Hi Mathieu,

On Thu, 18 Feb 2021 at 23:52, Mathieu Poirier mathieu.poirier@linaro.org wrote:

On Thu, Jan 28, 2021 at 05:09:27PM +0000, Mike Leach wrote:

...

Creates an system management API to allow complex configurations and features to be programmed into a CoreSight infrastructure.

A feature is defined as a programming set for a device or class of devices.

A configuration is a set of features across the system that are enabled for a trace session.

The API will manage system wide configuration, and allow complex programmed features to be added to individual device instances, and provide for system wide configuration selection on trace capture operations.

This patch creates the initial data object and the initial API for loading configurations and features.

Signed-off-by: Mike Leach mike.leach@linaro.org

drivers/hwtracing/coresight/Makefile | 2 +- .../hwtracing/coresight/coresight-config.h | 167 +++++++++++++++ drivers/hwtracing/coresight/coresight-core.c | 12 +- .../hwtracing/coresight/coresight-etm-perf.c | 2 +- .../hwtracing/coresight/coresight-etm-perf.h | 2 +- .../hwtracing/coresight/coresight-syscfg.c | 197 ++++++++++++++++++ .../hwtracing/coresight/coresight-syscfg.h | 54 +++++ 7 files changed, 432 insertions(+), 4 deletions(-) create mode 100644 drivers/hwtracing/coresight/coresight-config.h create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.c create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.h

diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index f20e357758d1..4ce854c434b1 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -4,7 +4,7 @@ # obj-$(CONFIG_CORESIGHT) += coresight.o coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \

•         coresight-sysfs.o
  

•         coresight-sysfs.o coresight-syscfg.o
  

obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \ coresight-tmc-etr.o diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h new file mode 100644 index 000000000000..3fedf8ab3cee --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -0,0 +1,167 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*

• • Copyright (c) 2020 Linaro Limited, All rights reserved.
• • Author: Mike Leach mike.leach@linaro.org
• */

+#ifndef _CORESIGHT_CORESIGHT_CONFIG_H +#define _CORESIGHT_CORESIGHT_CONFIG_H

+#include <linux/coresight.h> +#include <linux/types.h>

+/* CoreSight Configuration Management - component and system wide configuration */

+/*

• • Register type flags for register value descriptor:
• • describe how the value is interpreted, and handled.
• */

+#define CS_CFG_REG_TYPE_STD 0x80 /* reg is standard reg */ +#define CS_CFG_REG_TYPE_RESOURCE 0x40 /* reg is a resource */ +#define CS_CFG_REG_TYPE_VAL_PARAM 0x08 /* reg value uses param */ +#define CS_CFG_REG_TYPE_VAL_MASK 0x04 /* reg value bit masked */ +#define CS_CFG_REG_TYPE_VAL_64BIT 0x02 /* reg value 64 bit */ +#define CS_CFG_REG_TYPE_VAL_SAVE 0x01 /* reg value save on disable */

+/*

• • flags defining what device class a feature will match to when processing a
• • system configuration - used by config data and devices.
• */

+#define CS_CFG_MATCH_CLASS_SRC_ALL 0x0001 /* match any source */ +#define CS_CFG_MATCH_CLASS_SRC_ETM4 0x0002 /* match any ETMv4 device */

+/* flags defining device instance matching - used in config match desc data. */ +#define CS_CFG_MATCH_INST_ANY 0x80000000 /* any instance of a class */

+/*

• • Limit number of presets in a configuration
• • This is related to the number of bits (4) we use to select the preset on
• • the perf command line. Preset 0 is always none selected.
• • See PMU_FORMAT_ATTR(preset, "config:0-3") in coresight-etm-perf.c
• */

+#define CS_CFG_CONFIG_PRESET_MAX 15

+/**

• • Parameter descriptor for a device feature.
• • @name: Name of parameter.
• • @value: Initial or default value.
• */

+struct cscfg_parameter_desc {

• const char *name;
  

• u64 value;
  

+};

+/**

• • Representation of register value.
• • Supports full 64 bit register value, or 32 bit value with optional mask
• • value.
• • @type: define register usage and interpretation.
• • @offset: the address offset for register in the hardware device (per device specification).
• • @hw_info: optional hardware device type specific information. (ETM / CTI specific etc)
• • @val64: 64 bit value.
• • @val32: 32 bit value.
• • @mask32: 32 bit mask when using 32 bit value to access device register.
• */

+struct cscfg_regval_desc {

• struct {
  

•         u32 type:8;
  

•         u32 offset:12;
  

•         u32 hw_info:12;
  

• };
  

• union {
  

•         u64 val64;
  

•         struct {
  

•                 u32 val32;
  

•                 u32 mask32;
  

•         };
  

• };
  

+};

+/**

• • Device feature descriptor - combination of registers and parameters to
• • program a device to implement a specific complex function.
• • @name: feature name.
• • @brief: brief description of the feature.
• • @item: List entry.
• • @match_flags: matching information if loading into a device
• • @nr_params: number of parameters used.
• • @params: array of parameters used.
• • @nr_regs: number of registers used.
• • @reg: array of registers used.
• */

+struct cscfg_feature_desc {

• const char *name;
  

• const char *brief;
  

• struct list_head item;
  

• u32 match_flags;
  

• int nr_params;
  

• struct cscfg_parameter_desc *params;
  

• int nr_regs;
  

• struct cscfg_regval_desc *regs;
  

+};

+/**

• • Match descriptor - Device / feature matching when loading into devices
• • Used by loading configurations to define which class or specific devices
• • they want to match used features to, and registered devices to specify which
• • matching class and information they support.
• • The load process uses these matching pairs to load feature instances into
• • matching devices.
• • @match_flags: used to match to a particular class of device.
• */

+struct cscfg_match_desc {

• u32 match_flags;
  

+};

+/**

• • Descriptor for features referenced by a configuration.
• • @name: name of feature to use. Match against the @name in struct

• •       cscfg_feature_desc.
    

• • @match: match info for the feature when used in this configuration -

• •       may be all devices of a class or a specific device in that class.
    

• */

+struct cscfg_config_feat_ref {

• const char *name;
  

• struct cscfg_match_desc match;
  

I would get rid of structure cscfg_match_desc and put @match_flags right here.

How often do you envision features having different matches for different configuration? If there is no real use for it we could use @name and @match_flags from structure cscfg_feature_desck and get rid of cscfg_config_feat_ref entirely.

I've been giving this some consideration - features really need the match flags - they ensure hardware compatibility. Configs - a simple select by name should be sufficient. Both will need the ability to match to specific devices - e.g. a system CTI will be connected differently than all the standard "cpu" CTIs, but this can be acheived for configurations at least by way of extending the naming - e.g. "feature" selects the feature on any device that supports it, "feature.device" selects the feature on a specific device. So yes - we can drop cscfg_config_feat_ref and probably cscfg_match_desc as the match info will only appear in the feature_desc.

...

+};

+/**

• • Configuration descriptor - describes selectable system configuration.
• • A configuration describes device features in use, and may provide preset
• • values for the parameters in those features.
• • A single set of presets is the sum of the parameters declared by
• • all the features in use - this value is @nr_total_params.
• • @name: name of the configuration - used for selection.
• • @brief: description of the purpose of the configuration.
• • @item: list entry.
• • @nr_refs: Number of features used in this configuration.
• • @refs: references to features used in this configuration..
• • @nr_presets: Number of sets of presets supplied by this configuration.
• • @nr_total_params: Sum of all parameters declared by used features
• • @presets: Array of preset values.
• */

+struct cscfg_config_desc {

• const char *name;
  

• const char *brief;
  

• struct list_head item;
  

• int nr_refs;
  

• struct cscfg_config_feat_ref *refs;
  

• int nr_presets;
  

• int nr_total_params;
  

• const u64 *presets; /* nr_presets * nr_total_params */
  

+};

+#endif /* _CORESIGHT_CORESIGHT_CONFIG_H */ diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 0062c8935653..6bd41de46648 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -21,6 +21,7 @@

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

static DEFINE_MUTEX(coresight_mutex);

@@ -1739,13 +1740,22 @@ static int __init coresight_init(void)

  ret = etm_perf_init();
  if (ret)

•         bus_unregister(&coresight_bustype);
  

•         goto exit_bus_unregister;
  
  

• /* initialise the coresight syscfg API */
  

• ret = cscfg_init();
  

• if (!ret)
  

•         return 0;
  

• etm_perf_exit();
  

+exit_bus_unregister:

• bus_unregister(&coresight_bustype);
  return ret;
  

}

static void __exit coresight_exit(void) {

• cscfg_exit();
  etm_perf_exit();
  bus_unregister(&coresight_bustype);
  

} diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index bdc34ca449f7..a608081bd446 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -627,7 +627,7 @@ int __init etm_perf_init(void) return ret; }

-void __exit etm_perf_exit(void) +void etm_perf_exit(void) { perf_pmu_unregister(&etm_pmu); }

Ok

...

