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Commit 84708c13 authored by Jiong Wang's avatar Jiong Wang Committed by Alexei Starovoitov
Browse files

nfp: bpf: implement jitting of BPF_ALU | BPF_ARSH | BPF_* 



BPF_X support needs indirect shift mode, please see code comments for
details.

Reviewed-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarJiong Wang <jiong.wang@netronome.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f860203b

drivers/net/ethernet/netronome/nfp/bpf/jit.c

+45 −0
Original line number Diff line number Diff line
@@ -2382,6 +2382,49 @@ static int neg_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) 
	return 0;

}



static int __ashr_imm(struct nfp_prog *nfp_prog, u8 dst, u8 shift_amt)

{

	/* Set signedness bit (MSB of result). */

	emit_alu(nfp_prog, reg_none(), reg_a(dst), ALU_OP_OR, reg_imm(0));

	emit_shf(nfp_prog, reg_both(dst), reg_none(), SHF_OP_ASHR, reg_b(dst),

		 SHF_SC_R_SHF, shift_amt);

	wrp_immed(nfp_prog, reg_both(dst + 1), 0);



	return 0;

}



static int ashr_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)

{

	const struct bpf_insn *insn = &meta->insn;

	u64 umin, umax;

	u8 dst, src;



	dst = insn->dst_reg * 2;

	umin = meta->umin_src;

	umax = meta->umax_src;

	if (umin == umax)

		return __ashr_imm(nfp_prog, dst, umin);



	src = insn->src_reg * 2;

	/* NOTE: the first insn will set both indirect shift amount (source A)

	 * and signedness bit (MSB of result).

	 */

	emit_alu(nfp_prog, reg_none(), reg_a(src), ALU_OP_OR, reg_b(dst));

	emit_shf_indir(nfp_prog, reg_both(dst), reg_none(), SHF_OP_ASHR,

		       reg_b(dst), SHF_SC_R_SHF);

	wrp_immed(nfp_prog, reg_both(dst + 1), 0);



	return 0;

}



static int ashr_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)

{

	const struct bpf_insn *insn = &meta->insn;

	u8 dst = insn->dst_reg * 2;



	return __ashr_imm(nfp_prog, dst, insn->imm);

}



static int shl_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)

{

	const struct bpf_insn *insn = &meta->insn;
@@ -3286,6 +3329,8 @@ static const instr_cb_t instr_cb[256] = { 
	[BPF_ALU | BPF_DIV | BPF_K] =	div_imm,

	[BPF_ALU | BPF_NEG] =		neg_reg,

	[BPF_ALU | BPF_LSH | BPF_K] =	shl_imm,

	[BPF_ALU | BPF_ARSH | BPF_X] =	ashr_reg,

	[BPF_ALU | BPF_ARSH | BPF_K] =	ashr_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,