1 files changed, 87 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h
new file mode 100644
index 000000000000..9362c94fe3aa
--- /dev/null
+++ b/arch/powerpc/include/asm/paravirt.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _ASM_POWERPC_PARAVIRT_H
+#define _ASM_POWERPC_PARAVIRT_H
+
+#include <linux/jump_label.h>
+#include <asm/smp.h>
+#ifdef CONFIG_PPC64
+#include <asm/paca.h>
+#include <asm/hvcall.h>
+#endif
+
+#ifdef CONFIG_PPC_SPLPAR
+DECLARE_STATIC_KEY_FALSE(shared_processor);
+
+static inline bool is_shared_processor(void)
+{
+	return static_branch_unlikely(&shared_processor);
+}
+
+/* If bit 0 is set, the cpu has been preempted */
+static inline u32 yield_count_of(int cpu)
+{
+	__be32 yield_count = READ_ONCE(lppaca_of(cpu).yield_count);
+	return be32_to_cpu(yield_count);
+}
+
+static inline void yield_to_preempted(int cpu, u32 yield_count)
+{
+	plpar_hcall_norets(H_CONFER, get_hard_smp_processor_id(cpu), yield_count);
+}
+
+static inline void prod_cpu(int cpu)
+{
+	plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
+}
+
+static inline void yield_to_any(void)
+{
+	plpar_hcall_norets(H_CONFER, -1, 0);
+}
+#else
+static inline bool is_shared_processor(void)
+{
+	return false;
+}
+
+static inline u32 yield_count_of(int cpu)
+{
+	return 0;
+}
+
+extern void ___bad_yield_to_preempted(void);
+static inline void yield_to_preempted(int cpu, u32 yield_count)
+{
+	___bad_yield_to_preempted(); /* This would be a bug */
+}
+
+extern void ___bad_yield_to_any(void);
+static inline void yield_to_any(void)
+{
+	___bad_yield_to_any(); /* This would be a bug */
+}
+
+extern void ___bad_prod_cpu(void);
+static inline void prod_cpu(int cpu)
+{
+	___bad_prod_cpu(); /* This would be a bug */
+}
+
+#endif
+
+#define vcpu_is_preempted vcpu_is_preempted
+static inline bool vcpu_is_preempted(int cpu)
+{
+	if (!is_shared_processor())
+		return false;
+	if (yield_count_of(cpu) & 1)
+		return true;
+	return false;
+}
+
+static inline bool pv_is_native_spin_unlock(void)
+{
+	return !is_shared_processor();
+}
+
+#endif /* _ASM_POWERPC_PARAVIRT_H */