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From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: ykaliuta@redhat.com, johan.almbladh@anyfinetworks.com,
	linuxppc-dev@lists.ozlabs.org, song@kernel.org,
	bpf@vger.kernel.org, Jiri Olsa <jolsa@redhat.com>,
	Hari Bathini <hbathini@linux.ibm.com>
Subject: [PATCH 09/13] powerpc64/bpf: Do not save/restore LR on each call to bpf_stf_barrier()
Date: Thu,  6 Jan 2022 17:15:13 +0530	[thread overview]
Message-ID: <5e0238a782acfa118a1b5e7cbbe0c7a508122bc0.1641468127.git.naveen.n.rao@linux.vnet.ibm.com> (raw)
In-Reply-To: <cover.1641468127.git.naveen.n.rao@linux.vnet.ibm.com>

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@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 7d38b4be26c3a5..ce4fc59bbd6a92 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;
-- 
2.34.1


  parent reply	other threads:[~2022-01-06 11:53 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-06 11:45 [PATCH 00/13] powerpc/bpf: Some fixes and updates Naveen N. Rao
2022-01-06 11:45 ` [PATCH 01/13] bpf: Guard against accessing NULL pt_regs in bpf_get_task_stack() Naveen N. Rao
2022-01-07 10:21   ` Daniel Borkmann
2022-01-10  8:57   ` Christophe Leroy
2022-01-10 10:36     ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 02/13] powerpc32/bpf: Fix codegen for bpf-to-bpf calls Naveen N. Rao
2022-01-10  9:06   ` Christophe Leroy
2022-01-10 10:52     ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 03/13] powerpc/bpf: Update ldimm64 instructions during extra pass Naveen N. Rao
2022-01-08 14:45   ` Jiri Olsa
2022-01-10  9:27   ` Christophe Leroy
2022-01-10 10:56     ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 04/13] tools/bpf: Rename 'struct event' to avoid naming conflict Naveen N. Rao
2022-01-07 10:21   ` Daniel Borkmann
2022-01-06 11:45 ` [PATCH 05/13] powerpc/bpf: Skip branch range validation during first pass Naveen N. Rao
2022-01-06 11:45 ` [PATCH 06/13] powerpc/bpf: Emit a single branch instruction for known short branch ranges Naveen N. Rao
2022-01-06 11:45 ` [PATCH 07/13] powerpc/bpf: Handle large branch ranges with BPF_EXIT Naveen N. Rao
2022-01-06 11:45 ` [PATCH 08/13] powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 Naveen N. Rao
2022-01-06 11:45 ` Naveen N. Rao [this message]
2022-01-06 11:45 ` [PATCH 10/13] powerpc64/bpf: Use r12 for constant blinding Naveen N. Rao
2022-01-06 11:45 ` [PATCH 11/13] powerpc64/bpf elfv2: Setup kernel TOC in r2 on entry Naveen N. Rao
2022-01-10  9:20   ` Christophe Leroy
2022-01-11 10:31     ` Naveen N. Rao
2022-01-11 14:35       ` Christophe Leroy
2022-01-11 14:43         ` Christophe Leroy
2022-01-14 11:17           ` Naveen N. Rao
2022-01-06 11:45 ` [PATCH 12/13] powerpc64/bpf elfv1: Do not load TOC before calling functions Naveen N. Rao
2022-01-06 11:45 ` [PATCH 13/13] powerpc64/bpf: Optimize instruction sequence used for function calls Naveen N. Rao
2022-01-06 21:46 ` [PATCH 00/13] powerpc/bpf: Some fixes and updates Daniel Borkmann
2022-01-07  7:36   ` Naveen N. Rao
2022-01-07 10:20     ` Daniel Borkmann
2022-01-10  3:47       ` Michael Ellerman
2022-01-16 10:41 ` Michael Ellerman

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