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Coresight changes for v5.17

Browse Source 
This pull request includes:
 
 - A patch that uses devm_bitmap_zalloc() instead of the open-coded
 equivalent.
 
 - Work to make coresight complex configuration loadable via modules.
 
 - Some coresight documentation updates.
 
 Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
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Merge tag 'coresight-next-v5.17' of gitolite.kernel.org:pub/scm/linux/kernel/git/coresight/linux into char-misc-next

Mathieu writes:

Coresight changes for v5.17

This pull request includes:

- A patch that uses devm_bitmap_zalloc() instead of the open-coded
equivalent.

- Work to make coresight complex configuration loadable via modules.

- Some coresight documentation updates.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

* tag 'coresight-next-v5.17' of gitolite.kernel.org:pub/scm/linux/kernel/git/coresight/linux:
  coresight: core: Fix typo in a comment
  Documentation: coresight: Update coresight configuration docs
  coresight: configfs: Allow configfs to activate configuration
  coresight: syscfg: Example CoreSight configuration loadable module
  coresight: syscfg: Update load API for config loadable modules
  coresight: configuration: Update API to permit dynamic load/unload
  coresight: configuration: Update API to introduce load owner concept
  Documentation: coresight: Fix documentation issue
  coresight: Use devm_bitmap_zalloc when applicable
This commit is contained in:
Greg Kroah-Hartman 2021-12-21 10:07:07 +01:00
commit fdcee305c0
15 changed files with 595 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

78
Documentation/trace/coresight/coresight-config.rst
View File

@ -155,14 +155,14 @@ follows::
autofdo
$ cd autofdo/
$ ls
description preset1 preset3 preset5 preset7 preset9
feature_refs preset2 preset4 preset6 preset8
description feature_refs preset1 preset3 preset5 preset7 preset9
enable preset preset2 preset4 preset6 preset8
$ cat description
Setup ETMs with strobing for autofdo
$ cat feature_refs
strobing
Each preset declared has a preset<n> subdirectory declared. The values for
Each preset declared has a 'preset<n>' subdirectory declared. The values for
the preset can be examined::
$ cat preset1/values
@ -170,6 +170,9 @@ the preset can be examined::
$ cat preset2/values
strobing.window = 0x1388 strobing.period = 0x4
The 'enable' and 'preset' files allow the control of a configuration when
using CoreSight with sysfs.
The features referenced by the configuration can be examined in the features
directory::
@ -211,19 +214,13 @@ also declared in the perf 'cs_etm' event infrastructure so that they can
be selected when running trace under perf::
$ ls /sys/devices/cs_etm
configurations format perf_event_mux_interval_ms sinks type
events nr_addr_filters power
cpu0 cpu2 events nr_addr_filters power subsystem uevent
cpu1 cpu3 format perf_event_mux_interval_ms sinks type
Key directories here are 'configurations' - which lists the loaded
configurations, and 'events' - a generic perf directory which allows
selection on the perf command line.::
The key directory here is 'events' - a generic perf directory which allows
selection on the perf command line. As with the sinks entries, this provides
a hash of the configuration name.
$ ls configurations/
autofdo
$ cat configurations/autofdo
0xa7c3dddd
As with the sinks entries, this provides a hash of the configuration name.
The entry in the 'events' directory uses perfs built in syntax generator
to substitute the syntax for the name when evaluating the command::
@ -242,3 +239,56 @@ A preset to override the current parameter values can also be selected::
When configurations are selected in this way, then the trace sink used is
automatically selected.
Using Configurations in sysfs
=============================
Coresight can be controlled using sysfs. When this is in use then a configuration
can be made active for the devices that are used in the sysfs session.
In a configuration there are 'enable' and 'preset' files.
To enable a configuration for use with sysfs::
$ cd configurations/autofdo
$ echo 1 > enable
This will then use any default parameter values in the features - which can be
adjusted as described above.
To use a preset<n> set of parameter values::
$ echo 3 > preset
This will select preset3 for the configuration.
The valid values for preset are 0 - to deselect presets, and any value of
<n> where a preset<n> sub-directory is present.
Note that the active sysfs configuration is a global parameter, therefore
only a single configuration can be active for sysfs at any one time.
Attempting to enable a second configuration will result in an error.
Additionally, attempting to disable the configuration while in use will
also result in an error.
The use of the active configuration by sysfs is independent of the configuration
used in perf.
Creating and Loading Custom Configurations
==========================================
Custom configurations and / or features can be dynamically loaded into the
system by using a loadable module.
An example of a custom configuration is found in ./samples/coresight.
This creates a new configuration that uses the existing built in
strobing feature, but provides a different set of presets.
When the module is loaded, then the configuration appears in the configfs
file system and is selectable in the same way as the built in configuration
described above.
Configurations can use previously loaded features. The system will ensure
that it is not possible to unload a feature that is currently in use, by
enforcing the unload order as the strict reverse of the load order.

