linux-kernel - [PATCH v4 16/41] arm_mpam: resctrl: Implement resctrl_arch_reset_all

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Message-ID: <20260203214342.584712-17-ben.horgan@arm.com>
Date: Tue,  3 Feb 2026 21:43:17 +0000
From: Ben Horgan <ben.horgan@....com>
To: ben.horgan@....com
Cc: amitsinght@...vell.com,
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	Shaopeng Tan <tan.shaopeng@...fujitsu.com>
Subject: [PATCH v4 16/41] arm_mpam: resctrl: Implement resctrl_arch_reset_all_ctrls()

From: James Morse <james.morse@....com>

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.

Tested-by: Gavin Shan <gshan@...hat.com>
Tested-by: Shaopeng Tan <tan.shaopeng@...fujitsu.com>
Tested-by: Peter Newman <peternewman@...gle.com>
Cc: Zeng Heng <zengheng4@...wei.com>
Signed-off-by: James Morse <james.morse@....com>
Signed-off-by: Ben Horgan <ben.horgan@....com>
---
Changes since v2:
Don't expose unlocked reset

Changes since v3:
Don't use or expose mpam_reset_component_locked()
---
 drivers/resctrl/mpam_devices.c  |  2 +-
 drivers/resctrl/mpam_internal.h |  3 +++
 drivers/resctrl/mpam_resctrl.c  | 13 +++++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index b81d5c7f44ca..bf99c37a80a7 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -2568,7 +2568,7 @@ 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;
 
diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h
index a9d89d9e18a8..21ade1620147 100644
--- a/drivers/resctrl/mpam_internal.h
+++ b/drivers/resctrl/mpam_internal.h
@@ -389,6 +389,9 @@ 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 under cpus_read_lock() */
+void mpam_reset_class_locked(struct mpam_class *class);
+
 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 a59d1659fe12..7fc0b515cfa4 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -169,6 +169,19 @@ 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)
 {
-- 
2.43.0