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arm_mpam: Don't loop forever if there is the maximum possible amount of PARTIDs

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On a theoretical platform with the maximum possible number of usable
PARTIDs, 0XFFFF, the loops iterating over PARTID in mpam_reset_ris() and
mpam_reprogram_ris() will never reach their termination condition leading
to a system hang when register the cpu hotplug handlers when MPAM is
enabling.

Fix these loops.

Fixes: f188a36ca2 ("arm_mpam: Reset MSC controls from cpuhp callbacks")
Fixes: 09b89d2a72 ("arm_mpam: Allow configuration to be applied and restored during cpu online")
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>
This commit is contained in:
Ben Horgan 2026-09-17 15:56:15 +01:00 committed by James Morse
parent 09ff5358c6
commit 1e105782a1
1 changed files with 3 additions and 4 deletions
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7
drivers/resctrl/mpam_devices.c
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@ -1760,7 +1760,7 @@ static int mpam_save_mbwu_state(void *arg)
*/
static int mpam_reset_ris(void *arg)
{
u16 partid, partid_max;
u16 partid_max;
struct mpam_config reset_cfg = {};
struct mpam_msc_ris *ris = arg;
@ -1770,7 +1770,7 @@ static int mpam_reset_ris(void *arg)
spin_lock(&partid_max_lock);
partid_max = mpam_partid_max;
spin_unlock(&partid_max_lock);
for (partid = 0; partid <= partid_max; partid++)
for (u32 partid = 0; partid <= partid_max; partid++)
mpam_reprogram_ris_partid(ris, partid, &reset_cfg);
return 0;
@ -1817,7 +1817,6 @@ static int __write_config(void *arg)
static void mpam_reprogram_msc(struct mpam_msc *msc)
{
u16 partid;
bool reset;
struct mpam_config *cfg;
struct mpam_msc_ris *ris;
@ -1841,7 +1840,7 @@ static void mpam_reprogram_msc(struct mpam_msc *msc)
arg.comp = ris->vmsc->comp;
arg.ris = ris;
reset = true;
for (partid = 0; partid <= mpam_partid_max; partid++) {
for (u32 partid = 0; partid <= mpam_partid_max; partid++) {
cfg = &ris->vmsc->comp->cfg[partid];
if (!bitmap_empty(cfg->features, MPAM_FEATURE_LAST))
reset = false;