From patchwork Tue Apr 30 23:47:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13650032 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2ECAC1C0DD6; Tue, 30 Apr 2024 23:48:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714520884; cv=none; b=s/WqerhFmUn5BAOLs1b3IYZtUR188qHvgz+T8kSmWMg6XAUK/R8SCypr8ezDoh9Bum22Ho4k16CQdBHTRNYGckkemkURPH1T2xf7Yh1obqvW5qzv7DPb4+8Wl28EourGFpr0ysMoRmYuFq52nL9b72cT3wo8Z6c9u40Ed14vO4Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714520884; c=relaxed/simple; bh=TbPOTBmS82ynsL8h5jbyPu2ZW+Geh2onSqdzZPRv0KM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=kwZ6FvzAR94qjDMxvS1TPi9+7WgPPNxVVnetmsukzzMbomjzP76e+L206h1F7wUki9ojiyiLOXEolXqlG9bSA/F8Srq7VCUHj8zSrZtYruntaSu9EbxsraKehkridBlfKPAIo1XmdBfzsEM6WpQ+NQfCiOd8QlRpUr7Ds0rNo1M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tSA+FgDi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tSA+FgDi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5121CC2BBFC; Tue, 30 Apr 2024 23:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714520883; bh=TbPOTBmS82ynsL8h5jbyPu2ZW+Geh2onSqdzZPRv0KM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tSA+FgDi+93WO+AFQJliW6fz07aPhOuPF3H2U+c9iHEUTs8IdNonD5Nryx+QQYDyW 3UJni0G5GvaP455JRIG2yJyaN8i1FzTO9j/VLBbbVkx+O0itXnRVZwJ1qjBSeKWQ6g 1lSHCQ7k7q/ITIAcOJe7nfUQiNc7eOUl1n12R7UElCLp/jiadB6ncVGUJG3rqWbx5Z pp+njNfqGUeHYTFeBpVeb/aKhm2ByJUsLSU3noLHUwltQcSBbD+FQzV/nWcTDf5oqb oGGlEI7IUIMo+Hs9iUDdv7eoXJbO06sWhua7lV6mpBtFZcj/KW09ix8BUY+Jjozzb3 iaBTbY7Hq3VOg== From: Puranjay Mohan To: Catalin Marinas , Will Deacon , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Zi Shen Lim , Xu Kuohai , Florent Revest , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Kumar Kartikeya Dwivedi Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v5 1/2] arm64, bpf: add internal-only MOV instruction to resolve per-CPU addrs Date: Tue, 30 Apr 2024 23:47:38 +0000 Message-Id: <20240430234739.79185-2-puranjay@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240430234739.79185-1-puranjay@kernel.org> References: <20240430234739.79185-1-puranjay@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net From: Puranjay Mohan Support an instruction for resolving absolute addresses of per-CPU data from their per-CPU offsets. This instruction is internal-only and users are not allowed to use them directly. They will only be used for internal inlining optimizations for now between BPF verifier and BPF JITs. Since commit 7158627686f0 ("arm64: percpu: implement optimised pcpu access using tpidr_el1"), the per-cpu offset for the CPU is stored in the tpidr_el1/2 register of that CPU. To support this BPF instruction in the ARM64 JIT, the following ARM64 instructions are emitted: mov dst, src // Move src to dst, if src != dst mrs tmp, tpidr_el1/2 // Move per-cpu offset of the current cpu in tmp. add dst, dst, tmp // Add the per cpu offset to the dst. To measure the performance improvement provided by this change, the benchmark in [1] was used: Before: glob-arr-inc : 23.597 ± 0.012M/s arr-inc : 23.173 ± 0.019M/s hash-inc : 12.186 ± 0.028M/s After: glob-arr-inc : 23.819 ± 0.034M/s arr-inc : 23.285 ± 0.017M/s hash-inc : 12.419 ± 0.011M/s [1] https://github.com/anakryiko/linux/commit/8dec900975ef Signed-off-by: Puranjay Mohan --- arch/arm64/include/asm/insn.h | 7 +++++++ arch/arm64/lib/insn.c | 11 +++++++++++ arch/arm64/net/bpf_jit.h | 6 ++++++ arch/arm64/net/bpf_jit_comp.c | 14 ++++++++++++++ 4 files changed, 38 insertions(+) diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index db1aeacd4cd9..8de0e39b29f3 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -135,6 +135,11 @@ enum