mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVES

CONFIG_ARCH_ENABLE_THP_MIGRATION gates PMD-level migration entries. 
PMD-level device-private entries use the same migration mechanism and
therefore require the same architecture support.

Upcoming PMD-level swap entries can use the same PMD softleaf helpers
without depending on page migration, so rename the architecture gate to
CONFIG_ARCH_HAS_PMD_SOFTLEAVES.  This describes the PMD entry capability
rather than one current user of it.

This is a pure rename: the set of selecting architectures (x86, arm64,
s390, riscv, loongarch, and powerpc on PPC_BOOK3S_64) and the gating
semantics are unchanged.

No functional change intended.

Link: https://lore.kernel.org/20260706114320.1643046-7-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

4 files changed, 9 insertions, 9 deletions

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index ad20f7f8c179..b34e8e5e5f9a 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -567,7 +567,7 @@ static inline struct folio *get_persistent_huge_zero_folio(void)
 
 static inline bool thp_migration_supported(void)
 {
-	return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
+	return IS_ENABLED(CONFIG_ARCH_HAS_PMD_SOFTLEAVES);
 }
 
 void split_huge_pmd_locked(struct vm_area_struct *vma, unsigned long address,
diff --git a/include/linux/leafops.h b/include/linux/leafops.h
index 803d312437df..ef84ac1cce19 100644
--- a/include/linux/leafops.h
+++ b/include/linux/leafops.h
@@ -81,7 +81,7 @@ static inline pte_t softleaf_to_pte(softleaf_t entry)
 	return swp_entry_to_pte(entry);
 }
 
-#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+#ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
 /**
  * softleaf_from_pmd() - Obtain a leaf entry from a PMD entry.
  * @pmd: PMD entry.
@@ -587,7 +587,7 @@ static inline bool pte_is_uffd_marker(pte_t pte)
 	return false;
 }
 
-#if defined(CONFIG_ZONE_DEVICE) && defined(CONFIG_ARCH_ENABLE_THP_MIGRATION)
+#if defined(CONFIG_ZONE_DEVICE) && defined(CONFIG_ARCH_HAS_PMD_SOFTLEAVES)
 
 /**
  * pmd_is_device_private_entry() - Check if PMD contains a device private swap
@@ -606,14 +606,14 @@ static inline bool pmd_is_device_private_entry(pmd_t pmd)
 	return softleaf_is_device_private(softleaf_from_pmd(pmd));
 }
 
-#else  /* CONFIG_ZONE_DEVICE && CONFIG_ARCH_ENABLE_THP_MIGRATION */
+#else  /* CONFIG_ZONE_DEVICE && CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
 
 static inline bool pmd_is_device_private_entry(pmd_t pmd)
 {
 	return false;
 }
 
-#endif /* CONFIG_ZONE_DEVICE && CONFIG_ARCH_ENABLE_THP_MIGRATION */
+#endif /* CONFIG_ZONE_DEVICE && CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
 
 /**
  * pmd_is_migration_entry() - Does this PMD entry encode a migration entry?
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index d52d2a976e5a..3df6db1e9e39 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1839,7 +1839,7 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
 #endif
 
 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
-#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
+#ifndef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
 static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
 {
 	return pmd;
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 8cfc966eae48..1125401b787e 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -321,7 +321,7 @@ static inline swp_entry_t make_guard_swp_entry(void)
 
 struct page_vma_mapped_walk;
 
-#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+#ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
 extern int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
 		struct page *page);
 
@@ -338,7 +338,7 @@ static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
 	return __swp_entry_to_pmd(arch_entry);
 }
 
-#else  /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
+#else  /* CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
 static inline int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
 		struct page *page)
 {
@@ -358,7 +358,7 @@ static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
 	return __pmd(0);
 }
 
-#endif  /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
+#endif  /* CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
 
 #endif /* CONFIG_MMU */
 #endif /* _LINUX_SWAPOPS_H */