mm/THP: add pmd args to pgtable deposit and withdraw APIs

This will be later used by powerpc THP support.  In powerpc we want to use
pgtable for storing the hash index values.  So instead of adding them to
mm_context list, we would like to store them in the second half of pmd

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index dab90fd..6b785e1 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -730,7 +730,7 @@
 		entry = mk_huge_pmd(page, vma);
 		page_add_new_anon_rmap(page, vma, haddr);
 		set_pmd_at(mm, haddr, pmd, entry);
-		pgtable_trans_huge_deposit(mm, pgtable);
+		pgtable_trans_huge_deposit(mm, pmd, pgtable);
 		add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
 		mm->nr_ptes++;
 		spin_unlock(&mm->page_table_lock);
@@ -772,7 +772,7 @@
 	entry = pmd_wrprotect(entry);
 	entry = pmd_mkhuge(entry);
 	set_pmd_at(mm, haddr, pmd, entry);
-	pgtable_trans_huge_deposit(mm, pgtable);
+	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	mm->nr_ptes++;
 	return true;
 }
@@ -917,7 +917,7 @@
 	pmdp_set_wrprotect(src_mm, addr, src_pmd);
 	pmd = pmd_mkold(pmd_wrprotect(pmd));
 	set_pmd_at(dst_mm, addr, dst_pmd, pmd);
-	pgtable_trans_huge_deposit(dst_mm, pgtable);
+	pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
 	dst_mm->nr_ptes++;
 
 	ret = 0;
@@ -987,7 +987,7 @@
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1085,7 +1085,7 @@
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
@@ -1360,7 +1360,7 @@
 		struct page *page;
 		pgtable_t pgtable;
 		pmd_t orig_pmd;
-		pgtable = pgtable_trans_huge_withdraw(tlb->mm);
+		pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
 		orig_pmd = pmdp_get_and_clear(tlb->mm, addr, pmd);
 		tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
 		if (is_huge_zero_pmd(orig_pmd)) {
@@ -1693,7 +1693,7 @@
 	pmd = page_check_address_pmd(page, mm, address,
 				     PAGE_CHECK_ADDRESS_PMD_SPLITTING_FLAG);
 	if (pmd) {
-		pgtable = pgtable_trans_huge_withdraw(mm);
+		pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 		pmd_populate(mm, &_pmd, pgtable);
 
 		haddr = address;
@@ -2363,7 +2363,7 @@
 	page_add_new_anon_rmap(new_page, vma, address);
 	set_pmd_at(mm, address, pmd, _pmd);
 	update_mmu_cache_pmd(vma, address, pmd);
-	pgtable_trans_huge_deposit(mm, pgtable);
+	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	spin_unlock(&mm->page_table_lock);
 
 	*hpage = NULL;
@@ -2669,7 +2669,7 @@
 	pmdp_clear_flush(vma, haddr, pmd);
 	/* leave pmd empty until pte is filled */
 
-	pgtable = pgtable_trans_huge_withdraw(mm);
+	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 	pmd_populate(mm, &_pmd, pgtable);
 
 	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 0c8323f..e1a6e4f 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -124,7 +124,8 @@
 
 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
+void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				pgtable_t pgtable)
 {
 	assert_spin_locked(&mm->page_table_lock);
 
@@ -141,7 +142,7 @@
 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /* no "address" argument so destroys page coloring of some arch */
-pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
+pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 {
 	pgtable_t pgtable;