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h index 3e4f2ad5e193..29d90dfeba31 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.h +++ b/drivers/hwtracing/coresight/coresight-etm-perf.h @@ -83,6 +83,6 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle) #endif /* CONFIG_CORESIGHT */

int __init etm_perf_init(void); -void __exit etm_perf_exit(void); +void etm_perf_exit(void);

Ok

...

#endif diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c new file mode 100644 index 000000000000..f7e396a5f9cb --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Copyright (c) 2020 Linaro Limited, All rights reserved.
• • Author: Mike Leach mike.leach@linaro.org
• */

+#include <linux/platform_device.h>

+#include "coresight-config.h" +#include "coresight-syscfg.h"

+/*

• • cscfg_ API manages configurations and features for the entire coresight
• • infrastructure.
• • It allows the loading of configurations and features, and loads these into
• • coresight devices as appropriate.
• */

+/* protect the cscsg_data and device */ +static DEFINE_MUTEX(cscfg_mutex);

+/* only one of these */ +static struct cscfg_manager *cscfg_mgr;

+/* load features and configuations into the lists */

+/* check feature list for a named feature - call with mutex locked. */ +static bool cscfg_match_list_feat(const char *name) +{

• struct cscfg_feature_desc *curr_item;
  

• list_for_each_entry(curr_item, &cscfg_mgr->data.feat_desc_list, item) {
  

•         if (strcmp(curr_item->name, name) == 0)
  

•                 return true;
  

• }
  

• return false;
  

+}

+/* check all feat needed for cfg are in the list - call with mutex locked. */ +static int cscfg_check_feat_for_cfg(struct cscfg_config_desc *cfg_desc) +{

• int i;
  

• for (i = 0; i < cfg_desc->nr_refs; i++)
  

•         if (!cscfg_match_list_feat(cfg_desc->refs[i].name))
  

•                 return -EINVAL;
  

• return 0;
  

+}

+/*

• • load feature - add to feature list.
• */

+static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc) +{

• list_add(&feat_desc->item, &cscfg_mgr->data.feat_desc_list);
  

• return 0;
  

+}

+/*

• • load config into the system - validate used features exist then add to
• • config list.
• */

+static int cscfg_load_config(struct cscfg_config_desc *cfg_desc) +{

• int err;
  

• /* validate features are present */
  

• err = cscfg_check_feat_for_cfg(cfg_desc);
  

• if (err)
  

•         return err;
  

• list_add(&cfg_desc->item, &cscfg_mgr->data.config_desc_list);
  

• return 0;
  

+}

+/*

• • External API function to load feature and config sets.
• • Take a 0 terminated array of feature descriptors and/or configuration
• • descriptors and load into the system.
• • Features are loaded first to ensure configuration dependencies can be met.
• */

+int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,

•                    struct cscfg_feature_desc **feat_descs)
  

+{

• int err, i = 0;
  

• mutex_lock(&cscfg_mutex);
  

• /* load features first */
  

• if (feat_descs) {
  

•         while (feat_descs[i]) {
  

•                 err = cscfg_load_feat(feat_descs[i]);
  

•                 if (err) {
  

•                         pr_err("coresight-syscfg: Failed to load feature %s\n",
  

•                                feat_descs[i]->name);
  

•                         goto do_unlock;
  

•                 }
  

•                 i++;
  

•         }
  

• }
  

• /* next any configurations to check feature dependencies */
  

• i = 0;
  

• if (cfg_descs) {
  

•         while (cfg_descs[i]) {
  

•                 err = cscfg_load_config(cfg_descs[i]);
  

•                 if (err) {
  

•                         pr_err("coresight-syscfg: Failed to load configuration %s\n",
  

•                                cfg_descs[i]->name);
  

•                         goto do_unlock;
  

•                 }
  

•                 i++;
  

•         }
  

• }
  

+do_unlock:

• mutex_unlock(&cscfg_mutex);
  

• return err;
  

+} +EXPORT_SYMBOL_GPL(cscfg_load_config_sets);

+/* Initialise system configuration management device. */

+struct device *to_device_cscfg(void) +{

• return cscfg_mgr ? &cscfg_mgr->dev : NULL;
  

+}

+/* Must have a release function or the kernel will complain on module unload */ +void cscfg_dev_release(struct device *dev) +{

• kfree(cscfg_mgr);
  

• cscfg_mgr = NULL;
  

+}

+/* a device is needed to "own" some kernel elements such as sysfs entries. */ +int cscfg_create_device(void) +{

• struct device *dev;
  

• int err = -ENOMEM;
  

• mutex_lock(&cscfg_mutex);
  

• if (cscfg_mgr) {
  

•         err = -EINVAL;
  

•         goto create_dev_exit_unlock;
  

• }
  

• cscfg_mgr = kzalloc(sizeof(struct cscfg_manager), GFP_KERNEL);
  

• if (!cscfg_mgr)
  

•         goto create_dev_exit_unlock;
  

• /* setup the device */
  

• dev = to_device_cscfg();
  

• dev->release = cscfg_dev_release;
  

• dev->init_name = "system_cfg";
  

• err = device_register(dev);
  

• if (err)
  

•         cscfg_dev_release(dev);
  

+create_dev_exit_unlock:

• mutex_unlock(&cscfg_mutex);
  

• return err;
  

+}

Much cleaner

...

+void cscfg_clear_device(void) +{

• mutex_lock(&cscfg_mutex);
  

• device_unregister(to_device_cscfg());
  

• mutex_unlock(&cscfg_mutex);
  

+}

+/* Initialise system config management API device */ +int __init cscfg_init(void) +{

• int err = 0;
  

• err = cscfg_create_device();
  

• if (err)
  

•         return err;
  

• INIT_LIST_HEAD(&cscfg_mgr->data.csdev_desc_list);
  

• INIT_LIST_HEAD(&cscfg_mgr->data.feat_desc_list);
  

• INIT_LIST_HEAD(&cscfg_mgr->data.config_desc_list);
  

• cscfg_mgr->data.nr_csdev = 0;
  

We are keeping track of the number of cs devices registered with the manager but I don't see a place (in this patchset) where the information is used. If indeed we dont' need it I suggest moving the lists held in cscfg_api_data directly to cscfg_manager.

No the count can be dropped. Its a hangover from some previously dropped design feature. Now we have the manager object, there is no value in the separate data object. I'll subsume the lists and other things that end up in this sturcture directly into the manager.

...

• dev_info(to_device_cscfg(), "CoreSight Configuration manager initialised");
  

• return 0;
  

+}

+void __exit cscfg_exit(void) +{

• cscfg_clear_device();
  

+} diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h new file mode 100644 index 000000000000..907ba8d3efea --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/*

• • Coresight system configuration driver.
• */

+#ifndef CORESIGHT_SYSCFG_H +#define CORESIGHT_SYSCFG_H

+#include <linux/coresight.h> +#include <linux/device.h>

+#include "coresight-config.h"

+/**

• • System configuration manager API data.
• • @csdev_list: List of coresight devices registered with the configuration manager.
• • @feat_desc_list: List of feature descriptors to load into registered devices.
• • @config_desc_list: List of system configuration descriptors to load into registered devices.
• • @nr_csdev: Number of registered devices with the cscfg system
• */

+struct cscfg_api_data {

• struct list_head csdev_desc_list;
  

• struct list_head feat_desc_list;
  

• struct list_head config_desc_list;
  

• int nr_csdev;
  

+};

+/* internal core operations for cscfg */ +int __init cscfg_init(void); +void __exit cscfg_exit(void);

+/* syscfg manager external API */ +int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,

•                    struct cscfg_feature_desc **feat_descs);
  

+/**

• • System configuration manager device.
• • Need a device to 'own' some coresight system wide sysfs entries in
• • perf events, configfs etc.
• • @dev: The device.
• • @data: The API data.
• */

+struct cscfg_manager {

• struct device dev;
  

• struct cscfg_api_data data;
  

+};

+/* get reference to dev in cscfg_manager */ +struct device *to_device_cscfg(void);

This patch looks really good now. More comments to come tomorrow.

Thanks, Mathieu

...

+#endif /* CORESIGHT_SYSCFG_H */

2.17.1

Thanks for the review

Mike

Hi Mathieu,

On Mon, 22 Feb 2021 at 18:50, Mathieu Poirier mathieu.poirier@linaro.org wrote:

On Thu, Jan 28, 2021 at 05:09:27PM +0000, Mike Leach wrote:

...

