| Message ID | 20210707133003.5414-6-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | CoreSight configuration management; ETM strobing | expand |
On Wed, Jul 07, 2021 at 02:29:58PM +0100, Mike Leach wrote: > Configurations are first activated, then when any coresight device is > enabled, the active configurations are checked and any matching > one is enabled. > > This patch provides the activation / enable API. > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > .../hwtracing/coresight/coresight-config.h | 2 + > .../hwtracing/coresight/coresight-syscfg.c | 197 ++++++++++++++++++ > .../hwtracing/coresight/coresight-syscfg.h | 8 + > include/linux/coresight.h | 4 + > 4 files changed, 211 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h > index 0667581822c1..25eb6c632692 100644 > --- a/drivers/hwtracing/coresight/coresight-config.h > +++ b/drivers/hwtracing/coresight/coresight-config.h > @@ -127,6 +127,7 @@ struct cscfg_feature_desc { > * @nr_total_params: Sum of all parameters declared by used features > * @presets: Array of preset values. > * @event_ea: Extended attribute for perf event value > + * @active_cnt: ref count for activate on this configuration. > * > */ > struct cscfg_config_desc { > @@ -139,6 +140,7 @@ struct cscfg_config_desc { > int nr_total_params; > const u64 *presets; /* nr_presets * nr_total_params */ > struct dev_ext_attribute *event_ea; > + atomic_t active_cnt; > }; > > /** > diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c > index b93f2b4a777e..4e9804875a9b 100644 > --- a/drivers/hwtracing/coresight/coresight-syscfg.c > +++ b/drivers/hwtracing/coresight/coresight-syscfg.c > @@ -282,6 +282,7 @@ static int cscfg_load_config(struct cscfg_config_desc *config_desc) > return err; > > list_add(&config_desc->item, &cscfg_mgr->config_desc_list); > + atomic_set(&config_desc->active_cnt, 0); > return 0; > } > > @@ -468,6 +469,201 @@ void cscfg_unregister_csdev(struct coresight_device *csdev) > } > EXPORT_SYMBOL_GPL(cscfg_unregister_csdev); > > +/** > + * cscfg_csdev_reset_feats - reset features for a CoreSight device. > + * > + * Resets all parameters and register values for any features loaded > + * into @csdev to their default values. > + * > + * @csdev: The CoreSight device. > + */ > +void cscfg_csdev_reset_feats(struct coresight_device *csdev) > +{ > + struct cscfg_feature_csdev *feat_csdev; > + unsigned long flags; > + > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > + if (list_empty(&csdev->feature_csdev_list)) > + goto unlock_exit; > + > + list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) > + cscfg_reset_feat(feat_csdev); > + > +unlock_exit: > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); > +} > +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. > + * > + * 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) > +{ > + 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) { > + /* > + * increment the global active count - control changes to > + * active configurations > + */ > + atomic_inc(&cscfg_mgr->sys_active_cnt); > + > + /* > + * mark the descriptor as active so enable config on a > + * device instance will use it > + */ > + atomic_inc(&config_desc->active_cnt); > + > + err = 0; > + dev_dbg(cscfg_device(), "Activate config %s.\n", config_desc->name); > + break; > + } > + } > + mutex_unlock(&cscfg_mutex); > + > + return err; > +} > +EXPORT_SYMBOL_GPL(cscfg_activate_config); > + > +/** > + * cscfg_deactivate_config - Mark a config descriptor as inactive. > + * > + * Decrement the configuration and global active counts. > + * > + * @cfg_hash: Hash value of the selected configuration name. > + */ > +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; > + } > + } > + mutex_unlock(&cscfg_mutex); > +} > +EXPORT_SYMBOL_GPL(cscfg_deactivate_config); > + > +/** > + * cscfg_csdev_enable_active_config - Enable matching active configuration for device. > + * > + * Enables the configuration selected by @cfg_hash if the configuration is supported > + * on the device and has been activated. > + * > + * If active and supported the CoreSight device @csdev will be programmed with the > + * configuration, using @preset parameters. > + * > + * Should be called before driver hardware enable for the requested device, prior to > + * programming and enabling the physical hardware. > + * > + * @csdev: CoreSight device to program. > + * @cfg_hash: Selector for the configuration. > + * @preset: Preset parameter values to use, 0 for current / default values. > + */ > +int cscfg_csdev_enable_active_config(struct coresight_device *csdev, > + unsigned long cfg_hash, int preset) > +{ > + struct cscfg_config_csdev *config_csdev_active = NULL, *config_csdev_item; > + const struct cscfg_config_desc *config_desc; > + unsigned long flags; > + int err = 0; > + > + /* quickly