[PATCH 4/4] pgtable: Remove uses of page->lru

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

Use ptdesc->pt_list instead of page->lru.  These are the same bits for
now, but will be different when ptdesc is allocated separately.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/mm_types.h |  1 +
 mm/pgtable-generic.c     | 24 +++++++++++++++---------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index a0f4bd6099cc..5e08c4a41777 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -602,6 +602,7 @@ struct ptdesc {
 TABLE_MATCH(flags, pt_flags);
 TABLE_MATCH(compound_head, pt_list);
 TABLE_MATCH(compound_head, _pt_pad_1);
+TABLE_MATCH(lru, pt_list);
 TABLE_MATCH(mapping, __page_mapping);
 TABLE_MATCH(__folio_index, pt_index);
 TABLE_MATCH(rcu_head, pt_rcu_head);
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 597049e21ac1..a3990c04b31e 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -166,13 +166,14 @@ pud_t pudp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 				pgtable_t pgtable)
 {
+	struct ptdesc *ptdesc = page_ptdesc(pgtable);
 	assert_spin_locked(pmd_lockptr(mm, pmdp));
 
 	/* FIFO */
 	if (!pmd_huge_pte(mm, pmdp))
-		INIT_LIST_HEAD(&pgtable->lru);
+		INIT_LIST_HEAD(&ptdesc->pt_list);
 	else
-		list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru);
+		list_add(&ptdesc->pt_list, &page_ptdesc(pmd_huge_pte(mm, pmdp))->pt_list);
 	pmd_huge_pte(mm, pmdp) = pgtable;
 }
 #endif
@@ -181,17 +182,22 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 /* no "address" argument so destroys page coloring of some arch */
 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 {
-	pgtable_t pgtable;
+	struct ptdesc *ptdesc, *next;
+	struct page *page;
 
 	assert_spin_locked(pmd_lockptr(mm, pmdp));
 
 	/* FIFO */
-	pgtable = pmd_huge_pte(mm, pmdp);
-	pmd_huge_pte(mm, pmdp) = list_first_entry_or_null(&pgtable->lru,
-							  struct page, lru);
-	if (pmd_huge_pte(mm, pmdp))
-		list_del(&pgtable->lru);
-	return pgtable;
+	page = pmd_huge_pte(mm, pmdp);
+	ptdesc = page_ptdesc(page);
+	next = list_first_entry_or_null(&ptdesc->pt_list, struct ptdesc, pt_list);
+	if (next) {
+		pmd_huge_pte(mm, pmdp) = ptdesc_page(next);
+		list_del(&ptdesc->pt_list);
+	} else {
+		pmd_huge_pte(mm, pmdp) = NULL;
+	}
+	return page;
 }
 #endif
 
-- 
2.47.2