nfp: bpf: implement byte swap instruction

Implement byte swaps with rotations, shifts and byte loads.
Remember to clear upper parts of the 64 bit registers.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index 4f7cfa6adfc134fa4e2d06307124d22c49212ae5..5e8a6b7667908b005a01cf17c6565f42c8634ade 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -746,6 +746,14 @@ wrp_cmp_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
        return 0;
 }
 
+static void wrp_end32(struct nfp_prog *nfp_prog, swreg reg_in, u8 gpr_out)
+{
+       emit_ld_field(nfp_prog, reg_both(gpr_out), 0xf, reg_in,
+                     SHF_SC_R_ROT, 8);
+       emit_ld_field(nfp_prog, reg_both(gpr_out), 0x5, reg_a(gpr_out),
+                     SHF_SC_R_ROT, 16);
+}
+
 /* --- Callbacks --- */
 static int mov_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {
@@ -982,6 +990,35 @@ static int shl_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
        return 0;
 }
 
+static int end_reg32(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+       const struct bpf_insn *insn = &meta->insn;
+       u8 gpr = insn->dst_reg * 2;
+
+       switch (insn->imm) {
+       case 16:
+               emit_ld_field(nfp_prog, reg_both(gpr), 0x9, reg_b(gpr),
+                             SHF_SC_R_ROT, 8);
+               emit_ld_field(nfp_prog, reg_both(gpr), 0xe, reg_a(gpr),
+                             SHF_SC_R_SHF, 16);
+
+               wrp_immed(nfp_prog, reg_both(gpr + 1), 0);
+               break;
+       case 32:
+               wrp_end32(nfp_prog, reg_a(gpr), gpr);
+               wrp_immed(nfp_prog, reg_both(gpr + 1), 0);
+               break;
+       case 64:
+               wrp_mov(nfp_prog, imm_a(nfp_prog), reg_b(gpr + 1));
+
+               wrp_end32(nfp_prog, reg_a(gpr), gpr + 1);
+               wrp_end32(nfp_prog, imm_a(nfp_prog), gpr);
+               break;
+       }
+
+       return 0;
+}
+
 static int imm_ld8_part2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
 {
        wrp_immed(nfp_prog, reg_both(nfp_meta_prev(meta)->insn.dst_reg * 2 + 1),
@@ -1297,6 +1334,7 @@ static const instr_cb_t instr_cb[256] = {
        [BPF_ALU | BPF_SUB | BPF_X] =   sub_reg,
        [BPF_ALU | BPF_SUB | BPF_K] =   sub_imm,
        [BPF_ALU | BPF_LSH | BPF_K] =   shl_imm,
+       [BPF_ALU | BPF_END | BPF_X] =   end_reg32,
        [BPF_LD | BPF_IMM | BPF_DW] =   imm_ld8,
        [BPF_LD | BPF_ABS | BPF_B] =    data_ld1,
        [BPF_LD | BPF_ABS | BPF_H] =    data_ld2,