check global count */ > + if (!atomic_read(&cscfg_mgr->sys_active_cnt)) > + return 0; > + > + /* look for matching config - set in_enable flag if found */ > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > + list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) { > + config_desc = config_csdev_item->config_desc; > + if ((atomic_read(&config_desc->active_cnt)) && > + ((unsigned long)config_desc->event_ea->var == cfg_hash)) { > + config_csdev_active = config_csdev_item; > + csdev->cscfg_in_enable = true; > + break; > + } > + } > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags) In the previous revision the mutex wasn't dropped and cscfg_csdev_enable_config() was called with the mutex held. Any reason for not doing that with the spinlock implemenation? If anything it should be more efficient because the spinlock is on a per csdev basis. It would also keep things simple and avoid adding a new ->cscfg_in_enable field to the coresight_device structure. That last point really concerns me - if holding the spinlock is not possible than a new approach should be considered. Thanks, Mathieu > + > + /* > + * If found, attempt to enable and then set as enabled if no error > + * and in enable flag still set. > + */ > + if (config_csdev_active) { > + /* > + * Call the generic routine that will program up the internal > + * driver structures prior to programming up the hardware. > + * This routine takes the driver spinlock saved in the configs. > + */ > + err = cscfg_csdev_enable_config(config_csdev_active, preset); > + if (!err) { > + /* > + * Successful programming. re-check in_enable flag > + * to avoid potential race with disable config. > + */ > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > + if (csdev->cscfg_in_enable) > + csdev->active_cscfg_ctxt = (void *)config_csdev_active; > + csdev->cscfg_in_enable = false; > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); > + } > + } > + return err; > +} > +EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config); > + > +/** > + * cscfg_csdev_disable_active_config - disable an active config on the device. > + * > + * Disables the active configuration on the CoreSight device @csdev. > + * Disable will save the values of any registers marked in the configurations > + * as save on disable. > + * > + * Should be called after driver hardware disable for the requested device, > + * after disabling the physical hardware and reading back registers. > + * > + * @csdev: The CoreSight device. > + */ > +void cscfg_csdev_disable_active_config(struct coresight_device *csdev) > +{ > + struct cscfg_config_csdev *config_csdev; > + unsigned long flags; > + > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > + csdev->cscfg_in_enable = false; > + config_csdev = (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt; > + csdev->active_cscfg_ctxt = NULL; > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); > + > + if (config_csdev) > + cscfg_csdev_disable_config(config_csdev); > +} > +EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config); > + > /* Initialise system configuration management device. */ > > struct device *cscfg_device(void) > @@ -536,6 +732,7 @@ 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); > + atomic_set(&cscfg_mgr->sys_active_cnt, 0); > > dev_info(cscfg_device(), "CoreSight Configuration manager initialised"); > return 0; > diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h > index 5bcae3b374c6..a52775890670 100644 > --- a/drivers/hwtracing/coresight/coresight-syscfg.h > +++ b/drivers/hwtracing/coresight/coresight-syscfg.h > @@ -24,12 +24,14 @@ > * @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. > + * @sys_active_cnt: Total number of active config descriptor references. > */ > struct cscfg_manager { > struct device dev; > struct list_head csdev_desc_list; > struct list_head feat_desc_list; > struct list_head config_desc_list; > + atomic_t sys_active_cnt; > }; > > /* get reference to dev in cscfg_manager */ > @@ -61,5 +63,11 @@ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, > 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); > +int cscfg_activate_config(unsigned long cfg_hash); > +void cscfg_deactivate_config(unsigned long cfg_hash); > +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); > > #endif /* CORESIGHT_SYSCFG_H */ > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > index 16544ae2b532..e66e1a5fd803 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -223,6 +223,8 @@ struct coresight_sysfs_link { > * @feature_csdev_list: List of complex feature programming added to the device. > * @config_csdev_list: List of system configurations added to the device. > * @cscfg_csdev_lock: Protect the lists of configurations and features. > + * @active_cscfg_ctxt: Context information for current active system configuration. > + * @cscfg_in_enable: Flag to indicate we are in the process of enabling. > */ > struct coresight_device { > struct coresight_platform_data *pdata; > @@ -248,6 +250,8 @@ struct coresight_device { > struct list_head feature_csdev_list; > struct list_head config_csdev_list; > spinlock_t cscfg_csdev_lock; > + void *active_cscfg_ctxt; > + bool cscfg_in_enable; > }; > > /* > -- > 2.17.1 >
On Tue, Jul 20, 2021 at 11:41:06AM -0600, Mathieu Poirier wrote: > On Wed, Jul 07, 2021 at 02:29:58PM +0100, Mike Leach wrote: > > Configurations are first activated, then when any coresight device is > > enabled, the active configurations are checked and any matching > > one is enabled. > > > > This patch provides the activation / enable API. > > > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > > Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > --- > > .../hwtracing/coresight/coresight-config.h | 2 + > > .../hwtracing/coresight/coresight-syscfg.c | 197 ++++++++++++++++++ > > .../hwtracing/coresight/coresight-syscfg.h | 8 + > > include/linux/coresight.h | 4 + > > 4 files changed, 211 insertions(+) > > > > diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h > > index 0667581822c1..25eb6c632692 100644 > > --- a/drivers/hwtracing/coresight/coresight-config.h > > +++ b/drivers/hwtracing/coresight/coresight-config.h > > @@ -127,6 +127,7 @@ struct cscfg_feature_desc { > > * @nr_total_params: Sum of all parameters declared by used features > > * @presets: Array of preset values. > > * @event_ea: Extended attribute for perf event value > > + * @active_cnt: ref count for activate on this configuration. > > * > > */ > > struct cscfg_config_desc { > > @@ -139,6 +140,7 @@ struct cscfg_config_desc { > > int nr_total_params; > > const u64 *presets; /* nr_presets * nr_total_params */ > > struct dev_ext_attribute *event_ea; > > + atomic_t active_cnt; > > }; > > > > /** > > diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c > > index b93f2b4a777e..4e9804875a9b 100644 > > --- a/drivers/hwtracing/coresight/coresight-syscfg.c > > +++ b/drivers/hwtracing/coresight/coresight-syscfg.c > > @@ -282,6 +282,7 @@ static int cscfg_load_config(struct cscfg_config_desc *config_desc) > > return err; > > > > list_add(&config_desc->item, &cscfg_mgr->config_desc_list); > > + atomic_set(&config_desc->active_cnt, 0); > > return 0; > > } > > > > @@ -468,6 +469,201 @@ void cscfg_unregister_csdev(struct coresight_device *csdev) > > } > > EXPORT_SYMBOL_GPL(cscfg_unregister_csdev); > > > > +/** > > + * cscfg_csdev_reset_feats - reset features for a CoreSight device. > > + * > > + * Resets all parameters and register values for any features loaded > > + * into @csdev to their default values. > > + * > > + * @csdev: The CoreSight device. > > + */ > > +void cscfg_csdev_reset_feats(struct coresight_device *csdev) > > +{ > > + struct cscfg_feature_csdev *feat_csdev; > > + unsigned long flags; > > + > > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > > + if (list_empty(&csdev->feature_csdev_list)) > > + goto unlock_exit; > > + > > + list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) > > + cscfg_reset_feat(feat_csdev); > > + > > +unlock_exit: > > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); > > +} > > +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. > > + * > > + * 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) > > +{ > > + 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) { > > + /* > > + * increment the global active count - control changes to > > + * active configurations > > + */ > > + atomic_inc(&cscfg_mgr->sys_active_cnt); > > + > > + /* > > + * mark the descriptor as active so enable config on a > > + * device instance will use it > > + */ > > + atomic_inc(&config_desc->active_cnt); > > + > > + err = 0; > > + dev_dbg(cscfg_device(), "Activate config %s.\n", config_desc->name); > > + break; > > + } > > + } > > + mutex_unlock(&cscfg_mutex); > > + > > + return err; > > +} > > +EXPORT_SYMBOL_GPL(cscfg_activate_config); > > + > > +/** > > + * cscfg_deactivate_config - Mark a config descriptor as inactive. > > + * > > + * Decrement the configuration and global active counts. > > + * > > + * @cfg_hash: Hash value of the selected configuration name. > > + */ > > +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; > > + } > > + } > > + mutex_unlock(&cscfg_mutex); > > +} > > +EXPORT_SYMBOL_GPL(cscfg_deactivate_config); > > + > > +/** > > + * cscfg_csdev_enable_active_config - Enable matching active configuration for device. > > + * > > + * Enables the configuration selected by @cfg_hash if the configuration is supported > > + * on the device and has been activated. > > + * > > + * If active and supported the CoreSight device @csdev will be programmed with the > > + * configuration, using @preset parameters. > > + * > > + * Should be called before driver hardware enable for the requested device, prior to > > + * programming and enabling the physical hardware. > > + * > > + * @csdev: CoreSight device to program. > > + * @cfg_hash: Selector for the configuration. > > + * @preset: Preset parameter values to use, 0 for current / default values. > > + */ > > +int cscfg_csdev_enable_active_config(struct coresight_device *csdev, > > + unsigned long cfg_hash, int preset) > > +{ > > + struct cscfg_config_csdev *config_csdev_active = NULL, *config_csdev_item; > > + const struct cscfg_config_desc *config_desc; > > + unsigned long flags; > > + int err = 0; > > + > > + /* quickly check global count */ > > + if (!atomic_read(&cscfg_mgr->sys_active_cnt)) > > + return 0; > > + > > + /* look for matching config - set in_enable flag if found */ > > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > > + list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) { > > + config_desc = config_csdev_item->config_desc; > > + if ((atomic_read(&config_desc->active_cnt)) && > > + ((unsigned long)config_desc->event_ea->var == cfg_hash)) { > > + config_csdev_active = config_csdev_item; > > + csdev->cscfg_in_enable = true; > > + break; > > + } > > + } > > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags) > > In the previous revision the mutex wasn't dropped and > cscfg_csdev_enable_config() was called with the mutex held. Any reason for not > doing that with the spinlock implemenation? If anything it should be more > efficient because the spinlock is on a per csdev basis. It would also keep > things simple and avoid adding a new ->cscfg_in_enable field to the > coresight_device structure. That last point really concerns me - if holding the > spinlock is not possible than a new approach should be considered. I just read the rational for the above in the change summary... I will have to think further on this - more comments tomorrow. > > Thanks, > Mathieu > > > + > > + /* > > + * If found, attempt to enable and then set as enabled if no error > > + * and in enable flag still set. > > + */ > > + if (config_csdev_active) { > > + /* > > + * Call the generic routine that will program up the internal > > + * driver structures prior to programming up the hardware. > > + * This routine takes the driver spinlock saved in the configs. > > + */ > > + err = cscfg_csdev_enable_config(config_csdev_active, preset); > > + if (!err) { > > + /* > > + * Successful programming. re-check in_enable flag > > + * to avoid potential race with disable config. > > + */ > > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > > + if (csdev->cscfg_in_enable) > > + csdev->active_cscfg_ctxt = (void *)config_csdev_active; > > + csdev->cscfg_in_enable = false; > > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); > > + } > > + } > > + return err; > > +} > > +EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config); > > + > > +/** > > + * cscfg_csdev_disable_active_config - disable an active config on the device. > > + * > > + * Disables the active configuration on the CoreSight device @csdev. > > + * Disable will save the values of any registers marked in the configurations > > + * as save on disable. > > + * > > + * Should be called after driver hardware disable for the requested device, > > + * after disabling the physical hardware and reading back registers. > > + * > > + * @csdev: The CoreSight device. > > + */ > > +void cscfg_csdev_disable_active_config(struct coresight_device *csdev) > > +{ > > + struct cscfg_config_csdev *config_csdev; > > + unsigned long flags; > > + > > + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); > > + csdev->cscfg_in_enable = false; > > + config_csdev = (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt; > > + csdev->active_cscfg_ctxt = NULL; > > + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); > > + > > + if (config_csdev) > > + cscfg_csdev_disable_config(config_csdev); > > +} > > +EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config); > > + > > /* Initialise system configuration management device. */ > > > > struct device *cscfg_device(void) > > @@ -536,6 +732,7 @@ 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); > > + atomic_set(&cscfg_mgr->sys_active_cnt, 0); > > > > dev_info(cscfg_device(), "CoreSight Configuration manager initialised"); > > return 0; > > diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h > > index 5bcae3b374c6..a52775890670 100644 > > --- a/drivers/hwtracing/coresight/coresight-syscfg.h > > +++ b/drivers/hwtracing/coresight/coresight-syscfg.h > > @@ -24,12 +24,14 @@ > > * @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. > > + * @sys_active_cnt: Total number of active config descriptor references. > > */ > > struct cscfg_manager { > > struct