1 files changed, 133 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/BaseRiscV64CpuExceptionHandlerLib/CpuExceptionHandlerLib.c b/UefiCpuPkg/Library/BaseRiscV64CpuExceptionHandlerLib/CpuExceptionHandlerLib.c
new file mode 100644
index 0000000000..f1ee7d236a
--- /dev/null
+++ b/UefiCpuPkg/Library/BaseRiscV64CpuExceptionHandlerLib/CpuExceptionHandlerLib.c
@@ -0,0 +1,133 @@
+/** @file
+  RISC-V Exception Handler library implementation.
+
+  Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiPei.h>
+#include <Library/CpuExceptionHandlerLib.h>
+#include <Library/DebugLib.h>
+#include <Library/BaseLib.h>
+#include <Register/RiscV64/RiscVEncoding.h>
+
+#include "CpuExceptionHandlerLib.h"
+
+STATIC EFI_CPU_INTERRUPT_HANDLER  mInterruptHandlers[2];
+
+/**
+  Initializes all CPU exceptions entries and provides the default exception handlers.
+
+  Caller should try to get an array of interrupt and/or exception vectors that are in use and need to
+  persist by EFI_VECTOR_HANDOFF_INFO defined in PI 1.3 specification.
+  If caller cannot get reserved vector list or it does not exists, set VectorInfo to NULL.
+  If VectorInfo is not NULL, the exception vectors will be initialized per vector attribute accordingly.
+
+  @param[in]  VectorInfo    Pointer to reserved vector list.
+
+  @retval EFI_SUCCESS           CPU Exception Entries have been successfully initialized
+                                with default exception handlers.
+  @retval EFI_INVALID_PARAMETER VectorInfo includes the invalid content if VectorInfo is not NULL.
+  @retval EFI_UNSUPPORTED       This function is not supported.
+
+**/
+EFI_STATUS
+EFIAPI
+InitializeCpuExceptionHandlers (
+  IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL
+  )
+{
+  RiscVSetSupervisorStvec ((UINT64)SupervisorModeTrap);
+  return EFI_SUCCESS;
+}
+
+/**
+  Registers a function to be called from the processor interrupt handler.
+
+  This function registers and enables the handler specified by InterruptHandler for a processor
+  interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
+  handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
+  The installed handler is called once for each processor interrupt or exception.
+  NOTE: This function should be invoked after InitializeCpuExceptionHandlers() or
+  InitializeCpuInterruptHandlers() invoked, otherwise EFI_UNSUPPORTED returned.
+
+  @param[in]  InterruptType     Defines which interrupt or exception to hook.
+  @param[in]  InterruptHandler  A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
+                                when a processor interrupt occurs. If this parameter is NULL, then the handler
+                                will be uninstalled.
+
+  @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
+  @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
+                                previously installed.
+  @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
+                                previously installed.
+  @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported,
+                                or this function is not supported.
+**/
+EFI_STATUS
+EFIAPI
+RegisterCpuInterruptHandler (
+  IN EFI_EXCEPTION_TYPE         InterruptType,
+  IN EFI_CPU_INTERRUPT_HANDLER  InterruptHandler
+  )
+{
+  DEBUG ((DEBUG_INFO, "%a: Type:%x Handler: %x\n", __FUNCTION__, InterruptType, InterruptHandler));
+  mInterruptHandlers[InterruptType] = InterruptHandler;
+  return EFI_SUCCESS;
+}
+
+/**
+  Setup separate stacks for certain exception handlers.
+  If the input Buffer and BufferSize are both NULL, use global variable if possible.
+
+  @param[in]       Buffer        Point to buffer used to separate exception stack.
+  @param[in, out]  BufferSize    On input, it indicates the byte size of Buffer.
+                                 If the size is not enough, the return status will
+                                 be EFI_BUFFER_TOO_SMALL, and output BufferSize
+                                 will be the size it needs.
+
+  @retval EFI_SUCCESS             The stacks are assigned successfully.
+  @retval EFI_UNSUPPORTED         This function is not supported.
+  @retval EFI_BUFFER_TOO_SMALL    This BufferSize is too small.
+**/
+EFI_STATUS
+EFIAPI
+InitializeSeparateExceptionStacks (
+  IN     VOID   *Buffer,
+  IN OUT UINTN  *BufferSize
+  )
+{
+  return EFI_SUCCESS;
+}
+
+/**
+  Supervisor mode trap handler.
+
+  @param[in]  SmodeTrapReg     Registers before trap occurred.
+
+**/
+VOID
+RiscVSupervisorModeTrapHandler (
+  SMODE_TRAP_REGISTERS  *SmodeTrapReg
+  )
+{
+  UINTN               SCause;
+  EFI_SYSTEM_CONTEXT  RiscVSystemContext;
+
+  RiscVSystemContext.SystemContextRiscV64 = (EFI_SYSTEM_CONTEXT_RISCV64 *)SmodeTrapReg;
+  //
+  // Check scasue register.
+  //
+  SCause = (UINTN)RiscVGetSupervisorTrapCause ();
+  if ((SCause & (1UL << (sizeof (UINTN) * 8- 1))) != 0) {
+    //
+    // This is interrupt event.
+    //
+    SCause &= ~(1UL << (sizeof (UINTN) * 8- 1));
+    if ((SCause == IRQ_S_TIMER) && (mInterruptHandlers[EXCEPT_RISCV_TIMER_INT] != NULL)) {
+      mInterruptHandlers[EXCEPT_RISCV_TIMER_INT](EXCEPT_RISCV_TIMER_INT, RiscVSystemContext);
+    }
+  }
+}