s390/mm: cleanup page table definitions

Improve the encoding of the different pte types and the naming of the
page, segment table and region table bits. Due to the different pte
encoding the hugetlbfs primitives need to be adapted as well. To improve
compatability with common code make the huge ptes use the encoding of
normal ptes. The conversion between the pte and pmd encoding for a huge
pte is done with set_huge_pte_at and huge_ptep_get.
Overall the code is now easier to understand.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 30 insertions, 29 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index a8154a1..b9d35d6 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -161,7 +161,7 @@ static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table)
 	struct gmap_rmap *rmap;
 	struct page *page;
 
-	if (*table & _SEGMENT_ENTRY_INV)
+	if (*table & _SEGMENT_ENTRY_INVALID)
 		return 0;
 	page = pfn_to_page(*table >> PAGE_SHIFT);
 	mp = (struct gmap_pgtable *) page->index;
@@ -172,7 +172,7 @@ static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table)
 		kfree(rmap);
 		break;
 	}
-	*table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
+	*table = mp->vmaddr | _SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_PROTECT;
 	return 1;
 }
 
@@ -258,7 +258,7 @@ static int gmap_alloc_table(struct gmap *gmap,
 		return -ENOMEM;
 	new = (unsigned long *) page_to_phys(page);
 	crst_table_init(new, init);
-	if (*table & _REGION_ENTRY_INV) {
+	if (*table & _REGION_ENTRY_INVALID) {
 		list_add(&page->lru, &gmap->crst_list);
 		*table = (unsigned long) new | _REGION_ENTRY_LENGTH |
 			(*table & _REGION_ENTRY_TYPE_MASK);
@@ -292,22 +292,22 @@ int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
 	for (off = 0; off < len; off += PMD_SIZE) {
 		/* Walk the guest addr space page table */
 		table = gmap->table + (((to + off) >> 53) & 0x7ff);
-		if (*table & _REGION_ENTRY_INV)
+		if (*table & _REGION_ENTRY_INVALID)
 			goto out;
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + (((to + off) >> 42) & 0x7ff);
-		if (*table & _REGION_ENTRY_INV)
+		if (*table & _REGION_ENTRY_INVALID)
 			goto out;
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + (((to + off) >> 31) & 0x7ff);
-		if (*table & _REGION_ENTRY_INV)
+		if (*table & _REGION_ENTRY_INVALID)
 			goto out;
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + (((to + off) >> 20) & 0x7ff);
 
 		/* Clear segment table entry in guest address space. */
 		flush |= gmap_unlink_segment(gmap, table);
-		*table = _SEGMENT_ENTRY_INV;
+		*table = _SEGMENT_ENTRY_INVALID;
 	}
 out:
 	spin_unlock(&gmap->mm->page_table_lock);
@@ -345,17 +345,17 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
 	for (off = 0; off < len; off += PMD_SIZE) {
 		/* Walk the gmap address space page table */
 		table = gmap->table + (((to + off) >> 53) & 0x7ff);
-		if ((*table & _REGION_ENTRY_INV) &&
+		if ((*table & _REGION_ENTRY_INVALID) &&
 		    gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY))
 			goto out_unmap;
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + (((to + off) >> 42) & 0x7ff);
-		if ((*table & _REGION_ENTRY_INV) &&
+		if ((*table & _REGION_ENTRY_INVALID) &&
 		    gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY))
 			goto out_unmap;
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + (((to + off) >> 31) & 0x7ff);
-		if ((*table & _REGION_ENTRY_INV) &&
+		if ((*table & _REGION_ENTRY_INVALID) &&
 		    gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY))
 			goto out_unmap;
 		table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN);
@@ -363,7 +363,8 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
 
 		/* Store 'from' address in an invalid segment table entry. */
 		flush |= gmap_unlink_segment(gmap, table);
-		*table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | (from + off);
+		*table =  (from + off) | (_SEGMENT_ENTRY_INVALID |
+					  _SEGMENT_ENTRY_PROTECT);
 	}
 	spin_unlock(&gmap->mm->page_table_lock);
 	up_read(&gmap->mm->mmap_sem);
@@ -384,15 +385,15 @@ static unsigned long *gmap_table_walk(unsigned long address, struct gmap *gmap)
 	unsigned long *table;
 
