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coresight: perf: Add "sinks" group to PMU directory
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Add a "sinks" directory entry so that users can see all the sinks
available in the system in a single place.  Individual sink are added
as they are registered with the coresight bus.

Committer tests:

Test built on a ubuntu 18.04 container with a cross build environment to
arm64, the new field is there, need to find a machine with this feature
to do further testing in the future.

  root@d15263e5734a:/git/perf# grep CORESIGHT /tmp/build/v5.0-rc2+/.config
  CONFIG_CORESIGHT=y
  CONFIG_CORESIGHT_LINKS_AND_SINKS=y
  CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y
  CONFIG_CORESIGHT_CATU=y
  CONFIG_CORESIGHT_SINK_TPIU=y
  CONFIG_CORESIGHT_SINK_ETBV10=y
  CONFIG_CORESIGHT_SOURCE_ETM4X=y
  CONFIG_CORESIGHT_DYNAMIC_REPLICATOR=y
  CONFIG_CORESIGHT_STM=y
  CONFIG_CORESIGHT_CPU_DEBUG=m
  root@d15263e5734a:/git/perf#
  root@d15263e5734a:/git/perf# file /tmp/build/v5.0-rc2+/drivers/hwtracing/coresight/*.o
  .../coresight/coresight-catu.o:               ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-cpu-debug.mod.o:      ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-cpu-debug.o:          ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-dynamic-replicator.o: ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-etb10.o:              ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-etm-perf.o:           ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-etm4x-sysfs.o:        ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-etm4x.o:              ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-funnel.o:             ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-replicator.o:         ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-stm.o:                ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-tmc-etf.o:            ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-tmc-etr.o:            ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-tmc.o:                ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight-tpiu.o:               ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/coresight.o:                    ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  .../coresight/of_coresight.o:                 ELF 64-bit MSB relocatable, ARM aarch64, version 1 (SYSV), not stripped
  root@d15263e5734a:/git/perf#

  root@d15263e5734a:/git/perf# pahole -C coresight_device /tmp/build/v5.0-rc2+/drivers/hwtracing/coresight/coresight.o
  struct coresight_device {
          struct coresight_connection * conns;             /*     0     8 */
          int                        nr_inport;            /*     8     4 */
          int                        nr_outport;           /*    12     4 */
          enum coresight_dev_type    type;                 /*    16     4 */
          union coresight_dev_subtype subtype;             /*    20     8 */

          /* XXX 4 bytes hole, try to pack */

          const struct coresight_ops  * ops;               /*    32     8 */
          struct device              dev;                  /*    40  1408 */

          /* XXX last struct has 7 bytes of padding */

          /* --- cacheline 22 boundary (1408 bytes) was 40 bytes ago --- */
          atomic_t *                 refcnt;               /*  1448     8 */
          bool                       orphan;               /*  1456     1 */
          bool                       enable;               /*  1457     1 */
          bool                       activated;            /*  1458     1 */

          /* XXX 5 bytes hole, try to pack */

          struct dev_ext_attribute * ea;                   /*  1464     8 */

          /* size: 1472, cachelines: 23, members: 12 */
          /* sum members: 1463, holes: 2, sum holes: 9 */
          /* paddings: 1, sum paddings: 7 */
  };
  root@d15263e5734a:/git/perf#

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/20190131184714.20388-3-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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mathieupoirier authored and acmel committed Feb 6, 2019
1 parent 8400186 commit bb8e370
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Showing 4 changed files with 110 additions and 3 deletions.
82 changes: 82 additions & 0 deletions drivers/hwtracing/coresight/coresight-etm-perf.c
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@
#include <linux/perf_event.h>
#include <linux/percpu-defs.h>
#include <linux/slab.h>
#include <linux/stringhash.h>
#include <linux/types.h>
#include <linux/workqueue.h>

Expand Down Expand Up @@ -43,8 +44,18 @@ static const struct attribute_group etm_pmu_format_group = {
.attrs = etm_config_formats_attr,
};

static struct attribute *etm_config_sinks_attr[] = {
NULL,
};

static const struct attribute_group etm_pmu_sinks_group = {
.name = "sinks",
.attrs = etm_config_sinks_attr,
};

static const struct attribute_group *etm_pmu_attr_groups[] = {
&etm_pmu_format_group,
&etm_pmu_sinks_group,
NULL,
};

Expand Down Expand Up @@ -479,6 +490,77 @@ int etm_perf_symlink(struct coresight_device *csdev, bool link)
return 0;
}

static ssize_t etm_perf_sink_name_show(struct device *dev,
struct device_attribute *dattr,
char *buf)
{
struct dev_ext_attribute *ea;

ea = container_of(dattr, struct dev_ext_attribute, attr);
return scnprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)(ea->var));
}

int etm_perf_add_symlink_sink(struct coresight_device *csdev)
{
int ret;
unsigned long hash;
const char *name;
struct device *pmu_dev = etm_pmu.dev;
struct device *pdev = csdev->dev.parent;
struct dev_ext_attribute *ea;

if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
return -EINVAL;

if (csdev->ea != NULL)
return -EINVAL;

if (!etm_perf_up)
return -EPROBE_DEFER;

ea = devm_kzalloc(pdev, sizeof(*ea), GFP_KERNEL);
if (!ea)
return -ENOMEM;

name = dev_name(pdev);
/* See function coresight_get_sink_by_id() to know where this is used */
hash = hashlen_hash(hashlen_string(NULL, name));

ea->attr.attr.name = devm_kstrdup(pdev, name, GFP_KERNEL);
if (!ea->attr.attr.name)
return -ENOMEM;

ea->attr.attr.mode = 0444;
ea->attr.show = etm_perf_sink_name_show;
ea->var = (unsigned long *)hash;

ret = sysfs_add_file_to_group(&pmu_dev->kobj,
&ea->attr.attr, "sinks");

if (!ret)
csdev->ea = ea;

return ret;
}

void etm_perf_del_symlink_sink(struct coresight_device *csdev)
{
struct device *pmu_dev = etm_pmu.dev;
struct dev_ext_attribute *ea = csdev->ea;

if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
return;

if (!ea)
return;

sysfs_remove_file_from_group(&pmu_dev->kobj,
&ea->attr.attr, "sinks");
csdev->ea = NULL;
}

static int __init etm_perf_init(void)
{
int ret;
Expand Down
6 changes: 5 additions & 1 deletion drivers/hwtracing/coresight/coresight-etm-perf.h
Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,8 @@ struct etm_event_data {

#ifdef CONFIG_CORESIGHT
int etm_perf_symlink(struct coresight_device *csdev, bool link);
int etm_perf_add_symlink_sink(struct coresight_device *csdev);
void etm_perf_del_symlink_sink(struct coresight_device *csdev);
static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
{
struct etm_event_data *data = perf_get_aux(handle);
Expand All @@ -70,7 +72,9 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
#else
static inline int etm_perf_symlink(struct coresight_device *csdev, bool link)
{ return -EINVAL; }

int etm_perf_add_symlink_sink(struct coresight_device *csdev)
{ return -EINVAL; }
void etm_perf_del_symlink_sink(struct coresight_device *csdev) {}
static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
{
return NULL;
Expand Down
18 changes: 18 additions & 0 deletions drivers/hwtracing/coresight/coresight.c
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@
#include <linux/delay.h>
#include <linux/pm_runtime.h>

#include "coresight-etm-perf.h"
#include "coresight-priv.h"

static DEFINE_MUTEX(coresight_mutex);
Expand Down Expand Up @@ -1167,6 +1168,22 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
goto err_out;
}

if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
ret = etm_perf_add_symlink_sink(csdev);

if (ret) {
device_unregister(&csdev->dev);
/*
* As with the above, all resources are free'd
* explicitly via coresight_device_release() triggered
* from put_device(), which is in turn called from
* function device_unregister().
*/
goto err_out;
}
}

mutex_lock(&coresight_mutex);

coresight_fixup_device_conns(csdev);
Expand All @@ -1185,6 +1202,7 @@ EXPORT_SYMBOL_GPL(coresight_register);

void coresight_unregister(struct coresight_device *csdev)
{
etm_perf_del_symlink_sink(csdev);
/* Remove references of that device in the topology */
coresight_remove_conns(csdev);
device_unregister(&csdev->dev);
Expand Down
7 changes: 5 additions & 2 deletions include/linux/coresight.h
Original file line number Diff line number Diff line change
Expand Up @@ -154,8 +154,9 @@ struct coresight_connection {
* @orphan: true if the component has connections that haven't been linked.
* @enable: 'true' if component is currently part of an active path.
* @activated: 'true' only if a _sink_ has been activated. A sink can be
activated but not yet enabled. Enabling for a _sink_
happens when a source has been selected for that it.
* activated but not yet enabled. Enabling for a _sink_
* appens when a source has been selected for that it.
* @ea: Device attribute for sink representation under PMU directory.
*/
struct coresight_device {
struct coresight_connection *conns;
Expand All @@ -168,7 +169,9 @@ struct coresight_device {
atomic_t *refcnt;
bool orphan;
bool enable; /* true only if configured as part of a path */
/* sink specific fields */
bool activated; /* true only if a sink is part of a path */
struct dev_ext_attribute *ea;
};

#define to_coresight_device(d) container_of(d, struct coresight_device, dev)
Expand Down

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