[PATCH v4 17/34] s390: Convert various pgalloc functions to use ptdescs

["Vishal Moola (Oracle)" <vishal.moola@gmail.com>]

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 arch/s390/include/asm/pgalloc.h |   4 +-
 arch/s390/include/asm/tlb.h     |   4 +-
 arch/s390/mm/pgalloc.c          | 108 ++++++++++++++++----------------
 3 files changed, 59 insertions(+), 57 deletions(-)

diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index 17eb618f1348..00ad9b88fda9 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -86,7 +86,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
 	if (!table)
 		return NULL;
 	crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
-	if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
+	if (!pagetable_pmd_ctor(virt_to_ptdesc(table))) {
 		crst_table_free(mm, table);
 		return NULL;
 	}
@@ -97,7 +97,7 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
 	if (mm_pmd_folded(mm))
 		return;
-	pgtable_pmd_page_dtor(virt_to_page(pmd));
+	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
 	crst_table_free(mm, (unsigned long *) pmd);
 }
 
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
index b91f4a9b044c..383b1f91442c 100644
--- a/arch/s390/include/asm/tlb.h
+++ b/arch/s390/include/asm/tlb.h
@@ -89,12 +89,12 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
 {
 	if (mm_pmd_folded(tlb->mm))
 		return;
-	pgtable_pmd_page_dtor(virt_to_page(pmd));
+	pagetable_pmd_dtor(virt_to_ptdesc(pmd));
 	__tlb_adjust_range(tlb, address, PAGE_SIZE);
 	tlb->mm->context.flush_mm = 1;
 	tlb->freed_tables = 1;
 	tlb->cleared_puds = 1;
-	tlb_remove_table(tlb, pmd);
+	tlb_remove_ptdesc(tlb, pmd);
 }
 
 /*
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 6b99932abc66..eeb7c95b98cf 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -43,17 +43,17 @@ __initcall(page_table_register_sysctl);
 
 unsigned long *crst_table_alloc(struct mm_struct *mm)
 {
-	struct page *page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+	struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
 
-	if (!page)
+	if (!ptdesc)
 		return NULL;
-	arch_set_page_dat(page, CRST_ALLOC_ORDER);
-	return (unsigned long *) page_to_virt(page);
+	arch_set_page_dat(ptdesc_page(ptdesc), CRST_ALLOC_ORDER);
+	return (unsigned long *) ptdesc_to_virt(ptdesc);
 }
 
 void crst_table_free(struct mm_struct *mm, unsigned long *table)
 {
-	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
+	pagetable_free(virt_to_ptdesc(table));
 }
 
 static void __crst_table_upgrade(void *arg)
@@ -140,21 +140,21 @@ static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
 
 struct page *page_table_alloc_pgste(struct mm_struct *mm)
 {
-	struct page *page;
+	struct ptdesc *ptdesc;
 	u64 *table;
 
-	page = alloc_page(GFP_KERNEL);
-	if (page) {
-		table = (u64 *)page_to_virt(page);
+	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
+	if (ptdesc) {
+		table = (u64 *)ptdesc_to_virt(ptdesc);
 		memset64(table, _PAGE_INVALID, PTRS_PER_PTE);
 		memset64(table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 	}
-	return page;
+	return ptdesc_page(ptdesc);
 }
 
 void page_table_free_pgste(struct page *page)
 {
-	__free_page(page);
+	pagetable_free(page_ptdesc(page));
 }
 
 #endif /* CONFIG_PGSTE */
@@ -230,7 +230,7 @@ void page_table_free_pgste(struct page *page)
 unsigned long *page_table_alloc(struct mm_struct *mm)
 {
 	unsigned long *table;
-	struct page *page;
+	struct ptdesc *ptdesc;
 	unsigned int mask, bit;
 
 	/* Try to get a fragment of a 4K page as a 2K page table */
@@ -238,9 +238,9 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 		table = NULL;
 		spin_lock_bh(&mm->context.lock);
 		if (!list_empty(&mm->context.pgtable_list)) {
-			page = list_first_entry(&mm->context.pgtable_list,
-						struct page, lru);
-			mask = atomic_read(&page->pt_frag_refcount);
+			ptdesc = list_first_entry(&mm->context.pgtable_list,
+						struct ptdesc, pt_list);
+			mask = atomic_read(&ptdesc->pt_frag_refcount);
 			/*
 			 * The pending removal bits must also be checked.
 			 * Failure to do so might lead to an impossible
@@ -253,13 +253,13 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 			 */
 			mask = (mask | (mask >> 4)) & 0x03U;
 			if (mask != 0x03U) {
-				table = (unsigned long *) page_to_virt(page);
+				table = (unsigned long *) ptdesc_to_virt(ptdesc);
 				bit = mask & 1;		/* =1 -> second 2K */
 				if (bit)
 					table += PTRS_PER_PTE;
-				atomic_xor_bits(&page->pt_frag_refcount,
+				atomic_xor_bits(&ptdesc->pt_frag_refcount,
 							0x01U << bit);
-				list_del(&page->lru);
+				list_del(&ptdesc->pt_list);
 			}
 		}
 		spin_unlock_bh(&mm->context.lock);
@@ -267,27 +267,27 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
 			return table;
 	}
 	/* Allocate a fresh page */
-	page = alloc_page(GFP_KERNEL);
-	if (!page)
+	ptdesc = pagetable_alloc(GFP_KERNEL, 0);
+	if (!ptdesc)
 		return NULL;
-	if (!pgtable_pte_page_ctor(page)) {
-		__free_page(page);
+	if (!pagetable_pte_ctor(ptdesc)) {
+		pagetable_free(ptdesc);
 		return NULL;
 	}
-	arch_set_page_dat(page, 0);
+	arch_set_page_dat(ptdesc_page(ptdesc), 0);
 	/* Initialize page table */
-	table = (unsigned long *) page_to_virt(page);
+	table = (unsigned long *) ptdesc_to_virt(ptdesc);
 	if (mm_alloc_pgste(mm)) {
 		/* Return 4K page table with PGSTEs */
-		atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
+		atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
 		memset64((u64 *)table, _PAGE_INVALID, PTRS_PER_PTE);
 		memset64((u64 *)table + PTRS_PER_PTE, 0, PTRS_PER_PTE);
 	} else {
 		/* Return the first 2K fragment of the page */
-		atomic_xor_bits(&page->pt_frag_refcount, 0x01U);
+		atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x01U);
 		memset64((u64 *)table, _PAGE_INVALID, 2 * PTRS_PER_PTE);
 		spin_lock_bh(&mm->context.lock);
-		list_add(&page->lru, &mm->context.pgtable_list);
+		list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
 		spin_unlock_bh(&mm->context.lock);
 	}
 	return table;
@@ -309,9 +309,8 @@ static void page_table_release_check(struct page *page, void *table,
 void page_table_free(struct mm_struct *mm, unsigned long *table)
 {
 	unsigned int mask, bit, half;
-	struct page *page;
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
-	page = virt_to_page(table);
 	if (!mm_alloc_pgste(mm)) {
 		/* Free 2K page table fragment of a 4K page */
 		bit = ((unsigned long) table & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));
@@ -321,39 +320,38 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
 		 * will happen outside of the critical section from this
 		 * function or from __tlb_remove_table()
 		 */
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x11U << bit);
 		if (mask & 0x03U)
-			list_add(&page->lru, &mm->context.pgtable_list);
+			list_add(&ptdesc->pt_list, &mm->context.pgtable_list);
 		else
-			list_del(&page->lru);
+			list_del(&ptdesc->pt_list);
 		spin_unlock_bh(&mm->context.lock);
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x10U << bit);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x10U << bit);
 		if (mask != 0x00U)
 			return;
 		half = 0x01U << bit;
 	} else {
 		half = 0x03U;
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
 	}
 
-	page_table_release_check(page, table, half, mask);
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 			 unsigned long vmaddr)
 {
 	struct mm_struct *mm;
-	struct page *page;
 	unsigned int bit, mask;
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
 	mm = tlb->mm;
-	page = virt_to_page(table);
 	if (mm_alloc_pgste(mm)) {
 		gmap_unlink(mm, table, vmaddr);
 		table = (unsigned long *) ((unsigned long)table | 0x03U);
-		tlb_remove_table(tlb, table);
+		tlb_remove_ptdesc(tlb, table);
 		return;
 	}
 	bit = ((unsigned long) table & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));
@@ -363,11 +361,11 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table,
 	 * outside of the critical section from __tlb_remove_table() or from
 	 * page_table_free()
 	 */
-	mask = atomic_xor_bits(&page->pt_frag_refcount, 0x11U << bit);
+	mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x11U << bit);
 	if (mask & 0x03U)
-		list_add_tail(&page->lru, &mm->context.pgtable_list);
+		list_add_tail(&ptdesc->pt_list, &mm->context.pgtable_list);
 	else
-		list_del(&page->lru);
+		list_del(&ptdesc->pt_list);
 	spin_unlock_bh(&mm->context.lock);
 	table = (unsigned long *) ((unsigned long) table | (0x01U << bit));
 	tlb_remove_table(tlb, table);
@@ -377,7 +375,7 @@ void __tlb_remove_table(void *_table)
 {
 	unsigned int mask = (unsigned long) _table & 0x03U, half = mask;
 	void *table = (void *)((unsigned long) _table ^ mask);
-	struct page *page = virt_to_page(table);
+	struct ptdesc *ptdesc = virt_to_ptdesc(table);
 
 	switch (half) {
 	case 0x00U:	/* pmd, pud, or p4d */
@@ -385,18 +383,18 @@ void __tlb_remove_table(void *_table)
 		return;
 	case 0x01U:	/* lower 2K of a 4K page table */
 	case 0x02U:	/* higher 2K of a 4K page table */
-		mask = atomic_xor_bits(&page->pt_frag_refcount, mask << 4);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, mask << 4);
 		if (mask != 0x00U)
 			return;
 		break;
 	case 0x03U:	/* 4K page table with pgstes */
-		mask = atomic_xor_bits(&page->pt_frag_refcount, 0x03U);
+		mask = atomic_xor_bits(&ptdesc->pt_frag_refcount, 0x03U);
 		break;
 	}
 
-	page_table_release_check(page, table, half, mask);
-	pgtable_pte_page_dtor(page);
-	__free_page(page);
+	page_table_release_check(ptdesc_page(ptdesc), table, half, mask);
+	pagetable_pte_dtor(ptdesc);
+	pagetable_free(ptdesc);
 }
 
 /*
@@ -424,16 +422,20 @@ static void base_pgt_free(unsigned long *table)
 static unsigned long *base_crst_alloc(unsigned long val)
 {
 	unsigned long *table;
+	struct ptdesc *ptdesc;
 
-	table =	(unsigned long *)__get_free_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
-	if (table)
-		crst_table_init(table, val);
+	ptdesc = pagetable_alloc(GFP_KERNEL, CRST_ALLOC_ORDER);
+	if (!ptdesc)
+		return NULL;
+	table = ptdesc_address(ptdesc);
+
+	crst_table_init(table, val);
 	return table;
 }
 
 static void base_crst_free(unsigned long *table)
 {
-	free_pages((unsigned long)table, CRST_ALLOC_ORDER);
+	pagetable_free(virt_to_ptdesc(table));
 }
 
 #define BASE_ADDR_END_FUNC(NAME, SIZE)					\
-- 
2.40.1