Creates an system management API to allow complex configurations and features to be programmed into a CoreSight infrastructure.

A feature is defined as a programming set for a device or class of devices.

A configuration is a set of features across the system that are enabled for a trace session.

The API will manage system wide configuration, and allow complex programmed features to be added to individual device instances, and provide for system wide configuration selection on trace capture operations.

This patch creates the initial data object and the initial API for loading configurations and features.

Signed-off-by: Mike Leach mike.leach@linaro.org

drivers/hwtracing/coresight/Makefile | 2 +- .../hwtracing/coresight/coresight-config.h | 167 +++++++++++++++ drivers/hwtracing/coresight/coresight-core.c | 12 +- .../hwtracing/coresight/coresight-etm-perf.c | 2 +- .../hwtracing/coresight/coresight-etm-perf.h | 2 +- .../hwtracing/coresight/coresight-syscfg.c | 197 ++++++++++++++++++ .../hwtracing/coresight/coresight-syscfg.h | 54 +++++ 7 files changed, 432 insertions(+), 4 deletions(-) create mode 100644 drivers/hwtracing/coresight/coresight-config.h create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.c create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.h

diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index f20e357758d1..4ce854c434b1 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -4,7 +4,7 @@ # obj-$(CONFIG_CORESIGHT) += coresight.o coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \

•         coresight-sysfs.o
  

•         coresight-sysfs.o coresight-syscfg.o
  

obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \ coresight-tmc-etr.o diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h new file mode 100644 index 000000000000..3fedf8ab3cee --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -0,0 +1,167 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*

• • Copyright (c) 2020 Linaro Limited, All rights reserved.
• • Author: Mike Leach mike.leach@linaro.org
• */

+#ifndef _CORESIGHT_CORESIGHT_CONFIG_H +#define _CORESIGHT_CORESIGHT_CONFIG_H

+#include <linux/coresight.h> +#include <linux/types.h>

+/* CoreSight Configuration Management - component and system wide configuration */

+/*

• • Register type flags for register value descriptor:
• • describe how the value is interpreted, and handled.
• */

+#define CS_CFG_REG_TYPE_STD 0x80 /* reg is standard reg */ +#define CS_CFG_REG_TYPE_RESOURCE 0x40 /* reg is a resource */ +#define CS_CFG_REG_TYPE_VAL_PARAM 0x08 /* reg value uses param */ +#define CS_CFG_REG_TYPE_VAL_MASK 0x04 /* reg value bit masked */ +#define CS_CFG_REG_TYPE_VAL_64BIT 0x02 /* reg value 64 bit */ +#define CS_CFG_REG_TYPE_VAL_SAVE 0x01 /* reg value save on disable */

+/*

• • flags defining what device class a feature will match to when processing a
• • system configuration - used by config data and devices.
• */

+#define CS_CFG_MATCH_CLASS_SRC_ALL 0x0001 /* match any source */ +#define CS_CFG_MATCH_CLASS_SRC_ETM4 0x0002 /* match any ETMv4 device */

+/* flags defining device instance matching - used in config match desc data. */ +#define CS_CFG_MATCH_INST_ANY 0x80000000 /* any instance of a class */

+/*

• • Limit number of presets in a configuration
• • This is related to the number of bits (4) we use to select the preset on
• • the perf command line. Preset 0 is always none selected.
• • See PMU_FORMAT_ATTR(preset, "config:0-3") in coresight-etm-perf.c
• */

+#define CS_CFG_CONFIG_PRESET_MAX 15

+/**

• • Parameter descriptor for a device feature.
• • @name: Name of parameter.
• • @value: Initial or default value.
• */

+struct cscfg_parameter_desc {

• const char *name;
  

• u64 value;
  

+};

+/**

• • Representation of register value.
• • Supports full 64 bit register value, or 32 bit value with optional mask
• • value.
• • @type: define register usage and interpretation.
• • @offset: the address offset for register in the hardware device (per device specification).
• • @hw_info: optional hardware device type specific information. (ETM / CTI specific etc)
• • @val64: 64 bit value.
• • @val32: 32 bit value.
• • @mask32: 32 bit mask when using 32 bit value to access device register.
• */

+struct cscfg_regval_desc {

• struct {
  

•         u32 type:8;
  

•         u32 offset:12;
  

•         u32 hw_info:12;
  

• };
  

• union {
  

•         u64 val64;
  

•         struct {
  

•                 u32 val32;
  

•                 u32 mask32;
  

•         };
  

• };
  

+};

+/**

• • Device feature descriptor - combination of registers and parameters to
• • program a device to implement a specific complex function.
• • @name: feature name.
• • @brief: brief description of the feature.
• • @item: List entry.
• • @match_flags: matching information if loading into a device
• • @nr_params: number of parameters used.
• • @params: array of parameters used.
• • @nr_regs: number of registers used.
• • @reg: array of registers used.
• */

+struct cscfg_feature_desc {

• const char *name;
  

• const char *brief;
  

• struct list_head item;
  

• u32 match_flags;
  

• int nr_params;
  

• struct cscfg_parameter_desc *params;
  

    struct cscfg_parameter_desc *params_desc;

...

• int nr_regs;
  

• struct cscfg_regval_desc *regs;
  

    struct cscfg_regval_desc *regs_desc;

That way I know exactly what I'm looking at when I see something like the following in patch 03:

    reg_desc = &feat->desc->regs[i];

Agreed - I'll improve the naming consistency in the next revision

Mike

Hi Suzuki,

On Wed, 3 Mar 2021 at 10:09, Suzuki K Poulose suzuki.poulose@arm.com wrote:

On 1/28/21 5:09 PM, Mike Leach wrote:

...

Creates an system management API to allow complex configurations and features to be programmed into a CoreSight infrastructure.

A feature is defined as a programming set for a device or class of devices.

A configuration is a set of features across the system that are enabled for a trace session.

The API will manage system wide configuration, and allow complex programmed features to be added to individual device instances, and provide for system wide configuration selection on trace capture operations.

This patch creates the initial data object and the initial API for loading configurations and features.

Signed-off-by: Mike Leach mike.leach@linaro.org

drivers/hwtracing/coresight/Makefile | 2 +- .../hwtracing/coresight/coresight-config.h | 167 +++++++++++++++ drivers/hwtracing/coresight/coresight-core.c | 12 +- .../hwtracing/coresight/coresight-etm-perf.c | 2 +- .../hwtracing/coresight/coresight-etm-perf.h | 2 +- .../hwtracing/coresight/coresight-syscfg.c | 197 ++++++++++++++++++ .../hwtracing/coresight/coresight-syscfg.h | 54 +++++ 7 files changed, 432 insertions(+), 4 deletions(-) create mode 100644 drivers/hwtracing/coresight/coresight-config.h create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.c create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.h

diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index f20e357758d1..4ce854c434b1 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -4,7 +4,7 @@ # obj-$(CONFIG_CORESIGHT) += coresight.o coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \

•         coresight-sysfs.o
  

•         coresight-sysfs.o coresight-syscfg.o
  

  obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \ coresight-tmc-etr.o

diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h new file mode 100644 index 000000000000..3fedf8ab3cee --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -0,0 +1,167 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*

• • Copyright (c) 2020 Linaro Limited, All rights reserved.
• • Author: Mike Leach mike.leach@linaro.org
• */

+#ifndef _CORESIGHT_CORESIGHT_CONFIG_H +#define _CORESIGHT_CORESIGHT_CONFIG_H

+#include <linux/coresight.h> +#include <linux/types.h>

+/* CoreSight Configuration Management - component and system wide configuration */

+/*

• • Register type flags for register value descriptor:
• • describe how the value is interpreted, and handled.
• */

+#define CS_CFG_REG_TYPE_STD 0x80 /* reg is standard reg */ +#define CS_CFG_REG_TYPE_RESOURCE 0x40 /* reg is a resource */ +#define CS_CFG_REG_TYPE_VAL_PARAM 0x08 /* reg value uses param */ +#define CS_CFG_REG_TYPE_VAL_MASK 0x04 /* reg value bit masked */ +#define CS_CFG_REG_TYPE_VAL_64BIT 0x02 /* reg value 64 bit */ +#define CS_CFG_REG_TYPE_VAL_SAVE 0x01 /* reg value save on disable */

+/*

• • flags defining what device class a feature will match to when processing a
• • system configuration - used by config data and devices.
• */

+#define CS_CFG_MATCH_CLASS_SRC_ALL 0x0001 /* match any source */

nit: spurious TAB instead of SPACE

...

