Commit 2db30816 authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

mm: introduce and use vm_normal_page_pud() 

Let's introduce vm_normal_page_pud(), which ends up being fairly simple
because of our new common helpers and there not being a PUD-sized zero
folio.

Use vm_normal_page_pud() in folio_walk_start() to resolve a TODO,
structuring the code like the other (pmd/pte) cases.  Defer introducing
vm_normal_folio_pud() until really used.

Note that we can so far get PUDs with hugetlb, daxfs and PFNMAP entries.

Link: https://lkml.kernel.org/r/20250811112631.759341-11-david@redhat.com


Reviewed-by: default avatarWei Yang <richard.weiyang@gmail.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Juegren Gross <jgross@suse.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent af385388

include/linux/mm.h

+2 −0
Original line number Diff line number Diff line
@@ -2360,6 +2360,8 @@ struct folio *vm_normal_folio_pmd(struct vm_area_struct *vma, 
				  unsigned long addr, pmd_t pmd);

struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,

				pmd_t pmd);

struct page *vm_normal_page_pud(struct vm_area_struct *vma, unsigned long addr,

		pud_t pud);



void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,

		  unsigned long size);

mm/memory.c

+19 −0
Original line number Diff line number Diff line
@@ -809,6 +809,25 @@ struct folio *vm_normal_folio_pmd(struct vm_area_struct *vma, 
		return page_folio(page);

	return NULL;

}



/**

 * vm_normal_page_pud() - Get the "struct page" associated with a PUD

 * @vma: The VMA mapping the @pud.

 * @addr: The address where the @pud is mapped.

 * @pud: The PUD.

 *

 * Get the "struct page" associated with a PUD. See __vm_normal_page()

 * for details on "normal" and "special" mappings.

 *

 * Return: Returns the "struct page" if this is a "normal" mapping. Returns

 *	   NULL if this is a "special" mapping.

 */

struct page *vm_normal_page_pud(struct vm_area_struct *vma,

		unsigned long addr, pud_t pud)

{

	return __vm_normal_page(vma, addr, pud_pfn(pud), pud_special(pud),

				pud_val(pud), PGTABLE_LEVEL_PUD);

}

#endif



/**

mm/pagewalk.c

+10 −10
Original line number Diff line number Diff line
@@ -902,23 +902,23 @@ struct folio *folio_walk_start(struct folio_walk *fw, 
		fw->pudp = pudp;

		fw->pud = pud;



		/*

		 * TODO: FW_MIGRATION support for PUD migration entries

		 * once there are relevant users.

		 */

		if (!pud_present(pud) || pud_special(pud)) {

		if (pud_none(pud)) {

			spin_unlock(ptl);

			goto not_found;

		} else if (!pud_leaf(pud)) {

		} else if (pud_present(pud) && !pud_leaf(pud)) {

			spin_unlock(ptl);

			goto pmd_table;

		} else if (pud_present(pud)) {

			page = vm_normal_page_pud(vma, addr, pud);

			if (page)

				goto found;

		}

		/*

		 * TODO: vm_normal_page_pud() will be handy once we want to

		 * support PUD mappings in VM_PFNMAP|VM_MIXEDMAP VMAs.

		 * TODO: FW_MIGRATION support for PUD migration entries

		 * once there are relevant users.

		 */

		page = pud_page(pud);

		goto found;

		spin_unlock(ptl);

		goto not_found;

	}



pmd_table: