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Date: Thu, 25 Aug 2016 15:19:12 -0600
From: Mathieu Poirier <mathieu.poirier@...aro.org>
To: gregkh@...uxfoundation.org
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 22/28] coresight: etm-perf: configuring filters from perf core
This patch implements the required API needed to access
and retrieve range and start/stop filters from the perf core.
Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
---
drivers/hwtracing/coresight/coresight-etm-perf.c | 149 ++++++++++++++++++++---
drivers/hwtracing/coresight/coresight-etm-perf.h | 34 ++++++
2 files changed, 168 insertions(+), 15 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index e4754e8e6906..98eb207684fa 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -27,6 +27,7 @@
#include <linux/types.h>
#include <linux/workqueue.h>
+#include "coresight-etm-perf.h"
#include "coresight-priv.h"
static struct pmu etm_pmu;
@@ -71,14 +72,48 @@ static const struct attribute_group *etm_pmu_attr_groups[] = {
static void etm_event_read(struct perf_event *event) {}
-static int etm_event_init(struct perf_event *event)
+static int etm_addr_filters_alloc(struct perf_event *event)
{
- if (event->attr.type != etm_pmu.type)
- return -ENOENT;
+ struct etm_filters *filters;
+ int node = event->cpu == -1 ? -1 : cpu_to_node(event->cpu);
+
+ filters = kzalloc_node(sizeof(struct etm_filters), GFP_KERNEL, node);
+ if (!filters)
+ return -ENOMEM;
+
+ if (event->parent)
+ memcpy(filters, event->parent->hw.addr_filters,
+ sizeof(*filters));
+
+ event->hw.addr_filters = filters;
return 0;
}
+static void etm_event_destroy(struct perf_event *event)
+{
+ kfree(event->hw.addr_filters);
+ event->hw.addr_filters = NULL;
+}
+
+static int etm_event_init(struct perf_event *event)
+{
+ int ret = 0;
+
+ if (event->attr.type != etm_pmu.type) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = etm_addr_filters_alloc(event);
+ if (ret)
+ goto out;
+
+ event->destroy = etm_event_destroy;
+out:
+ return ret;
+}
+
static void free_event_data(struct work_struct *work)
{
int cpu;
@@ -342,6 +377,87 @@ static void etm_event_del(struct perf_event *event, int mode)
etm_event_stop(event, PERF_EF_UPDATE);
}
+static int etm_addr_filters_validate(struct list_head *filters)
+{
+ bool range = false, address = false;
+ int index = 0;
+ struct perf_addr_filter *filter;
+
+ list_for_each_entry(filter, filters, entry) {
+ /*
+ * No need to go further if there's no more
+ * room for filters.
+ */
+ if (++index > ETM_ADDR_CMP_MAX)
+ return -EOPNOTSUPP;
+
+ /*
+ * As taken from the struct perf_addr_filter documentation:
+ * @range: 1: range, 0: address
+ *
+ * At this time we don't allow range and start/stop filtering
+ * to cohabitate, they have to be mutually exclusive.
+ */
+ if ((filter->range == 1) && address)
+ return -EOPNOTSUPP;
+
+ if ((filter->range == 0) && range)
+ return -EOPNOTSUPP;
+
+ /*
+ * For range filtering, the second address in the address
+ * range comparator needs to be higher than the first.
+ * Invalid otherwise.
+ */
+ if (filter->range && filter->size == 0)
+ return -EINVAL;
+
+ /*
+ * Everything checks out with this filter, record what we've
+ * received before moving on to the next one.
