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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2F9CFC433B4 for ; Tue, 18 May 2021 15:38:05 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 9B105611BF for ; Tue, 18 May 2021 15:38:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9B105611BF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ju8SM0DJVBOwjQSh8kJIJT+r8Uv2nYnXgA5D6/13ZaQ=; b=YuAkqRYUJt/471DV0MLsV6Z2r CTeqvBSNAKVXquCT8We3iEX7enzb3PolD2mkac2hAqq3p6tprZrAltf3xiDvYFvB8ATHKIl81tJkz LKCYmtOc/1D8r7BVO+BSxGJKXYjAR5/OirpkoWcujCLK0vb4UEKvyp3GJjnSI+PakEVjYRs6OZsX+ 1erXCPoFD3fP9FBa4c6PwiaPFcoI/EuMJtmUYH3F15ucant1rZlZUlCa8JH/wNS+N6hsyZDn7on/w GVc0dbVp6M+cJn/GdEonDSgPM7CVUDmvrJizzcNqf2RcIyCm00dScdP8fAd7arc/LSRvtGPmNw+kP ysWpGycxg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lj1lZ-001CCG-Bh; Tue, 18 May 2021 15:36:17 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lj1lW-001CBq-HQ for linux-arm-kernel@desiato.infradead.org; Tue, 18 May 2021 15:36:14 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=CJM3Z6IA7WDT+TUjIoqQwSqe+ziJIQDoUaI1ldNxfl0=; b=jvCdUGhm208ycvvPilbvG6k8vs A8fLzMPlJ8T7sSTSWKyWmHYuuwuocD+OQ9ZIzrnpIeObBDxcwn0cZ4mJuhzIfm+6G7pTvsfFBXOM/ MnFewi72m/6dSvii9ghrY3VvgsWp6DzpctrgBxzQMuOlViJnNSV1/XYEN2msEKJnOlD9MC4IzaJCG ckVqlCUSrVUhHJnUHyYEtGgsJ0bm8h+kb43VJago1r4Z0TicRt+G7gplkboOLb4IIMpY8mFYt6FCK P5I4cepfAyC1Kye8U+SqaaZIXm5udCuPPahJW7gVbDEg9967QVIRaKZJhdtJucEB9I18opn1egqMn t8fsdgEQ==; Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lj1lT-00Elo6-Lc for linux-arm-kernel@lists.infradead.org; Tue, 18 May 2021 15:36:13 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1CADDED1; Tue, 18 May 2021 08:36:09 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.6.226]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EB3913F73B; Tue, 18 May 2021 08:36:06 -0700 (PDT) Date: Tue, 18 May 2021 16:36:03 +0100 From: Mark Rutland To: Fuad Tabba Cc: linux-arm-kernel@lists.infradead.org, will@kernel.org, catalin.marinas@arm.com, maz@kernel.org, ardb@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, robin.murphy@arm.com Subject: Re: [PATCH v2 03/16] arm64: Do not enable uaccess for invalidate_icache_range Message-ID: <20210518153603.GK82842@C02TD0UTHF1T.local> References: <20210517075124.152151-1-tabba@google.com> <20210517075124.152151-4-tabba@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210517075124.152151-4-tabba@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210518_083611_779488_43EC24A9 X-CRM114-Status: GOOD ( 19.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, May 17, 2021 at 08:51:11AM +0100, Fuad Tabba wrote: > invalidate_icache_range() works on the kernel linear map, and > doesn't need uaccess. Remove the code that toggles > uaccess_ttbr0_enable, as well as the code that emits an entry > into the exception table (via the macro > invalidate_icache_by_line). > > Changes return type of invalidate_icache_range() from int (which > used to indicate a fault) to void, since it doesn't need uaccess > and won't fault. Note that return value was never checked by any > of the callers. > > No functional change intended. > Possible performance impact due to the reduced number of > instructions. > > Reported-by: Catalin Marinas > Reported-by: Will Deacon > Link: https://lore.kernel.org/linux-arch/20200511110014.lb9PEahJ4hVOYrbwIb_qUHXyNy9KQzNFdb_I3YlzY6A@z/ > Signed-off-by: Fuad Tabba > --- > arch/arm64/include/asm/cacheflush.h | 2 +- > arch/arm64/mm/cache.S | 11 +---------- > 2 files changed, 2 insertions(+), 11 deletions(-) > > diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h > index 52e5c1623224..a586afa84172 100644 > --- a/arch/arm64/include/asm/cacheflush.h > +++ b/arch/arm64/include/asm/cacheflush.h > @@ -57,7 +57,7 @@ > * - size - region size > */ > extern void __flush_icache_range(unsigned long start, unsigned long end); > -extern int invalidate_icache_range(unsigned long start, unsigned long end); > +extern void invalidate_icache_range(unsigned long start, unsigned long end); > extern void __flush_dcache_area(void *addr, size_t len); > extern void __inval_dcache_area(void *addr, size_t len); > extern void __clean_dcache_area_poc(void *addr, size_t len); > diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S > index 092f73acdf9a..6babaaf34f17 100644 > --- a/arch/arm64/mm/cache.S > +++ b/arch/arm64/mm/cache.S > @@ -105,21 +105,12 @@ SYM_FUNC_END(__flush_cache_user_range) > */ > SYM_FUNC_START(invalidate_icache_range) > alternative_if ARM64_HAS_CACHE_DIC > - mov x0, xzr > isb > ret > alternative_else_nop_endif > > - uaccess_ttbr0_enable x2, x3, x4 > - > - invalidate_icache_by_line x0, x1, x2, x3, 1, 2f > - mov x0, xzr > -1: > - uaccess_ttbr0_disable x1, x2 > + invalidate_icache_by_line x0, x1, x2, x3, 0, 0f This all looks good to me, but I'd prefer that we didn't have to pass a fake label. I think if you use the approach I suggested on the prior patch, this can be: invalidate_icache_by_line x0, x1, x2, x3 ... which I think makes it clearer that there's no fixup. Thanks, Mark. > ret > -2: > - mov x0, #-EFAULT > - b 1b > SYM_FUNC_END(invalidate_icache_range) > > /* > -- > 2.31.1.751.gd2f1c929bd-goog > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel