[RFC PATCH v3 1/9] coresight: syscfg: Initial coresight system configuration
Mathieu Poirier
mathieu.poirier at linaro.org
Mon Nov 16 13:32:03 EST 2020
On Fri, Oct 30, 2020 at 05:56:47PM +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 at linaro.org>
> ---
> drivers/hwtracing/coresight/Makefile | 2 +-
> .../hwtracing/coresight/coresight-config.h | 170 ++++++++++++
> 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 | 247 ++++++++++++++++++
> .../hwtracing/coresight/coresight-syscfg.h | 57 ++++
> 7 files changed, 488 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..0d9ae1dc4517
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-config.h
> @@ -0,0 +1,170 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2020 Linaro Limited, All rights reserved.
> + * Author: Mike Leach <mike.leach at linaro.org>
> + */
> +
> +#ifndef _CORESIGHT_CORESIGHT_CONFIG_H
> +#define _CORESIGHT_CORESIGHT_CONFIG_H
> +
> +#include <linux/coresight.h>
> +#include <linux/types.h>
> +
> +/* CoreSight Configuration - complex component and system config handling */
> +
> +/* generic register flags */
> +#define CS_CFG_REG_STD 0x80000000 /* reg is standard reg */
> +#define CS_CFG_REG_RESOURCE 0x40000000 /* reg is a resource */
> +#define CS_CFG_REG_VAL_PARAM 0x08000000 /* reg value uses param */
> +#define CS_CFG_REG_VAL_MASK 0x04000000 /* reg value bit masked */
> +#define CS_CFG_REG_VAL_64BIT 0x02000000 /* reg value 64 bit */
> +#define CS_CFG_REG_VAL_SAVE 0x01000000 /* reg value save on disable */
> +#define CS_CFG_REG_ID_MASK 0x00000FFF /* reg offset / id in device */
> +#define CS_CFG_REG_DEV_MASK 0x00FFF000 /* device specific flags */
> +
> +/*
> + * 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 */
> +#define CS_CFG_MATCH_CLASS_CTI_ALL 0x0004 /* match any CTI device */
> +#define CS_CFG_MATCH_CLASS_CTI_CPU 0x0008
> +#define CS_CFG_MATCH_CLASS_CTI_SYS 0x0010
> +
> +/* flags defining device instance matching - used in config data. */
> +#define CS_CFG_MATCH_INST_ANY 0x80000000 /* any instance of a class */
> +#define CS_CFG_MATCH_INST_AMBA_DEVICE 0x40000000 /* specific amba device */
> +
> +/*
> + * 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.
> + *
> + * @flags: define value usage as 32bit, 32bit+mask or 64bit.
> + * @val64: 64 bit value.
> + * @val32: 32 bit value.
> + * @mask32: 32 bit mask when using 32 bit value to access device register.
> + */
> +struct cscfg_regval {
> + u32 flags;
> + 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 *regs;
> +};
> +
> +/**
> + * Device / feature matching information.
> + *
> + * 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.
> + * @dev_name: used to match to a particular device instance on the system.
> + *
> + */
> +struct cscfg_match_info {
> + u32 match_flags;
> + /* unique device name (e.g. amba bus name) for specific device match */
> + const char *dev_name;
> +};
> +
> +/**
> + * Descriptor for features referenced by a configuration.
> + *
> + * @name: name of feature to use. Match against the @name in struct
> + * cscfg_feature_desc.
> + * @nr_params: number of parameters the feature has.
> + * @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;
> + int nr_params;
> + struct cscfg_match_info 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;
> + 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 29c83eac3106..481d2b7b6b6f 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);
>
> @@ -1675,13 +1676,22 @@ 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);
> }
> 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);
>
> #endif
> diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c
> new file mode 100644
> index 000000000000..6f89541af7a0
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-syscfg.c
> @@ -0,0 +1,247 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2020 Linaro Limited, All rights reserved.
> + * Author: Mike Leach <mike.leach at 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.
> + */
> +
> +static DEFINE_MUTEX(cscfg_mutex);
> +
> +/* only one of these */
> +static struct cscfg_api_data cscfg_data;
> +
> +/* get reference to cscfg device */
> +struct device *to_device_cscfg(void);
> +
> +/* 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_data.feat_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_data.feat_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_data.config_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 driver. */
> +/* only one of these */
> +static struct cscfg_device *cscfg_dev;
> +
> +/*
> + * We have a separate coresight-config bus for the config device so it does
> + * not appear on the main coresight bus and affect device searches on that bus.
