Commit 65112709 authored by Hari Bathini's avatar Hari Bathini Committed by Michael Ellerman
Browse files

powerpc/bpf/64: add support for BPF_ATOMIC bitwise operations 



Adding instructions for ppc64 for

atomic[64]_and
atomic[64]_or
atomic[64]_xor

Signed-off-by: default avatarHari Bathini <hbathini@linux.ibm.com>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> (ppc64le)
Reviewed-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220610155552.25892-2-hbathini@linux.ibm.com
parent 61bdbca8

arch/powerpc/net/bpf_jit_comp64.c

+29 −28
Original line number Diff line number Diff line
@@ -777,41 +777,42 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * 
		 * BPF_STX ATOMIC (atomic ops)

		 */

		case BPF_STX | BPF_ATOMIC | BPF_W:

			if (imm != BPF_ADD) {

				pr_err_ratelimited(

					"eBPF filter atomic op code %02x (@%d) unsupported\n",

					code, i);

				return -ENOTSUPP;

			}



			/* *(u32 *)(dst + off) += src */



			/* Get EA into TMP_REG_1 */

			EMIT(PPC_RAW_ADDI(tmp1_reg, dst_reg, off));

		case BPF_STX | BPF_ATOMIC | BPF_DW:

			/* Get offset into TMP_REG_1 */

			EMIT(PPC_RAW_LI(tmp1_reg, off));

			tmp_idx = ctx->idx * 4;

			/* load value from memory into TMP_REG_2 */

			EMIT(PPC_RAW_LWARX(tmp2_reg, 0, tmp1_reg, 0));

			/* add value from src_reg into this */

			if (size == BPF_DW)

				EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0));

			else

				EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));



			switch (imm) {

			case BPF_ADD:

				EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));

			/* store result back */

			EMIT(PPC_RAW_STWCX(tmp2_reg, 0, tmp1_reg));

			/* we're done if this succeeded */

			PPC_BCC_SHORT(COND_NE, tmp_idx);

				break;

		case BPF_STX | BPF_ATOMIC | BPF_DW:

			if (imm != BPF_ADD) {

			case BPF_AND:

				EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));

				break;

			case BPF_OR:

				EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));

				break;

			case BPF_XOR:

				EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));

				break;

			default:

				pr_err_ratelimited(

					"eBPF filter atomic op code %02x (@%d) unsupported\n",

					code, i);

				return -ENOTSUPP;

				return -EOPNOTSUPP;

			}

			/* *(u64 *)(dst + off) += src */



			EMIT(PPC_RAW_ADDI(tmp1_reg, dst_reg, off));

			tmp_idx = ctx->idx * 4;

			EMIT(PPC_RAW_LDARX(tmp2_reg, 0, tmp1_reg, 0));

			EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));

			EMIT(PPC_RAW_STDCX(tmp2_reg, 0, tmp1_reg));

			/* store result back */

			if (size == BPF_DW)

				EMIT(PPC_RAW_STDCX(tmp2_reg, tmp1_reg, dst_reg));

			else

				EMIT(PPC_RAW_STWCX(tmp2_reg, tmp1_reg, dst_reg));

			/* we're done if this succeeded */

			PPC_BCC_SHORT(COND_NE, tmp_idx);

			break;