From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE357C47257 for ; Thu, 7 May 2020 01:05:41 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B2F1C20747 for ; Thu, 7 May 2020 01:05:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="k6POVQYP"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=cs.washington.edu header.i=@cs.washington.edu header.b="MzUALuxS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B2F1C20747 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cs.washington.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=79alCKKeQ8jzZsoM/jsjGu5AGGUpQRw4Vt3EwsxGWCs=; b=k6POVQYP1zJSISH1vbe3ChlFKx IphTWrQGlUKp1a65Fn1w+WLLbGfLmEi0151SDoQ4zFzAUJumh7RVGN+8M459WtIY0lNFwc+8qdfs3 HkeGG3vaeejxf8pNVTY9hI8ezu74roKHx0wgnDakIadJZOELylJhsXiXxSeVNdcW8+i2nDz4N7PJD crzB+eZ3Bi9caE9tm31FwIpd8kwbmqF898z7oEGGbEYHm9S6jURlPvY7DBVlJ7L9As4JldCOlqDSC vJ+G+U1pWnDJ5z0r+bEyQ8RV9KGzteI1KXIZaBM4n3S//3hrjrgjJs9k56Q6ing+TivJ1P7avmata 8gLdw3gQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWUyr-0001Z7-0P; Thu, 07 May 2020 01:05:41 +0000 Received: from mail-pl1-x641.google.com ([2607:f8b0:4864:20::641]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWUyS-00017O-14 for linux-arm-kernel@lists.infradead.org; Thu, 07 May 2020 01:05:17 +0000 Received: by mail-pl1-x641.google.com with SMTP id b6so1354664plz.13 for ; Wed, 06 May 2020 18:05:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cs.washington.edu; s=goo201206; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=tkBqx/wfZEl+tIcjb11yTPyE7+YEVimiwOlUfbRN11I=; b=MzUALuxSHI8uGN17akBqWhBWPav29bHPkcPrh9x/umRUluVK6xacxj/WYMuj4bFTeU oJ1fRh/BHW0t2Jeon/fnKRHc/cQW2ER4sIw3Y4MGWVZ7ek3t93U/nViHmcIX0u7owbrf 3jCE0UDtYtJ1nGos034cmOKd/G9S9ntSCYXYw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=tkBqx/wfZEl+tIcjb11yTPyE7+YEVimiwOlUfbRN11I=; b=f/gC0Y4wj5S1hUqFx2F02noy6hNVHBtCcIiGIizPyMcbkvLpxGmeroQeAnuGwW9lzh hXapNrJBq//KB1aO2ElQ5D5QDIAXKGo/s5pcxjDe2yl6lPLJY4Nyq2Fu06I1gV4e4UA6 JCm3z1z22nLjtyJNcPe0ohAvGzgPR1zi+2rcQe0xWg7CL+YDXgJhXgGhOmtFPoPkMvAO bmCC4IS2Ao/iB9YHwaWwJClG4H7jaIMSitnC9rbtWHOrwDlbaJv+QBYtn0iMVGcI+ekG Top9hLg+T12DUxzQjMxiw9wv34oWQBcFxgHGoO1hNnogdsTGZdk6gMtJ3eBD5p9gneOy 4Ctg== X-Gm-Message-State: AGi0PuaHx0/id3Gj3bVx/9Tp8Vez+Fq4At5iRAXUN8t4TkZINld/snbl Kc6Nd3uGFP0v3v6/E6kj1H61Ug== X-Google-Smtp-Source: APiQypIW2OFc7mkJ2PHrB5uAFjiSFWcgygWE+H6N56zj0yYwwbVdI6tvI0GuaDtoalZ3e5F3kIqqzA== X-Received: by 2002:a17:90a:77c6:: with SMTP id e6mr13041525pjs.84.1588813515058; Wed, 06 May 2020 18:05:15 -0700 (PDT) Received: from localhost.localdomain (c-73-53-94-119.hsd1.wa.comcast.net. [73.53.94.119]) by smtp.gmail.com with ESMTPSA id ev5sm6165250pjb.1.2020.05.06.18.05.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 May 2020 18:05:14 -0700 (PDT) From: Luke Nelson X-Google-Original-From: Luke Nelson To: bpf@vger.kernel.org Subject: [RFC PATCH bpf-next 2/3] bpf, arm64: Optimize AND, OR, XOR, JSET BPF_K using arm64 logical immediates Date: Wed, 6 May 2020 18:05:02 -0700 Message-Id: <20200507010504.26352-3-luke.r.nels@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200507010504.26352-1-luke.r.nels@gmail.com> References: <20200507010504.26352-1-luke.r.nels@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200506_180516_123469_DA3A8DFF X-CRM114-Status: GOOD ( 16.04 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Song Liu , Catalin Marinas , Alexei Starovoitov , Will Deacon , Daniel Borkmann , Marc Zyngier , John Fastabend , clang-built-linux@googlegroups.com, Zi Shen Lim , Yonghong Song , Andrii Nakryiko , Xi Wang , Luke Nelson , Alexios Zavras , KP Singh , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Enrico Weigelt , Martin KaFai Lau , Christoffer Dall MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org The current code for BPF_{AND,OR,XOR,JSET} BPF_K loads the immediate to a temporary register before use. This patch changes the code to avoid using a temporary register when the BPF immediate is encodable