Commit c2067f7f authored by Naveen N Rao's avatar Naveen N Rao Committed by Michael Ellerman
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powerpc64/bpf: Do not save/restore LR on each call to bpf_stf_barrier() 



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: 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/4446f25478d82a2a4ac9dab2ebdfd88ddf923eb7.1644834730.git.naveen.n.rao@linux.vnet.ibm.com
parent 0ffdbce6

arch/powerpc/net/bpf_jit_comp64.c

+1 −2
Original line number Diff line number Diff line
@@ -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;