Re: [PATCH v5 10/23] ArmPkg: Add helper to read the CCSIDR2 register

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

On Mon, Jan 04, 2021 at 15:58:17 -0700, Rebecca Cran wrote:
> Add helper function to read the CCSIDR2 register.
> This is used when CCIDX is supported in AARCH32 mode.
> 
> Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>

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

> ---
>  ArmPkg/Library/ArmLib/ArmLibPrivate.h         | 11 +++++++++++
>  ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S   | 10 ++++++++++
>  ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm | 10 ++++++++++
>  3 files changed, 31 insertions(+)
> 
> diff --git a/ArmPkg/Library/ArmLib/ArmLibPrivate.h b/ArmPkg/Library/ArmLib/ArmLibPrivate.h
> index 5d0224080f3f..e0ec065f1f4a 100644
> --- a/ArmPkg/Library/ArmLib/ArmLibPrivate.h
> +++ b/ArmPkg/Library/ArmLib/ArmLibPrivate.h
> @@ -170,6 +170,17 @@ ReadCCSIDR (
>    IN UINT32 CSSELR
>    );
>  
> +/** Reads the CCSIDR2 for the specified cache.
> +
> +  @param CSSELR The CSSELR cache selection register value
> +
> +  @return The contents of the CCSIDR2 register for the specified cache.
> +**/
> +UINT32
> +ReadCCSIDR2 (
> +  IN UINT32 CSSELR
> +  );
> +
>  UINT32
>  ReadCLIDR (
>    VOID
> diff --git a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S
> index af61dbee5261..8f75f5051083 100644
> --- a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S
> +++ b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.S
> @@ -74,6 +74,16 @@ ASM_FUNC(ReadCCSIDR)
>    mrc p15,1,r0,c0,c0,0   @ Read current CP15 Cache Size ID Register (CCSIDR)
>    bx  lr
>  
> +// UINT32
> +// ReadCCSIDR2 (
> +//   IN UINT32 CSSELR
> +//   )
> +ASM_FUNC(ReadCCSIDR2)
> +  mcr p15,2,r0,c0,c0,0   @ Write Cache Size Selection Register (CSSELR)
> +  isb
> +  mrc p15,1,r0,c0,c2,0   @ Read current CP15 Cache Size ID Register (CCSIDR2)
> +  bx  lr
> +
>  // UINT32
>  // ReadCLIDR (
>  //   IN UINT32 CSSELR
> diff --git a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm
> index 81f3cb79994c..2fa7a046c0c6 100644
> --- a/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm
> +++ b/ArmPkg/Library/ArmLib/Arm/ArmLibSupportV7.asm
> @@ -78,6 +78,16 @@
>    mrc p15,1,r0,c0,c0,0 ; Read current CP15 Cache Size ID Register (CCSIDR)
>    bx  lr
>  
> +// UINT32
> +// ReadCCSIDR2 (
> +//   IN UINT32 CSSELR
> +//   )
> + RVCT_ASM_EXPORT ReadCCSIDR2
> +  mcr p15,2,r0,c0,c0,0 ; Write Cache Size Selection Register (CSSELR)
> +  isb
> +  mrc p15,1,r0,c0,c2,0 ; Read current CP15 Cache Size ID Register (CCSIDR2)
> +  bx  lr
> +
>  // UINT32
>  // ReadCLIDR (
>  //   IN UINT32 CSSELR
> -- 
> 2.26.2
>