+ */
+ if (filter->range)
+ range = true;
+ else
+ address = true;
+ }
+
+ return 0;
+}
+
+static void etm_addr_filters_sync(struct perf_event *event)
+{
+ struct perf_addr_filters_head *head = perf_event_addr_filters(event);
+ unsigned long start, stop, *offs = event->addr_filters_offs;
+ struct etm_filters *filters = event->hw.addr_filters;
+ struct etm_filter *etm_filter;
+ struct perf_addr_filter *filter;
+ int i = 0;
+
+ list_for_each_entry(filter, &head->list, entry) {
+ start = filter->offset + offs[i];
+ stop = start + filter->size;
+ etm_filter = &filters->etm_filter[i];
+
+ if (filter->range == 1) {
+ etm_filter->start_addr = start;
+ etm_filter->stop_addr = stop;
+ etm_filter->type = ETM_ADDR_TYPE_RANGE;
+ } else {
+ if (filter->filter == 1) {
+ etm_filter->start_addr = start;
+ etm_filter->type = ETM_ADDR_TYPE_START;
+ } else {
+ etm_filter->stop_addr = stop;
+ etm_filter->type = ETM_ADDR_TYPE_STOP;
+ }
+ }
+ i++;
+ }
+
+ filters->nr_filters = i;
+}
+
int etm_perf_symlink(struct coresight_device *csdev, bool link)
{
char entry[sizeof("cpu9999999")];
@@ -371,18 +487,21 @@ static int __init etm_perf_init(void)
{
int ret;
- etm_pmu.capabilities = PERF_PMU_CAP_EXCLUSIVE;
-
- etm_pmu.attr_groups = etm_pmu_attr_groups;
- etm_pmu.task_ctx_nr = perf_sw_context;
- etm_pmu.read = etm_event_read;
- etm_pmu.event_init = etm_event_init;
- etm_pmu.setup_aux = etm_setup_aux;
- etm_pmu.free_aux = etm_free_aux;
- etm_pmu.start = etm_event_start;
- etm_pmu.stop = etm_event_stop;
- etm_pmu.add = etm_event_add;
- etm_pmu.del = etm_event_del;
+ etm_pmu.capabilities = PERF_PMU_CAP_EXCLUSIVE;
+
+ etm_pmu.attr_groups = etm_pmu_attr_groups;
+ etm_pmu.task_ctx_nr = perf_sw_context;
+ etm_pmu.read = etm_event_read;
+ etm_pmu.event_init = etm_event_init;
+ etm_pmu.setup_aux = etm_setup_aux;
+ etm_pmu.free_aux = etm_free_aux;
+ etm_pmu.start = etm_event_start;
+ etm_pmu.stop = etm_event_stop;
+ etm_pmu.add = etm_event_add;
+ etm_pmu.del = etm_event_del;
+ etm_pmu.addr_filters_sync = etm_addr_filters_sync;
+ etm_pmu.addr_filters_validate = etm_addr_filters_validate;
+ etm_pmu.nr_addr_filters = ETM_ADDR_CMP_MAX;
ret = perf_pmu_register(&etm_pmu, CORESIGHT_ETM_PMU_NAME, -1);
if (ret == 0)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h
index 87f5a134eb6f..3ffc9feb2d64 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.h
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.h
@@ -18,8 +18,42 @@
#ifndef _CORESIGHT_ETM_PERF_H
#define _CORESIGHT_ETM_PERF_H
+#include "coresight-priv.h"
+
struct coresight_device;
+/*
+ * In both ETMv3 and v4 the maximum number of address comparator implentable
+ * is 8. The actual number is implementation specific and will be checked
+ * when filters are applied.
+ */
+#define ETM_ADDR_CMP_MAX 8
+
+/**
+ * struct etm_filter - single instruction range or start/stop configuration.
+ * @start_addr: The address to start tracing on.
+ * @stop_addr: The address to stop tracing on.
+ * @type: Is this a range or start/stop filter.
+ */
+struct etm_filter {
+ unsigned long start_addr;
+ unsigned long stop_addr;
+ enum etm_addr_type type;
+};
+
+/**
+ * struct etm_filters - set of filters for a session
+ * @etm_filter: All the filters for this session.
+ * @nr_filters: Number of filters
+ * @ssstatus: Status of the start/stop logic.
+ */
+struct etm_filters {
+ struct etm_filter etm_filter[ETM_ADDR_CMP_MAX];
+ unsigned int nr_filters;
+ bool ssstatus;
+};
+
+
#ifdef CONFIG_CORESIGHT
int etm_perf_symlink(struct coresight_device *csdev, bool link);
--
2.7.4
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