1
MAINTAINERS
View File

@ -1890,6 +1890,7 @@ F: Documentation/trace/coresight/*
F: drivers/hwtracing/coresight/*
F: include/dt-bindings/arm/coresight-cti-dt.h
F: include/linux/coresight*
F: samples/coresight/*
F: tools/perf/arch/arm/util/auxtrace.c
F: tools/perf/arch/arm/util/cs-etm.c
F: tools/perf/arch/arm/util/cs-etm.h

9
drivers/hwtracing/coresight/coresight-cfg-preload.c
View File

@ -24,8 +24,13 @@ static struct cscfg_config_desc *preload_cfgs[] = {
NULL
};
static struct cscfg_load_owner_info preload_owner = {
.type = CSCFG_OWNER_PRELOAD,
};
/* preload called on initialisation */
int cscfg_preload(void)
int cscfg_preload(void *owner_handle)
{
return cscfg_load_config_sets(preload_cfgs, preload_feats);
preload_owner.owner_handle = owner_handle;
return cscfg_load_config_sets(preload_cfgs, preload_feats, &preload_owner);
}

9
drivers/hwtracing/coresight/coresight-config.h
View File

@ -97,6 +97,8 @@ struct cscfg_regval_desc {
* @params_desc: array of parameters used.
* @nr_regs: number of registers used.
* @regs_desc: array of registers used.
* @load_owner: handle to load owner for dynamic load and unload of features.
* @fs_group: reference to configfs group for dynamic unload.
*/
struct cscfg_feature_desc {
const char *name;
@ -107,6 +109,8 @@ struct cscfg_feature_desc {
struct cscfg_parameter_desc *params_desc;
int nr_regs;
struct cscfg_regval_desc *regs_desc;
void *load_owner;
struct config_group *fs_group;
};
/**
@ -128,7 +132,8 @@ struct cscfg_feature_desc {
* @presets: Array of preset values.
* @event_ea: Extended attribute for perf event value
* @active_cnt: ref count for activate on this configuration.
*
* @load_owner: handle to load owner for dynamic load and unload of configs.
* @fs_group: reference to configfs group for dynamic unload.
*/
struct cscfg_config_desc {
const char *name;
@ -141,6 +146,8 @@ struct cscfg_config_desc {
const u64 *presets; /* nr_presets * nr_total_params */
struct dev_ext_attribute *event_ea;
atomic_t active_cnt;
void *load_owner;
struct config_group *fs_group;
};
/**

2
drivers/hwtracing/coresight/coresight-core.c
View File

@ -729,7 +729,7 @@ static inline void coresight_put_ref(struct coresight_device *csdev)
* coresight_grab_device - Power up this device and any of the helper
* devices connected to it for trace operation. Since the helper devices
* don't appear on the trace path, they should be handled along with the
* the master device.
* master device.
*/
static int coresight_grab_device(struct coresight_device *csdev)
{

11
drivers/hwtracing/coresight/coresight-etm4x-core.c
View File

@ -722,7 +722,16 @@ static int etm4_enable_sysfs(struct coresight_device *csdev)
{
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
struct etm4_enable_arg arg = { };
int ret;
unsigned long cfg_hash;
int ret, preset;
/* enable any config activated by configfs */
cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
if (cfg_hash) {
ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
if (ret)
return ret;
}
spin_lock(&drvdata->spinlock);

