| Message ID | 20200211105808.27884-4-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Describe CoreSight topology using sysfs links. | expand |
On Tue, Feb 11, 2020 at 10:58:05AM +0000, Mike Leach wrote: > 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> > --- > 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..17d565941e5e > --- /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 scnprintf(buf, PAGE_SIZE, "%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; The only place coresight_create_conns_sysfs_group() is used is in coresight_register() where an error is returned to driver probe() functions if an error occurs. Have you found places where csdev->has_conns_grp is needed? If not please remove. > + 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; > }; With the above: Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > /* > -- > 2.17.1 >
Hi Mathieu, On Fri, 14 Feb 2020 at 23:17, Mathieu Poirier <mathieu.poirier@linaro.org> wrote: > > On Tue, Feb 11, 2020 at 10:58:05AM +0000, Mike Leach wrote: > > 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> > > --- > > 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..17d565941e5e > > --- /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 scnprintf(buf, PAGE_SIZE, "%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; > > The only place coresight_create_conns_sysfs_group() is used is in > coresight_register() where an error is returned to driver probe() functions if > an error occurs. Have you found places where csdev->has_conns_grp is needed? > If not please remove. > There is a sequence of calls in coresight_register() which occur after the coresight_create_conns_sysfs_group() - any one of which may throw an error resulting in an immediate coresight_unregister() and hence coresight_release_platform_data() => coresight_remove_conns_sysfs_group(). There is also an alternate path through coresight_register() which also results in coresight_release_platform_data() occurring before we have created the group. The flag ensures that both paths clean up the sysfs connection data correctly and safely. Regards Mike > > + 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; > > }; > > With the above: > > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > > > > /* > > -- > > 2.17.1 > >
On Tue, 25 Feb 2020 at 08:46, Mike Leach <mike.leach@linaro.org> wrote: > > Hi Mathieu, > > On Fri, 14 Feb 2020 at 23:17, Mathieu Poirier > <mathieu.poirier@linaro.org> wrote: > > > > On Tue, Feb 11, 2020 at 10:58:05AM +0000, Mike Leach wrote: > > > 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> > > > --- > > > 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..17d565941e5e > > > --- /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 scnprintf(buf, PAGE_SIZE, "%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; > > > > The only place coresight_create_conns_sysfs_group() is used is in > > coresight_register() where an error is returned to driver probe() functions if > > an error occurs. Have you found places where csdev->has_conns_grp is needed? > > If not please remove. > > > > There is a sequence of calls in coresight_register() which occur after > the coresight_create_conns_sysfs_group() - > any one of which may throw an error resulting in an immediate > coresight_unregister() and hence > coresight_release_platform_data() => coresight_remove_conns_sysfs_group(). > There is also an alternate path through coresight_register() which > also results in coresight_release_platform_data() occurring before we > have created the group. > The flag ensures that both paths clean up the sysfs connection data > correctly and safely. I see the real problem is with the WARN() that is thrown in sysfs_remove_group() when a group has not been created, and we can't have that. I think what you did is fine. Mathieu > > Regards > > Mike > > > > + 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; > > > }; > > > > With the above: > > > > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > > > > > > > /* > > > -- > > > 2.17.1 > > > > > > > -- > Mike Leach > Principal Engineer, ARM Ltd. > Manchester Design Centre. UK
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..17d565941e5e --- /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 scnprintf(buf, PAGE_SIZE, "%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; }; /*