| Message ID | 20220308205000.27646-6-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: Add new API to allocate trace source ID values | expand |
On Tue, Mar 08, 2022 at 08:49:55PM +0000, Mike Leach wrote: > Use the TraceID API to allocate ETM trace IDs dynamically. > > As with the etm4x we allocate on enable / disable for perf, > allocate on enable / reset for sysfs. > > Additionally we allocate on sysfs file read as both perf and sysfs > can read the ID before enabling the hardware. > > Remove sysfs option to write trace ID - which is inconsistent with > both the dynamic allocation method and the fixed allocation method > previously used. > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > --- > drivers/hwtracing/coresight/coresight-etm.h | 2 + > .../coresight/coresight-etm3x-core.c | 72 ++++++++++++++++--- > .../coresight/coresight-etm3x-sysfs.c | 28 +++----- > 3 files changed, 71 insertions(+), 31 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h > index f3ab96eaf44e..3667428d38b6 100644 > --- a/drivers/hwtracing/coresight/coresight-etm.h > +++ b/drivers/hwtracing/coresight/coresight-etm.h > @@ -287,4 +287,6 @@ int etm_get_trace_id(struct etm_drvdata *drvdata); > void etm_set_default(struct etm_config *config); > void etm_config_trace_mode(struct etm_config *config); > struct etm_config *get_etm_config(struct etm_drvdata *drvdata); > +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata); > +void etm_release_trace_id(struct etm_drvdata *drvdata); > #endif > diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c > index 7d413ba8b823..98213503bd09 100644 > --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c > @@ -32,6 +32,7 @@ > > #include "coresight-etm.h" > #include "coresight-etm-perf.h" > +#include "coresight-trace-id.h" > > /* > * Not really modular but using module_param is the easiest way to > @@ -490,18 +491,57 @@ static int etm_trace_id(struct coresight_device *csdev) > return etm_get_trace_id(drvdata); > } > > +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata) > +{ > + int trace_id; > + > + /* > + * This will allocate a trace ID to the cpu, > + * or return the one currently allocated. > + */ > + trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu, > + coresight_get_trace_id_map()); > + if (trace_id > 0) { > + spin_lock(&drvdata->spinlock); > + drvdata->traceid = (u8)trace_id; > + spin_unlock(&drvdata->spinlock); > + } else { > + pr_err("Failed to allocate trace ID for %s on CPU%d\n", > + dev_name(&drvdata->csdev->dev), drvdata->cpu); > + } > + return trace_id; > +} > + > +void etm_release_trace_id(struct etm_drvdata *drvdata) > +{ > + coresight_trace_id_put_cpu_id(drvdata->cpu, > + coresight_get_trace_id_map()); > + spin_lock(&drvdata->spinlock); > + drvdata->traceid = 0; > + spin_unlock(&drvdata->spinlock); > +} > + > static int etm_enable_perf(struct coresight_device *csdev, > struct perf_event *event) > { > struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); > + int ret; > > if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) > return -EINVAL; > > + ret = etm_read_alloc_trace_id(drvdata); > + if (ret < 0) > + return ret; > For etm4x, this was done after etm_parse_event_config(). Please do the same here. > /* Configure the tracer based on the session's specifics */ > etm_parse_event_config(drvdata, event); > /* And enable it */ > - return etm_enable_hw(drvdata); > + ret = etm_enable_hw(drvdata); > + > + if (ret) > + etm_release_trace_id(drvdata); > + return ret; > } > > static int etm_enable_sysfs(struct coresight_device *csdev) > @@ -510,6 +550,10 @@ static int etm_enable_sysfs(struct coresight_device *csdev) > struct etm_enable_arg arg = { }; > int ret; > > + ret = etm_read_alloc_trace_id(drvdata); > + if (ret < 0) > + return ret; > + Please add the same comment as in etm4_disable_sysfs() in etm_disable_sysfs(). > spin_lock(&drvdata->spinlock); > > /* > @@ -532,6 +576,8 @@ static int etm_enable_sysfs(struct coresight_device *csdev) > > if (!ret) > dev_dbg(&csdev->dev, "ETM tracing enabled\n"); > + else > + etm_release_trace_id(drvdata); > return ret; > } > > @@ -611,6 +657,8 @@ static void etm_disable_perf(struct coresight_device *csdev) > coresight_disclaim_device_unlocked(csdev); > > CS_LOCK(drvdata->base); > + > + etm_release_trace_id(drvdata); > } > > static