10
drivers/hwtracing/coresight/coresight-stm.c
View File

@ -856,13 +856,11 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id)
{
int ret;
void __iomem *base;
unsigned long *guaranteed;
struct device *dev = &adev->dev;
struct coresight_platform_data *pdata = NULL;
struct stm_drvdata *drvdata;
struct resource *res = &adev->res;
struct resource ch_res;
size_t bitmap_size;
struct coresight_desc desc = { 0 };
desc.name = coresight_alloc_device_name(&stm_devs, dev);
@ -904,12 +902,10 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id)
else
drvdata->numsp = stm_num_stimulus_port(drvdata);
bitmap_size = BITS_TO_LONGS(drvdata->numsp) * sizeof(long);
guaranteed = devm_kzalloc(dev, bitmap_size, GFP_KERNEL);
if (!guaranteed)
drvdata->chs.guaranteed = devm_bitmap_zalloc(dev, drvdata->numsp,
GFP_KERNEL);
if (!drvdata->chs.guaranteed)
return -ENOMEM;
drvdata->chs.guaranteed = guaranteed;
spin_lock_init(&drvdata->spinlock);

87
drivers/hwtracing/coresight/coresight-syscfg-configfs.c
View File

@ -6,6 +6,7 @@
#include <linux/configfs.h>
#include "coresight-config.h"
#include "coresight-syscfg-configfs.h"
/* create a default ci_type. */
@ -87,9 +88,75 @@ static ssize_t cscfg_cfg_values_show(struct config_item *item, char *page)
}
CONFIGFS_ATTR_RO(cscfg_cfg_, values);
static ssize_t cscfg_cfg_enable_show(struct config_item *item, char *page)
{
struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
struct cscfg_fs_config, group);
return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->active);
}
static ssize_t cscfg_cfg_enable_store(struct config_item *item,
const char *page, size_t count)
{
struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
struct cscfg_fs_config, group);
int err;
bool val;
err = kstrtobool(page, &val);
if (!err)
err = cscfg_config_sysfs_activate(fs_config->config_desc, val);
if (!err) {
fs_config->active = val;
if (val)
cscfg_config_sysfs_set_preset(fs_config->preset);
}
return err ? err : count;
}
CONFIGFS_ATTR(cscfg_cfg_, enable);
static ssize_t cscfg_cfg_preset_show(struct config_item *item, char *page)
{
struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
struct cscfg_fs_config, group);
return scnprintf(page, PAGE_SIZE, "%d\n", fs_config->preset);
}
static ssize_t cscfg_cfg_preset_store(struct config_item *item,
const char *page, size_t count)
{
struct cscfg_fs_config *fs_config = container_of(to_config_group(item),
struct cscfg_fs_config, group);
int preset, err;
err = kstrtoint(page, 0, &preset);
if (!err) {
/*
* presets start at 1, and go up to max (15),
* but the config may provide fewer.
*/
if ((preset < 1) || (preset > fs_config->config_desc->nr_presets))
err = -EINVAL;
}
if (!err) {
/* set new value */
fs_config->preset = preset;
/* set on system if active */
if (fs_config->active)
cscfg_config_sysfs_set_preset(fs_config->preset);
}
return err ? err : count;
}
CONFIGFS_ATTR(cscfg_cfg_, preset);
static struct configfs_attribute *cscfg_config_view_attrs[] = {
&cscfg_cfg_attr_description,
&cscfg_cfg_attr_feature_refs,
&cscfg_cfg_attr_enable,
&cscfg_cfg_attr_preset,
NULL,
};
@ -334,9 +401,19 @@ int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc)
if (IS_ERR(new_group))
return PTR_ERR(new_group);
err = configfs_register_group(&cscfg_configs_grp, new_group);
if (!err)
config_desc->fs_group = new_group;
return err;
}
void cscfg_configfs_del_config(struct cscfg_config_desc *config_desc)
{
if (config_desc->fs_group) {
configfs_unregister_group(config_desc->fs_group);
config_desc->fs_group = NULL;
}
}
static struct config_item_type cscfg_features_type = {
.ct_owner = THIS_MODULE,
};
@ -358,9 +435,19 @@ int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc)
if (IS_ERR(new_group))
return PTR_ERR(new_group);
err = configfs_register_group(&cscfg_features_grp, new_group);
if (!err)
feat_desc->fs_group = new_group;
return err;
}
void cscfg_configfs_del_feature(struct cscfg_feature_desc *feat_desc)
{
if (feat_desc->fs_group) {
configfs_unregister_group(feat_desc->fs_group);
feat_desc->fs_group = NULL;
}
}
int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr)
{
struct configfs_subsystem *subsys;

