powerpc64/bpf: jit support for unconditional byte swap

Add jit support for unconditional byte swap. Tested using BSWAP tests
from test_bpf module.

Signed-off-by: Artem Savkov <asavkov@redhat.com>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240517075650.248801-3-asavkov@redhat.com

Author: sm00th

arch/powerpc/net/bpf_jit_comp64.c

@@ -699,11 +699,12 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code
 		 */
 		case BPF_ALU | BPF_END | BPF_FROM_LE:
 		case BPF_ALU | BPF_END | BPF_FROM_BE:
+		case BPF_ALU64 | BPF_END | BPF_FROM_LE:
 #ifdef __BIG_ENDIAN__
 			if (BPF_SRC(code) == BPF_FROM_BE)
 				goto emit_clear;
 #else /* !__BIG_ENDIAN__ */
-			if (BPF_SRC(code) == BPF_FROM_LE)
+			if (BPF_CLASS(code) == BPF_ALU && BPF_SRC(code) == BPF_FROM_LE)
 				goto emit_clear;
 #endif
 			switch (imm) {