void etm_disable_sysfs(struct coresight_device *csdev) > @@ -781,11 +829,6 @@ static void etm_init_arch_data(void *info) > CS_LOCK(drvdata->base); > } > > -static void etm_init_trace_id(struct etm_drvdata *drvdata) > -{ > - drvdata->traceid = coresight_get_trace_id(drvdata->cpu); > -} > - > static int __init etm_hp_setup(void) > { > int ret; > @@ -871,7 +914,6 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) > if (etm_arch_supported(drvdata->arch) == false) > return -EINVAL; > > - etm_init_trace_id(drvdata); > etm_set_default(&drvdata->config); > > pdata = coresight_get_platform_data(dev); > @@ -891,10 +933,12 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) > return PTR_ERR(drvdata->csdev); > > ret = etm_perf_symlink(drvdata->csdev, true); > - if (ret) { > - coresight_unregister(drvdata->csdev); > - return ret; > - } > + if (ret) > + goto cs_unregister; > + > + ret = etm_read_alloc_trace_id(drvdata); > + if (ret < 0) > + goto cs_unregister; > > etmdrvdata[drvdata->cpu] = drvdata; > > @@ -907,6 +951,10 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) > } > > return 0; > + > +cs_unregister: > + coresight_unregister(drvdata->csdev); > + return ret; > } > > static void clear_etmdrvdata(void *info) > @@ -922,6 +970,8 @@ static void etm_remove(struct amba_device *adev) > > etm_perf_symlink(drvdata->csdev, false); > > + etm_release_trace_id(drvdata); > + > /* > * Taking hotplug lock here to avoid racing between etm_remove and > * CPU hotplug call backs. > diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > index e8c7649f123e..3ee70b174240 100644 > --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > @@ -86,6 +86,8 @@ static ssize_t reset_store(struct device *dev, > > etm_set_default(config); > spin_unlock(&drvdata->spinlock); > + /* release trace id outside the spinlock as this fn uses it */ > + etm_release_trace_id(drvdata); > } > > return size; > @@ -1189,30 +1191,16 @@ static DEVICE_ATTR_RO(cpu); > static ssize_t traceid_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > - unsigned long val; > - struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); > - > - val = etm_get_trace_id(drvdata); > - > - return sprintf(buf, "%#lx\n", val); > -} > - > -static ssize_t traceid_store(struct device *dev, > - struct device_attribute *attr, > - const char *buf, size_t size) > -{ > - int ret; > - unsigned long val; > + int trace_id; > struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); > > - ret = kstrtoul(buf, 16, &val); > - if (ret) > - return ret; > + trace_id = etm_read_alloc_trace_id(drvdata); > + if (trace_id < 0) > + return trace_id; > > - drvdata->traceid = val & ETM_TRACEID_MASK; > - return size; > + return sprintf(buf, "%#x\n", trace_id); > } > -static DEVICE_ATTR_RW(traceid); > +static DEVICE_ATTR_RO(traceid); > > static struct attribute *coresight_etm_attrs[] = { > &dev_attr_nr_addr_cmp.attr, > -- > 2.17.1 >
Hii On Tue, 5 Apr 2022 at 18:22, Mathieu Poirier <mathieu.poirier@linaro.org> wrote: > > On Tue, Mar 08, 2022 at 08:49:55PM +0000, Mike Leach wrote: > > Use the TraceID API to allocate ETM trace IDs dynamically. > > > > As with the etm4x we allocate on enable / disable for perf, > > allocate on enable / reset for sysfs. > > > > Additionally we allocate on sysfs file read as both perf and sysfs > > can read the ID before enabling the hardware. > > > > Remove sysfs option to write trace ID - which is inconsistent with > > both the dynamic allocation method and the fixed allocation method > > previously used. > > > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > > --- > > drivers/hwtracing/coresight/coresight-etm.h | 2 + > > .../coresight/coresight-etm3x-core.c | 72 ++++++++++++++++--- > > .../coresight/coresight-etm3x-sysfs.c | 28 +++----- > > 3 files changed, 71 insertions(+), 31 deletions(-) > > > > diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h > > index f3ab96eaf44e..3667428d38b6 100644 > > --- a/drivers/hwtracing/coresight/coresight-etm.h > > +++ b/drivers/hwtracing/coresight/coresight-etm.h > > @@ -287,4 +287,6 @@ int etm_get_trace_id(struct etm_drvdata *drvdata); > > void etm_set_default(struct etm_config *config); > > void etm_config_trace_mode(struct etm_config *config); > > struct etm_config *get_etm_config(struct