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: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h
index 3525fe6..3f46a65 100644
--- a/arch/s390/include/asm/mmu.h
+++ b/arch/s390/include/asm/mmu.h
@@ -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)
diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index 484efe8..3c9abed 100644
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -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);
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 9e1494e..2f66290 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -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);
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 05b5b1b..05f1f27 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -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);
}
