mm: introduce memdesc_flags_t

Patch series "Add and use memdesc_flags_t".

At some point struct page will be separated from struct slab and struct
folio. This is a step towards that by introducing a type for the 'flags'
word of all three structures. This gives us a certain amount of type
safety by establishing that some of these unsigned longs are different
from other unsigned longs in that they contain things like node ID,
section number and zone number in the upper bits. That lets us have
functions that can be easily called by anyone who has a slab, folio or
page (but not easily by anyone else) to get the node or zone.

There's going to be some unusual merge problems with this as some odd bits
of the kernel decide they want to print out the flags value or something
similar by writing page->flags and now they'll need to write page->flags.f
instead. That's most of the churn here. Maybe we should be removing
these things from the debug output?


This patch (of 11):

Wrap the unsigned long flags in a typedef. In upcoming patches, this will
provide a strong hint that you can't just pass a random unsigned long to
functions which take this as an argument.

[[e-mail]: s/flags/flags.f/ in several architectures]
Link: https://lkml.kernel.org/r/[e-mail]
[[e-mail]: mips: fix compilation error]
Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=[e-mail]/
Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Matthew Wilcox (Oracle) <[e-mail]>
Signed-off-by: Matthew Wilcox (Oracle) <[e-mail]>
Acked-by: Zi Yan <[e-mail]>
Cc: Shakeel Butt <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

arch/arc/mm/cache.c

···
 
 void flush_dcache_folio(struct folio *folio)
 {
-	clear_bit(PG_dc_clean, &folio->flags);
+	clear_bit(PG_dc_clean, &folio->flags.f);
 	return;
 }
 EXPORT_SYMBOL(flush_dcache_folio);
···
 
 	copy_page(kto, kfrom);
 
-	clear_bit(PG_dc_clean, &dst->flags);
-	clear_bit(PG_dc_clean, &src->flags);
+	clear_bit(PG_dc_clean, &dst->flags.f);
+	clear_bit(PG_dc_clean, &src->flags.f);
 
 	kunmap_atomic(kto);
 	kunmap_atomic(kfrom);
···
 {
 	struct folio *folio = page_folio(page);
 	clear_page(to);
-	clear_bit(PG_dc_clean, &folio->flags);
+	clear_bit(PG_dc_clean, &folio->flags.f);
 }
 EXPORT_SYMBOL(clear_user_page);
 

arch/arc/mm/tlb.c

···
 	 */
 	if (vma->vm_flags & VM_EXEC) {
 		struct folio *folio = page_folio(page);
-		int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags);
+		int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags.f);
 		if (dirty) {
 			unsigned long offset = offset_in_folio(folio, paddr);
 			nr = folio_nr_pages(folio);

arch/arm/include/asm/hugetlb.h

···
 
 static inline void arch_clear_hugetlb_flags(struct folio *folio)
 {
-	clear_bit(PG_dcache_clean, &folio->flags);
+	clear_bit(PG_dcache_clean, &folio->flags.f);
 }
 #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
 

arch/arm/mm/copypage-v4mc.c

···
 	struct folio *src = page_folio(from);
 	void *kto = kmap_atomic(to);
 
-	if (!test_and_set_bit(PG_dcache_clean, &src->flags))
+	if (!test_and_set_bit(PG_dcache_clean, &src->flags.f))
 		__flush_dcache_folio(folio_flush_mapping(src), src);
 
 	raw_spin_lock(&minicache_lock);

arch/arm/mm/copypage-v6.c

···
 	unsigned int offset = CACHE_COLOUR(vaddr);
 	unsigned long kfrom, kto;
 
-	if (!test_and_set_bit(PG_dcache_clean, &src->flags))
+	if (!test_and_set_bit(PG_dcache_clean, &src->flags.f))
 		__flush_dcache_folio(folio_flush_mapping(src), src);
 
 	/* FIXME: not highmem safe */

arch/arm/mm/copypage-xscale.c

···
 	struct folio *src = page_folio(from);
 	void *kto = kmap_atomic(to);
 
-	if (!test_and_set_bit(PG_dcache_clean, &src->flags))
+	if (!test_and_set_bit(PG_dcache_clean, &src->flags.f))
 		__flush_dcache_folio(folio_flush_mapping(src), src);
 
 	raw_spin_lock(&minicache_lock);

arch/arm/mm/dma-mapping.c

···
 			if (size < sz)
 				break;
 			if (!offset)
-				set_bit(PG_dcache_clean, &folio->flags);
+				set_bit(PG_dcache_clean, &folio->flags.f);
 			offset = 0;
 			size -= sz;
 			if (!size)

arch/arm/mm/fault-armv.c

···
 
 	folio = page_folio(pfn_to_page(pfn));
 	mapping = folio_flush_mapping(folio);
-	if (!test_and_set_bit(PG_dcache_clean, &folio->flags))
+	if (!test_and_set_bit(PG_dcache_clean, &folio->flags.f))
 		__flush_dcache_folio(mapping, folio);
 	if (mapping) {
 		if (cache_is_vivt())

arch/arm/mm/flush.c

···
 	else
 		mapping = NULL;
 
-	if (!test_and_set_bit(PG_dcache_clean, &folio->flags))
+	if (!test_and_set_bit(PG_dcache_clean, &folio->flags.f))
 		__flush_dcache_folio(mapping, folio);
 
 	if (pte_exec(pteval))
···
 		return;
 
 	if (!cache_ops_need_broadcast() && cache_is_vipt_nonaliasing()) {
-		if (test_bit(PG_dcache_clean, &folio->flags))
-			clear_bit(PG_dcache_clean, &folio->flags);
+		if (test_bit(PG_dcache_clean, &folio->flags.f))
+			clear_bit(PG_dcache_clean, &folio->flags.f);
 		return;
 	}
 
···
 
 	if (!cache_ops_need_broadcast() &&
 	    mapping && !folio_mapped(folio))
-		clear_bit(PG_dcache_clean, &folio->flags);
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 	else {
 		__flush_dcache_folio(mapping, folio);
 		if (mapping && cache_is_vivt())
 			__flush_dcache_aliases(mapping, folio);
 		else if (mapping)
 			__flush_icache_all();
-		set_bit(PG_dcache_clean, &folio->flags);
+		set_bit(PG_dcache_clean, &folio->flags.f);
 	}
 }
 EXPORT_SYMBOL(flush_dcache_folio);

arch/arm64/include/asm/hugetlb.h

···
 
 static inline void arch_clear_hugetlb_flags(struct folio *folio)
 {
-	clear_bit(PG_dcache_clean, &folio->flags);
+	clear_bit(PG_dcache_clean, &folio->flags.f);
 
 #ifdef CONFIG_ARM64_MTE
 	if (system_supports_mte()) {
-		clear_bit(PG_mte_tagged, &folio->flags);
-		clear_bit(PG_mte_lock, &folio->flags);
+		clear_bit(PG_mte_tagged, &folio->flags.f);
+		clear_bit(PG_mte_lock, &folio->flags.f);
 	}
 #endif
 }

arch/arm64/include/asm/mte.h

···
 	 * before the page flags update.
 	 */
 	smp_wmb();
-	set_bit(PG_mte_tagged, &page->flags);
+	set_bit(PG_mte_tagged, &page->flags.f);
 }
 
 static inline bool page_mte_tagged(struct page *page)
 {
-	bool ret = test_bit(PG_mte_tagged, &page->flags);
+	bool ret = test_bit(PG_mte_tagged, &page->flags.f);
 
 	VM_WARN_ON_ONCE(folio_test_hugetlb(page_folio(page)));
 
···
 {
 	VM_WARN_ON_ONCE(folio_test_hugetlb(page_folio(page)));
 
-	if (!test_and_set_bit(PG_mte_lock, &page->flags))
+	if (!test_and_set_bit(PG_mte_lock, &page->flags.f))
 		return true;
 
 	/*
···
 	 * already. Check if the PG_mte_tagged flag has been set or wait
 	 * otherwise.
 	 */
-	smp_cond_load_acquire(&page->flags, VAL & (1UL << PG_mte_tagged));
+	smp_cond_load_acquire(&page->flags.f, VAL & (1UL << PG_mte_tagged));
 
 	return false;
 }
···
 	 * before the folio flags update.
 	 */
 	smp_wmb();
-	set_bit(PG_mte_tagged, &folio->flags);
+	set_bit(PG_mte_tagged, &folio->flags.f);
 
 }
 
 static inline bool folio_test_hugetlb_mte_tagged(struct folio *folio)
 {
-	bool ret = test_bit(PG_mte_tagged, &folio->flags);
+	bool ret = test_bit(PG_mte_tagged, &folio->flags.f);
 
 	VM_WARN_ON_ONCE(!folio_test_hugetlb(folio));
 
···
 {
 	VM_WARN_ON_ONCE(!folio_test_hugetlb(folio));
 
-	if (!test_and_set_bit(PG_mte_lock, &folio->flags))
+	if (!test_and_set_bit(PG_mte_lock, &folio->flags.f))
 		return true;
 
 	/*
···
 	 * already. Check if the PG_mte_tagged flag has been set or wait
 	 * otherwise.
 	 */
-	smp_cond_load_acquire(&folio->flags, VAL & (1UL << PG_mte_tagged));
+	smp_cond_load_acquire(&folio->flags.f, VAL & (1UL << PG_mte_tagged));
 
 	return false;
 }

arch/arm64/mm/flush.c

···
 {
 	struct folio *folio = page_folio(pte_page(pte));
 
-	if (!test_bit(PG_dcache_clean, &folio->flags)) {
+	if (!test_bit(PG_dcache_clean, &folio->flags.f)) {
 		sync_icache_aliases((unsigned long)folio_address(folio),
 				    (unsigned long)folio_address(folio) +
 					    folio_size(folio));
-		set_bit(PG_dcache_clean, &folio->flags);
+		set_bit(PG_dcache_clean, &folio->flags.f);
 	}
 }
 EXPORT_SYMBOL_GPL(__sync_icache_dcache);
···
  */
 void flush_dcache_folio(struct folio *folio)
 {
-	if (test_bit(PG_dcache_clean, &folio->flags))
-		clear_bit(PG_dcache_clean, &folio->flags);
+	if (test_bit(PG_dcache_clean, &folio->flags.f))
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 }
 EXPORT_SYMBOL(flush_dcache_folio);
 

arch/csky/abiv1/cacheflush.c

···
 	mapping = folio_flush_mapping(folio);
 
 	if (mapping && !folio_mapped(folio))
-		clear_bit(PG_dcache_clean, &folio->flags);
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 	else {
 		dcache_wbinv_all();
 		if (mapping)
 			icache_inv_all();
-		set_bit(PG_dcache_clean, &folio->flags);
+		set_bit(PG_dcache_clean, &folio->flags.f);
 	}
 }
 EXPORT_SYMBOL(flush_dcache_folio);
···
 		return;
 
 	folio = page_folio(pfn_to_page(pfn));
-	if (!test_and_set_bit(PG_dcache_clean, &folio->flags))
+	if (!test_and_set_bit(PG_dcache_clean, &folio->flags.f))
 		dcache_wbinv_all();
 
 	if (folio_flush_mapping(folio)) {

arch/mips/include/asm/cacheflush.h

···
 #define PG_dcache_dirty			PG_arch_1
 
 #define folio_test_dcache_dirty(folio)		\
-	test_bit(PG_dcache_dirty, &(folio)->flags)
+	test_bit(PG_dcache_dirty, &(folio)->flags.f)
 #define folio_set_dcache_dirty(folio)	\
-	set_bit(PG_dcache_dirty, &(folio)->flags)
+	set_bit(PG_dcache_dirty, &(folio)->flags.f)
 #define folio_clear_dcache_dirty(folio)	\
-	clear_bit(PG_dcache_dirty, &(folio)->flags)
+	clear_bit(PG_dcache_dirty, &(folio)->flags.f)
 
 extern void (*flush_cache_all)(void);
 extern void (*__flush_cache_all)(void);

arch/nios2/mm/cacheflush.c

···
 
 	/* Flush this page if there are aliases. */
 	if (mapping && !mapping_mapped(mapping)) {
-		clear_bit(PG_dcache_clean, &folio->flags);
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 	} else {
 		__flush_dcache_folio(folio);
 		if (mapping) {
···
 			flush_aliases(mapping, folio);
 			flush_icache_range(start, start + folio_size(folio));
 		}
-		set_bit(PG_dcache_clean, &folio->flags);
+		set_bit(PG_dcache_clean, &folio->flags.f);
 	}
 }
 EXPORT_SYMBOL(flush_dcache_folio);
···
 		return;
 
 	folio = page_folio(pfn_to_page(pfn));
-	if (!test_and_set_bit(PG_dcache_clean, &folio->flags))
+	if (!test_and_set_bit(PG_dcache_clean, &folio->flags.f))
 		__flush_dcache_folio(folio);
 
 	mapping = folio_flush_mapping(folio);

arch/openrisc/include/asm/cacheflush.h

···
 
 static inline void flush_dcache_folio(struct folio *folio)
 {
-	clear_bit(PG_dc_clean, &folio->flags);
+	clear_bit(PG_dc_clean, &folio->flags.f);
 }
 #define flush_dcache_folio flush_dcache_folio
 

arch/openrisc/mm/cache.c

···
 {
 	unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
 	struct folio *folio = page_folio(pfn_to_page(pfn));
-	int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags);
+	int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags.f);
 
 	/*
 	 * Since icaches do not snoop for updated data on OpenRISC, we

arch/parisc/kernel/cache.c

···
 	pfn = folio_pfn(folio);
 	nr = folio_nr_pages(folio);
 	if (folio_flush_mapping(folio) &&
-	    test_bit(PG_dcache_dirty, &folio->flags)) {
+	    test_bit(PG_dcache_dirty, &folio->flags.f)) {
 		while (nr--)
 			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
-		clear_bit(PG_dcache_dirty, &folio->flags);
+		clear_bit(PG_dcache_dirty, &folio->flags.f);
 	} else if (parisc_requires_coherency())
 		while (nr--)
 			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
···
 	pgoff_t pgoff;
 
 	if (mapping && !mapping_mapped(mapping)) {
-		set_bit(PG_dcache_dirty, &folio->flags);
+		set_bit(PG_dcache_dirty, &folio->flags.f);
 		return;
 	}
 

arch/powerpc/include/asm/cacheflush.h

···
 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 		return;
 	/* avoid an atomic op if possible */
-	if (test_bit(PG_dcache_clean, &folio->flags))
-		clear_bit(PG_dcache_clean, &folio->flags);
+	if (test_bit(PG_dcache_clean, &folio->flags.f))
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 }
 #define flush_dcache_folio flush_dcache_folio
 

arch/powerpc/include/asm/kvm_ppc.h

···
 
 	/* Clear i-cache for new pages */
 	folio = page_folio(pfn_to_page(pfn));
-	if (!test_bit(PG_dcache_clean, &folio->flags)) {
+	if (!test_bit(PG_dcache_clean, &folio->flags.f)) {
 		flush_dcache_icache_folio(folio);
-		set_bit(PG_dcache_clean, &folio->flags);
+		set_bit(PG_dcache_clean, &folio->flags.f);
 	}
 }
 

arch/powerpc/mm/book3s64/hash_utils.c

···
 	folio = page_folio(pte_page(pte));
 
 	/* page is dirty */
-	if (!test_bit(PG_dcache_clean, &folio->flags) &&
+	if (!test_bit(PG_dcache_clean, &folio->flags.f) &&
 	    !folio_test_reserved(folio)) {
 		if (trap == INTERRUPT_INST_STORAGE) {
 			flush_dcache_icache_folio(folio);
-			set_bit(PG_dcache_clean, &folio->flags);
+			set_bit(PG_dcache_clean, &folio->flags.f);
 		} else
 			pp |= HPTE_R_N;
 	}

arch/powerpc/mm/pgtable.c

···
 		struct folio *folio = maybe_pte_to_folio(pte);
 		if (!folio)
 			return pte;
-		if (!test_bit(PG_dcache_clean, &folio->flags)) {
+		if (!test_bit(PG_dcache_clean, &folio->flags.f)) {
 			flush_dcache_icache_folio(folio);
-			set_bit(PG_dcache_clean, &folio->flags);
+			set_bit(PG_dcache_clean, &folio->flags.f);
 		}
 	}
 	return pte;
···
 		return pte;
 
 	/* If the page clean, we move on */
-	if (test_bit(PG_dcache_clean, &folio->flags))
+	if (test_bit(PG_dcache_clean, &folio->flags.f))
 		return pte;
 
 	/* If it's an exec fault, we flush the cache and make it clean */
 	if (is_exec_fault()) {
 		flush_dcache_icache_folio(folio);
-		set_bit(PG_dcache_clean, &folio->flags);
+		set_bit(PG_dcache_clean, &folio->flags.f);
 		return pte;
 	}
 
···
 		goto bail;
 
 	/* If the page is already clean, we move on */
-	if (test_bit(PG_dcache_clean, &folio->flags))
+	if (test_bit(PG_dcache_clean, &folio->flags.f))
 		goto bail;
 
 	/* Clean the page and set PG_dcache_clean */
 	flush_dcache_icache_folio(folio);
-	set_bit(PG_dcache_clean, &folio->flags);
+	set_bit(PG_dcache_clean, &folio->flags.f);
 
  bail:
 	return pte_mkexec(pte);

arch/riscv/include/asm/cacheflush.h

···
 
 static inline void flush_dcache_folio(struct folio *folio)
 {
-	if (test_bit(PG_dcache_clean, &folio->flags))
-		clear_bit(PG_dcache_clean, &folio->flags);
+	if (test_bit(PG_dcache_clean, &folio->flags.f))
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 }
 #define flush_dcache_folio flush_dcache_folio
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1

arch/riscv/include/asm/hugetlb.h

···
 
 static inline void arch_clear_hugetlb_flags(struct folio *folio)
 {
-	clear_bit(PG_dcache_clean, &folio->flags);
+	clear_bit(PG_dcache_clean, &folio->flags.f);
 }
 #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
 

arch/riscv/mm/cacheflush.c

···
 {
 	struct folio *folio = page_folio(pte_page(pte));
 
-	if (!test_bit(PG_dcache_clean, &folio->flags)) {
+	if (!test_bit(PG_dcache_clean, &folio->flags.f)) {
 		flush_icache_mm(mm, false);
-		set_bit(PG_dcache_clean, &folio->flags);
+		set_bit(PG_dcache_clean, &folio->flags.f);
 	}
 }
 #endif /* CONFIG_MMU */

arch/s390/include/asm/hugetlb.h

···
 
 static inline void arch_clear_hugetlb_flags(struct folio *folio)
 {
-	clear_bit(PG_arch_1, &folio->flags);
+	clear_bit(PG_arch_1, &folio->flags.f);
 }
 #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
 

arch/s390/kernel/uv.c

···
 	folio_get(folio);
 	rc = uv_destroy(folio_to_phys(folio));
 	if (!rc)
-		clear_bit(PG_arch_1, &folio->flags);
+		clear_bit(PG_arch_1, &folio->flags.f);
 	folio_put(folio);
 	return rc;
 }
···
 	folio_get(folio);
 	rc = uv_convert_from_secure(folio_to_phys(folio));
 	if (!rc)
-		clear_bit(PG_arch_1, &folio->flags);
+		clear_bit(PG_arch_1, &folio->flags.f);
 	folio_put(folio);
 	return rc;
 }
···
 	expected = expected_folio_refs(folio) + 1;
 	if (!folio_ref_freeze(folio, expected))
 		return -EBUSY;
-	set_bit(PG_arch_1, &folio->flags);
+	set_bit(PG_arch_1, &folio->flags.f);
 	/*
 	 * If the UVC does not succeed or fail immediately, we don't want to
 	 * loop for long, or we might get stall notifications.
···
 	 *    convert_to_secure.
 	 * As secure pages are never large folios, both variants can co-exists.
 	 */
-	if (!test_bit(PG_arch_1, &folio->flags))
+	if (!test_bit(PG_arch_1, &folio->flags.f))
 		return 0;
 
 	rc = uv_pin_shared(folio_to_phys(folio));
 	if (!rc) {
-		clear_bit(PG_arch_1, &folio->flags);
+		clear_bit(PG_arch_1, &folio->flags.f);
 		return 0;
 	}
 
 	rc = uv_convert_from_secure(folio_to_phys(folio));
 	if (!rc) {
-		clear_bit(PG_arch_1, &folio->flags);
+		clear_bit(PG_arch_1, &folio->flags.f);
 		return 0;
 	}
 

arch/s390/mm/gmap.c

···
 	start = pmd_val(*pmd) & HPAGE_MASK;
 	end = start + HPAGE_SIZE;
 	__storage_key_init_range(start, end);
-	set_bit(PG_arch_1, &folio->flags);
+	set_bit(PG_arch_1, &folio->flags.f);
 	cond_resched();
 	return 0;
 }

arch/s390/mm/hugetlbpage.c

···
 		paddr = rste & PMD_MASK;
 	}
 
-	if (!test_and_set_bit(PG_arch_1, &folio->flags))
+	if (!test_and_set_bit(PG_arch_1, &folio->flags.f))
 		__storage_key_init_range(paddr, paddr + size);
 }
 

arch/sh/include/asm/hugetlb.h

···
 
 static inline void arch_clear_hugetlb_flags(struct folio *folio)
 {
-	clear_bit(PG_dcache_clean, &folio->flags);
+	clear_bit(PG_dcache_clean, &folio->flags.f);
 }
 #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
 

arch/sh/mm/cache-sh4.c

···
 	struct address_space *mapping = folio_flush_mapping(folio);
 
 	if (mapping && !mapping_mapped(mapping))
-		clear_bit(PG_dcache_clean, &folio->flags);
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 	else
 #endif
 	{

arch/sh/mm/cache-sh7705.c

···
 	struct address_space *mapping = folio_flush_mapping(folio);
 
 	if (mapping && !mapping_mapped(mapping))
-		clear_bit(PG_dcache_clean, &folio->flags);
+		clear_bit(PG_dcache_clean, &folio->flags.f);
 	else {
 		unsigned long pfn = folio_pfn(folio);
 		unsigned int i, nr = folio_nr_pages(folio);

arch/sh/mm/cache.c

···
 	struct folio *folio = page_folio(page);
 
 	if (boot_cpu_data.dcache.n_aliases && folio_mapped(folio) &&
-	    test_bit(PG_dcache_clean, &folio->flags)) {
+	    test_bit(PG_dcache_clean, &folio->flags.f)) {
 		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 		memcpy(vto, src, len);
 		kunmap_coherent(vto);
 	} else {
 		memcpy(dst, src, len);
 		if (boot_cpu_data.dcache.n_aliases)
-			clear_bit(PG_dcache_clean, &folio->flags);
+			clear_bit(PG_dcache_clean, &folio->flags.f);
 	}
 
 	if (vma->vm_flags & VM_EXEC)
···
 	struct folio *folio = page_folio(page);
 
 	if (boot_cpu_data.dcache.n_aliases && folio_mapped(folio) &&
-	    test_bit(PG_dcache_clean, &folio->flags)) {
+	    test_bit(PG_dcache_clean, &folio->flags.f)) {
 		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 		memcpy(dst, vfrom, len);
 		kunmap_coherent(vfrom);
 	} else {
 		memcpy(dst, src, len);
 		if (boot_cpu_data.dcache.n_aliases)
-			clear_bit(PG_dcache_clean, &folio->flags);
+			clear_bit(PG_dcache_clean, &folio->flags.f);
 	}
 }
 
···
 	vto = kmap_atomic(to);
 
 	if (boot_cpu_data.dcache.n_aliases && folio_mapped(src) &&
-	    test_bit(PG_dcache_clean, &src->flags)) {
+	    test_bit(PG_dcache_clean, &src->flags.f)) {
 		vfrom = kmap_coherent(from, vaddr);
 		copy_page(vto, vfrom);
 		kunmap_coherent(vfrom);
···
 
 	if (pfn_valid(pfn)) {
 		struct folio *folio = page_folio(pfn_to_page(pfn));
-		int dirty = !test_and_set_bit(PG_dcache_clean, &folio->flags);
+		int dirty = !test_and_set_bit(PG_dcache_clean, &folio->flags.f);
 		if (dirty)
 			__flush_purge_region(folio_address(folio),
 						folio_size(folio));
···
 
 	if (pages_do_alias(addr, vmaddr)) {
 		if (boot_cpu_data.dcache.n_aliases && folio_mapped(folio) &&
-		    test_bit(PG_dcache_clean, &folio->flags)) {
+		    test_bit(PG_dcache_clean, &folio->flags.f)) {
 			void *kaddr;
 
 			kaddr = kmap_coherent(page, vmaddr);

arch/sh/mm/kmap.c

···
 	enum fixed_addresses idx;
 	unsigned long vaddr;
 
-	BUG_ON(!test_bit(PG_dcache_clean, &folio->flags));
+	BUG_ON(!test_bit(PG_dcache_clean, &folio->flags.f));
 
 	preempt_disable();
 	pagefault_disable();

arch/sparc/mm/init_64.c

···
 	((1UL<<ilog2(roundup_pow_of_two(NR_CPUS)))-1UL)
 
 #define dcache_dirty_cpu(folio) \
-	(((folio)->flags >> PG_dcache_cpu_shift) & PG_dcache_cpu_mask)
+	(((folio)->flags.f >> PG_dcache_cpu_shift) & PG_dcache_cpu_mask)
 
 static inline void set_dcache_dirty(struct folio *folio, int this_cpu)
 {
···
 			     "bne,pn	%%xcc, 1b\n\t"
 			     " nop"
 			     : /* no outputs */
-			     : "r" (mask), "r" (non_cpu_bits), "r" (&folio->flags)
+			     : "r" (mask), "r" (non_cpu_bits), "r" (&folio->flags.f)
 			     : "g1", "g7");
 }
 
···
 			     " nop\n"
 			     "2:"
 			     : /* no outputs */
-			     : "r" (cpu), "r" (mask), "r" (&folio->flags),
+			     : "r" (cpu), "r" (mask), "r" (&folio->flags.f),
 			       "i" (PG_dcache_cpu_mask),
 			       "i" (PG_dcache_cpu_shift)
 			     : "g1", "g7");
···
 		struct folio *folio = page_folio(page);
 		unsigned long pg_flags;
 
-		pg_flags = folio->flags;
+		pg_flags = folio->flags.f;
 		if (pg_flags & (1UL << PG_dcache_dirty)) {
 			int cpu = ((pg_flags >> PG_dcache_cpu_shift) &
 				   PG_dcache_cpu_mask);
···
 
 	mapping = folio_flush_mapping(folio);
 	if (mapping && !mapping_mapped(mapping)) {
-		bool dirty = test_bit(PG_dcache_dirty, &folio->flags);
+		bool dirty = test_bit(PG_dcache_dirty, &folio->flags.f);
 		if (dirty) {
 			int dirty_cpu = dcache_dirty_cpu(folio);
 

arch/x86/mm/pat/memtype.c

···
 
 static inline enum page_cache_mode get_page_memtype(struct page *pg)
 {
-	unsigned long pg_flags = pg->flags & _PGMT_MASK;
+	unsigned long pg_flags = pg->flags.f & _PGMT_MASK;
 
 	if (pg_flags == _PGMT_WB)
 		return _PAGE_CACHE_MODE_WB;
···
 		break;
 	}
 
-	old_flags = READ_ONCE(pg->flags);
+	old_flags = READ_ONCE(pg->flags.f);
 	do {
 		new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags;
-	} while (!try_cmpxchg(&pg->flags, &old_flags, new_flags));
+	} while (!try_cmpxchg(&pg->flags.f, &old_flags, new_flags));
 }
 #else
 static inline enum page_cache_mode get_page_memtype(struct page *pg)

arch/xtensa/mm/cache.c

···
 	 */
 
 	if (mapping && !mapping_mapped(mapping)) {
-		if (!test_bit(PG_arch_1, &folio->flags))
-			set_bit(PG_arch_1, &folio->flags);
+		if (!test_bit(PG_arch_1, &folio->flags.f))
+			set_bit(PG_arch_1, &folio->flags.f);
 		return;
 
 	} else {
···
 
 #if (DCACHE_WAY_SIZE > PAGE_SIZE)
 
-	if (!folio_test_reserved(folio) && test_bit(PG_arch_1, &folio->flags)) {
+	if (!folio_test_reserved(folio) && test_bit(PG_arch_1, &folio->flags.f)) {
 		unsigned long phys = folio_pfn(folio) * PAGE_SIZE;
 		unsigned long tmp;
 
···
 		}
 		preempt_enable();
 
-		clear_bit(PG_arch_1, &folio->flags);
+		clear_bit(PG_arch_1, &folio->flags.f);
 	}
 #else
-	if (!folio_test_reserved(folio) && !test_bit(PG_arch_1, &folio->flags)
+	if (!folio_test_reserved(folio) && !test_bit(PG_arch_1, &folio->flags.f)
 	    && (vma->vm_flags & VM_EXEC) != 0) {
 		for (i = 0; i < nr; i++) {
 			void *paddr = kmap_local_folio(folio, i * PAGE_SIZE);
···
 			__invalidate_icache_page((unsigned long)paddr);
 			kunmap_local(paddr);
 		}
-		set_bit(PG_arch_1, &folio->flags);
+		set_bit(PG_arch_1, &folio->flags.f);
 	}
 #endif
 }

fs/fuse/dev.c

···
 {
 	if (folio_mapped(folio) ||
 	    folio->mapping != NULL ||
-	    (folio->flags & PAGE_FLAGS_CHECK_AT_PREP &
+	    (folio->flags.f & PAGE_FLAGS_CHECK_AT_PREP &
 	     ~(1 << PG_locked |
 	       1 << PG_referenced |
 	       1 << PG_lru |

fs/gfs2/glops.c

···
 	       "AIL buffer %p: blocknr %llu state 0x%08lx mapping %p page "
 	       "state 0x%lx\n",
 	       bh, (unsigned long long)bh->b_blocknr, bh->b_state,
-	       bh->b_folio->mapping, bh->b_folio->flags);
+	       bh->b_folio->mapping, bh->b_folio->flags.f);
 	fs_err(sdp, "AIL glock %u:%llu mapping %p\n",
 	       gl->gl_name.ln_type, gl->gl_name.ln_number,
 	       gfs2_glock2aspace(gl));

fs/jffs2/file.c

···
 			goto release_sem;
 		}
 	}
-	jffs2_dbg(1, "end write_begin(). folio->flags %lx\n", folio->flags);
+	jffs2_dbg(1, "end write_begin(). folio->flags %lx\n", folio->flags.f);
 
 release_sem:
 	mutex_unlock(&c->alloc_sem);
···
 
 	jffs2_dbg(1, "%s(): ino #%lu, page at 0x%llx, range %d-%d, flags %lx\n",
 		  __func__, inode->i_ino, folio_pos(folio),
-		  start, end, folio->flags);
+		  start, end, folio->flags.f);
 
 	/* We need to avoid deadlock with page_cache_read() in
 	   jffs2_garbage_collect_pass(). So the folio must be

fs/nilfs2/page.c

···
 	printk(KERN_CRIT "NILFS_FOLIO_BUG(%p): cnt=%d index#=%llu flags=0x%lx "
 	       "mapping=%p ino=%lu\n",
 	       folio, folio_ref_count(folio),
-	       (unsigned long long)folio->index, folio->flags, m, ino);
+	       (unsigned long long)folio->index, folio->flags.f, m, ino);
 
 	head = folio_buffers(folio);
 	if (head) {

fs/proc/page.c

···
 	snapshot_page(&ps, page);
 	folio = &ps.folio_snapshot;
 
-	k = folio->flags;
+	k = folio->flags.f;
 	mapping = (unsigned long)folio->mapping;
 	is_anon = mapping & FOLIO_MAPPING_ANON;
 
···
 	if (u & (1 << KPF_HUGE))
 		u |= kpf_copy_bit(k, KPF_HWPOISON,	PG_hwpoison);
 	else
-		u |= kpf_copy_bit(ps.page_snapshot.flags, KPF_HWPOISON, PG_hwpoison);
+		u |= kpf_copy_bit(ps.page_snapshot.flags.f, KPF_HWPOISON, PG_hwpoison);
 #endif
 
 	u |= kpf_copy_bit(k, KPF_RESERVED,	PG_reserved);

fs/ubifs/file.c

···
 	size_t offset = 0;
 
 	dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
-		inode->i_ino, folio->index, i_size, folio->flags);
+		inode->i_ino, folio->index, i_size, folio->flags.f);
 	ubifs_assert(c, !folio_test_checked(folio));
 	ubifs_assert(c, !folio->private);
 
···
 	pgoff_t end_index;
 
 	dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
-		inode->i_ino, folio->index, i_size, folio->flags);
+		inode->i_ino, folio->index, i_size, folio->flags.f);
 
 	end_index = (i_size - 1) >> PAGE_SHIFT;
 	if (!i_size || folio->index > end_index) {
···
 	int err, len = folio_size(folio);
 
 	dbg_gen("ino %lu, pg %lu, pg flags %#lx",
-		inode->i_ino, folio->index, folio->flags);
+		inode->i_ino, folio->index, folio->flags.f);
 	ubifs_assert(c, folio->private != NULL);
 
 	/* Is the folio fully outside @i_size? (truncate in progress) */

include/linux/mm.h

···
 {
 	struct folio *folio = (struct folio *)page;
 
-	if (!test_bit(PG_head, &folio->flags))
+	if (!test_bit(PG_head, &folio->flags.f))
 		return 0;
 	return folio_large_order(folio);
 }
···
  */
 static inline int page_zone_id(struct page *page)
 {
-	return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
+	return (page->flags.f >> ZONEID_PGSHIFT) & ZONEID_MASK;
 }
 
 #ifdef NODE_NOT_IN_PAGE_FLAGS
···
 #else
 static inline int page_to_nid(const struct page *page)
 {
-	return (PF_POISONED_CHECK(page)->flags >> NODES_PGSHIFT) & NODES_MASK;
+	return (PF_POISONED_CHECK(page)->flags.f >> NODES_PGSHIFT) & NODES_MASK;
 }
 #endif
 
···
 #else
 static inline int folio_last_cpupid(struct folio *folio)
 {
-	return (folio->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
+	return (folio->flags.f >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
 }
 
 int folio_xchg_last_cpupid(struct folio *folio, int cpupid);
 
 static inline void page_cpupid_reset_last(struct page *page)
 {
-	page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT;
+	page->flags.f |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT;
 }
 #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
 
···
 	u8 tag = KASAN_TAG_KERNEL;
 
 	if (kasan_enabled()) {
-		tag = (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
+		tag = (page->flags.f >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
 		tag ^= 0xff;
 	}
 
···
 		return;
 
 	tag ^= 0xff;
-	old_flags = READ_ONCE(page->flags);
+	old_flags = READ_ONCE(page->flags.f);
 	do {
 		flags = old_flags;
 		flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT);
 		flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT;
-	} while (unlikely(!try_cmpxchg(&page->flags, &old_flags, flags)));
+	} while (unlikely(!try_cmpxchg(&page->flags.f, &old_flags, flags)));
 }
 
 static inline void page_kasan_tag_reset(struct page *page)
···
 #ifdef SECTION_IN_PAGE_FLAGS
 static inline void set_page_section(struct page *page, unsigned long section)
 {
-	page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
-	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
+	page->flags.f &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
+	page->flags.f |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
 }
 
 static inline unsigned long page_to_section(const struct page *page)
 {
-	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
+	return (page->flags.f >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
 }
 #endif
 
···
 
 static inline void set_page_zone(struct page *page, enum zone_type zone)
 {
-	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
-	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
+	page->flags.f &= ~(ZONES_MASK << ZONES_PGSHIFT);
+	page->flags.f |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
 }
 
 static inline void set_page_node(struct page *page, unsigned long node)
 {
-	page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
-	page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
+	page->flags.f &= ~(NODES_MASK << NODES_PGSHIFT);
+	page->flags.f |= (node & NODES_MASK) << NODES_PGSHIFT;
 }
 
 static inline void set_page_links(struct page *page, enum zone_type zone,
···
 {
 	struct folio *folio = (struct folio *)page;
 