4
drivers/hwtracing/coresight/coresight-syscfg-configfs.h
View File

@ -15,6 +15,8 @@
struct cscfg_fs_config {
struct cscfg_config_desc *config_desc;
struct config_group group;
bool active;
int preset;
};
/* container for feature view */
@ -41,5 +43,7 @@ int cscfg_configfs_init(struct cscfg_manager *cscfg_mgr);
void cscfg_configfs_release(struct cscfg_manager *cscfg_mgr);
int cscfg_configfs_add_config(struct cscfg_config_desc *config_desc);
int cscfg_configfs_add_feature(struct cscfg_feature_desc *feat_desc);
void cscfg_configfs_del_config(struct cscfg_config_desc *config_desc);
void cscfg_configfs_del_feature(struct cscfg_feature_desc *feat_desc);
#endif /* CORESIGHT_SYSCFG_CONFIGFS_H */

315
drivers/hwtracing/coresight/coresight-syscfg.c
View File

@ -250,6 +250,13 @@ static int cscfg_check_feat_for_cfg(struct cscfg_config_desc *config_desc)
static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc)
{
int err;
struct cscfg_feature_desc *feat_desc_exist;
/* new feature must have unique name */
list_for_each_entry(feat_desc_exist, &cscfg_mgr->feat_desc_list, item) {
if (!strcmp(feat_desc_exist->name, feat_desc->name))
return -EEXIST;
}
/* add feature to any matching registered devices */
err = cscfg_add_feat_to_csdevs(feat_desc);
@ -267,6 +274,13 @@ static int cscfg_load_feat(struct cscfg_feature_desc *feat_desc)
static int cscfg_load_config(struct cscfg_config_desc *config_desc)
{
int err;
struct cscfg_config_desc *config_desc_exist;
/* new configuration must have a unique name */
list_for_each_entry(config_desc_exist, &cscfg_mgr->config_desc_list, item) {
if (!strcmp(config_desc_exist->name, config_desc->name))
return -EEXIST;
}
/* validate features are present */
err = cscfg_check_feat_for_cfg(config_desc);
@ -354,6 +368,92 @@ unlock_exit:
return err;
}
/*
* Conditionally up reference count on owner to prevent unload.
*
* module loaded configs need to be locked in to prevent premature unload.
*/
static int cscfg_owner_get(struct cscfg_load_owner_info *owner_info)
{
if ((owner_info->type == CSCFG_OWNER_MODULE) &&
(!try_module_get(owner_info->owner_handle)))
return -EINVAL;
return 0;
}
/* conditionally lower ref count on an owner */
static void cscfg_owner_put(struct cscfg_load_owner_info *owner_info)
{
if (owner_info->type == CSCFG_OWNER_MODULE)
module_put(owner_info->owner_handle);
}
static void cscfg_remove_owned_csdev_configs(struct coresight_device *csdev, void *load_owner)
{
struct cscfg_config_csdev *config_csdev, *tmp;
if (list_empty(&csdev->config_csdev_list))
return;
list_for_each_entry_safe(config_csdev, tmp, &csdev->config_csdev_list, node) {
if (config_csdev->config_desc->load_owner == load_owner)
list_del(&config_csdev->node);
}
}
static void cscfg_remove_owned_csdev_features(struct coresight_device *csdev, void *load_owner)
{
struct cscfg_feature_csdev *feat_csdev, *tmp;
if (list_empty(&csdev->feature_csdev_list))
return;
list_for_each_entry_safe(feat_csdev, tmp, &csdev->feature_csdev_list, node) {
if (feat_csdev->feat_desc->load_owner == load_owner)
list_del(&feat_csdev->node);
}
}
/*
* removal is relatively easy - just remove from all lists, anything that
* matches the owner. Memory for the descriptors will be managed by the owner,
* memory for the csdev items is devm_ allocated with the individual csdev
* devices.
*/
static void cscfg_unload_owned_cfgs_feats(void *load_owner)
{
struct cscfg_config_desc *config_desc, *cfg_tmp;
struct cscfg_feature_desc *feat_desc, *feat_tmp;
struct cscfg_registered_csdev *csdev_item;
/* remove from each csdev instance feature and config lists */
list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) {
/*
* for each csdev, check the loaded lists and remove if
* referenced descriptor is owned
*/
cscfg_remove_owned_csdev_configs(csdev_item->csdev, load_owner);
cscfg_remove_owned_csdev_features(csdev_item->csdev, load_owner);
}
/* remove from the config descriptor lists */
list_for_each_entry_safe(config_desc, cfg_tmp, &cscfg_mgr->config_desc_list, item) {
if (config_desc->load_owner == load_owner) {
cscfg_configfs_del_config(config_desc);
etm_perf_del_symlink_cscfg(config_desc);
list_del(&config_desc->item);
}
}
/* remove from the feature descriptor lists */
list_for_each_entry_safe(feat_desc, feat_tmp, &cscfg_mgr->feat_desc_list, item) {
