From patchwork Fri Mar 5 12:21:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 394376 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 EB34CC433E9 for ; Fri, 5 Mar 2021 12:34:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE5486502F for ; Fri, 5 Mar 2021 12:34:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230322AbhCEMe2 (ORCPT ); Fri, 5 Mar 2021 07:34:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:45548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232173AbhCEMd7 (ORCPT ); Fri, 5 Mar 2021 07:33:59 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1FFA964F23; Fri, 5 Mar 2021 12:33:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614947639; bh=FTAW4QqHvb29GyAjqVidyQcYMxSOuWoKsmGr0LTjH3g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gGgH44xV6yfgcOAWf6dJaFm+QA5mz5TPkCMe0eV8pK4TQiKQoeJCOMgHXuRvclPOx p9p9jdO1xC5KrMUTwmoftMFC9gzLlNy6IXEFtSoyw+oP/y+Rc1DXcRQhgNysd+yNwk aYJN/b2JO7j6StDgCaiXTbHqrEjJhK1AljQNfnEo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Burton , Alexander Lobakin , =?utf-8?q?Philippe_Math?= =?utf-8?q?ieu-Daud=C3=A9?= , linux-mips@vger.kernel.org, Florian Westphal Subject: [PATCH 5.4 23/72] MIPS: Drop 32-bit asm string functions Date: Fri, 5 Mar 2021 13:21:25 +0100 Message-Id: <20210305120858.481470995@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210305120857.341630346@linuxfoundation.org> References: <20210305120857.341630346@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paul Burton commit 3c0be5849259b729580c23549330973a2dd513a2 upstream. We have assembly implementations of strcpy(), strncpy(), strcmp() & strncmp() which: - Are simple byte-at-a-time loops with no particular optimizations. As a comment in the code describes, they're "rather naive". - Offer no clear performance advantage over the generic C implementations - in microbenchmarks performed by Alexander Lobakin the asm functions sometimes win & sometimes lose, but generally not by large margins in either direction. - Don't support 64-bit kernels, where we already make use of the generic C implementations. - Tend to bloat kernel code size due to inlining. - Don't support CONFIG_FORTIFY_SOURCE. - Won't support nanoMIPS without rework. For all of these reasons, delete the asm implementations & make use of the generic C implementations for 32-bit kernels just like we already do for 64-bit kernels. Signed-off-by: Paul Burton URL: https://lore.kernel.org/linux-mips/a2a35f1cf58d6db19eb4af9b4ae21e35@dlink.ru/ Cc: Alexander Lobakin Reviewed-by: Philippe Mathieu-Daudé Cc: linux-mips@vger.kernel.org Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman --- arch/mips/include/asm/string.h | 121 ----------------------------------------- 1 file changed, 121 deletions(-) --- a/arch/mips/include/asm/string.h +++ b/arch/mips/include/asm/string.h @@ -10,127 +10,6 @@ #ifndef _ASM_STRING_H #define _ASM_STRING_H - -/* - * Most of the inline functions are rather naive implementations so I just - * didn't bother updating them for 64-bit ... - */ -#ifdef CONFIG_32BIT - -#ifndef IN_STRING_C - -#define __HAVE_ARCH_STRCPY -static __inline__ char *strcpy(char *__dest, __const__ char *__src) -{ - char *__xdest = __dest; - - __asm__ __volatile__( - ".set\tnoreorder\n\t" - ".set\tnoat\n" - "1:\tlbu\t$1,(%1)\n\t" - "addiu\t%1,1\n\t" - "sb\t$1,(%0)\n\t" - "bnez\t$1,1b\n\t" - "addiu\t%0,1\n\t" - ".set\tat\n\t" - ".set\treorder" - : "=r" (__dest), "=r" (__src) - : "0" (__dest), "1" (__src) - : "memory"); - - return __xdest; -} - -#define __HAVE_ARCH_STRNCPY -static __inline__ char *strncpy(char *__dest, __const__ char *__src, size_t __n) -{ - char *__xdest = __dest; - - if (__n == 0) - return __xdest; - - __asm__ __volatile__( - ".set\tnoreorder\n\t" - ".set\tnoat\n" - "1:\tlbu\t$1,(%1)\n\t" - "subu\t%2,1\n\t" - "sb\t$1,(%0)\n\t" - "beqz\t$1,2f\n\t" - "addiu\t%0,1\n\t" - "bnez\t%2,1b\n\t" - "addiu\t%1,1\n" - "2:\n\t" - ".set\tat\n\t" - ".set\treorder" - : "=r" (__dest), "=r" (__src), "=r" (__n) - : "0" (__dest), "1" (__src), "2" (__n) - : "memory"); - - return __xdest; -} - -#define __HAVE_ARCH_STRCMP -static __inline__ int strcmp(__const__ char *__cs, __const__ char *__ct) -{ - int __res; - - __asm__ __volatile__( - ".set\tnoreorder\n\t" - ".set\tnoat\n\t" - "lbu\t%2,(%0)\n" - "1:\tlbu\t$1,(%1)\n\t" - "addiu\t%0,1\n\t" - "bne\t$1,%2,2f\n\t" - "addiu\t%1,1\n\t" - "bnez\t%2,1b\n\t" - "lbu\t%2,(%0)\n\t" -#if defined(CONFIG_CPU_R3000) - "nop\n\t" -#endif - "move\t%2,$1\n" - "2:\tsubu\t%2,$1\n" - "3:\t.set\tat\n\t" - ".set\treorder" - : "=r" (__cs), "=r" (__ct), "=r" (__res) - : "0" (__cs), "1" (__ct)); - - return __res; -} - -#endif /* !defined(IN_STRING_C) */ - -#define __HAVE_ARCH_STRNCMP -static __inline__ int -strncmp(__const__ char *__cs, __const__ char *__ct, size_t __count) -{ - int __res; - - __asm__ __volatile__( - ".set\tnoreorder\n\t" - ".set\tnoat\n" - "1:\tlbu\t%3,(%0)\n\t" - "beqz\t%2,2f\n\t" - "lbu\t$1,(%1)\n\t" - "subu\t%2,1\n\t" - "bne\t$1,%3,3f\n\t" - "addiu\t%0,1\n\t" - "bnez\t%3,1b\n\t" - "addiu\t%1,1\n" - "2:\n\t" -#if defined(CONFIG_CPU_R3000) - "nop\n\t" -#endif - "move\t%3,$1\n" - "3:\tsubu\t%3,$1\n\t" - ".set\tat\n\t" - ".set\treorder" - : "=r" (__cs), "=r" (__ct), "=r" (__count), "=r" (__res) - : "0" (__cs), "1" (__ct), "2" (__count)); - - return __res; -} -#endif /* CONFIG_32BIT */ - #define __HAVE_ARCH_MEMSET extern void *memset(void *__s, int __c, size_t __count);