From: Yeoreum Yun Date: Thu, 6 Mar 2025 12:11:02 +0000 (+0000) Subject: coresight: change coresight_device lock type to raw_spinlock_t X-Git-Tag: v6.15-rc1~78^2^2~11 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=26f060c106f630e34876c096c1c8997a9e68c371;p=thirdparty%2Fkernel%2Flinux.git coresight: change coresight_device lock type to raw_spinlock_t 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 Reviewed-by: Mike Leach Signed-off-by: Yeoreum Yun Signed-off-by: Suzuki K Poulose Link: https://lore.kernel.org/r/20250306121110.1647948-2-yeoreum.yun@arm.com --- diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index 11138a9762b01..a70c1454b4106 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -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) diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 89b781e70fe77..4541bfc1cc6bb 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -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; };