+#define CS_CFG_MATCH_CLASS_SRC_ETM4 0x0002 /* match any ETMv4 device */

+/* flags defining device instance matching - used in config match desc data. */ +#define CS_CFG_MATCH_INST_ANY 0x80000000 /* any instance of a class */

+/*

• • Limit number of presets in a configuration
• • This is related to the number of bits (4) we use to select the preset on
• • the perf command line. Preset 0 is always none selected.
• • See PMU_FORMAT_ATTR(preset, "config:0-3") in coresight-etm-perf.c
• */

+#define CS_CFG_CONFIG_PRESET_MAX 15

+/**

• • Parameter descriptor for a device feature.
• • @name: Name of parameter.
• • @value: Initial or default value.
• */

+struct cscfg_parameter_desc {

• const char *name;
  

• u64 value;
  

+};

+/**

• • Representation of register value.
• • Supports full 64 bit register value, or 32 bit value with optional mask
• • value.
• • @type: define register usage and interpretation.
• • @offset: the address offset for register in the hardware device (per device specification).
• • @hw_info: optional hardware device type specific information. (ETM / CTI specific etc)
• • @val64: 64 bit value.
• • @val32: 32 bit value.
• • @mask32: 32 bit mask when using 32 bit value to access device register.
• */

+struct cscfg_regval_desc {

• struct {
  

•         u32 type:8;
  

•         u32 offset:12;
  

•         u32 hw_info:12;
  

• };
  

• union {
  

•         u64 val64;
  

•         struct {
  

•                 u32 val32;
  

•                 u32 mask32;
  

•         };
  

• };
  

+};

+/**

• • Device feature descriptor - combination of registers and parameters to
• • program a device to implement a specific complex function.
• • @name: feature name.
• • @brief: brief description of the feature.
• • @item: List entry.
• • @match_flags: matching information if loading into a device
• • @nr_params: number of parameters used.
• • @params: array of parameters used.
• • @nr_regs: number of registers used.
• • @reg: array of registers used.
• */

+struct cscfg_feature_desc {

• const char *name;
  

• const char *brief;
  

• struct list_head item;
  

• u32 match_flags;
  

Either we could use the cscfg_match_desc here or, simply follow inlining match_flags everywhere, below (e.g, cscfg_config_feat_ref)

Following Mathieus comments and a re-think on my part this will be addressed in the re-spin. I am planning to drop cfg_config_feat_ref in favour of mathing just by name in configs, and having discrete flags (and later named devices) in the feat_desc.

...

• int nr_params;
  

• struct cscfg_parameter_desc *params;scfg_config_feat_ref
  

• int nr_regs;
  

• struct cscfg_regval_desc *regs;
  

+};

+/**

• • Match descriptor - Device / feature matching when loading into devices
• • Used by loading configurations to define which class or specific devices
• • they want to match used features to, and registered devices to specify which
• • matching class and information they support.
• • The load process uses these matching pairs to load feature instances into
• • matching devices.
• • @match_flags: used to match to a particular class of device.
• */

+struct cscfg_match_desc {

• u32 match_flags;
  

+};

+/**

• • Descriptor for features referenced by a configuration.
• • @name: name of feature to use. Match against the @name in struct

• •       cscfg_feature_desc.
    

• • @match: match info for the feature when used in this configuration -

• •       may be all devices of a class or a specific device in that class.
    

• */

+struct cscfg_config_feat_ref {

• const char *name;
  

• struct cscfg_match_desc match;
  

+};

+/**

• • Configuration descriptor - describes selectable system configuration.
• • A configuration describes device features in use, and may provide preset
• • values for the parameters in those features.
• • A single set of presets is the sum of the parameters declared by
• • all the features in use - this value is @nr_total_params.
• • @name: name of the configuration - used for selection.
• • @brief: description of the purpose of the configuration.
• • @item: list entry.
• • @nr_refs: Number of features used in this configuration.
• • @refs: references to features used in this configuration..
• • @nr_presets: Number of sets of presets supplied by this configuration.
• • @nr_total_params: Sum of all parameters declared by used features
• • @presets: Array of preset values.
• */

+struct cscfg_config_desc {

• const char *name;
  

• const char *brief;
  

super nit: s/brief/desc ?

Probably 'description' to avoid clash with all the _desc names, but yes.

...

• struct list_head item;
  

• int nr_refs;
  

• struct cscfg_config_feat_ref *refs;
  

• int nr_presets;
  

• int nr_total_params;
  

• const u64 *presets; /* nr_presets * nr_total_params */
  

+};

+#endif /* _CORESIGHT_CORESIGHT_CONFIG_H */

...

diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c new file mode 100644 index 000000000000..f7e396a5f9cb --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Copyright (c) 2020 Linaro Limited, All rights reserved.
• • Author: Mike Leach mike.leach@linaro.org
• */

+#include <linux/platform_device.h>

+#include "coresight-config.h" +#include "coresight-syscfg.h"

+/*

• • cscfg_ API manages configurations and features for the entire coresight
• • infrastructure.
• • It allows the loading of configurations and features, and loads these into
• • coresight devices as appropriate.
• */

+/* protect the cscsg_data and device */ +static DEFINE_MUTEX(cscfg_mutex);

+/* only one of these */ +static struct cscfg_manager *cscfg_mgr;

+/* load features and configuations into the lists */

+/* check feature list for a named feature - call with mutex locked. */ +static bool cscfg_match_list_feat(const char *name) +{

• struct cscfg_feature_desc *curr_item;
  

• list_for_each_entry(curr_item, &cscfg_mgr->data.feat_desc_list, item) {
  

•         if (strcmp(curr_item->name, name) == 0)
  

•                 return true;
  

• }
  

• return false;
  

+}

+/* check all feat needed for cfg are in the list - call with mutex locked. */ +static int cscfg_check_feat_for_cfg(struct cscfg_config_desc *cfg_desc) +{

• int i;
  

• for (i = 0; i < cfg_desc->nr_refs; i++)
  

•         if (!cscfg_match_list_feat(cfg_desc->refs[i].name))
  

•                 return -EINVAL;
  

• return 0;
  

+}

+/*

• • load feature - add to feature list.
• */

+static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc) +{

• list_add(&feat_desc->item, &cscfg_mgr->data.feat_desc_list);
  

• return 0;
  

+}

+/*

• • load config into the system - validate used features exist then add to
• • config list.
• */

+static int cscfg_load_config(struct cscfg_config_desc *cfg_desc) +{

• int err;
  

• /* validate features are present */
  

• err = cscfg_check_feat_for_cfg(cfg_desc);
  

• if (err)
  

•         return err;
  

• list_add(&cfg_desc->item, &cscfg_mgr->data.config_desc_list);
  

• return 0;
  

+}

+/*

• • External API function to load feature and config sets.
• • Take a 0 terminated array of feature descriptors and/or configuration
• • descriptors and load into the system.
• • Features are loaded first to ensure configuration dependencies can be met.
• */

+int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,

•                    struct cscfg_feature_desc **feat_descs)
  

+{

• int err, i = 0;
  

• mutex_lock(&cscfg_mutex);
  

• /* load features first */
  

• if (feat_descs) {
  

•         while (feat_descs[i]) {
  

•                 err = cscfg_load_feat(feat_descs[i]);
  

•                 if (err) {
  

•                         pr_err("coresight-syscfg: Failed to load feature %s\n",
  

•                                feat_descs[i]->name);
  

•                         goto do_unlock;
  

•                 }
  

•                 i++;
  

•         }
  

• }
  

• /* next any configurations to check feature dependencies */
  

• i = 0;
  

• if (cfg_descs) {
  

•         while (cfg_descs[i]) {
  

•                 err = cscfg_load_config(cfg_descs[i]);
  

•                 if (err) {
  

•                         pr_err("coresight-syscfg: Failed to load configuration %s\n",
  

•                                cfg_descs[i]->name);
  

•                         goto do_unlock;
  

•                 }
  

•                 i++;
  

•         }
  

• }
  

+do_unlock:

• mutex_unlock(&cscfg_mutex);
  

• return err;
  

+} +EXPORT_SYMBOL_GPL(cscfg_load_config_sets);

It looks like we keep the features and configs in the global list, even when there was a failure halfway. This could be problematic, as the caller could release/free the nodes we added and walking the list is going to explode. So, we either:

1. Do this in 2 pass. Check if the features and the configs can be loaded in first pass. And load them in the second pass.

OR

2. Add cleanup code to remove the items that were added.

Since we do this with the mutex lock, we should be fine.

