powerpc/bpf: Support MOD operation

commit b6069a9570 (filter: add MOD operation) added generic
support for modulus operation in BPF.

This patch brings JIT support for PPC64

Signed-off-by: Vladimir Murzin <murzin.v@gmail.com>
Acked-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index 0baf2b826e25cf1345a6f950ad861f6274895dc3..9aee27c582dcbcbd34a7f9acd2f0aabe6ffb3445 100644 (file)
--- a/arch/powerpc/net/bpf_jit.h
+++ b/arch/powerpc/net/bpf_jit.h
@@ -39,6 +39,7 @@
 #define r_X            5
 #define r_addr         6
 #define r_scratch1     7
+#define r_scratch2     8
 #define r_D            14
 #define r_HL           15
 #define r_M            16

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 81cd6c79babeb79c8d3904f12a890bfb6e99aa64..475d4f26fc6e0de98526529511cfcf29e74b4a43 100644 (file)
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -187,6 +187,26 @@ 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;
+               case BPF_S_ALU_MOD_K: /* A %= K; */
+                       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);
+                       break;
                case BPF_S_ALU_DIV_X: /* A /= X; */
                        ctx->seen |= SEEN_XREG;
                        PPC_CMPWI(r_X, 0);