summaryrefslogtreecommitdiff
path: root/drivers/resctrl
diff options
context:
space:
mode:
authorBen Horgan <ben.horgan@arm.com>2026-09-17 15:56:09 +0100
committerJames Morse <james.morse@arm.com>2026-10-02 17:39:30 +0100
commit0045b87f65bbdd3b433747cce0d723ae94f77d38 (patch)
tree2c4d440fe08c6af2293ab8b736c876476b04d2e4 /drivers/resctrl
parentb010d258f30a512a9eafaba6c50a0943f8420ab2 (diff)
arm_mpam: Add missing mon_sel locking in MBWU save and restore
The mon_sel_lock is used to protect the mbwu_state, as well as h/w accesses that use MPAMCFG_MON_SEL. However, in mpam_restore/save_mbwu_state(), mbwu_state is accessed without holding the mon_sel_lock. Add the missing locking. Fixes: 41e8a14950e1 ("arm_mpam: Track bandwidth counter state for power management") Signed-off-by: Ben Horgan <ben.horgan@arm.com> Tested-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
Diffstat (limited to 'drivers/resctrl')
-rw-r--r--drivers/resctrl/mpam_devices.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index e349db525882..d39d210574a6 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -1652,17 +1652,26 @@ static int mpam_restore_mbwu_state(void *_ris)
u64 val;
struct mon_read mwbu_arg;
struct mpam_msc_ris *ris = _ris;
+ struct mpam_msc *msc = ris->vmsc->msc;
struct mpam_class *class = ris->vmsc->comp->class;
for (i = 0; i < ris->props.num_mbwu_mon; i++) {
- if (ris->mbwu_state[i].enabled) {
- mwbu_arg.ris = ris;
- mwbu_arg.ctx = &ris->mbwu_state[i].cfg;
- mwbu_arg.type = mpam_msmon_choose_counter(class);
- mwbu_arg.val = &val;
+ if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc)))
+ return -EIO;
- __ris_msmon_read(&mwbu_arg);
+ if (!ris->mbwu_state[i].enabled) {
+ mpam_mon_sel_unlock(msc);
+ continue;
}
+
+ mwbu_arg.ris = ris;
+ mwbu_arg.ctx = &ris->mbwu_state[i].cfg;
+ mwbu_arg.type = mpam_msmon_choose_counter(class);
+ mwbu_arg.val = &val;
+
+ mpam_mon_sel_unlock(msc);
+
+ __ris_msmon_read(&mwbu_arg);
}
return 0;
@@ -1680,12 +1689,12 @@ static int mpam_save_mbwu_state(void *arg)
struct mpam_msc *msc = ris->vmsc->msc;
for (i = 0; i < ris->props.num_mbwu_mon; i++) {
- mbwu_state = &ris->mbwu_state[i];
- cfg = &mbwu_state->cfg;
-
if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc)))
return -EIO;
+ mbwu_state = &ris->mbwu_state[i];
+ cfg = &mbwu_state->cfg;
+
mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) |
FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx);
mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel);