[PATCH bpf-next 3/7] riscv, bpf: Support sign-extension mov insns

From: Pu Lehui
Date: Wed Aug 23 2023 - 11:07:09 EST


From: Pu Lehui <pulehui@xxxxxxxxxx>

Add support sign-extension mov instructions for RV64.

Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx>
---
arch/riscv/net/bpf_jit_comp64.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index fd36cb17101a..d1497182cacf 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -1047,7 +1047,19 @@ int bpf_jit_emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
emit_zext_32(rd, ctx);
break;
}
- emit_mv(rd, rs, ctx);
+ switch (insn->off) {
+ case 0:
+ emit_mv(rd, rs, ctx);
+ break;
+ case 8:
+ case 16:
+ emit_slli(rs, rs, 64 - insn->off, ctx);
+ emit_srai(rd, rs, 64 - insn->off, ctx);
+ break;
+ case 32:
+ emit_addiw(rd, rs, 0, ctx);
+ break;
+ }
if (!is64 && !aux->verifier_zext)
emit_zext_32(rd, ctx);
break;
--
2.39.2