linux-kernel - [PATCH v2 18/45] arm_mpam: resctrl: Implement resctrl_arch_reset_all

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251219181147.3404071-19-ben.horgan@arm.com>
Date: Fri, 19 Dec 2025 18:11:20 +0000
From: Ben Horgan <ben.horgan@....com>
To: ben.horgan@....com
Cc: amitsinght@...vell.com,
	baisheng.gao@...soc.com,
	baolin.wang@...ux.alibaba.com,
	carl@...amperecomputing.com,
	dave.martin@....com,
	david@...nel.org,
	dfustini@...libre.com,
	fenghuay@...dia.com,
	gshan@...hat.com,
	james.morse@....com,
	jonathan.cameron@...wei.com,
	kobak@...dia.com,
	lcherian@...vell.com,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	peternewman@...gle.com,
	punit.agrawal@....qualcomm.com,
	quic_jiles@...cinc.com,
	reinette.chatre@...el.com,
	rohit.mathew@....com,
	scott@...amperecomputing.com,
	sdonthineni@...dia.com,
	tan.shaopeng@...itsu.com,
	xhao@...ux.alibaba.com,
	catalin.marinas@....com,
	will@...nel.org,
	corbet@....net,
	maz@...nel.org,
	oupton@...nel.org,
	joey.gouly@....com,
	suzuki.poulose@....com,
	kvmarm@...ts.linux.dev
Subject: [PATCH v2 18/45] 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.

Signed-off-by: James Morse <james.morse@....com>
Signed-off-by: Ben Horgan <ben.horgan@....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 303aacfcb9d6..4f5d908d02a9 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -2544,7 +2544,7 @@ 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;
 
@@ -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;
 
@@ -2580,7 +2580,7 @@ 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 554e4887ba81..b9a739abb101 100644
--- a/drivers/resctrl/mpam_internal.h
+++ b/drivers/resctrl/mpam_internal.h
@@ -389,6 +389,13 @@ 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 bc4f1c80eab5..d32e87002457 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -167,6 +167,19 @@ 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)
 {
@@ -353,6 +366,8 @@ 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)
-- 
2.43.0