| Message ID | 20241217063324.33781-3-quic_jinlmao@quicinc.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | coresight: Add label sysfs node support | expand |
On 17/12/2024 06:33, Mao Jinlong wrote: > For some coresight components like CTI and TPDM, there could be > numerous of them. From the node name, we can only get the type and > register address of the component. We can't identify the HW or the > system the component belongs to. Add label sysfs node support for > showing the intuitive name of the device. > > Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> > --- > .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ > .../sysfs-bus-coresight-devices-funnel | 6 ++++ > .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ > drivers/hwtracing/coresight/coresight-sysfs.c | 32 +++++++++++++++++++ > 4 files changed, 50 insertions(+) Do you think we need to name the devices using the label ? Or is this enough ? Suzuki > > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > index bf2869c413e7..909670e0451a 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > @@ -239,3 +239,9 @@ Date: March 2020 > KernelVersion 5.7 > Contact: Mike Leach or Mathieu Poirier > Description: (Write) Clear all channel / trigger programming. > + > +What: /sys/bus/coresight/devices/<cti-name>/label > +Date: Dec 2024 > +KernelVersion 6.14 > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > +Description: (Read) Show hardware context information of device. > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > index d75acda5e1b3..944aad879aeb 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > @@ -10,3 +10,9 @@ Date: November 2014 > KernelVersion: 3.19 > Contact: Mathieu Poirier <mathieu.poirier@linaro.org> > Description: (RW) Defines input port priority order. > + > +What: /sys/bus/coresight/devices/<memory_map>.funnel/label > +Date: Dec 2024 > +KernelVersion 6.14 > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > +Description: (Read) Show hardware context information of device. > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > index bf710ea6e0ef..309802246398 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t > Description: > (RW) Set/Get the MSR(mux select register) for the CMB subunit > TPDM. > + > +What: /sys/bus/coresight/devices/<tpdm-name>/label > +Date: Dec 2024 > +KernelVersion 6.14 > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > +Description: (Read) Show hardware context information of device. > diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c > index a01c9e54e2ed..4af40cd7d75a 100644 > --- a/drivers/hwtracing/coresight/coresight-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > @@ -7,6 +7,7 @@ > #include <linux/device.h> > #include <linux/idr.h> > #include <linux/kernel.h> > +#include <linux/property.h> > > #include "coresight-priv.h" > #include "coresight-trace-id.h" > @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device *dev, > } > static DEVICE_ATTR_RW(enable_source); > > +static ssize_t label_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + > + const char *str; > + int ret = 0; > + > + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); > + if (ret == 0) > + return scnprintf(buf, PAGE_SIZE, "%s\n", str); > + else > + return ret; > +} > +static DEVICE_ATTR_RO(label); > + > static struct attribute *coresight_sink_attrs[] = { > &dev_attr_enable_sink.attr, > + &dev_attr_label.attr, > NULL, > }; > ATTRIBUTE_GROUPS(coresight_sink); > > static struct attribute *coresight_source_attrs[] = { > &dev_attr_enable_source.attr, > + &dev_attr_label.attr, > NULL, > }; > ATTRIBUTE_GROUPS(coresight_source); > > +static struct attribute *coresight_link_attrs[] = { > + &dev_attr_label.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(coresight_link); > + > +static struct attribute *coresight_helper_attrs[] = { > + &dev_attr_label.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(coresight_helper); > + > const struct device_type coresight_dev_type[] = { > [CORESIGHT_DEV_TYPE_SINK] = { > .name = "sink", > @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { > }, > [CORESIGHT_DEV_TYPE_LINK] = { > .name = "link", > + .groups = coresight_link_groups, > }, > [CORESIGHT_DEV_TYPE_LINKSINK] = { > .name = "linksink", > @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { > }, > [CORESIGHT_DEV_TYPE_HELPER] = { > .name = "helper", > + .groups = coresight_helper_groups, > } > }; > /* Ensure the enum matches the names and groups */
Hi > -----Original Message----- > From: Suzuki K Poulose <suzuki.poulose@arm.com> > Sent: Wednesday, December 18, 2024 9:38 AM > To: Mao Jinlong <quic_jinlmao@quicinc.com>; Mike Leach > <mike.leach@linaro.org>; James Clark <James.Clark@arm.com>; Rob Herring > <robh@kernel.org>; Krzysztof Kozlowski <krzk+dt@kernel.org>; Conor Dooley > <conor+dt@kernel.org>; Mathieu Poirier <mathieu.poirier@linaro.org>; Bjorn > Andersson <andersson@kernel.org>; Konrad Dybcio > <konradybcio@kernel.org> > Cc: coresight@lists.linaro.org; linux-arm-kernel@lists.infradead.org; > devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm- > msm@vger.kernel.org > Subject: Re: [PATCH v6 2/2] coresight: Add label sysfs node support > > On 17/12/2024 06:33, Mao Jinlong wrote: > > For some coresight components like CTI and TPDM, there could be > > numerous of them. From the node name, we can only get the type and > > register address of the component. We can't identify the HW or the > > system the component belongs to. Add label sysfs node support for > > showing the intuitive name of the device. > > > > Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> > > --- > > .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ > > .../sysfs-bus-coresight-devices-funnel | 6 ++++ > > .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ > > drivers/hwtracing/coresight/coresight-sysfs.c | 32 > +++++++++++++++++++ > > 4 files changed, 50 insertions(+) > > Do you think we need to name the devices using the label ? > No - absolutely not. If we use label to name devices then we have to validate that the string is a correctly formed device name and that it has not been previously used. Using the canonical driver selected names works best as we are guaranteed a unique name and the information label can be used to provide flexible context information that best matches the users requirements. Mike > Or is this enough ? > Suzuki > > > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > > b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > > index bf2869c413e7..909670e0451a 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > > @@ -239,3 +239,9 @@ Date: March 2020 > > KernelVersion 5.7 > > Contact: Mike Leach or Mathieu Poirier > > Description: (Write) Clear all channel / trigger programming. > > + > > +What: /sys/bus/coresight/devices/<cti-name>/label > > +Date: Dec 2024 > > +KernelVersion 6.14 > > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > > +Description: (Read) Show hardware context information of device. > > diff --git > > a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > > b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > > index d75acda5e1b3..944aad879aeb 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > > @@ -10,3 +10,9 @@ Date: November 2014 > > KernelVersion: 3.19 > > Contact: Mathieu Poirier <mathieu.poirier@linaro.org> > > Description: (RW) Defines input port priority order. > > + > > +What: /sys/bus/coresight/devices/<memory_map>.funnel/label > > +Date: Dec 2024 > > +KernelVersion 6.14 > > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > > +Description: (Read) Show hardware context information of device. > > diff --git > > a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > > b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > > index bf710ea6e0ef..309802246398 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > > @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) > <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t > > Description: > > (RW) Set/Get the MSR(mux select register) for the CMB > subunit > > TPDM. > > + > > +What: /sys/bus/coresight/devices/<tpdm-name>/label > > +Date: Dec 2024 > > +KernelVersion 6.14 > > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > > +Description: (Read) Show hardware context information of device. > > diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c > > b/drivers/hwtracing/coresight/coresight-sysfs.c > > index a01c9e54e2ed..4af40cd7d75a 100644 > > --- a/drivers/hwtracing/coresight/coresight-sysfs.c > > +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > > @@ -7,6 +7,7 @@ > > #include <linux/device.h> > > #include <linux/idr.h> > > #include <linux/kernel.h> > > +#include <linux/property.h> > > > > #include "coresight-priv.h" > > #include "coresight-trace-id.h" > > @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device > *dev, > > } > > static DEVICE_ATTR_RW(enable_source); > > > > +static ssize_t label_show(struct device *dev, > > + struct device_attribute *attr, char *buf) { > > + > > + const char *str; > > + int ret = 0; > > + > > + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); > > + if (ret == 0) > > + return scnprintf(buf, PAGE_SIZE, "%s\n", str); > > + else > > + return ret; > > +} > > +static DEVICE_ATTR_RO(label); > > + > > static struct attribute *coresight_sink_attrs[] = { > > &dev_attr_enable_sink.attr, > > + &dev_attr_label.attr, > > NULL, > > }; > > ATTRIBUTE_GROUPS(coresight_sink); > > > > static struct attribute *coresight_source_attrs[] = { > > &dev_attr_enable_source.attr, > > + &dev_attr_label.attr, > > NULL, > > }; > > ATTRIBUTE_GROUPS(coresight_source); > > > > +static struct attribute *coresight_link_attrs[] = { > > + &dev_attr_label.attr, > > + NULL, > > +}; > > +ATTRIBUTE_GROUPS(coresight_link); > > + > > +static struct attribute *coresight_helper_attrs[] = { > > + &dev_attr_label.attr, > > + NULL, > > +}; > > +ATTRIBUTE_GROUPS(coresight_helper); > > + > > const struct device_type coresight_dev_type[] = { > > [CORESIGHT_DEV_TYPE_SINK] = { > > .name = "sink", > > @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { > > }, > > [CORESIGHT_DEV_TYPE_LINK] = { > > .name = "link", > > + .groups = coresight_link_groups, > > }, > > [CORESIGHT_DEV_TYPE_LINKSINK] = { > > .name = "linksink", > > @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { > > }, > > [CORESIGHT_DEV_TYPE_HELPER] = { > > .name = "helper", > > + .groups = coresight_helper_groups, > > } > > }; > > /* Ensure the enum matches the names and groups */ > > _______________________________________________ > CoreSight mailing list -- coresight@lists.linaro.org To unsubscribe send an > email to coresight-leave@lists.linaro.org
On 2024/12/18 17:38, Suzuki K Poulose wrote: > On 17/12/2024 06:33, Mao Jinlong wrote: >> For some coresight components like CTI and TPDM, there could be >> numerous of them. From the node name, we can only get the type and >> register address of the component. We can't identify the HW or the >> system the component belongs to. Add label sysfs node support for >> showing the intuitive name of the device. >> >> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> >> --- >> .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ >> .../sysfs-bus-coresight-devices-funnel | 6 ++++ >> .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ >> drivers/hwtracing/coresight/coresight-sysfs.c | 32 +++++++++++++++++++ >> 4 files changed, 50 insertions(+) > > Do you think we need to name the devices using the label ? Or is this > enough ? > > Suzuki Hi Suzuki, In my opinion, we should use label as the device name. It will be easier to identify the component with the folder name in /sys/bus/coresight/devices/ Thanks Jinlong Mao > > >> >> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >> index bf2869c413e7..909670e0451a 100644 >> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >> @@ -239,3 +239,9 @@ Date: March 2020 >> KernelVersion 5.7 >> Contact: Mike Leach or Mathieu Poirier >> Description: (Write) Clear all channel / trigger programming. >> + >> +What: /sys/bus/coresight/devices/<cti-name>/label >> +Date: Dec 2024 >> +KernelVersion 6.14 >> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >> +Description: (Read) Show hardware context information of device. >> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices- >> funnel b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >> index d75acda5e1b3..944aad879aeb 100644 >> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >> @@ -10,3 +10,9 @@ Date: November 2014 >> KernelVersion: 3.19 >> Contact: Mathieu Poirier <mathieu.poirier@linaro.org> >> Description: (RW) Defines input port priority order. >> + >> +What: /sys/bus/coresight/devices/<memory_map>.funnel/label >> +Date: Dec 2024 >> +KernelVersion 6.14 >> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >> +Description: (Read) Show hardware context information of device. >> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices- >> tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >> index bf710ea6e0ef..309802246398 100644 >> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >> @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) >> <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t >> Description: >> (RW) Set/Get the MSR(mux select register) for the CMB subunit >> TPDM. >> + >> +What: /sys/bus/coresight/devices/<tpdm-name>/label >> +Date: Dec 2024 >> +KernelVersion 6.14 >> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >> +Description: (Read) Show hardware context information of