Hi Ben, Vladimir,
*dusts off very thick PPC cobwebs* Sorry for the delay as I'm travelling, didn't get to this until now. On 02/09/2013, at 9:45 PM, Benjamin Herrenschmidt wrote: > On Mon, 2013-09-02 at 19:48 +0200, Vladimir Murzin wrote: >> Ping >> >> On Wed, Aug 28, 2013 at 02:49:52AM +0400, Vladimir Murzin wrote: >>> commit b6069a9570 (filter: add MOD operation) added generic >>> support for modulus operation in BPF. >>> > Sorry, nobody got a chance to review that yet. Unfortunately Matt > doesn't work for us anymore and none of us has experience with the > BPF code, so somebody (possibly me) will need to spend a bit of time > figuring it out before verifying that is correct. > > Do you have a test case/suite by any chance ? > > Ben. > >>> This patch brings JIT support for PPC64 >>> >>> Signed-off-by: Vladimir Murzin <[email protected]> >>> --- >>> arch/powerpc/net/bpf_jit_comp.c | 22 ++++++++++++++++++++++ >>> 1 file changed, 22 insertions(+) >>> >>> diff --git a/arch/powerpc/net/bpf_jit_comp.c >>> b/arch/powerpc/net/bpf_jit_comp.c >>> index bf56e33..96f24dc 100644 >>> --- a/arch/powerpc/net/bpf_jit_comp.c >>> +++ b/arch/powerpc/net/bpf_jit_comp.c >>> @@ -193,6 +193,28 @@ static int bpf_jit_build_body(struct sk_filter *fp, >>> u32 *image, >>> PPC_MUL(r_A, r_A, r_scratch1); >>> } >>> break; >>> + case BPF_S_ALU_MOD_X: /* A %= X; */ >>> + ctx->seen |= SEEN_XREG; >>> + PPC_CMPWI(r_X, 0); >>> + if (ctx->pc_ret0 != -1) { >>> + PPC_BCC(COND_EQ, addrs[ctx->pc_ret0]); >>> + } else { >>> + PPC_BCC_SHORT(COND_NE, (ctx->idx*4)+12); >>> + PPC_LI(r_ret, 0); >>> + PPC_JMP(exit_addr); >>> + } >>> + PPC_DIVWU(r_scratch1, r_A, r_X); >>> + PPC_MUL(r_scratch1, r_X, r_scratch1); >>> + PPC_SUB(r_A, r_A, r_scratch1); >>> + break; Without having compiled & tested this, it looks fine to me (especially with the corrected DIVWU opcode in the other patch, oops...). >>> + case BPF_S_ALU_MOD_K: /* A %= K; */ >>> +#define r_scratch2 (r_scratch1 + 1) >>> + PPC_LI32(r_scratch2, K); >>> + PPC_DIVWU(r_scratch1, r_A, r_scratch2); >>> + PPC_MUL(r_scratch1, r_scratch2, r_scratch1); >>> + PPC_SUB(r_A, r_A, r_scratch1); >>> +#undef r_scratch2 >>> + break; If you need another scratch register, it should really be defined in bpf_jit.h instead. Once you define r_scratch2 in there, Acked-by: Matt Evans <[email protected]> Thanks! Matt >>> case BPF_S_ALU_DIV_X: /* A /= X; */ >>> ctx->seen |= SEEN_XREG; >>> PPC_CMPWI(r_X, 0); >>> -- >>> 1.8.1.5 >>> > _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