In this initial set we are trying to keep to the minimum baseline to provide the overall structure, with the autofdo configuration as a built in. Now we know that this configuration is by definition correct, so for this baseline set at least, the code is guaranteed to work. We are not allowing additional user configs at this point.

There is a follow-up patch set that includes code to allow for dynamic loading and unloading of configurations and features, and this includes the correct error clean up, dependency locking to prevent in-use configs from being unloaded, along with an example of how to define a loadable module that loads a new set of configs / features. But this adds a whole lot more code that is not needed in this baseline set.

...

+/* Initialise system configuration management device. */

+struct device *to_device_cscfg(void)

minor nit: to_device_cscfg() implies you are converting something to a device. But since this is a global device it could be better named as :

struct device *cscfg_device(void);

Agreed.

...

+{

• return cscfg_mgr ? &cscfg_mgr->dev : NULL;
  

+}

+/* Must have a release function or the kernel will complain on module unload */ +void cscfg_dev_release(struct device *dev) +{

• kfree(cscfg_mgr);
  

• cscfg_mgr = NULL;
  

+}

+/* a device is needed to "own" some kernel elements such as sysfs entries. */ +int cscfg_create_device(void) +{

• struct device *dev;
  

• int err = -ENOMEM;
  

• mutex_lock(&cscfg_mutex);
  

• if (cscfg_mgr) {
  

•         err = -EINVAL;
  

•         goto create_dev_exit_unlock;
  

• }
  

• cscfg_mgr = kzalloc(sizeof(struct cscfg_manager), GFP_KERNEL);
  

• if (!cscfg_mgr)
  

•         goto create_dev_exit_unlock;
  

• /* setup the device */
  

• dev = to_device_cscfg();
  

• dev->release = cscfg_dev_release;
  

• dev->init_name = "system_cfg";
  

nit: Does it make sense to have "cs" somewhere in the name ?

It does. It's not something that the user would ever see / use, but no doubt linux makes hte name visible in a list somewhere.

...

• err = device_register(dev);
  

• if (err)
  

•         cscfg_dev_release(dev);
  

+create_dev_exit_unlock:

• mutex_unlock(&cscfg_mutex);
  

• return err;
  

+}

+void cscfg_clear_device(void) +{

• mutex_lock(&cscfg_mutex);
  

• device_unregister(to_device_cscfg());
  

• mutex_unlock(&cscfg_mutex);
  

+}

+/* Initialise system config management API device */ +int __init cscfg_init(void) +{

• int err = 0;
  

• err = cscfg_create_device();
  

• if (err)
  

•         return err;
  

• INIT_LIST_HEAD(&cscfg_mgr->data.csdev_desc_list);
  

• INIT_LIST_HEAD(&cscfg_mgr->data.feat_desc_list);
  

• INIT_LIST_HEAD(&cscfg_mgr->data.config_desc_list);
  

• cscfg_mgr->data.nr_csdev = 0;
  

• dev_info(to_device_cscfg(), "CoreSight Configuration manager initialised");
  

• return 0;
  

+}

+void __exit cscfg_exit(void) +{

• cscfg_clear_device();
  

+} diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h new file mode 100644 index 000000000000..907ba8d3efea --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/*

• • Coresight system configuration driver.
• */

+#ifndef CORESIGHT_SYSCFG_H +#define CORESIGHT_SYSCFG_H

+#include <linux/coresight.h> +#include <linux/device.h>

+#include "coresight-config.h"

+/**

• • System configuration manager API data.
• • @csdev_list: List of coresight devices registered with the configuration manager.

Doesn't match the variable name below.

OK - will fix.

...

• • @feat_desc_list: List of feature descriptors to load into registered devices.
• • @config_desc_list: List of system configuration descriptors to load into registered devices.
• • @nr_csdev: Number of registered devices with the cscfg system
• */

+struct cscfg_api_data {

• struct list_head csdev_desc_list;
  

• struct list_head feat_desc_list;
  

• struct list_head config_desc_list;
  

• int nr_csdev;
  

+};

+/* internal core operations for cscfg */ +int __init cscfg_init(void); +void __exit cscfg_exit(void);

+/* syscfg manager external API */ +int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,

•                    struct cscfg_feature_desc **feat_descs);
  

---> Cut here <---

...

+/**

• • System configuration manager device.
• • Need a device to 'own' some coresight system wide sysfs entries in
• • perf events, configfs etc.
• • @dev: The device.
• • @data: The API data.
• */

+struct cscfg_manager {

• struct device dev;
  

• struct cscfg_api_data data;
  

+};

+/* get reference to dev in cscfg_manager */ +struct device *to_device_cscfg(void);

--> Cut End <---

Do the above need to be exposed outside the core coresight-syscfg.c ?

Yes - they are used in the following patches in this set. They are made visible here to avoid changing later in the patchset, which tends to attract comments.

Cheers Suzuki

Thanks for the review

Mike

On 1/28/21 5:09 PM, Mike Leach wrote:

Creates an system management API to allow complex configurations and features to be programmed into a CoreSight infrastructure.

A feature is defined as a programming set for a device or class of devices.

A configuration is a set of features across the system that are enabled for a trace session.

The API will manage system wide configuration, and allow complex programmed features to be added to individual device instances, and provide for system wide configuration selection on trace capture operations.

This patch creates the initial data object and the initial API for loading configurations and features.

Signed-off-by: Mike Leach mike.leach@linaro.org

drivers/hwtracing/coresight/Makefile | 2 +- .../hwtracing/coresight/coresight-config.h | 167 +++++++++++++++ drivers/hwtracing/coresight/coresight-core.c | 12 +- .../hwtracing/coresight/coresight-etm-perf.c | 2 +- .../hwtracing/coresight/coresight-etm-perf.h | 2 +- .../hwtracing/coresight/coresight-syscfg.c | 197 ++++++++++++++++++ .../hwtracing/coresight/coresight-syscfg.h | 54 +++++ 7 files changed, 432 insertions(+), 4 deletions(-) create mode 100644 drivers/hwtracing/coresight/coresight-config.h create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.c create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.h

diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index f20e357758d1..4ce854c434b1 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -4,7 +4,7 @@ # obj-$(CONFIG_CORESIGHT) += coresight.o coresight-y := coresight-core.o coresight-etm-perf.o coresight-platform.o \

• coresight-sysfs.o
  

• coresight-sysfs.o coresight-syscfg.o
  

  obj-$(CONFIG_CORESIGHT_LINK_AND_SINK_TMC) += coresight-tmc.o coresight-tmc-y := coresight-tmc-core.o coresight-tmc-etf.o \ coresight-tmc-etr.o

diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h new file mode 100644 index 000000000000..3fedf8ab3cee --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -0,0 +1,167 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*

• • Copyright (c) 2020 Linaro Limited, All rights reserved.
• • Author: Mike Leach mike.leach@linaro.org
• */

+#ifndef _CORESIGHT_CORESIGHT_CONFIG_H +#define _CORESIGHT_CORESIGHT_CONFIG_H

+#include <linux/coresight.h> +#include <linux/types.h>

+/* CoreSight Configuration Management - component and system wide configuration */

+/*

• • Register type flags for register value descriptor:
• • describe how the value is interpreted, and handled.
• */

+#define CS_CFG_REG_TYPE_STD 0x80 /* reg is standard reg */ +#define CS_CFG_REG_TYPE_RESOURCE 0x40 /* reg is a resource */ +#define CS_CFG_REG_TYPE_VAL_PARAM 0x08 /* reg value uses param */ +#define CS_CFG_REG_TYPE_VAL_MASK 0x04 /* reg value bit masked */ +#define CS_CFG_REG_TYPE_VAL_64BIT 0x02 /* reg value 64 bit */ +#define CS_CFG_REG_TYPE_VAL_SAVE 0x01 /* reg value save on disable */

+/*

• • flags defining what device class a feature will match to when processing a
• • system configuration - used by config data and devices.
• */

+#define CS_CFG_MATCH_CLASS_SRC_ALL 0x0001 /* match any source */ +#define CS_CFG_MATCH_CLASS_SRC_ETM4 0x0002 /* match any ETMv4 device */

+/* flags defining device instance matching - used in config match desc data. */ +#define CS_CFG_MATCH_INST_ANY 0x80000000 /* any instance of a class */

+/*

• • Limit number of presets in a configuration
• • This is related to the number of bits (4) we use to select the preset on
• • the perf command line. Preset 0 is always none selected.
• • See PMU_FORMAT_ATTR(preset, "config:0-3") in coresight-etm-perf.c
• */

+#define CS_CFG_CONFIG_PRESET_MAX 15

+/**

• • Parameter descriptor for a device feature.
• • @name: Name of parameter.
• • @value: Initial or default value.
• */

