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 <sxwjean@gmail.com>
Subject: [PATCH 1/2] mm/memremap.c: Add pfn_to_devmap_page() to get page in ZONE_DEVICE
Date: Sun, 9 Jan 2022 21:05:14 +0800 [thread overview]
Message-ID: <20220109130515.140092-2-sxwjean@me.com> (raw)
In-Reply-To: <20220109130515.140092-1-sxwjean@me.com>
From: Xiongwei Song <sxwjean@gmail.com>
when requesting page information by /proc/kpage*, the pages in ZONE_DEVICE
were missed. 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.
Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
---
include/linux/memremap.h | 8 ++++++++
mm/memremap.c | 42 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 50 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..072dbe6ab81c 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -494,6 +494,48 @@ 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 and return page pointer.
+ */
+struct page *pfn_to_devmap_page(unsigned long pfn, struct dev_pagemap **pgmap)
+{
+ unsigned long nr = pfn_to_section_nr(pfn);
+ struct mem_section *ms;
+ struct page *page = NULL;
+
+ if (nr >= NR_MEM_SECTIONS)
+ return NULL;
+
+ if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) && !pfn_valid(pfn))
+ return NULL;
+
+ ms = __nr_to_section(nr);
+ if (!valid_section(ms))
+ return NULL;
+ if (!pfn_section_valid(ms, pfn))
+ return NULL;
+
+ /*
+ * Two types of sections may include valid pfns:
+ * - The pfns of section belong to ZONE_DEVICE and ZONE_{NORMAL,MOVABLE}
+ * at the same time.
+ * - All pfns in one section are offline but valid.
+ */
+ if (!online_device_section(ms) && online_section(ms))
+ return NULL;
+
+ *pgmap = get_dev_pagemap(pfn, NULL);
+ if (*pgmap)
+ page = pfn_to_page(pfn);
+
+ return page;
+}
+EXPORT_SYMBOL_GPL(pfn_to_devmap_page);
+
#ifdef CONFIG_DEV_PAGEMAP_OPS
void free_devmap_managed_page(struct page *page)
{
--
2.30.2
next prev parent reply other threads:[~2022-01-09 13:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-09 13:05 [PATCH 0/2] Add support for getting page info of ZONE_DEVICE by /proc/kpage* sxwjean
2022-01-09 13:05 ` sxwjean [this message]
2022-01-10 8:16 ` [PATCH 1/2] mm/memremap.c: Add pfn_to_devmap_page() to get page in ZONE_DEVICE David Hildenbrand
2022-01-10 9:30 ` Xiongwei Song
2022-01-09 13:05 ` [PATCH 2/2] proc: Add getting pages info of ZONE_DEVICE support sxwjean
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