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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 93D13C55185 for ; Wed, 22 Apr 2020 14:25:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 63F972082E for ; Wed, 22 Apr 2020 14:25:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63F972082E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7C82B8E002A; Wed, 22 Apr 2020 10:25:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 729198E0003; Wed, 22 Apr 2020 10:25:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5A49E8E002A; Wed, 22 Apr 2020 10:25:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0054.hostedemail.com [216.40.44.54]) by kanga.kvack.org (Postfix) with ESMTP id 3D79E8E0003 for ; Wed, 22 Apr 2020 10:25:46 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id E97CC2839 for ; Wed, 22 Apr 2020 14:25:45 +0000 (UTC) X-FDA: 76735714650.25.swing81_4f647bebf3752 X-HE-Tag: swing81_4f647bebf3752 X-Filterd-Recvd-Size: 4825 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Wed, 22 Apr 2020 14:25:45 +0000 (UTC) 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 A482F1045; Wed, 22 Apr 2020 07:25:44 -0700 (PDT) Received: from e112269-lin.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3944B3F68F; Wed, 22 Apr 2020 07:25:43 -0700 (PDT) From: Steven Price To: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Cc: Steven Price , linux-arch@vger.kernel.org, Andrew Morton , Arnd Bergmann , Catalin Marinas , Hugh Dickins , Vincenzo Frascino , Will Deacon Subject: [PATCH 2/4] mm: Add arch hooks for saving/restoring tags Date: Wed, 22 Apr 2020 15:25:28 +0100 Message-Id: <20200422142530.32619-3-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200422142530.32619-1-steven.price@arm.com> References: <20200422142530.32619-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Arm's Memory Tagging Extension (MTE) adds some metadata (taga) to every physical page, when swapping pages out to disk it is necessary to save these tags, and later restore them when reading the pages back. Add some hooks along with dummy implementations to enable the arch code to handle this. Three new hooks are added to the swap code: * arch_prepare_to_swap() and * arch_swap_invalidate_page() / arch_swap_invalidate_area(). One new hook is added to shmem: * arch_swap_restore_tags() Signed-off-by: Steven Price --- include/asm-generic/pgtable.h | 23 +++++++++++++++++++++++ mm/page_io.c | 6 ++++++ mm/shmem.c | 6 ++++++ mm/swapfile.c | 2 ++ 4 files changed, 37 insertions(+) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.= h index 329b8c8ca703..306cee75b9ec 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -475,6 +475,29 @@ static inline int arch_unmap_one(struct mm_struct *m= m, } #endif =20 +#ifndef __HAVE_ARCH_PREPARE_TO_SWAP +static inline int arch_prepare_to_swap(struct page *page) +{ + return 0; +} +#endif + +#ifndef __HAVE_ARCH_SWAP_INVALIDATE +static inline void arch_swap_invalidate_page(int type, pgoff_t offset) +{ +} + +static inline void arch_swap_invalidate_area(int type) +{ +} +#endif + +#ifndef __HAVE_ARCH_SWAP_RESTORE_TAGS +static inline void arch_swap_restore_tags(swp_entry_t entry, struct page= *page) +{ +} +#endif + #ifndef __HAVE_ARCH_PGD_OFFSET_GATE #define pgd_offset_gate(mm, addr) pgd_offset(mm, addr) #endif diff --git a/mm/page_io.c b/mm/page_io.c index 76965be1d40e..7baee316ac99 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -253,6 +253,12 @@ int swap_writepage(struct page *page, struct writeba= ck_control *wbc) unlock_page(page); goto out; } + /* Arch code may have to preserve more data + * than just the page contents, e.g. memory tags + */ + ret =3D arch_prepare_to_swap(page); + if (ret) + goto out; if (frontswap_store(page) =3D=3D 0) { set_page_writeback(page); unlock_page(page); diff --git a/mm/shmem.c b/mm/shmem.c index 73754ed7af69..1010b91f267e 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1658,6 +1658,12 @@ static int shmem_swapin_page(struct inode *inode, = pgoff_t index, } wait_on_page_writeback(page); =20 + /* + * Some architectures may have to restore extra metadata to the + * physical page after reading from swap + */ + arch_swap_restore_tags(swap, page); + if (shmem_should_replace_page(page, gfp)) { error =3D shmem_replace_page(&page, gfp, info, index); if (error) diff --git a/mm/swapfile.c b/mm/swapfile.c index 5871a2aa86a5..b39c6520b0cf 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -722,6 +722,7 @@ static void swap_range_free(struct swap_info_struct *= si, unsigned long offset, else swap_slot_free_notify =3D NULL; while (offset <=3D end) { + arch_swap_invalidate_page(si->type, offset); frontswap_invalidate_page(si->type, offset); if (swap_slot_free_notify) swap_slot_free_notify(si->bdev, offset); @@ -2645,6 +2646,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, speci= alfile) frontswap_map =3D frontswap_map_get(p); spin_unlock(&p->lock); spin_unlock(&swap_lock); + arch_swap_invalidate_area(p->type); frontswap_invalidate_area(p->type); frontswap_map_set(p, NULL); mutex_unlock(&swapon_mutex); --=20 2.20.1