[PATCH] powerpc: Remove find_current_mm_pte()

From: Christophe Leroy
Date: Wed Mar 09 2022 - 04:30:11 EST


Last usage of find_current_mm_pte() was removed by
commit 15759cb054ef ("powerpc/perf/callchain: Use
__get_user_pages_fast in read_user_stack_slow")

Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/pte-walk.h | 25 -------------------------
arch/powerpc/mm/book3s64/pgtable.c | 4 ++--
2 files changed, 2 insertions(+), 27 deletions(-)

diff --git a/arch/powerpc/include/asm/pte-walk.h b/arch/powerpc/include/asm/pte-walk.h
index 714a35f0d425..73c22c579a79 100644
--- a/arch/powerpc/include/asm/pte-walk.h
+++ b/arch/powerpc/include/asm/pte-walk.h
@@ -60,29 +60,4 @@ static inline phys_addr_t ppc_find_vmap_phys(unsigned long addr)
return pa;
}

-/*
- * This is what we should always use. Any other lockless page table lookup needs
- * careful audit against THP split.
- */
-static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
- bool *is_thp, unsigned *hshift)
-{
- pte_t *pte;
-
- VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
- VM_WARN(pgdir != current->mm->pgd,
- "%s lock less page table lookup called on wrong mm\n", __func__);
- pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
-
-#if defined(CONFIG_DEBUG_VM) && \
- !(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
- /*
- * We should not find huge page if these configs are not enabled.
- */
- if (hshift)
- WARN_ON(*hshift);
-#endif
- return pte;
-}
-
#endif /* _ASM_POWERPC_PTE_WALK_H */
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 79ce3c22a29d..41a41357799d 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -98,14 +98,14 @@ static void do_serialize(void *arg)
}

/*
- * Serialize against find_current_mm_pte which does lock-less
+ * Serialize against __find_linux_pte() which does lock-less
* lookup in page tables with local interrupts disabled. For huge pages
* it casts pmd_t to pte_t. Since format of pte_t is different from
* pmd_t we want to prevent transit from pmd pointing to page table
* to pmd pointing to huge page (and back) while interrupts are disabled.
* We clear pmd to possibly replace it with page table pointer in
* different code paths. So make sure we wait for the parallel
- * find_current_mm_pte to finish.
+ * __find_linux_pte() to finish.
*/
void serialize_against_pte_lookup(struct mm_struct *mm)
{
--
2.34.1