lib: Add hfence instruction encoding

Currently, the toolchains do not have support for hfence instruction.
Hence, the instruction are hardcode until we have toolchain support.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

include/sbi/sbi_hfence.h

@@ -0,0 +1,36 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2019 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ *   Anup Patel <anup.patel@wdc.com>
+ */
+
+#ifndef __SBI_FENCE_H__
+#define __SBI_FENCE_H__
+/** Invalidate Stage2 TLBs for given VMID and guest physical address */
+void __sbi_hfence_gvma_vmid_gpa(unsigned long vmid, unsigned long gpa);
+
+/** Invalidate Stage2 TLBs for given VMID */
+void __sbi_hfence_gvma_vmid(unsigned long vmid);
+
+/** Invalidate Stage2 TLBs for given guest physical address */
+void __sbi_hfence_gvma_gpa(unsigned long gpa);
+
+/** Invalidate all possible Stage2 TLBs */
+void __sbi_hfence_gvma_all(void);
+
+/** Invalidate unified TLB entries for given asid and guest virtual address */
+void __sbi_hfence_vvma_asid_va(unsigned long asid, unsigned long va);
+
+/** Invalidate unified TLB entries for given ASID for a guest*/
+void __sbi_hfence_vvma_asid(unsigned long asid);
+
+/** Invalidate unified TLB entries for a given guest virtual address */
+void __sbi_hfence_vvma_va(unsigned long va);
+
+/** Invalidate all possible Stage2 TLBs */
+void __sbi_hfence_vvma_all(void);
+#endif