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{ "id": 2219754, "url": "http://patchwork.ozlabs.org/api/1.1/covers/2219754/?format=api", "web_url": "http://patchwork.ozlabs.org/project/sparclinux/cover/20260404071720.3577290-1-songmuchun@bytedance.com/", "project": { "id": 10, "url": "http://patchwork.ozlabs.org/api/1.1/projects/10/?format=api", "name": "Linux SPARC Development ", "link_name": "sparclinux", "list_id": "sparclinux.vger.kernel.org", "list_email": "sparclinux@vger.kernel.org", "web_url": null, "scm_url": null, "webscm_url": null }, "msgid": "<20260404071720.3577290-1-songmuchun@bytedance.com>", "date": "2026-04-04T07:17:04", "name": "[0/5] mm/sparse-vmemmap: provide generic vmemmap_set_pmd() and vmemmap_check_pmd()", "submitter": { "id": 78930, "url": "http://patchwork.ozlabs.org/api/1.1/people/78930/?format=api", "name": "Muchun Song", "email": "songmuchun@bytedance.com" }, "mbox": "http://patchwork.ozlabs.org/project/sparclinux/cover/20260404071720.3577290-1-songmuchun@bytedance.com/mbox/", "series": [ { "id": 498702, "url": "http://patchwork.ozlabs.org/api/1.1/series/498702/?format=api", "web_url": "http://patchwork.ozlabs.org/project/sparclinux/list/?series=498702", "date": "2026-04-04T07:17:04", "name": "mm/sparse-vmemmap: provide generic vmemmap_set_pmd() and vmemmap_check_pmd()", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/498702/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2219754/comments/", "headers": { "Return-Path": "\n <SRS0=dZTV=CD=vger.kernel.org=sparclinux+bounces-6631-patchwork-incoming=ozlabs.org@ozlabs.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "sparclinux@vger.kernel.org" ], "Delivered-To": [ "patchwork-incoming@legolas.ozlabs.org", "patchwork-incoming@ozlabs.org" ], "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=bytedance.com header.i=@bytedance.com\n header.a=rsa-sha256 header.s=google header.b=bb8eb65R;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org\n (client-ip=2404:9400:2221:ea00::3; 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Miller\" <davem@davemloft.net>,\n\tAndreas Larsson <andreas@gaisler.com>,\n\tAndrew Morton <akpm@linux-foundation.org>,\n\tDavid Hildenbrand <david@kernel.org>", "Cc": "Muchun Song <muchun.song@linux.dev>,\n\tMuchun Song <songmuchun@bytedance.com>,\n\tWANG Xuerui <kernel@xen0n.name>,\n\tAlexandre Ghiti <alex@ghiti.fr>,\n\tLorenzo Stoakes <ljs@kernel.org>,\n\t\"Liam R. Howlett\" <Liam.Howlett@oracle.com>,\n\tVlastimil Babka <vbabka@kernel.org>,\n\tMike Rapoport <rppt@kernel.org>,\n\tSuren Baghdasaryan <surenb@google.com>,\n\tMichal Hocko <mhocko@suse.com>,\n\tRyan Roberts <ryan.roberts@arm.com>,\n\tKevin Brodsky <kevin.brodsky@arm.com>,\n\tDev Jain <dev.jain@arm.com>,\n\tAnshuman Khandual <anshuman.khandual@arm.com>,\n\tYang Shi <yang@os.amperecomputing.com>,\n\tChaitanya S Prakash <chaitanyas.prakash@arm.com>,\n\tYuquan Wang <wangyuquan1236@phytium.com.cn>,\n\tPetr Tesarik <ptesarik@suse.com>,\n\tAustin Kim <austin.kim@lge.com>,\n\t\"Vishal Moola (Oracle)\" <vishal.moola@gmail.com>,\n\tJunhui Liu <junhui.liu@pigmoral.tech>,\n\t\"Matthew Wilcox (Oracle)\" <willy@infradead.org>,\n\tAlex Shi <alexs@kernel.org>,\n\tChengkaitao <chengkaitao@kylinos.cn>,\n\tlinux-arm-kernel@lists.infradead.org,\n\tlinux-kernel@vger.kernel.org,\n\tloongarch@lists.linux.dev,\n\tlinux-riscv@lists.infradead.org,\n\tsparclinux@vger.kernel.org,\n\tlinux-mm@kvack.org", "Subject": "[PATCH 0/5] mm/sparse-vmemmap: provide generic vmemmap_set_pmd() and\n vmemmap_check_pmd()", "Date": "Sat, 4 Apr 2026 15:17:04 +0800", "Message-Id": "<20260404071720.3577290-1-songmuchun@bytedance.com>", "X-Mailer": "git-send-email 2.20.1", "Precedence": "bulk", "X-Mailing-List": "sparclinux@vger.kernel.org", "List-Id": "<sparclinux.vger.kernel.org>", "List-Subscribe": "<mailto:sparclinux+subscribe@vger.kernel.org>", "List-Unsubscribe": "<mailto:sparclinux+unsubscribe@vger.kernel.org>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-Spam-Status": "No, score=-1.2 required=5.0 tests=ARC_SIGNED,ARC_VALID,\n\tDKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DMARC_PASS,\n\tHEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,\n\tSPF_PASS autolearn=disabled version=4.0.1", "X-Spam-Checker-Version": "SpamAssassin 4.0.1 (2024-03-25) on gandalf.ozlabs.org" }, "content": "The two weak functions vmemmap_set_pmd() and vmemmap_check_pmd() are\ncurrently no-ops on every architecture, forcing each platform that needs\nthem to duplicate the same handful of lines. Provide a generic implementation:\n\n- vmemmap_set_pmd() simply sets a huge PMD with PAGE_KERNEL protection.\n\n- vmemmap_check_pmd() verifies that the PMD is present and leaf,\n then calls the existing vmemmap_verify() helper.\n\nArchitectures that need special handling can continue to override the\nweak symbols; everyone else gets the standard version for free.\n\nThis series drops the custom implementations in arm64, riscv, loongarch,\nand sparc, replacing them with the generic implementation introduced\nin the first patch.\n\nMuchun Song (5):\n mm/sparse-vmemmap: provide generic vmemmap_set_pmd() and\n vmemmap_check_pmd()\n arm64/mm: drop vmemmap_pmd helpers and use generic code\n riscv/mm: drop vmemmap_pmd helpers and use generic code\n loongarch/mm: drop vmemmap_check_pmd helper and use generic code\n sparc/mm: drop vmemmap_check_pmd helper and use generic code\n\n arch/arm64/mm/mmu.c | 14 --------------\n arch/loongarch/mm/init.c | 11 -----------\n arch/riscv/mm/init.c | 13 -------------\n arch/sparc/mm/init_64.c | 11 -----------\n mm/sparse-vmemmap.c | 7 ++++++-\n 5 files changed, 6 insertions(+), 50 deletions(-)" }