using an arm64 logical immediate instruction. If the encoding fails (due to the immediate not being encodable), it falls back to using a temporary register. Example of generated code for BPF_ALU32_IMM(BPF_AND, R0, 0x80000001): without optimization: 24: mov w10, #0x8000ffff 28: movk w10, #0x1 2c: and w7, w7, w10 with optimization: 24: and w7, w7, #0x80000001 Since the encoding process is quite complex, the JIT reuses existing functionality in arch/arm64/kernel/insn.c for encoding logical immediates rather than duplicate it in the JIT. Co-developed-by: Xi Wang Signed-off-by: Xi Wang Signed-off-by: Luke Nelson --- arch/arm64/net/bpf_jit.h | 14 +++++++++++++ arch/arm64/net/bpf_jit_comp.c | 37 +++++++++++++++++++++++++++-------- 2 files changed, 43 insertions(+), 8 deletions(-) diff --git a/arch/arm64/net/bpf_jit.h b/arch/arm64/net/bpf_jit.h index eb73f9f72c46..f36a779949e6 100644 --- a/arch/arm64/net/bpf_jit.h +++ b/arch/arm64/net/bpf_jit.h @@ -189,4 +189,18 @@ /* Rn & Rm; set condition flags */ #define A64_TST(sf, Rn, Rm) A64_ANDS(sf, A64_ZR, Rn, Rm) +/* Logical (immediate) */ +#define A64_LOGIC_IMM(sf, Rd, Rn, imm, type) ({ \ + u64 imm64 = (sf) ? (u64)imm : (u64)(u32)imm; \ + aarch64_insn_gen_logical_immediate(AARCH64_INSN_LOGIC_##type, \ + A64_VARIANT(sf), Rn, Rd, imm64); \ +}) +/* Rd = Rn OP imm */ +#define A64_AND_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, AND) +#define A64_ORR_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, ORR) +#define A64_EOR_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, EOR) +#define A64_ANDS_I(sf, Rd, Rn, imm) A64_LOGIC_IMM(sf, Rd, Rn, imm, AND_SETFLAGS) +/* Rn & imm; set condition flags */ +#define A64_TST_I(sf, Rn, imm) A64_ANDS_I(sf, A64_ZR, Rn, imm) + #endif /* _BPF_JIT_H */ diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index cdc79de0c794..083e5d8a5e2c 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -356,6 +356,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, const bool isdw = BPF_SIZE(code) == BPF_DW; u8 jmp_cond, reg; s32 jmp_offset; + u32 a64_insn; #define check_imm(bits, imm) do { \ if ((((imm) > 0) && ((imm) >> (bits))) || \ @@ -488,18 +489,33 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, break; case BPF_ALU | BPF_AND | BPF_K: case BPF_ALU64 | BPF_AND | BPF_K: - emit_a64_mov_i(is64, tmp, imm, ctx); - emit(A64_AND(is64, dst, dst, tmp), ctx); + a64_insn = A64_AND_I(is64, dst, dst, imm); + if (a64_insn != AARCH64_BREAK_FAULT) { + emit(a64_insn, ctx); + } else { + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_AND(is64, dst, dst, tmp), ctx); + } break; case BPF_ALU | BPF_OR | BPF_K: case BPF_ALU64 | BPF_OR | BPF_K: - emit_a64_mov_i(is64, tmp, imm, ctx); - emit(A64_ORR(is64, dst, dst, tmp), ctx); + a64_insn = A64_ORR_I(is64, dst, dst, imm); + if (a64_insn != AARCH64_BREAK_FAULT) { + emit(a64_insn, ctx); + } else { + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_ORR(is64, dst, dst, tmp), ctx); + } break; case BPF_ALU | BPF_XOR | BPF_K: case BPF_ALU64 | BPF_XOR | BPF_K: - emit_a64_mov_i(is64, tmp, imm, ctx); - emit(A64_EOR(is64, dst, dst, tmp), ctx); + a64_insn = A64_EOR_I(is64, dst, dst, imm); + if (a64_insn != AARCH64_BREAK_FAULT) { + emit(a64_insn, ctx); + } else { + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_EOR(is64, dst, dst, tmp), ctx); + } break; case BPF_ALU | BPF_MUL | BPF_K: case BPF_ALU64 | BPF_MUL | BPF_K: @@ -628,8 +644,13 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, goto emit_cond_jmp; case BPF_JMP | BPF_JSET | BPF_K: case BPF_JMP32 | BPF_JSET | BPF_K: - emit_a64_mov_i(is64, tmp, imm, ctx); - emit(A64_TST(is64, dst, tmp), ctx); + a64_insn = A64_TST_I(is64, dst, imm); + if (a64_insn != AARCH64_BREAK_FAULT) { + emit(a64_insn, ctx); + } else { + emit_a64_mov_i(is64, tmp, imm, ctx); + emit(A64_TST(is64, dst, tmp), ctx); + } goto emit_cond_jmp; /* function call */ case BPF_JMP | BPF_CALL: -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel