Install the callbacks via the state machine. There is little hackery with
mc_cpu_dead() which should only be called if CPU_UP failed durin resume.
This change may not fully represent the current behaviour. The current code
also behaves different if the CPU does not come up in the _cpu_up() state vs
one of the CPU_ONLINE notifier returned an error. Not sure what kind of a
problem is solved here.
Cc: Borislav Petkov <b...@alien8.de>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
arch/x86/kernel/cpu/microcode/core.c | 71 +++++++++++++++---------------------
include/linux/cpuhotplug.h | 1 +
2 files changed, 30 insertions(+), 42 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/core.c
b/arch/x86/kernel/cpu/microcode/core.c
index df04b2d033f6..4fc67b51e22e 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -558,54 +558,38 @@ static struct syscore_ops mc_syscore_ops = {
.resume = mc_bp_resume,
};
-static int
-mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
+static int mc_cpu_online(unsigned int cpu)
{
- unsigned int cpu = (unsigned long)hcpu;
struct device *dev;
dev = get_cpu_device(cpu);
+ microcode_update_cpu(cpu);
+ pr_debug("CPU%d added\n", cpu);
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_ONLINE:
- microcode_update_cpu(cpu);
- pr_debug("CPU%d added\n", cpu);
- /*
- * "break" is missing on purpose here because we want to fall
- * through in order to create the sysfs group.
- */
-
- case CPU_DOWN_FAILED:
- if (sysfs_create_group(&dev->kobj, &mc_attr_group))
- pr_err("Failed to create group for CPU%d\n", cpu);
- break;
-
- case CPU_DOWN_PREPARE:
- /* Suspend is in progress, only remove the interface */
- sysfs_remove_group(&dev->kobj, &mc_attr_group);
- pr_debug("CPU%d removed\n", cpu);
- break;
-
- /*
- * case CPU_DEAD:
- *
- * When a CPU goes offline, don't free up or invalidate the copy of
- * the microcode in kernel memory, so that we can reuse it when the
- * CPU comes back online without unnecessarily requesting the userspace
- * for it again.
- */
- }
-
- /* The CPU refused to come up during a system resume */
- if (action == CPU_UP_CANCELED_FROZEN)
- microcode_fini_cpu(cpu);
-
- return NOTIFY_OK;
+ if (sysfs_create_group(&dev->kobj, &mc_attr_group))
+ pr_err("Failed to create group for CPU%d\n", cpu);
+ return 0;
}
-static struct notifier_block mc_cpu_notifier = {
- .notifier_call = mc_cpu_callback,
-};
+static int mc_cpu_down_prep(unsigned int cpu)
+{
+ struct device *dev;
+
+ dev = get_cpu_device(cpu);
+ /* Suspend is in progress, only remove the interface */
+ sysfs_remove_group(&dev->kobj, &mc_attr_group);
+ pr_debug("CPU%d removed\n", cpu);
+ return 0;
+}
+
+static int mc_cpu_dead(unsigned int cpu)
+{
+#ifdef CONFIG_SMP
+ if (cpuhp_tasks_frozen)
+ microcode_fini_cpu(cpu);
+#endif
+ return 0;
+}
static struct attribute *cpu_root_microcode_attrs[] = {
&dev_attr_reload.attr,
@@ -665,7 +649,10 @@ int __init microcode_init(void)
goto out_ucode_group;
register_syscore_ops(&mc_syscore_ops);
- register_hotcpu_notifier(&mc_cpu_notifier);
+ cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
+ mc_cpu_online, mc_cpu_down_prep);
+ cpuhp_setup_state_nocalls(CPUHP_X86_MICRCODE_PREPARE,
+ "x86/microcode:prepare", NULL, mc_cpu_dead);
pr_info("Microcode Update Driver: v" MICROCODE_VERSION
" <tig...@aivazian.fsnet.co.uk>, Peter Oruba\n");
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 8dec2a236af3..4ca7551b902f 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -38,6 +38,7 @@ enum cpuhp_state {
CPUHP_NOTIFY_PREPARE,
CPUHP_ARM_SHMOBILE_SCU_PREPARE,
CPUHP_SH_SH3X_PREPARE,
+ CPUHP_X86_MICRCODE_PREPARE,
CPUHP_TIMERS_DEAD,
CPUHP_BRINGUP_CPU,
CPUHP_AP_IDLE_DEAD,
--
2.9.3
