[PATCH 13/14] mm: pgtable: remove pte_offset_map_nolock()

From: Qi Zheng
Date: Wed Aug 21 2024 - 05:05:03 EST


Now no users are using the pte_offset_map_nolock(), remove it.

Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
Documentation/mm/split_page_table_lock.rst | 3 ---
include/linux/mm.h | 2 --
mm/pgtable-generic.c | 21 ---------------------
3 files changed, 26 deletions(-)

diff --git a/Documentation/mm/split_page_table_lock.rst b/Documentation/mm/split_page_table_lock.rst
index f54f717ae8bdf..596b425fb28e6 100644
--- a/Documentation/mm/split_page_table_lock.rst
+++ b/Documentation/mm/split_page_table_lock.rst
@@ -16,9 +16,6 @@ There are helpers to lock/unlock a table and other accessor functions:
- pte_offset_map_lock()
maps PTE and takes PTE table lock, returns pointer to PTE with
pointer to its PTE table lock, or returns NULL if no PTE table;
- - pte_offset_map_nolock()
- maps PTE, returns pointer to PTE with pointer to its PTE table
- lock (not taken), or returns NULL if no PTE table;
- pte_offset_map_readonly_nolock()
maps PTE, returns pointer to PTE with pointer to its PTE table
lock (not taken), or returns NULL if no PTE table;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1fe0ceabcaf39..f7c207c3ab701 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2952,8 +2952,6 @@ static inline pte_t *pte_offset_map_lock(struct mm_struct *mm, pmd_t *pmd,
return pte;
}

-pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd,
- unsigned long addr, spinlock_t **ptlp);
pte_t *pte_offset_map_readonly_nolock(struct mm_struct *mm, pmd_t *pmd,
unsigned long addr, spinlock_t **ptlp);
pte_t *pte_offset_map_maywrite_nolock(struct mm_struct *mm, pmd_t *pmd,
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 29d1fd6fd2963..9ba2e423bdb41 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -305,18 +305,6 @@ pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp)
return NULL;
}

-pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd,
- unsigned long addr, spinlock_t **ptlp)
-{
- pmd_t pmdval;
- pte_t *pte;
-
- pte = __pte_offset_map(pmd, addr, &pmdval);
- if (likely(pte))
- *ptlp = pte_lockptr(mm, &pmdval);
- return pte;
-}
-
pte_t *pte_offset_map_readonly_nolock(struct mm_struct *mm, pmd_t *pmd,
unsigned long addr, spinlock_t **ptlp)
{
@@ -374,15 +362,6 @@ pte_t *pte_offset_map_maywrite_nolock(struct mm_struct *mm, pmd_t *pmd,
* and disconnected table. Until pte_unmap(pte) unmaps and rcu_read_unlock()s
* afterwards.
*
- * pte_offset_map_nolock(mm, pmd, addr, ptlp), above, is like pte_offset_map();
- * but when successful, it also outputs a pointer to the spinlock in ptlp - as
- * pte_offset_map_lock() does, but in this case without locking it. This helps
- * the caller to avoid a later pte_lockptr(mm, *pmd), which might by that time
- * act on a changed *pmd: pte_offset_map_nolock() provides the correct spinlock
- * pointer for the page table that it returns. In principle, the caller should
- * recheck *pmd once the lock is taken; in practice, no callsite needs that -
- * either the mmap_lock for write, or pte_same() check on contents, is enough.
- *
* pte_offset_map_readonly_nolock(mm, pmd, addr, ptlp), above, is like
* pte_offset_map(); but when successful, it also outputs a pointer to the
* spinlock in ptlp - as pte_offset_map_lock() does, but in this case without
--
2.20.1