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>

2 files changed, 12 insertions, 11 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index dab90fd67298..6b785e17b679 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -730,7 +730,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 		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 @@ static bool set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm,
 	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 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	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 @@ static int do_huge_pmd_wp_zero_page_fallback(struct mm_struct *mm,
 	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 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 	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 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		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 @@ static int __split_huge_page_map(struct page *page,
 	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 @@ static void collapse_huge_page(struct mm_struct *mm,
 	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 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
 	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 0c8323fe6c8f..e1a6e4fab016 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -124,7 +124,8 @@ void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 
 #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 @@ void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
 #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;