if (feat_desc->load_owner == load_owner) {
cscfg_configfs_del_feature(feat_desc);
list_del(&feat_desc->item);
}
}
}
/**
* cscfg_load_config_sets - API function to load feature and config sets.
*
@ -361,13 +461,22 @@ unlock_exit:
* descriptors and load into the system.
* Features are loaded first to ensure configuration dependencies can be met.
*
* To facilitate dynamic loading and unloading, features and configurations
* have a "load_owner", to allow later unload by the same owner. An owner may
* be a loadable module or configuration dynamically created via configfs.
* As later loaded configurations can use earlier loaded features, creating load
* dependencies, a load order list is maintained. Unload is strictly in the
* reverse order to load.
*
* @config_descs: 0 terminated array of configuration descriptors.
* @feat_descs: 0 terminated array of feature descriptors.
* @owner_info: Information on the owner of this set.
*/
int cscfg_load_config_sets(struct cscfg_config_desc **config_descs,
struct cscfg_feature_desc **feat_descs)
struct cscfg_feature_desc **feat_descs,
struct cscfg_load_owner_info *owner_info)
{
int err, i = 0;
int err = 0, i = 0;
mutex_lock(&cscfg_mutex);
@ -380,8 +489,10 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs,
if (err) {
pr_err("coresight-syscfg: Failed to load feature %s\n",
feat_descs[i]->name);
cscfg_unload_owned_cfgs_feats(owner_info);
goto exit_unlock;
}
feat_descs[i]->load_owner = owner_info;
i++;
}
}
@ -396,18 +507,86 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs,
if (err) {
pr_err("coresight-syscfg: Failed to load configuration %s\n",
config_descs[i]->name);
cscfg_unload_owned_cfgs_feats(owner_info);
goto exit_unlock;
}
config_descs[i]->load_owner = owner_info;
i++;
}
}
/* add the load owner to the load order list */
list_add_tail(&owner_info->item, &cscfg_mgr->load_order_list);
if (!list_is_singular(&cscfg_mgr->load_order_list)) {
/* lock previous item in load order list */
err = cscfg_owner_get(list_prev_entry(owner_info, item));
if (err) {
cscfg_unload_owned_cfgs_feats(owner_info);
list_del(&owner_info->item);
}
}
exit_unlock:
mutex_unlock(&cscfg_mutex);
return err;
}
EXPORT_SYMBOL_GPL(cscfg_load_config_sets);
/**
* cscfg_unload_config_sets - unload a set of configurations by owner.
*
* Dynamic unload of configuration and feature sets is done on the basis of
* the load owner of that set. Later loaded configurations can depend on
* features loaded earlier.
*
* Therefore, unload is only possible if:-
* 1) no configurations are active.
* 2) the set being unloaded was the last to be loaded to maintain dependencies.
*
* @owner_info: Information on owner for set being unloaded.
*/
int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info)
{
int err = 0;
struct cscfg_load_owner_info *load_list_item = NULL;
mutex_lock(&cscfg_mutex);
/* cannot unload if anything is active */
if (atomic_read(&cscfg_mgr->sys_active_cnt)) {
err = -EBUSY;
goto exit_unlock;
}
/* cannot unload if not last loaded in load order */
if (!list_empty(&cscfg_mgr->load_order_list)) {
load_list_item = list_last_entry(&cscfg_mgr->load_order_list,
struct cscfg_load_owner_info, item);
if (load_list_item != owner_info)
load_list_item = NULL;
}
if (!load_list_item) {
err = -EINVAL;
goto exit_unlock;
}
/* unload all belonging to load_owner */
cscfg_unload_owned_cfgs_feats(owner_info);
/* remove from load order list */
if (!list_is_singular(&cscfg_mgr->load_order_list)) {
/* unlock previous item in load order list */
cscfg_owner_put(list_prev_entry(owner_info, item));
}
list_del(&owner_info->item);
exit_unlock:
mutex_unlock(&cscfg_mutex);
return err;
}
EXPORT_SYMBOL_GPL(cscfg_unload_config_sets);
/* Handle coresight device registration and add configs and features to devices */
/* iterate through config lists and load matching configs to device */
@ -566,32 +745,26 @@ unlock_exit:
}
EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats);
/**
* cscfg_activate_config - Mark a configuration descriptor as active.
*
* This will be seen when csdev devices are enabled in the system.
* Only activated configurations can be enabled on individual devices.
* Activation protects the configuration from alteration or removal while
* active.
*
* Selection by hash value - generated from the configuration name when it
