From patchwork Wed Nov 1 00:18:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 13442359 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id E4DA4C4167D for ; Wed, 1 Nov 2023 00:19:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References:Message-Id :MIME-Version:Subject:Date:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8bOAz/iXgCYhhXdIulHBE7GTxkL/A4CGrJAdvixBVRM=; b=vpFI49PSkna5au PQM4FX/3mPGAYAEwhG4NATijfJMluZB2dGYlIBWenz/hDwJJa9WJfNUGL3ixWxp6mRgFL3NDgmVJs tcNJmoW/F9WvTevUy0FgG5gc2HdhSZCsJFB/fbQ6vM2PDlZCjmSdxf1pCz50n4j8Ydfqy5/l/Pr6X VvvfUQ+JBT7WDJOejpASfENqRz3dgj0sZBdjBSAl0J15R6yp7/5abU3xqUHzSJMClPo5WhM/NXXPX U+qHD1tB/MYv39flmDOwIRS9WAdfvO92dWbx9gLVUHLipBvt4pNLkgbj6WRjD1lKP943FSZQum68G Qp0ZAEytJ8wFXXa8uKsw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qxyxA-006NXv-1F; Wed, 01 Nov 2023 00:19:24 +0000 Received: from mail-oi1-x229.google.com ([2607:f8b0:4864:20::229]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qxyx3-006NVC-39 for linux-riscv@lists.infradead.org; Wed, 01 Nov 2023 00:19:19 +0000 Received: by mail-oi1-x229.google.com with SMTP id 5614622812f47-3b2b1af09c5so3209897b6e.0 for ; Tue, 31 Oct 2023 17:19:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1698797954; x=1699402754; darn=lists.infradead.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=/13350laV5cH/gW7bwr46BLHMJ2uc/+UPn+OeXEdCHA=; b=AI4lkQTtHXpD3tZXul2qn0u2RYjpwuakaMcKUN4np7GRgRL790iO9vti/rUN+gzh7S v8jozfdr3Kx68MFzre9sUbrXQNVnFTCwQdnOT6ueVgN0fjLNbyxxSOkMVp5Iy/OK01xk YYvzaLRcWfQGmsYu3jBbXpuiJqtnjTm3Qj4etI4h9eIWV8Bae178HhTZ1gykTxHUqRh+ Shc5SbHWgZVWbzgh9Bk7SRpkRboSfwt+v10wuqm/a8ZZeZzc3+RRYPXBvlyLBIRBPawG mFj67q4CFf0CSuvRxBIRqQjjHdNTqKBZvt6pM1gOhuXgf6o5c7WbatQEGI47B2wtDTMi pmEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698797954; x=1699402754; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/13350laV5cH/gW7bwr46BLHMJ2uc/+UPn+OeXEdCHA=; b=kugnSp9Dzvpx0QFLo7lQVlJsfOMgZqrp194wQOUgiNLkvjWbXIODuRa/wm7k6vr7ih Gg6/IiKqRVcvOJk9uhGHh3mNLrtyl7CoUbp3KbjjWyZ9DqpP+FFhNzTXRr83k90p/5Bq pqefa2PlVk4rmO/j8UgJ06U7u2n+l1d6eg+Tvy3hFTtYUTnif9xgm15wmq9TibViyW11 Nkuiqn/XHBmms5U31V4jhkTvDYrgVhmoMrvWOzulNUMjxwJWFqz+n3pfGnvTIRU9Ouyl vZd+6JeExtt3GFnZzoDUToMrAFLpfaxXtlzuG+CofPzrip6QniBJicYL0NxwQGnJ0deM oPhA== X-Gm-Message-State: AOJu0YwajdHXP4YawsOchL/eQbxkrVBY5q1l5dOWrK9BDMliIwgxQT7c AR/lFzRvjAvRLuAPdMUgX928VLn0FXj7VqlP8DE= X-Google-Smtp-Source: AGHT+IF9urQDZ+KzKtfxqZ98bDFGvykX5VrXyLdKok+Olt9zxl/2dzxgOHIf+UVXvbkP6NHUNWGN0g== X-Received: by 2002:a05:6808:f8e:b0:3ae:2850:b481 with SMTP id o14-20020a0568080f8e00b003ae2850b481mr14863594oiw.17.1698797954260; Tue, 31 Oct 2023 17:19:14 -0700 (PDT) Received: from charlie.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id n21-20020aca2415000000b003af638fd8e4sm65309oic.55.2023.10.31.17.19.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 31 Oct 2023 17:19:13 -0700 (PDT) From: Charlie Jenkins Date: Tue, 31 Oct 2023 17:18:54 -0700 Subject: [PATCH v9 4/5] riscv: Add checksum library MIME-Version: 1.0 Message-Id: <20231031-optimize_checksum-v9-4-ea018e69b229@rivosinc.com> References: <20231031-optimize_checksum-v9-0-ea018e69b229@rivosinc.com> In-Reply-To: <20231031-optimize_checksum-v9-0-ea018e69b229@rivosinc.com> To: Charlie Jenkins , Palmer Dabbelt , Conor Dooley , Samuel Holland , David Laight , Xiao Wang , Evan Green , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Cc: Paul Walmsley , Albert Ou , Arnd Bergmann , Conor Dooley X-Mailer: b4 0.12.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231031_171918_017189_80D38BE0 X-CRM114-Status: GOOD ( 25.56 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Provide a 32 and 64 bit version of do_csum. When compiled for 32-bit will load from the buffer in groups of 32 bits, and when compiled for 64-bit will load in groups of 64 bits. Signed-off-by: Charlie Jenkins Acked-by: Conor Dooley --- arch/riscv/include/asm/checksum.h | 11 ++ arch/riscv/lib/Makefile | 1 + arch/riscv/lib/csum.c | 326 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 338 insertions(+) diff --git a/arch/riscv/include/asm/checksum.h b/arch/riscv/include/asm/checksum.h index 3d77cac338fe..f8f8e437a88a 100644 --- a/arch/riscv/include/asm/checksum.h +++ b/arch/riscv/include/asm/checksum.h @@ -12,6 +12,17 @@ #define ip_fast_csum ip_fast_csum +extern unsigned int do_csum(const unsigned char *buff, int len); +#define do_csum do_csum + +/* Default version is sufficient for 32 bit */ +#ifndef CONFIG_32BIT +#define _HAVE_ARCH_IPV6_CSUM +__sum16 csum_ipv6_magic(const struct in6_addr *saddr, + const struct in6_addr *daddr, + __u32 len, __u8 proto, __wsum sum); +#endif + /* Define riscv versions of functions before importing asm-generic/checksum.h */ #include diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index 26cb2502ecf8..2aa1a4ad361f 100644 --- a/arch/riscv/lib/Makefile +++ b/arch/riscv/lib/Makefile @@ -6,6 +6,7 @@ lib-y += memmove.o lib-y += strcmp.o lib-y += strlen.o lib-y += strncmp.o +lib-y += csum.o lib-$(CONFIG_MMU) += uaccess.o lib-$(CONFIG_64BIT) += tishift.o lib-$(CONFIG_RISCV_ISA_ZICBOZ) += clear_page.o diff --git a/arch/riscv/lib/csum.c b/arch/riscv/lib/csum.c new file mode 100644 index 000000000000..3221d4520bbb --- /dev/null +++ b/arch/riscv/lib/csum.c @@ -0,0 +1,326 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Checksum library + * + * Influenced by arch/arm64/lib/csum.c + * Copyright (C) 2023 Rivos Inc. + */ +#include +#include +#include +#include +#include +#include + +#include + +/* Default version is sufficient for 32 bit */ +#ifndef CONFIG_32BIT +__sum16 csum_ipv6_magic(const struct in6_addr *saddr, + const struct in6_addr *daddr, + __u32 len, __u8 proto, __wsum csum) +{ + unsigned int ulen, uproto; + unsigned long sum = csum; + + sum += saddr->s6_addr32[0]; + sum += saddr->s6_addr32[1]; + sum += saddr->s6_addr32[2]; + sum += saddr->s6_addr32[3]; + + sum += daddr->s6_addr32[0]; + sum += daddr->s6_addr32[1]; + sum += daddr->s6_addr32[2]; + sum += daddr->s6_addr32[3]; + + ulen = htonl((unsigned int)len); + sum += ulen; + + uproto = htonl(proto); + sum += uproto; + + /* + * Zbb support saves 4 instructions, so not worth checking without + * alternatives if supported + */ + if (IS_ENABLED(CONFIG_RISCV_ISA_ZBB) && + IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { + unsigned long fold_temp; + + /* + * Zbb is likely available when the kernel is compiled with Zbb + * support, so nop when Zbb is available and jump when Zbb is + * not available. + */ + asm_volatile_goto(ALTERNATIVE("j %l[no_zbb]", "nop", 0, + RISCV_ISA_EXT_ZBB, 1) + : + : + : + : no_zbb); + asm(".option push \n\ + .option arch,+zbb \n\ + rori %[fold_temp], %[sum], 32 \n\ + add %[sum], %[fold_temp], %[sum] \n\ + srli %[sum], %[sum], 32 \n\ + not %[fold_temp], %[sum] \n\ + roriw %[sum], %[sum], 16 \n\ + subw %[sum], %[fold_temp], %[sum] \n\ + .option pop" + : [sum] "+r" (sum), [fold_temp] "=&r" (fold_temp)); + return (__force __sum16)(sum >> 16); + } +no_zbb: + sum += ror64(sum, 32); + sum >>= 32; + return csum_fold((__force __wsum)sum); +} +EXPORT_SYMBOL(csum_ipv6_magic); +#endif /* !CONFIG_32BIT */ + +#ifdef CONFIG_32BIT +#define OFFSET_MASK 3 +#elif CONFIG_64BIT +#define OFFSET_MASK 7 +#endif + +static inline __no_sanitize_address unsigned long +do_csum_common(const unsigned long *ptr, const unsigned char *buff, int len, + unsigned long data) +{ + unsigned int shift; + const unsigned long *end; + unsigned long csum = 0, carry = 0; + + end = (const unsigned long *)(buff + len); + + /* + * Do 32-bit reads on RV32 and 64-bit reads otherwise. This should be + * faster than doing 32-bit reads on architectures that support larger + * reads. + */ + while (ptr < end) { + csum += data; + carry += csum < data; + len -= sizeof(long); + data = *(ptr++); + } + + /* + * Perform alignment (and over-read) bytes on the tail if any bytes + * leftover. + */ + shift = ((long)ptr - (long)end) * 8; +#ifdef __LITTLE_ENDIAN + data = (data << shift) >> shift; +#else + data = (data >> shift) << shift; +#endif + csum += data; + carry += csum < data; + csum += carry; + csum += csum < carry; + + return csum; +} + +/* + * Algorithm accounts for buff being misaligned. + * If buff is not aligned, will over-read bytes but not use the bytes that it + * shouldn't. The same thing will occur on the tail-end of the read. + */ +static inline __no_sanitize_address unsigned int +do_csum_with_alignment(const unsigned char *buff, int len) +{ + unsigned int offset, shift; + unsigned long csum, data; + const unsigned long *ptr; + + /* + * Align address to closest word (double word on rv64) that comes before + * buff. This should always be in the same page and cache line. + * Directly call KASAN with the alignment we will be using. + */ + offset = (unsigned long)buff & OFFSET_MASK; + kasan_check_read(buff, len); + ptr = (const unsigned long *)(buff - offset); + + /* + * Clear the most significant bytes that were over-read if buff was not + * aligned. + */ + shift = offset * 8; + data = *(ptr++); +#ifdef __LITTLE_ENDIAN + data = (data >> shift) << shift; +#else + data = (data << shift) >> shift; +#endif + + csum = do_csum_common(ptr, buff, len, data); + + /* + * Zbb support saves 6 instructions, so not worth checking without + * alternatives if supported + */ + if (IS_ENABLED(CONFIG_RISCV_ISA_ZBB) && + IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { + unsigned long fold_temp; + + /* + * Zbb is likely available when the kernel is compiled with Zbb + * support, so nop when Zbb is available and jump when Zbb is + * not available. + */ + asm_volatile_goto(ALTERNATIVE("j %l[no_zbb]", "nop", 0, + RISCV_ISA_EXT_ZBB, 1) + : + : + : + : no_zbb); + +#ifdef CONFIG_32BIT + asm_volatile_goto(".option push \n\ + .option arch,+zbb \n\ + rori %[fold_temp], %[csum], 16 \n\ + andi %[offset], %[offset], 1 \n\ + add %[csum], %[fold_temp], %[csum] \n\ + beq %[offset], zero, %l[end] \n\ + rev8 %[csum], %[csum] \n\ + .option pop" + : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp) + : [offset] "r" (offset) + : + : end); + + return (unsigned short)csum; +#else /* !CONFIG_32BIT */ + asm_volatile_goto(".option push \n\ + .option arch,+zbb \n\ + rori %[fold_temp], %[csum], 32 \n\ + add %[csum], %[fold_temp], %[csum] \n\ + srli %[csum], %[csum], 32 \n\ + roriw %[fold_temp], %[csum], 16 \n\ + addw %[csum], %[fold_temp], %[csum] \n\ + andi %[offset], %[offset], 1 \n\ + beq %[offset], zero, %l[end] \n\ + rev8 %[csum], %[csum] \n\ + .option pop" + : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp) + : [offset] "r" (offset) + : + : end); + + return (csum << 16) >> 48; +#endif /* !CONFIG_32BIT */ +end: + return csum >> 16; + } +no_zbb: +#ifndef CONFIG_32BIT + csum += ror64(csum, 32); + csum >>= 32; +#endif + csum = (u32)csum + ror32((u32)csum, 16); + if (offset & 1) + return (u16)swab32(csum); + return csum >> 16; +} + +/* + * Does not perform alignment, should only be used if machine has fast + * misaligned accesses, or when buff is known to be aligned. + */ +static inline unsigned int do_csum_no_alignment(const unsigned char *buff, int len) +{ + unsigned long csum, data; + const unsigned long *ptr; + + ptr = (const unsigned long *)(buff); + + data = *(ptr++); + + csum = do_csum_common(ptr, buff, len, data); + + /* + * Zbb support saves 6 instructions, so not worth checking without + * alternatives if supported + */ + if (IS_ENABLED(CONFIG_RISCV_ISA_ZBB) && + IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { + unsigned long fold_temp; + + /* + * Zbb is likely available when the kernel is compiled with Zbb + * support, so nop when Zbb is available and jump when Zbb is + * not available. + */ + asm_volatile_goto(ALTERNATIVE("j %l[no_zbb]", "nop", 0, + RISCV_ISA_EXT_ZBB, 1) + : + : + : + : no_zbb); + +#ifdef CONFIG_32BIT + asm (".option push \n\ + .option arch,+zbb \n\ + rori %[fold_temp], %[csum], 16 \n\ + add %[csum], %[fold_temp], %[csum] \n\ + .option pop" + : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp) + : + : ); + +#else /* !CONFIG_32BIT */ + asm (".option push \n\ + .option arch,+zbb \n\ + rori %[fold_temp], %[csum], 32 \n\ + add %[csum], %[fold_temp], %[csum] \n\ + srli %[csum], %[csum], 32 \n\ + roriw %[fold_temp], %[csum], 16 \n\ + addw %[csum], %[fold_temp], %[csum] \n\ + .option pop" + : [csum] "+r" (csum), [fold_temp] "=&r" (fold_temp) + : + : ); +#endif /* !CONFIG_32BIT */ + return csum >> 16; + } +no_zbb: +#ifndef CONFIG_32BIT + csum += ror64(csum, 32); + csum >>= 32; +#endif + csum = (u32)csum + ror32((u32)csum, 16); + return csum >> 16; +} + +/* + * Perform a checksum on an arbitrary memory address. + * Will do a light-weight address alignment if buff is misaligned, unless + * cpu supports fast misaligned accesses. + */ +unsigned int do_csum(const unsigned char *buff, int len) +{ + if (unlikely(len <= 0)) + return 0; + + /* + * Significant performance gains can be seen by not doing alignment + * on machines with fast misaligned accesses. + * + * There is some duplicate code between the "with_alignment" and + * "no_alignment" implmentations, but the overlap is too awkward to be + * able to fit in one function without introducing multiple static + * branches. The largest chunk of overlap was delegated into the + * do_csum_common function. + */ + if (static_branch_likely(&fast_misaligned_access_speed_key)) + return do_csum_no_alignment(buff, len); + + if (((unsigned long)buff & OFFSET_MASK) == 0) + return do_csum_no_alignment(buff, len); + + return do_csum_with_alignment(buff, len); +}