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(unknown [120.245.2.88]) by mr85p00im-zteg06011501.me.com (Postfix) with ESMTPSA id 680ED480EE0; Wed, 12 Jan 2022 14:36:13 +0000 (UTC) From: sxwjean@me.com To: akpm@linux-foundation.org, david@redhat.com, mhocko@suse.com, dan.j.williams@intel.com, osalvador@suse.de, naoya.horiguchi@nec.com, thunder.leizhen@huawei.com Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Xiongwei Song Subject: [PATCH v3 1/2] mm/memremap.c: Add pfn_to_devmap_page() to get page in ZONE_DEVICE Date: Wed, 12 Jan 2022 22:35:16 +0800 Message-Id: <20220112143517.262143-2-sxwjean@me.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220112143517.262143-1-sxwjean@me.com> References: <20220112143517.262143-1-sxwjean@me.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: =?utf-8?q?vendor=3Dfsecure_engine=3D1=2E1=2E170-?= =?utf-8?q?22c6f66c430a71ce266a39bfe25bc2903e8d5c8f=3A6=2E0=2E425=2C18=2E0?= =?utf-8?q?=2E790=2C17=2E0=2E607=2E475=2E0000000_definitions=3D2022-01-12=5F?= =?utf-8?q?04=3A2022-01-11=5F01=2C2022-01-12=5F04=2C2020-04-07=5F01_signatur?= =?utf-8?q?es=3D0?= X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 bulkscore=0 malwarescore=0 mlxscore=0 adultscore=0 clxscore=1015 suspectscore=0 phishscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2201120095 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 76963100018 X-Stat-Signature: 5eq653j9aowtjchtbf79aa78w7yap1k4 Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=me.com header.s=1a1hai header.b=GafK0KHp; spf=pass (imf05.hostedemail.com: domain of sxwjean@me.com designates 17.58.23.182 as permitted sender) smtp.mailfrom=sxwjean@me.com; dmarc=pass (policy=quarantine) header.from=me.com X-HE-Tag: 1641998200-443174 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: Xiongwei Song when requesting page information by /proc/kpage*, the pages in ZONE_DEVICE were ignored . We need a function to help on this. The pfn_to_devmap_page() function like pfn_to_online_page(), but only concerns the pages in ZONE_DEVICE. Suggested-by: David Hildenbrand Signed-off-by: Xiongwei Song --- v3: Before returning page pointer, check validity of page by pgmap_pfn_valid(). v2: Simplify pfn_to_devmap_page() as David suggested. --- include/linux/memremap.h | 8 ++++++++ mm/memremap.c | 19 +++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/linux/memremap.h b/include/linux/memremap.h index c0e9d35889e8..621723e9c4a5 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -137,6 +137,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap); void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap); struct dev_pagemap *get_dev_pagemap(unsigned long pfn, struct dev_pagemap *pgmap); +struct page *pfn_to_devmap_page(unsigned long pfn, + struct dev_pagemap **pgmap); bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn); unsigned long vmem_altmap_offset(struct vmem_altmap *altmap); @@ -166,6 +168,12 @@ static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn, return NULL; } +static inline struct page *pfn_to_devmap_page(unsigned long pfn, + struct dev_pagemap **pgmap) +{ + return NULL; +} + static inline bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn) { return false; diff --git a/mm/memremap.c b/mm/memremap.c index 5a66a71ab591..782309b74d71 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -494,6 +494,25 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn, } EXPORT_SYMBOL_GPL(get_dev_pagemap); +/** + * pfn_to_devmap_page - get page pointer which belongs to dev_pagemap by @pfn + * @pfn: page frame number to lookup page_map + * @pgmap: to save pgmap address which is for putting reference + * + * If @pgmap is non-NULL, then pfn is on ZONE_DEVICE. Meanwhile check if + * pfn is valid in @pgmap, if yes return page pointer. + */ +struct page *pfn_to_devmap_page(unsigned long pfn, struct dev_pagemap **pgmap) +{ + if (pfn_valid(pfn)) { + *pgmap = get_dev_pagemap(pfn, NULL); + if (*pgmap && pgmap_pfn_valid(*pgmap, pfn)) + return pfn_to_page(pfn); + } + + return NULL; +} + #ifdef CONFIG_DEV_PAGEMAP_OPS void free_devmap_managed_page(struct page *page) {