MdePkg/BaseLib: RISC-V: Add few more helper functions

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4076

Few of the basic helper functions required for any
RISC-V CPU were added in edk2-platforms. To support
qemu virt, they need to be added in BaseLib.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Daniel Schaefer <git@danielschaefer.me>
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Abner Chang <abner.chang@amd.com>
Reviewed-by: Andrei Warkentin <andrei.warkentin@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>

MdePkg/Include/Library/BaseLib.h

@@ -151,6 +151,56 @@ typedef struct {
 
 #define BASE_LIBRARY_JUMP_BUFFER_ALIGNMENT  8
 
+VOID
+RiscVSetSupervisorScratch (
+  IN UINT64
+  );
+
+UINT64
+RiscVGetSupervisorScratch (
+  VOID
+  );
+
+VOID
+RiscVSetSupervisorStvec (
+  IN UINT64
+  );
+
+UINT64
+RiscVGetSupervisorStvec (
+  VOID
+  );
+
+UINT64
+RiscVGetSupervisorTrapCause (
+  VOID
+  );
+
+VOID
+RiscVSetSupervisorAddressTranslationRegister (
+  IN UINT64
+  );
+
+UINT64
+RiscVReadTimer (
+  VOID
+  );
+
+VOID
+RiscVEnableTimerInterrupt (
+  VOID
+  );
+
+VOID
+RiscVDisableTimerInterrupt (
+  VOID
+  );
+
+VOID
+RiscVClearPendingTimerInterrupt (
+  VOID
+  );
+
 #endif // defined (MDE_CPU_RISCV64)
 
 #if defined (MDE_CPU_LOONGARCH64)

MdePkg/Library/BaseLib/BaseLib.inf

@@ -401,6 +401,9 @@
   RiscV64/RiscVCpuPause.S           | GCC
   RiscV64/RiscVInterrupt.S          | GCC
   RiscV64/FlushCache.S              | GCC
+  RiscV64/CpuScratch.S              | GCC
+  RiscV64/ReadTimer.S               | GCC
+  RiscV64/RiscVMmu.S                | GCC
 
 [Sources.LOONGARCH64]
   Math64.c

MdePkg/Library/BaseLib/RiscV64/CpuScratch.S

@@ -0,0 +1,31 @@
+//------------------------------------------------------------------------------
+//
+// CPU scratch register related functions for RISC-V
+//
+// Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+
+#include <Register/RiscV64/RiscVImpl.h>
+
+.data
+.align 3
+.section .text
+
+//
+// Set Supervisor mode scratch.
+// @param a0 : Value set to Supervisor mode scratch
+//
+ASM_FUNC (RiscVSetSupervisorScratch)
+    csrw CSR_SSCRATCH, a0
+    ret
+
+//
+// Get Supervisor mode scratch.
+// @retval a0 : Value in Supervisor mode scratch
+//
+ASM_FUNC (RiscVGetSupervisorScratch)
+    csrr a0, CSR_SSCRATCH
+    ret

MdePkg/Library/BaseLib/RiscV64/ReadTimer.S

@@ -0,0 +1,23 @@
+//------------------------------------------------------------------------------
+//
+// Read CPU timer
+//
+// Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+
+#include <Register/RiscV64/RiscVImpl.h>
+
+.data
+.align 3
+.section .text
+
+//
+// Read TIME CSR.
+// @retval a0 : 64-bit timer.
+//
+ASM_FUNC (RiscVReadTimer)
+    csrr a0, CSR_TIME
+    ret

MdePkg/Library/BaseLib/RiscV64/RiscVInterrupt.S

@@ -8,13 +8,13 @@
 //
 //------------------------------------------------------------------------------
 
+#include <Register/RiscV64/RiscVImpl.h>
+
 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
+#define  SSTATUS_SPP_BIT_POSITION  8
 
 //
 // This routine disables supervisor mode interrupt
@@ -53,11 +53,56 @@ InTrap:
   ret
 
 //
+// Set Supervisor mode trap vector.
+// @param a0 : Value set to Supervisor mode trap vector
+//
+ASM_FUNC (RiscVSetSupervisorStvec)
+    csrrw a1, CSR_STVEC, a0
+    ret
+
+//
+// Get Supervisor mode trap vector.
+// @retval a0 : Value in Supervisor mode trap vector
+//
+ASM_FUNC (RiscVGetSupervisorStvec)
+    csrr a0, CSR_STVEC
+    ret
+
+//
+// Get Supervisor trap cause CSR.
+//
+ASM_FUNC (RiscVGetSupervisorTrapCause)
+    csrrs a0, CSR_SCAUSE, 0
+    ret
+//
 // This routine returns supervisor mode interrupt
 // status.
 //
-ASM_PFX(RiscVGetSupervisorModeInterrupts):
+ASM_FUNC (RiscVGetSupervisorModeInterrupts)
   csrr a0, CSR_SSTATUS
   andi a0, a0, SSTATUS_SIE
   ret
 
+//
+// This routine disables supervisor mode timer interrupt
+//
+ASM_FUNC (RiscVDisableTimerInterrupt)
+    li   a0, SIP_STIP
+    csrc CSR_SIE, a0
+    ret
+
+//
+// This routine enables supervisor mode timer interrupt
+//
+ASM_FUNC (RiscVEnableTimerInterrupt)
+    li    a0, SIP_STIP
+    csrs CSR_SIE, a0
+    ret
+
+//
+// This routine clears pending supervisor mode timer interrupt
+//
+ASM_FUNC (RiscVClearPendingTimerInterrupt)
+    li   a0, SIP_STIP
+    csrc CSR_SIP, a0
+    ret

MdePkg/Library/BaseLib/RiscV64/RiscVMmu.S

@@ -0,0 +1,23 @@
+//------------------------------------------------------------------------------
+//
+// CPU scratch register related functions for RISC-V
+//
+// Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+
+#include <Register/RiscV64/RiscVImpl.h>
+
+.data
+.align 3
+.section .text
+
+//
+// Set Supervisor Address Translation and
+// Protection Register.
+//
+ASM_FUNC (RiscVSetSupervisorAddressTranslationRegister)
+    csrw  CSR_SATP, a0
+    ret