device dev; > > struct list_head csdev_desc_list; > > struct list_head feat_desc_list; > > struct list_head config_desc_list; > > + atomic_t sys_active_cnt; > > }; > > > > /* get reference to dev in cscfg_manager */ > > @@ -61,5 +63,11 @@ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, > > 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); > > +int cscfg_activate_config(unsigned long cfg_hash); > > +void cscfg_deactivate_config(unsigned long cfg_hash); > > +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); > > > > #endif /* CORESIGHT_SYSCFG_H */ > > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > > index 16544ae2b532..e66e1a5fd803 100644 > > --- a/include/linux/coresight.h > > +++ b/include/linux/coresight.h > > @@ -223,6 +223,8 @@ struct coresight_sysfs_link { > > * @feature_csdev_list: List of complex feature programming added to the device. > > * @config_csdev_list: List of system configurations added to the device. > > * @cscfg_csdev_lock: Protect the lists of configurations and features. > > + * @active_cscfg_ctxt: Context information for current active system configuration. > > + * @cscfg_in_enable: Flag to indicate we are in the process of enabling. > > */ > > struct coresight_device { > > struct coresight_platform_data *pdata; > > @@ -248,6 +250,8 @@ struct coresight_device { > > struct list_head feature_csdev_list; > > struct list_head config_csdev_list; > > spinlock_t cscfg_csdev_lock; > > + void *active_cscfg_ctxt; > > + bool cscfg_in_enable; > > }; > > > > /* > > -- > > 2.17.1 > >
diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index 0667581822c1..25eb6c632692 100644 --- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -127,6 +127,7 @@ struct cscfg_feature_desc { * @nr_total_params: Sum of all parameters declared by used features * @presets: Array of preset values. * @event_ea: Extended attribute for perf event value + * @active_cnt: ref count for activate on this configuration. * */ struct cscfg_config_desc { @@ -139,6 +140,7 @@ struct cscfg_config_desc { int nr_total_params; const u64 *presets; /* nr_presets * nr_total_params */ struct dev_ext_attribute *event_ea; + atomic_t active_cnt; }; /** diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index b93f2b4a777e..4e9804875a9b 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -282,6 +282,7 @@ static int cscfg_load_config(struct cscfg_config_desc *config_desc) return err; list_add(&config_desc->item, &cscfg_mgr->config_desc_list); + atomic_set(&config_desc->active_cnt, 0); return 0; } @@ -468,6 +469,201 @@ void cscfg_unregister_csdev(struct coresight_device *csdev) } EXPORT_SYMBOL_GPL(cscfg_unregister_csdev); +/** + * cscfg_csdev_reset_feats - reset features for a CoreSight device. + * + * Resets all parameters and register values for any features loaded + * into @csdev to their default values. + * + * @csdev: The CoreSight device. + */ +void cscfg_csdev_reset_feats(struct coresight_device *csdev) +{ + struct cscfg_feature_csdev *feat_csdev; + unsigned long flags; + + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + if (list_empty(&csdev->feature_csdev_list)) + goto unlock_exit; + + list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node) + cscfg_reset_feat(feat_csdev); + +unlock_exit: + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); +} +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. + * + * 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) +{ + 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) { + /* + * increment the global active count - control changes to + * active configurations + */ + atomic_inc(&cscfg_mgr->sys_active_cnt); + + /* + * mark the descriptor as active so enable config on a + * device instance will use it + */ + atomic_inc(&config_desc->active_cnt); + + err = 0; + dev_dbg(cscfg_device(), "Activate config %s.\n", config_desc->name); + break; + } + } + mutex_unlock(&cscfg_mutex); + + return err; +} +EXPORT_SYMBOL_GPL(cscfg_activate_config); + +/** + * cscfg_deactivate_config - Mark a config descriptor as inactive. + * + * Decrement the configuration and global active counts. + * + * @cfg_hash: Hash value of the selected configuration name. + */ +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; + } + } + mutex_unlock(&cscfg_mutex); +} +EXPORT_SYMBOL_GPL(cscfg_deactivate_config); + +/** + * cscfg_csdev_enable_active_config - Enable matching active configuration for device. + * + * Enables the configuration selected by @cfg_hash if the configuration is supported + * on the device and has been activated. + * + * If active and supported the CoreSight device @csdev will be programmed with the + * configuration, using @preset parameters. + * + * Should be called before driver hardware enable for the requested device, prior to + * programming and enabling the physical hardware. + * + * @csdev: CoreSight device to program. + * @cfg_hash: Selector for the configuration. + * @preset: Preset parameter values to use, 0 for current / default values. + */ +int cscfg_csdev_enable_active_config(struct coresight_device *csdev, + unsigned long cfg_hash, int preset) +{ + struct cscfg_config_csdev *config_csdev_active = NULL, *config_csdev_item; + const struct cscfg_config_desc *config_desc; + unsigned long flags; + int err = 0; + + /* quickly check global count */ + if (!atomic_read(&cscfg_mgr->sys_active_cnt)) + return 0; + + /* look for matching config - set in_enable flag if found */ + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) { + config_desc = config_csdev_item->config_desc; + if ((atomic_read(&config_desc->active_cnt)) && + ((unsigned long)config_desc->event_ea->var == cfg_hash)) { + config_csdev_active = config_csdev_item; + csdev->cscfg_in_enable = true; + break; + } + } + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + + /* + * If found, attempt to enable and then set as enabled if no error + * and in enable flag still set. + */ + if (config_csdev_active) { + /* + * Call the generic routine that will program up the internal + * driver structures prior to programming up the hardware. + * This routine takes the driver spinlock saved in the configs. + */ + err = cscfg_csdev_enable_config(config_csdev_active, preset); + if (!err) { + /* + * Successful programming. re-check in_enable flag + * to avoid potential race with disable config. + */ + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + if (csdev->cscfg_in_enable) + csdev->active_cscfg_ctxt = (void *)config_csdev_active; + csdev->cscfg_in_enable = false; + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + } + } + return err; +} +EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config); + +/** + * cscfg_csdev_disable_active_config - disable an active config on the device. + * + * Disables the active configuration on the CoreSight device @csdev. + * Disable will save the values of any registers marked in the configurations + * as save on disable. + * + * Should be called after driver hardware disable for the requested device, + * after disabling the physical hardware and reading back registers. + * + * @csdev: The CoreSight device. + */ +void cscfg_csdev_disable_active_config(struct coresight_device *csdev) +{ + struct cscfg_config_csdev *config_csdev; + unsigned long flags; + + spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + csdev->cscfg_in_enable = false; + config_csdev = (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt; + csdev->active_cscfg_ctxt = NULL; + spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + + if (config_csdev) + cscfg_csdev_disable_config(config_csdev); +} +EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config); + /* Initialise system configuration management device. */ struct device *cscfg_device(void) @@ -536,6 +732,7 @@ 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); + atomic_set(&cscfg_mgr->sys_active_cnt, 0); dev_info(cscfg_device(), "CoreSight Configuration manager initialised"); return 0; diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index 5bcae3b374c6..a52775890670 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -24,12 +24,14 @@ * @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. + * @sys_active_cnt: Total number of active config descriptor references. */ struct cscfg_manager { struct device dev; struct list_head csdev_desc_list; struct list_head feat_desc_list; struct list_head config_desc_list; + atomic_t sys_active_cnt; }; /* get reference to dev in cscfg_manager */ @@ -61,5 +63,11 @@ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, 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); +int cscfg_activate_config(unsigned long cfg_hash); +void cscfg_deactivate_config(unsigned long cfg_hash); +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); #endif /* CORESIGHT_SYSCFG_H */ diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 16544ae2b532..e66e1a5fd803 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -223,6 +223,8 @@ struct coresight_sysfs_link { * @feature_csdev_list: List of complex feature programming added to the device. * @config_csdev_list: List of system configurations added to the device. * @cscfg_csdev_lock: Protect the lists of configurations and features. + * @active_cscfg_ctxt: Context information for current active system configuration. + * @cscfg_in_enable: Flag to indicate we are in the process of enabling. */ struct coresight_device { struct coresight_platform_data *pdata; @@ -248,6 +250,8 @@ struct coresight_device { struct list_head feature_csdev_list; struct list_head config_csdev_list; spinlock_t cscfg_csdev_lock; + void *active_cscfg_ctxt; + bool cscfg_in_enable; }; /*