> + */
> +static struct bus_type cscfg_bus_type = {
> + .name = "coresight-config",
> +};
> +
> +struct device *to_device_cscfg(void)
> +{
> + return cscfg_dev ? &cscfg_dev->dev : NULL;
> +}
> +
> +/* Must have a release function or the kernel will complain on module unload */
> +void cscfg_dev_release(struct device *dev)
> +{
> + kfree(cscfg_dev);
> + cscfg_dev = NULL;
> +}
> +
> +int cscfg_create_device(void)
> +{
> + struct device *dev;
> + int err = -ENOMEM;
> +
> + mutex_lock(&cscfg_mutex);
> + if (cscfg_dev) {
> + err = -EINVAL;
> + goto create_dev_exit_unlock;
> + }
> +
> + cscfg_dev = kzalloc(sizeof(struct cscfg_device), GFP_KERNEL);
> + if (!cscfg_dev)
> + goto create_dev_exit_unlock;
> +
> + /* setup the device */
> + dev = to_device_cscfg();
> + dev->bus = &cscfg_bus_type;
> + dev->parent = &platform_bus;
> + dev->release = cscfg_dev_release;
> + dev->init_name = "system_cfg";
> + cscfg_dev->cfg_data = &cscfg_data;
> +
> + 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);
> +}
> +
> +/* driver initialisation */
> +static struct cscfg_driver cs_config_driver = {
> + .drv = {
> + .name = "cs-syscfg-drv",
> + .owner = THIS_MODULE,
> + .suppress_bind_attrs = true,
> + },
> +};
> +
> +int __init cscfg_driver_init(void)
> +{
> + cs_config_driver.drv.bus = &cscfg_bus_type;
> + return driver_register(&cs_config_driver.drv);
> +}
> +
> +void cscfg_driver_exit(void)
> +{
> + driver_unregister(&cs_config_driver.drv);
> +}
> +
> +/* Initialise system config management API */
> +int __init cscfg_init(void)
> +{
> + int err = 0;
> +
> + err = bus_register(&cscfg_bus_type);
> + if (err)
> + return err;
> +
> + err = cscfg_driver_init();
> + if (err)
> + goto exit_bus_unregister;
> +
> + err = cscfg_create_device();
> + if (err)
> + goto exit_drv_unregister;
> +
> + INIT_LIST_HEAD(&cscfg_data.dev_list);
> + INIT_LIST_HEAD(&cscfg_data.feat_list);
> + INIT_LIST_HEAD(&cscfg_data.config_list);
> + cscfg_data.nr_csdev = 0;
> +
> + dev_info(to_device_cscfg(), "CoreSight Configuration manager initialised");
> + return 0;
> +
> +exit_drv_unregister:
> + cscfg_driver_exit();
> +exit_bus_unregister:
> + bus_unregister(&cscfg_bus_type);
> + return err;
> +}
> +
> +void __exit cscfg_exit(void)
> +{
> + cscfg_clear_device();
> + cscfg_driver_exit();
> + bus_unregister(&cscfg_bus_type);
> +}
> diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h
> new file mode 100644
> index 000000000000..5a7896426eab
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-syscfg.h
> @@ -0,0 +1,57 @@
> +/* 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 API data.
> + *
> + * @dev_list: List of other coresight devices registered with this device.
> + * @feat_list: List of features to load into registered devices.
> + * @config_list:List of system configurations to load into registered devices.
> + * @nr_csdev: Number of registered devices with the cscfg system
> + */
> +struct cscfg_api_data {
> + struct list_head dev_list;
struct list_head csdev_desc_list;
And I would rename cscfg_csdev_register to cscfg_csdev_desc in patch 02.
> + struct list_head feat_list;
struct list_head feat_desc_list;
> + struct list_head config_list;
struct list_head config_desc_list;
That way we know exactly what is enqued.
> + int nr_csdev;
> +};
> +
> +/* internal core operations for cscfg */
> +int __init cscfg_init(void);
> +void __exit cscfg_exit(void);
> +
> +/* syscfg external API */
> +int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,
> + struct cscfg_feature_desc **feat_descs);
> +
> +/* system configuration device driver and API */
> +/**
> + * System configuration device.
> + *
> + * Need a device to 'own' some coresight system wide sysfs entries in
> + * perf events etc.
> + *
> + * @dev: The device.
> + * @cfg_data: A reference to the configuration and feature lists
> + */
> +struct cscfg_device {
> + struct device dev;
> + struct cscfg_api_data *cfg_data;
> +};
> +
> +/* basic device driver */
> +struct cscfg_driver {
> + struct device_driver drv;
> +};
> +
> +#endif /* CORESIGHT_SYSCFG_H */
> --
> 2.17.1
>
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