+struct cscfg_parameter_desc {

• const char *name;
• u64 value;

+};

+/**

• • Representation of register value.
• • Supports full 64 bit register value, or 32 bit value with optional mask
• • value.
• • @type: define register usage and interpretation.
• • @offset: the address offset for register in the hardware device (per device specification).
• • @hw_info: optional hardware device type specific information. (ETM / CTI specific etc)
• • @val64: 64 bit value.
• • @val32: 32 bit value.
• • @mask32: 32 bit mask when using 32 bit value to access device register.
• */

+struct cscfg_regval_desc {

• struct {

• u32 type:8;
  

• u32 offset:12;
  

• u32 hw_info:12;
  

• };
• union {

• u64 val64;
  

• struct {
  

• 	u32 val32;
  

• 	u32 mask32;
  

• };
  

• };

+};

+/**

• • Device feature descriptor - combination of registers and parameters to
• • program a device to implement a specific complex function.
• • @name: feature name.
• • @brief: brief description of the feature.
• • @item: List entry.
• • @match_flags: matching information if loading into a device
• • @nr_params: number of parameters used.
• • @params: array of parameters used.
• • @nr_regs: number of registers used.
• • @reg: array of registers used.
• */

+struct cscfg_feature_desc {

• const char *name;
• const char *brief;
• struct list_head item;
• u32 match_flags;
• int nr_params;
• struct cscfg_parameter_desc *params;
• int nr_regs;
• struct cscfg_regval_desc *regs;

+};

+/**

• • Match descriptor - Device / feature matching when loading into devices
• • Used by loading configurations to define which class or specific devices
• • they want to match used features to, and registered devices to specify which
• • matching class and information they support.
• • The load process uses these matching pairs to load feature instances into
• • matching devices.
• • @match_flags: used to match to a particular class of device.
• */

+struct cscfg_match_desc {

• u32 match_flags;

+};

+/**

• • Descriptor for features referenced by a configuration.
• • @name: name of feature to use. Match against the @name in struct

• • cscfg_feature_desc.
    

• • @match: match info for the feature when used in this configuration -

• • may be all devices of a class or a specific device in that class.
    

• */

+struct cscfg_config_feat_ref {

• const char *name;
• struct cscfg_match_desc match;

+};

+/**

• • Configuration descriptor - describes selectable system configuration.
• • A configuration describes device features in use, and may provide preset
• • values for the parameters in those features.
• • A single set of presets is the sum of the parameters declared by
• • all the features in use - this value is @nr_total_params.
• • @name: name of the configuration - used for selection.
• • @brief: description of the purpose of the configuration.
• • @item: list entry.
• • @nr_refs: Number of features used in this configuration.
• • @refs: references to features used in this configuration..
• • @nr_presets: Number of sets of presets supplied by this configuration.
• • @nr_total_params: Sum of all parameters declared by used features
• • @presets: Array of preset values.
• */

+struct cscfg_config_desc {

• const char *name;
• const char *brief;
• struct list_head item;
• int nr_refs;
• struct cscfg_config_feat_ref *refs;

s/refs/config_feat_refs/ ?

In general please name the fields to make it easier to infer the type, given the number of structures we deal with, it becomes very difficult to track while reading the code.

Cheers Suzuki

[...]

+/**

• • List entry for Coresight devices that are registered as supporting complex
• • config operations.
• • @csdev: The registered device.
• • @match_info: The matching type information.
• • @ops: Operations supported by the registered device.
• • @item: list entry.
• */

+struct cscfg_csdev_register {

• struct coresight_device *csdev;
• struct cscfg_match_desc match_info;
• struct cscfg_csdev_feat_ops ops;
• struct list_head item;

+};

I would call this structure cscfg_registered_csdev and move it to coresight-config.h. That way it is consistent with cscfg_config_csdev and cscfg_feature_csdev and located all in the same file.

I may have to come back to this patch but for now it holds together.

More comments to come on Monday.

Thanks, Mathieu

/* internal core operations for cscfg */ int __init cscfg_init(void); void __exit cscfg_exit(void); @@ -33,6 +49,10 @@ void __exit cscfg_exit(void); /* syscfg manager external API */ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, struct cscfg_feature_desc **feat_descs); +int cscfg_register_csdev(struct coresight_device *csdev,

• 	 struct cscfg_match_desc *info,
  

• 	 struct cscfg_csdev_feat_ops *ops);
  

+void cscfg_unregister_csdev(struct coresight_device *csdev); /**

• System configuration manager device.

diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 976ec2697610..d0126ed326a6 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -219,6 +219,8 @@ struct coresight_sysfs_link {

• @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.

• • @feature_csdev_list: List of complex feature programming added to the device.
• • @config_csdev_list: List of system configurations added to the device.
  */

struct coresight_device { struct coresight_platform_data *pdata; @@ -240,6 +242,9 @@ struct coresight_device { int nr_links; bool has_conns_grp; bool ect_enabled; /* true only if associated ect device is enabled */

• /* system configuration and feature lists */
• struct list_head feature_csdev_list;
• struct list_head config_csdev_list;

}; /* -- 2.17.1

Hi Mathieu,

On Mon, 22 Feb 2021 at 17:38, Mathieu Poirier mathieu.poirier@linaro.org wrote:

Hi Mike,

On Thu, Jan 28, 2021 at 05:09:28PM +0000, Mike Leach wrote:

...

API for individual devices to register with the syscfg management system is added.

Devices register with matching information, and any features or configurations that match will be loaded into the device.

The feature and configuration loading is extended so that on load these are loaded into any currently registered devices. This allows configuration loading after devices have been registered.

Signed-off-by: Mike Leach mike.leach@linaro.org

.../hwtracing/coresight/coresight-config.h | 98 +++++ .../hwtracing/coresight/coresight-syscfg.c | 348 ++++++++++++++++++ .../hwtracing/coresight/coresight-syscfg.h | 20 + include/linux/coresight.h | 5 + 4 files changed, 471 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index 3fedf8ab3cee..75ecdecf7013 100644 --- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -164,4 +164,102 @@ struct cscfg_config_desc { const u64 *presets; /* nr_presets * nr_total_params */ };

+/**

• • config register instance - part of a loaded feature.

• •                        maps register values to csdev driver structures
    

• • @value: value to use when setting feature on device / store for

• •       readback of volatile values.
    

• • @drv_store: pointer to internal driver element used to set the value

• •       in hardware.
    

• */

+struct cscfg_reg_csdev {

Please rename this cscfg_regval_csdev to highlight the 1:1 mapping with cscfg_regval_desc. Or rename cscfg_regval_desc to cscfg_reg_desc. I have no opinion on which one it should be, as long as they are consistent. Doing so really helps getting over the naming convention so that we can focus on the core of the feature.

Will do.

...

• struct cscfg_regval_desc value;
  

• void *drv_store;
  

+};

+/**

• • config parameter instance - part of a loaded feature.
• • @feat: parent feature
• • @reg: register value updated by this parameter.
• • @current_value: current value of parameter - may be set by user via

• •               sysfs, or modified during device operation.
    

• • @val64: true if 64 bit value
• */

+struct cscfg_parameter_csdev {

• struct cscfg_feature_csdev *feat;
  

• struct cscfg_reg_csdev *reg;
  

• u64 current_value;
  

• bool val64;
  

+};

+/**

• • Feature instance loaded into a CoreSight device.
• • When a feature is loaded into a specific device, then this structure holds
• • the connections between the register / parameter values used and the
• • internal data structures that are written when the feature is enabled.
• • Since applying a feature modifies internal data structures in the device,
• • then we have a reference to the device spinlock to protect access to these
• • structures (@csdev_spinlock).
• • @desc: pointer to the static descriptor for this feature.
• • @csdev: parent CoreSight device instance.
• • @node: list entry into feature list for this device.
• • @csdev_spinlock: device spinlock from csdev instance..
• • @nr_params: number of parameters.
• • @params: current parameter values on this device
• • @nr_regs: number of registers to be programmed.
• • @regs: Programming details for the registers
• */

+struct cscfg_feature_csdev {

• const struct cscfg_feature_desc *desc;
  

• struct coresight_device *csdev;
  

• struct list_head node;
  

• spinlock_t *csdev_spinlock;
  

• int nr_params;
  

• struct cscfg_parameter_csdev *params;
  

• int nr_regs;
  

• struct cscfg_reg_csdev *regs;
  

+};

+/**

• • Configuration instance when loaded into a CoreSight device.
• • The instance contains references to loaded features on this device that are
• • used by the configuration.
• • @desc: reference to the descriptor for this configuration
• • @csdev: parent coresight device for this configuration instance.
• • @node: list entry within the coresight device
• • @nr_feat: Number of features on this device that are used in the

• •        configuration.
    

• • @feats: reference to the device features to enable.
• • @enabled: true if configuration is enabled on this device.
• */

+struct cscfg_config_csdev {

• const struct cscfg_config_desc *desc;
  

• struct coresight_device *csdev;
  

• struct list_head node;
  

• int nr_feat;
  

• struct cscfg_feature_csdev **feats;
  

• bool enabled;
  

+};

+/**

• • Coresight device operations.
• • Registered coresight devices provide these operations to manage feature
• • instances compatible with the device hardware and drivers
• • @load_feat: Pass a feature descriptor into the device and create the

• •       loaded feature instance (struct cscfg_feature_csdev).
    

• */

+struct cscfg_csdev_feat_ops {

• int (*load_feat)(struct coresight_device *csdev,
  

•                  struct cscfg_feature_csdev *feat);
  

+};

#endif /* _CORESIGHT_CORESIGHT_CONFIG_H */ diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index f7e396a5f9cb..c04cea0c1db2 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -25,6 +25,212 @@ static struct cscfg_manager *cscfg_mgr;

/* load features and configuations into the lists */

+/* protect the cfg lists in the csdev instances */ +static DEFINE_MUTEX(cscfg_csdev_mutex);

+/* get name feature instance from a coresight device list of features */ +static struct cscfg_feature_csdev * +cscfg_get_feat_csdev(struct coresight_device *csdev, const char *name) +{

• struct cscfg_feature_csdev *feat = NULL;
  

• list_for_each_entry(feat, &csdev->feature_csdev_list, node) {
  

•         if (strcmp(feat->desc->name, name) == 0)
  

•                 return feat;
  

• }
  

• return NULL;
  

+}

+/* allocate the device config instance - with max number of used features */ +static struct cscfg_config_csdev * +cscfg_alloc_csdev_cfg(struct coresight_device *csdev, int nr_feats) +{

• struct cscfg_config_csdev *dev_cfg = NULL;
  

• struct device *dev = csdev->dev.parent;
  

• /* this is being allocated using the devm for the coresight device */
  

• dev_cfg = devm_kzalloc(dev, sizeof(struct cscfg_config_csdev), GFP_KERNEL);
  

• if (!dev_cfg)
  

•         return NULL;
  

• dev_cfg->csdev = csdev;
  

• dev_cfg->feats = devm_kcalloc(dev, nr_feats,
  

•                               sizeof(struct cscfg_feature_csdev *),
  

•                               GFP_KERNEL);
  

• if (!dev_cfg->feats)
  

•         dev_cfg = NULL;
  

• return dev_cfg;
  

+}

+/* check match info between used feature from the config and a regisered device */ +static bool cscfg_match_feat_info(struct cscfg_match_desc *used_cmp,

•                           struct cscfg_match_desc *reg_dev)
  

+{

• /* if flags don't match then fail early */
  

• if (!(used_cmp->match_flags & reg_dev->match_flags))
  

•         return false;
  

• return true;
  

+}

+/* Load a config into a device if there are feature matches between config and device */ +static int cscfg_add_csdev_cfg(struct coresight_device *csdev,

•                        struct cscfg_match_desc *match_info,
  

•                        struct cscfg_config_desc *cfg_desc)
  

                            struct cscfg_config_desc *config_desc)

OK

...

+{

• struct cscfg_config_csdev *dev_cfg = NULL;
  

    struct cscfg_config_csdev *config_csdev = NULL;

...

• struct cscfg_config_feat_ref *feat_ref;
  

• struct cscfg_feature_csdev *feat;
  

    struct cscfg_feature_csdev *feat_csdev;

OK

Please appy this kind of naming convention throughout the patchset.

Agreed - I'll update the nameing convention in the next set.

Thanks

Mike

...

• int checked;
  

• /* look at each required feature and see if it matches any feature on the device */
  

• for (checked = 0; checked < cfg_desc->nr_refs; checked++) {
  

•         feat_ref = &cfg_desc->refs[checked];
  

•         if (cscfg_match_feat_info(&feat_ref->match, match_info)) {
  

•                 /* device matched - get the feature */
  

•                 feat = cscfg_get_feat_csdev(csdev, feat_ref->name);
  

•                 if (!feat)
  

•                         return -EINVAL;
  

•                 if (!dev_cfg) {
  

•                         dev_cfg = cscfg_alloc_csdev_cfg(csdev, cfg_desc->nr_refs);
  

•                         if (!dev_cfg)
  

•                                 return -ENOMEM;
  

•                         dev_cfg->desc = cfg_desc;
  

•                 }
  

•                 dev_cfg->feats[dev_cfg->nr_feat++] = feat;
  

•         }
  

• }
  

• /* if matched features, add config to device.*/
  

• if (dev_cfg) {
  

•         mutex_lock(&cscfg_csdev_mutex);
  

•         list_add(&dev_cfg->node, &csdev->config_csdev_list);
  

•         mutex_unlock(&cscfg_csdev_mutex);
  

• }
  

• return 0;
  

+}

+/*

• • Add the config to the set of registered devices - call with mutex locked.
• • Iterates through devices - any device that matches one or more of the
• • configuration features will load it, the others will ignore it.
• */

+static int cscfg_add_cfg_to_csdevs(struct cscfg_config_desc *cfg_desc) +{

• struct cscfg_csdev_register *curr_item;
  

• int err;
  

• list_for_each_entry(curr_item, &cscfg_mgr->data.csdev_desc_list, item) {
  

•         err = cscfg_add_csdev_cfg(curr_item->csdev, &curr_item->match_info, cfg_desc);
  

•         if (err)
  

•                 return err;
  

• }
  

• return 0;
  

+}

+/*

• • Allocate a feature object for load into a csdev.
• • memory allocated using the csdev->dev object using devm managed allocator.
• */

+static struct cscfg_feature_csdev * +cscfg_alloc_csdev_feat(struct coresight_device *csdev, struct cscfg_feature_desc *feat_desc) +{

• struct cscfg_feature_csdev *feat = NULL;
  

struct cscfg_feature_csdev *feat_csdev = NULL;

...

• struct device *dev = csdev->dev.parent;
  

• int i;
  

• feat = devm_kzalloc(dev, sizeof(struct cscfg_feature_csdev), GFP_KERNEL);
  

• if (!feat)
  

•         return NULL;
  

• /* parameters are optional - could be 0 */
  

• feat->nr_params = feat_desc->nr_params;
  

• /*
  

•  * if we need parameters, zero alloc the space here, the load routine in
  

•  * the csdev device driver will fill out some information according to
  

•  * feature descriptor.
  

•  */
  

• if (feat->nr_params) {
  

•         feat->params = devm_kcalloc(dev, feat->nr_params,
  

•                                     sizeof(struct cscfg_parameter_csdev),
  

•                                     GFP_KERNEL);
  

•         if (!feat->params)
  

•                 return NULL;
  

•         /*
  

•          * fill in the feature reference in the param - other fields
  

•          * handled by loader in csdev.
  

•          */
  

•         for (i = 0; i < feat->nr_params; i++)
  

•                 feat->params[i].feat = feat;
  

• }
  

• /*
  

•  * Always have registers to program - again the load routine in csdev device
  

•  * will fill out according to feature descriptor and device requirements.
  

