Re: [edk2-devel] [PATCH v3 6/6] UefiCpuPkg/MpInitLib: return early in GetBspNumber()

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

On 2/22/24 17:01, Gerd Hoffmann wrote:
> After finding the BSP Number return the result instead of
> continuing to loop over the remaining processors.
> 
> Suggested-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  UefiCpuPkg/Library/MpInitLib/MpLib.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> index 4b6d6d02b027..2051554207dc 100644
> --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
> +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
> @@ -1903,15 +1903,13 @@ GetBspNumber (
>    )
>  {
>    UINT32             ApicId;
> -  UINT32             BspNumber;
>    UINT32             Index;
>    CONST MP_HAND_OFF  *MpHandOff;
>  
>    //
>    // Get the processor number for the BSP
>    //
> -  BspNumber = MAX_UINT32;
> -  ApicId    = GetInitialApicId ();
> +  ApicId = GetInitialApicId ();
>  
>    for (MpHandOff = FirstMpHandOff;
>         MpHandOff != NULL;
> @@ -1919,14 +1917,13 @@ GetBspNumber (
>    {
>      for (Index = 0; Index < MpHandOff->CpuCount; Index++) {
>        if (MpHandOff->Info[Index].ApicId == ApicId) {
> -        BspNumber = MpHandOff->ProcessorIndex + Index;
> +        return MpHandOff->ProcessorIndex + Index;
>        }
>      }
>    }
>  
> -  ASSERT (BspNumber != MAX_UINT32);
> -
> -  return BspNumber;
> +  ASSERT (FALSE);
> +  return 0;
>  }
>  
>  /**

There's a somewhat sneaky change in here: if we fail to find the BSP,
then (beyond tripping an assert like before) we now return 0, rather
than MAX_UINT32.

However, that's arguably more sensible, even.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Laszlo



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