diff mbox

[03/10] coresight: etm-perf: configuring filters from perf core

Message ID 1468871491-10997-4-git-send-email-mathieu.poirier@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Mathieu Poirier July 18, 2016, 7:51 p.m. UTC
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@linaro.org>
---
 drivers/hwtracing/coresight/coresight-etm-perf.c | 146 ++++++++++++++++++++---
 drivers/hwtracing/coresight/coresight-etm-perf.h |  32 +++++
 2 files changed, 162 insertions(+), 16 deletions(-)

Comments

Suzuki K Poulose July 20, 2016, 4:07 p.m. UTC | #1
On 18/07/16 20:51, Mathieu Poirier wrote:
> 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@linaro.org>
> ---
>  drivers/hwtracing/coresight/coresight-etm-perf.c | 146 ++++++++++++++++++++---
>  drivers/hwtracing/coresight/coresight-etm-perf.h |  32 +++++
>  2 files changed, 162 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index 78a1bc0013a2..fde7f42149c5 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -29,6 +29,7 @@
>  #include <linux/workqueue.h>
>
>  #include "coresight-priv.h"
> +#include "coresight-etm-perf.h"
>
>  static struct pmu etm_pmu;
>  static bool etm_perf_up;
> @@ -83,12 +84,44 @@ static const struct attribute_group *etm_pmu_attr_groups[] = {
>
>  static void etm_event_read(struct perf_event *event) {}
>
> +static int etm_addr_filters_alloc(struct perf_event *event)
> +{

...

> +	return 0;
> +}
> +


> +
>  static int etm_event_init(struct perf_event *event)
>  {
> +	int ret;
> +
>  	if (event->attr.type != etm_pmu.type)
>  		return -ENOENT;
>
> -	return 0;
> +	ret = etm_addr_filters_alloc(event);


>  }
>
>  static void free_event_data(struct work_struct *work)
> @@ -456,6 +489,85 @@ static void etm_free_drv_configs(struct perf_event *event)
>  	}
>  }
>
> +static int etm_addr_filters_validate(struct list_head *filters)
> +{

> +
> +	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 perf_addr_filter *filter;
> +	int i = 0;

Is it possible to delay the etm_addr_filters_alloc() until this point ?
I understand that this function cannot report back failures if we fail
to allocate memory. Or may be do a lazy allocation from addr_filters_validate(),
when we get the first filter added.

Of course this could be done as a follow up patch to improve things once
we get the initial framework in.



> +
> +	list_for_each_entry(filter, &head->list, entry) {
> +		start = filter->offset + offs[i];
> +		stop = start + filter->size;
> +
> +		if (filter->range == 1) {
> +			filters->filter[i].start_addr = start;
> +			filters->filter[i].stop_addr = stop;
> +			filters->filter[i].type = ETM_ADDR_TYPE_RANGE;
> +		} else {
> +			if (filter->filter == 1) {
> +				filters->filter[i].start_addr = start;
> +				filters->filter[i].type = ETM_ADDR_TYPE_START;
> +			} else {
> +				filters->filter[i].stop_addr = stop;
> +				filters->filter[i].type = ETM_ADDR_TYPE_STOP;
> +			}
> +		}
> +		i++;
> +	}
> +
> +	filters->nr_filters = i;
> +/**
> + * 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	filter[ETM_ADDR_CMP_MAX];

nit: having the variable renamed to etm_filter will make the code a bit more readable
where we populate/validate the filters.

Otherwise looks good

Suzuki
Mathieu Poirier July 21, 2016, 3:15 p.m. UTC | #2
On 20 July 2016 at 10:07, Suzuki K Poulose <Suzuki.Poulose@arm.com> wrote:
> On 18/07/16 20:51, Mathieu Poirier wrote:
>>
>> 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@linaro.org>
>> ---
>>  drivers/hwtracing/coresight/coresight-etm-perf.c | 146
>> ++++++++++++++++++++---
>>  drivers/hwtracing/coresight/coresight-etm-perf.h |  32 +++++
>>  2 files changed, 162 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c
>> b/drivers/hwtracing/coresight/coresight-etm-perf.c
>> index 78a1bc0013a2..fde7f42149c5 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
>> @@ -29,6 +29,7 @@
>>  #include <linux/workqueue.h>
>>
>>  #include "coresight-priv.h"
>> +#include "coresight-etm-perf.h"
>>
>>  static struct pmu etm_pmu;
>>  static bool etm_perf_up;
>> @@ -83,12 +84,44 @@ static const struct attribute_group
>> *etm_pmu_attr_groups[] = {
>>
>>  static void etm_event_read(struct perf_event *event) {}
>>
>> +static int etm_addr_filters_alloc(struct perf_event *event)
>> +{
>
>
> ...
>
>> +       return 0;
>> +}
>> +
>
>
>
>> +
>>  static int etm_event_init(struct perf_event *event)
>>  {
>> +       int ret;
>> +
>>         if (event->attr.type != etm_pmu.type)
>>                 return -ENOENT;
>>
>> -       return 0;
>> +       ret = etm_addr_filters_alloc(event);
>
>
>
>>  }
>>
>>  static void free_event_data(struct work_struct *work)
>> @@ -456,6 +489,85 @@ static void etm_free_drv_configs(struct perf_event
>> *event)
>>         }
>>  }
>>
>> +static int etm_addr_filters_validate(struct list_head *filters)
>> +{
>
>
>> +
>> +       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 perf_addr_filter *filter;
>> +       int i = 0;
>
>
> Is it possible to delay the etm_addr_filters_alloc() until this point ?
> I understand that this function cannot report back failures if we fail
> to allocate memory. Or may be do a lazy allocation from
> addr_filters_validate(),
> when we get the first filter added.

Humm... You want to avoid allocating memory that may never be used if
filters aren't specified.  Ok, let's do the allocation in
addr_filters_validate().

>
> Of course this could be done as a follow up patch to improve things once
> we get the initial framework in.
>
>
>
>> +
>> +       list_for_each_entry(filter, &head->list, entry) {
>> +               start = filter->offset + offs[i];
>> +               stop = start + filter->size;
>> +
>> +               if (filter->range == 1) {
>> +                       filters->filter[i].start_addr = start;
>> +                       filters->filter[i].stop_addr = stop;
>> +                       filters->filter[i].type = ETM_ADDR_TYPE_RANGE;
>> +               } else {
>> +                       if (filter->filter == 1) {
>> +                               filters->filter[i].start_addr = start;
>> +                               filters->filter[i].type =
>> ETM_ADDR_TYPE_START;
>> +                       } else {
>> +                               filters->filter[i].stop_addr = stop;
>> +                               filters->filter[i].type =
>> ETM_ADDR_TYPE_STOP;
>> +                       }
>> +               }
>> +               i++;
>> +       }
>> +
>> +       filters->nr_filters = i;
>> +/**
>> + * 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       filter[ETM_ADDR_CMP_MAX];
>
>
> nit: having the variable renamed to etm_filter will make the code a bit more
> readable
> where we populate/validate the filters.

Very well.

Thanks,
Mathieu

>
> Otherwise looks good
>
> Suzuki
Mathieu Poirier July 21, 2016, 5:12 p.m. UTC | #3
On 21 July 2016 at 09:15, Mathieu Poirier <mathieu.poirier@linaro.org> wrote:
> On 20 July 2016 at 10:07, Suzuki K Poulose <Suzuki.Poulose@arm.com> wrote:
>> On 18/07/16 20:51, Mathieu Poirier wrote:
>>>
>>> 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@linaro.org>
>>> ---
>>>  drivers/hwtracing/coresight/coresight-etm-perf.c | 146
>>> ++++++++++++++++++++---
>>>  drivers/hwtracing/coresight/coresight-etm-perf.h |  32 +++++
>>>  2 files changed, 162 insertions(+), 16 deletions(-)
>>>
>>> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c
>>> b/drivers/hwtracing/coresight/coresight-etm-perf.c
>>> index 78a1bc0013a2..fde7f42149c5 100644
>>> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
>>> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
>>> @@ -29,6 +29,7 @@
>>>  #include <linux/workqueue.h>
>>>
>>>  #include "coresight-priv.h"
>>> +#include "coresight-etm-perf.h"
>>>
>>>  static struct pmu etm_pmu;
>>>  static bool etm_perf_up;
>>> @@ -83,12 +84,44 @@ static const struct attribute_group
>>> *etm_pmu_attr_groups[] = {
>>>
>>>  static void etm_event_read(struct perf_event *event) {}
>>>
>>> +static int etm_addr_filters_alloc(struct perf_event *event)
>>> +{
>>
>>
>> ...
>>
>>> +       return 0;
>>> +}
>>> +
>>
>>
>>
>>> +
>>>  static int etm_event_init(struct perf_event *event)
>>>  {
>>> +       int ret;
>>> +
>>>         if (event->attr.type != etm_pmu.type)
>>>                 return -ENOENT;
>>>
>>> -       return 0;
>>> +       ret = etm_addr_filters_alloc(event);
>>
>>
>>
>>>  }
>>>
>>>  static void free_event_data(struct work_struct *work)
>>> @@ -456,6 +489,85 @@ static void etm_free_drv_configs(struct perf_event
>>> *event)
>>>         }
>>>  }
>>>
>>> +static int etm_addr_filters_validate(struct list_head *filters)
>>> +{
>>
>>
>>> +
>>> +       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 perf_addr_filter *filter;
>>> +       int i = 0;
>>
>>
>> Is it possible to delay the etm_addr_filters_alloc() until this point ?
>> I understand that this function cannot report back failures if we fail
>> to allocate memory. Or may be do a lazy allocation from
>> addr_filters_validate(),
>> when we get the first filter added.
>
> Humm... You want to avoid allocating memory that may never be used if
> filters aren't specified.  Ok, let's do the allocation in
> addr_filters_validate().
>

On second thought we don't have access to the perf event in
addr_filters_validate() so the previous strategy won't work.  And as
you said etm_addr_filters_sync() doesn't return an error code so that
won't work either.  As such I will keep the current code as is.

