[PATCH v3 16/16] mm: replace remaining pte_to_swp_entry() with softleaf_from_pte()

Lorenzo Stoakes
2025-11-10T22:23:31Z

There are straggler invocations of pte_to_swp_entry() lying around, replace
all of these with the software leaf entry equivalent - softleaf_from_pte().

With those removed, eliminate pte_to_swp_entry() altogether.

No functional change intended.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
include/linux/leafops.h | 7 ++++++-
include/linux/swapops.h | 13 -------------
mm/debug_vm_pgtable.c | 2 +-
mm/internal.h | 7 +++++--
mm/memory-failure.c | 2 +-
mm/memory.c | 16 ++++++++--------
mm/migrate.c | 2 +-
mm/mincore.c | 4 +++-
mm/rmap.c | 8 ++++++--
mm/swapfile.c | 13 +++++++++++--
10 files changed, 42 insertions(+), 32 deletions(-)

diff --git a/include/linux/leafops.h b/include/linux/leafops.h
index d282fab866a1..cfafe7a5e7b1 100644
--- a/include/linux/leafops.h
+++ b/include/linux/leafops.h
@@ -54,11 +54,16 @@ static inline softleaf_t softleaf_mk_none(void)
*/
static inline softleaf_t softleaf_from_pte(pte_t pte)
{
+ softleaf_t arch_entry;
+
if (pte_present(pte) || pte_none(pte))
return softleaf_mk_none();

+ pte = pte_swp_clear_flags(pte);
+ arch_entry = __pte_to_swp_entry(pte);
+
/* Temporary until swp_entry_t eliminated. */
- return pte_to_swp_entry(pte);
+ return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
}

/**
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 3d02b288c15e..8cfc966eae48 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -107,19 +107,6 @@ static inline pgoff_t swp_offset(swp_entry_t entry)
return entry.val & SWP_OFFSET_MASK;
}

-/*
- * Convert the arch-dependent pte representation of a swp_entry_t into an
- * arch-independent swp_entry_t.
- */
-static inline swp_entry_t pte_to_swp_entry(pte_t pte)
-{
- swp_entry_t arch_entry;
-
- pte = pte_swp_clear_flags(pte);
- arch_entry = __pte_to_swp_entry(pte);
- return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
-}
-
/*
* Convert the arch-independent representation of a swp_entry_t into the
* arch-dependent pte representation.
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 64db85a80558..1eae87dbef73 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -1229,7 +1229,7 @@ static int __init init_args(struct pgtable_debug_args *args)
init_fixed_pfns(args);

/* See generic_max_swapfile_size(): probe the maximum offset */
- max_swap_offset = swp_offset(pte_to_swp_entry(swp_entry_to_pte(swp_entry(0, ~0UL))));
+ max_swap_offset = swp_offset(softleaf_from_pte(softleaf_to_pte(swp_entry(0, ~0UL))));
/* Create a swp entry with all possible bits set while still being swap. */
args->swp_entry = swp_entry(MAX_SWAPFILES - 1, max_swap_offset);
/* Create a non-present migration entry. */
diff --git a/mm/internal.h b/mm/internal.h
index f0c7461bb02c..985605ba3364 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -334,7 +334,7 @@ unsigned int folio_pte_batch(struct folio *folio, pte_t *ptep, pte_t pte,
*/
static inline pte_t pte_move_swp_offset(pte_t pte, long delta)
{
- swp_entry_t entry = pte_to_swp_entry(pte);
+ const softleaf_t entry = softleaf_from_pte(pte);
pte_t new = __swp_entry_to_pte(__swp_entry(swp_type(entry),
(swp_offset(entry) + delta)));

@@ -389,11 +389,14 @@ static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte)

cgroup_id = lookup_swap_cgroup_id(entry);
while (ptep < end_ptep) {
+ softleaf_t entry;
+
pte = ptep_get(ptep);

if (!pte_same(pte, expected_pte))
break;
- if (lookup_swap_cgroup_id(pte_to_swp_entry(pte)) != cgroup_id)
+ entry = softleaf_from_pte(pte);
+ if (lookup_swap_cgroup_id(entry) != cgroup_id)
break;
expected_pte = pte_next_swp_offset(expected_pte);
ptep++;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 6e79da3de221..ca2204c4647e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -50,7 +50,7 @@
#include <linux/backing-dev.h>
#include <linux/migrate.h>
#include <linux/slab.h>
-#include <linux/swapops.h>
+#include <linux/leafops.h>
#include <linux/hugetlb.h>
#include <linux/memory_hotplug.h>
#include <linux/mm_inline.h>
diff --git a/mm/memory.c b/mm/memory.c
index accd275cd651..f9a2c608aff9 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1218,7 +1218,7 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
spinlock_t *src_ptl, *dst_ptl;
int progress, max_nr, ret = 0;
int rss[NR_MM_COUNTERS];
- swp_entry_t entry = (swp_entry_t){0};
+ softleaf_t entry = softleaf_mk_none();
struct folio *prealloc = NULL;
int nr;

