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 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 8A146C3DA4A for ; Tue, 20 Aug 2024 03:03:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:CC:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=HMkvpXVh3VJ0odf/pNWk62xd4y/S1nkaUXDWSHs3djg=; b=KRX1oQXGARLpQJ9tGmHSE5Tw6H 3hfz65H9BMYqpqWz2FmQJ0dkCDDRbi167f/CV1UYM9eOKLho5lNfgVkGbLqm5ab9xwVRyTYScKKhY +dnZFIA+9muaicGfr15uetjKSmwmnMGPnucLVTBvWOFg7212mM9m+auzEG2SN0QT+lo6s3gFDOxfQ V3ybljrSamipPmmL5QkkZ25td37jAwfc3iUThHn8hcmA5zZlQKv2BmSAGb2WtgviysJ1VZaHSSeOJ JzKja+y3ZMwI+OPL6BDJ/g3Gf0GbX+d3Dq0bQLOkX0+W4mnIbOuryCTdb0H8NoMOYcudtjuSviQMg uT95K2HA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgF97-00000003c2m-2YVl; Tue, 20 Aug 2024 03:02:57 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sgF8P-00000003buz-3GKh for linux-arm-kernel@lists.infradead.org; Tue, 20 Aug 2024 03:02:16 +0000 Received: from mail.maildlp.com (unknown [172.19.88.105]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4WnvMr41ryzfbXX; Tue, 20 Aug 2024 11:00:08 +0800 (CST) Received: from kwepemm600017.china.huawei.com (unknown [7.193.23.234]) by mail.maildlp.com (Postfix) with ESMTPS id 77715140138; Tue, 20 Aug 2024 11:02:08 +0800 (CST) Received: from [10.174.179.234] (10.174.179.234) by kwepemm600017.china.huawei.com (7.193.23.234) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 20 Aug 2024 11:02:06 +0800 Message-ID: <8257d76b-c700-89a6-0e29-f194d2e1cd61@huawei.com> Date: Tue, 20 Aug 2024 11:02:05 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH v12 4/6] arm64: support copy_mc_[user]_highpage() To: Jonathan Cameron CC: Mark Rutland , Catalin Marinas , Will Deacon , Andrew Morton , James Morse , Robin Murphy , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Michael Ellerman , Nicholas Piggin , Andrey Ryabinin , Alexander Potapenko , Christophe Leroy , Aneesh Kumar K.V , "Naveen N. Rao" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , , "H. Peter Anvin" , , , , , , Guohanjun References: <20240528085915.1955987-1-tongtiangen@huawei.com> <20240528085915.1955987-5-tongtiangen@huawei.com> <20240819125601.0000687b@Huawei.com> From: Tong Tiangen In-Reply-To: <20240819125601.0000687b@Huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.234] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemm600017.china.huawei.com (7.193.23.234) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240819_200214_397925_9B353EEF X-CRM114-Status: GOOD ( 20.94 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 在 2024/8/19 19:56, Jonathan Cameron 写道: > On Tue, 28 May 2024 16:59:13 +0800 > Tong Tiangen wrote: > >> Currently, many scenarios that can tolerate memory errors when copying page >> have been supported in the kernel[1~5], all of which are implemented by >> copy_mc_[user]_highpage(). arm64 should also support this mechanism. >> >> Due to mte, arm64 needs to have its own copy_mc_[user]_highpage() >> architecture implementation, macros __HAVE_ARCH_COPY_MC_HIGHPAGE and >> __HAVE_ARCH_COPY_MC_USER_HIGHPAGE have been added to control it. >> >> Add new helper copy_mc_page() which provide a page copy implementation with >> hardware memory error safe. The code logic of copy_mc_page() is the same as >> copy_page(), the main difference is that the ldp insn of copy_mc_page() >> contains the fixup type EX_TYPE_KACCESS_ERR_ZERO_ME_SAFE, therefore, the >> main logic is extracted to copy_page_template.S. >> >> [1] commit d302c2398ba2 ("mm, hwpoison: when copy-on-write hits poison, take page offline") >> [2] commit 1cb9dc4b475c ("mm: hwpoison: support recovery from HugePage copy-on-write faults") >> [3] commit 6b970599e807 ("mm: hwpoison: support recovery from ksm_might_need_to_copy()") >> [4] commit 98c76c9f1ef7 ("mm/khugepaged: recover from poisoned anonymous memory") >> [5] commit 12904d953364 ("mm/khugepaged: recover from poisoned file-backed memory") >> >> Signed-off-by: Tong Tiangen > Trivial stuff inline. > > Jonathan I'm sorry, I may not have understood what you meant. Where is the better place to do inline? :) Thanks, Tong. > > >> diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S >> index 5018ac03b6bf..50ef24318281 100644 >> --- a/arch/arm64/lib/mte.S >> +++ b/arch/arm64/lib/mte.S >> @@ -80,6 +80,35 @@ SYM_FUNC_START(mte_copy_page_tags) >> ret >> SYM_FUNC_END(mte_copy_page_tags) >> >> +#ifdef CONFIG_ARCH_HAS_COPY_MC >> +/* >> + * Copy the tags from the source page to the destination one wiht machine check safe > Spell check. > with > > Also, maybe reword given machine check doesn't make sense on arm64. OK. > > >> + * x0 - address of the destination page >> + * x1 - address of the source page >> + * Returns: >> + * x0 - Return 0 if copy success, or >> + * -EFAULT if anything goes wrong while copying. >> + */ >> +SYM_FUNC_START(mte_copy_mc_page_tags) >> + mov x2, x0 >> + mov x3, x1 >> + multitag_transfer_size x5, x6 >> +1: >> +KERNEL_ME_SAFE(2f, ldgm x4, [x3]) >> + stgm x4, [x2] >> + add x2, x2, x5 >> + add x3, x3, x5 >> + tst x2, #(PAGE_SIZE - 1) >> + b.ne 1b >> + >> + mov x0, #0 >> + ret >> + >> +2: mov x0, #-EFAULT >> + ret >> +SYM_FUNC_END(mte_copy_mc_page_tags) >> +#endif >> + >> /* >> * Read tags from a user buffer (one tag per byte) and set the corresponding >> * tags at the given kernel address. Used by PTRACE_POKEMTETAGS. >> diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c >> index a7bb20055ce0..ff0d9ceea2a4 100644 >> --- a/arch/arm64/mm/copypage.c >> +++ b/arch/arm64/mm/copypage.c >> @@ -40,3 +40,48 @@ void copy_user_highpage(struct page *to, struct page *from, > >> + >> +int copy_mc_user_highpage(struct page *to, struct page *from, >> + unsigned long vaddr, struct vm_area_struct *vma) >> +{ >> + int ret; >> + >> + ret = copy_mc_highpage(to, from); >> + if (!ret) >> + flush_dcache_page(to); > Personally I'd always keep the error out of line as it tends to be > more readable when reviewing a lot of code. > if (ret) > return ret; > > flush_dcache_page(to); > > return 0; This is more reasonable, and it is more readable to eliminate errors in time. Thanks, Tong. >> + >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(copy_mc_user_highpage); >> +#endif > > .