_arch_features(struct etmv4_drvdata *drvdata, unsigned int id) { if (etm4_hisi_match_pid(id)) set_bit(ETM4_IMPDEF_HISI_CORE_COMMIT, drvdata->arch_features); } #else static void etm4_enable_arch_specific(struct etmv4_drvdata *drvdata) { } static void etm4_disable_arch_specific(struct etmv4_drvdata *drvdata) { } static void etm4_check_arch_features(struct etmv4_drvdata *drvdata, unsigned int id) { } #endif /* CONFIG_ETM4X_IMPDEF_FEATURE */ static int etm4_enable_hw(struct etmv4_drvdata *drvdata) { int i, rc; struct etmv4_config *config = &drvdata->config; struct coresight_device *csdev = drvdata->csdev; struct device *etm_dev = &csdev->dev; struct csdev_access *csa = &csdev->access; etm4_cs_unlock(drvdata, csa); etm4_enable_arch_specific(drvdata); etm4_os_unlock(drvdata); rc = coresight_claim_device_unlocked(csdev); if (rc) goto done; /* Disable the trace unit before programming trace registers */ etm4x_relaxed_write32(csa, 0, TRCPRGCTLR); /* * If we use system instructions, we need to synchronize the * write to the TRCPRGCTLR, before accessing the TRCSTATR. * See ARM IHI0064F, section * "4.3.7 Synchronization of register updates" */ if (!csa->io_mem) isb(); /* wait for TRCSTATR.IDLE to go up */ if (coresight_timeout(csa, TRCSTATR, TRCSTATR_IDLE_BIT, 1)) dev_err(etm_dev, "timeout while waiting for Idle Trace Status\n"); if (drvdata->nr_pe) etm4x_relaxed_write32(csa, config->pe_sel, TRCPROCSELR); etm4x_relaxed_write32(csa, config->cfg, TRCCONFIGR); /* nothing specific implemented */ etm4x_relaxed_write32(csa, 0x0, TRCAUXCTLR); etm4x_relaxed_write32(csa, config->eventctrl0, TRCEVENTCTL0R); etm4x_relaxed_write32(csa, config->eventctrl1, TRCEVENTCTL1R); if (drvdata->stallctl) etm4x_relaxed_write32(csa, config->stall_ctrl, TRCSTALLCTLR); etm4x_relaxed_write32(csa, config->ts_ctrl, TRCTSCTLR); etm4x_relaxed_write32(csa, config->syncfreq, TRCSYNCPR); etm4x_relaxed_write32(csa, config->ccctlr, TRCCCCTLR); etm4x_relaxed_write32(csa, config->bb_ctrl, TRCBBCTLR); etm4x_relaxed_write32(csa, drvdata->trcid, TRCTRACEIDR); etm4x_relaxed_write32(csa, config->vinst_ctrl, TRCVICTLR); etm4x_relaxed_write32(csa, config->viiectlr, TRCVIIECTLR); etm4x_relaxed_write32(csa, config->vissctlr, TRCVISSCTLR); if (drvdata->nr_pe_cmp) etm4x_relaxed_write32(csa, config->vipcssctlr, TRCVIPCSSCTLR); for (i = 0; i < drvdata->nrseqstate - 1; i++) etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i)); etm4x_relaxed_write32(csa, config->seq_rst, TRCSEQRSTEVR); etm4x_relaxed_write32(csa, config->seq_state, TRCSEQSTR); etm4x_relaxed_write32(csa, config->ext_inp, TRCEXTINSELR); for (i = 0; i < drvdata->nr_cntr; i++) { etm4x_relaxed_write32(csa, config->cntrldvr[i], TRCCNTRLDVRn(i)); etm4x_relaxed_write32(csa, config->cntr_ctrl[i], TRCCNTCTLRn(i)); etm4x_relaxed_write32(csa, config->cntr_val[i], TRCCNTVRn(i)); } /* * Resource selector pair 0 is always implemented and reserved. As * such start at 2. */ for (i = 2; i < drvdata->nr_resource * 2; i++) etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i)); for (i = 0; i < drvdata->nr_ss_cmp; i++) { /* always clear status bit on restart if using single-shot */ if (config->ss_ctrl[i] || config->ss_pe_cmp[i]) config->ss_status[i] &= ~TRCSSCSRn_STATUS; etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i)); etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i)); if (etm4x_sspcicrn_present(drvdata, i)) etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i)); } for (i = 0; i < drvdata->nr_addr_cmp; i++) { etm4x_relaxed_write64(csa, config->addr_val[i], TRCACVRn(i)); etm4x_relaxed_write64(csa, config->addr_acc[i], TRCACATRn(i)); } for (i = 0; i < drvdata->numcidc; i++) etm4x_relaxed_write64(csa, config->ctxid_pid[i], TRCCIDCVRn(i)); etm4x_relaxed_write32(csa, config->ctxid_mask0, TRCCIDCCTLR0); if (drvdata->numcidc > 4) etm4x_relaxed_write32(csa, config->ctxid_mask1, TRCCIDCCTLR1); for (i = 0; i < drvdata->numvmidc; i++) etm4x_relaxed_write64(csa, config->vmid_val[i], TRCVMIDCVRn(i)); etm4x_relaxed_write32(csa, config->vmid_mask0, TRCVMIDCCTLR0); if (drvdata->numvmidc > 4) etm4x_relaxed_write32(csa, config->vmid_mask1, TRCVMIDCCTLR1); if (!drvdata->skip_power_up) { u32 trcpdcr = etm4x_relaxed_read32(csa, TRCPDCR); /* * Request to keep the trace unit powered and also * emulation of powerdown */ etm4x_relaxed_write32(csa, trcpdcr | TRCPDCR_PU, TRCPDCR); } /* * ETE mandates that the TRCRSR is written to before * enabling it. */ 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); /* Synchronize the register updates for sysreg access */ if (!csa->io_mem) isb(); /* wait for TRCSTATR.IDLE to go back down to '0' */ if (coresight_timeout(csa, TRCSTATR, TRCSTATR_IDLE_BIT, 0)) dev_err(etm_dev, "timeout while waiting for Idle Trace Status\n"); /* * As recommended by section 4.3.7 ("Synchronization when using the * memory-mapped interface") of ARM IHI 0064D */ dsb(sy); isb(); done: etm4_cs_lock(drvdata, csa); dev_dbg(etm_dev, "cpu: %d enable smp call done: %d\n", drvdata->cpu, rc); return rc; } static void etm4_enable_hw_smp_call(void *info) { struct etm4_enable_arg *arg = info; if (WARN_ON(!arg)) return; arg->rc = etm4_enable_hw(arg->drvdata); } /* * The goal of function etm4_config_timestamp_event() is to configure a * counter that will tell the tracer to emit a timestamp packet when it * reaches zero. This is done in order to get a more fine grained idea * of when instructions are executed so that they can be correlated * with execution on other CPUs. * * To do this the counter itself is configured to self reload and * TRCRSCTLR1 (always true) used to get the counter to decrement. From * there a resource selector is configured with the counter and the * timestamp control register to use the resource selector to trigger the * event that will insert a timestamp packet in the stream. */ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata) { int ctridx, ret = -EINVAL; int counter, rselector; u32 val = 0; struct etmv4_config *config = &drvdata->config; /* No point in trying if we don't have at least one counter */ if (!drvdata->nr_cntr) goto out; /* Find a counter that hasn't been initialised */ for (ctridx = 0; ctridx < drvdata->nr_cntr; ctridx++) if (config->cntr_val[ctridx] == 0) break; /* All the counters have been configured already, bail out */ if (ctridx == drvdata->nr_cntr) { pr_debug("%s: no available counter found\n", __func__); ret = -ENOSPC; goto out; } /* * Searching for an available resource selector to use, starting at * '2' since every implementation has at least 2 resource selector. * ETMIDR4 gives the number of resource selector _pairs_, * hence multiply by 2. */ for (rselector = 2; rselector < drvdata->nr_resource * 2; rselector++) if (!config->res_ctrl[rselector]) break; if (rselector == drvdata->nr_resource * 2) { pr_debug("%s: no available resource selector found\n", __func__); ret = -ENOSPC; goto out; } /* Remember what counter we used */ counter = 1 << ctridx; /* * Initialise original and reload counter value to the smallest * possible value in order to get as much precision as we can. */ config->cntr_val[ctridx] = 1; config->cntrldvr[ctridx] = 1; /* Set the trace counter control register */ val = 0x1 << 16 | /* Bit 16, reload counter automatically */ 0x0 << 7 | /* Select single resource selector */ 0x1; /* Resource selector 1, i.e always true */ config->cntr_ctrl[ctridx] = val; val = 0x2 << 16 | /* Group 0b0010 - Counter and sequencers */ counter << 0; /* Counter to use */ config->res_ctrl[rselector] = val; val = 0x0 << 7 | /* Select single resource selector */ rselector; /* Resource selector */ config->ts_ctrl = val; ret = 0; out: return ret; } static int etm4_parse_event_config(struct coresight_device *csdev, struct perf_event *event) { int ret = 0; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); struct etmv4_config *config = &drvdata->config; struct perf_event_attr *attr = &event->attr; unsigned long cfg_hash; int preset; /* Clear configuration from previous run */ memset(config, 0, sizeof(struct etmv4_config)); if (attr->exclude_kernel) config->mode = ETM_MODE_EXCL_KERN; if (attr->exclude_user) config->mode = ETM_MODE_EXCL_USER; /* Always start from the default config */ etm4_set_default_config(config); /* Configure filters specified on the perf cmd line, if any. */ ret = etm4_set_event_filters(drvdata, event); if (ret) goto out; /* Go from generic option to ETMv4 specifics */ if (attr->config & BIT(ETM_OPT_CYCACC)) { config->cfg |= TRCCONFIGR_CCI; /* TRM: Must program this for cycacc to work */ config->ccctlr = ETM_CYC_THRESHOLD_DEFAULT; } if (attr->config & BIT(ETM_OPT_TS)) { /* * Configure timestamps to be emitted at regular intervals in * order to correlate instructions executed on different CPUs * (CPU-wide trace scenarios). */ ret = etm4_config_timestamp_event(drvdata); /* * No need to go further if timestamp intervals can't * be configured. */ if (ret) goto out; /* bit[11], Global timestamp tracing bit */ config->cfg |= TRCCONFIGR_TS; } /* Only trace contextID when runs in root PID namespace */ if ((attr->config & BIT(ETM_OPT_CTXTID)) && task_is_in_init_pid_ns(current)) /* bit[6], Context ID tracing bit */ config->cfg |= TRCCONFIGR_CID; /* * If set bit ETM_OPT_CTXTID2 in perf config, this asks to trace VMID * for recording CONTEXTIDR_EL2. Do not enable VMID tracing if the * kernel is not running in EL2. */ if (attr->config & BIT(ETM_OPT_CTXTID2)) { if (!is_kernel_in_hyp_mode()) { ret = -EINVAL; goto out; } /* Only trace virtual contextID when runs in root PID namespace */ if (task_is_in_init_pid_ns(current)) config->cfg |= TRCCONFIGR_VMID | TRCCONFIGR_VMIDOPT; } /* return stack - enable if selected and supported */ if ((attr->config & BIT(ETM_OPT_RETSTK)) && drvdata->retstack) /* bit[12], Return stack enable bit */ config->cfg |= TRCCONFIGR_RS; /* * Set any selected configuration and preset. * * This extracts the values of PMU_FORMAT_ATTR(configid) and PMU_FORMAT_ATTR(preset) * in the perf attributes defined in coresight-etm-perf.c. * configid uses bits 63:32 of attr->config2, preset uses bits 3:0 of attr->config. * A zero configid means no configuration active, preset = 0 means no preset selected. */ if (attr->config2 & GENMASK_ULL(63, 32)) { cfg_hash = (u32)(attr->config2 >> 32); preset = attr->config & 0xF; ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset); } /* branch broadcast - enable if selected and supported */ if (attr->config & BIT(ETM_OPT_BRANCH_BROADCAST)) { if (!drvdata->trcbb) { /* * Missing BB support could cause silent decode errors * so fail to open if it's not supported. */ ret = -EINVAL; goto out; } else { config->cfg |= BIT(ETM4_CFG_BIT_BB); } } out: return ret; } static int etm4_enable_perf(struct coresight_device *csdev, struct perf_event *event) { int ret = 0; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) { ret = -EINVAL; goto out; } /* Configure the tracer based on the session's specifics */ ret = etm4_parse_event_config(csdev, event); if (ret) goto out; /* And enable it */ ret = etm4_enable_hw(drvdata); out: return ret; } static int etm4_enable_sysfs(struct coresight_device *csdev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); struct etm4_enable_arg arg = { }; unsigned long cfg_hash; int ret, preset; /* enable any config activated by configfs */ cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset); if (cfg_hash) { ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset); if (ret) return ret; } spin_lock(&drvdata->spinlock); /* * Executing etm4_enable_hw on the cpu whose ETM is being enabled * ensures that register writes occur when cpu is powered. */ arg.drvdata = drvdata; ret = smp_call_function_single(drvdata->cpu, etm4_enable_hw_smp_call, &arg, 1); if (!ret) ret = arg.rc; if (!ret) drvdata->sticky_enable = true; spin_unlock(&drvdata->spinlock); if (!ret) dev_dbg(&csdev->dev, "ETM tracing enabled\n"); return ret; } static int etm4_enable(struct coresight_device *csdev, struct perf_event *event, u32 mode) { int ret; u32 val; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode); /* Someone is already using the tracer */ if (val) return -EBUSY; switch (mode) { case CS_MODE_SYSFS: ret = etm4_enable_sysfs(csdev); break; case CS_MODE_PERF: ret = etm4_enable_perf(csdev, event); break; default: ret = -EINVAL; } /* The tracer didn't start */ if (ret) local_set(&drvdata->mode, CS_MODE_DISABLED); return ret; } static void etm4_disable_hw(void *info) { u32 control; struct etmv4_drvdata *drvdata = info; struct etmv4_config *config = &drvdata->config; struct coresight_device *csdev = drvdata->csdev; struct device *etm_dev = &csdev->dev; struct csdev_access *csa = &csdev->access; int i; etm4_cs_unlock(drvdata, csa); etm4_disable_arch_specific(drvdata); if (!drvdata->skip_power_up) { /* power can be removed