1 files changed, 73 insertions, 0 deletions
diff --git a/kernel/up.c b/kernel/up.c
new file mode 100644
index 0000000000..a38b8b0952
--- /dev/null
+++ b/kernel/up.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Uniprocessor-only support functions.  The counterpart to kernel/smp.c
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/smp.h>
+#include <linux/hypervisor.h>
+
+int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
+				int wait)
+{
+	unsigned long flags;
+
+	if (cpu != 0)
+		return -ENXIO;
+
+	local_irq_save(flags);
+	func(info);
+	local_irq_restore(flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(smp_call_function_single);
+
+int smp_call_function_single_async(int cpu, struct __call_single_data *csd)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	csd->func(csd->info);
+	local_irq_restore(flags);
+	return 0;
+}
+EXPORT_SYMBOL(smp_call_function_single_async);
+
+/*
+ * Preemption is disabled here to make sure the cond_func is called under the
+ * same conditions in UP and SMP.
+ */
+void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
+			   void *info, bool wait, const struct cpumask *mask)
+{
+	unsigned long flags;
+
+	preempt_disable();
+	if ((!cond_func || cond_func(0, info)) && cpumask_test_cpu(0, mask)) {
+		local_irq_save(flags);
+		func(info);
+		local_irq_restore(flags);
+	}
+	preempt_enable();
+}
+EXPORT_SYMBOL(on_each_cpu_cond_mask);
+
+int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
+{
+	int ret;
+
+	if (cpu != 0)
+		return -ENXIO;
+
+	if (phys)
+		hypervisor_pin_vcpu(0);
+	ret = func(par);
+	if (phys)
+		hypervisor_pin_vcpu(-1);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(smp_call_on_cpu);