aarch64_insn_special_register { AARCH64_INSN_SPCLREG_SP_EL2 = 0xF210 }; +enum aarch64_insn_system_register { + AARCH64_INSN_SYSREG_TPIDR_EL1 = 0x4684, + AARCH64_INSN_SYSREG_TPIDR_EL2 = 0x6682, +}; + enum aarch64_insn_variant { AARCH64_INSN_VARIANT_32BIT, AARCH64_INSN_VARIANT_64BIT @@ -686,6 +691,8 @@ u32 aarch64_insn_gen_cas(enum aarch64_insn_register result, } #endif u32 aarch64_insn_gen_dmb(enum aarch64_insn_mb_type type); +u32 aarch64_insn_gen_mrs(enum aarch64_insn_register result, + enum aarch64_insn_system_register sysreg); s32 aarch64_get_branch_offset(u32 insn); u32 aarch64_set_branch_offset(u32 insn, s32 offset); diff --git a/arch/arm64/lib/insn.c b/arch/arm64/lib/insn.c index a635ab83fee3..b008a9b46a7f 100644 --- a/arch/arm64/lib/insn.c +++ b/arch/arm64/lib/insn.c @@ -1515,3 +1515,14 @@ u32 aarch64_insn_gen_dmb(enum aarch64_insn_mb_type type) return insn; } + +u32 aarch64_insn_gen_mrs(enum aarch64_insn_register result, + enum aarch64_insn_system_register sysreg) +{ + u32 insn = aarch64_insn_get_mrs_value(); + + insn &= ~GENMASK(19, 0); + insn |= sysreg << 5; + return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, + insn, result); +} diff --git a/arch/arm64/net/bpf_jit.h b/arch/arm64/net/bpf_jit.h index 23b1b34db088..b627ef7188c7 100644 --- a/arch/arm64/net/bpf_jit.h +++ b/arch/arm64/net/bpf_jit.h @@ -297,4 +297,10 @@ #define A64_ADR(Rd, offset) \ aarch64_insn_gen_adr(0, offset, Rd, AARCH64_INSN_ADR_TYPE_ADR) +/* MRS */ +#define A64_MRS_TPIDR_EL1(Rt) \ + aarch64_insn_gen_mrs(Rt, AARCH64_INSN_SYSREG_TPIDR_EL1) +#define A64_MRS_TPIDR_EL2(Rt) \ + aarch64_insn_gen_mrs(Rt, AARCH64_INSN_SYSREG_TPIDR_EL2) + #endif /* _BPF_JIT_H */ diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 76b91f36c729..ed8f9716d9d5 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -877,6 +877,15 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, emit(A64_ORR(1, tmp, dst, tmp), ctx); emit(A64_MOV(1, dst, tmp), ctx); break; + } else if (insn_is_mov_percpu_addr(insn)) { + if (dst != src) + emit(A64_MOV(1, dst, src), ctx); + if (cpus_have_cap(ARM64_HAS_VIRT_HOST_EXTN)) + emit(A64_MRS_TPIDR_EL2(tmp), ctx); + else + emit(A64_MRS_TPIDR_EL1(tmp), ctx); + emit(A64_ADD(1, dst, dst, tmp), ctx); + break; } switch (insn->off) { case 0: @@ -2527,6 +2536,11 @@ bool bpf_jit_supports_arena(void) return true; } +bool bpf_jit_supports_percpu_insn(void) +{ + return true; +} + void bpf_jit_free(struct bpf_prog *prog) { if (prog->jited) { From patchwork Tue Apr 30 23:47:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13650033 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B2961C2327; 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dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OW15PHNu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF3EFC4AF1B; Tue, 30 Apr 2024 23:48:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1714520887; bh=CJftWXVNhPrzRJ8tO7vV2W8FE8qYON08xPmi6fVAAdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OW15PHNubEu4xCwocIM+Qm5Bb70vBbuA9qr4coQ00C6pV9cKp8NBbJOiSJDcEnlx+ /itoRLDRYZPh2QCIk+9VEZ0O3IGWVfrLoUCq4NJ4avE4j3HztGFDAzcAvWEydVV3lE zpzf3hCSrPuEpZq7wXe2KyGZ8HOXO0Y1Dpru4FOXF3pZ5+uJqQRiLDM27DNO3WGNBl aZcROQfzDsb7UjCZuvlX4uJA8ofTIOc0ZFITL5bsa1Q9r8kXgv4n76a/qnTGvdsavj RNp4CbyoAyFtmbu1iDGVdoFJrmz03MNMnS7RlExPXRpOSbM7ABgGQSSclqkVQTb3+Q bfmnrQPYBgc4Q== From: Puranjay Mohan To: Catalin Marinas , Will Deacon , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Zi Shen Lim , Xu Kuohai , Florent Revest , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Kumar Kartikeya Dwivedi Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v5 2/2] bpf, arm64: inline