From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: gregkh@linuxfoundation.org
Cc: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 03/23] coresight: Add generic sysfs link creation functions
Date: Mon, 18 May 2020 12:02:22 -0600 [thread overview]
Message-ID: <20200518180242.7916-4-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20200518180242.7916-1-mathieu.poirier@linaro.org>
From: Mike Leach <mike.leach@linaro.org>
To allow the connections between coresight components to be represented
in sysfs, generic methods for creating sysfs links between two coresight
devices are added.
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/hwtracing/coresight/Makefile | 3 +-
drivers/hwtracing/coresight/coresight-priv.h | 4 +
drivers/hwtracing/coresight/coresight-sysfs.c | 124 ++++++++++++++++++
include/linux/coresight.h | 20 +++
4 files changed, 150 insertions(+), 1 deletion(-)
create mode 100644 drivers/hwtracing/coresight/coresight-sysfs.c
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 0e3e72f0f510..19497d1d92bf 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -2,7 +2,8 @@
#
# Makefile for CoreSight drivers.
#
-obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o coresight-platform.o
+obj-$(CONFIG_CORESIGHT) += coresight.o coresight-etm-perf.o \
+ coresight-platform.o coresight-sysfs.o
obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o \
coresight-tmc-etf.o \
coresight-tmc-etr.o
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 1cad642f27aa..a4a658d46045 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -153,6 +153,10 @@ struct coresight_device *coresight_get_sink_by_id(u32 id);
struct list_head *coresight_build_path(struct coresight_device *csdev,
struct coresight_device *sink);
void coresight_release_path(struct list_head *path);
+int coresight_add_sysfs_link(struct coresight_sysfs_link *info);
+void coresight_remove_sysfs_link(struct coresight_sysfs_link *info);
+int coresight_create_conns_sysfs_group(struct coresight_device *csdev);
+void coresight_remove_conns_sysfs_group(struct coresight_device *csdev);
#ifdef CONFIG_CORESIGHT_SOURCE_ETM3X
extern int etm_readl_cp14(u32 off, unsigned int *val);
diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
new file mode 100644
index 000000000000..6759f78733ab
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019, Linaro Limited, All rights reserved.
+ * Author: Mike Leach <mike.leach@linaro.org>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+
+#include "coresight-priv.h"
+
+/*
+ * Connections group - links attribute.
+ * Count of created links between coresight components in the group.
+ */
+static ssize_t nr_links_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct coresight_device *csdev = to_coresight_device(dev);
+
+ return sprintf(buf, "%d\n", csdev->nr_links);
+}
+static DEVICE_ATTR_RO(nr_links);
+
+static struct attribute *coresight_conns_attrs[] = {
+ &dev_attr_nr_links.attr,
+ NULL,
+};
+
+static struct attribute_group coresight_conns_group = {
+ .attrs = coresight_conns_attrs,
+ .name = "connections",
+};
+
+/*
+ * Create connections group for CoreSight devices.
+ * This group will then be used to collate the sysfs links between
+ * devices.
+ */
+int coresight_create_conns_sysfs_group(struct coresight_device *csdev)
+{
+ int ret = 0;
+
+ if (!csdev)
+ return -EINVAL;
+
+ ret = sysfs_create_group(&csdev->dev.kobj, &coresight_conns_group);
+ if (ret)
+ return ret;
+
+ csdev->has_conns_grp = true;
+ return ret;
+}
+
+void coresight_remove_conns_sysfs_group(struct coresight_device *csdev)
+{
+ if (!csdev)
+ return;
+
+ if (csdev->has_conns_grp) {
+ sysfs_remove_group(&csdev->dev.kobj, &coresight_conns_group);
+ csdev->has_conns_grp = false;
+ }
+}
+
+int coresight_add_sysfs_link(struct coresight_sysfs_link *info)
+{
+ int ret = 0;
+
+ if (!info)
+ return -EINVAL;
+ if (!info->orig || !info->target ||
+ !info->orig_name || !info->target_name)
+ return -EINVAL;
+ if (!info->orig->has_conns_grp || !info->target->has_conns_grp)
+ return -EINVAL;
+
+ /* first link orig->target */
+ ret = sysfs_add_link_to_group(&info->orig->dev.kobj,
+ coresight_conns_group.name,
+ &info->target->dev.kobj,
+ info->orig_name);
+ if (ret)
+ return ret;
+
+ /* second link target->orig */
+ ret = sysfs_add_link_to_group(&info->target->dev.kobj,
+ coresight_conns_group.name,
+ &info->orig->dev.kobj,
+ info->target_name);
+
+ /* error in second link - remove first - otherwise inc counts */
+ if (ret) {
+ sysfs_remove_link_from_group(&info->orig->dev.kobj,
+ coresight_conns_group.name,
+ info->orig_name);
+ } else {
+ info->orig->nr_links++;
+ info->target->nr_links++;
+ }
+
+ return ret;
+}
+
+void coresight_remove_sysfs_link(struct coresight_sysfs_link *info)
+{
+ if (!info)
+ return;
+ if (!info->orig || !info->target ||
+ !info->orig_name || !info->target_name)
+ return;
+
+ sysfs_remove_link_from_group(&info->orig->dev.kobj,
+ coresight_conns_group.name,
+ info->orig_name);
+
+ sysfs_remove_link_from_group(&info->target->dev.kobj,
+ coresight_conns_group.name,
+ info->target_name);
+
+ info->orig->nr_links--;
+ info->target->nr_links--;
+}
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 193cc9dbf448..a2ec25e02ca9 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -148,6 +148,20 @@ struct coresight_connection {
struct coresight_device *child_dev;
};
+/**
+ * struct coresight_sysfs_link - representation of a connection in sysfs.
