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Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
-rw-r--r--arch/x86/kernel/cpu/common.c45
1 files changed, 30 insertions, 15 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index f3cc7699e1e1..6a25e93f2a87 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2302,30 +2302,45 @@ void cpu_init_secondary(void)
#endif
#ifdef CONFIG_MICROCODE_LATE_LOADING
-/*
+/**
+ * store_cpu_caps() - Store a snapshot of CPU capabilities
+ * @curr_info: Pointer where to store it
+ *
+ * Returns: None
+ */
+void store_cpu_caps(struct cpuinfo_x86 *curr_info)
+{
+ /* Reload CPUID max function as it might've changed. */
+ curr_info->cpuid_level = cpuid_eax(0);
+
+ /* Copy all capability leafs and pick up the synthetic ones. */
+ memcpy(&curr_info->x86_capability, &boot_cpu_data.x86_capability,
+ sizeof(curr_info->x86_capability));
+
+ /* Get the hardware CPUID leafs */
+ get_cpu_cap(curr_info);
+}
+
+/**
+ * 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;
+ struct cpuinfo_x86 curr_info;
perf_check_microcode();
- /* Reload CPUID max function as it might've changed. */
- 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));
-
- get_cpu_cap(&info);
+ store_cpu_caps(&curr_info);
- if (!memcmp(&info.x86_capability, &boot_cpu_data.x86_capability, sizeof(info.x86_capability)))
+ if (!memcmp(&prev_info->x86_capability, &curr_info.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");