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, bpf@vger.kernel.org
Subject: [PATCH bpf-next 3/8] riscv, bpf: add support for far jumps and exits
Date: Mon, 9 Dec 2019 18:31:31 +0100 [thread overview]
Message-ID: <20191209173136.29615-4-bjorn.topel@gmail.com> (raw)
In-Reply-To: <20191209173136.29615-1-bjorn.topel@gmail.com>
This commit add support for far (offset > 21b) jumps and exits.
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 e2f6724b64f7..e9cc9832ac2c 100644
--- a/arch/riscv/net/bpf_jit_comp.c
+++ b/arch/riscv/net/bpf_jit_comp.c
@@ -506,16 +506,6 @@ static int is_13b_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,
@@ -733,6 +723,21 @@ 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);
+}
+
/* return -1 or inverted cond */
static int invert_bpf_cond(u8 cond)
{
@@ -1117,13 +1122,7 @@ 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 */
@@ -1261,9 +1260,7 @@ 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:[~2019-12-09 17:31 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-09 17:31 [PATCH bpf-next 0/8] riscv: BPF JIT fix, optimizations and far jumps support Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 1/8] riscv, bpf: fix broken BPF tail calls Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 2/8] riscv, bpf: add support for far branching Björn Töpel
2019-12-09 21:08 ` Luke Nelson
2019-12-09 21:27 ` Daniel Borkmann
2019-12-10 7:02 ` Luke Nelson
2019-12-10 5:32 ` Björn Töpel
2019-12-10 5:31 ` Björn Töpel
2019-12-09 17:31 ` Björn Töpel [this message]
2019-12-09 21:15 ` [PATCH bpf-next 3/8] riscv, bpf: add support for far jumps and exits Luke Nelson
2019-12-09 17:31 ` [PATCH bpf-next 4/8] riscv, bpf: optimize BPF tail calls Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 5/8] riscv, bpf: provide RISC-V specific JIT image alloc/free Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 6/8] riscv, bpf: optimize calls Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 7/8] riscv, bpf: add missing uapi header for BPF_PROG_TYPE_PERF_EVENT programs Björn Töpel
2019-12-09 17:31 ` [PATCH bpf-next 8/8] riscv, perf: add arch specific perf_arch_bpf_user_pt_regs Björn Töpel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191209173136.29615-4-bjorn.topel@gmail.com \
--to=bjorn.topel@gmail.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=linux-riscv@lists.infradead.org \
--cc=netdev@vger.kernel.org \
--subject='Re: [PATCH bpf-next 3/8] riscv, bpf: add support for far jumps and exits' \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).