•  */
  

• feat->nr_regs = feat_desc->nr_regs;
  

• feat->regs = devm_kcalloc(dev, feat->nr_regs,
  

•                           sizeof(struct cscfg_reg_csdev), GFP_KERNEL);
  

• if (!feat->regs)
  

•         return NULL;
  

• /* load the feature default values */
  

• feat->desc = feat_desc;
  

• feat->csdev = csdev;
  

• return feat;
  

+}

+/* load one feature into one coresight device */ +static int cscfg_load_feat_csdev(struct coresight_device *csdev,

•                          struct cscfg_feature_desc *feat_desc,
  

•                          struct cscfg_csdev_feat_ops *ops)
  

+{

• struct cscfg_feature_csdev *feat_csdev;
  

• int err;
  

• if (!ops->load_feat)
  

•         return -EINVAL;
  

• feat_csdev = cscfg_alloc_csdev_feat(csdev, feat_desc);
  

• if (!feat_csdev)
  

•         return -ENOMEM;
  

• /* load the feature into the device - may modify default ops*/
  

• err = ops->load_feat(csdev, feat_csdev);
  

• if (err)
  

•         return err;
  

• /* add to internal csdev feature list */
  

• mutex_lock(&cscfg_csdev_mutex);
  

• list_add(&feat_csdev->node, &csdev->feature_csdev_list);
  

• mutex_unlock(&cscfg_csdev_mutex);
  

• return 0;
  

+}

+/*

• • Add feature to any matching devices - call with mutex locked.
• • Iterates through devices - any device that matches the feature will be
• • called to load it.
• */

+static int cscfg_add_feat_to_csdevs(struct cscfg_feature_desc *feat_desc) +{

• struct cscfg_csdev_register *curr_item;
  

• int err;
  

• list_for_each_entry(curr_item, &cscfg_mgr->data.csdev_desc_list, item) {
  

•         if (curr_item->match_info.match_flags & feat_desc->match_flags) {
  

•                 err = cscfg_load_feat_csdev(curr_item->csdev, feat_desc, &curr_item->ops);
  

•                 if (err)
  

•                         return err;
  

•         }
  

• }
  

• return 0;
  

+}

/* check feature list for a named feature - call with mutex locked. */ static bool cscfg_match_list_feat(const char *name) { @@ -53,6 +259,13 @@ static int cscfg_check_feat_for_cfg(struct cscfg_config_desc *cfg_desc) */ static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc) {

• int err;
  

• /* add feature to any matching registered devices */
  

• err = cscfg_add_feat_to_csdevs(feat_desc);
  

• if (err)
  

•         return err;
  

• list_add(&feat_desc->item, &cscfg_mgr->data.feat_desc_list);
  
  return 0;
  

@@ -71,6 +284,11 @@ static int cscfg_load_config(struct cscfg_config_desc *cfg_desc) if (err) return err;

• /* add config to any matching registered device */
  

• err = cscfg_add_cfg_to_csdevs(cfg_desc);
  

• if (err)
  

•         return err;
  

• list_add(&cfg_desc->item, &cscfg_mgr->data.config_desc_list);
  
  return 0;
  

@@ -122,6 +340,136 @@ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, } EXPORT_SYMBOL_GPL(cscfg_load_config_sets);

+/* Handle coresight device registration and add configs and features to devices */

+/* iterate through config lists and load matching configs to device */ +static int cscfg_add_cfgs_csdev(struct coresight_device *csdev,

•                         struct cscfg_match_desc *info)
  

+{

• struct cscfg_config_desc *curr_item;
  

• int err = 0;
  

• list_for_each_entry(curr_item, &cscfg_mgr->data.config_desc_list, item) {
  

•         err = cscfg_add_csdev_cfg(csdev, info, curr_item);
  

•         if (err)
  

•                 break;
  

• }
  

• return err;
  

+}

+/* iterate through feature lists and load matching features to device */ +static int cscfg_add_feats_csdev(struct coresight_device *csdev,

•                          struct cscfg_match_desc *info,
  

•                          struct cscfg_csdev_feat_ops *ops)
  

+{

• struct cscfg_feature_desc *curr_item;
  

• int err = 0;
  

• if (!ops->load_feat)
  

•         return -EINVAL;
  

• list_for_each_entry(curr_item, &cscfg_mgr->data.feat_desc_list, item) {
  

•         if (curr_item->match_flags & info->match_flags) {
  

•                 err = cscfg_load_feat_csdev(csdev, curr_item, ops);
  

•                 if (err)
  

•                         break;
  

•         }
  

• }
  

• return err;
  

+}

+/* Add coresight device to list and copy its matching info */ +static int cscfg_list_add_csdev(struct coresight_device *csdev,

•                         struct cscfg_match_desc *info,
  

•                         struct cscfg_csdev_feat_ops *ops)
  

+{

• struct cscfg_csdev_register *list_entry;
  

• /* allocate the list entry structure */
  

• list_entry = kzalloc(sizeof(struct cscfg_csdev_register), GFP_KERNEL);
  

• if (!list_entry)
  

•         return -ENOMEM;
  

• list_entry->csdev = csdev;
  

• list_entry->match_info.match_flags = info->match_flags;
  

• list_entry->ops.load_feat = ops->load_feat;
  

• list_add(&list_entry->item, &cscfg_mgr->data.csdev_desc_list);
  

• INIT_LIST_HEAD(&csdev->feature_csdev_list);
  

• INIT_LIST_HEAD(&csdev->config_csdev_list);
  

• cscfg_mgr->data.nr_csdev++;
  

• return 0;
  

+}

+/* remove a coresight device from the list and free data */ +static void cscfg_list_remove_csdev(struct coresight_device *csdev) +{

• struct cscfg_csdev_register *curr_item, *tmp;
  

• list_for_each_entry_safe(curr_item, tmp, &cscfg_mgr->data.csdev_desc_list, item) {
  

•         if (curr_item->csdev == csdev) {
  

•                 list_del(&curr_item->item);
  

•                 kfree(curr_item);
  

•                 cscfg_mgr->data.nr_csdev--;
  

•                 break;
  

•         }
  

• }
  

+}

+/* register a coresight device with the syscfg api */ +int cscfg_register_csdev(struct coresight_device *csdev,

•                  struct cscfg_match_desc *info,
  

•                  struct cscfg_csdev_feat_ops *ops)
  

+{

• int ret = 0;
  

• mutex_lock(&cscfg_mutex);
  

• /* add device to list of registered devices  */
  

• ret = cscfg_list_add_csdev(csdev, info, ops);
  

• if (ret)
  

•         goto reg_csdev_unlock;
  

• /* now load any registered features and configs matching the device. */
  

• ret = cscfg_add_feats_csdev(csdev, info, ops);
  

• if (ret) {
  

•         cscfg_list_remove_csdev(csdev);
  

•         goto reg_csdev_unlock;
  

• }
  

• ret = cscfg_add_cfgs_csdev(csdev, info);
  

• if (ret) {
  

•         cscfg_list_remove_csdev(csdev);
  

•         goto reg_csdev_unlock;
  

• }
  

• pr_info("CSCFG registered %s", dev_name(&csdev->dev));
  

+reg_csdev_unlock:

• mutex_unlock(&cscfg_mutex);
  

• return ret;
  

+} +EXPORT_SYMBOL_GPL(cscfg_register_csdev);

+/* remove coresight device and update counts - syscfg device at 0 */ +void cscfg_unregister_csdev(struct coresight_device *csdev) +{

• struct cscfg_csdev_register *curr_item, *tmp;
  

• mutex_lock(&cscfg_mutex);
  

• list_for_each_entry_safe(curr_item, tmp, &cscfg_mgr->data.csdev_desc_list, item) {
  

•         if (curr_item->csdev == csdev) {
  

•                 list_del(&curr_item->item);
  

•                 kfree(curr_item);
  

•                 cscfg_mgr->data.nr_csdev--;
  

•                 break;
  

•         }
  

• }
  

• mutex_unlock(&cscfg_mutex);
  

+} +EXPORT_SYMBOL_GPL(cscfg_unregister_csdev);

/* Initialise system configuration management device. */

struct device *to_device_cscfg(void) diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index 907ba8d3efea..ebf5e1491d86 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -26,6 +26,22 @@ struct cscfg_api_data { int nr_csdev; };

+/**

• • List entry for Coresight devices that are registered as supporting complex
• • config operations.
• • @csdev: The registered device.
• • @match_info: The matching type information.
• • @ops: Operations supported by the registered device.
• • @item: list entry.
• */

+struct cscfg_csdev_register {

• struct coresight_device *csdev;
  

• struct cscfg_match_desc match_info;
  

• struct cscfg_csdev_feat_ops ops;
  

• struct list_head item;
  

+};

/* internal core operations for cscfg */ int __init cscfg_init(void); void __exit cscfg_exit(void); @@ -33,6 +49,10 @@ void __exit cscfg_exit(void); /* syscfg manager external API */ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, struct cscfg_feature_desc **feat_descs); +int cscfg_register_csdev(struct coresight_device *csdev,

•                  struct cscfg_match_desc *info,
  

•                  struct cscfg_csdev_feat_ops *ops);
  

+void cscfg_unregister_csdev(struct coresight_device *csdev);

/**

• System configuration manager device.

diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 976ec2697610..d0126ed326a6 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -219,6 +219,8 @@ struct coresight_sysfs_link {

• @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.

• • @feature_csdev_list: List of complex feature programming added to the device.
• • @config_csdev_list: List of system configurations added to the device.
  */

struct coresight_device { struct coresight_platform_data *pdata; @@ -240,6 +242,9 @@ struct coresight_device { int nr_links; bool has_conns_grp; bool ect_enabled; /* true only if associated ect device is enabled */

• /* system configuration and feature lists */
  

• struct list_head feature_csdev_list;
  

• struct list_head config_csdev_list;
  

};

/*

2.17.1