diff --git a/MAINTAINERS b/MAINTAINERS
index a727d9959ecd..9c567a431d8d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11318,6 +11318,20 @@ F:	include/trace/
 F:	kernel/trace/
 F:	tools/testing/selftests/ftrace/
 
+TRACING MMIO ACCESSES (MMIOTRACE)
+M:	Steven Rostedt <rostedt@goodmis.org>
+M:	Ingo Molnar <mingo@kernel.org>
+R:	Karol Herbst <karolherbst@gmail.com>
+R:	Pekka Paalanen <ppaalanen@gmail.com>
+S:	Maintained
+L:	linux-kernel@vger.kernel.org
+L:	nouveau@lists.freedesktop.org
+F:	kernel/trace/trace_mmiotrace.c
+F:	include/linux/mmiotrace.h
+F:	arch/x86/mm/kmmio.c
+F:	arch/x86/mm/mmio-mod.c
+F:	arch/x86/mm/testmmiotrace.c
+
 TRIVIAL PATCHES
 M:	Jiri Kosina <trivial@kernel.org>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial.git
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 1f7fdb91a818..e4393bfc7f0d 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -336,7 +336,7 @@ static int intel_num_cpu_cores(struct cpuinfo_x86 *c)
 {
 	unsigned int eax, ebx, ecx, edx;
 
-	if (c->cpuid_level < 4)
+	if (!IS_ENABLED(CONFIG_SMP) || c->cpuid_level < 4)
 		return 1;
 
 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index a2065d3b3b39..0e4329ed91ef 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -332,6 +332,11 @@ static void __init smp_init_package_map(void)
 	 * primary cores.
 	 */
 	ncpus = boot_cpu_data.x86_max_cores;
+	if (!ncpus) {
+		pr_warn("x86_max_cores == zero !?!?");
+		ncpus = 1;
+	}
+
 	__max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus);
 
 	/*