1 files changed, 398 insertions, 23 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 37a23c223705..2adb23938a7f 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -16,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/quicklist.h>
 #include <linux/rcupdate.h>
+#include <linux/slab.h>
 
 #include <asm/system.h>
 #include <asm/pgtable.h>
@@ -133,30 +134,374 @@ void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
 }
 #endif
 
-static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
+#ifdef CONFIG_PGSTE
+
+/**
+ * gmap_alloc - allocate a guest address space
+ * @mm: pointer to the parent mm_struct
+ *
+ * Returns a guest address space structure.
+ */
+struct gmap *gmap_alloc(struct mm_struct *mm)
 {
-	unsigned int old, new;
+	struct gmap *gmap;
+	struct page *page;
+	unsigned long *table;
 
-	do {
-		old = atomic_read(v);
-		new = old ^ bits;
-	} while (atomic_cmpxchg(v, old, new) != old);
-	return new;
+	gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
+	if (!gmap)
+		goto out;
+	INIT_LIST_HEAD(&gmap->crst_list);
+	gmap->mm = mm;
+	page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+	if (!page)
+		goto out_free;
+	list_add(&page->lru, &gmap->crst_list);
+	table = (unsigned long *) page_to_phys(page);
+	crst_table_init(table, _REGION1_ENTRY_EMPTY);
+	gmap->table = table;
+	list_add(&gmap->list, &mm->context.gmap_list);
+	return gmap;
+
+out_free:
+	kfree(gmap);
+out:
+	return NULL;
 }
+EXPORT_SYMBOL_GPL(gmap_alloc);
 