* was loaded and added to the cs_etm/configurations file system for selection
* by perf.
/*
* This activate configuration for either perf or sysfs. Perf can have multiple
* active configs, selected per event, sysfs is limited to one.
*
* Increments the configuration descriptor active count and the global active
* count.
*
* @cfg_hash: Hash value of the selected configuration name.
*/
int cscfg_activate_config(unsigned long cfg_hash)
static int _cscfg_activate_config(unsigned long cfg_hash)
{
struct cscfg_config_desc *config_desc;
int err = -EINVAL;
mutex_lock(&cscfg_mutex);
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {
/* must ensure that config cannot be unloaded in use */
err = cscfg_owner_get(config_desc->load_owner);
if (err)
break;
/*
* increment the global active count - control changes to
* active configurations
@ -609,6 +782,101 @@ int cscfg_activate_config(unsigned long cfg_hash)
break;
}
}
return err;
}
static void _cscfg_deactivate_config(unsigned long cfg_hash)
{
struct cscfg_config_desc *config_desc;
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {
atomic_dec(&config_desc->active_cnt);
atomic_dec(&cscfg_mgr->sys_active_cnt);
cscfg_owner_put(config_desc->load_owner);
dev_dbg(cscfg_device(), "Deactivate config %s.\n", config_desc->name);
break;
}
}
}
/*
* called from configfs to set/clear the active configuration for use when
* using sysfs to control trace.
*/
int cscfg_config_sysfs_activate(struct cscfg_config_desc *config_desc, bool activate)
{
unsigned long cfg_hash;
int err = 0;
mutex_lock(&cscfg_mutex);
cfg_hash = (unsigned long)config_desc->event_ea->var;
if (activate) {
/* cannot be a current active value to activate this */
if (cscfg_mgr->sysfs_active_config) {
err = -EBUSY;
goto exit_unlock;
}
err = _cscfg_activate_config(cfg_hash);
if (!err)
cscfg_mgr->sysfs_active_config = cfg_hash;
} else {
/* disable if matching current value */
if (cscfg_mgr->sysfs_active_config == cfg_hash) {
_cscfg_deactivate_config(cfg_hash);
cscfg_mgr->sysfs_active_config = 0;
} else
err = -EINVAL;
}
exit_unlock:
mutex_unlock(&cscfg_mutex);
return err;
}
/* set the sysfs preset value */
void cscfg_config_sysfs_set_preset(int preset)
{
mutex_lock(&cscfg_mutex);
cscfg_mgr->sysfs_active_preset = preset;
mutex_unlock(&cscfg_mutex);
}
/*
* Used by a device to get the config and preset selected as active in configfs,
* when using sysfs to control trace.
*/
void cscfg_config_sysfs_get_active_cfg(unsigned long *cfg_hash, int *preset)
{
mutex_lock(&cscfg_mutex);
*preset = cscfg_mgr->sysfs_active_preset;
*cfg_hash = cscfg_mgr->sysfs_active_config;
mutex_unlock(&cscfg_mutex);
}
EXPORT_SYMBOL_GPL(cscfg_config_sysfs_get_active_cfg);
/**
* cscfg_activate_config - Mark a configuration descriptor as active.
*
* This will be seen when csdev devices are enabled in the system.
* Only activated configurations can be enabled on individual devices.
* Activation protects the configuration from alteration or removal while
* active.
*
* Selection by hash value - generated from the configuration name when it
* was loaded and added to the cs_etm/configurations file system for selection
* by perf.
*
* @cfg_hash: Hash value of the selected configuration name.
*/
int cscfg_activate_config(unsigned long cfg_hash)
{
int err = 0;
mutex_lock(&cscfg_mutex);
err = _cscfg_activate_config(cfg_hash);
mutex_unlock(&cscfg_mutex);
return err;
@ -624,18 +892,8 @@ EXPORT_SYMBOL_GPL(cscfg_activate_config);
*/
void cscfg_deactivate_config(unsigned long cfg_hash)
{
struct cscfg_config_desc *config_desc;
mutex_lock(&cscfg_mutex);
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {
atomic_dec(&config_desc->active_cnt);
atomic_dec(&cscfg_mgr->sys_active_cnt);
dev_dbg(cscfg_device(), "Deactivate config %s.\n", config_desc->name);
break;
}
}
_cscfg_deactivate_config(cfg_hash);
mutex_unlock(&cscfg_mutex);
}
EXPORT_SYMBOL_GPL(cscfg_deactivate_config);
@ -827,10 +1085,11 @@ int __init cscfg_init(void)
INIT_LIST_HEAD(&cscfg_mgr->csdev_desc_list);
INIT_LIST_HEAD(&cscfg_mgr->feat_desc_list);
INIT_LIST_HEAD(&cscfg_mgr->config_desc_list);
INIT_LIST_HEAD(&cscfg_mgr->load_order_list);
atomic_set(&cscfg_mgr->sys_active_cnt, 0);
/* preload built-in configurations */
err = cscfg_preload();
err = cscfg_preload(THIS_MODULE);
if (err)
goto exit_err;