-	if (!test_bit(PG_head, &folio->flags))
+	if (!test_bit(PG_head, &folio->flags.f))
 		return 1;
 	return folio_large_nr_pages(folio);
 }

include/linux/mm_inline.h

···
 
 static inline int folio_lru_refs(struct folio *folio)
 {
-	unsigned long flags = READ_ONCE(folio->flags);
+	unsigned long flags = READ_ONCE(folio->flags.f);
 
 	if (!(flags & BIT(PG_referenced)))
 		return 0;
···
 
 static inline int folio_lru_gen(struct folio *folio)
 {
-	unsigned long flags = READ_ONCE(folio->flags);
+	unsigned long flags = READ_ONCE(folio->flags.f);
 
 	return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
 }
···
 	gen = lru_gen_from_seq(seq);
 	flags = (gen + 1UL) << LRU_GEN_PGOFF;
 	/* see the comment on MIN_NR_GENS about PG_active */
-	set_mask_bits(&folio->flags, LRU_GEN_MASK | BIT(PG_active), flags);
+	set_mask_bits(&folio->flags.f, LRU_GEN_MASK | BIT(PG_active), flags);
 
 	lru_gen_update_size(lruvec, folio, -1, gen);
 	/* for folio_rotate_reclaimable() */
···
 
 	/* for folio_migrate_flags() */
 	flags = !reclaiming && lru_gen_is_active(lruvec, gen) ? BIT(PG_active) : 0;
-	flags = set_mask_bits(&folio->flags, LRU_GEN_MASK, flags);
+	flags = set_mask_bits(&folio->flags.f, LRU_GEN_MASK, flags);
 	gen = ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
 
 	lru_gen_update_size(lruvec, folio, gen, -1);
···
 
 static inline void folio_migrate_refs(struct folio *new, struct folio *old)
 {
-	unsigned long refs = READ_ONCE(old->flags) & LRU_REFS_MASK;
+	unsigned long refs = READ_ONCE(old->flags.f) & LRU_REFS_MASK;
 
-	set_mask_bits(&new->flags, LRU_REFS_MASK, refs);
+	set_mask_bits(&new->flags.f, LRU_REFS_MASK, refs);
 }
 #else /* !CONFIG_LRU_GEN */
 

include/linux/mm_types.h

···
 struct futex_private_hash;
 struct mem_cgroup;
 
+typedef struct {
+	unsigned long f;
+} memdesc_flags_t;
+
 /*
  * Each physical page in the system has a struct page associated with
  * it to keep track of whatever it is we are using the page for at the
···
 #endif
 
 struct page {
-	unsigned long flags;		/* Atomic flags, some possibly
+	memdesc_flags_t flags;		/* Atomic flags, some possibly
 					 * updated asynchronously */
 	/*
 	 * Five words (20/40 bytes) are available in this union.
···
 	union {
 		struct {
 	/* public: */
-			unsigned long flags;
+			memdesc_flags_t flags;
 			union {
 				struct list_head lru;
 	/* private: avoid cluttering the output */

include/linux/mmzone.h

···
 static inline enum zone_type page_zonenum(const struct page *page)
 {
 	ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
-	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
+	return (page->flags.f >> ZONES_PGSHIFT) & ZONES_MASK;
 }
 
 static inline enum zone_type folio_zonenum(const struct folio *folio)

include/linux/page-flags.h

···
 	 * cold cacheline in some cases.
 	 */
 	if (IS_ALIGNED((unsigned long)page, PAGE_SIZE) &&
-	    test_bit(PG_head, &page->flags)) {
+	    test_bit(PG_head, &page->flags.f)) {
 		/*
 		 * We can safely access the field of the @page[1] with PG_head
 		 * because the @page is a compound page composed with at least
···
 
 static __always_inline int PageCompound(const struct page *page)
 {
-	return test_bit(PG_head, &page->flags) ||
+	return test_bit(PG_head, &page->flags.f) ||
 	       READ_ONCE(page->compound_head) & 1;
 }
 
 #define	PAGE_POISON_PATTERN	-1l
 static inline int PagePoisoned(const struct page *page)
 {
-	return READ_ONCE(page->flags) == PAGE_POISON_PATTERN;
+	return READ_ONCE(page->flags.f) == PAGE_POISON_PATTERN;
 }
 
 #ifdef CONFIG_DEBUG_VM
···
 	const struct page *page = &folio->page;
 
 	VM_BUG_ON_PGFLAGS(page->compound_head & 1, page);
-	VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page);
-	return &page[n].flags;
+	VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags.f), page);
+	return &page[n].flags.f;
 }
 
 static unsigned long *folio_flags(struct folio *folio, unsigned n)
···
 	struct page *page = &folio->page;
 
 	VM_BUG_ON_PGFLAGS(page->compound_head & 1, page);
-	VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page);
-	return &page[n].flags;
+	VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags.f), page);
+	return &page[n].flags.f;
 }
 
 /*
···
 #define TESTPAGEFLAG(uname, lname, policy)				\
 FOLIO_TEST_FLAG(lname, FOLIO_##policy)					\
 static __always_inline int Page##uname(const struct page *page)		\
-{ return test_bit(PG_##lname, &policy(page, 0)->flags); }
+{ return test_bit(PG_##lname, &policy(page, 0)->flags.f); }
 
 #define SETPAGEFLAG(uname, lname, policy)				\
 FOLIO_SET_FLAG(lname, FOLIO_##policy)					\
 static __always_inline void SetPage##uname(struct page *page)		\
-{ set_bit(PG_##lname, &policy(page, 1)->flags); }
+{ set_bit(PG_##lname, &policy(page, 1)->flags.f); }
 
 #define CLEARPAGEFLAG(uname, lname, policy)				\
 FOLIO_CLEAR_FLAG(lname, FOLIO_##policy)					\
 static __always_inline void ClearPage##uname(struct page *page)		\
-{ clear_bit(PG_##lname, &policy(page, 1)->flags); }
+{ clear_bit(PG_##lname, &policy(page, 1)->flags.f); }
 
 #define __SETPAGEFLAG(uname, lname, policy)				\
 __FOLIO_SET_FLAG(lname, FOLIO_##policy)					\
 static __always_inline void __SetPage##uname(struct page *page)		\
-{ __set_bit(PG_##lname, &policy(page, 1)->flags); }
+{ __set_bit(PG_##lname, &policy(page, 1)->flags.f); }
 
 #define __CLEARPAGEFLAG(uname, lname, policy)				\
 __FOLIO_CLEAR_FLAG(lname, FOLIO_##policy)				\
 static __always_inline void __ClearPage##uname(struct page *page)	\
-{ __clear_bit(PG_##lname, &policy(page, 1)->flags); }
+{ __clear_bit(PG_##lname, &policy(page, 1)->flags.f); }
 
 #define TESTSETFLAG(uname, lname, policy)				\
 FOLIO_TEST_SET_FLAG(lname, FOLIO_##policy)				\
 static __always_inline int TestSetPage##uname(struct page *page)	\
-{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
+{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags.f); }
 
 #define TESTCLEARFLAG(uname, lname, policy)				\
 FOLIO_TEST_CLEAR_FLAG(lname, FOLIO_##policy)				\
 static __always_inline int TestClearPage##uname(struct page *page)	\
-{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
+{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags.f); }
 