@@ -1282,7 +1282,7 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
dst_vma, src_vma,
addr, rss);
if (ret == -EIO) {
- entry = pte_to_swp_entry(ptep_get(src_pte));
+ entry = softleaf_from_pte(ptep_get(src_pte));
break;
} else if (ret == -EBUSY) {
break;
@@ -4456,13 +4456,13 @@ static struct folio *__alloc_swap_folio(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct folio *folio;
- swp_entry_t entry;
+ softleaf_t entry;

folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma, vmf->address);
if (!folio)
return NULL;

- entry = pte_to_swp_entry(vmf->orig_pte);
+ entry = softleaf_from_pte(vmf->orig_pte);
if (mem_cgroup_swapin_charge_folio(folio, vma->vm_mm,
GFP_KERNEL, entry)) {
folio_put(folio);
@@ -4480,7 +4480,7 @@ static struct folio *__alloc_swap_folio(struct vm_fault *vmf)
static bool can_swapin_thp(struct vm_fault *vmf, pte_t *ptep, int nr_pages)
{
unsigned long addr;
- swp_entry_t entry;
+ softleaf_t entry;
int idx;
pte_t pte;

@@ -4490,7 +4490,7 @@ static bool can_swapin_thp(struct vm_fault *vmf, pte_t *ptep, int nr_pages)

if (!pte_same(pte, pte_move_swp_offset(vmf->orig_pte, -idx)))
return false;
- entry = pte_to_swp_entry(pte);
+ entry = softleaf_from_pte(pte);
if (swap_pte_batch(ptep, nr_pages, pte) != nr_pages)
return false;

@@ -4536,7 +4536,7 @@ static struct folio *alloc_swap_folio(struct vm_fault *vmf)
unsigned long orders;
struct folio *folio;
unsigned long addr;
- swp_entry_t entry;
+ softleaf_t entry;
spinlock_t *ptl;
pte_t *pte;
gfp_t gfp;
@@ -4557,7 +4557,7 @@ static struct folio *alloc_swap_folio(struct vm_fault *vmf)
if (!zswap_never_enabled())
goto fallback;

- entry = pte_to_swp_entry(vmf->orig_pte);
+ entry = softleaf_from_pte(vmf->orig_pte);
/*
* Get a list of all the (large) orders below PMD_ORDER that are enabled
* and suitable for swapping THP.
diff --git a/mm/migrate.c b/mm/migrate.c
index 182a5b7b2ead..c01bc0ddf819 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -534,7 +534,7 @@ void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, p
* lock release in migration_entry_wait_on_locked().
*/
hugetlb_vma_unlock_read(vma);
- migration_entry_wait_on_locked(pte_to_swp_entry(pte), ptl);
+ migration_entry_wait_on_locked(entry, ptl);
return;
}

diff --git a/mm/mincore.c b/mm/mincore.c
index 9a908d8bb706..e5d13eea9234 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -202,7 +202,9 @@ static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
for (i = 0; i < step; i++)
vec[i] = 1;
} else { /* pte is a swap entry */
- *vec = mincore_swap(pte_to_swp_entry(pte), false);
+ const softleaf_t entry = softleaf_from_pte(pte);
+
+ *vec = mincore_swap(entry, false);
}
vec += step;
}
diff --git a/mm/rmap.c b/mm/rmap.c
index 345466ad396b..d871f2eb821c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1969,7 +1969,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
if (likely(pte_present(pteval))) {
pfn = pte_pfn(pteval);
} else {
- pfn = softleaf_to_pfn(pte_to_swp_entry(pteval));
+ const softleaf_t entry = softleaf_from_pte(pteval);
+
+ pfn = softleaf_to_pfn(entry);
VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio);
}

@@ -2368,7 +2370,9 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
if (likely(pte_present(pteval))) {
pfn = pte_pfn(pteval);
} else {
- pfn = softleaf_to_pfn(pte_to_swp_entry(pteval));
+ const softleaf_t entry = softleaf_from_pte(pteval);
+
+ pfn = softleaf_to_pfn(entry);
VM_WARN_ON_FOLIO(folio_test_hugetlb(folio), folio);
}

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 684f78cd7dd1..e5667a31be9f 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3201,8 +3201,17 @@ static int claim_swapfile(struct swap_info_struct *si, struct inode *inode)
*/
unsigned long generic_max_swapfile_size(void)
{
- return swp_offset(pte_to_swp_entry(
- swp_entry_to_pte(swp_entry(0, ~0UL)))) + 1;
+ swp_entry_t entry = swp_entry(0, ~0UL);
+ const pte_t pte = softleaf_to_pte(entry);
+
+ /*
+ * Since the PTE can be an invalid softleaf entry (e.g. the none PTE),
+ * we need to do this manually.
+ */
+ entry = __pte_to_swp_entry(pte);
+ entry = swp_entry(__swp_type(entry), __swp_offset(entry));
+
+ return swp_offset(entry) + 1;
}

/* Can be overridden by an architecture for additional checks. */
--
2.51.0