[RFC PATCH 09/38] arm_mpam: resctrl: Implement resctrl_arch_reset_all_ctrls()

James Morse james.morse at arm.com
Fri Dec 5 13:58:32 PST 2025


We already have a helper for resetting an mpam class and component.
Hook it up to resctrl_arch_reset_all_ctrls() and the domain offline
path.

Signed-off-by: James Morse <james.morse at arm.com>
---
 drivers/resctrl/mpam_devices.c  |  6 +++---
 drivers/resctrl/mpam_internal.h |  7 +++++++
 drivers/resctrl/mpam_resctrl.c  | 15 +++++++++++++++
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index efaf7633bc35..fccebfd980d8 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -2543,7 +2543,7 @@ static void mpam_enable_once(void)
 	       mpam_partid_max + 1, mpam_pmg_max + 1);
 }
 
-static void mpam_reset_component_locked(struct mpam_component *comp)
+void mpam_reset_component_locked(struct mpam_component *comp)
 {
 	struct mpam_vmsc *vmsc;
 
@@ -2567,7 +2567,7 @@ static void mpam_reset_component_locked(struct mpam_component *comp)
 	}
 }
 
-static void mpam_reset_class_locked(struct mpam_class *class)
+void mpam_reset_class_locked(struct mpam_class *class)
 {
 	struct mpam_component *comp;
 
@@ -2579,7 +2579,7 @@ static void mpam_reset_class_locked(struct mpam_class *class)
 		mpam_reset_component_locked(comp);
 }
 
-static void mpam_reset_class(struct mpam_class *class)
+void mpam_reset_class(struct mpam_class *class)
 {
 	cpus_read_lock();
 	mpam_reset_class_locked(class);
diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h
index dfd3512ac924..8684bd35d4ab 100644
--- a/drivers/resctrl/mpam_internal.h
+++ b/drivers/resctrl/mpam_internal.h
@@ -392,6 +392,13 @@ extern u8 mpam_pmg_max;
 void mpam_enable(struct work_struct *work);
 void mpam_disable(struct work_struct *work);
 
+/* Reset all the RIS in a class, optionally while holding cpus_read_lock() */
+void mpam_reset_class_locked(struct mpam_class *class);
+void mpam_reset_class(struct mpam_class *class);
+
+/* Reset all the RIS in a component under cpus_read_lock() */
+void mpam_reset_component_locked(struct mpam_component *comp);
+
 int mpam_apply_config(struct mpam_component *comp, u16 partid,
 		      struct mpam_config *cfg);
 
diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index ceaf11af4fc1..a2deea1f4818 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -168,6 +168,19 @@ static int mpam_resctrl_pick_domain_id(int cpu, struct mpam_component *comp)
 	return comp->comp_id;
 }
 
+void resctrl_arch_reset_all_ctrls(struct rdt_resource *r)
+{
+	struct mpam_resctrl_res *res;
+
+	lockdep_assert_cpus_held();
+
+	if (!mpam_is_enabled())
+		return;
+
+	res = container_of(r, struct mpam_resctrl_res, resctrl_res);
+	mpam_reset_class_locked(res->class);
+}
+
 static void mpam_resctrl_domain_hdr_init(int cpu, struct mpam_component *comp,
 					 struct rdt_domain_hdr *hdr)
 {
@@ -339,6 +352,8 @@ void mpam_resctrl_offline_cpu(unsigned int cpu)
 
 		ctrl_dom_empty = true;
 		if (exposed_alloc_capable) {
+			mpam_reset_component_locked(dom->ctrl_comp);
+
 			ctrl_d = &dom->resctrl_ctrl_dom;
 			ctrl_dom_empty = mpam_resctrl_offline_domain_hdr(cpu, &ctrl_d->hdr);
 			if (ctrl_dom_empty)
-- 
2.39.5




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