[PATCH powerpc/next 04/17] powerpc64/bpf: Do not save/restore LR on each call to bpf_stf_barrier()

Naveen N. Rao naveen.n.rao at linux.vnet.ibm.com
Mon Feb 14 21:41:38 AEDT 2022


Instead of saving and restoring LR before each invocation to
bpf_stf_barrier(), set SEEN_FUNC flag so that we save/restore LR in
prologue/epilogue.

Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
 arch/powerpc/net/bpf_jit_comp64.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 371bd5a16859c7..27ac2fc7670298 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -690,11 +690,10 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *
 				EMIT(PPC_RAW_ORI(_R31, _R31, 0));
 				break;
 			case STF_BARRIER_FALLBACK:
-				EMIT(PPC_RAW_MFLR(b2p[TMP_REG_1]));
+				ctx->seen |= SEEN_FUNC;
 				PPC_LI64(12, dereference_kernel_function_descriptor(bpf_stf_barrier));
 				EMIT(PPC_RAW_MTCTR(12));
 				EMIT(PPC_RAW_BCTRL());
-				EMIT(PPC_RAW_MTLR(b2p[TMP_REG_1]));
 				break;
 			case STF_BARRIER_NONE:
 				break;
-- 
2.35.1



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