MdePkg: Add IOCSR operation for LoongArch

Add IoCsrRead8, IoCsrRead16, IoCsrRead32, IoCsrRead64, IoCsrWrite8,
IoCsrWrite16, IoCsrWrite32, IoCsrWrite64 to operate the IOCSR registers
of LoongArch architecture.

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4584

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Signed-off-by: Chao Li <lichao@loongson.cn>
Acked-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

MdePkg/Library/BaseLib/LoongArch64/IoCsr.S

@@ -0,0 +1,120 @@
+#------------------------------------------------------------------------------
+#
+# LoongArch ASM IO CSR operation functions
+#
+# Copyright (c) 2024, Loongson Technology Corporation Limited. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#------------------------------------------------------------------------------
+
+ASM_GLOBAL ASM_PFX (IoCsrRead8)
+ASM_GLOBAL ASM_PFX (IoCsrRead16)
+ASM_GLOBAL ASM_PFX (IoCsrRead32)
+ASM_GLOBAL ASM_PFX (IoCsrRead64)
+
+ASM_GLOBAL ASM_PFX (IoCsrWrite8)
+ASM_GLOBAL ASM_PFX (IoCsrWrite16)
+ASM_GLOBAL ASM_PFX (IoCsrWrite32)
+ASM_GLOBAL ASM_PFX (IoCsrWrite64)
+
+#/**
+#  IO CSR read byte operation.
+#
+#  @param[in]  Select   IO CSR read instruction select values.
+#
+#  @return     The return value of iocsrrd.b instruction.
+#
+#**/
+ASM_PFX (IoCsrRead8):
+  iocsrrd.b   $a0, $a0
+  jirl        $zero, $ra, 0
+
+#/**
+#  IO CSR read half word operation.
+#
+#  @param[in]  Select   IO CSR read instruction select values.
+#
+#  @return     The return value of iocsrrd.h instruction.
+#
+#**/
+ASM_PFX (IoCsrRead16):
+  iocsrrd.h   $a0, $a0
+  jirl        $zero, $ra, 0
+
+#/**
+#  IO CSR read word operation.
+#
+#  @param[in]  Select   IO CSR read instruction select values.
+#
+#  @return     The return value of iocsrrd.w instruction.
+#
+#**/
+ASM_PFX (IoCsrRead32):
+  iocsrrd.w   $a0, $a0
+  jirl        $zero, $ra, 0
+
+#/**
+#  IO CSR read double word operation. Only for LoongArch64.
+#
+#  @param[in]  Select   IO CSR read instruction select values.
+#
+#  @return     The return value of iocsrrd.d instruction.
+#
+#**/
+ASM_PFX (IoCsrRead64):
+  iocsrrd.d   $a0, $a0
+  jirl        $zero, $ra, 0
+
+#/**
+#  IO CSR write byte operation.
+#
+#  @param[in]  Select   IO CSR write instruction select values.
+#  @param[in]  Value    The iocsrwr.b will write the value.
+#
+#  @return     VOID.
+#
+#**/
+ASM_PFX (IoCsrWrite8):
+  iocsrwr.b   $a1, $a0
+  jirl        $zero, $ra, 0
+
+#/**
+#  IO CSR write half word operation.
+#
+#  @param[in]  Select   IO CSR write instruction select values.
+#  @param[in]  Value    The iocsrwr.h will write the value.
+#
+#  @return     VOID.
+#
+#**/
+ASM_PFX (IoCsrWrite16):
+  iocsrwr.h   $a1, $a0
+  jirl        $zero, $ra, 0
+
+#/**
+#  IO CSR write word operation.
+#
+#  @param[in]  Select   IO CSR write instruction select values.
+#  @param[in]  Value    The iocsrwr.w will write the value.
+#
+#  @return     VOID.
+#
+#**/
+ASM_PFX (IoCsrWrite32):
+  iocsrwr.w   $a1, $a0
+  jirl        $zero, $ra, 0
+
+#/**
+#  IO CSR write double word operation. Only for LoongArch64.
+#
+#  @param[in]  Select   IO CSR write instruction select values.
+#  @param[in]  Value    The iocsrwr.d will write the value.
+#
+#  @return     VOID.
+#
+#**/
+ASM_PFX (IoCsrWrite64):
+  iocsrwr.d   $a1, $a0
+  jirl        $zero, $ra, 0
+  .end