From bafb5898de5d2f15133774cb049fe55720b9c92f Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Mon, 14 Feb 2022 16:11:36 +0530 Subject: powerpc/bpf: Emit a single branch instruction for known short branch ranges PPC_BCC() emits two instructions to accommodate scenarios where we need to branch outside the range of a conditional branch. PPC_BCC_SHORT() emits a single branch instruction and can be used when the branch is known to be within a conditional branch range. Convert some of the uses of PPC_BCC() in the powerpc BPF JIT over to PPC_BCC_SHORT() where we know the branch range. Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/edbca01377d1d5f472868bf6d8962b0a0d85b96f.1644834730.git.naveen.n.rao@linux.vnet.ibm.com --- arch/powerpc/net/bpf_jit_comp32.c | 8 ++++---- arch/powerpc/net/bpf_jit_comp64.c | 8 ++++---- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index 43643f1c1034..5ba5340a6387 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -229,7 +229,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o EMIT(PPC_RAW_LWZ(_R0, b2p_bpf_array, offsetof(struct bpf_array, map.max_entries))); EMIT(PPC_RAW_CMPLW(b2p_index, _R0)); EMIT(PPC_RAW_LWZ(_R0, _R1, bpf_jit_stack_offsetof(ctx, BPF_PPC_TC))); - PPC_BCC(COND_GE, out); + PPC_BCC_SHORT(COND_GE, out); /* * if (tail_call_cnt >= MAX_TAIL_CALL_CNT) @@ -238,7 +238,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o EMIT(PPC_RAW_CMPLWI(_R0, MAX_TAIL_CALL_CNT)); /* tail_call_cnt++; */ EMIT(PPC_RAW_ADDIC(_R0, _R0, 1)); - PPC_BCC(COND_GE, out); + PPC_BCC_SHORT(COND_GE, out); /* prog = array->ptrs[index]; */ EMIT(PPC_RAW_RLWINM(_R3, b2p_index, 2, 0, 29)); @@ -251,7 +251,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o * goto out; */ EMIT(PPC_RAW_CMPLWI(_R3, 0)); - PPC_BCC(COND_EQ, out); + PPC_BCC_SHORT(COND_EQ, out); /* goto *(prog->bpf_func + prologue_size); */ EMIT(PPC_RAW_LWZ(_R3, _R3, offsetof(struct bpf_prog, bpf_func))); @@ -842,7 +842,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * if (BPF_MODE(code) == BPF_PROBE_MEM) { PPC_LI32(_R0, TASK_SIZE - off); EMIT(PPC_RAW_CMPLW(src_reg, _R0)); - PPC_BCC(COND_GT, (ctx->idx + 5) * 4); + PPC_BCC_SHORT(COND_GT, (ctx->idx + 4) * 4); EMIT(PPC_RAW_LI(dst_reg, 0)); /* * For BPF_DW case, "li reg_h,0" would be needed when diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index e1e8c934308a..b1ed8611091d 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -225,7 +225,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o EMIT(PPC_RAW_LWZ(b2p[TMP_REG_1], b2p_bpf_array, offsetof(struct bpf_array, map.max_entries))); EMIT(PPC_RAW_RLWINM(b2p_index, b2p_index, 0, 0, 31)); EMIT(PPC_RAW_CMPLW(b2p_index, b2p[TMP_REG_1])); - PPC_BCC(COND_GE, out); + PPC_BCC_SHORT(COND_GE, out); /* * if (tail_call_cnt >= MAX_TAIL_CALL_CNT) @@ -233,7 +233,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o */ PPC_BPF_LL(b2p[TMP_REG_1], 1, bpf_jit_stack_tailcallcnt(ctx)); EMIT(PPC_RAW_CMPLWI(b2p[TMP_REG_1], MAX_TAIL_CALL_CNT)); - PPC_BCC(COND_GE, out); + PPC_BCC_SHORT(COND_GE, out); /* * tail_call_cnt++; @@ -251,7 +251,7 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o * goto out; */ EMIT(PPC_RAW_CMPLDI(b2p[TMP_REG_1], 0)); - PPC_BCC(COND_EQ, out); + PPC_BCC_SHORT(COND_EQ, out); /* goto *(prog->bpf_func + prologue_size); */ PPC_BPF_LL(b2p[TMP_REG_1], b2p[TMP_REG_1], offsetof(struct bpf_prog, bpf_func)); @@ -807,7 +807,7 @@ emit_clear: else /* BOOK3S_64 */ PPC_LI64(b2p[TMP_REG_2], PAGE_OFFSET); EMIT(PPC_RAW_CMPLD(b2p[TMP_REG_1], b2p[TMP_REG_2])); - PPC_BCC(COND_GT, (ctx->idx + 4) * 4); + PPC_BCC_SHORT(COND_GT, (ctx->idx + 3) * 4); EMIT(PPC_RAW_LI(dst_reg, 0)); /* * Check if 'off' is word aligned because PPC_BPF_LL() -- cgit