diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 77bca6932f01..346c0c37c177 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -42,6 +42,7 @@ #include "coresight-etm4x-cfg.h" #include "coresight-self-hosted-trace.h" #include "coresight-syscfg.h" +#include "coresight-trace-id.h" static int boot_enable; module_param(boot_enable, int, 0444); @@ -237,6 +238,30 @@ static int etm4_trace_id(struct coresight_device *csdev) return drvdata->trcid; } +int etm4_read_alloc_trace_id(struct etmv4_drvdata *drvdata) +{ + int trace_id; + + /* + * This will allocate a trace ID to the cpu, + * or return the one currently allocated. + * The trace id function has its own lock + */ + trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu); + if (IS_VALID_CS_TRACE_ID(trace_id)) + drvdata->trcid = (u8)trace_id; + else + dev_err(&drvdata->csdev->dev, + "Failed to allocate trace ID for %s on CPU%d\n", + dev_name(&drvdata->csdev->dev), drvdata->cpu); + return trace_id; +} + +void etm4_release_trace_id(struct etmv4_drvdata *drvdata) +{ + coresight_trace_id_put_cpu_id(drvdata->cpu); +} + struct etm4_enable_arg { struct etmv4_drvdata *drvdata; int rc; @@ -722,7 +747,7 @@ out: static int etm4_enable_perf(struct coresight_device *csdev, struct perf_event *event) { - int ret = 0; + int ret = 0, trace_id; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) { @@ -734,6 +759,24 @@ static int etm4_enable_perf(struct coresight_device *csdev, ret = etm4_parse_event_config(csdev, event); if (ret) goto out; + + /* + * perf allocates cpu ids as part of _setup_aux() - device needs to use + * the allocated ID. This reads the current version without allocation. + * + * This does not use the trace id lock to prevent lock_dep issues + * with perf locks - we know the ID cannot change until perf shuts down + * the session + */ + trace_id = coresight_trace_id_read_cpu_id(drvdata->cpu); + if (!IS_VALID_CS_TRACE_ID(trace_id)) { + dev_err(&drvdata->csdev->dev, "Failed to set trace ID for %s on CPU%d\n", + dev_name(&drvdata->csdev->dev), drvdata->cpu); + ret = -EINVAL; + goto out; + } + drvdata->trcid = (u8)trace_id; + /* And enable it */ ret = etm4_enable_hw(drvdata); @@ -758,6 +801,11 @@ static int etm4_enable_sysfs(struct coresight_device *csdev) spin_lock(&drvdata->spinlock); + /* sysfs needs to read and allocate a trace ID */ + ret = etm4_read_alloc_trace_id(drvdata); + if (ret < 0) + goto unlock_sysfs_enable; + /* * Executing etm4_enable_hw on the cpu whose ETM is being enabled * ensures that register writes occur when cpu is powered. @@ -769,6 +817,11 @@ static int etm4_enable_sysfs(struct coresight_device *csdev) ret = arg.rc; if (!ret) drvdata->sticky_enable = true; + + if (ret) + etm4_release_trace_id(drvdata); + +unlock_sysfs_enable: spin_unlock(&drvdata->spinlock); if (!ret) @@ -900,6 +953,11 @@ static int etm4_disable_perf(struct coresight_device *csdev, /* TRCVICTLR::SSSTATUS, bit[9] */ filters->ssstatus = (control & BIT(9)); + /* + * perf will release trace ids when _free_aux() is + * called at the end of the session. + */ + return 0; } @@ -925,6 +983,13 @@ static void etm4_disable_sysfs(struct coresight_device *csdev) spin_unlock(&drvdata->spinlock); cpus_read_unlock(); + /* + * we only release trace IDs when resetting sysfs. + * This permits sysfs users to read the trace ID after the trace + * session has completed. This maintains operational behaviour with + * prior trace id allocation method + */ + dev_dbg(&csdev->dev, "ETM tracing disabled\n"); } @@ -1567,11 +1632,6 @@ static int etm4_dying_cpu(unsigned int cpu) 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; @@ -1952,7 +2012,6 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg) if (!desc.name) return -ENOMEM; - etm4_init_trace_id(drvdata); etm4_set_default(&drvdata->config); pdata = coresight_get_platform_data(dev); diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index 9cac848cffaf..5e62aa40ecd0 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -266,10 +266,11 @@ static ssize_t reset_store(struct device *dev, config->vmid_mask0 = 0x0; config->vmid_mask1 = 0x0; - drvdata->trcid = drvdata->cpu + 1; - spin_unlock(&drvdata->spinlock); + /* for sysfs - only release trace id when resetting */ + etm4_release_trace_id(drvdata); + cscfg_csdev_reset_feats(to_coresight_device(dev)); return size; @@ -2392,6 +2393,26 @@ static struct attribute *coresight_etmv4_attrs[] = { NULL, }; +/* + * Trace ID allocated dynamically on enable - but also allocate on read + * in case sysfs or perf read before enable to ensure consistent metadata + * information for trace decode + */ +static ssize_t trctraceid_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int trace_id; + struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); + + trace_id = etm4_read_alloc_trace_id(drvdata); + if (trace_id < 0) + return trace_id; + + return sysfs_emit(buf, "0x%x\n", trace_id); +} +static DEVICE_ATTR_RO(trctraceid); + struct etmv4_reg { struct coresight_device *csdev; u32 offset; @@ -2528,7 +2549,7 @@ static struct attribute *coresight_etmv4_mgmt_attrs[] = { coresight_etm4x_reg(trcpidr3, TRCPIDR3), coresight_etm4x_reg(trcoslsr, TRCOSLSR), coresight_etm4x_reg(trcconfig, TRCCONFIGR), - coresight_etm4x_reg(trctraceid, TRCTRACEIDR), + &dev_attr_trctraceid.attr, coresight_etm4x_reg(trcdevarch, TRCDEVARCH), NULL, }; diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index 4b21bb79f168..434f4e95ee17 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -1095,4 +1095,7 @@ static inline bool etm4x_is_ete(struct etmv4_drvdata *drvdata) { return drvdata->arch >= ETM_ARCH_ETE; } + +int etm4_read_alloc_trace_id(struct etmv4_drvdata *drvdata); +void etm4_release_trace_id(struct etmv4_drvdata *drvdata); #endif