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coresight: change coresight_device lock type to raw_spinlock_t

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coresight_device->cscfg_csdev_lock can be held during __schedule()
by perf_event_task_sched_out()/in().

Since coresight->cscfg_csdev_lock type is spinlock_t and
perf_event_task_sched_out()/in() is called after acquiring rq_lock,
which is raw_spinlock_t (an unsleepable lock),
this poses an issue in PREEMPT_RT kernel where spinlock_t is sleepable.

To address this, change type of coresight_device->cscfg_csdev_lock
from spinlock_t to raw_spinlock_t.

Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250306121110.1647948-2-yeoreum.yun@arm.com
This commit is contained in:
Yeoreum Yun 2025-03-06 12:11:02 +00:00 committed by Suzuki K Poulose
parent ab37128ad5
commit 26f060c106
2 changed files with 14 additions and 14 deletions
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26
drivers/hwtracing/coresight/coresight-syscfg.c
View File

@ -89,9 +89,9 @@ static int cscfg_add_csdev_cfg(struct coresight_device *csdev,
}
/* if matched features, add config to device.*/
if (config_csdev) {
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
list_add(&config_csdev->node, &csdev->config_csdev_list);
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
}
return 0;
@ -194,9 +194,9 @@ static int cscfg_load_feat_csdev(struct coresight_device *csdev,
/* add to internal csdev feature list & initialise using reset call */
cscfg_reset_feat(feat_csdev);
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
list_add(&feat_csdev->node, &csdev->feature_csdev_list);
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
return 0;
}
@ -765,7 +765,7 @@ static int cscfg_list_add_csdev(struct coresight_device *csdev,
INIT_LIST_HEAD(&csdev->feature_csdev_list);
INIT_LIST_HEAD(&csdev->config_csdev_list);
spin_lock_init(&csdev->cscfg_csdev_lock);
raw_spin_lock_init(&csdev->cscfg_csdev_lock);
return 0;
}
@ -855,7 +855,7 @@ 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);
raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
if (list_empty(&csdev->feature_csdev_list))
goto unlock_exit;
@ -863,7 +863,7 @@ void cscfg_csdev_reset_feats(struct coresight_device *csdev)
cscfg_reset_feat(feat_csdev);
unlock_exit:
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
}
EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats);
@ -1059,7 +1059,7 @@ int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
* Look for matching configuration - set the active configuration
* context if found.
*/
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
raw_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)) &&
@ -1069,7 +1069,7 @@ int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
break;
}
}
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
/*
* If found, attempt to enable
@ -1090,12 +1090,12 @@ int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
*
* Set enabled if OK, err if not.
*/
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
if (csdev->active_cscfg_ctxt)
config_csdev_active->enabled = true;
else
err = -EBUSY;
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
}
}
return err;
@ -1124,7 +1124,7 @@ void cscfg_csdev_disable_active_config(struct coresight_device *csdev)
* If it was not enabled, we have no work to do, otherwise mark as disabled.
* Clear the active config pointer.
*/
spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags);
config_csdev = (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt;
if (config_csdev) {
if (!config_csdev->enabled)
@ -1133,7 +1133,7 @@ void cscfg_csdev_disable_active_config(struct coresight_device *csdev)
config_csdev->enabled = false;
}
csdev->active_cscfg_ctxt = NULL;
spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags);
/* true if there was an enabled active config */
if (config_csdev)

2
include/linux/coresight.h
View File

@ -302,7 +302,7 @@ struct coresight_device {
/* system configuration and feature lists */
struct list_head feature_csdev_list;
struct list_head config_csdev_list;
spinlock_t cscfg_csdev_lock;
raw_spinlock_t cscfg_csdev_lock;
void *active_cscfg_ctxt;
};