-/*
- * page table entry allocation/free routines.
+static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table)
+{
+	struct gmap_pgtable *mp;
+	struct gmap_rmap *rmap;
+	struct page *page;
+
+	if (*table & _SEGMENT_ENTRY_INV)
+		return 0;
+	page = pfn_to_page(*table >> PAGE_SHIFT);
+	mp = (struct gmap_pgtable *) page->index;
+	list_for_each_entry(rmap, &mp->mapper, list) {
+		if (rmap->entry != table)
+			continue;
+		list_del(&rmap->list);
+		kfree(rmap);
+		break;
+	}
+	*table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | mp->vmaddr;
+	return 1;
+}
+
+static void gmap_flush_tlb(struct gmap *gmap)
+{
+	if (MACHINE_HAS_IDTE)
+		__tlb_flush_idte((unsigned long) gmap->table |
+				 _ASCE_TYPE_REGION1);
+	else
+		__tlb_flush_global();
+}
+
+/**
+ * gmap_free - free a guest address space
+ * @gmap: pointer to the guest address space structure
  */
-#ifdef CONFIG_PGSTE
-static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm)
+void gmap_free(struct gmap *gmap)
+{
+	struct page *page, *next;
+	unsigned long *table;
+	int i;
+
+
+	/* Flush tlb. */
+	if (MACHINE_HAS_IDTE)
+		__tlb_flush_idte((unsigned long) gmap->table |
+				 _ASCE_TYPE_REGION1);
+	else
+		__tlb_flush_global();
+
+	/* Free all segment & region tables. */
+	down_read(&gmap->mm->mmap_sem);
+	list_for_each_entry_safe(page, next, &gmap->crst_list, lru) {
+		table = (unsigned long *) page_to_phys(page);
+		if ((*table & _REGION_ENTRY_TYPE_MASK) == 0)
+			/* Remove gmap rmap structures for segment table. */
+			for (i = 0; i < PTRS_PER_PMD; i++, table++)
+				gmap_unlink_segment(gmap, table);
+		__free_pages(page, ALLOC_ORDER);
+	}
+	up_read(&gmap->mm->mmap_sem);
+	list_del(&gmap->list);
+	kfree(gmap);
+}
+EXPORT_SYMBOL_GPL(gmap_free);
+
+/**
+ * gmap_enable - switch primary space to the guest address space
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_enable(struct gmap *gmap)
+{
+	/* Load primary space page table origin. */
+	S390_lowcore.user_asce = _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH |
+				 _ASCE_USER_BITS | __pa(gmap->table);
+	asm volatile("lctlg 1,1,%0\n" : : "m" (S390_lowcore.user_asce) );
+	S390_lowcore.gmap = (unsigned long) gmap;
+}
+EXPORT_SYMBOL_GPL(gmap_enable);
+
+/**
+ * gmap_disable - switch back to the standard primary address space
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_disable(struct gmap *gmap)
+{
+	/* Load primary space page table origin. */
+	S390_lowcore.user_asce =
+		gmap->mm->context.asce_bits | __pa(gmap->mm->pgd);
+	asm volatile("lctlg 1,1,%0\n" : : "m" (S390_lowcore.user_asce) );
+	S390_lowcore.gmap = 0UL;
+}
+EXPORT_SYMBOL_GPL(gmap_disable);
+
+static int gmap_alloc_table(struct gmap *gmap,
+			       unsigned long *table, unsigned long init)
+{
+	struct page *page;
+	unsigned long *new;
+
+	page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+	if (!page)
+		return -ENOMEM;
+	new = (unsigned long *) page_to_phys(page);
+	crst_table_init(new, init);
+	down_read(&gmap->mm->mmap_sem);
+	if (*table & _REGION_ENTRY_INV) {
+		list_add(&page->lru, &gmap->crst_list);
+		*table = (unsigned long) new | _REGION_ENTRY_LENGTH |
+			(*table & _REGION_ENTRY_TYPE_MASK);
+	} else
+		__free_pages(page, ALLOC_ORDER);
+	up_read(&gmap->mm->mmap_sem);
+	return 0;
+}
+
+/**
+ * gmap_unmap_segment - unmap segment from the guest address space
+ * @gmap: pointer to the guest address space structure
+ * @addr: address in the guest address space
+ * @len: length of the memory area to unmap
+ *
+ * Returns 0 if the unmap succeded, -EINVAL if not.
+ */
+int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
+{
+	unsigned long *table;
+	unsigned long off;
+	int flush;
+
+	if ((to | len) & (PMD_SIZE - 1))
+		return -EINVAL;
+	if (len == 0 || to + len < to)
+		return -EINVAL;
+
+	flush = 0;
+	down_read(&gmap->mm->mmap_sem);
+	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)
+			return 0;
+		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+		table = table + (((to + off) >> 42) & 0x7ff);
+		if (*table & _REGION_ENTRY_INV)
+			return 0;
+		table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+		table = table + (((to + off) >> 31) & 0x7ff);
+		if (*table & _REGION_ENTRY_INV)
+			return 0;
+		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;
+	}
+	up_read(&gmap->mm->mmap_sem);
+	if (flush)
+		gmap_flush_tlb(gmap);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gmap_unmap_segment);
+
+/**
+ * gmap_mmap_segment - map a segment to the guest address space
+ * @gmap: pointer to the guest address space structure
+ * @from: source address in the parent address space
+ * @to: target address in the guest address space
+ *
+ * Returns 0 if the mmap succeded, -EINVAL or -ENOMEM if not.
+ */
+int gmap_map_segment(struct gmap *gmap, unsigned long from,
+		     unsigned long to, unsigned long len)
+{
+	unsigned long *table;
+	unsigned long off;
+	int flush;
+
+	if ((from | to | len) & (PMD_SIZE - 1))
+		return -EINVAL;
+	if (len == 0 || from + len > PGDIR_SIZE ||
+	    from + len < from || to + len < to)
+		return -EINVAL;
+
+	flush = 0;
+	down_read(&gmap->mm->mmap_sem);
+	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) &&
+		    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) &&
+		    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) &&
+		    gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY))
+			goto out_unmap;
+		table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN);
+		table = table + (((to + off) >> 20) & 0x7ff);
+
+		/* Store 'from' address in an invalid segment table entry. */
+		flush |= gmap_unlink_segment(gmap, table);
+		*table = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO | (from + off);
+	}
+	up_read(&gmap->mm->mmap_sem);
+	if (flush)
+		gmap_flush_tlb(gmap);
+	return 0;
+
+out_unmap:
+	up_read(&gmap->mm->mmap_sem);
+	gmap_unmap_segment(gmap, to, len);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(gmap_map_segment);
+
+unsigned long gmap_fault(unsigned long address, struct gmap *gmap)
+{
+	unsigned long *table, vmaddr, segment;
+	struct mm_struct *mm;
+	struct gmap_pgtable *mp;
+	struct gmap_rmap *rmap;
+	struct vm_area_struct *vma;
+	struct page *page;
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	current->thread.gmap_addr = address;
+	mm = gmap->mm;
+	/* Walk the gmap address space page table */
+	table = gmap->table + ((address >> 53) & 0x7ff);
+	if (unlikely(*table & _REGION_ENTRY_INV))
+		return -EFAULT;
+	table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+	table = table + ((address >> 42) & 0x7ff);
+	if (unlikely(*table & _REGION_ENTRY_INV))
+		return -EFAULT;
+	table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+	table = table + ((address >> 31) & 0x7ff);
+	if (unlikely(*table & _REGION_ENTRY_INV))
+		return -EFAULT;
+	table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+	table = table + ((address >> 20) & 0x7ff);
+
+	/* Convert the gmap address to an mm address. */
+	segment = *table;
+	if (likely(!(segment & _SEGMENT_ENTRY_INV))) {
+		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) {
+		vmaddr = segment & _SEGMENT_ENTRY_ORIGIN;
+		vma = find_vma(mm, vmaddr);
+		if (!vma || vma->vm_start > vmaddr)
+			return -EFAULT;
+
+		/* Walk the parent mm page table */
+		pgd = pgd_offset(mm, vmaddr);
+		pud = pud_alloc(mm, pgd, vmaddr);
+		if (!pud)
+			return -ENOMEM;
+		pmd = pmd_alloc(mm, pud, vmaddr);
+		if (!pmd)
+			return -ENOMEM;
+		if (!pmd_present(*pmd) &&
+		    __pte_alloc(mm, vma, pmd, vmaddr))
+			return -ENOMEM;
+		/* pmd now points to a valid segment table entry. */
+		rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT);
+		if (!rmap)
+			return -ENOMEM;
+		/* Link gmap segment table entry location to page table. */
+		page = pmd_page(*pmd);
+		mp = (struct gmap_pgtable *) page->index;
+		rmap->entry = table;
+		list_add(&rmap->list, &mp->mapper);
+		/* Set gmap segment table entry to page table. */
+		*table = pmd_val(*pmd) & PAGE_MASK;
+		return vmaddr | (address & ~PMD_MASK);
+	}
+	return -EFAULT;
+
+}
+EXPORT_SYMBOL_GPL(gmap_fault);
+
+void gmap_unmap_notifier(struct mm_struct *mm, unsigned long *table)
+{
+	struct gmap_rmap *rmap, *next;
+	struct gmap_pgtable *mp;
+	struct page *page;
+	int flush;
+
+	flush = 0;
+	spin_lock(&mm->page_table_lock);
+	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;
+		list_del(&rmap->list);
+		kfree(rmap);
+		flush = 1;
+	}
+	spin_unlock(&mm->page_table_lock);
+	if (flush)
+		__tlb_flush_global();
+}
+
+static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
+						    unsigned long vmaddr)
 {
 	struct page *page;
 	unsigned long *table;
+	struct gmap_pgtable *mp;
 