from the trace unit now */ control = etm4x_relaxed_read32(csa, TRCPDCR); control &= ~TRCPDCR_PU; etm4x_relaxed_write32(csa, control, TRCPDCR); } control = etm4x_relaxed_read32(csa, TRCPRGCTLR); /* EN, bit[0] Trace unit enable bit */ control &= ~0x1; /* * If the CPU supports v8.4 Trace filter Control, * set the ETM to trace prohibited region. */ etm4x_prohibit_trace(drvdata); /* * Make sure everything completes before disabling, as recommended * by section 7.3.77 ("TRCVICTLR, ViewInst Main Control Register, * SSTATUS") of ARM IHI 0064D */ dsb(sy); isb(); /* Trace synchronization barrier, is a nop if not supported */ tsb_csync(); etm4x_relaxed_write32(csa, control, TRCPRGCTLR); /* wait for TRCSTATR.PMSTABLE to go to '1' */ if (coresight_timeout(csa, TRCSTATR, TRCSTATR_PMSTABLE_BIT, 1)) dev_err(etm_dev, "timeout while waiting for PM stable Trace Status\n"); /* read the status of the single shot comparators */ for (i = 0; i < drvdata->nr_ss_cmp; i++) { config->ss_status[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i)); } /* read back the current counter values */ for (i = 0; i < drvdata->nr_cntr; i++) { config->cntr_val[i] = etm4x_relaxed_read32(csa, TRCCNTVRn(i)); } coresight_disclaim_device_unlocked(csdev); etm4_cs_lock(drvdata, csa); dev_dbg(&drvdata->csdev->dev, "cpu: %d disable smp call done\n", drvdata->cpu); } static int etm4_disable_perf(struct coresight_device *csdev, struct perf_event *event) { u32 control; struct etm_filters *filters = event->hw.addr_filters; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); struct perf_event_attr *attr = &event->attr; if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) return -EINVAL; etm4_disable_hw(drvdata); /* * The config_id occupies bits 63:32 of the config2 perf event attr * field. If this is non-zero then we will have enabled a config. */ if (attr->config2 & GENMASK_ULL(63, 32)) cscfg_csdev_disable_active_config(csdev); /* * Check if the start/stop logic was active when the unit was stopped. * That way we can re-enable the start/stop logic when the process is * scheduled again. Configuration of the start/stop logic happens in * function etm4_set_event_filters(). */ control = etm4x_relaxed_read32(&csdev->access, TRCVICTLR); /* TRCVICTLR::SSSTATUS, bit[9] */ filters->ssstatus = (control & BIT(9)); return 0; } static void etm4_disable_sysfs(struct coresight_device *csdev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); /* * Taking hotplug lock here protects from clocks getting disabled * with tracing being left on (crash scenario) if user disable occurs * after cpu online mask indicates the cpu is offline but before the * DYING hotplug callback is serviced by the ETM driver. */ cpus_read_lock(); spin_lock(&drvdata->spinlock); /* * Executing etm4_disable_hw on the cpu whose ETM is being disabled * ensures that register writes occur when cpu is powered. */ smp_call_function_single(drvdata->cpu, etm4_disable_hw, drvdata, 1); spin_unlock(&drvdata->spinlock); cpus_read_unlock(); dev_dbg(&csdev->dev, "ETM tracing disabled\n"); } static void etm4_disable(struct coresight_device *csdev, struct perf_event *event) { u32 mode; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); /* * For as long as the tracer isn't disabled another entity can't * change its status. As such we can read the status here without * fearing it will change under us. */ mode = local_read(&drvdata->mode); switch (mode) { case CS_MODE_DISABLED: break; case CS_MODE_SYSFS: etm4_disable_sysfs(csdev); break; case CS_MODE_PERF: etm4_disable_perf(csdev, event); break; } if (mode) local_set(&drvdata->mode, CS_MODE_DISABLED); } static const struct coresight_ops_source etm4_source_ops = { .cpu_id = etm4_cpu_id, .trace_id = etm4_trace_id, .enable = etm4_enable, .disable = etm4_disable, }; static const struct coresight_ops etm4_cs_ops = { .source_ops = &etm4_source_ops, }; static inline bool cpu_supports_sysreg_trace(void) { u64 dfr0 = read_sysreg_s(SYS_ID_AA64DFR0_EL1); return ((dfr0 >> ID_AA64DFR0_EL1_TraceVer_SHIFT) & 0xfUL) > 0; } static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { u32 devarch; if (!cpu_supports_sysreg_trace()) return false; /* * ETMs implementing sysreg access must implement TRCDEVARCH. */ devarch = read_etm4x_sysreg_const_offset(TRCDEVARCH); switch (devarch & ETM_DEVARCH_ID_MASK) { case ETM_DEVARCH_ETMv4x_ARCH: *csa = (struct csdev_access) { .io_mem = false, .read = etm4x_sysreg_read, .write = etm4x_sysreg_write, }; break; case ETM_DEVARCH_ETE_ARCH: *csa = (struct csdev_access) { .io_mem = false, .read = ete_sysreg_read, .write = ete_sysreg_write, }; break; default: return false; } drvdata->arch = etm_devarch_to_arch(devarch); return true; } static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { u32 devarch = readl_relaxed(drvdata->base + TRCDEVARCH); u32 idr1 = readl_relaxed(drvdata->base + TRCIDR1); /* * All ETMs must implement TRCDEVARCH to indicate that * the component is an ETMv4. To support any broken * implementations we fall back to TRCIDR1 check, which * is not really reliable. */ if ((devarch & ETM_DEVARCH_ID_MASK) == ETM_DEVARCH_ETMv4x_ARCH) { drvdata->arch = etm_devarch_to_arch(devarch); } else { pr_warn("CPU%d: ETM4x incompatible TRCDEVARCH: %x, falling back to TRCIDR1\n", smp_processor_id(), devarch); if (ETM_TRCIDR1_ARCH_MAJOR(idr1) != ETM_TRCIDR1_ARCH_ETMv4) return false; drvdata->arch = etm_trcidr_to_arch(idr1); } *csa = CSDEV_ACCESS_IOMEM(drvdata->base); return true; } static bool etm4_init_csdev_access(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { /* * Always choose the memory mapped io, if there is * a memory map to prevent sysreg access on broken * systems. */ if (drvdata->base) return etm4_init_iomem_access(drvdata, csa); if (etm4_init_sysreg_access(drvdata, csa)) return true; return false; } 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_EL1_TraceFilt_SHIFT)) return; /* * If the CPU supports v8.4 SelfHosted Tracing, enable * tracing at the kernel EL and EL0, forcing to use the * virtual time as the timestamp. */ trfcr = (TRFCR_ELx_TS_VIRTUAL | TRFCR_ELx_ExTRE | TRFCR_ELx_E0TRE); /* If we are running at EL2, allow tracing the CONTEXTIDR_EL2. */ if (is_kernel_in_hyp_mode()) trfcr |= TRFCR_EL2_CX; drvdata->trfcr = trfcr; } static void etm4_init_arch_data(void *info) { u32 etmidr0; u32 etmidr2; u32 etmidr3; u32 etmidr4; u32 etmidr5; struct etm4_init_arg *init_arg = info; struct etmv4_drvdata *drvdata; struct csdev_access *csa; int i; drvdata = init_arg->drvdata; csa = init_arg->csa; /* * If we are unable to detect the access mechanism, * or unable to detect the trace unit type, fail * early. */ if (!etm4_init_csdev_access(drvdata, csa)) return; /* Detect the support for OS Lock before we actually use it */ etm_detect_os_lock(drvdata, csa); /* Make sure all registers are accessible */ etm4_os_unlock_csa(drvdata, csa); etm4_cs_unlock(drvdata, csa); etm4_check_arch_features(drvdata, init_arg->pid); /* find all capabilities of the tracing unit */ etmidr0 = etm4x_relaxed_read32(csa, TRCIDR0); /* INSTP0, bits[2:1] P0 tracing support field */ drvdata->instrp0 = !!(FIELD_GET(TRCIDR0_INSTP0_MASK, etmidr0) == 0b11); /* TRCBB, bit[5] Branch broadcast tracing support bit */ drvdata->trcbb = !!(etmidr0 & TRCIDR0_TRCBB); /* TRCCOND, bit[6] Conditional instruction tracing support bit */ drvdata->trccond = !!(etmidr0 & TRCIDR0_TRCCOND); /* TRCCCI, bit[7] Cycle counting instruction bit */ drvdata->trccci = !!(etmidr0 & TRCIDR0_TRCCCI); /* RETSTACK, bit[9] Return stack bit */ drvdata->retstack = !!(etmidr0 & TRCIDR0_RETSTACK); /* NUMEVENT, bits[11:10] Number of events field */ drvdata->nr_event = FIELD_GET(TRCIDR0_NUMEVENT_MASK, etmidr0); /* QSUPP, bits[16:15] Q element support field */ drvdata->q_support = FIELD_GET(TRCIDR0_QSUPP_MASK, etmidr0); /* TSSIZE, bits[28:24] Global timestamp size field */ drvdata->ts_size = FIELD_GET(TRCIDR0_TSSIZE_MASK, etmidr0); /* maximum size of resources */ etmidr2 = etm4x_relaxed_read32(csa, TRCIDR2); /* CIDSIZE, bits[9:5] Indicates the Context ID size */ drvdata->ctxid_size = FIELD_GET(TRCIDR2_CIDSIZE_MASK, etmidr2); /* VMIDSIZE, bits[14:10] Indicates the VMID size */ drvdata->vmid_size = FIELD_GET(TRCIDR2_VMIDSIZE_MASK, etmidr2); /* CCSIZE, bits[28:25] size of the cycle counter in bits minus 12 */ drvdata->ccsize = FIELD_GET(TRCIDR2_CCSIZE_MASK, etmidr2); etmidr3 = etm4x_relaxed_read32(csa, TRCIDR3); /* CCITMIN, bits[11:0] minimum threshold value that can be programmed */ drvdata->ccitmin = FIELD_GET(TRCIDR3_CCITMIN_MASK, etmidr3); /* EXLEVEL_S, bits[19:16] Secure state instruction tracing */ drvdata->s_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_S_MASK, etmidr3); drvdata->config.s_ex_level = drvdata->s_ex_level; /* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */ drvdata->ns_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_NS_MASK, etmidr3); /* * TRCERR, bit[24] whether a trace unit can trace a * system error exception. */ drvdata->trc_error = !!(etmidr3 & TRCIDR3_TRCERR); /* SYNCPR, bit[25] implementation has a fixed synchronization period? */ drvdata->syncpr = !!(etmidr3 & TRCIDR3_SYNCPR); /* STALLCTL, bit[26] is stall control implemented? */ drvdata->stallctl = !!(etmidr3 & TRCIDR3_STALLCTL); /* SYSSTALL, bit[27] implementation can support stall control? */ drvdata->sysstall = !!(etmidr3 & TRCIDR3_SYSSTALL); /* * NUMPROC - the number of PEs available for tracing, 5bits * = TRCIDR3.bits[13:12]bits[30:28] * bits[4:3] = TRCIDR3.bits[13:12] (since etm-v4.2, otherwise RES0) * bits[3:0] = TRCIDR3.bits[30:28] */ drvdata->nr_pe = (FIELD_GET(TRCIDR3_NUMPROC_HI_MASK, etmidr3) << 3) | FIELD_GET(TRCIDR3_NUMPROC_LO_MASK, etmidr3); /* NOOVERFLOW, bit[31] is trace overflow prevention supported */ drvdata->nooverflow = !!(etmidr3 & TRCIDR3_NOOVERFLOW); /* number of resources trace unit supports */ etmidr4 = etm4x_relaxed_read32(csa, TRCIDR4); /* NUMACPAIRS, bits[0:3] number of addr comparator pairs for tracing */ drvdata->nr_addr_cmp = FIELD_GET(TRCIDR4_NUMACPAIRS_MASK, etmidr4); /* NUMPC, bits[15:12] number of PE comparator inputs for tracing */ drvdata->nr_pe_cmp = FIELD_GET(TRCIDR4_NUMPC_MASK, etmidr4); /* * NUMRSPAIR, bits[19:16] * The number of resource pairs conveyed by the HW starts at 0, i.e a * value of 0x0 indicate 1 resource pair, 0x1 indicate two and so on. * As such add 1 to the value of NUMRSPAIR for a better representation. * * For ETM v4.3 and later, 0x0 means 0, and no pairs are available - * the default TRUE and FALSE resource selectors are omitted. * Otherwise for values 0x1 and above the number is N + 1 as per v4.2. */ drvdata->nr_resource = FIELD_GET(TRCIDR4_NUMRSPAIR_MASK, etmidr4); if ((drvdata->arch < ETM_ARCH_V4_3) || (drvdata->nr_resource > 0)) drvdata->nr_resource += 1; /* * NUMSSCC, bits[23:20] the number of single-shot * comparator control for tracing. Read any status regs as these * also contain RO capability data. */ drvdata->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4); for (i = 0; i < drvdata->nr_ss_cmp; i++) { drvdata->config.ss_status[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i)); } /* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */ drvdata->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4); /* NUMVMIDC, bits[31:28] number of VMID comparators for tracing */ drvdata->numvmidc = FIELD_GET(TRCIDR4_NUMVMIDC_MASK, etmidr4); etmidr5 = etm4x_relaxed_read32(csa, TRCIDR5); /* NUMEXTIN, bits[8:0] number of external inputs implemented */ drvdata->nr_ext_inp = FIELD_GET(TRCIDR5_NUMEXTIN_MASK, etmidr5); /* TRACEIDSIZE, bits[21:16] indicates the trace ID width */ drvdata->trcid_size = FIELD_GET(TRCIDR5_TRACEIDSIZE_MASK, etmidr5); /* ATBTRIG, bit[22] implementation can support ATB triggers? */ drvdata->atbtrig = !!(etmidr5 & TRCIDR5_ATBTRIG); /* * LPOVERRIDE, bit[23] implementation supports * low-power state override */ drvdata->lpoverride = (etmidr5 & TRCIDR5_LPOVERRIDE) && (!drvdata->skip_power_up); /* NUMSEQSTATE, bits[27:25] number of sequencer states implemented */ drvdata->nrseqstate = FIELD_GET(TRCIDR5_NUMSEQSTATE_MASK, etmidr5); /* NUMCNTR, bits[30:28] number of counters available for tracing */ drvdata->nr_cntr = FIELD_GET(TRCIDR5_NUMCNTR_MASK, etmidr5); etm4_cs_lock(drvdata, csa); cpu_detect_trace_filtering(drvdata); } static inline u32 etm4_get_victlr_access_type(struct etmv4_config *config) { return etm4_get_access_type(config) << __bf_shf(TRCVICTLR_EXLEVEL_MASK); } /* Set ELx trace filter access in the TRCVICTLR register */ static void etm4_set_victlr_access(struct etmv4_config *config) { config->vinst_ctrl &= ~TRCVICTLR_EXLEVEL_MASK; config->vinst_ctrl |= etm4_get_victlr_access_type(config); } static void etm4_set_default_config(struct etmv4_config *config) { /* disable all events tracing */ config->eventctrl0 = 0x0; config->eventctrl1 = 0x0; /* disable stalling */ config->stall_ctrl = 0x0; /* enable trace synchronization every 4096 bytes, if available */ config->syncfreq = 0xC; /* disable timestamp event */ config->ts_ctrl = 0x0; /* TRCVICTLR::EVENT = 0x01, select the always on logic */ config->vinst_ctrl = FIELD_PREP(TRCVICTLR_EVENT_MASK, 0x01); /* TRCVICTLR::EXLEVEL_NS:EXLEVELS: Set kernel / user filtering */ etm4_set_victlr_access(config); } static u64 etm4_get_ns_access_type(struct etmv4_config *config) { u64 access_type = 0; /* * EXLEVEL_NS, for NonSecure Exception levels. * The mask here is a generic value and must be * shifted to the corresponding field for the registers */ if (!is_kernel_in_hyp_mode()) { /* Stay away from hypervisor mode for non-VHE */ access_type = ETM_EXLEVEL_NS_HYP; if (config->mode & ETM_MODE_EXCL_KERN) access_type |= ETM_EXLEVEL_NS_OS; } else if (config->mode & ETM_MODE_EXCL_KERN) { access_type = ETM_EXLEVEL_NS_HYP; } if (config->mode & ETM_MODE_EXCL_USER) access_type |= ETM_EXLEVEL_NS_APP; return access_type; } /* * Construct the exception level masks for a given config. * This must be shifted to the corresponding register field * for usage. */ static u64 etm4_get_access_type(struct etmv4_config *config) { /* All Secure exception levels are excluded from the trace */ return etm4_get_ns_access_type(config) | (u64)config->s_ex_level; } static u64 etm4_get_comparator_access_type(struct etmv4_config *config) { return etm4_get_access_type(config) << TRCACATR_EXLEVEL_SHIFT; } static void etm4_set_comparator_filter(struct etmv4_config *config, u64 start, u64 stop, int comparator) { u64 access_type = etm4_get_comparator_access_type(config); /* First half of default address comparator */ config->addr_val[comparator] = start; config->addr_acc[comparator] = access_type; config->addr_type[comparator] = ETM_ADDR_TYPE_RANGE; /* Second half of default address comparator */ config->addr_val[comparator + 1] = stop; config->addr_acc[comparator + 1] = access_type; config->addr_type[comparator + 1] = ETM_ADDR_TYPE_RANGE; /* * Configure the ViewInst function to include this address range * comparator. * * @comparator is divided by two since it is the index in the * etmv4_config::addr_val array but register TRCVIIECTLR deals with * address range comparator _pairs_. * * Therefore: * index 0 -> compatator pair 0 * index 2 -> comparator pair 1 * index 4 -> comparator pair 2 * ... * index 14 -> comparator pair 7 */ config->viiectlr |= BIT(comparator / 2); } static void etm4_set_start_stop_filter(struct etmv4_config *config, u64 address, int comparator, enum etm_addr_type type) { int shift; u64 access_type = etm4_get_comparator_access_type(config); /* Configure the comparator */ config->addr_val[comparator] = address; config->addr_acc[comparator] = access_type; config->addr_type[comparator] = type; /* * Configure ViewInst Start-Stop control register. * Addresses configured to start tracing go from bit 0 to n-1, * while those configured to stop tracing from 16 to 16 + n-1. */ shift = (type == ETM_ADDR_TYPE_START ? 0 : 16); config->vissctlr |= BIT(shift + comparator); } static void etm4_set_default_filter(struct etmv4_config *config) { /* Trace everything 'default' filter achieved by no filtering */ config->viiectlr = 0x0; /* * TRCVICTLR::SSSTATUS == 1, the start-stop logic is * in the started state */ config->vinst_ctrl |= TRCVICTLR_SSSTATUS; config->mode |= ETM_MODE_VIEWINST_STARTSTOP; /* No start-stop filtering for ViewInst */ config->vissctlr = 0x0; } static void etm4_set_default(struct etmv4_config *config) { if (WARN_ON_ONCE(!config)) return; /* * Make default initialisation trace everything * * This is done by a minimum default config sufficient to enable * full instruction trace - with a default filter for trace all * achieved by having no filtering. */ etm4_set_default_config(config); etm4_set_default_filter(config); } static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type) { int nr_comparator, index = 0; struct etmv4_config *config = &drvdata->config; /* * nr_addr_cmp holds the number of comparator _pair_, so time 2 * for the total number of comparators. */ nr_comparator = drvdata->nr_addr_cmp * 2; /* Go through the tally of comparators looking for a free one. */ while (index < nr_comparator) { switch (type) { case ETM_ADDR_TYPE_RANGE: if (config->addr_type[index] == ETM_ADDR_TYPE_NONE && config->addr_type[index + 1] == ETM_ADDR_TYPE_NONE) return index; /* Address range comparators go in pairs */ index += 2; break; case ETM_ADDR_TYPE_START: case ETM_ADDR_TYPE_STOP: if (config->addr_type[index] == ETM_ADDR_TYPE_NONE) return index; /* Start/stop address can have odd indexes */ index += 1; break; default: return -EINVAL; } } /* If we are here all the comparators have been used. */ return -ENOSPC; } static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, struct perf_event *event) { int i, comparator, ret = 0; u64 address; struct etmv4_config *config = &drvdata->config; struct etm_filters *filters = event->hw.addr_filters; if (!filters) goto default_filter; /* Sync events with what Perf got */ perf_event_addr_filters_sync(event); /* * If there are no filters to deal with simply go ahead with * the default filter, i.e the entire address range. */ if (!filters->nr_filters) goto default_filter; for (i = 0; i < filters->nr_filters; i++) { struct etm_filter *filter = &filters->etm_filter[i]; enum etm_addr_type type = filter->type; /* See if a comparator is free. */ comparator = etm4_get_next_comparator(drvdata, type); if (comparator < 0) { ret = comparator; goto out; } switch (type) { case ETM_ADDR_TYPE_RANGE: etm4_set_comparator_filter(config, filter->start_addr, filter->stop_addr, comparator); /* * TRCVICTLR::SSSTATUS == 1, the start-stop logic is * in the started state */ config->vinst_ctrl |= TRCVICTLR_SSSTATUS; /* No start-stop filtering for ViewInst */ config->vissctlr = 0x0; break; case ETM_ADDR_TYPE_START: case ETM_ADDR_TYPE_STOP: /* Get the right start or stop address */ address = (type == ETM_ADDR_TYPE_START ? filter->start_addr : filter->stop_addr); /* Configure comparator */ etm4_set_start_stop_filter(config, address, comparator, type); /* * If filters::ssstatus == 1, trace acquisition was * started but the process was yanked away before the * the stop address was hit. As such the start/stop * logic needs to be re-started so that tracing can * resume where it left. * * The start/stop logic status when a process is * scheduled out is checked in function * etm4_disable_perf(). */ if (filters->ssstatus) config->vinst_ctrl |= TRCVICTLR_SSSTATUS; /* No include/exclude filtering for ViewInst */ config->viiectlr = 0x0; break; default: ret = -EINVAL; goto out; } } goto out; default_filter: etm4_set_default_filter(config); out: return ret; } void etm4_config_trace_mode(struct etmv4_config *config) { u32 mode; mode = config->mode; mode &= (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER); /* excluding kernel AND user space doesn't make sense */ WARN_ON_ONCE(mode == (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER)); /* nothing to do if neither flags are set */ if (!