[PATCH net-next] PPC: bpf_jit_comp: add SKF_AD_HATYPE instruction

[Alexei Starovoitov]

On Wed, Nov 5, 2014 at 10:02 PM, Denis Kirjanov <kda at linux-powerpc.org> wrote:
> Add BPF extension SKF_AD_HATYPE to ppc JIT to check
> the hw type of the interface
>
> JIT off:
> [   69.106783] test_bpf: #20 LD_HATYPE 48 48 PASS
> JIT on:
> [   64.721757] test_bpf: #20 LD_HATYPE 7 6 PASS
>
> CC: Alexei Starovoitov<alexei.starovoitov at gmail.com>
> CC: Daniel Borkmann<dborkman at redhat.com>
> CC: Philippe Bergheaud<felix at linux.vnet.ibm.com>
> Signed-off-by: Denis Kirjanov <kda at linux-powerpc.org>
> ---
>  arch/powerpc/net/bpf_jit_comp.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
> index d110e28..8bf4fc2 100644
> --- a/arch/powerpc/net/bpf_jit_comp.c
> +++ b/arch/powerpc/net/bpf_jit_comp.c
> @@ -412,6 +412,22 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
>                         PPC_ANDI(r_A, r_A, PKT_TYPE_MAX);
>                         PPC_SRWI(r_A, r_A, 5);
>                         break;
> +               case BPF_ANC | SKF_AD_HATYPE:
> +                       BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2);
> +                       PPC_LD_OFFS(r_scratch1, r_skb, offsetof(struct sk_buff,
> +                                                               dev));
> +                       PPC_CMPDI(r_scratch1, 0);
> +                       if (ctx->pc_ret0 != -1) {
> +                               PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]);
> +                       } else {
> +                               /* Exit, returning 0; first pass hits here. */
> +                               PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12);

please use canonical formatting ctx->idx * 4 + 12

> +                               PPC_LI(r_ret, 0);
> +                               PPC_JMP(exit_addr);
> +                       }
> +                       PPC_LHZ_OFFS(r_A, r_scratch1,
> +                                    offsetof(struct net_device, type));

the whole thing looks like copy paste from 'case ifindex'.
Would be nice to handle them together to reduce
duplicated code, sine only last load is different.

Also in commit log please do _both_ runs with JIT on.
You should see a difference before/after applying this patch.