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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 v2 3/9] riscv, bpf: add support for far branching when emitting tail call
Date: Mon, 16 Dec 2019 10:13:37 +0100	[thread overview]
Message-ID: <20191216091343.23260-4-bjorn.topel@gmail.com> (raw)
In-Reply-To: <20191216091343.23260-1-bjorn.topel@gmail.com>

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);
-- 
2.20.1


  parent reply	other threads:[~2019-12-16  9:14 UTC|newest]

Thread overview: 32+ 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 ` Björn Töpel [this message]
2019-12-16  9:13 ` [PATCH bpf-next v2 4/9] riscv, bpf: add support for far jumps and exits Björn Töpel
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
2019-12-23 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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