1 files changed, 63 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseLib/RiscV64/RiscVInterrupt.S b/roms/edk2/MdePkg/Library/BaseLib/RiscV64/RiscVInterrupt.S
new file mode 100644
index 000000000..87b3468fc
--- /dev/null
+++ b/roms/edk2/MdePkg/Library/BaseLib/RiscV64/RiscVInterrupt.S
@@ -0,0 +1,63 @@
+//------------------------------------------------------------------------------
+//
+// RISC-V Supervisor Mode interrupt enable/disable
+//
+// Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+
+ASM_GLOBAL ASM_PFX(RiscVDisableSupervisorModeInterrupts)
+ASM_GLOBAL ASM_PFX(RiscVEnableSupervisorModeInterrupt)
+ASM_GLOBAL ASM_PFX(RiscVGetSupervisorModeInterrupts)
+
+#define  SSTATUS_SIE                 0x00000002
+#define  CSR_SSTATUS                 0x100
+  #define  SSTATUS_SPP_BIT_POSITION  8
+
+//
+// This routine disables supervisor mode interrupt
+//
+ASM_PFX(RiscVDisableSupervisorModeInterrupts):
+  add   sp, sp, -(__SIZEOF_POINTER__)
+  sd    a1, (sp)
+  li    a1, SSTATUS_SIE
+  csrc  CSR_SSTATUS, a1
+  ld    a1, (sp)
+  add   sp, sp, (__SIZEOF_POINTER__)
+  ret
+
+//
+// This routine enables supervisor mode interrupt
+//
+ASM_PFX(RiscVEnableSupervisorModeInterrupt):
+  add   sp, sp, -2*(__SIZEOF_POINTER__)
+  sd    a0, (0*__SIZEOF_POINTER__)(sp)
+  sd    a1, (1*__SIZEOF_POINTER__)(sp)
+
+  csrr  a0, CSR_SSTATUS
+  and   a0, a0, (1 << SSTATUS_SPP_BIT_POSITION)
+  bnez  a0, InTrap      // We are in supervisor mode (SMode)
+                        // trap handler.
+                        // Skip enabling SIE becasue SIE
+                        // is set to disabled by RISC-V hart
+                        // when the trap takes hart to SMode.
+
+  li    a1, SSTATUS_SIE
+  csrs  CSR_SSTATUS, a1
+InTrap:
+  ld    a0, (0*__SIZEOF_POINTER__)(sp)
+  ld    a1, (1*__SIZEOF_POINTER__)(sp)
+  add   sp, sp, 2*(__SIZEOF_POINTER__)
+  ret
+
+//
+// This routine returns supervisor mode interrupt
+// status.
+//
+ASM_PFX(RiscVGetSupervisorModeInterrupts):
+  csrr a0, CSR_SSTATUS
+  andi a0, a0, SSTATUS_SIE
+  ret
+