1 files changed, 56 insertions, 4 deletions

diff --git a/kernel/up.c b/kernel/up.c
index c54c75e9faf7..df50828cc2f0 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Uniprocessor-only support functions.  The counterpart to kernel/smp.c
  */
@@ -6,16 +7,67 @@
 #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)
 {
-	WARN_ON(cpu != 0);
+	unsigned long flags;
 
-	local_irq_disable();
-	(func)(info);
-	local_irq_enable();
+	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, call_single_data_t *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);