From patchwork Tue Feb 1 19:01:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 12732165 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E854FC433FE for ; Tue, 1 Feb 2022 19:01:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237340AbiBATBi (ORCPT ); Tue, 1 Feb 2022 14:01:38 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:40942 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242236AbiBATBh (ORCPT ); Tue, 1 Feb 2022 14:01:37 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4A5C5B82F74; Tue, 1 Feb 2022 19:01:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEDE6C340ED; Tue, 1 Feb 2022 19:01:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643742095; bh=cwL3Yb4NVpj+ob2OmpLnPEK7lctKEkyo+6WsvIqLm5s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hlE6jUFXela4nAgKZuQVJve3sMcSgy6npH2+MSEYxrOtxTjEW+utcSCOEcrnnzq/r 7KUUUNWSNqaPMF9qFCmtay/jZINrNbLQtsaqqx7/r13h1nl1sA0JnDxos3WLfs99bX v8/Wsse/9U+hsLTfUZQt0WVZSdFzIV6AdXHMc6Y2HkyjsAmf9+mDSz8KMs+MBYYCB7 Kuo768495Rp1NO1l39QSAJv8MAQwvoAXUCfZHqNxs+rePcRDACMpE6MPF2wAxX9aZF mxA2iW+a/jOuzJOMbXdVgcoNRuIjxWrxYjzh4u51RDkAgJiNlebfXULalhS/Ip7Ehe aWKyYT7duIX7g== From: Keith Busch To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Cc: axboe@kernel.dk, hch@lst.de, martin.petersen@oracle.com, colyli@suse.de, Keith Busch , Eric Biggers Subject: [PATCHv2 3/7] lib: add rocksoft model crc64 Date: Tue, 1 Feb 2022 11:01:24 -0800 Message-Id: <20220201190128.3075065-4-kbusch@kernel.org> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20220201190128.3075065-1-kbusch@kernel.org> References: <20220201190128.3075065-1-kbusch@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The NVM Express specification extended data integrity fields to 64 bits using the Rocksoft^TM parameters. Add the poly to the crc64 table generation, and provide a library routine implementing the algorithm. The Rocksoft 64-bit CRC model parameters are as follows: Poly: 0xAD93D23594C93659 Initial value: 0xFFFFFFFFFFFFFFFF Reflected Input: True Reflected Output: True Xor Final: 0xFFFFFFFFFFFFFFFF Since this model used reflected bits, the implementation generates the reflected table so the result is ordered consistently. Cc: Eric Biggers Signed-off-by: Keith Busch Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke --- v1->v2: Generate a reflected table for the polynomial so that the inputs and outputs don't need to be reflected during calculating the CRC include/linux/crc64.h | 2 ++ lib/crc64.c | 26 ++++++++++++++++++++++ lib/gen_crc64table.c | 51 +++++++++++++++++++++++++++++++++---------- 3 files changed, 68 insertions(+), 11 deletions(-) diff --git a/include/linux/crc64.h b/include/linux/crc64.h index c756e65a1b58..9f2f20216503 100644 --- a/include/linux/crc64.h +++ b/include/linux/crc64.h @@ -8,4 +8,6 @@ #include u64 __pure crc64_be(u64 crc, const void *p, size_t len); +u64 __pure crc64_rocksoft(u64 crc, const void *p, size_t len); + #endif /* _LINUX_CRC64_H */ diff --git a/lib/crc64.c b/lib/crc64.c index 9f852a89ee2a..e223e72be44d 100644 --- a/lib/crc64.c +++ b/lib/crc64.c @@ -22,6 +22,13 @@ * x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 + * x^7 + x^4 + x + 1 * + * crc64rocksoft[256] table is from the Rocksoft specification polynomial + * defined as, + * + * x^64 + x^63 + x^61 + x^59 + x^58 + x^56 + x^55 + x^52 + x^49 + x^48 + x^47 + + * x^46 + x^44 + x^41 + x^37 + x^36 + x^34 + x^32 + x^31 + x^28 + x^26 + x^23 + + * x^22 + x^19 + x^16 + x^13 + x^12 + x^10 + x^9 + x^6 + x^4 + x^3 + 1 + * * Copyright 2018 SUSE Linux. * Author: Coly Li */ @@ -55,3 +62,22 @@ u64 __pure crc64_be(u64 crc, const void *p, size_t len) return crc; } EXPORT_SYMBOL_GPL(crc64_be); + +/** + * crc64_rocksoft - Calculate bitwise Rocksoft CRC64 + * @crc: seed value for computation. (u64)~0 for a new CRC calculation, or the + * previous crc64 value if computing incrementally. + * @p: pointer to buffer over which CRC64 is run + * @len: length of buffer @p + */ +u64 __pure crc64_rocksoft(u64 crc, const void *p, size_t len) +{ + const unsigned char *_p = p; + size_t i; + + for (i = 0; i < len; i++) + crc = (crc >> 8) ^ crc64rocksofttable[(crc & 0xff) ^ *_p++]; + + return crc ^ (u64)~0; +} +EXPORT_SYMBOL_GPL(crc64_rocksoft); diff --git a/lib/gen_crc64table.c b/lib/gen_crc64table.c index 094b43aef8db..55e222acd0b8 100644 --- a/lib/gen_crc64table.c +++ b/lib/gen_crc64table.c @@ -17,10 +17,30 @@ #include #define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL +#define CRC64_ROCKSOFT_POLY 0x9A6C9329AC4BC9B5ULL static uint64_t crc64_table[256] = {0}; +static uint64_t crc64_rocksoft_table[256] = {0}; -static void generate_crc64_table(void) +static void generate_reflected_crc64_table(uint64_t table[256], uint64_t poly) +{ + uint64_t i, j, c, crc; + + for (i = 0; i < 256; i++) { + crc = 0ULL; + c = i; + + for (j = 0; j < 8; j++) { + if ((crc ^ (c >> j)) & 1) + crc = (crc >> 1) ^ poly; + else + crc >>= 1; + } + table[i] = crc; + } +} + +static void generate_crc64_table(uint64_t table[256], uint64_t poly) { uint64_t i, j, c, crc; @@ -30,26 +50,22 @@ static void generate_crc64_table(void) for (j = 0; j < 8; j++) { if ((crc ^ c) & 0x8000000000000000ULL) - crc = (crc << 1) ^ CRC64_ECMA182_POLY; + crc = (crc << 1) ^ poly; else crc <<= 1; c <<= 1; } - crc64_table[i] = crc; + table[i] = crc; } } -static void print_crc64_table(void) +static void output_table(uint64_t table[256]) { int i; - printf("/* this file is generated - do not edit */\n\n"); - printf("#include \n"); - printf("#include \n\n"); - printf("static const u64 ____cacheline_aligned crc64table[256] = {\n"); for (i = 0; i < 256; i++) { - printf("\t0x%016" PRIx64 "ULL", crc64_table[i]); + printf("\t0x%016" PRIx64 "ULL", table[i]); if (i & 0x1) printf(",\n"); else @@ -58,9 +74,22 @@ static void print_crc64_table(void) printf("};\n"); } +static void print_crc64_tables(void) +{ + printf("/* this file is generated - do not edit */\n\n"); + printf("#include \n"); + printf("#include \n\n"); + printf("static const u64 ____cacheline_aligned crc64table[256] = {\n"); + output_table(crc64_table); + + printf("\nstatic const u64 ____cacheline_aligned crc64rocksofttable[256] = {\n"); + output_table(crc64_rocksoft_table); +} + int main(int argc, char *argv[]) { - generate_crc64_table(); - print_crc64_table(); + generate_crc64_table(crc64_table, CRC64_ECMA182_POLY); + generate_reflected_crc64_table(crc64_rocksoft_table, CRC64_ROCKSOFT_POLY); + print_crc64_tables(); return 0; }