[edk2-devel] [PATCH] UefiCpuPkg: code refine

[Zhou Jianfeng <jianfeng.zhou@intel.com>]

Changes:
1) add volatile to 64bit variable to avoid being tore by compiler.
2) add OUT for parameter that might be changed.

Signed-off-by: Zhou Jianfeng <jianfeng.zhou@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
---
 .../Library/CpuPageTableLib/CpuPageTableMap.c | 38 +++++++++----------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
index ae4caf8dfe..d96ea5984c 100644
--- a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
+++ b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
@@ -20,10 +20,10 @@
 **/
 VOID
 PageTableLibSetPte4K (
-  IN IA32_PTE_4K         *Pte4K,
-  IN UINT64              Offset,
-  IN IA32_MAP_ATTRIBUTE  *Attribute,
-  IN IA32_MAP_ATTRIBUTE  *Mask
+  IN OUT IA32_PTE_4K         *Pte4K,
+  IN UINT64                  Offset,
+  IN IA32_MAP_ATTRIBUTE      *Attribute,
+  IN IA32_MAP_ATTRIBUTE      *Mask
   )
 {
   IA32_PTE_4K  LocalPte4K;
@@ -78,7 +78,7 @@ PageTableLibSetPte4K (
   }

   if (Pte4K->Uint64 != LocalPte4K.Uint64) {
-    Pte4K->Uint64 = LocalPte4K.Uint64;
+    *(volatile UINT64 *)&(Pte4K->Uint64) = LocalPte4K.Uint64;
   }
 }

@@ -94,10 +94,10 @@ PageTableLibSetPte4K (
 **/
 VOID
 PageTableLibSetPleB (
-  IN IA32_PAGE_LEAF_ENTRY_BIG_PAGESIZE  *PleB,
-  IN UINT64                             Offset,
-  IN IA32_MAP_ATTRIBUTE                 *Attribute,
-  IN IA32_MAP_ATTRIBUTE                 *Mask
+  IN OUT IA32_PAGE_LEAF_ENTRY_BIG_PAGESIZE  *PleB,
+  IN UINT64                                 Offset,
+  IN IA32_MAP_ATTRIBUTE                     *Attribute,
+  IN IA32_MAP_ATTRIBUTE                     *Mask
   )
 {
   IA32_PAGE_LEAF_ENTRY_BIG_PAGESIZE  LocalPleB;
@@ -154,7 +154,7 @@ PageTableLibSetPleB (
   }

   if (PleB->Uint64 != LocalPleB.Uint64) {
-    PleB->Uint64 = LocalPleB.Uint64;
+    *(volatile UINT64 *)&(PleB->Uint64) = LocalPleB.Uint64;
   }
 }

@@ -171,11 +171,11 @@ PageTableLibSetPleB (
 **/
 VOID
 PageTableLibSetPle (
-  IN UINTN               Level,
-  IN IA32_PAGING_ENTRY   *Ple,
-  IN UINT64              Offset,
-  IN IA32_MAP_ATTRIBUTE  *Attribute,
-  IN IA32_MAP_ATTRIBUTE  *Mask
+  IN UINTN                   Level,
+  IN OUT IA32_PAGING_ENTRY   *Ple,
+  IN UINT64                  Offset,
+  IN IA32_MAP_ATTRIBUTE      *Attribute,
+  IN IA32_MAP_ATTRIBUTE      *Mask
   )
 {
   if (Level == 1) {
@@ -195,9 +195,9 @@ PageTableLibSetPle (
 **/
 VOID
 PageTableLibSetPnle (
-  IN IA32_PAGE_NON_LEAF_ENTRY  *Pnle,
-  IN IA32_MAP_ATTRIBUTE        *Attribute,
-  IN IA32_MAP_ATTRIBUTE        *Mask
+  IN OUT IA32_PAGE_NON_LEAF_ENTRY  *Pnle,
+  IN IA32_MAP_ATTRIBUTE            *Attribute,
+  IN IA32_MAP_ATTRIBUTE            *Mask
   )
 {
   IA32_PAGE_NON_LEAF_ENTRY  LocalPnle;
@@ -231,7 +231,7 @@ PageTableLibSetPnle (
   LocalPnle.Bits.WriteThrough  = 0;
   LocalPnle.Bits.CacheDisabled = 0;
   if (Pnle->Uint64 != LocalPnle.Uint64) {
-    Pnle->Uint64 = LocalPnle.Uint64;
+    *(volatile UINT64 *)&(Pnle->Uint64) = LocalPnle.Uint64;
   }
 }

--
2.31.1.windows.1



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