Re: [PATCH v5 05/23] ArmPkg: Add helper function to read the Memory Model Feature Register 4

["Leif Lindholm" <leif@nuviainc.com>]

On Mon, Jan 04, 2021 at 15:58:12 -0700, Rebecca Cran wrote:
> In AARCH32, CCIDX support is indicated in the MMFR4 register - unlike
> under AARCH64 where it's in MMFR2. Add a helper function to read it.
> 
> Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
> Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

Reviewed-by: Leif Lindholm <leif@nuviainc.com>

However, and I say this as someone who usually tells people to split
their patches up: this one could be squashed with the preceding two.

> ---
>  ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h          | 8 ++++++--
>  ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S   | 4 ++++
>  ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm | 4 ++++
>  3 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h b/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h
> index bb7bda0a3aeb..dcf6723b803b 100644
> --- a/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h
> +++ b/ArmPkg/Library/ArmLib/Arm/ArmV7Lib.h
> @@ -48,9 +48,13 @@ ArmCleanInvalidateDataCacheEntryBySetWay (
>    IN  UINTN   SetWayFormat
>    );
>  
> -UINTN
> +/** Reads the ID_MMFR4 register.
> +
> +   @return The contents of the ID_MMFR4 register.
> +**/
> +UINT32
>  EFIAPI
> -ArmReadIdPfr0 (
> +ArmReadIdMmfr4 (
>    VOID
>    );
>  
> diff --git a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S
> index 01c91b10fcb7..a60a2f634132 100644
> --- a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S
> +++ b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S
> @@ -60,6 +60,10 @@ ASM_FUNC(ArmDisableInterrupts)
>    isb
>    bx      LR
>  
> +ASM_FUNC(ArmReadIdMmfr4)
> +  mrc    p15,0,r0,c0,c2,6     @ Read ID_MMFR4 Register
> +  bx     lr
> +
>  // UINT32
>  // ReadCCSIDR (
>  //   IN UINT32 CSSELR
> diff --git a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm
> index 26ffa331b929..1679b09b797a 100644
> --- a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm
> +++ b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm
> @@ -64,6 +64,10 @@
>    isb
>    bx      LR
>  
> + RVCT_ASM_EXPORT ArmReadIdMmfr4
> +  mrc    p15,0,r0,c0,c2,6     ; Read ID_MMFR4 Register
> +  bx     LR
> +
>  // UINT32
>  // ReadCCSIDR (
>  //   IN UINT32 CSSELR
> -- 
> 2.26.2
>