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From:   "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
To:     linux-mm@kvack.org
Cc:     damon@lists.linux.dev, linux-kernel@vger.kernel.org,
        akpm@linux-foundation.org, sj@kernel.org,
        "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Subject: [PATCH v3 1/4] mm/memory: Add vm_normal_folio()
Date:   Thu,  8 Dec 2022 12:35:00 -0800
Message-Id: <20221208203503.20665-2-vishal.moola@gmail.com>
In-Reply-To: <20221208203503.20665-1-vishal.moola@gmail.com>
References: <20221208203503.20665-1-vishal.moola@gmail.com>
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Introduce a wrapper function called vm_normal_folio(). This function
calls vm_normal_page() and returns the folio of the page found, or null
if no page is found.

This function allows callers to get a folio from a pte, which will
eventually allow them to completely replace their struct page variables
with struct folio instead.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h |  2 ++
 mm/memory.c        | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8bbcccbc5565..626ae0757bd3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1860,6 +1860,8 @@ static inline bool can_do_mlock(void) { return false; }
 extern int user_shm_lock(size_t, struct ucounts *);
 extern void user_shm_unlock(size_t, struct ucounts *);
 
+struct folio *vm_normal_folio(struct vm_area_struct *vma, unsigned long addr,
+			     pte_t pte);
 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte);
 struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
diff --git a/mm/memory.c b/mm/memory.c
index f88c351aecd4..1247c19c516c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -672,6 +672,16 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 	return pfn_to_page(pfn);
 }
 
+struct folio *vm_normal_folio(struct vm_area_struct *vma, unsigned long addr,
+			    pte_t pte)
+{
+	struct page *page = vm_normal_page(vma, addr, pte);
+
+	if (page)
+		return page_folio(page);
+	return NULL;
+}
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
 				pmd_t pmd)
-- 
2.38.1