39
drivers/hwtracing/coresight/coresight-syscfg.h
View File

@ -25,16 +25,22 @@
* @csdev_desc_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.
* @load_order_list: Ordered list of owners for dynamically loaded configurations.
* @sys_active_cnt: Total number of active config descriptor references.
* @cfgfs_subsys: configfs subsystem used to manage configurations.
* @sysfs_active_config:Active config hash used if CoreSight controlled from sysfs.
* @sysfs_active_preset:Active preset index used if CoreSight controlled from sysfs.
*/
struct cscfg_manager {
struct device dev;
struct list_head csdev_desc_list;
struct list_head feat_desc_list;
struct list_head config_desc_list;
struct list_head load_order_list;
atomic_t sys_active_cnt;
struct configfs_subsystem cfgfs_subsys;
u32 sysfs_active_config;
int sysfs_active_preset;
};
/* get reference to dev in cscfg_manager */
@ -56,18 +62,44 @@ struct cscfg_registered_csdev {
struct list_head item;
};
/* owner types for loading and unloading of config and feature sets */
enum cscfg_load_owner_type {
CSCFG_OWNER_PRELOAD,
CSCFG_OWNER_MODULE,
};
/**
* Load item - item to add to the load order list allowing dynamic load and
* unload of configurations and features. Caller loading a config
* set provides a context handle for unload. API ensures that
* items unloaded strictly in reverse order from load to ensure
* dependencies are respected.
*
* @item: list entry for load order list.
* @type: type of owner - allows interpretation of owner_handle.
* @owner_handle: load context - handle for owner of loaded configs.
*/
struct cscfg_load_owner_info {
struct list_head item;
int type;
void *owner_handle;
};
/* internal core operations for cscfg */
int __init cscfg_init(void);
void cscfg_exit(void);
int cscfg_preload(void);
int cscfg_preload(void *owner_handle);
const struct cscfg_feature_desc *cscfg_get_named_feat_desc(const char *name);
int cscfg_update_feat_param_val(struct cscfg_feature_desc *feat_desc,
int param_idx, u64 value);
int cscfg_config_sysfs_activate(struct cscfg_config_desc *cfg_desc, bool activate);
void cscfg_config_sysfs_set_preset(int preset);
/* syscfg manager external API */
int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs,
struct cscfg_feature_desc **feat_descs);
struct cscfg_feature_desc **feat_descs,
struct cscfg_load_owner_info *owner_info);
int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info);
int cscfg_register_csdev(struct coresight_device *csdev, u32 match_flags,
struct cscfg_csdev_feat_ops *ops);
void cscfg_unregister_csdev(struct coresight_device *csdev);
@ -77,5 +109,6 @@ void cscfg_csdev_reset_feats(struct coresight_device *csdev);
int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
unsigned long cfg_hash, int preset);
void cscfg_csdev_disable_active_config(struct coresight_device *csdev);
void cscfg_config_sysfs_get_active_cfg(unsigned long *cfg_hash, int *preset);
#endif /* CORESIGHT_SYSCFG_H */

