Install the callbacks via the state machine. CPU_UP_CANCELED_FROZEN() is not preserved: It is only here to free memory in an error case because it is assumed if the CPU does show up on resume it won't be seen ever again. As per Borislav: |IOW, you don't need mc_cpu_dead().
Cc: Borislav Petkov <[email protected]> Signed-off-by: Sebastian Andrzej Siewior <[email protected]> --- v1…v2: removal of mc_cpu_dead() arch/x86/kernel/cpu/microcode/core.c | 54 +++++++++++------------------------ 1 file changed, 18 insertions(+), 36 deletions(-) --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -558,55 +558,36 @@ 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; + if (sysfs_create_group(&dev->kobj, &mc_attr_group)) + pr_err("Failed to create group for CPU%d\n", cpu); + return 0; +} +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); /* - * 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; + return 0; } -static struct notifier_block mc_cpu_notifier = { - .notifier_call = mc_cpu_callback, -}; - static struct attribute *cpu_root_microcode_attrs[] = { &dev_attr_reload.attr, NULL @@ -665,7 +646,8 @@ 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); pr_info("Microcode Update Driver: v" MICROCODE_VERSION " <[email protected]>, Peter Oruba\n");
