[RFC bpf-next 3/7] ppc: bpf: implement jitting of BPF_ALU | BPF_ARSH | BPF_*

[Jiong Wang]

This patch implements code-gen for BPF_ALU | BPF_ARSH | BPF_*.

Cc: Naveen N. Rao <naveen.n....@linux.ibm.com>
Cc: Sandipan Das <sandi...@linux.ibm.com>
Signed-off-by: Jiong Wang <jiong.w...@netronome.com>
---
 arch/powerpc/include/asm/ppc-opcode.h | 2 ++
 arch/powerpc/net/bpf_jit.h            | 4 ++++
 arch/powerpc/net/bpf_jit_comp64.c     | 6 ++++++
 3 files changed, 12 insertions(+)

diff --git a/arch/powerpc/include/asm/ppc-opcode.h 
b/arch/powerpc/include/asm/ppc-opcode.h
index a6e9e31..9014592 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -342,6 +342,8 @@
 #define PPC_INST_SLW                   0x7c000030
 #define PPC_INST_SLD                   0x7c000036
 #define PPC_INST_SRW                   0x7c000430
+#define PPC_INST_SRAW                  0x7c000630
+#define PPC_INST_SRAWI                 0x7c000670
 #define PPC_INST_SRD                   0x7c000436
 #define PPC_INST_SRAD                  0x7c000634
 #define PPC_INST_SRADI                 0x7c000674
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index 47fc666..c2d5192 100644
--- a/arch/powerpc/net/bpf_jit.h
+++ b/arch/powerpc/net/bpf_jit.h
@@ -152,6 +152,10 @@
                                     ___PPC_RS(a) | ___PPC_RB(s))
 #define PPC_SRW(d, a, s)       EMIT(PPC_INST_SRW | ___PPC_RA(d) |            \
                                     ___PPC_RS(a) | ___PPC_RB(s))
+#define PPC_SRAW(d, a, s)      EMIT(PPC_INST_SRAW | ___PPC_RA(d) |           \
+                                    ___PPC_RS(a) | ___PPC_RB(s))
+#define PPC_SRAWI(d, a, i)     EMIT(PPC_INST_SRAWI | ___PPC_RA(d) |          \
+                                    ___PPC_RS(a) | __PPC_SH(i))
 #define PPC_SRD(d, a, s)       EMIT(PPC_INST_SRD | ___PPC_RA(d) |            \
                                     ___PPC_RS(a) | ___PPC_RB(s))
 #define PPC_SRAD(d, a, s)      EMIT(PPC_INST_SRAD | ___PPC_RA(d) |           \
diff --git a/arch/powerpc/net/bpf_jit_comp64.c 
b/arch/powerpc/net/bpf_jit_comp64.c
index 17482f5..c685b4f 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -529,9 +529,15 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 
*image,
                        if (imm != 0)
                                PPC_SRDI(dst_reg, dst_reg, imm);
                        break;
+               case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */
+                       PPC_SRAW(dst_reg, dst_reg, src_reg);
+                       break;
                case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
                        PPC_SRAD(dst_reg, dst_reg, src_reg);
                        break;
+               case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */
+                       PPC_SRAWI(dst_reg, dst_reg, imm);
+                       break;
                case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
                        if (imm != 0)
                                PPC_SRADI(dst_reg, dst_reg, imm);
-- 
2.7.4