#endif
#ifdef CONFIG_MICROCODE_LATE_LOADING
-/*
+/**
+ * microcode_check() - Check if any CPU capabilities changed after an update.
+ * @prev_info: CPU capabilities stored before an update.
+ *
* The microcode loader calls this upon late microcode load to recheck features,
* only when microcode has been updated. Caller holds microcode_mutex and CPU
* hotplug lock.
+ *
+ * Return: None
*/
-void microcode_check(void)
+void microcode_check(struct cpuinfo_x86 *prev_info)
{
- struct cpuinfo_x86 info;
-
perf_check_microcode();
/* Reload CPUID max function as it might've changed. */
- info.cpuid_level = cpuid_eax(0);
+ prev_info->cpuid_level = cpuid_eax(0);
/*
* Copy all capability leafs to pick up the synthetic ones so that
* memcmp() below doesn't fail on that. The ones coming from CPUID will
* get overwritten in get_cpu_cap().
*/
- memcpy(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability));
+ memcpy(&prev_info->x86_capability, &boot_cpu_data.x86_capability,
+ sizeof(prev_info->x86_capability));
- get_cpu_cap(&info);
+ get_cpu_cap(prev_info);
- if (!memcmp(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability)))
+ if (!memcmp(&prev_info->x86_capability, &boot_cpu_data.x86_capability,
+ sizeof(prev_info->x86_capability)))
return;
pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
static int microcode_reload_late(void)
{
int old = boot_cpu_data.microcode, ret;
+ struct cpuinfo_x86 prev_info;
pr_err("Attempting late microcode loading - it is dangerous and taints the kernel.\n");
pr_err("You should switch to early loading, if possible.\n");
ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask);
if (ret == 0)
- microcode_check();
+ microcode_check(&prev_info);
pr_info("Reload completed, microcode revision: 0x%x -> 0x%x\n",
old, boot_cpu_data.microcode);