(mode & ETM_MODE_EXCL_KERN) && !(mode & ETM_MODE_EXCL_USER)) return; etm4_set_victlr_access(config); } static int etm4_online_cpu(unsigned int cpu) { if (!etmdrvdata[cpu]) return 0; if (etmdrvdata[cpu]->boot_enable && !etmdrvdata[cpu]->sticky_enable) coresight_enable(etmdrvdata[cpu]->csdev); return 0; } static int etm4_starting_cpu(unsigned int cpu) { if (!etmdrvdata[cpu]) return 0; spin_lock(&etmdrvdata[cpu]->spinlock); if (!etmdrvdata[cpu]->os_unlock) etm4_os_unlock(etmdrvdata[cpu]); if (local_read(&etmdrvdata[cpu]->mode)) etm4_enable_hw(etmdrvdata[cpu]); spin_unlock(&etmdrvdata[cpu]->spinlock); return 0; } static int etm4_dying_cpu(unsigned int cpu) { if (!etmdrvdata[cpu]) return 0; spin_lock(&etmdrvdata[cpu]->spinlock); if (local_read(&etmdrvdata[cpu]->mode)) etm4_disable_hw(etmdrvdata[cpu]); spin_unlock(&etmdrvdata[cpu]->spinlock); return 0; } static void etm4_init_trace_id(struct etmv4_drvdata *drvdata) { drvdata->trcid = coresight_get_trace_id(drvdata->cpu); } static int __etm4_cpu_save(struct etmv4_drvdata *drvdata) { int i, ret = 0; struct etmv4_save_state *state; struct coresight_device *csdev = drvdata->csdev; struct csdev_access *csa; struct device *etm_dev; if (WARN_ON(!csdev)) return -ENODEV; etm_dev = &csdev->dev; csa = &csdev->access; /* * As recommended by 3.4.1 ("The procedure when powering down the PE") * of ARM IHI 0064D */ dsb(sy); isb(); etm4_cs_unlock(drvdata, csa); /* Lock the OS lock to disable trace and external debugger access */ etm4_os_lock(drvdata); /* wait for TRCSTATR.PMSTABLE to go up */ if (coresight_timeout(csa, TRCSTATR, TRCSTATR_PMSTABLE_BIT, 1)) { dev_err(etm_dev, "timeout while waiting for PM Stable Status\n"); etm4_os_unlock(drvdata); ret = -EBUSY; goto out; } state = drvdata->save_state; state->trcprgctlr = etm4x_read32(csa, TRCPRGCTLR); if (drvdata->nr_pe) state->trcprocselr = etm4x_read32(csa, TRCPROCSELR); state->trcconfigr = etm4x_read32(csa, TRCCONFIGR); state->trcauxctlr = etm4x_read32(csa, TRCAUXCTLR); state->trceventctl0r = etm4x_read32(csa, TRCEVENTCTL0R); state->trceventctl1r = etm4x_read32(csa, TRCEVENTCTL1R); if (drvdata->stallctl) state->trcstallctlr = etm4x_read32(csa, TRCSTALLCTLR); state->trctsctlr = etm4x_read32(csa, TRCTSCTLR); state->trcsyncpr = etm4x_read32(csa, TRCSYNCPR); state->trcccctlr = etm4x_read32(csa, TRCCCCTLR); state->trcbbctlr = etm4x_read32(csa, TRCBBCTLR); state->trctraceidr = etm4x_read32(csa, TRCTRACEIDR); state->trcqctlr = etm4x_read32(csa, TRCQCTLR); state->trcvictlr = etm4x_read32(csa, TRCVICTLR); state->trcviiectlr = etm4x_read32(csa, TRCVIIECTLR); state->trcvissctlr = etm4x_read32(csa, TRCVISSCTLR); if (drvdata->nr_pe_cmp) state->trcvipcssctlr = etm4x_read32(csa, TRCVIPCSSCTLR); state->trcvdctlr = etm4x_read32(csa, TRCVDCTLR); state->trcvdsacctlr = etm4x_read32(csa, TRCVDSACCTLR); state->trcvdarcctlr = etm4x_read32(csa, TRCVDARCCTLR); for (i = 0; i < drvdata->nrseqstate - 1; i++) state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i)); state->trcseqrstevr = etm4x_read32(csa, TRCSEQRSTEVR); state->trcseqstr = etm4x_read32(csa, TRCSEQSTR); state->trcextinselr = etm4x_read32(csa, TRCEXTINSELR); for (i = 0; i < drvdata->nr_cntr; i++) { state->trccntrldvr[i] = etm4x_read32(csa, TRCCNTRLDVRn(i)); state->trccntctlr[i] = etm4x_read32(csa, TRCCNTCTLRn(i)); state->trccntvr[i] = etm4x_read32(csa, TRCCNTVRn(i)); } for (i = 0; i < drvdata->nr_resource * 2; i++) state->trcrsctlr[i] = etm4x_read32(csa, TRCRSCTLRn(i)); for (i = 0; i < drvdata->nr_ss_cmp; i++) { state->trcssccr[i] = etm4x_read32(csa, TRCSSCCRn(i)); state->trcsscsr[i] = etm4x_read32(csa, TRCSSCSRn(i)); if (etm4x_sspcicrn_present(drvdata, i)) state->trcsspcicr[i] = etm4x_read32(csa, TRCSSPCICRn(i)); } for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) { state->trcacvr[i] = etm4x_read64(csa, TRCACVRn(i)); state->trcacatr[i] = etm4x_read64(csa, TRCACATRn(i)); } /* * Data trace stream is architecturally prohibited for A profile cores * so we don't save (or later restore) trcdvcvr and trcdvcmr - As per * section 1.3.4 ("Possible functional configurations of an ETMv4 trace * unit") of ARM IHI 0064D. */ for (i = 0; i < drvdata->numcidc; i++) state->trccidcvr[i] = etm4x_read64(csa, TRCCIDCVRn(i)); for (i = 0; i < drvdata->numvmidc; i++) state->trcvmidcvr[i] = etm4x_read64(csa, TRCVMIDCVRn(i)); state->trccidcctlr0 = etm4x_read32(csa, TRCCIDCCTLR0); if (drvdata->numcidc > 4) state->trccidcctlr1 = etm4x_read32(csa, TRCCIDCCTLR1); state->trcvmidcctlr0 = etm4x_read32(csa, TRCVMIDCCTLR0); if (drvdata->numvmidc > 4) state->trcvmidcctlr0 = etm4x_read32(csa, TRCVMIDCCTLR1); state->trcclaimset = etm4x_read32(csa, TRCCLAIMCLR); if (!drvdata->skip_power_up) state->trcpdcr = etm4x_read32(csa, TRCPDCR); /* wait for TRCSTATR.IDLE to go up */ if (coresight_timeout(csa, TRCSTATR, TRCSTATR_IDLE_BIT, 1)) { dev_err(etm_dev, "timeout while waiting for Idle Trace Status\n"); etm4_os_unlock(drvdata); ret = -EBUSY; goto out; } drvdata->state_needs_restore = true; /* * Power can be removed from the trace unit now. We do this to * potentially save power on systems that respect the TRCPDCR_PU * despite requesting software to save/restore state. */ if (!drvdata->skip_power_up) etm4x_relaxed_write32(csa, (state->trcpdcr & ~TRCPDCR_PU), TRCPDCR); out: etm4_cs_lock(drvdata, csa); return ret; } static int etm4_cpu_save(struct etmv4_drvdata *drvdata) { int ret = 0; /* Save the TRFCR irrespective of whether the ETM is ON */ if (drvdata->trfcr) drvdata->save_trfcr = read_trfcr(); /* * Save and restore the ETM Trace registers only if * the ETM is active. */ if (local_read(&drvdata->mode) && drvdata->save_state) ret = __etm4_cpu_save(drvdata); return ret; } static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata) { int i; struct etmv4_save_state *state = drvdata->save_state; struct csdev_access tmp_csa = CSDEV_ACCESS_IOMEM(drvdata->base); struct csdev_access *csa = &tmp_csa; etm4_cs_unlock(drvdata, csa); etm4x_relaxed_write32(csa, state->trcclaimset, TRCCLAIMSET); etm4x_relaxed_write32(csa, state->trcprgctlr, TRCPRGCTLR); if (drvdata->nr_pe) etm4x_relaxed_write32(csa, state->trcprocselr, TRCPROCSELR); etm4x_relaxed_write32(csa, state->trcconfigr, TRCCONFIGR); etm4x_relaxed_write32(csa, state->trcauxctlr, TRCAUXCTLR); etm4x_relaxed_write32(csa, state->trceventctl0r, TRCEVENTCTL0R); etm4x_relaxed_write32(csa, state->trceventctl1r, TRCEVENTCTL1R); if (drvdata->stallctl) etm4x_relaxed_write32(csa, state->trcstallctlr, TRCSTALLCTLR); etm4x_relaxed_write32(csa, state->trctsctlr, TRCTSCTLR); etm4x_relaxed_write32(csa, state->trcsyncpr, TRCSYNCPR); etm4x_relaxed_write32(csa, state->trcccctlr, TRCCCCTLR); etm4x_relaxed_write32(csa, state->trcbbctlr, TRCBBCTLR); etm4x_relaxed_write32(csa, state->trctraceidr, TRCTRACEIDR); etm4x_relaxed_write32(csa, state->trcqctlr, TRCQCTLR); etm4x_relaxed_write32(csa, state->trcvictlr, TRCVICTLR); etm4x_relaxed_write32(csa, state->trcviiectlr, TRCVIIECTLR); etm4x_relaxed_write32(csa, state->trcvissctlr, TRCVISSCTLR); if (drvdata->nr_pe_cmp) etm4x_relaxed_write32(csa, state->trcvipcssctlr, TRCVIPCSSCTLR); etm4x_relaxed_write32(csa, state->trcvdctlr, TRCVDCTLR); etm4x_relaxed_write32(csa, state->trcvdsacctlr, TRCVDSACCTLR); etm4x_relaxed_write32(csa, state->trcvdarcctlr, TRCVDARCCTLR); for (i = 0; i < drvdata->nrseqstate - 1; i++) etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i)); etm4x_relaxed_write32(csa, state->trcseqrstevr, TRCSEQRSTEVR); etm4x_relaxed_write32(csa, state->trcseqstr, TRCSEQSTR); etm4x_relaxed_write32(csa, state->trcextinselr, TRCEXTINSELR); for (i = 0; i < drvdata->nr_cntr; i++) { etm4x_relaxed_write32(csa, state->trccntrldvr[i], TRCCNTRLDVRn(i)); etm4x_relaxed_write32(csa, state->trccntctlr[i], TRCCNTCTLRn(i)); etm4x_relaxed_write32(csa, state->trccntvr[i], TRCCNTVRn(i)); } for (i = 0; i < drvdata->nr_resource * 2; i++) etm4x_relaxed_write32(csa, state->trcrsctlr[i], TRCRSCTLRn(i)); for (i = 0; i < drvdata->nr_ss_cmp; i++) { etm4x_relaxed_write32(csa, state->trcssccr[i], TRCSSCCRn(i)); etm4x_relaxed_write32(csa, state->trcsscsr[i], TRCSSCSRn(i)); if (etm4x_sspcicrn_present(drvdata, i)) etm4x_relaxed_write32(csa, state->trcsspcicr[i], TRCSSPCICRn(i)); } for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) { etm4x_relaxed_write64(csa, state->trcacvr[i], TRCACVRn(i)); etm4x_relaxed_write64(csa, state->trcacatr[i], TRCACATRn(i)); } for (i = 0; i < drvdata->numcidc; i++) etm4x_relaxed_write64(csa, state->trccidcvr[i], TRCCIDCVRn(i)); for (i = 0; i < drvdata->numvmidc; i++) etm4x_relaxed_write64(csa, state->trcvmidcvr[i], TRCVMIDCVRn(i)); etm4x_relaxed_write32(csa, state->trccidcctlr0, TRCCIDCCTLR0); if (drvdata->numcidc > 4) etm4x_relaxed_write32(csa, state->trccidcctlr1, TRCCIDCCTLR1); etm4x_relaxed_write32(csa, state->trcvmidcctlr0, TRCVMIDCCTLR0); if (drvdata->numvmidc > 4) etm4x_relaxed_write32(csa, state->trcvmidcctlr0, TRCVMIDCCTLR1); etm4x_relaxed_write32(csa, state->trcclaimset, TRCCLAIMSET); if (!drvdata->skip_power_up) etm4x_relaxed_write32(csa, state->trcpdcr, TRCPDCR); drvdata->state_needs_restore = false; /* * As recommended by section 4.3.7 ("Synchronization when using the * memory-mapped interface") of ARM IHI 0064D */ dsb(sy); isb(); /* Unlock the OS lock to re-enable trace and external debug access */ etm4_os_unlock(drvdata); etm4_cs_lock(drvdata, csa); } static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) { if (drvdata->trfcr) write_trfcr(drvdata->save_trfcr); if (drvdata->state_needs_restore) __etm4_cpu_restore(drvdata); } static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, void *v) { struct etmv4_drvdata *drvdata; unsigned int cpu = smp_processor_id(); if (!etmdrvdata[cpu]) return NOTIFY_OK; drvdata = etmdrvdata[cpu]; if (WARN_ON_ONCE(drvdata->cpu != cpu)) return NOTIFY_BAD; switch (cmd) { case CPU_PM_ENTER: if (etm4_cpu_save(drvdata)) return NOTIFY_BAD; break; case CPU_PM_EXIT: case CPU_PM_ENTER_FAILED: etm4_cpu_restore(drvdata); break; default: return NOTIFY_DONE; } return NOTIFY_OK; } static struct notifier_block etm4_cpu_pm_nb = { .notifier_call = etm4_cpu_pm_notify, }; /* Setup PM. Deals with error conditions and counts */ static int __init etm4_pm_setup(void) { int ret; ret = cpu_pm_register_notifier(&etm4_cpu_pm_nb); if (ret) return ret; ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING, "arm/coresight4:starting", etm4_starting_cpu, etm4_dying_cpu); if (ret) goto unregister_notifier; ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "arm/coresight4:online", etm4_online_cpu, NULL); /* HP dyn state ID returned in ret on success */ if (ret > 0) { hp_online = ret; return 0; } /* failed dyn state - remove others */ cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); unregister_notifier: cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); return ret; } static void etm4_pm_clear(void) { cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); if (hp_online) { cpuhp_remove_state_nocalls(hp_online); hp_online = 0; } } static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid) { int ret; struct coresight_platform_data *pdata = NULL; struct etmv4_drvdata *drvdata; struct coresight_desc desc = { 0 }; struct etm4_init_arg init_arg = { 0 }; u8 major, minor; char *type_name; drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); if (!drvdata) return -ENOMEM; dev_set_drvdata(dev, drvdata); if (pm_save_enable == PARAM_PM_SAVE_FIRMWARE) pm_save_enable = coresight_loses_context_with_cpu(dev) ? PARAM_PM_SAVE_SELF_HOSTED : PARAM_PM_SAVE_NEVER; if (pm_save_enable != PARAM_PM_SAVE_NEVER) { drvdata->save_state = devm_kmalloc(dev, sizeof(struct etmv4_save_state), GFP_KERNEL); if (!drvdata->save_state) return -ENOMEM; } drvdata->base = base; spin_lock_init(&drvdata->spinlock); drvdata->cpu = coresight_get_cpu(dev); if (drvdata->cpu < 0) return drvdata->cpu; init_arg.drvdata = drvdata; init_arg.csa = &desc.access; init_arg.pid = etm_pid; if (smp_call_function_single(drvdata->cpu, etm4_init_arch_data, &init_arg, 1)) dev_err(dev, "ETM arch init failed\n"); if (!drvdata->arch) return -EINVAL; /* TRCPDCR is not accessible with system instructions. */ if (!desc.access.io_mem || fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up")) drvdata->skip_power_up = true; major = ETM_ARCH_MAJOR_VERSION(drvdata->arch); minor = ETM_ARCH_MINOR_VERSION(drvdata->arch); if (etm4x_is_ete(drvdata)) { type_name = "ete"; /* ETE v1 has major version == 0b101. Adjust this for logging.*/ major -= 4; } else { type_name = "etm"; } desc.name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", type_name, drvdata->cpu); if (!desc.name) return -ENOMEM; etm4_init_trace_id(drvdata); etm4_set_default(&drvdata->config); pdata = coresight_get_platform_data(dev); if (IS_ERR(pdata)) return PTR_ERR(pdata); dev->platform_data = pdata; desc.type = CORESIGHT_DEV_TYPE_SOURCE; desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC; desc.ops = &etm4_cs_ops; desc.pdata = pdata; desc.dev = dev; desc.groups = coresight_etmv4_groups; drvdata->csdev = coresight_register(&desc); if (IS_ERR(drvdata->csdev)) return PTR_ERR(drvdata->csdev); ret = etm_perf_symlink(drvdata->csdev, true); if (ret) { coresight_unregister(drvdata->csdev); return ret; } /* register with config infrastructure & load any current features */ ret = etm4_cscfg_register(drvdata->csdev); if (ret) { coresight_unregister(drvdata->csdev); return ret; } etmdrvdata[drvdata->cpu] = drvdata; dev_info(&drvdata->csdev->dev, "CPU%d: %s v%d.%d initialized\n", drvdata->cpu, type_name, major, minor); if (boot_enable) { coresight_enable(drvdata->csdev); drvdata->boot_enable = true; } return 0; } static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id) { void __iomem *base; struct device *dev = &adev->dev; struct resource *res = &adev->res; int ret; /* Validity for the resource is already checked by the AMBA core */ base = devm_ioremap_resource(dev, res); if (IS_ERR(base)) return PTR_ERR(base); ret = etm4_probe(dev, base, id->id); if (!ret) pm_runtime_put(&adev->dev); return ret; } static int etm4_probe_platform_dev(struct platform_device *pdev) { int ret; pm_runtime_get_noresume(&pdev->dev); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); /* * System register based devices could match the * HW by reading appropriate registers on the HW * and thus we could skip the PID. */ ret = etm4_probe(&pdev->dev, NULL, 0); pm_runtime_put(&pdev->dev); return ret; } static struct amba_cs_uci_id uci_id_etm4[] = { { /* ETMv4 UCI data */ .devarch = ETM_DEVARCH_ETMv4x_ARCH, .devarch_mask = ETM_DEVARCH_ID_MASK, .devtype = 0x00000013, } }; static void clear_etmdrvdata(void *info) { int cpu = *(int *)info; etmdrvdata[cpu] = NULL; } static int __exit etm4_remove_dev(struct etmv4_drvdata *drvdata) { etm_perf_symlink(drvdata->csdev, false); /* * Taking hotplug lock here to avoid racing between etm4_remove_dev() * and CPU hotplug call backs. */ cpus_read_lock(); /* * The readers for etmdrvdata[] are CPU hotplug call backs * and PM notification call backs. Change etmdrvdata[i] on * CPU i ensures these call backs has consistent view * inside one call back function. */ if (smp_call_function_single(drvdata->cpu, clear_etmdrvdata, &drvdata->cpu, 1)) etmdrvdata[drvdata->cpu] = NULL; cpus_read_unlock(); cscfg_unregister_csdev(drvdata->csdev); coresight_unregister(drvdata->csdev); return 0; } static void __exit etm4_remove_amba(struct amba_device *adev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev); if (drvdata) etm4_remove_dev(drvdata); } static int __exit etm4_remove_platform_dev(struct platform_device *pdev) { int ret = 0; struct etmv4_drvdata *drvdata = dev_get_drvdata(&pdev->dev); if (drvdata) ret = etm4_remove_dev(drvdata); pm_runtime_disable(&pdev->dev); return ret; } static const struct amba_id etm4_ids[] = { CS_AMBA_ID(0x000bb95d), /* Cortex-A53 */ CS_AMBA_ID(0x000bb95e), /* Cortex-A57 */ CS_AMBA_ID(0x000bb95a), /* Cortex-A72 */ CS_AMBA_ID(0x000bb959), /* Cortex-A73 */ CS_AMBA_UCI_ID(0x000bb9da, uci_id_etm4),/* Cortex-A35 */ CS_AMBA_UCI_ID(0x000bbd05, uci_id_etm4),/* Cortex-A55 */ CS_AMBA_UCI_ID(0x000bbd0a, uci_id_etm4),/* Cortex-A75 */ CS_AMBA_UCI_ID(0x000bbd0c, uci_id_etm4),/* Neoverse N1 */ CS_AMBA_UCI_ID(0x000bbd41, uci_id_etm4),/* Cortex-A78 */ CS_AMBA_UCI_ID(0x000f0205, uci_id_etm4),/* Qualcomm Kryo */ CS_AMBA_UCI_ID(0x000f0211, uci_id_etm4),/* Qualcomm Kryo */ CS_AMBA_UCI_ID(0x000bb802, uci_id_etm4),/* Qualcomm Kryo 385 Cortex-A55 */ CS_AMBA_UCI_ID(0x000bb803, uci_id_etm4),/* Qualcomm Kryo 385 Cortex-A75 */ CS_AMBA_UCI_ID(0x000bb805, uci_id_etm4),/* Qualcomm Kryo 4XX Cortex-A55 */ CS_AMBA_UCI_ID(0x000bb804, uci_id_etm4),/* Qualcomm Kryo 4XX Cortex-A76 */ CS_AMBA_UCI_ID(0x000bbd0d, uci_id_etm4),/* Qualcomm Kryo 5XX Cortex-A77 */ CS_AMBA_UCI_ID(0x000cc0af, uci_id_etm4),/* Marvell ThunderX2 */ CS_AMBA_UCI_ID(0x000b6d01, uci_id_etm4),/* HiSilicon-Hip08 */ CS_AMBA_UCI_ID(0x000b6d02, uci_id_etm4),/* HiSilicon-Hip09 */ {}, }; MODULE_DEVICE_TABLE(amba, etm4_ids); static struct amba_driver etm4x_amba_driver = { .drv = { .name = "coresight-etm4x", .owner = THIS_MODULE, .suppress_bind_attrs = true, }, .probe = etm4_probe_amba, .remove = etm4_remove_amba, .id_table = etm4_ids, }; static const struct of_device_id etm4_sysreg_match[] = { { .compatible = "arm,coresight-etm4x-sysreg" }, { .compatible = "arm,embedded-trace-extension" }, {} }; static struct platform_driver etm4_platform_driver = { .probe = etm4_probe_platform_dev, .remove = etm4_remove_platform_dev, .driver = { .name = "coresight-etm4x", .of_match_table = etm4_sysreg_match, .suppress_bind_attrs = true, }, }; static int __init etm4x_init(void) { int ret; ret = etm4_pm_setup(); /* etm4_pm_setup() does its own cleanup - exit on error */ if (ret) return ret; ret = amba_driver_register(&etm4x_amba_driver); if (ret) { pr_err("Error registering etm4x AMBA driver\n"); goto clear_pm; } ret = platform_driver_register(&etm4_platform_driver); if (!ret) return 0; pr_err("Error registering etm4x platform driver\n"); amba_driver_unregister(&etm4x_amba_driver); clear_pm: etm4_pm_clear(); return ret; } static void __exit etm4x_exit(void) { amba_driver_unregister(&etm4x_amba_driver); platform_driver_unregister(&etm4_platform_driver); etm4_pm_clear(); } module_init(etm4x_init); module_exit(etm4x_exit); MODULE_AUTHOR("Pratik Patel "); MODULE_AUTHOR("Mathieu Poirier "); MODULE_DESCRIPTION("Arm CoreSight Program Flow Trace v4.x driver"); MODULE_LICENSE("GPL v2");