Subject: Re: [RFC PATCH v2 4/7] powerpc/ppc-opcode: consolidate powerpc instructions from bpf_jit.h

From: "Naveen N. Rao" <[email-masked]>
Date: Tue, 28 Apr 2020 21:49:22 +0530

Balamuruhan S wrote:
> move macro definitions of powerpc instructions from bpf_jit.h to ppc-opcode.h
> and adopt the users of the macros accordingly. `PPC_MR()` is defined twice in
> bpf_jit.h, remove the duplicate one.
> 
> Signed-off-by: Balamuruhan S <[email-masked]>
> ---
>  arch/powerpc/include/asm/ppc-opcode.h | 139 +++++++++++++
>  arch/powerpc/net/bpf_jit.h            | 166 ++-------------
>  arch/powerpc/net/bpf_jit32.h          |  24 +--
>  arch/powerpc/net/bpf_jit64.h          |  12 +-
>  arch/powerpc/net/bpf_jit_comp.c       | 132 ++++++------
>  arch/powerpc/net/bpf_jit_comp64.c     | 278 +++++++++++++-------------
>  6 files changed, 378 insertions(+), 373 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
> index 2ae0afc5c2bb..6b9a891884be 100644
> --- a/arch/powerpc/include/asm/ppc-opcode.h
> +++ b/arch/powerpc/include/asm/ppc-opcode.h
> @@ -79,6 +79,16 @@
>  #define IMM_L(i)               ((uintptr_t)(i) & 0xffff)
>  #define IMM_DS(i)              ((uintptr_t)(i) & 0xfffc)
> 
> +/*
> + * 16-bit immediate helper macros: HA() is for use with sign-extending instrs
> + * (e.g. LD, ADDI).  If the bottom 16 bits is "-ve", add another bit into the
> + * top half to negate the effect (i.e. 0xffff + 1 = 0x(1)0000).
> + */
> +#define IMM_H(i)                ((uintptr_t)(i)>>16)
> +#define IMM_HA(i)               (((uintptr_t)(i)>>16) +                       \
> +					(((uintptr_t)(i) & 0x8000) >> 15))
> +

Not needed for this patch series, but at some point, we should move over 
to using the PPC_LO(), PPC_HI() and PPC_HA() macros that are defined 
later in this file.

- Naveen