[PATCH v2 8/9] MdePkg/BaseSynchronizationLib: RISC-V cache related code.

["Abner Chang" <abner.chang@hpe.com>]

Support RISC-V cache related functions.

Signed-off-by: Abner Chang <abner.chang@hpe.com>
Co-authored-by: Gilbert Chen <gilbert.chen@hpe.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Gilbert Chen <gilbert.chen@hpe.com>
---
 .../BaseSynchronizationLib.inf                |  5 ++
 .../RiscV64/Synchronization.S                 | 78 +++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 MdePkg/Library/BaseSynchronizationLib/RiscV64/Synchronization.S

diff --git a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
index 446bc19b63..83d5b8ed7c 100755
--- a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
+++ b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
@@ -3,6 +3,7 @@
 #
 #  Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.<BR>
 #  Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+#  Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -78,6 +79,10 @@
   AArch64/Synchronization.S     | GCC
   AArch64/Synchronization.asm   | MSFT
 
+[Sources.RISCV64]
+  Synchronization.c
+  RiscV64/Synchronization.S
+
 [Packages]
   MdePkg/MdePkg.dec
 
diff --git a/MdePkg/Library/BaseSynchronizationLib/RiscV64/Synchronization.S b/MdePkg/Library/BaseSynchronizationLib/RiscV64/Synchronization.S
new file mode 100644
index 0000000000..bac80d6871
--- /dev/null
+++ b/MdePkg/Library/BaseSynchronizationLib/RiscV64/Synchronization.S
@@ -0,0 +1,78 @@
+//------------------------------------------------------------------------------
+//
+// RISC-V synchronization functions.
+//
+// Copyright (c) 2020, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//------------------------------------------------------------------------------
+#include <Base.h>
+
+.data
+
+.text
+.align 3
+
+.global ASM_PFX(InternalSyncCompareExchange32)
+.global ASM_PFX(InternalSyncCompareExchange64)
+.global ASM_PFX(InternalSyncIncrement)
+.global ASM_PFX(InternalSyncDecrement)
+
+//
+// ompare and xchange a 32-bit value.
+//
+// @param a0 : Pointer to 32-bit value.
+// @param a1 : Compare value.
+// @param a2 : Exchange value.
+//
+ASM_PFX (InternalSyncCompareExchange32):
+    lr.w  a3, (a0)        // Load the value from a0 and make
+                          // the reservation of address.
+    bne   a3, a1, exit
+    sc.w  a3, a2, (a0)    // Write the value back to the address.
+    mv    a3, a1
+exit:
+    mv    a0, a3
+    ret
+
+.global ASM_PFX(InternalSyncCompareExchange64)
+
+//
+// Compare and xchange a 64-bit value.
+//
+// @param a0 : Pointer to 64-bit value.
+// @param a1 : Compare value.
+// @param a2 : Exchange value.
+//
+ASM_PFX (SyncCompareExchange64):
+    lr.d  a3, (a0)       // Load the value from a0 and make
+                         // the reservation of address.
+    bne   a3, a1, exit
+    sc.d  a3, a2, (a0)   // Write the value back to the address.
+    mv    a3, a1
+exit2:
+    mv    a0, a3
+    ret
+
+//
+// Performs an atomic increment of an 32-bit unsigned integer.
+//
+// @param a0 : Pointer to 32-bit value.
+//
+ASM_PFX (InternalSyncIncrement):
+    li  a1, 1
+    amoadd.w  a2, a1, (a0)
+    mv  a0, a2
+    ret
+
+//
+// Performs an atomic decrement of an 32-bit unsigned integer.
+//
+// @param a0 : Pointer to 32-bit value.
+//
+ASM_PFX (InternalSyncDecrement):
+    li  a1, -1
+    amoadd.w  a2, a1, (a0)
+    mv  a0, a2
+    ret
-- 
2.25.0