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

["Laszlo Ersek" <lersek@redhat.com>]

On 2/8/24 03:19, Zhou Jianfeng wrote:
> 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(-)

Sorry, just a superficial review for now.

- the two changes should be split to separate patches.

- the subject line is totally useless. please state (summarize) what
happens in the patch in the subject.

Laszlo

> 
> 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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