powerpc/mm: Use pmd_lockptr instead of opencoding it

In later patch we switch pmd_lock from mm->page_table_lock to split pmd ptlock.
It avoid compilations issues, use pmd_lockptr helper.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/pgtable-book3s64.c

@@ -37,7 +37,7 @@ int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
 	int changed;
 #ifdef CONFIG_DEBUG_VM
 	WARN_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
-	assert_spin_locked(&vma->vm_mm->page_table_lock);
+	assert_spin_locked(pmd_lockptr(vma->vm_mm, pmdp));
 #endif
 	changed = !pmd_same(*(pmdp), entry);
 	if (changed) {
@@ -62,7 +62,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 {
 #ifdef CONFIG_DEBUG_VM
 	WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
-	assert_spin_locked(&mm->page_table_lock);
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
 	WARN_ON(!(pmd_trans_huge(pmd) || pmd_devmap(pmd)));
 #endif
 	trace_hugepage_set_pmd(addr, pmd_val(pmd));

arch/powerpc/mm/pgtable-hash64.c

@@ -193,7 +193,7 @@ unsigned long hash__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr
 
 #ifdef CONFIG_DEBUG_VM
 	WARN_ON(!hash__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
-	assert_spin_locked(&mm->page_table_lock);
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
 #endif
 
 	__asm__ __volatile__(
@@ -265,7 +265,8 @@ void hash__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 				  pgtable_t pgtable)
 {
 	pgtable_t *pgtable_slot;
-	assert_spin_locked(&mm->page_table_lock);
+
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
 	/*
 	 * we store the pgtable in the second half of PMD
 	 */
@@ -285,7 +286,8 @@ pgtable_t hash__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 	pgtable_t pgtable;
 	pgtable_t *pgtable_slot;
 
-	assert_spin_locked(&mm->page_table_lock);
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
+
 	pgtable_slot = (pgtable_t *)pmdp + PTRS_PER_PMD;
 	pgtable = *pgtable_slot;
 	/*

arch/powerpc/mm/pgtable-radix.c

@@ -975,7 +975,7 @@ unsigned long radix__pmd_hugepage_update(struct mm_struct *mm, unsigned long add
 
 #ifdef CONFIG_DEBUG_VM
 	WARN_ON(!radix__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
-	assert_spin_locked(&mm->page_table_lock);
+	assert_spin_locked(pmd_lockptr(mm, pmdp));
 #endif
 
 	old = radix__pte_update(mm, addr, (pte_t *)pmdp, clr, set, 1);