 #define PAGEFLAG(uname, lname, policy)					\
 	TESTPAGEFLAG(uname, lname, policy)				\
···
 static __always_inline int PageHead(const struct page *page)
 {
 	PF_POISONED_CHECK(page);
-	return test_bit(PG_head, &page->flags) && !page_is_fake_head(page);
+	return test_bit(PG_head, &page->flags.f) && !page_is_fake_head(page);
 }
 
 __SETPAGEFLAG(Head, head, PF_ANY)
···
 	 */
 	if (PageHuge(page))
 		page = compound_head(page);
-	return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+	return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);
 }
 
 static __always_inline void SetPageAnonExclusive(struct page *page)
 {
 	VM_BUG_ON_PGFLAGS(!PageAnonNotKsm(page), page);
 	VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
-	set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+	set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);
 }
 
 static __always_inline void ClearPageAnonExclusive(struct page *page)
 {
 	VM_BUG_ON_PGFLAGS(!PageAnonNotKsm(page), page);
 	VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
-	clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+	clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);
 }
 
 static __always_inline void __ClearPageAnonExclusive(struct page *page)
 {
 	VM_BUG_ON_PGFLAGS(!PageAnon(page), page);
 	VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
-	__clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+	__clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);
 }
 
 #ifdef CONFIG_MMU
···
  */
 static inline int folio_has_private(const struct folio *folio)
 {
-	return !!(folio->flags & PAGE_FLAGS_PRIVATE);
+	return !!(folio->flags.f & PAGE_FLAGS_PRIVATE);
 }
 
 #undef PF_ANY

include/linux/pgalloc_tag.h

···
 	if (static_key_enabled(&mem_profiling_compressed)) {
 		pgalloc_tag_idx idx;
 
-		idx = (page->flags >> alloc_tag_ref_offs) & alloc_tag_ref_mask;
+		idx = (page->flags.f >> alloc_tag_ref_offs) &
+			alloc_tag_ref_mask;
 		idx_to_ref(idx, ref);
 		handle->page = page;
 	} else {
···
 		idx = (unsigned long)ref_to_idx(ref);
 		idx = (idx & alloc_tag_ref_mask) << alloc_tag_ref_offs;
 		do {
-			old_flags = READ_ONCE(page->flags);
+			old_flags = READ_ONCE(page->flags.f);
 			flags = old_flags;
 			flags &= ~(alloc_tag_ref_mask << alloc_tag_ref_offs);
 			flags |= idx;
-		} while (unlikely(!try_cmpxchg(&page->flags, &old_flags, flags)));
+		} while (unlikely(!try_cmpxchg(&page->flags.f, &old_flags, flags)));
 	} else {
 		if (WARN_ON(!handle.ref || !ref))
 			return;

include/trace/events/page_ref.h

···
 
 	TP_fast_assign(
 		__entry->pfn = page_to_pfn(page);
-		__entry->flags = page->flags;
+		__entry->flags = page->flags.f;
 		__entry->count = page_ref_count(page);
 		__entry->mapcount = atomic_read(&page->_mapcount);
 		__entry->mapping = page->mapping;
···
 
 	TP_fast_assign(
 		__entry->pfn = page_to_pfn(page);
-		__entry->flags = page->flags;
+		__entry->flags = page->flags.f;
 		__entry->count = page_ref_count(page);
 		__entry->mapcount = atomic_read(&page->_mapcount);
 		__entry->mapping = page->mapping;

mm/filemap.c

···
 	 */
 	flags = wait->flags;
 	if (flags & WQ_FLAG_EXCLUSIVE) {
-		if (test_bit(key->bit_nr, &key->folio->flags))
+		if (test_bit(key->bit_nr, &key->folio->flags.f))
 			return -1;
 		if (flags & WQ_FLAG_CUSTOM) {
-			if (test_and_set_bit(key->bit_nr, &key->folio->flags))
+			if (test_and_set_bit(key->bit_nr, &key->folio->flags.f))
 				return -1;
 			flags |= WQ_FLAG_DONE;
 		}
···
 					struct wait_queue_entry *wait)
 {
 	if (wait->flags & WQ_FLAG_EXCLUSIVE) {
-		if (test_and_set_bit(bit_nr, &folio->flags))
+		if (test_and_set_bit(bit_nr, &folio->flags.f))
 			return false;
-	} else if (test_bit(bit_nr, &folio->flags))
+	} else if (test_bit(bit_nr, &folio->flags.f))
 		return false;
 
 	wait->flags |= WQ_FLAG_WOKEN | WQ_FLAG_DONE;

mm/huge_memory.c

···
 		 * unreferenced sub-pages of an anonymous THP: we can simply drop
 		 * PG_anon_exclusive (-> PG_mappedtodisk) for these here.
 		 */
-		new_folio->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
-		new_folio->flags |= (folio->flags &
+		new_folio->flags.f &= ~PAGE_FLAGS_CHECK_AT_PREP;
+		new_folio->flags.f |= (folio->flags.f &
 				((1L << PG_referenced) |
 				 (1L << PG_swapbacked) |
 				 (1L << PG_swapcache) |

mm/memory-failure.c

···
 	 * carried out only if the first check can't determine the page status.
 	 */
 	for (ps = error_states;; ps++)
-		if ((p->flags & ps->mask) == ps->res)
+		if ((p->flags.f & ps->mask) == ps->res)
 			break;
 
-	page_flags |= (p->flags & (1UL << PG_dirty));
+	page_flags |= (p->flags.f & (1UL << PG_dirty));
 
 	if (!ps->mask)
 		for (ps = error_states;; ps++)
···
 		return action_result(pfn, MF_MSG_FREE_HUGE, res);
 	}
 
-	page_flags = folio->flags;
+	page_flags = folio->flags.f;
 
 	if (!hwpoison_user_mappings(folio, p, pfn, flags)) {
 		folio_unlock(folio);
···
 	 * folio_remove_rmap_*() in try_to_unmap_one(). So to determine page
 	 * status correctly, we save a copy of the page flags at this time.
 	 */
-	page_flags = folio->flags;
+	page_flags = folio->flags.f;
 
 	/*
 	 * __munlock_folio() may clear a writeback folio's LRU flag without
···
 				putback_movable_pages(&pagelist);
 
 			pr_info("%#lx: %s migration failed %ld, type %pGp\n",
-				pfn, msg_page[huge], ret, &page->flags);
+				pfn, msg_page[huge], ret, &page->flags.f);
 			if (ret > 0)
 				ret = -EBUSY;
 		}
 	} else {
 		pr_info("%#lx: %s isolation failed, page count %d, type %pGp\n",
-			pfn, msg_page[huge], page_count(page), &page->flags);
+			pfn, msg_page[huge], page_count(page), &page->flags.f);
 		ret = -EBUSY;
 	}
 	return ret;

mm/mmzone.c

···
 	unsigned long old_flags, flags;
 	int last_cpupid;
 
-	old_flags = READ_ONCE(folio->flags);
+	old_flags = READ_ONCE(folio->flags.f);
 	do {
 		flags = old_flags;
 		last_cpupid = (flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
 
 		flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
 		flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
-	} while (unlikely(!try_cmpxchg(&folio->flags, &old_flags, flags)));
+	} while (unlikely(!try_cmpxchg(&folio->flags.f, &old_flags, flags)));
 
 	return last_cpupid;
 }

mm/page_alloc.c

···
 	bool to_tail;
 
