Commit f28a4b4d authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/mm: use a single lock for the fields in mm_context_t 



The three locks 'lock', 'pgtable_lock' and 'gmap_lock' in the
mm_context_t can be reduced to a single lock.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 60f07c8e

arch/s390/include/asm/mmu.h

+0 −5
Original line number Diff line number Diff line
@@ -9,9 +9,7 @@ typedef struct { 
	cpumask_t cpu_attach_mask;

	atomic_t flush_count;

	unsigned int flush_mm;

	spinlock_t pgtable_lock;

	struct list_head pgtable_list;

	spinlock_t gmap_lock;

	struct list_head gmap_list;

	unsigned long gmap_asce;

	unsigned long asce;
@@ -29,10 +27,7 @@ typedef struct { 


#define INIT_MM_CONTEXT(name)						   \

	.context.lock =	__SPIN_LOCK_UNLOCKED(name.context.lock),	   \

	.context.pgtable_lock =						   \

			__SPIN_LOCK_UNLOCKED(name.context.pgtable_lock),   \

	.context.pgtable_list = LIST_HEAD_INIT(name.context.pgtable_list), \

	.context.gmap_lock = __SPIN_LOCK_UNLOCKED(name.context.gmap_lock), \

	.context.gmap_list = LIST_HEAD_INIT(name.context.gmap_list),



static inline int tprot(unsigned long addr)

arch/s390/include/asm/mmu_context.h

+0 −2
Original line number Diff line number Diff line
@@ -18,9 +18,7 @@ static inline int init_new_context(struct task_struct *tsk, 
				   struct mm_struct *mm)

{

	spin_lock_init(&mm->context.lock);

	spin_lock_init(&mm->context.pgtable_lock);

	INIT_LIST_HEAD(&mm->context.pgtable_list);

	spin_lock_init(&mm->context.gmap_lock);

	INIT_LIST_HEAD(&mm->context.gmap_list);

	cpumask_clear(&mm->context.cpu_attach_mask);

	atomic_set(&mm->context.flush_count, 0);

arch/s390/mm/gmap.c

+4 −4
Original line number Diff line number Diff line
@@ -100,14 +100,14 @@ struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit) 
	if (!gmap)

		return NULL;

	gmap->mm = mm;

	spin_lock(&mm->context.gmap_lock);

	spin_lock(&mm->context.lock);

	list_add_rcu(&gmap->list, &mm->context.gmap_list);

	if (list_is_singular(&mm->context.gmap_list))

		gmap_asce = gmap->asce;

	else

		gmap_asce = -1UL;

	WRITE_ONCE(mm->context.gmap_asce, gmap_asce);

	spin_unlock(&mm->context.gmap_lock);

	spin_unlock(&mm->context.lock);

	return gmap;

}

EXPORT_SYMBOL_GPL(gmap_create);
@@ -248,7 +248,7 @@ void gmap_remove(struct gmap *gmap) 
		spin_unlock(&gmap->shadow_lock);

	}

	/* Remove gmap from the pre-mm list */

	spin_lock(&gmap->mm->context.gmap_lock);

	spin_lock(&gmap->mm->context.lock);

	list_del_rcu(&gmap->list);

	if (list_empty(&gmap->mm->context.gmap_list))

		gmap_asce = 0;
@@ -258,7 +258,7 @@ void gmap_remove(struct gmap *gmap) 
	else

		gmap_asce = -1UL;

	WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);

	spin_unlock(&gmap->mm->context.gmap_lock);

	spin_unlock(&gmap->mm->context.lock);

	synchronize_rcu();

	/* Put reference */

	gmap_put(gmap);

arch/s390/mm/pgalloc.c

+8 −8
Original line number Diff line number Diff line
@@ -188,7 +188,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm) 
	/* Try to get a fragment of a 4K page as a 2K page table */

	if (!mm_alloc_pgste(mm)) {

		table = NULL;

		spin_lock_bh(&mm->context.pgtable_lock);

		spin_lock_bh(&mm->context.lock);

		if (!list_empty(&mm->context.pgtable_list)) {

			page = list_first_entry(&mm->context.pgtable_list,

						struct page, lru);
@@ -203,7 +203,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm) 
				list_del(&page->lru);

			}

		}

		spin_unlock_bh(&mm->context.pgtable_lock);

		spin_unlock_bh(&mm->context.lock);

		if (table)

			return table;

	}
@@ -227,9 +227,9 @@ unsigned long *page_table_alloc(struct mm_struct *mm) 
		/* Return the first 2K fragment of the page */

		atomic_set(&page->_mapcount, 1);

		clear_table(table, _PAGE_INVALID, PAGE_SIZE);

		spin_lock_bh(&mm->context.pgtable_lock);

		spin_lock_bh(&mm->context.lock);

		list_add(&page->lru, &mm->context.pgtable_list);

		spin_unlock_bh(&mm->context.pgtable_lock);

		spin_unlock_bh(&mm->context.lock);

	}

	return table;

}
@@ -243,13 +243,13 @@ void page_table_free(struct mm_struct *mm, unsigned long *table) 
	if (!mm_alloc_pgste(mm)) {

		/* Free 2K page table fragment of a 4K page */

		bit = (__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t));

		spin_lock_bh(&mm->context.pgtable_lock);

		spin_lock_bh(&mm->context.lock);

		mask = atomic_xor_bits(&page->_mapcount, 1U << bit);

		if (mask & 3)

			list_add(&page->lru, &mm->context.pgtable_list);

		else

			list_del(&page->lru);

		spin_unlock_bh(&mm->context.pgtable_lock);

		spin_unlock_bh(&mm->context.lock);

		if (mask != 0)

			return;

	}
@@ -275,13 +275,13 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table, 
		return;

	}

	bit = (__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t));

	spin_lock_bh(&mm->context.pgtable_lock);

	spin_lock_bh(&mm->context.lock);

	mask = atomic_xor_bits(&page->_mapcount, 0x11U << bit);

	if (mask & 3)

		list_add_tail(&page->lru, &mm->context.pgtable_list);

	else

		list_del(&page->lru);

	spin_unlock_bh(&mm->context.pgtable_lock);

	spin_unlock_bh(&mm->context.lock);

	table = (unsigned long *) (__pa(table) | (1U << bit));

	tlb_remove_table(tlb, table);

}