From: "Björn Töpel" <bjorn.topel@gmail.com>
To: daniel@iogearbox.net, ast@kernel.org, netdev@vger.kernel.org
Cc: "Björn Töpel" <bjorn.topel@gmail.com>,
linux-riscv@lists.infradead.org,
"Luke Nelson" <lukenels@cs.washington.edu>,
bpf@vger.kernel.org, "Xi Wang" <xi.wang@gmail.com>
Subject: [PATCH bpf-next v2 4/9] riscv, bpf: add support for far jumps and exits
Date: Mon, 16 Dec 2019 10:13:38 +0100 [thread overview]
Message-ID: <20191216091343.23260-5-bjorn.topel@gmail.com> (raw)
In-Reply-To: <20191216091343.23260-1-bjorn.topel@gmail.com>
This commit add support for far (offset > 21b) jumps and exits.
Reviewed-by: Luke Nelson <lukenels@cs.washington.edu>
Cc: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
---
arch/riscv/net/bpf_jit_comp.c | 37 ++++++++++++++++-------------------
1 file changed, 17 insertions(+), 20 deletions(-)
diff --git a/arch/riscv/net/bpf_jit_comp.c b/arch/riscv/net/bpf_jit_comp.c
index c38c95df3440..2fc0f24ad30f 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_21b_check(int off, int insn)
-{
- if (!is_21b_int(off)) {
- pr_err("bpf-jit: insn=%d 21b < offset=%d not supported yet!\n",
- insn, (int)off);
- return -1;
- }
- return 0;
-}
-
static void emit_imm(u8 rd, s64 val, struct rv_jit_context *ctx)
{
/* Note that the immediate from the add is sign-extended,
@@ -820,6 +810,21 @@ static void emit_sext_32_rd(u8 *rd, struct rv_jit_context *ctx)
*rd = RV_REG_T2;
}
+static void emit_jump_and_link(u8 rd, int rvoff, struct rv_jit_context *ctx)
+{
+ s64 upper, lower;
+
+ if (is_21b_int(rvoff)) {
+ emit(rv_jal(rd, rvoff >> 1), ctx);
+ return;
+ }
+
+ upper = (rvoff + (1 << 11)) >> 12;
+ lower = rvoff & 0xfff;
+ emit(rv_auipc(RV_REG_T1, upper), ctx);
+ emit(rv_jalr(rd, RV_REG_T1, lower), ctx);
+}
+
static bool is_signed_bpf_cond(u8 cond)
{
return cond == BPF_JSGT || cond == BPF_JSLT ||
@@ -1101,13 +1106,7 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
/* JUMP off */
case BPF_JMP | BPF_JA:
rvoff = rv_offset(i, off, ctx);
- if (!is_21b_int(rvoff)) {
- pr_err("bpf-jit: insn=%d offset=%d not supported yet!\n",
- i, rvoff);
- return -1;
- }
-
- emit(rv_jal(RV_REG_ZERO, rvoff >> 1), ctx);
+ emit_jump_and_link(RV_REG_ZERO, rvoff, ctx);
break;
/* IF (dst COND src) JUMP off */
@@ -1245,9 +1244,7 @@ static int emit_insn(const struct bpf_insn *insn, struct rv_jit_context *ctx,
break;
rvoff = epilogue_offset(ctx);
- if (is_21b_check(rvoff, i))
- return -1;
- emit(rv_jal(RV_REG_ZERO, rvoff >> 1), ctx);
+ emit_jump_and_link(RV_REG_ZERO, rvoff, ctx);
break;
/* dst = imm64 */
--
2.20.1
next prev parent reply other threads:[~2019-12-16 9:14 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-16 9:13 [PATCH bpf-next v2 0/9] riscv: BPF JIT fix, optimizations and far jumps support Björn Töpel
2019-12-16 9:13 ` [PATCH bpf-next v2 1/9] riscv, bpf: fix broken BPF tail calls Björn Töpel
2019-12-16 9:13 ` [PATCH bpf-next v2 2/9] riscv, bpf: add support for far branching Björn Töpel
2019-12-16 9:13 ` [PATCH bpf-next v2 3/9] riscv, bpf: add support for far branching when emitting tail call Björn Töpel
2019-12-16 9:13 ` Björn Töpel [this message]
2019-12-16 9:13 ` [PATCH bpf-next v2 5/9] riscv, bpf: optimize BPF tail calls Björn Töpel
2019-12-16 9:13 ` [PATCH bpf-next v2 6/9] riscv, bpf: provide RISC-V specific JIT image alloc/free Björn Töpel
2019-12-16 15:09 ` Daniel Borkmann
2019-12-18 6:23 ` Björn Töpel
2020-01-04 1:32 ` Paul Walmsley
2020-01-07 10:24 ` Björn Töpel
2020-01-07 10:47 ` Paul Walmsley
2020-02-02 13:37 ` Alex Ghiti
2020-02-03 12:28 ` Björn Töpel
2020-02-03 20:57 ` Alex Ghiti
2019-12-16 9:13 ` [PATCH bpf-next v2 7/9] riscv, bpf: optimize calls Björn Töpel
2019-12-16 9:13 ` [PATCH bpf-next v2 8/9] riscv, bpf: add missing uapi header for BPF_PROG_TYPE_PERF_EVENT programs Björn Töpel
2019-12-16 9:13 ` [PATCH bpf-next v2 9/9] riscv, perf: add arch specific perf_arch_bpf_user_pt_regs Björn Töpel
2019-12-19 15:07 ` [PATCH bpf-next v2 0/9] riscv: BPF JIT fix, optimizations and far jumps support Daniel Borkmann
2019-12-19 22:02 ` [PATCH bpf-next v2 1/9] riscv, bpf: fix broken BPF tail calls Palmer Dabbelt
2019-12-23 18:03 ` [PATCH bpf-next v2 2/9] riscv, bpf: add support for far branching Palmer Dabbelt
2020-01-07 8:13 ` Björn Töpel
2020-01-23 2:08 ` Palmer Dabbelt
2019-12-23 18:18 ` [PATCH bpf-next v2 3/9] riscv, bpf: add support for far branching when emitting tail call Palmer Dabbelt
2019-12-23 18:18 ` [PATCH bpf-next v2 4/9] riscv, bpf: add support for far jumps and exits Palmer Dabbelt
2019-12-23 18:29 ` [PATCH bpf-next v2 5/9] riscv, bpf: optimize BPF tail calls Palmer Dabbelt
2019-12-23 18:30 ` [PATCH bpf-next v2 6/9] riscv, bpf: provide RISC-V specific JIT image alloc/free Palmer Dabbelt
2019-12-23 18:58 ` [PATCH bpf-next v2 7/9] riscv, bpf: optimize calls Palmer Dabbelt
2020-01-07 10:14 ` Björn Töpel
2020-01-28 2:15 ` Palmer Dabbelt
2020-02-03 12:11 ` Björn Töpel
2019-12-23 18:58 ` [PATCH bpf-next v2 8/9] riscv, bpf: add missing uapi header for BPF_PROG_TYPE_PERF_EVENT programs Palmer Dabbelt
2019-12-23 18:58 ` [PATCH bpf-next v2 9/9] riscv, perf: add arch specific perf_arch_bpf_user_pt_regs Palmer Dabbelt
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