[RFC PATCH 17/18] mm: convert vmf.prealloc_pte to struct ptdesc pointer

[alexs@xxxxxxxxxx]

From: Alex Shi <alexs@xxxxxxxxxx>

vmfs.prealloc_pte is a pointer to page table memory, so converter it to
struct ptdesc pointer.

Signed-off-by: Alex Shi <alexs@xxxxxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: Matthew Wilcox  <willy@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
 include/linux/mm.h |  2 +-
 mm/filemap.c       |  2 +-
 mm/memory.c        | 12 ++++++------
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7424f964dff3..749d6dd311fa 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -567,7 +567,7 @@ struct vm_fault {
 					 * Protects pte page table if 'pte'
 					 * is not NULL, otherwise pmd.
 					 */
-	pgtable_t prealloc_pte;		/* Pre-allocated pte page table.
+	struct ptdesc *prealloc_pte;	/* Pre-allocated pte page table.
 					 * vm_ops->map_pages() sets up a page
 					 * table from atomic context.
 					 * do_fault_around() pre-allocates
diff --git a/mm/filemap.c b/mm/filemap.c
index 3708ef71182e..d62150418b91 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3453,7 +3453,7 @@ static bool filemap_map_pmd(struct vm_fault *vmf, struct folio *folio,
 	}
 
 	if (pmd_none(*vmf->pmd) && vmf->prealloc_pte)
-		pmd_install(mm, vmf->pmd, (struct ptdesc **)&vmf->prealloc_pte);
+		pmd_install(mm, vmf->pmd, &vmf->prealloc_pte);
 
 	return false;
 }
diff --git a/mm/memory.c b/mm/memory.c
index 79685600d23f..1a5fb17ab045 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4648,7 +4648,7 @@ static vm_fault_t __do_fault(struct vm_fault *vmf)
 	 *				# flush A, B to clear the writeback
 	 */
 	if (pmd_none(*vmf->pmd) && !vmf->prealloc_pte) {
-		vmf->prealloc_pte = ptdesc_page(pte_alloc_one(vma->vm_mm));
+		vmf->prealloc_pte = pte_alloc_one(vma->vm_mm);
 		if (!vmf->prealloc_pte)
 			return VM_FAULT_OOM;
 	}
@@ -4687,7 +4687,7 @@ static void deposit_prealloc_pte(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
 
-	pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, page_ptdesc(vmf->prealloc_pte));
+	pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, vmf->prealloc_pte);
 	/*
 	 * We are going to consume the prealloc table,
 	 * count that as nr_ptes.
@@ -4726,7 +4726,7 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
 	 * related to pte entry. Use the preallocated table for that.
 	 */
 	if (arch_needs_pgtable_deposit() && !vmf->prealloc_pte) {
-		vmf->prealloc_pte = ptdesc_page(pte_alloc_one(vma->vm_mm));
+		vmf->prealloc_pte = pte_alloc_one(vma->vm_mm);
 		if (!vmf->prealloc_pte)
 			return VM_FAULT_OOM;
 	}
@@ -4868,7 +4868,7 @@ vm_fault_t finish_fault(struct vm_fault *vmf)
 		}
 
 		if (vmf->prealloc_pte)
-			pmd_install(vma->vm_mm, vmf->pmd, (struct ptdesc **)&vmf->prealloc_pte);
+			pmd_install(vma->vm_mm, vmf->pmd, &vmf->prealloc_pte);
 		else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd)))
 			return VM_FAULT_OOM;
 	}
@@ -5011,7 +5011,7 @@ static vm_fault_t do_fault_around(struct vm_fault *vmf)
 		      pte_off + vma_pages(vmf->vma) - vma_off) - 1;
 
 	if (pmd_none(*vmf->pmd)) {
-		vmf->prealloc_pte = ptdesc_page(pte_alloc_one(vmf->vma->vm_mm));
+		vmf->prealloc_pte = pte_alloc_one(vmf->vma->vm_mm);
 		if (!vmf->prealloc_pte)
 			return VM_FAULT_OOM;
 	}
@@ -5197,7 +5197,7 @@ static vm_fault_t do_fault(struct vm_fault *vmf)
 
 	/* preallocated pagetable is unused: free it */
 	if (vmf->prealloc_pte) {
-		pte_free(vm_mm, page_ptdesc(vmf->prealloc_pte));
+		pte_free(vm_mm, vmf->prealloc_pte);
 		vmf->prealloc_pte = NULL;
 	}
 	return ret;
-- 
2.43.0