 	VM_BUG_ON(!zone_is_initialized(zone));
-	VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
+	VM_BUG_ON_PAGE(page->flags.f & PAGE_FLAGS_CHECK_AT_PREP, page);
 
 	VM_BUG_ON(migratetype == -1);
 	VM_BUG_ON_PAGE(pfn & ((1 << order) - 1), page);
···
 			page->memcg_data |
 #endif
 			page_pool_page_is_pp(page) |
-			(page->flags & check_flags)))
+			(page->flags.f & check_flags)))
 		return false;
 
 	return true;
···
 		bad_reason = "non-NULL mapping";
 	if (unlikely(page_ref_count(page) != 0))
 		bad_reason = "nonzero _refcount";
-	if (unlikely(page->flags & flags)) {
+	if (unlikely(page->flags.f & flags)) {
 		if (flags == PAGE_FLAGS_CHECK_AT_PREP)
 			bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag(s) set";
 		else
···
 		int i;
 
 		if (compound) {
-			page[1].flags &= ~PAGE_FLAGS_SECOND;
+			page[1].flags.f &= ~PAGE_FLAGS_SECOND;
 #ifdef NR_PAGES_IN_LARGE_FOLIO
 			folio->_nr_pages = 0;
 #endif
···
 					continue;
 				}
 			}
-			(page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
+			(page + i)->flags.f &= ~PAGE_FLAGS_CHECK_AT_PREP;
 		}
 	}
 	if (folio_test_anon(folio)) {
···
 	}
 
 	page_cpupid_reset_last(page);
-	page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
+	page->flags.f &= ~PAGE_FLAGS_CHECK_AT_PREP;
 	reset_page_owner(page, order);
 	page_table_check_free(page, order);
 	pgalloc_tag_sub(page, 1 << order);

mm/swap.c

···
 
 static void lru_gen_inc_refs(struct folio *folio)
 {
-	unsigned long new_flags, old_flags = READ_ONCE(folio->flags);
+	unsigned long new_flags, old_flags = READ_ONCE(folio->flags.f);
 
 	if (folio_test_unevictable(folio))
 		return;
 
 	/* see the comment on LRU_REFS_FLAGS */
 	if (!folio_test_referenced(folio)) {
-		set_mask_bits(&folio->flags, LRU_REFS_MASK, BIT(PG_referenced));
+		set_mask_bits(&folio->flags.f, LRU_REFS_MASK, BIT(PG_referenced));
 		return;
 	}
 
···
 		}
 
 		new_flags = old_flags + BIT(LRU_REFS_PGOFF);
-	} while (!try_cmpxchg(&folio->flags, &old_flags, new_flags));
+	} while (!try_cmpxchg(&folio->flags.f, &old_flags, new_flags));
 }
 
 static bool lru_gen_clear_refs(struct folio *folio)
···
 	if (gen < 0)
 		return true;
 
-	set_mask_bits(&folio->flags, LRU_REFS_FLAGS | BIT(PG_workingset), 0);
+	set_mask_bits(&folio->flags.f, LRU_REFS_FLAGS | BIT(PG_workingset), 0);
 
 	lrugen = &folio_lruvec(folio)->lrugen;
 	/* whether can do without shuffling under the LRU lock */

mm/vmscan.c

···
 {
 	/* see the comment on LRU_REFS_FLAGS */
 	if (!folio_test_referenced(folio) && !folio_test_workingset(folio)) {
-		set_mask_bits(&folio->flags, LRU_REFS_MASK, BIT(PG_referenced));
+		set_mask_bits(&folio->flags.f, LRU_REFS_MASK, BIT(PG_referenced));
 		return false;
 	}
 
-	set_mask_bits(&folio->flags, LRU_REFS_FLAGS, BIT(PG_workingset));
+	set_mask_bits(&folio->flags.f, LRU_REFS_FLAGS, BIT(PG_workingset));
 	return true;
 }
 #else
···
 /* promote pages accessed through page tables */
 static int folio_update_gen(struct folio *folio, int gen)
 {
-	unsigned long new_flags, old_flags = READ_ONCE(folio->flags);
+	unsigned long new_flags, old_flags = READ_ONCE(folio->flags.f);
 
 	VM_WARN_ON_ONCE(gen >= MAX_NR_GENS);
 
 	/* see the comment on LRU_REFS_FLAGS */
 	if (!folio_test_referenced(folio) && !folio_test_workingset(folio)) {
-		set_mask_bits(&folio->flags, LRU_REFS_MASK, BIT(PG_referenced));
+		set_mask_bits(&folio->flags.f, LRU_REFS_MASK, BIT(PG_referenced));
 		return -1;
 	}
 
···
 
 		new_flags = old_flags & ~(LRU_GEN_MASK | LRU_REFS_FLAGS);
 		new_flags |= ((gen + 1UL) << LRU_GEN_PGOFF) | BIT(PG_workingset);
-	} while (!try_cmpxchg(&folio->flags, &old_flags, new_flags));
+	} while (!try_cmpxchg(&folio->flags.f, &old_flags, new_flags));
 
 	return ((old_flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
 }
···
 	int type = folio_is_file_lru(folio);
 	struct lru_gen_folio *lrugen = &lruvec->lrugen;
 	int new_gen, old_gen = lru_gen_from_seq(lrugen->min_seq[type]);
-	unsigned long new_flags, old_flags = READ_ONCE(folio->flags);
+	unsigned long new_flags, old_flags = READ_ONCE(folio->flags.f);
 
 	VM_WARN_ON_ONCE_FOLIO(!(old_flags & LRU_GEN_MASK), folio);
 
···
 		/* for folio_end_writeback() */
 		if (reclaiming)
 			new_flags |= BIT(PG_reclaim);
-	} while (!try_cmpxchg(&folio->flags, &old_flags, new_flags));
+	} while (!try_cmpxchg(&folio->flags.f, &old_flags, new_flags));
 
 	lru_gen_update_size(lruvec, folio, old_gen, new_gen);
 
···
 
 	/* see the comment on LRU_REFS_FLAGS */
 	if (!folio_test_referenced(folio))
-		set_mask_bits(&folio->flags, LRU_REFS_MASK, 0);
+		set_mask_bits(&folio->flags.f, LRU_REFS_MASK, 0);
 
 	/* for shrink_folio_list() */
 	folio_clear_reclaim(folio);
···
 
 		/* don't add rejected folios to the oldest generation */
 		if (lru_gen_folio_seq(lruvec, folio, false) == min_seq[type])
-			set_mask_bits(&folio->flags, LRU_REFS_FLAGS, BIT(PG_active));
+			set_mask_bits(&folio->flags.f, LRU_REFS_FLAGS, BIT(PG_active));
 	}
 
 	spin_lock_irq(&lruvec->lru_lock);

mm/workingset.c

···
 		folio_set_workingset(folio);
 		mod_lruvec_state(lruvec, WORKINGSET_RESTORE_BASE + type, delta);
 	} else
-		set_mask_bits(&folio->flags, LRU_REFS_MASK, (refs - 1UL) << LRU_REFS_PGOFF);
+		set_mask_bits(&folio->flags.f, LRU_REFS_MASK, (refs - 1UL) << LRU_REFS_PGOFF);
 unlock:
 	rcu_read_unlock();
 }