Commit 591006b9 authored by Jiong Wang's avatar Jiong Wang Committed by Alexei Starovoitov
Browse files

s390: bpf: eliminate zero extension code-gen 



Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarJiong Wang <jiong.wang@netronome.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent a4c92773

arch/s390/net/bpf_jit_comp.c

+34 −7
Original line number Diff line number Diff line
@@ -299,9 +299,11 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) 


#define EMIT_ZERO(b1)						\

({								\

	if (!fp->aux->verifier_zext) {				\

		/* llgfr %dst,%dst (zero extend to 64 bit) */	\

		EMIT4(0xb9160000, b1, b1);			\

		REG_SET_SEEN(b1);				\

	}							\

})



/*
@@ -520,6 +522,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 
	case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */

		/* llgfr %dst,%src */

		EMIT4(0xb9160000, dst_reg, src_reg);

		if (insn_is_zext(&insn[1]))

			insn_count = 2;

		break;

	case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */

		/* lgr %dst,%src */
@@ -528,6 +532,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 
	case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */

		/* llilf %dst,imm */

		EMIT6_IMM(0xc00f0000, dst_reg, imm);

		if (insn_is_zext(&insn[1]))

			insn_count = 2;

		break;

	case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */

		/* lgfi %dst,imm */
@@ -639,6 +645,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 
		EMIT4(0xb9970000, REG_W0, src_reg);

		/* llgfr %dst,%rc */

		EMIT4(0xb9160000, dst_reg, rc_reg);

		if (insn_is_zext(&insn[1]))

			insn_count = 2;

		break;

	}

	case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
@@ -676,6 +684,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 
			      EMIT_CONST_U32(imm));

		/* llgfr %dst,%rc */

		EMIT4(0xb9160000, dst_reg, rc_reg);

		if (insn_is_zext(&insn[1]))

			insn_count = 2;

		break;

	}

	case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
@@ -864,8 +874,11 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 
		case 16: /* dst = (u16) cpu_to_be16(dst) */

			/* llghr %dst,%dst */

			EMIT4(0xb9850000, dst_reg, dst_reg);

			if (insn_is_zext(&insn[1]))

				insn_count = 2;

			break;

		case 32: /* dst = (u32) cpu_to_be32(dst) */

			if (!fp->aux->verifier_zext)

				/* llgfr %dst,%dst */

				EMIT4(0xb9160000, dst_reg, dst_reg);

			break;
@@ -882,10 +895,13 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 
			EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);

			/* llghr %dst,%dst */

			EMIT4(0xb9850000, dst_reg, dst_reg);

			if (insn_is_zext(&insn[1]))

				insn_count = 2;

			break;

		case 32: /* dst = (u32) cpu_to_le32(dst) */

			/* lrvr %dst,%dst */

			EMIT4(0xb91f0000, dst_reg, dst_reg);

			if (!fp->aux->verifier_zext)

				/* llgfr %dst,%dst */

				EMIT4(0xb9160000, dst_reg, dst_reg);

			break;
@@ -968,16 +984,22 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i 
		/* llgc %dst,0(off,%src) */

		EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);

		jit->seen |= SEEN_MEM;

		if (insn_is_zext(&insn[1]))

			insn_count = 2;

		break;

	case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */

		/* llgh %dst,0(off,%src) */

		EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);

		jit->seen |= SEEN_MEM;

		if (insn_is_zext(&insn[1]))

			insn_count = 2;

		break;

	case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */

		/* llgf %dst,off(%src) */

		jit->seen |= SEEN_MEM;

		EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);

		if (insn_is_zext(&insn[1]))

			insn_count = 2;

		break;

	case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */

		/* lg %dst,0(off,%src) */
@@ -1282,6 +1304,11 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp) 
	return 0;

}



bool bpf_jit_needs_zext(void)

{

	return true;

}



/*

 * Compile eBPF program "fp"

 */