+ * @orig: Originating (master) coresight device for the link.
+ * @orig_name: Name to use for the link orig->target.
+ * @target: Target (slave) coresight device for the link.
+ * @target_name: Name to use for the link target->orig.
+ */
+struct coresight_sysfs_link {
+ struct coresight_device *orig;
+ const char *orig_name;
+ struct coresight_device *target;
+ const char *target_name;
+};
+
/**
* struct coresight_device - representation of a device as used by the framework
* @pdata: Platform data with device connections associated to this device.
@@ -165,6 +179,9 @@ struct coresight_connection {
* @ea: Device attribute for sink representation under PMU directory.
* @ect_dev: Associated cross trigger device. Not part of the trace data
* path or connections.
+ * @nr_links: number of sysfs links created to other components from this
+ * device. These will appear in the "connections" group.
+ * @has_conns_grp: Have added a "connections" group for sysfs links.
*/
struct coresight_device {
struct coresight_platform_data *pdata;
@@ -180,6 +197,9 @@ struct coresight_device {
struct dev_ext_attribute *ea;
/* cross trigger handling */
struct coresight_device *ect_dev;
+ /* sysfs links between components */
+ int nr_links;
+ bool has_conns_grp;
};
/*
--
2.20.1
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next prev parent reply other threads:[~2020-05-18 18:04 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-18 18:02 [PATCH 00/23] coresight: next for v5.8 Mathieu Poirier
2020-05-18 18:02 ` [PATCH 01/23] coresight: Pass coresight_device for coresight_release_platform_data Mathieu Poirier
2020-05-18 18:02 ` [PATCH 02/23] coresight: Add return value for fixup connections Mathieu Poirier
2020-05-18 18:02 ` Mathieu Poirier [this message]
2020-05-18 18:02 ` [PATCH 04/23] coresight: Expose device connections via sysfs Mathieu Poirier
2020-05-18 18:02 ` [PATCH 05/23] coresight: cti: Add in sysfs links to other coresight devices Mathieu Poirier
2020-05-18 18:02 ` [PATCH 06/23] coresight: docs: Add information about the topology representations Mathieu Poirier
2020-05-18 18:02 ` [PATCH 07/23] docs: trace: coresight-ect.rst: Fix a build warning Mathieu Poirier
2020-05-18 18:02 ` [PATCH 08/23] coresight: etm4x: Add support for Qualcomm SC7180 SoC Mathieu Poirier
2020-05-18 18:02 ` [PATCH 09/23] coresight: etm4x: Replace ETM PIDs with UCI IDs for Kryo385 Mathieu Poirier
2020-05-18 18:02 ` [PATCH 10/23] coresight: cti: Make some symbols static Mathieu Poirier
2020-05-18 18:02 ` [PATCH 11/23] coresight: etb10: Make coresight_etb_groups static Mathieu Poirier
2020-05-18 18:02 ` [PATCH 12/23] coresight: Fix support for sparsely populated ports Mathieu Poirier
2020-05-18 18:02 ` [PATCH 13/23] coresight: tmc: Fix TMC mode read in tmc_read_prepare_etb() Mathieu Poirier
2020-05-18 18:02 ` [PATCH 14/23] coresight: etmv4: Update default filter and initialisation Mathieu Poirier
2020-05-18 18:02 ` [PATCH 15/23] coresight: etm4x: Add support for Neoverse N1 ETM Mathieu Poirier
2020-05-18 18:02 ` [PATCH 16/23] coresight: Mark some functions static Mathieu Poirier
2020-05-18 18:02 ` [PATCH 17/23] coresight: Don't initialize variables unnecessarily Mathieu Poirier
2020-05-18 18:02 ` [PATCH 18/23] coresight: Initialize arg in sparse friendly way Mathieu Poirier
2020-05-18 18:02 ` [PATCH 19/23] coresight: Include required headers in C files Mathieu Poirier
2020-05-18 18:02 ` [PATCH 20/23] coresight: Avoid casting void pointers Mathieu Poirier
2020-05-18 18:02 ` [PATCH 21/23] coresight: etm4x: Fix use-after-free of per-cpu etm drvdata Mathieu Poirier
2020-05-19 14:32 ` Greg KH
2020-05-18 18:02 ` [PATCH 22/23] coresight: cti: Add CPU Hotplug handling to CTI driver Mathieu Poirier
2020-05-18 18:02 ` [PATCH 23/23] coresight: cti: Add CPU idle pm notifer to CTI devices Mathieu Poirier
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