From a45445b6093d4ffd83bb42da677c29959576fa59 Mon Sep 17 00:00:00 2001 From: Shouye Liu Date: Thu, 17 Apr 2025 11:23:21 +0800 Subject: [PATCH] platform/x86/intel-uncore-freq: Fix missing uncore sysfs during CPU hotplug MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 8d6955ed76e8a47115f2ea1d9c263ee6f505d737 upstream. In certain situations, the sysfs for uncore may not be present when all CPUs in a package are offlined and then brought back online after boot. This issue can occur if there is an error in adding the sysfs entry due to a memory allocation failure. Retrying to bring the CPUs online will not resolve the issue, as the uncore_cpu_mask is already set for the package before the failure condition occurs. This issue does not occur if the failure happens during module initialization, as the module will fail to load in the event of any error. To address this, ensure that the uncore_cpu_mask is not set until the successful return of uncore_freq_add_entry(). Fixes: dbce412a7733 ("platform/x86/intel-uncore-freq: Split common and enumeration part") Signed-off-by: Shouye Liu Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250417032321.75580-1-shouyeliu@gmail.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen Signed-off-by: Greg Kroah-Hartman --- .../x86/intel/uncore-frequency/uncore-frequency.c | 13 +++++++++---- 1 file changed, 9 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 a3b25253b6fde..2c9c5cc7d854e 100644 --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency.c @@ -121,15 +121,13 @@ 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; @@ -138,7 +136,14 @@ 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) + return ret; + + /* Use this CPU on this die as a control CPU */ + cpumask_set_cpu(cpu, &uncore_cpu_mask); + + return 0; } static int uncore_event_cpu_offline(unsigned int cpu) -- 2.47.3