etm_drvdata *drvdata); > > +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata); > > +void etm_release_trace_id(struct etm_drvdata *drvdata); > > #endif > > diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c > > index 7d413ba8b823..98213503bd09 100644 > > --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c > > +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c > > @@ -32,6 +32,7 @@ > > > > #include "coresight-etm.h" > > #include "coresight-etm-perf.h" > > +#include "coresight-trace-id.h" > > > > /* > > * Not really modular but using module_param is the easiest way to > > @@ -490,18 +491,57 @@ static int etm_trace_id(struct coresight_device *csdev) > > return etm_get_trace_id(drvdata); > > } > > > > +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata) > > +{ > > + int trace_id; > > + > > + /* > > + * This will allocate a trace ID to the cpu, > > + * or return the one currently allocated. > > + */ > > + trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu, > > + coresight_get_trace_id_map()); > > + if (trace_id > 0) { > > + spin_lock(&drvdata->spinlock); > > + drvdata->traceid = (u8)trace_id; > > + spin_unlock(&drvdata->spinlock); > > + } else { > > + pr_err("Failed to allocate trace ID for %s on CPU%d\n", > > + dev_name(&drvdata->csdev->dev), drvdata->cpu); > > + } > > + return trace_id; > > +} > > + > > +void etm_release_trace_id(struct etm_drvdata *drvdata) > > +{ > > + coresight_trace_id_put_cpu_id(drvdata->cpu, > > + coresight_get_trace_id_map()); > > + spin_lock(&drvdata->spinlock); > > + drvdata->traceid = 0; > > + spin_unlock(&drvdata->spinlock); > > +} > > + > > static int etm_enable_perf(struct coresight_device *csdev, > > struct perf_event *event) > > { > > struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); > > + int ret; > > > > if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) > > return -EINVAL; > > > > + ret = etm_read_alloc_trace_id(drvdata); > > + if (ret < 0) > > + return ret; > > > > For etm4x, this was done after etm_parse_event_config(). Please do the same > here. > > > > /* Configure the tracer based on the session's specifics */ > > etm_parse_event_config(drvdata, event); > > /* And enable it */ > > - return etm_enable_hw(drvdata); > > + ret = etm_enable_hw(drvdata); > > + > > + if (ret) > > + etm_release_trace_id(drvdata); > > + return ret; > > } > > > > static int etm_enable_sysfs(struct coresight_device *csdev) > > @@ -510,6 +550,10 @@ static int etm_enable_sysfs(struct coresight_device *csdev) > > struct etm_enable_arg arg = { }; > > int ret; > > > > + ret = etm_read_alloc_trace_id(drvdata); > > + if (ret < 0) > > + return ret; > > + > > Please add the same comment as in etm4_disable_sysfs() in etm_disable_sysfs(). > Agreed for both comments on this patch Thanks Mike > > spin_lock(&drvdata->spinlock); > > > > /* > > @@ -532,6 +576,8 @@ static int etm_enable_sysfs(struct coresight_device *csdev) > > > > if (!ret) > > dev_dbg(&csdev->dev, "ETM tracing enabled\n"); > > + else > > + etm_release_trace_id(drvdata); > > return ret; > > } > > > > @@ -611,6 +657,8 @@ static void etm_disable_perf(struct coresight_device *csdev) > > coresight_disclaim_device_unlocked(csdev); > > > > CS_LOCK(drvdata->base); > > + > > + etm_release_trace_id(drvdata); > > } > > > > static void etm_disable_sysfs(struct coresight_device *csdev) > > @@ -781,11 +829,6 @@ static void etm_init_arch_data(void *info) > > CS_LOCK(drvdata->base); > > } > > > > -static void etm_init_trace_id(struct etm_drvdata *drvdata) > > -{ > > - drvdata->traceid = coresight_get_trace_id(drvdata->cpu); > > -} > > - > > static int __init etm_hp_setup(void) > > { > > int ret; > > @@ -871,7 +914,6 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) > > if (etm_arch_supported(drvdata->arch) == false) > > return -EINVAL; > > > > - etm_init_trace_id(drvdata); > > etm_set_default(&drvdata->config); > > > > pdata = coresight_get_platform_data(dev); > > @@ -891,10 +933,12 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) > > return PTR_ERR(drvdata->csdev); > > > > ret = etm_perf_symlink(drvdata->csdev, true); > > - if (ret) { > > - coresight_unregister(drvdata->csdev); > > - return ret; > > - } > > + if (ret) > > + goto cs_unregister; > > + > > + ret = etm_read_alloc_trace_id(drvdata); > > + if (ret < 0) > > + goto cs_unregister; > > > > etmdrvdata[drvdata->cpu] = drvdata; > > > > @@ -907,6 +951,10 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) > > } > > > > return 0; > > + > > +cs_unregister: > > + coresight_unregister(drvdata->csdev); > > + return ret; > > } > > > > static void clear_etmdrvdata(void *info) > > @@ -922,6 +970,8 @@ static void etm_remove(struct amba_device *adev) > > > > etm_perf_symlink(drvdata->csdev, false); > > > > + etm_release_trace_id(drvdata); > > + > > /* > > * Taking hotplug lock here to avoid racing between etm_remove and > > * CPU hotplug call backs. > > diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > > index e8c7649f123e..3ee70b174240 100644 > > --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > > +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > > @@ -86,6 +86,8 @@ static ssize_t reset_store(struct device *dev, > > > > etm_set_default(config); > > spin_unlock(&drvdata->spinlock); > > + /* release trace id outside the spinlock as this fn uses it */ > > + etm_release_trace_id(drvdata); > > } > > > > return size; > > @@ -1189,30 +1191,16 @@ static DEVICE_ATTR_RO(cpu); > > static ssize_t traceid_show(struct device *dev, > > struct device_attribute *attr, char *buf) > > { > > - unsigned long val; > > - struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); > > - > > - val = etm_get_trace_id(drvdata); > > - > > - return sprintf(buf, "%#lx\n", val); > > -} > > - > > -static ssize_t traceid_store(struct device *dev, > > - struct device_attribute *attr, > > - const char *buf, size_t size) > > -{ > > - int ret; > > - unsigned long val; > > + int trace_id; > > struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); > > > > - ret = kstrtoul(buf, 16, &val); > > - if (ret) > > - return ret; > > + trace_id = etm_read_alloc_trace_id(drvdata); > > + if (trace_id < 0) > > + return trace_id; > > > > - drvdata->traceid = val & ETM_TRACEID_MASK; > > - return size; > > + return sprintf(buf, "%#x\n", trace_id); > > } > > -static DEVICE_ATTR_RW(traceid); > > +static DEVICE_ATTR_RO(traceid); > > > > static struct attribute *coresight_etm_attrs[] = { > > &dev_attr_nr_addr_cmp.attr, > > -- > > 2.17.1 > >
diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h index f3ab96eaf44e..3667428d38b6 100644 --- a/drivers/hwtracing/coresight/coresight-etm.h +++ b/drivers/hwtracing/coresight/coresight-etm.h @@ -287,4 +287,6 @@ int etm_get_trace_id(struct etm_drvdata *drvdata); void etm_set_default(struct etm_config *config); void etm_config_trace_mode(struct etm_config *config); struct etm_config *get_etm_config(struct etm_drvdata *drvdata); +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata); +void etm_release_trace_id(struct etm_drvdata *drvdata); #endif diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c index 7d413ba8b823..98213503bd09 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -32,6 +32,7 @@ #include "coresight-etm.h" #include "coresight-etm-perf.h" +#include "coresight-trace-id.h" /* * Not really modular but using module_param is the easiest way to @@ -490,18 +491,57 @@ static int etm_trace_id(struct coresight_device *csdev) return etm_get_trace_id(drvdata); } +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata) +{ + int trace_id; + + /* + * This will allocate a trace ID to the cpu, + * or return the one currently allocated. + */ + trace_id = coresight_trace_id_get_cpu_id(drvdata->cpu, + coresight_get_trace_id_map()); + if (trace_id > 0) { + spin_lock(&drvdata->spinlock); + drvdata->traceid = (u8)trace_id; + spin_unlock(&drvdata->spinlock); + } else { + pr_err("Failed to allocate trace ID for %s on CPU%d\n", + dev_name(&drvdata->csdev->dev), drvdata->cpu); + } + return trace_id; +} + +void etm_release_trace_id(struct etm_drvdata *drvdata) +{ + coresight_trace_id_put_cpu_id(drvdata->cpu, + coresight_get_trace_id_map()); + spin_lock(&drvdata->spinlock); + drvdata->traceid = 0; + spin_unlock(&drvdata->spinlock); +} + static int etm_enable_perf(struct coresight_device *csdev, struct perf_event *event) { struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + int ret; if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id())) return -EINVAL; + ret = etm_read_alloc_trace_id(drvdata); + if (ret < 0) + return ret; + /* Configure the tracer based on the session's specifics */ etm_parse_event_config(drvdata, event); /* And enable it */ - return etm_enable_hw(drvdata); + ret = etm_enable_hw(drvdata); + + if (ret) + etm_release_trace_id(drvdata); + return ret; } static int etm_enable_sysfs(struct coresight_device *csdev) @@ -510,6 +550,10 @@ static int etm_enable_sysfs(struct coresight_device *csdev) struct etm_enable_arg arg = { }; int ret; + ret = etm_read_alloc_trace_id(drvdata); + if (ret < 0) + return ret; + spin_lock(&drvdata->spinlock); /* @@ -532,6 +576,8 @@ static int etm_enable_sysfs(struct coresight_device *csdev) if (!ret) dev_dbg(&csdev->dev, "ETM tracing enabled\n"); + else + etm_release_trace_id(drvdata); return ret; } @@ -611,6 +657,8 @@ static void etm_disable_perf(struct coresight_device *csdev) coresight_disclaim_device_unlocked(csdev); CS_LOCK(drvdata->base); + + etm_release_trace_id(drvdata); } static void etm_disable_sysfs(struct coresight_device *csdev) @@ -781,11 +829,6 @@ static void etm_init_arch_data(void *info) CS_LOCK(drvdata->base); } -static void etm_init_trace_id(struct etm_drvdata *drvdata) -{ - drvdata->traceid = coresight_get_trace_id(drvdata->cpu); -} - static int __init etm_hp_setup(void) { int ret; @@ -871,7 +914,6 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) if (etm_arch_supported(drvdata->arch) == false) return -EINVAL; - etm_init_trace_id(drvdata); etm_set_default(&drvdata->config); pdata = coresight_get_platform_data(dev); @@ -891,10 +933,12 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) return PTR_ERR(drvdata->csdev); ret = etm_perf_symlink(drvdata->csdev, true); - if (ret) { - coresight_unregister(drvdata->csdev); - return ret; - } + if (ret) + goto cs_unregister; + + ret = etm_read_alloc_trace_id(drvdata); + if (ret < 0) + goto cs_unregister; etmdrvdata[drvdata->cpu] = drvdata; @@ -907,6 +951,10 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) } return 0; + +cs_unregister: + coresight_unregister(drvdata->csdev); + return ret; } static void clear_etmdrvdata(void *info) @@ -922,6 +970,8 @@ static void etm_remove(struct amba_device *adev) etm_perf_symlink(drvdata->csdev, false); + etm_release_trace_id(drvdata); + /* * Taking hotplug lock here to avoid racing between etm_remove and * CPU hotplug call backs. diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c index e8c7649f123e..3ee70b174240 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c @@ -86,6 +86,8 @@ static ssize_t reset_store(struct device *dev, etm_set_default(config); spin_unlock(&drvdata->spinlock); + /* release trace id outside the spinlock as this fn uses it */ + etm_release_trace_id(drvdata); } return size; @@ -1189,30 +1191,16 @@ static DEVICE_ATTR_RO(cpu); static ssize_t traceid_show(struct device *dev, struct device_attribute *attr, char *buf) { - unsigned long val; - struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); - - val = etm_get_trace_id(drvdata); - - return sprintf(buf, "%#lx\n", val); -} - -static ssize_t traceid_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t size) -{ - int ret; - unsigned long val; + int trace_id; struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); - ret = kstrtoul(buf, 16, &val); - if (ret) - return ret; + trace_id = etm_read_alloc_trace_id(drvdata); + if (trace_id < 0) + return trace_id; - drvdata->traceid = val & ETM_TRACEID_MASK; - return size; + return sprintf(buf, "%#x\n", trace_id); } -static DEVICE_ATTR_RW(traceid); +static DEVICE_ATTR_RO(traceid); static struct attribute *coresight_etm_attrs[] = { &dev_attr_nr_addr_cmp.attr,
Use the TraceID API to allocate ETM trace IDs dynamically. As with the etm4x we allocate on enable / disable for perf, allocate on enable / reset for sysfs. Additionally we allocate on sysfs file read as both perf and sysfs can read the ID before enabling the hardware. Remove sysfs option to write trace ID - which is inconsistent with both the dynamic allocation method and the fixed allocation method previously used. Signed-off-by: Mike Leach <mike.leach@linaro.org> --- drivers/hwtracing/coresight/coresight-etm.h | 2 + .../coresight/coresight-etm3x-core.c | 72 ++++++++++++++++--- .../coresight/coresight-etm3x-sysfs.c | 28 +++----- 3 files changed, 71 insertions(+), 31 deletions(-)