[PATCH] platform/x86/intel-uncore-freq: fix inconsistent state on init failure

shouyeliu
2025-04-14T09:21:42Z

When uncore_event_cpu_online() fails to initialize a control CPU (e.g.,
due to memory allocation failure or uncore_freq_add_entry() errors),
the code leaves stale entries in uncore_cpu_mask after that online CPU
will not try to call uncore_freq_add_entry, resulting in no sys interface.

Signed-off-by: shouyeliu <shouyeliu@gmail.com>
---
.../x86/intel/uncore-frequency/uncore-frequency.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c
index 40bbf8e45fa4..1de0a4a9d6cd 100644
--- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c
+++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c
@@ -146,15 +146,13 @@ static int uncore_event_cpu_online(unsigned int cpu)
{
struct uncore_data *data;
int target;
+ int ret;

/* Check if there is an online cpu in the package for uncore MSR */
target = cpumask_any_and(&uncore_cpu_mask, topology_die_cpumask(cpu));
if (target < nr_cpu_ids)
return 0;

- /* Use this CPU on this die as a control CPU */
- cpumask_set_cpu(cpu, &uncore_cpu_mask);
-
data = uncore_get_instance(cpu);
if (!data)
return 0;
@@ -163,7 +161,13 @@ static int uncore_event_cpu_online(unsigned int cpu)
data->die_id = topology_die_id(cpu);
data->domain_id = UNCORE_DOMAIN_ID_INVALID;

- return uncore_freq_add_entry(data, cpu);
+ ret = uncore_freq_add_entry(data, cpu);
+ if (!ret) {
+ /* Use this CPU on this die as a control CPU */
+ cpumask_set_cpu(cpu, &uncore_cpu_mask);
+ }
+
+ return ret;
}

static int uncore_event_cpu_offline(unsigned int cpu)
--
2.19.1