[PATCH v5 bpf-next 12/17] powerpc: bpf: eliminate zero extension code-gen

[Jiong Wang <jiong.wang@netronome.com>]

Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
---
 arch/powerpc/net/bpf_jit_comp64.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 21a1dcd..2266c7c 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -557,9 +557,15 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
 				goto bpf_alu32_trunc;
 			break;
 
+		/*
+		 * ZEXT, does low 32-bit zero extension unconditionally
+		 */
+		case BPF_ALU | BPF_ZEXT:
+			PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31);
+			break;
 bpf_alu32_trunc:
 		/* Truncate to 32-bits */
-		if (BPF_CLASS(code) == BPF_ALU)
+		if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext)
 			PPC_RLWINM(dst_reg, dst_reg, 0, 0, 31);
 		break;
 
@@ -1046,6 +1052,11 @@ struct powerpc64_jit_data {
 	struct codegen_context ctx;
 };
 
+bool bpf_jit_hardware_zext(void)
+{
+	return false;
+}
+
 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 {
 	u32 proglen;
-- 
2.7.4