| Message ID | 20191216091343.23260-4-bjorn.topel@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | riscv: BPF JIT fix, optimizations and far jumps support | expand |
On Mon, 16 Dec 2019 01:13:37 PST (-0800), Bjorn Topel wrote: > Start use the emit_branch() function in the tail call emitter in order > to support far branching. > > Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> > --- > arch/riscv/net/bpf_jit_comp.c | 22 +++------------------- > 1 file changed, 3 insertions(+), 19 deletions(-) > > diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c > index e599458a9bcd..c38c95df3440 100644 > --- a/arch/riscv/net/bpf_jit_comp.c > +++ b/arch/riscv/net/bpf_jit_comp.c > @@ -496,16 +496,6 @@ static int is_12b_check(int off, int insn) > return 0; > } > > -static int is_13b_check(int off, int insn) > -{ > - if (!is_13b_int(off)) { > - pr_err("bpf-jit: insn=%d 13b < offset=%d not supported yet!\n", > - insn, (int)off); > - return -1; > - } > - return 0; > -} > - > static int is_21b_check(int off, int insn) > { > if (!is_21b_int(off)) { > @@ -744,18 +734,14 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) > return -1; > emit(rv_lwu(RV_REG_T1, off, RV_REG_A1), ctx); > off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; > - if (is_13b_check(off, insn)) > - return -1; > - emit(rv_bgeu(RV_REG_A2, RV_REG_T1, off >> 1), ctx); > + emit_branch(BPF_JGE, RV_REG_A2, RV_REG_T1, off, ctx); > > /* if (--TCC < 0) > * goto out; > */ > emit(rv_addi(RV_REG_T1, tcc, -1), ctx); > off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; > - if (is_13b_check(off, insn)) > - return -1; > - emit(rv_blt(RV_REG_T1, RV_REG_ZERO, off >> 1), ctx); > + emit_branch(BPF_JSLT, RV_REG_T1, RV_REG_ZERO, off, ctx); > > /* prog = array->ptrs[index]; > * if (!prog) > @@ -768,9 +754,7 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) > return -1; > emit(rv_ld(RV_REG_T2, off, RV_REG_T2), ctx); > off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; > - if (is_13b_check(off, insn)) > - return -1; > - emit(rv_beq(RV_REG_T2, RV_REG_ZERO, off >> 1), ctx); > + emit_branch(BPF_JEQ, RV_REG_T2, RV_REG_ZERO, off, ctx); > > /* goto *(prog->bpf_func + 4); */ > off = offsetof(struct bpf_prog, bpf_func); Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c index e599458a9bcd..c38c95df3440 100644 --- a/arch/riscv/net/bpf_jit_comp.c +++ b/arch/riscv/net/bpf_jit_comp.c @@ -496,16 +496,6 @@ static int is_12b_check(int off, int insn) return 0; } -static int is_13b_check(int off, int insn) -{ - if (!is_13b_int(off)) { - pr_err("bpf-jit: insn=%d 13b < offset=%d not supported yet!\n", - insn, (int)off); - return -1; - } - return 0; -} - static int is_21b_check(int off, int insn) { if (!is_21b_int(off)) { @@ -744,18 +734,14 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) return -1; emit(rv_lwu(RV_REG_T1, off, RV_REG_A1), ctx); off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; - if (is_13b_check(off, insn)) - return -1; - emit(rv_bgeu(RV_REG_A2, RV_REG_T1, off >> 1), ctx); + emit_branch(BPF_JGE, RV_REG_A2, RV_REG_T1, off, ctx); /* if (--TCC < 0) * goto out; */ emit(rv_addi(RV_REG_T1, tcc, -1), ctx); off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; - if (is_13b_check(off, insn)) - return -1; - emit(rv_blt(RV_REG_T1, RV_REG_ZERO, off >> 1), ctx); + emit_branch(BPF_JSLT, RV_REG_T1, RV_REG_ZERO, off, ctx); /* prog = array->ptrs[index]; * if (!prog) @@ -768,9 +754,7 @@ static int emit_bpf_tail_call(int insn, struct rv_jit_context *ctx) return -1; emit(rv_ld(RV_REG_T2, off, RV_REG_T2), ctx); off = (tc_ninsn - (ctx->ninsns - start_insn)) << 2; - if (is_13b_check(off, insn)) - return -1; - emit(rv_beq(RV_REG_T2, RV_REG_ZERO, off >> 1), ctx); + emit_branch(BPF_JEQ, RV_REG_T2, RV_REG_ZERO, off, ctx); /* goto *(prog->bpf_func + 4); */ off = offsetof(struct bpf_prog, bpf_func);
Start use the emit_branch() function in the tail call emitter in order to support far branching. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> --- arch/riscv/net/bpf_jit_comp.c | 22 +++------------------- 1 file changed, 3 insertions(+), 19 deletions(-)