Commit ff5df3c6 authored by James Morse's avatar James Morse Committed by Zeng Heng
Browse files

arm_mpam: Extend reset logic to allow devices to be reset any time 

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/snapshot/v6.7-rc2



---------------------------

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: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarZeng Heng <zengheng4@huawei.com>
parent 67ec6d69

drivers/platform/mpam/mpam_devices.c

+34 −0
Original line number Diff line number Diff line
@@ -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.