OvmfPkg/XenBusDxe: Add InterlockedCompareExchange16.

This patch is inspired by InterlockedCompareExchange32 from the
BaseSynchronizationLib.

The function will be used in the "OvmfPkg/XenBusDxe: Add Grant Table
functions" patch.

Change in V3:
- Implement both .S and .asm, to get rid of GCC specific asm.
- Implement 32bit part of the assembly

Change in V2:
- Add intel compilation code
  MSFT code is not compied over because I don't know how it works.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16263 6f19259b-4bc3-4df7-8a09-765794883524

7 files changed, 191 insertions, 0 deletions

diff --git a/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.S b/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.S
new file mode 100644
index 0000000..5306448
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.S
@@ -0,0 +1,15 @@
+# UINT16

+# EFIAPI

+# InternalSyncCompareExchange16 (

+#   IN      volatile UINT16           *Value,

+#   IN      UINT16                    CompareValue,

+#   IN      UINT16                    ExchangeValue

+#   );

+ASM_GLOBAL ASM_PFX(InternalSyncCompareExchange16)

+ASM_PFX(InternalSyncCompareExchange16):

+  mov 4(%esp), %ecx

+  mov 8(%esp), %eax

+  mov 12(%esp), %edx

+  lock

+  cmpxchgw %dx, (%ecx)

+  ret

diff --git a/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.asm b/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.asm
new file mode 100644
index 0000000..adcfbd0
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.asm
@@ -0,0 +1,45 @@
+;------------------------------------------------------------------------------

+;

+; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>

+; This program and the accompanying materials

+; are licensed and made available under the terms and conditions of the BSD License

+; which accompanies this distribution.  The full text of the license may be found at

+; http://opensource.org/licenses/bsd-license.php.

+;

+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,

+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

+;

+; Module Name:

+;

+;   InterlockedCompareExchange16.Asm

+;

+; Abstract:

+;

+;   InterlockedCompareExchange16 function

+;

+; Notes:

+;

+;------------------------------------------------------------------------------

+

+    .486

+    .model  flat,C

+    .code

+

+;------------------------------------------------------------------------------

+; UINT32

+; EFIAPI

+; InternalSyncCompareExchange16 (

+;   IN      UINT16                    *Value,

+;   IN      UINT16                    CompareValue,

+;   IN      UINT16                    ExchangeValue

+;   );

+;------------------------------------------------------------------------------

+InternalSyncCompareExchange16   PROC

+    mov     ecx, [esp + 4]

+    mov     eax, [esp + 8]

+    mov     edx, [esp + 12]

+    lock    cmpxchg [ecx], dx

+    ret

+InternalSyncCompareExchange16   ENDP

+

+    END

diff --git a/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c b/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c
new file mode 100644
index 0000000..2b0fadd
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c
@@ -0,0 +1,33 @@
+#include <Library/DebugLib.h>

+#include "InterlockedCompareExchange16.h"

+

+/**

+  Performs an atomic compare exchange operation on a 16-bit unsigned integer.

+

+  Performs an atomic compare exchange operation on the 16-bit unsigned integer

+  specified by Value.  If Value is equal to CompareValue, then Value is set to

+  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,

+  then Value is returned.  The compare exchange operation must be performed using

+  MP safe mechanisms.

+

+  If Value is NULL, then ASSERT().

+

+  @param  Value         A pointer to the 16-bit value for the compare exchange

+                        operation.

+  @param  CompareValue  16-bit value used in compare operation.

+  @param  ExchangeValue 16-bit value used in exchange operation.

+

+  @return The original *Value before exchange.

+

+**/

+UINT16

+EFIAPI

+InterlockedCompareExchange16 (

+  IN OUT  UINT16                    *Value,

+  IN      UINT16                    CompareValue,

+  IN      UINT16                    ExchangeValue

+  )

+{

+  ASSERT (Value != NULL);

+  return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue);

+}

diff --git a/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h b/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h
new file mode 100644
index 0000000..fd3f15b
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h
@@ -0,0 +1,38 @@
+/**

+  Assembly implementation of InterlockedCompareExchange16.

+

+  Look at the documentation of InterlockedCompareExchange16.

+**/

+UINT16

+EFIAPI

+InternalSyncCompareExchange16 (

+  IN      volatile UINT16           *Value,

+  IN      UINT16                    CompareValue,

+  IN      UINT16                    ExchangeValue

+  );

+

+/**

+  Performs an atomic compare exchange operation on a 16-bit unsigned integer.

+

+  Performs an atomic compare exchange operation on the 16-bit unsigned integer

+  specified by Value.  If Value is equal to CompareValue, then Value is set to

+  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,

+  then Value is returned.  The compare exchange operation must be performed using

+  MP safe mechanisms.

+

+  If Value is NULL, then ASSERT().

+

+  @param  Value         A pointer to the 16-bit value for the compare exchange

+                        operation.

+  @param  CompareValue  16-bit value used in compare operation.

+  @param  ExchangeValue 16-bit value used in exchange operation.

+

+  @return The original *Value before exchange.

+**/

+UINT16

+EFIAPI

+InterlockedCompareExchange16 (

+  IN OUT  UINT16                    *Value,

+  IN      UINT16                    CompareValue,

+  IN      UINT16                    ExchangeValue

+  );

diff --git a/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.S b/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.S
new file mode 100644
index 0000000..23e08f3
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.S
@@ -0,0 +1,13 @@
+# UINT16

+# EFIAPI

+# InternalSyncCompareExchange16 (

+#   IN      volatile UINT16           *Value,

+#   IN      UINT16                    CompareValue,

+#   IN      UINT16                    ExchangeValue

+#   );

+ASM_GLOBAL ASM_PFX(InternalSyncCompareExchange16)

+ASM_PFX(InternalSyncCompareExchange16):

+  mov %edx, %eax

+  lock

+  cmpxchgw %r8w, (%rcx)

+  ret

diff --git a/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.asm b/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.asm
new file mode 100644
index 0000000..b23e421
--- /dev/null
+++ b/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.asm
@@ -0,0 +1,41 @@
+;------------------------------------------------------------------------------

+;

+; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>

+; This program and the accompanying materials

+; are licensed and made available under the terms and conditions of the BSD License

+; which accompanies this distribution.  The full text of the license may be found at

+; http://opensource.org/licenses/bsd-license.php.

+;

+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,

+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

+;

+; Module Name:

+;

+;   InterlockedCompareExchange16.Asm

+;

+; Abstract:

+;

+;   InterlockedCompareExchange16 function

+;

+; Notes:

+;

+;------------------------------------------------------------------------------

+

+    .code

+

+;------------------------------------------------------------------------------

+; UINT16

+; EFIAPI

+; InterlockedCompareExchange16 (

+;   IN      UINT16                    *Value,

+;   IN      UINT16                    CompareValue,

+;   IN      UINT16                    ExchangeValue

+;   );

+;------------------------------------------------------------------------------

+InternalSyncCompareExchange16   PROC

+    mov     eax, edx

+    lock    cmpxchg [rcx], r8w

+    ret

+InternalSyncCompareExchange16   ENDP

+

+    END

diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.inf b/OvmfPkg/XenBusDxe/XenBusDxe.inf
index add8521..4e92a20 100644
--- a/OvmfPkg/XenBusDxe/XenBusDxe.inf
+++ b/OvmfPkg/XenBusDxe/XenBusDxe.inf
@@ -36,14 +36,20 @@
   ComponentName.h

   XenHypercall.c

   XenHypercall.h

+  InterlockedCompareExchange16.c

+  InterlockedCompareExchange16.h

 

 [Sources.IA32]

   Ia32/hypercall.S

   Ia32/hypercall.asm

+  Ia32/InterlockedCompareExchange16.S

+  Ia32/InterlockedCompareExchange16.asm

 

 [Sources.X64]

   X64/hypercall.S

   X64/hypercall.asm

+  X64/InterlockedCompareExchange16.S

+  X64/InterlockedCompareExchange16.asm

 

 [LibraryClasses]

   UefiDriverEntryPoint