9
samples/Kconfig
View File

@ -241,6 +241,15 @@ config SAMPLE_WATCH_QUEUE
Build example userspace program to use the new mount_notify(),
sb_notify() syscalls and the KEYCTL_WATCH_KEY keyctl() function.
config SAMPLE_CORESIGHT_SYSCFG
tristate "Build example loadable module for CoreSight config"
depends on CORESIGHT && m
help
Build an example loadable module that adds new CoreSight features
and configuration using the CoreSight system configuration API.
This demonstrates how a user may create their own CoreSight
configurations and easily load them into the system at runtime.
endif # SAMPLES
config HAVE_SAMPLE_FTRACE_DIRECT

1
samples/Makefile
View File

@ -32,3 +32,4 @@ obj-$(CONFIG_SAMPLE_INTEL_MEI) += mei/
subdir-$(CONFIG_SAMPLE_WATCHDOG) += watchdog
subdir-$(CONFIG_SAMPLE_WATCH_QUEUE) += watch_queue
obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak/
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight/

4
samples/coresight/Makefile Normal file
View File

@ -0,0 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight-cfg-sample.o
ccflags-y += -I$(srctree)/drivers/hwtracing/coresight

73
samples/coresight/coresight-cfg-sample.c Normal file
View File

@ -0,0 +1,73 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright(C) 2020 Linaro Limited. All rights reserved.
* Author: Mike Leach <mike.leach@linaro.org>
*/
#include "coresight-config.h"
#include "coresight-syscfg.h"
/* create an alternate autofdo configuration */
/* we will provide 4 sets of preset parameter values */
#define AFDO2_NR_PRESETS 4
/* the total number of parameters in used features - strobing has 2 */
#define AFDO2_NR_PARAM_SUM 2
static const char *afdo2_ref_names[] = {
"strobing",
};
/*
* set of presets leaves strobing window constant while varying period to allow
* experimentation with mark / space ratios for various workloads
*/
static u64 afdo2_presets[AFDO2_NR_PRESETS][AFDO2_NR_PARAM_SUM] = {
{ 1000, 100 },
{ 1000, 1000 },
{ 1000, 5000 },
{ 1000, 10000 },
};
struct cscfg_config_desc afdo2 = {
.name = "autofdo2",
.description = "Setup ETMs with strobing for autofdo\n"
"Supplied presets allow experimentation with mark-space ratio for various loads\n",
.nr_feat_refs = ARRAY_SIZE(afdo2_ref_names),
.feat_ref_names = afdo2_ref_names,
.nr_presets = AFDO2_NR_PRESETS,
.nr_total_params = AFDO2_NR_PARAM_SUM,
.presets = &afdo2_presets[0][0],
};
static struct cscfg_feature_desc *sample_feats[] = {
NULL
};
static struct cscfg_config_desc *sample_cfgs[] = {
&afdo2,
NULL
};
static struct cscfg_load_owner_info mod_owner = {
.type = CSCFG_OWNER_MODULE,
.owner_handle = THIS_MODULE,
};
/* module init and exit - just load and unload configs */
static int __init cscfg_sample_init(void)
{
return cscfg_load_config_sets(sample_cfgs, sample_feats, &mod_owner);
}
static void __exit cscfg_sample_exit(void)
{
cscfg_unload_config_sets(&mod_owner);
}
module_init(cscfg_sample_init);
module_exit(cscfg_sample_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Mike Leach <mike.leach@linaro.org>");
MODULE_DESCRIPTION("CoreSight Syscfg Example");