Export an additional common attribute for PMUs that support address range filtering to let the perf userspace identify such PMUs in a uniform way.
Signed-off-by: Alexander Shishkin <[email protected]> --- kernel/events/core.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 606398b62a..6d07e294a7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8282,6 +8282,20 @@ static void free_pmu_context(struct pmu *pmu) out: mutex_unlock(&pmus_lock); } + +/* + * Let userspace know that this PMU supports address range filtering + */ +static ssize_t nr_addr_filters_show(struct device *dev, + struct device_attribute *attr, + char *page) +{ + struct pmu *pmu = dev_get_drvdata(dev); + + return snprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters); +} +DEVICE_ATTR_RO(nr_addr_filters); + static struct idr pmu_idr; static ssize_t @@ -8383,9 +8397,19 @@ static int pmu_dev_alloc(struct pmu *pmu) if (ret) goto free_dev; + /* for PMUs with address filters, throw in an extra attribute */ + if (pmu->nr_addr_filters) + ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters); + + if (ret) + goto del_dev; + out: return ret; +del_dev: + device_del(pmu->dev); + free_dev: put_device(pmu->dev); goto out; @@ -8521,6 +8545,8 @@ void perf_pmu_unregister(struct pmu *pmu) free_percpu(pmu->pmu_disable_count); if (pmu->type >= PERF_TYPE_MAX) idr_remove(&pmu_idr, pmu->type); + if (pmu->nr_addr_filters) + device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); device_del(pmu->dev); put_device(pmu->dev); free_pmu_context(pmu); -- 2.8.0.rc3