bpf_get_smp_processor_id() helper Date: Tue, 30 Apr 2024 23:47:39 +0000 Message-Id: <20240430234739.79185-3-puranjay@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240430234739.79185-1-puranjay@kernel.org> References: <20240430234739.79185-1-puranjay@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net Inline calls to bpf_get_smp_processor_id() helper in the JIT by emitting a read from struct thread_info. The SP_EL0 system register holds the pointer to the task_struct and thread_info is the first member of this struct. We can read the cpu number from the thread_info. Here is how the ARM64 JITed assembly changes after this commit: ARM64 JIT =========== BEFORE AFTER -------- ------- int cpu = bpf_get_smp_processor_id(); int cpu = bpf_get_smp_processor_id(); mov x10, #0xfffffffffffff4d0 mrs x10, sp_el0 movk x10, #0x802b, lsl #16 ldr w7, [x10, #24] movk x10, #0x8000, lsl #32 blr x10 add x7, x0, #0x0 Performance improvement using benchmark[1] ./benchs/run_bench_trigger.sh glob-arr-inc arr-inc hash-inc +---------------+-------------------+-------------------+--------------+ | Name | Before | After | % change | |---------------+-------------------+-------------------+--------------| | glob-arr-inc | 23.380 ± 1.675M/s | 25.893 ± 0.026M/s | + 10.74% | | arr-inc | 23.928 ± 0.034M/s | 25.213 ± 0.063M/s | + 5.37% | | hash-inc | 12.352 ± 0.005M/s | 12.609 ± 0.013M/s | + 2.08% | +---------------+-------------------+-------------------+--------------+ [1] https://github.com/anakryiko/linux/commit/8dec900975ef Signed-off-by: Puranjay Mohan Acked-by: Andrii Nakryiko --- arch/arm64/include/asm/insn.h | 1 + arch/arm64/net/bpf_jit.h | 2 ++ arch/arm64/net/bpf_jit_comp.c | 23 +++++++++++++++++++++++ 3 files changed, 26 insertions(+) diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 8de0e39b29f3..8c0a36f72d6f 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -138,6 +138,7 @@ enum aarch64_insn_special_register { enum aarch64_insn_system_register { AARCH64_INSN_SYSREG_TPIDR_EL1 = 0x4684, AARCH64_INSN_SYSREG_TPIDR_EL2 = 0x6682, + AARCH64_INSN_SYSREG_SP_EL0 = 0x4208, }; enum aarch64_insn_variant { diff --git a/arch/arm64/net/bpf_jit.h b/arch/arm64/net/bpf_jit.h index b627ef7188c7..b22ab2f97a30 100644 --- a/arch/arm64/net/bpf_jit.h +++ b/arch/arm64/net/bpf_jit.h @@ -302,5 +302,7 @@ aarch64_insn_gen_mrs(Rt, AARCH64_INSN_SYSREG_TPIDR_EL1) #define A64_MRS_TPIDR_EL2(Rt) \ aarch64_insn_gen_mrs(Rt, AARCH64_INSN_SYSREG_TPIDR_EL2) +#define A64_MRS_SP_EL0(Rt) \ + aarch64_insn_gen_mrs(Rt, AARCH64_INSN_SYSREG_SP_EL0) #endif /* _BPF_JIT_H */ diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index ed8f9716d9d5..8084f3e61e0b 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -1215,6 +1215,19 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, const u8 r0 = bpf2a64[BPF_REG_0]; bool func_addr_fixed; u64 func_addr; + u32 cpu_offset = offsetof(struct thread_info, cpu); + + /* Implement helper call to bpf_get_smp_processor_id() inline */ + if (insn->src_reg == 0 && insn->imm == BPF_FUNC_get_smp_processor_id) { + emit(A64_MRS_SP_EL0(tmp), ctx); + if (is_lsi_offset(cpu_offset, 2)) { + emit(A64_LDR32I(r0, tmp, cpu_offset), ctx); + } else { + emit_a64_mov_i(1, tmp2, cpu_offset, ctx); + emit(A64_LDR32(r0, tmp, tmp2), ctx); + } + break; + } ret = bpf_jit_get_func_addr(ctx->prog, insn, extra_pass, &func_addr, &func_addr_fixed); @@ -2541,6 +2554,16 @@ bool bpf_jit_supports_percpu_insn(void) return true; } +bool bpf_jit_inlines_helper_call(s32 imm) +{ + switch (imm) { + case BPF_FUNC_get_smp_processor_id: + return true; + } + + return false; +} + void bpf_jit_free(struct bpf_prog *prog) { if (prog->jited) {