 	table = gmap->table + ((address >> 53) & 0x7ff);
-	if (unlikely(*table & _REGION_ENTRY_INV))
+	if (unlikely(*table & _REGION_ENTRY_INVALID))
 		return ERR_PTR(-EFAULT);
 	table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 	table = table + ((address >> 42) & 0x7ff);
-	if (unlikely(*table & _REGION_ENTRY_INV))
+	if (unlikely(*table & _REGION_ENTRY_INVALID))
 		return ERR_PTR(-EFAULT);
 	table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 	table = table + ((address >> 31) & 0x7ff);
-	if (unlikely(*table & _REGION_ENTRY_INV))
+	if (unlikely(*table & _REGION_ENTRY_INVALID))
 		return ERR_PTR(-EFAULT);
 	table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 	table = table + ((address >> 20) & 0x7ff);
@@ -422,11 +423,11 @@ unsigned long __gmap_translate(unsigned long address, struct gmap *gmap)
 		return PTR_ERR(segment_ptr);
 	/* Convert the gmap address to an mm address. */
 	segment = *segment_ptr;
-	if (!(segment & _SEGMENT_ENTRY_INV)) {
+	if (!(segment & _SEGMENT_ENTRY_INVALID)) {
 		page = pfn_to_page(segment >> PAGE_SHIFT);
 		mp = (struct gmap_pgtable *) page->index;
 		return mp->vmaddr | (address & ~PMD_MASK);
-	} else if (segment & _SEGMENT_ENTRY_RO) {
+	} else if (segment & _SEGMENT_ENTRY_PROTECT) {
 		vmaddr = segment & _SEGMENT_ENTRY_ORIGIN;
 		return vmaddr | (address & ~PMD_MASK);
 	}
@@ -517,8 +518,8 @@ static void gmap_disconnect_pgtable(struct mm_struct *mm, unsigned long *table)
 	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
 	mp = (struct gmap_pgtable *) page->index;
 	list_for_each_entry_safe(rmap, next, &mp->mapper, list) {
-		*rmap->entry =
-			_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
+		*rmap->entry = mp->vmaddr | (_SEGMENT_ENTRY_INVALID |
+					     _SEGMENT_ENTRY_PROTECT);
 		list_del(&rmap->list);
 		kfree(rmap);
 		flush = 1;
@@ -545,13 +546,13 @@ unsigned long __gmap_fault(unsigned long address, struct gmap *gmap)
 	/* Convert the gmap address to an mm address. */
 	while (1) {
 		segment = *segment_ptr;
-		if (!(segment & _SEGMENT_ENTRY_INV)) {
+		if (!(segment & _SEGMENT_ENTRY_INVALID)) {
 			/* Page table is present */
 			page = pfn_to_page(segment >> PAGE_SHIFT);
 			mp = (struct gmap_pgtable *) page->index;
 			return mp->vmaddr | (address & ~PMD_MASK);
 		}
-		if (!(segment & _SEGMENT_ENTRY_RO))
+		if (!(segment & _SEGMENT_ENTRY_PROTECT))
 			/* Nothing mapped in the gmap address space. */
 			break;
 		rc = gmap_connect_pgtable(address, segment, segment_ptr, gmap);
@@ -586,25 +587,25 @@ void gmap_discard(unsigned long from, unsigned long to, struct gmap *gmap)
 	while (address < to) {
 		/* Walk the gmap address space page table */
 		table = gmap->table + ((address >> 53) & 0x7ff);
-		if (unlikely(*table & _REGION_ENTRY_INV)) {
+		if (unlikely(*table & _REGION_ENTRY_INVALID)) {
 			address = (address + PMD_SIZE) & PMD_MASK;
 			continue;
 		}
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + ((address >> 42) & 0x7ff);
-		if (unlikely(*table & _REGION_ENTRY_INV)) {
+		if (unlikely(*table & _REGION_ENTRY_INVALID)) {
 			address = (address + PMD_SIZE) & PMD_MASK;
 			continue;
 		}
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + ((address >> 31) & 0x7ff);
-		if (unlikely(*table & _REGION_ENTRY_INV)) {
+		if (unlikely(*table & _REGION_ENTRY_INVALID)) {
 			address = (address + PMD_SIZE) & PMD_MASK;
 			continue;
 		}
 		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
 		table = table + ((address >> 20) & 0x7ff);
-		if (unlikely(*table & _SEGMENT_ENTRY_INV)) {
+		if (unlikely(*table & _SEGMENT_ENTRY_INVALID)) {
 			address = (address + PMD_SIZE) & PMD_MASK;
 			continue;
 		}
@@ -687,7 +688,7 @@ int gmap_ipte_notify(struct gmap *gmap, unsigned long start, unsigned long len)
 			continue;
 		/* Set notification bit in the pgste of the pte */
 		entry = *ptep;
-		if ((pte_val(entry) & (_PAGE_INVALID | _PAGE_RO)) == 0) {
+		if ((pte_val(entry) & (_PAGE_INVALID | _PAGE_PROTECT)) == 0) {
 			pgste = pgste_get_lock(ptep);
 			pgste_val(pgste) |= PGSTE_IN_BIT;
 			pgste_set_unlock(ptep, pgste);
@@ -752,7 +753,7 @@ static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
 	page->index = (unsigned long) mp;
 	atomic_set(&page->_mapcount, 3);
 	table = (unsigned long *) page_to_phys(page);
-	clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE/2);
+	clear_table(table, _PAGE_INVALID, PAGE_SIZE/2);
 	clear_table(table + PTRS_PER_PTE, 0, PAGE_SIZE/2);
 	return table;
 }
@@ -878,7 +879,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr)
 		pgtable_page_ctor(page);
 		atomic_set(&page->_mapcount, 1);
 		table = (unsigned long *) page_to_phys(page);
-		clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
+		clear_table(table, _PAGE_INVALID, PAGE_SIZE);
 		spin_lock_bh(&mm->context.list_lock);
 		list_add(&page->lru, &mm->context.pgtable_list);
 	} else {
@@ -1198,9 +1199,9 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 		list_del(lh);
 	}
 	ptep = (pte_t *) pgtable;
-	pte_val(*ptep) = _PAGE_TYPE_EMPTY;
+	pte_val(*ptep) = _PAGE_INVALID;
 	ptep++;
-	pte_val(*ptep) = _PAGE_TYPE_EMPTY;
+	pte_val(*ptep) = _PAGE_INVALID;
 	return pgtable;
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */