From: James Morse <james.morse@arm.com> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/... --------------------------- cpuhp callbacks aren't the only time the MSC configuration may need to be reset. Resctrl has an API call to reset a class. If an MPAM error interrupt arrives it indicates the driver has misprogrammed an MSC. The safest thing to do is reset all the MSCs and disable MPAM. Add a helper to reset RIS via their class. Call this from mpam_disable(), which can be scheduled from the error interrupt handler. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- drivers/platform/mpam/mpam_devices.c | 34 ++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/platform/mpam/mpam_devices.c b/drivers/platform/mpam/mpam_devices.c index 9156591fc4b9..6091e87308ba 100644 --- a/drivers/platform/mpam/mpam_devices.c +++ b/drivers/platform/mpam/mpam_devices.c @@ -1198,6 +1198,40 @@ static void mpam_enable_once(void) READ_ONCE(mpam_partid_max) + 1, mpam_pmg_max + 1); } +static void mpam_reset_class(struct mpam_class *class) +{ + int idx; + struct mpam_msc_ris *ris; + struct mpam_component *comp; + + idx = srcu_read_lock(&mpam_srcu); + list_for_each_entry_rcu(comp, &class->components, class_list) { + list_for_each_entry_rcu(ris, &comp->ris, comp_list) { + mutex_lock(&ris->msc->lock); + mpam_touch_msc(ris->msc, mpam_reset_ris, ris); + mutex_unlock(&ris->msc->lock); + ris->in_reset_state = true; + } + } + srcu_read_unlock(&mpam_srcu, idx); +} + +/* + * Called in response to an error IRQ. + * All of MPAMs errors indicate a software bug, restore any modified + * controls to their reset values. + */ +void mpam_disable(void) +{ + int idx; + struct mpam_class *class; + + idx = srcu_read_lock(&mpam_srcu); + list_for_each_entry_rcu(class, &mpam_classes, classes_list) + mpam_reset_class(class); + srcu_read_unlock(&mpam_srcu, idx); +} + /* * Enable mpam once all devices have been probed. * Scheduled by mpam_discovery_cpu_online() once all devices have been created. -- 2.25.1