From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon, 8 Sep 2025 17:11:00 +0000 (+0100)
Subject: ptdesc: convert __page_flags to pt_flags
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b25f6227965ad5f04a0aa0accd9bada89b86223a;p=users%2Fjedix%2Flinux-maple.git

ptdesc: convert __page_flags to pt_flags

Patch series "Some ptdesc cleanups".

The first two patches here are preparation for splitting struct ptdesc
from struct page and struct folio.  I think their only dependency is on
the memdesc_flags_t patches from August which is in mm-new.  The third
patch is just something I noticed while working on the code.


This patch (of 3):

Use the new memdesc_flags_t type to show that these are the same bits as
page/folio/slab and thesefore have the zone/node/section information in
them.  Remove a use of ptdesc_folio() by converting
pagetable_is_reserved() to use test_bit() directly.

Link: https://lkml.kernel.org/r/20250908171104.2409217-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20250908171104.2409217-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a6bfa46937a8..8dd71392eba7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2934,6 +2934,11 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
 }
 #endif /* CONFIG_MMU */
 
+enum pt_flags {
+	PT_reserved = PG_reserved,
+	/* High bits are used for zone/node/section */
+};
+
 static inline struct ptdesc *virt_to_ptdesc(const void *x)
 {
 	return page_ptdesc(virt_to_page(x));
@@ -2951,7 +2956,7 @@ static inline void *ptdesc_address(const struct ptdesc *pt)
 
 static inline bool pagetable_is_reserved(struct ptdesc *pt)
 {
-	return folio_test_reserved(ptdesc_folio(pt));
+	return test_bit(PT_reserved, &pt->pt_flags.f);
 }
 
 /**
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index cf759fe08bb3..3dbdddb83c02 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -524,7 +524,7 @@ FOLIO_MATCH(compound_head, _head_3);
 
 /**
  * struct ptdesc -    Memory descriptor for page tables.
- * @__page_flags:     Same as page flags. Powerpc only.
+ * @pt_flags: enum pt_flags plus zone/node/section.
  * @pt_rcu_head:      For freeing page table pages.
  * @pt_list:          List of used page tables. Used for s390 gmap shadow pages
  *                    (which are not linked into the user page tables) and x86
@@ -546,7 +546,7 @@ FOLIO_MATCH(compound_head, _head_3);
  * understanding of the issues.
  */
 struct ptdesc {
-	unsigned long __page_flags;
+	memdesc_flags_t pt_flags;
 
 	union {
 		struct rcu_head pt_rcu_head;
@@ -584,7 +584,7 @@ struct ptdesc {
 
 #define TABLE_MATCH(pg, pt)						\
 	static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt))
-TABLE_MATCH(flags, __page_flags);
+TABLE_MATCH(flags, pt_flags);
 TABLE_MATCH(compound_head, pt_list);
 TABLE_MATCH(compound_head, _pt_pad_1);
 TABLE_MATCH(mapping, __page_mapping);