From patchwork Mon Aug 24 18:27:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 11733981 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8CC451575 for ; Mon, 24 Aug 2020 18:29:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5FA722087D for ; Mon, 24 Aug 2020 18:29:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FA722087D 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 1A7378E0010; Mon, 24 Aug 2020 14:29:01 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 133688E000A; Mon, 24 Aug 2020 14:29:01 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F16F48E0010; Mon, 24 Aug 2020 14:29:00 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0215.hostedemail.com [216.40.44.215]) by kanga.kvack.org (Postfix) with ESMTP id D59628E000A for ; Mon, 24 Aug 2020 14:29:00 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 968F0362B for ; Mon, 24 Aug 2020 18:29:00 +0000 (UTC) X-FDA: 77186298840.27.cloud04_3711ec127055 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin27.hostedemail.com (Postfix) with ESMTP id 6A6323D663 for ; Mon, 24 Aug 2020 18:29:00 +0000 (UTC) X-Spam-Summary: 1,0,0,d01c96c676b66853,d41d8cd98f00b204,cmainas@kernel.org,,RULES_HIT:41:355:379:541:800:960:966:973:981:988:989:1260:1311:1314:1345:1359:1431:1437:1515:1535:1544:1711:1730:1747:1777:1792:2196:2199:2393:2553:2559:2562:2730:3138:3139:3140:3141:3142:3355:3865:3867:3868:3870:3871:3872:4321:4385:4605:5007:6261:6742:7576:7875:10004:11026:11232:11233:11473:11658:11914:12043:12291:12296:12297:12438:12517:12519:12555:12679:12986:13180:13229:13894:14096:14181:14394:14721:21080:21230:21324:21433:21451:21627:21990:30012:30051:30054:30069:30075:30090,0,RBL:198.145.29.99:@kernel.org:.lbl8.mailshell.net-62.2.0.100 64.100.201.201;04y8g9da315hr8m9gq94k3cdd6hycycmei1mx3ueyzd16hy9fys3ua3mo1hd98p.33dq776hz9zmhgj5poneah73bucqnzafhucr7hntiq9o48b7jtak9sbdfckdq7e.6-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:23,LUA_SUMMARY:none X-HE-Tag: cloud04_3711ec127055 X-Filterd-Recvd-Size: 5562 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf39.hostedemail.com (Postfix) with ESMTP for ; Mon, 24 Aug 2020 18:28:59 +0000 (UTC) Received: from localhost.localdomain (unknown [95.146.230.145]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EAF362078D; Mon, 24 Aug 2020 18:28:56 +0000 (UTC) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org Cc: linux-mm@kvack.org, linux-arch@vger.kernel.org, Will Deacon , Dave P Martin , Vincenzo Frascino , Szabolcs Nagy , Kevin Brodsky , Andrey Konovalov , Peter Collingbourne , Andrew Morton , Steven Price Subject: [PATCH v8 24/28] mm: Add arch hooks for saving/restoring tags Date: Mon, 24 Aug 2020 19:27:54 +0100 Message-Id: <20200824182758.27267-25-catalin.marinas@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200824182758.27267-1-catalin.marinas@arm.com> References: <20200824182758.27267-1-catalin.marinas@arm.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 6A6323D663 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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: From: Steven Price Arm's Memory Tagging Extension (MTE) adds some metadata (tags) 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() Signed-off-by: Steven Price [catalin.marinas@arm.com: add unlock_page() on the error path] [catalin.marinas@arm.com: dropped the _tags suffix] Signed-off-by: Catalin Marinas Acked-by: Andrew Morton --- Notes: v6: - Added comment on where the arch code should define the overriding macros (asm/pgtable.h). - Dropped _tags suffix from arch_swap_restore_tags(). New in v4. include/linux/pgtable.h | 28 ++++++++++++++++++++++++++++ mm/page_io.c | 10 ++++++++++ mm/shmem.c | 6 ++++++ mm/swapfile.c | 2 ++ 4 files changed, 46 insertions(+) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index e8cbc2e795d5..dc3b74129fbc 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -633,6 +633,34 @@ static inline int arch_unmap_one(struct mm_struct *mm, } #endif +/* + * Allow architectures to preserve additional metadata associated with + * swapped-out pages. The corresponding __HAVE_ARCH_SWAP_* macros and function + * prototypes must be defined in the arch-specific asm/pgtable.h file. + */ +#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 +static inline void arch_swap_restore(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 e485a6e8a6cd..4ca28aad0d94 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -252,6 +252,16 @@ int swap_writepage(struct page *page, struct writeback_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 = arch_prepare_to_swap(page); + if (ret) { + set_page_dirty(page); + unlock_page(page); + goto out; + } if (frontswap_store(page) == 0) { set_page_writeback(page); unlock_page(page); diff --git a/mm/shmem.c b/mm/shmem.c index ec94f4c7851e..e57d3314dc4b 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1734,6 +1734,12 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, } wait_on_page_writeback(page); + /* + * Some architectures may have to restore extra metadata to the + * physical page after reading from swap. + */ + arch_swap_restore(swap, page); + if (shmem_should_replace_page(page, gfp)) { error = shmem_replace_page(&page, gfp, info, index); if (error) diff --git a/mm/swapfile.c b/mm/swapfile.c index 12f59e641b5e..4b1d1a04e327 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -717,6 +717,7 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset, else swap_slot_free_notify = NULL; while (offset <= 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); @@ -2682,6 +2683,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile) frontswap_map = 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);