 	page = alloc_page(GFP_KERNEL|__GFP_REPEAT);
 	if (!page)
 		return NULL;
+	mp = kmalloc(sizeof(*mp), GFP_KERNEL|__GFP_REPEAT);
+	if (!mp) {
+		__free_page(page);
+		return NULL;
+	}
 	pgtable_page_ctor(page);
+	mp->vmaddr = vmaddr & PMD_MASK;
+	INIT_LIST_HEAD(&mp->mapper);
+	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);
@@ -167,24 +512,57 @@ static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm)
 static inline void page_table_free_pgste(unsigned long *table)
 {
 	struct page *page;
+	struct gmap_pgtable *mp;
 
 	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
+	mp = (struct gmap_pgtable *) page->index;
+	BUG_ON(!list_empty(&mp->mapper));
 	pgtable_page_ctor(page);
 	atomic_set(&page->_mapcount, -1);
+	kfree(mp);
 	__free_page(page);
 }
-#endif
 
-unsigned long *page_table_alloc(struct mm_struct *mm)
+#else /* CONFIG_PGSTE */
+
+static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm,
+						    unsigned long vmaddr)
+{
+}
+
+static inline void page_table_free_pgste(unsigned long *table)
+{
+}
+
+static inline void gmap_unmap_notifier(struct mm_struct *mm,
+					  unsigned long *table)
+{
+}
+
+#endif /* CONFIG_PGSTE */
+
+static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits)
+{
+	unsigned int old, new;
+
+	do {
+		old = atomic_read(v);
+		new = old ^ bits;
+	} while (atomic_cmpxchg(v, old, new) != old);
+	return new;
+}
+
+/*
+ * page table entry allocation/free routines.
+ */
+unsigned long *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr)
 {
 	struct page *page;
 	unsigned long *table;
 	unsigned int mask, bit;
 
-#ifdef CONFIG_PGSTE
 	if (mm_has_pgste(mm))
-		return page_table_alloc_pgste(mm);
-#endif
+		return page_table_alloc_pgste(mm, vmaddr);
 	/* Allocate fragments of a 4K page as 1K/2K page table */
 	spin_lock_bh(&mm->context.list_lock);
 	mask = FRAG_MASK;
@@ -222,10 +600,10 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
 	struct page *page;
 	unsigned int bit, mask;
 
-#ifdef CONFIG_PGSTE
-	if (mm_has_pgste(mm))
+	if (mm_has_pgste(mm)) {
+		gmap_unmap_notifier(mm, table);
 		return page_table_free_pgste(table);
-#endif
+	}
 	/* Free 1K/2K page table fragment of a 4K page */
 	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
 	bit = 1 << ((__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t)));
@@ -249,10 +627,8 @@ static void __page_table_free_rcu(void *table, unsigned bit)
 {
 	struct page *page;
 
-#ifdef CONFIG_PGSTE
 	if (bit == FRAG_MASK)
 		return page_table_free_pgste(table);
-#endif
 	/* Free 1K/2K page table fragment of a 4K page */
 	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
 	if (atomic_xor_bits(&page->_mapcount, bit) == 0) {
@@ -269,13 +645,12 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table)
 	unsigned int bit, mask;
 
 	mm = tlb->mm;
-#ifdef CONFIG_PGSTE
 	if (mm_has_pgste(mm)) {
+		gmap_unmap_notifier(mm, table);
 		table = (unsigned long *) (__pa(table) | FRAG_MASK);
 		tlb_remove_table(tlb, table);
 		return;
 	}
-#endif
 	bit = 1 << ((__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t)));
 	page = pfn_to_page(__pa(table) >> PAGE_SHIFT);
 	spin_lock_bh(&mm->context.list_lock);