diff options
Diffstat (limited to 'MdePkg/Library/BaseSynchronizationLib/Ia32')
-rw-r--r-- | MdePkg/Library/BaseSynchronizationLib/Ia32/InternalGetSpinLockProperties.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseSynchronizationLib/Ia32/InternalGetSpinLockProperties.c b/MdePkg/Library/BaseSynchronizationLib/Ia32/InternalGetSpinLockProperties.c new file mode 100644 index 0000000000..49f05fb18a --- /dev/null +++ b/MdePkg/Library/BaseSynchronizationLib/Ia32/InternalGetSpinLockProperties.c @@ -0,0 +1,60 @@ +/** @file
+ Internal function to get spin lock alignment.
+
+ Copyright (c) 2016, 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.
+
+**/
+
+#include "BaseSynchronizationLibInternals.h"
+
+/**
+ Internal function to retrieve the architecture specific spin lock alignment
+ requirements for optimal spin lock performance.
+
+ @return The architecture specific spin lock alignment.
+
+**/
+UINTN
+InternalGetSpinLockProperties (
+ VOID
+ )
+{
+ UINT32 RegEax;
+ UINT32 RegEbx;
+ UINTN FamilyId;
+ UINTN ModelId;
+ UINTN CacheLineSize;
+
+ //
+ // Retrieve CPUID Version Information
+ //
+ AsmCpuid (0x01, &RegEax, &RegEbx, NULL, NULL);
+ //
+ // EBX: Bits 15 - 08: CLFLUSH line size (Value * 8 = cache line size)
+ //
+ CacheLineSize = ((RegEbx >> 8) & 0xff) * 8;
+ //
+ // Retrieve CPU Family and Model
+ //
+ FamilyId = (RegEax >> 8) & 0xf;
+ ModelId = (RegEax >> 4) & 0xf;
+ if (FamilyId == 0x0f) {
+ //
+ // In processors based on Intel NetBurst microarchitecture, use two cache lines
+ //
+ ModelId = ModelId | ((RegEax >> 12) & 0xf0);
+ if (ModelId <= 0x04 || ModelId == 0x06) {
+ CacheLineSize *= 2;
+ }
+ }
+
+ return CacheLineSize;
+}
+
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