device. >> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/ >> hwtracing/coresight/coresight-sysfs.c >> index a01c9e54e2ed..4af40cd7d75a 100644 >> --- a/drivers/hwtracing/coresight/coresight-sysfs.c >> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c >> @@ -7,6 +7,7 @@ >> #include <linux/device.h> >> #include <linux/idr.h> >> #include <linux/kernel.h> >> +#include <linux/property.h> >> #include "coresight-priv.h" >> #include "coresight-trace-id.h" >> @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device >> *dev, >> } >> static DEVICE_ATTR_RW(enable_source); >> +static ssize_t label_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + >> + const char *str; >> + int ret = 0; >> + >> + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); >> + if (ret == 0) >> + return scnprintf(buf, PAGE_SIZE, "%s\n", str); >> + else >> + return ret; >> +} >> +static DEVICE_ATTR_RO(label); >> + >> static struct attribute *coresight_sink_attrs[] = { >> &dev_attr_enable_sink.attr, >> + &dev_attr_label.attr, >> NULL, >> }; >> ATTRIBUTE_GROUPS(coresight_sink); >> static struct attribute *coresight_source_attrs[] = { >> &dev_attr_enable_source.attr, >> + &dev_attr_label.attr, >> NULL, >> }; >> ATTRIBUTE_GROUPS(coresight_source); >> +static struct attribute *coresight_link_attrs[] = { >> + &dev_attr_label.attr, >> + NULL, >> +}; >> +ATTRIBUTE_GROUPS(coresight_link); >> + >> +static struct attribute *coresight_helper_attrs[] = { >> + &dev_attr_label.attr, >> + NULL, >> +}; >> +ATTRIBUTE_GROUPS(coresight_helper); >> + >> const struct device_type coresight_dev_type[] = { >> [CORESIGHT_DEV_TYPE_SINK] = { >> .name = "sink", >> @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { >> }, >> [CORESIGHT_DEV_TYPE_LINK] = { >> .name = "link", >> + .groups = coresight_link_groups, >> }, >> [CORESIGHT_DEV_TYPE_LINKSINK] = { >> .name = "linksink", >> @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { >> }, >> [CORESIGHT_DEV_TYPE_HELPER] = { >> .name = "helper", >> + .groups = coresight_helper_groups, >> } >> }; >> /* Ensure the enum matches the names and groups */ >
Hi On Wed, 18 Dec 2024 at 09:57, Jinlong Mao <quic_jinlmao@quicinc.com> wrote: > > > > On 2024/12/18 17:38, Suzuki K Poulose wrote: > > On 17/12/2024 06:33, Mao Jinlong wrote: > >> For some coresight components like CTI and TPDM, there could be > >> numerous of them. From the node name, we can only get the type and > >> register address of the component. We can't identify the HW or the > >> system the component belongs to. Add label sysfs node support for > >> showing the intuitive name of the device. > >> > >> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> > >> --- > >> .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ > >> .../sysfs-bus-coresight-devices-funnel | 6 ++++ > >> .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ > >> drivers/hwtracing/coresight/coresight-sysfs.c | 32 +++++++++++++++++++ > >> 4 files changed, 50 insertions(+) > > > > Do you think we need to name the devices using the label ? Or is this > > enough ? > > > > Suzuki > Hi Suzuki, > > In my opinion, we should use label as the device name. > > It will be easier to identify the component with the folder name in > /sys/bus/coresight/devices/ > > Please see the my comments from v4 of this patchset that explains why this should not be done- re uniqueness and allowing scripting to work:- https://lists.linaro.org/archives/list/coresight@lists.linaro.org/message/Y65RKVUJUQGNARMWCOLSD636K7LROLYA/ Mike > Thanks > Jinlong Mao > > > > > > >> > >> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >> index bf2869c413e7..909670e0451a 100644 > >> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >> @@ -239,3 +239,9 @@ Date: March 2020 > >> KernelVersion 5.7 > >> Contact: Mike Leach or Mathieu Poirier > >> Description: (Write) Clear all channel / trigger programming. > >> + > >> +What: /sys/bus/coresight/devices/<cti-name>/label > >> +Date: Dec 2024 > >> +KernelVersion 6.14 > >> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > >> +Description: (Read) Show hardware context information of device. > >> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices- > >> funnel b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > >> index d75acda5e1b3..944aad879aeb 100644 > >> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > >> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > >> @@ -10,3 +10,9 @@ Date: November 2014 > >> KernelVersion: 3.19 > >> Contact: Mathieu Poirier <mathieu.poirier@linaro.org> > >> Description: (RW) Defines input port priority order. > >> + > >> +What: /sys/bus/coresight/devices/<memory_map>.funnel/label > >> +Date: Dec 2024 > >> +KernelVersion 6.14 > >> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > >> +Description: (Read) Show hardware context information of device. > >> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices- > >> tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > >> index bf710ea6e0ef..309802246398 100644 > >> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > >> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > >> @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) > >> <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t > >> Description: > >> (RW) Set/Get the MSR(mux select register) for the CMB subunit > >> TPDM. > >> + > >> +What: /sys/bus/coresight/devices/<tpdm-name>/label > >> +Date: Dec 2024 > >> +KernelVersion 6.14 > >> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > >> +Description: (Read) Show hardware context information of device. > >> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/ > >> hwtracing/coresight/coresight-sysfs.c > >> index a01c9e54e2ed..4af40cd7d75a 100644 > >> --- a/drivers/hwtracing/coresight/coresight-sysfs.c > >> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > >> @@ -7,6 +7,7 @@ > >> #include <linux/device.h> > >> #include <linux/idr.h> > >> #include <linux/kernel.h> > >> +#include <linux/property.h> > >> #include "coresight-priv.h" > >> #include "coresight-trace-id.h" > >> @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device > >> *dev, > >> } > >> static DEVICE_ATTR_RW(enable_source); > >> +static ssize_t label_show(struct device *dev, > >> + struct device_attribute *attr, char *buf) > >> +{ > >> + > >> + const char *str; > >> + int ret = 0; > >> + > >> + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); > >> + if (ret == 0) > >> + return scnprintf(buf, PAGE_SIZE, "%s\n", str); > >> + else > >> + return ret; > >> +} > >> +static DEVICE_ATTR_RO(label); > >> + > >> static struct attribute *coresight_sink_attrs[] = { > >> &dev_attr_enable_sink.attr, > >> + &dev_attr_label.attr, > >> NULL, > >> }; > >> ATTRIBUTE_GROUPS(coresight_sink); > >> static struct attribute *coresight_source_attrs[] = { > >> &dev_attr_enable_source.attr, > >> + &dev_attr_label.attr, > >> NULL, > >> }; > >> ATTRIBUTE_GROUPS(coresight_source); > >> +static struct attribute *coresight_link_attrs[] = { > >> + &dev_attr_label.attr, > >> + NULL, > >> +}; > >> +ATTRIBUTE_GROUPS(coresight_link); > >> + > >> +static struct attribute *coresight_helper_attrs[] = { > >> + &dev_attr_label.attr, > >> + NULL, > >> +}; > >> +ATTRIBUTE_GROUPS(coresight_helper); > >> + > >> const struct device_type coresight_dev_type[] = { > >> [CORESIGHT_DEV_TYPE_SINK] = { > >> .name = "sink", > >> @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { > >> }, > >> [CORESIGHT_DEV_TYPE_LINK] = { > >> .name = "link", > >> + .groups = coresight_link_groups, > >> }, > >> [CORESIGHT_DEV_TYPE_LINKSINK] = { > >> .name = "linksink", > >> @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { > >> }, > >> [CORESIGHT_DEV_TYPE_HELPER] = { > >> .name = "helper", > >> + .groups = coresight_helper_groups, > >> } > >> }; > >> /* Ensure the enum matches the names and groups */ > > >
Hi On Tue, 17 Dec 2024 at 06:33, Mao Jinlong <quic_jinlmao@quicinc.com> wrote: > > For some coresight components like CTI and TPDM, there could be > numerous of them. From the node name, we can only get the type and > register address of the component. We can't identify the HW or the > system the component belongs to. Add label sysfs node support for > showing the intuitive name of the device. > > Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> > --- > .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ > .../sysfs-bus-coresight-devices-funnel | 6 ++++ > .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ > drivers/hwtracing/coresight/coresight-sysfs.c | 32 +++++++++++++++++++ > 4 files changed, 50 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > index bf2869c413e7..909670e0451a 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > @@ -239,3 +239,9 @@ Date: March 2020 > KernelVersion 5.7 > Contact: Mike Leach or Mathieu Poirier > Description: (Write) Clear all channel / trigger programming. > + > +What: /sys/bus/coresight/devices/<cti-name>/label > +Date: Dec 2024 > +KernelVersion 6.14 > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > +Description: (Read) Show hardware context information of device. > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > index d75acda5e1b3..944aad879aeb 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > @@ -10,3 +10,9 @@ Date: November 2014 > KernelVersion: 3.19 > Contact: Mathieu Poirier <mathieu.poirier@linaro.org> > Description: (RW) Defines input port priority order. > + > +What: /sys/bus/coresight/devices/<memory_map>.funnel/label > +Date: Dec 2024 > +KernelVersion 6.14 > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > +Description: (Read) Show hardware context information of device. > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > index bf710ea6e0ef..309802246398 100644 > --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t > Description: > (RW) Set/Get the MSR(mux select register) for the CMB subunit > TPDM. > + > +What: /sys/bus/coresight/devices/<tpdm-name>/label > +Date: Dec 2024 > +KernelVersion 6.14 > +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > +Description: (Read) Show hardware context information of device. > diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c > index a01c9e54e2ed..4af40cd7d75a 100644 > --- a/drivers/hwtracing/coresight/coresight-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > @@ -7,6 +7,7 @@ > #include <linux/device.h> > #include <linux/idr.h> > #include <linux/kernel.h> > +#include <linux/property.h> > > #include "coresight-priv.h" > #include "coresight-trace-id.h" > @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device *dev, > } > static DEVICE_ATTR_RW(enable_source); > > +static ssize_t label_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + > + const char *str; > + int ret = 0; > + > + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); > + if (ret == 0) > + return scnprintf(buf, PAGE_SIZE, "%s\n", str); > + else > + return ret; > +} > +static DEVICE_ATTR_RO(label); > + > static struct attribute *coresight_sink_attrs[] = { > &dev_attr_enable_sink.attr, > + &dev_attr_label.attr, > NULL, > }; > ATTRIBUTE_GROUPS(coresight_sink); > > static struct attribute *coresight_source_attrs[] = { > &dev_attr_enable_source.attr, > + &dev_attr_label.attr, > NULL, > }; > ATTRIBUTE_GROUPS(coresight_source); > > +static struct attribute *coresight_link_attrs[] = { > + &dev_attr_label.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(coresight_link); > + > +static struct attribute *coresight_helper_attrs[] = { > + &dev_attr_label.attr, > + NULL, > +}; > +ATTRIBUTE_GROUPS(coresight_helper); > + > const struct device_type coresight_dev_type[] = { > [CORESIGHT_DEV_TYPE_SINK] = { > .name = "sink", > @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { > }, > [CORESIGHT_DEV_TYPE_LINK] = { > .name = "link", > + .groups = coresight_link_groups, > }, > [CORESIGHT_DEV_TYPE_LINKSINK] = { > .name = "linksink", > @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { > }, > [CORESIGHT_DEV_TYPE_HELPER] = { > .name = "helper", > + .groups = coresight_helper_groups, > } > }; > /* Ensure the enum matches the names and groups */ > -- > 2.17.1 > This is a clean and simple solution to this issue. In this form... Reviewed-by: Mike Leach <mike.leach@linaro.org>
Hi Mike On 18/12/2024 09:56, Mike Leach wrote: > Hi > >> -----Original Message----- >> From: Suzuki K Poulose <suzuki.poulose@arm.com> >> Sent: Wednesday, December 18, 2024 9:38 AM >> To: Mao Jinlong <quic_jinlmao@quicinc.com>; Mike Leach >> <mike.leach@linaro.org>; James Clark <James.Clark@arm.com>; Rob Herring >> <robh@kernel.org>; Krzysztof Kozlowski <krzk+dt@kernel.org>; Conor Dooley >> <conor+dt@kernel.org>; Mathieu Poirier <mathieu.poirier@linaro.org>; Bjorn >> Andersson <andersson@kernel.org>; Konrad Dybcio >> <konradybcio@kernel.org> >> Cc: coresight@lists.linaro.org; linux-arm-kernel@lists.infradead.org; >> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm- >> msm@vger.kernel.org >> Subject: Re: [PATCH v6 2/2] coresight: Add label sysfs node support >> >> On 17/12/2024 06:33, Mao Jinlong wrote: >>> For some coresight components like CTI and TPDM, there could be >>> numerous of them. From the node name, we can only get the type and >>> register address of the component. We can't identify the HW or the >>> system the component belongs to. Add label sysfs node support for >>> showing the intuitive name of the device. >>> >>> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> >>> --- >>> .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ >>> .../sysfs-bus-coresight-devices-funnel | 6 ++++ >>> .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ >>> drivers/hwtracing/coresight/coresight-sysfs.c | 32 >> +++++++++++++++++++ >>> 4 files changed, 50 insertions(+) >> >> Do you think we need to name the devices using the label ? >> > > No - absolutely not. If we use label to name devices then we have to validate that the string is a correctly formed device name and that it has not been previously used. Anything that doesn't contain '/' can be a device name ? And it is very easy to find if the device name has been used in the coresight bus, after all these devices only appear there. It is as good as : bus_find_device_by_name(coresight_bus_type, NULL, name) == NULL Of course with coresight_mutex() held. Suzuki > > Using the canonical driver selected names works best as we are guaranteed a unique name and the information label can be used to provide flexible context information that best matches the users requirements. > > Mike > >> Or is this enough ? > >> Suzuki >> >> >>> >>> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>> index bf2869c413e7..909670e0451a 100644 >>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>> @@ -239,3 +239,9 @@ Date: March 2020 >>> KernelVersion 5.7 >>> Contact: Mike Leach or Mathieu Poirier >>> Description: (Write) Clear all channel / trigger programming. >>> + >>> +What: /sys/bus/coresight/devices/<cti-name>/label >>> +Date: Dec 2024 >>> +KernelVersion 6.14 >>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >>> +Description: (Read) Show hardware context information of device. >>> diff --git >>> a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>> index d75acda5e1b3..944aad879aeb 100644 >>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>> @@ -10,3 +10,9 @@ Date: November 2014 >>> KernelVersion: 3.19 >>> Contact: Mathieu Poirier <mathieu.poirier@linaro.org> >>> Description: (RW) Defines input port priority order. >>> + >>> +What: /sys/bus/coresight/devices/<memory_map>.funnel/label >>> +Date: Dec 2024 >>> +KernelVersion 6.14 >>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >>> +Description: (Read) Show hardware context information of device. >>> diff --git >>> a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>> index bf710ea6e0ef..309802246398 100644 >>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>> @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) >> <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t >>> Description: >>> (RW) Set/Get the MSR(mux select register) for the CMB >> subunit >>> TPDM. >>> + >>> +What: /sys/bus/coresight/devices/<tpdm-name>/label >>> +Date: Dec 2024 >>> +KernelVersion 6.14 >>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >>> +Description: (Read) Show hardware context information of device. >>> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c >>> b/drivers/hwtracing/coresight/coresight-sysfs.c >>> index a01c9e54e2ed..4af40cd7d75a 100644 >>> --- a/drivers/hwtracing/coresight/coresight-sysfs.c >>> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c >>> @@ -7,6 +7,7 @@ >>> #include <linux/device.h> >>> #include <linux/idr.h> >>> #include <linux/kernel.h> >>> +#include <linux/property.h> >>> >>> #include "coresight-priv.h" >>> #include "coresight-trace-id.h" >>> @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device >> *dev, >>> } >>> static DEVICE_ATTR_RW(enable_source); >>> >>> +static ssize_t label_show(struct device *dev, >>> + struct device_attribute *attr, char *buf) { >>> + >>> + const char *str; >>> + int ret = 0; >>> + >>> + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); >>> + if (ret == 0) >>> + return scnprintf(buf, PAGE_SIZE, "%s\n", str); >>> + else >>> + return ret; >>> +} >>> +static DEVICE_ATTR_RO(label); >>> + >>> static struct attribute *coresight_sink_attrs[] = { >>> &dev_attr_enable_sink.attr, >>> + &dev_attr_label.attr, >>> NULL, >>> }; >>> ATTRIBUTE_GROUPS(coresight_sink); >>> >>> static struct attribute *coresight_source_attrs[] = { >>> &dev_attr_enable_source.attr, >>> + &dev_attr_label.attr, >>> NULL, >>> }; >>> ATTRIBUTE_GROUPS(coresight_source); >>> >>> +static struct attribute *coresight_link_attrs[] = { >>> + &dev_attr_label.attr, >>> + NULL, >>> +}; >>> +ATTRIBUTE_GROUPS(coresight_link); >>> + >>> +static struct attribute *coresight_helper_attrs[] = { >>> + &dev_attr_label.attr, >>> + NULL, >>> +}; >>> +ATTRIBUTE_GROUPS(coresight_helper); >>> + >>> const struct device_type coresight_dev_type[] = { >>> [CORESIGHT_DEV_TYPE_SINK] = { >>> .name = "sink", >>> @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { >>> }, >>> [CORESIGHT_DEV_TYPE_LINK] = { >>> .name = "link", >>> + .groups = coresight_link_groups, >>> }, >>> [CORESIGHT_DEV_TYPE_LINKSINK] = { >>> .name = "linksink", >>> @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { >>> }, >>> [CORESIGHT_DEV_TYPE_HELPER] = { >>> .name = "helper", >>> + .groups = coresight_helper_groups, >>> } >>> }; >>> /* Ensure the enum matches the names and groups */ >> >> _______________________________________________ >> CoreSight mailing list -- coresight@lists.linaro.org To unsubscribe send an >> email to coresight-leave@lists.linaro.org
Hi, On Wed, 18 Dec 2024 at 18:16, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: > > Hi Mike > > On 18/12/2024 09:56, Mike Leach wrote: > > Hi > > > >> -----Original Message----- > >> From: Suzuki K Poulose <suzuki.poulose@arm.com> > >> Sent: Wednesday, December 18, 2024 9:38 AM > >> To: Mao Jinlong <quic_jinlmao@quicinc.com>; Mike Leach > >> <mike.leach@linaro.org>; James Clark <James.Clark@arm.com>; Rob Herring > >> <robh@kernel.org>; Krzysztof Kozlowski <krzk+dt@kernel.org>; Conor Dooley > >> <conor+dt@kernel.org>; Mathieu Poirier <mathieu.poirier@linaro.org>; Bjorn > >> Andersson <andersson@kernel.org>; Konrad Dybcio > >> <konradybcio@kernel.org> > >> Cc: coresight@lists.linaro.org; linux-arm-kernel@lists.infradead.org; > >> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm- > >> msm@vger.kernel.org > >> Subject: Re: [PATCH v6 2/2] coresight: Add label sysfs node support > >> > >> On 17/12/2024 06:33, Mao Jinlong wrote: > >>> For some coresight components like CTI and TPDM, there could be > >>> numerous of them. From the node name, we can only get the type and > >>> register address of the component. We can't identify the HW or the > >>> system the component belongs to. Add label sysfs node support for > >>> showing the intuitive name of the device. > >>> > >>> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> > >>> --- > >>> .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ > >>> .../sysfs-bus-coresight-devices-funnel | 6 ++++ > >>> .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ > >>> drivers/hwtracing/coresight/coresight-sysfs.c | 32 > >> +++++++++++++++++++ > >>> 4 files changed, 50 insertions(+) > >> > >> Do you think we need to name the devices using the label ? > >> > > > > No - absolutely not. If we use label to name devices then we have to validate that the string is a correctly formed device name and that it has not been previously used. > > Anything that doesn't contain '/' can be a device name ? And it is very > easy to find if the device name has been used in the coresight bus, > after all these devices only appear there. > > It is as good as : > > bus_find_device_by_name(coresight_bus_type, NULL, name) == NULL > > Of course with coresight_mutex() held. > > Suzuki > DTS label property (DT spec 4.1.2) is a freeform string, specified to be a human readable description of the device, e.g. :- cti0@0x1000 { reg = <0x1000>; label = "main system CTI"; }; Arguably the label is completely unnecessary - as the @0x1000 tells the knowledgeable user, with a hardware specification of the device precisely what this CTI does and is related to. The point of this patchset is to add context to the name@addr to make the identification of the devices easier. The DT compiler should ensure that the device tree is well formed. Using driver selected names (cti_cpu0 ... etc) guarantees that every device found in the DT has a unique representation in sysfs. Once a freeform string is used, then not only are duplicates possible, illegal device names are possible, all of which can result in missing nodes or worse. This requires handling / complications that are unnecessary for the purpose. Yes of course it is easy to look for duplicate names, reject bad ones, emit errors - but that could end up with a partially working system with missing components. Why add potential for breakage when it is not necessary? Regards Mike > > > > > Using the canonical driver selected names works best as we are guaranteed a unique name and the information label can be used to provide flexible context information that best matches the users requirements. > > > > Mike > > > >> Or is this enough ? > > > >> Suzuki > >> > >> > >>> > >>> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >>> index bf2869c413e7..909670e0451a 100644 > >>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti > >>> @@ -239,3 +239,9 @@ Date: March 2020 > >>> KernelVersion 5.7 > >>> Contact: Mike Leach or Mathieu Poirier > >>> Description: (Write) Clear all channel / trigger programming. > >>> + > >>> +What: /sys/bus/coresight/devices/<cti-name>/label > >>> +Date: Dec 2024 > >>> +KernelVersion 6.14 > >>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > >>> +Description: (Read) Show hardware context information of device. > >>> diff --git > >>> a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > >>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > >>> index d75acda5e1b3..944aad879aeb 100644 > >>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > >>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel > >>> @@ -10,3 +10,9 @@ Date: November 2014 > >>> KernelVersion: 3.19 > >>> Contact: Mathieu Poirier <mathieu.poirier@linaro.org> > >>> Description: (RW) Defines input port priority order. > >>> + > >>> +What: /sys/bus/coresight/devices/<memory_map>.funnel/label > >>> +Date: Dec 2024 > >>> +KernelVersion 6.14 > >>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > >>> +Description: (Read) Show hardware context information of device. > >>> diff --git > >>> a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > >>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > >>> index bf710ea6e0ef..309802246398 100644 > >>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > >>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm > >>> @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) > >> <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t > >>> Description: > >>> (RW) Set/Get the MSR(mux select register) for the CMB > >> subunit > >>> TPDM. > >>> + > >>> +What: /sys/bus/coresight/devices/<tpdm-name>/label > >>> +Date: Dec 2024 > >>> +KernelVersion 6.14 > >>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> > >>> +Description: (Read) Show hardware context information of device. > >>> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c > >>> b/drivers/hwtracing/coresight/coresight-sysfs.c > >>> index a01c9e54e2ed..4af40cd7d75a 100644 > >>> --- a/drivers/hwtracing/coresight/coresight-sysfs.c > >>> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c > >>> @@ -7,6 +7,7 @@ > >>> #include <linux/device.h> > >>> #include <linux/idr.h> > >>> #include <linux/kernel.h> > >>> +#include <linux/property.h> > >>> > >>> #include "coresight-priv.h" > >>> #include "coresight-trace-id.h" > >>> @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device > >> *dev, > >>> } > >>> static DEVICE_ATTR_RW(enable_source); > >>> > >>> +static ssize_t label_show(struct device *dev, > >>> + struct device_attribute *attr, char *buf) { > >>> + > >>> + const char *str; > >>> + int ret = 0; > >>> + > >>> + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); > >>> + if (ret == 0) > >>> + return scnprintf(buf, PAGE_SIZE, "%s\n", str); > >>> + else > >>> + return ret; > >>> +} > >>> +static DEVICE_ATTR_RO(label); > >>> + > >>> static struct attribute *coresight_sink_attrs[] = { > >>> &dev_attr_enable_sink.attr, > >>> + &dev_attr_label.attr, > >>> NULL, > >>> }; > >>> ATTRIBUTE_GROUPS(coresight_sink); > >>> > >>> static struct attribute *coresight_source_attrs[] = { > >>> &dev_attr_enable_source.attr, > >>> + &dev_attr_label.attr, > >>> NULL, > >>> }; > >>> ATTRIBUTE_GROUPS(coresight_source); > >>> > >>> +static struct attribute *coresight_link_attrs[] = { > >>> + &dev_attr_label.attr, > >>> + NULL, > >>> +}; > >>> +ATTRIBUTE_GROUPS(coresight_link); > >>> + > >>> +static struct attribute *coresight_helper_attrs[] = { > >>> + &dev_attr_label.attr, > >>> + NULL, > >>> +}; > >>> +ATTRIBUTE_GROUPS(coresight_helper); > >>> + > >>> const struct device_type coresight_dev_type[] = { > >>> [CORESIGHT_DEV_TYPE_SINK] = { > >>> .name = "sink", > >>> @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { > >>> }, > >>> [CORESIGHT_DEV_TYPE_LINK] = { > >>> .name = "link", > >>> + .groups = coresight_link_groups, > >>> }, > >>> [CORESIGHT_DEV_TYPE_LINKSINK] = { > >>> .name = "linksink", > >>> @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { > >>> }, > >>> [CORESIGHT_DEV_TYPE_HELPER] = { > >>> .name = "helper", > >>> + .groups = coresight_helper_groups, > >>> } > >>> }; > >>> /* Ensure the enum matches the names and groups */ > >> > >> _______________________________________________ > >> CoreSight mailing list -- coresight@lists.linaro.org To unsubscribe send an > >> email to coresight-leave@lists.linaro.org >
