Message ID | 20241216115006.415861-2-yeoreum.yun@arm.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | coresight: change some driver' spinlock type to raw_spinlock_t | expand |
On Mon, 16 Dec 2024 at 11:50, Yeoreum Yun <yeoreum.yun@arm.com> wrote: > > 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. > > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> > --- > .../hwtracing/coresight/coresight-syscfg.c | 26 +++++++++---------- > include/linux/coresight.h | 2 +- > 2 files changed, 14 insertions(+), 14 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c > index 11138a9762b0..a70c1454b410 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 c13342594278..924b58c343b3 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -296,7 +296,7 @@ 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; > }; > > -- > LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7} > Reviewed-by: Mike Leach <mike.leach@linaro.org> -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index 11138a9762b0..a70c1454b410 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 c13342594278..924b58c343b3 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -296,7 +296,7 @@ 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; };
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. Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> --- .../hwtracing/coresight/coresight-syscfg.c | 26 +++++++++---------- include/linux/coresight.h | 2 +- 2 files changed, 14 insertions(+), 14 deletions(-)