Mathieu

>>
>> Of course this could be done as a follow up patch to improve things once
>> we get the initial framework in.
>>
>>
>>
>>> +
>>> +       list_for_each_entry(filter, &head->list, entry) {
>>> +               start = filter->offset + offs[i];
>>> +               stop = start + filter->size;
>>> +
>>> +               if (filter->range == 1) {
>>> +                       filters->filter[i].start_addr = start;
>>> +                       filters->filter[i].stop_addr = stop;
>>> +                       filters->filter[i].type = ETM_ADDR_TYPE_RANGE;
>>> +               } else {
>>> +                       if (filter->filter == 1) {
>>> +                               filters->filter[i].start_addr = start;
>>> +                               filters->filter[i].type =
>>> ETM_ADDR_TYPE_START;
>>> +                       } else {
>>> +                               filters->filter[i].stop_addr = stop;
>>> +                               filters->filter[i].type =
>>> ETM_ADDR_TYPE_STOP;
>>> +                       }
>>> +               }
>>> +               i++;
>>> +       }
>>> +
>>> +       filters->nr_filters = i;
>>> +/**
>>> + * 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       filter[ETM_ADDR_CMP_MAX];
>>
>>
>> nit: having the variable renamed to etm_filter will make the code a bit more
>> readable
>> where we populate/validate the filters.
>
> Very well.
>
> Thanks,
> Mathieu
>
>>
>> Otherwise looks good
>>
>> Suzuki
diff mbox

Patch

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 78a1bc0013a2..fde7f42149c5 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -29,6 +29,7 @@ 
 #include <linux/workqueue.h>
 
 #include "coresight-priv.h"
+#include "coresight-etm-perf.h"
 
 static struct pmu etm_pmu;
 static bool etm_perf_up;
@@ -83,12 +84,44 @@  static const struct attribute_group *etm_pmu_attr_groups[] = {
 
 static void etm_event_read(struct perf_event *event) {}
 
+static int etm_addr_filters_alloc(struct perf_event *event)
+{
+	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;
+
 	if (event->attr.type != etm_pmu.type)
 		return -ENOENT;
 
-	return 0;
+	ret = etm_addr_filters_alloc(event);
+	if (ret)
+		return ret;
+
+	event->destroy = etm_event_destroy;
+
+	return ret;
 }
 
 static void free_event_data(struct work_struct *work)
@@ -456,6 +489,85 @@  static void etm_free_drv_configs(struct perf_event *event)
 	}
 }
 
+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 perf_addr_filter *filter;
+	int i = 0;
+
+	list_for_each_entry(filter, &head->list, entry) {
+		start = filter->offset + offs[i];
+		stop = start + filter->size;
+
+		if (filter->range == 1) {
+			filters->filter[i].start_addr = start;
+			filters->filter[i].stop_addr = stop;
+			filters->filter[i].type = ETM_ADDR_TYPE_RANGE;
+		} else {
+			if (filter->filter == 1) {
+				filters->filter[i].start_addr = start;
+				filters->filter[i].type = ETM_ADDR_TYPE_START;
+			} else {
+				filters->filter[i].stop_addr = stop;
+				filters->filter[i].type = ETM_ADDR_TYPE_STOP;
+			}
+		}
+		i++;
+	}
+
+	filters->nr_filters = i;
+}
+
 int etm_perf_symlink(struct coresight_device *csdev, bool link)
 {
 	char entry[sizeof("cpu9999999")];
@@ -485,21 +597,23 @@  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.get_drv_configs	= etm_get_drv_configs;
-	etm_pmu.free_drv_configs
-				= etm_free_drv_configs;
+	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.get_drv_configs		= etm_get_drv_configs;
+	etm_pmu.free_drv_configs	= etm_free_drv_configs;
+	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..28be38a9be60 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.h
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.h
@@ -20,6 +20,38 @@ 
 
 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	filter[ETM_ADDR_CMP_MAX];
+	unsigned int		nr_filters;
+	bool			ssstatus;
+};
+
+
 #ifdef CONFIG_CORESIGHT
 int etm_perf_symlink(struct coresight_device *csdev, bool link);