On 18/12/2024 10:57, Jinlong Mao wrote: > > > On 2024/12/18 17:38, Suzuki K Poulose wrote: >> On 17/12/2024 06:33, Mao Jinlong wrote: >>> For some coresight components like CTI and TPDM, there could be >>> numerous of them. From the node name, we can only get the type and >>> register address of the component. We can't identify the HW or the >>> system the component belongs to. Add label sysfs node support for >>> showing the intuitive name of the device. >>> >>> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> >>> --- >>> .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ >>> .../sysfs-bus-coresight-devices-funnel | 6 ++++ >>> .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ >>> drivers/hwtracing/coresight/coresight-sysfs.c | 32 +++++++++++++++++++ >>> 4 files changed, 50 insertions(+) >> >> Do you think we need to name the devices using the label ? Or is this >> enough ? >> >> Suzuki > Hi Suzuki, > > In my opinion, we should use label as the device name. As Linux device driver name? No, that's not the point of label. We don't do such stuff, nowhere. Best regards, Krzysztof
On 19/12/2024 11:17, Mike Leach wrote: > Hi, > > On Wed, 18 Dec 2024 at 18:16, Suzuki K Poulose <suzuki.poulose@arm.com> wrote: >> >> Hi Mike >> >> On 18/12/2024 09:56, Mike Leach wrote: >>> Hi >>> >>>> -----Original Message----- >>>> From: Suzuki K Poulose <suzuki.poulose@arm.com> >>>> Sent: Wednesday, December 18, 2024 9:38 AM >>>> To: Mao Jinlong <quic_jinlmao@quicinc.com>; Mike Leach >>>> <mike.leach@linaro.org>; James Clark <James.Clark@arm.com>; Rob Herring >>>> <robh@kernel.org>; Krzysztof Kozlowski <krzk+dt@kernel.org>; Conor Dooley >>>> <conor+dt@kernel.org>; Mathieu Poirier <mathieu.poirier@linaro.org>; Bjorn >>>> Andersson <andersson@kernel.org>; Konrad Dybcio >>>> <konradybcio@kernel.org> >>>> Cc: coresight@lists.linaro.org; linux-arm-kernel@lists.infradead.org; >>>> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; linux-arm- >>>> msm@vger.kernel.org >>>> Subject: Re: [PATCH v6 2/2] coresight: Add label sysfs node support >>>> >>>> On 17/12/2024 06:33, Mao Jinlong wrote: >>>>> For some coresight components like CTI and TPDM, there could be >>>>> numerous of them. From the node name, we can only get the type and >>>>> register address of the component. We can't identify the HW or the >>>>> system the component belongs to. Add label sysfs node support for >>>>> showing the intuitive name of the device. >>>>> >>>>> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> >>>>> --- >>>>> .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ >>>>> .../sysfs-bus-coresight-devices-funnel | 6 ++++ >>>>> .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ >>>>> drivers/hwtracing/coresight/coresight-sysfs.c | 32 >>>> +++++++++++++++++++ >>>>> 4 files changed, 50 insertions(+) >>>> >>>> Do you think we need to name the devices using the label ? >>>> >>> >>> No - absolutely not. If we use label to name devices then we have to validate that the string is a correctly formed device name and that it has not been previously used. >> >> Anything that doesn't contain '/' can be a device name ? And it is very >> easy to find if the device name has been used in the coresight bus, >> after all these devices only appear there. >> >> It is as good as : >> >> bus_find_device_by_name(coresight_bus_type, NULL, name) == NULL >> >> Of course with coresight_mutex() held. >> >> Suzuki >> > > DTS label property (DT spec 4.1.2) is a freeform string, specified to > be a human readable description of the device, e.g. :- > > cti0@0x1000 { > reg = <0x1000>; > label = "main system CTI"; > }; > > Arguably the label is completely unnecessary - as the @0x1000 tells > the knowledgeable user, with a hardware specification of the device > precisely what this CTI does and is related to. > > The point of this patchset is to add context to the name@addr to make > the identification of the devices easier. > > The DT compiler should ensure that the device tree is well formed. > Using driver selected names (cti_cpu0 ... etc) guarantees that every > device found in the DT has a unique representation in sysfs. > > Once a freeform string is used, then not only are duplicates possible, > illegal device names are possible, all of which can result in missing > nodes or worse. This requires handling / complications that are > unnecessary for the purpose. > > Yes of course it is easy to look for duplicate names, reject bad ones, > emit errors - but that could end up with a partially working system > with missing components. > > Why add potential for breakage when it is not necessary? Fair enough, we can do away with exporting the label. Cheers Suzuki > > Regards > > Mike > >> >>> >>> Using the canonical driver selected names works best as we are guaranteed a unique name and the information label can be used to provide flexible context information that best matches the users requirements. >>> >>> Mike >>> >>>> Or is this enough ? >>> >>>> Suzuki >>>> >>>> >>>>> >>>>> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>>>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>>>> index bf2869c413e7..909670e0451a 100644 >>>>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>>>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti >>>>> @@ -239,3 +239,9 @@ Date: March 2020 >>>>> KernelVersion 5.7 >>>>> Contact: Mike Leach or Mathieu Poirier >>>>> Description: (Write) Clear all channel / trigger programming. >>>>> + >>>>> +What: /sys/bus/coresight/devices/<cti-name>/label >>>>> +Date: Dec 2024 >>>>> +KernelVersion 6.14 >>>>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >>>>> +Description: (Read) Show hardware context information of device. >>>>> diff --git >>>>> a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>>>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>>>> index d75acda5e1b3..944aad879aeb 100644 >>>>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>>>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel >>>>> @@ -10,3 +10,9 @@ Date: November 2014 >>>>> KernelVersion: 3.19 >>>>> Contact: Mathieu Poirier <mathieu.poirier@linaro.org> >>>>> Description: (RW) Defines input port priority order. >>>>> + >>>>> +What: /sys/bus/coresight/devices/<memory_map>.funnel/label >>>>> +Date: Dec 2024 >>>>> +KernelVersion 6.14 >>>>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >>>>> +Description: (Read) Show hardware context information of device. >>>>> diff --git >>>>> a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>>>> b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>>>> index bf710ea6e0ef..309802246398 100644 >>>>> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>>>> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm >>>>> @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) >>>> <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t >>>>> Description: >>>>> (RW) Set/Get the MSR(mux select register) for the CMB >>>> subunit >>>>> TPDM. >>>>> + >>>>> +What: /sys/bus/coresight/devices/<tpdm-name>/label >>>>> +Date: Dec 2024 >>>>> +KernelVersion 6.14 >>>>> +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> >>>>> +Description: (Read) Show hardware context information of device. >>>>> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c >>>>> b/drivers/hwtracing/coresight/coresight-sysfs.c >>>>> index a01c9e54e2ed..4af40cd7d75a 100644 >>>>> --- a/drivers/hwtracing/coresight/coresight-sysfs.c >>>>> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c >>>>> @@ -7,6 +7,7 @@ >>>>> #include <linux/device.h> >>>>> #include <linux/idr.h> >>>>> #include <linux/kernel.h> >>>>> +#include <linux/property.h> >>>>> >>>>> #include "coresight-priv.h" >>>>> #include "coresight-trace-id.h" >>>>> @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device >>>> *dev, >>>>> } >>>>> static DEVICE_ATTR_RW(enable_source); >>>>> >>>>> +static ssize_t label_show(struct device *dev, >>>>> + struct device_attribute *attr, char *buf) { >>>>> + >>>>> + const char *str; >>>>> + int ret = 0; >>>>> + >>>>> + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); >>>>> + if (ret == 0) >>>>> + return scnprintf(buf, PAGE_SIZE, "%s\n", str); >>>>> + else >>>>> + return ret; >>>>> +} >>>>> +static DEVICE_ATTR_RO(label); >>>>> + >>>>> static struct attribute *coresight_sink_attrs[] = { >>>>> &dev_attr_enable_sink.attr, >>>>> + &dev_attr_label.attr, >>>>> NULL, >>>>> }; >>>>> ATTRIBUTE_GROUPS(coresight_sink); >>>>> >>>>> static struct attribute *coresight_source_attrs[] = { >>>>> &dev_attr_enable_source.attr, >>>>> + &dev_attr_label.attr, >>>>> NULL, >>>>> }; >>>>> ATTRIBUTE_GROUPS(coresight_source); >>>>> >>>>> +static struct attribute *coresight_link_attrs[] = { >>>>> + &dev_attr_label.attr, >>>>> + NULL, >>>>> +}; >>>>> +ATTRIBUTE_GROUPS(coresight_link); >>>>> + >>>>> +static struct attribute *coresight_helper_attrs[] = { >>>>> + &dev_attr_label.attr, >>>>> + NULL, >>>>> +}; >>>>> +ATTRIBUTE_GROUPS(coresight_helper); >>>>> + >>>>> const struct device_type coresight_dev_type[] = { >>>>> [CORESIGHT_DEV_TYPE_SINK] = { >>>>> .name = "sink", >>>>> @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { >>>>> }, >>>>> [CORESIGHT_DEV_TYPE_LINK] = { >>>>> .name = "link", >>>>> + .groups = coresight_link_groups, >>>>> }, >>>>> [CORESIGHT_DEV_TYPE_LINKSINK] = { >>>>> .name = "linksink", >>>>> @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { >>>>> }, >>>>> [CORESIGHT_DEV_TYPE_HELPER] = { >>>>> .name = "helper", >>>>> + .groups = coresight_helper_groups, >>>>> } >>>>> }; >>>>> /* Ensure the enum matches the names and groups */ >>>> >>>> _______________________________________________ >>>> CoreSight mailing list -- coresight@lists.linaro.org To unsubscribe send an >>>> email to coresight-leave@lists.linaro.org >> > >
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti index bf2869c413e7..909670e0451a 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-cti @@ -239,3 +239,9 @@ Date: March 2020 KernelVersion 5.7 Contact: Mike Leach or Mathieu Poirier Description: (Write) Clear all channel / trigger programming. + +What: /sys/bus/coresight/devices/<cti-name>/label +Date: Dec 2024 +KernelVersion 6.14 +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel index d75acda5e1b3..944aad879aeb 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-funnel @@ -10,3 +10,9 @@ Date: November 2014 KernelVersion: 3.19 Contact: Mathieu Poirier <mathieu.poirier@linaro.org> Description: (RW) Defines input port priority order. + +What: /sys/bus/coresight/devices/<memory_map>.funnel/label +Date: Dec 2024 +KernelVersion 6.14 +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> +Description: (Read) Show hardware context information of device. diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm index bf710ea6e0ef..309802246398 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm @@ -257,3 +257,9 @@ Contact: Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_t Description: (RW) Set/Get the MSR(mux select register) for the CMB subunit TPDM. + +What: /sys/bus/coresight/devices/<tpdm-name>/label +Date: Dec 2024 +KernelVersion 6.14 +Contact: Mao Jinlong <quic_jinlmao@quicinc.com> +Description: (Read) Show hardware context information of device. diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index a01c9e54e2ed..4af40cd7d75a 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -7,6 +7,7 @@ #include <linux/device.h> #include <linux/idr.h> #include <linux/kernel.h> +#include <linux/property.h> #include "coresight-priv.h" #include "coresight-trace-id.h" @@ -366,18 +367,47 @@ static ssize_t enable_source_store(struct device *dev, } static DEVICE_ATTR_RW(enable_source); +static ssize_t label_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + + const char *str; + int ret = 0; + + ret = fwnode_property_read_string(dev_fwnode(dev), "label", &str); + if (ret == 0) + return scnprintf(buf, PAGE_SIZE, "%s\n", str); + else + return ret; +} +static DEVICE_ATTR_RO(label); + static struct attribute *coresight_sink_attrs[] = { &dev_attr_enable_sink.attr, + &dev_attr_label.attr, NULL, }; ATTRIBUTE_GROUPS(coresight_sink); static struct attribute *coresight_source_attrs[] = { &dev_attr_enable_source.attr, + &dev_attr_label.attr, NULL, }; ATTRIBUTE_GROUPS(coresight_source); +static struct attribute *coresight_link_attrs[] = { + &dev_attr_label.attr, + NULL, +}; +ATTRIBUTE_GROUPS(coresight_link); + +static struct attribute *coresight_helper_attrs[] = { + &dev_attr_label.attr, + NULL, +}; +ATTRIBUTE_GROUPS(coresight_helper); + const struct device_type coresight_dev_type[] = { [CORESIGHT_DEV_TYPE_SINK] = { .name = "sink", @@ -385,6 +415,7 @@ const struct device_type coresight_dev_type[] = { }, [CORESIGHT_DEV_TYPE_LINK] = { .name = "link", + .groups = coresight_link_groups, }, [CORESIGHT_DEV_TYPE_LINKSINK] = { .name = "linksink", @@ -396,6 +427,7 @@ const struct device_type coresight_dev_type[] = { }, [CORESIGHT_DEV_TYPE_HELPER] = { .name = "helper", + .groups = coresight_helper_groups, } }; /* Ensure the enum matches the names and groups */
For some coresight components like CTI and TPDM, there could be numerous of them. From the node name, we can only get the type and register address of the component. We can't identify the HW or the system the component belongs to. Add label sysfs node support for showing the intuitive name of the device. Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> --- .../testing/sysfs-bus-coresight-devices-cti | 6 ++++ .../sysfs-bus-coresight-devices-funnel | 6 ++++ .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++++ drivers/hwtracing/coresight/coresight-sysfs.c | 32 +++++++++++++++++++ 4 files changed, 50 insertions(+)