Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / arch / s390 / mm / pgtable.c

diff --git a/kernel/arch/s390/mm/pgtable.c b/kernel/arch/s390/mm/pgtable.c
index 54ef3bc..8345ae1 100644 (file)
--- a/kernel/arch/s390/mm/pgtable.c
+++ b/kernel/arch/s390/mm/pgtable.c
@@ -49,81 +49,52 @@ static void __crst_table_upgrade(void *arg)
        __tlb_flush_local();
 }
 
-int crst_table_upgrade(struct mm_struct *mm, unsigned long limit)
+int crst_table_upgrade(struct mm_struct *mm)
 {
        unsigned long *table, *pgd;
-       unsigned long entry;
-       int flush;
 
-       BUG_ON(limit > (1UL << 53));
-       flush = 0;
-repeat:
+       /* upgrade should only happen from 3 to 4 levels */
+       BUG_ON(mm->context.asce_limit != (1UL << 42));
+
        table = crst_table_alloc(mm);
        if (!table)
                return -ENOMEM;
+
        spin_lock_bh(&mm->page_table_lock);
-       if (mm->context.asce_limit < limit) {
-               pgd = (unsigned long *) mm->pgd;
-               if (mm->context.asce_limit <= (1UL << 31)) {
-                       entry = _REGION3_ENTRY_EMPTY;
-                       mm->context.asce_limit = 1UL << 42;
-                       mm->context.asce_bits = _ASCE_TABLE_LENGTH |
-                                               _ASCE_USER_BITS |
-                                               _ASCE_TYPE_REGION3;
-               } else {
-                       entry = _REGION2_ENTRY_EMPTY;
-                       mm->context.asce_limit = 1UL << 53;
-                       mm->context.asce_bits = _ASCE_TABLE_LENGTH |
-                                               _ASCE_USER_BITS |
-                                               _ASCE_TYPE_REGION2;
-               }
-               crst_table_init(table, entry);
-               pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
-               mm->pgd = (pgd_t *) table;
-               mm->task_size = mm->context.asce_limit;
-               table = NULL;
-               flush = 1;
-       }
+       pgd = (unsigned long *) mm->pgd;
+       crst_table_init(table, _REGION2_ENTRY_EMPTY);
+       pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd);
+       mm->pgd = (pgd_t *) table;
+       mm->context.asce_limit = 1UL << 53;
+       mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
+                          _ASCE_USER_BITS | _ASCE_TYPE_REGION2;
+       mm->task_size = mm->context.asce_limit;
        spin_unlock_bh(&mm->page_table_lock);
-       if (table)
-               crst_table_free(mm, table);
-       if (mm->context.asce_limit < limit)
-               goto repeat;
-       if (flush)
-               on_each_cpu(__crst_table_upgrade, mm, 0);
+
+       on_each_cpu(__crst_table_upgrade, mm, 0);
        return 0;
 }
 
-void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
+void crst_table_downgrade(struct mm_struct *mm)
 {
        pgd_t *pgd;
 
+       /* downgrade should only happen from 3 to 2 levels (compat only) */
+       BUG_ON(mm->context.asce_limit != (1UL << 42));
+
        if (current->active_mm == mm) {
                clear_user_asce();
                __tlb_flush_mm(mm);
        }
-       while (mm->context.asce_limit > limit) {
-               pgd = mm->pgd;
-               switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) {
-               case _REGION_ENTRY_TYPE_R2:
-                       mm->context.asce_limit = 1UL << 42;
-                       mm->context.asce_bits = _ASCE_TABLE_LENGTH |
-                                               _ASCE_USER_BITS |
-                                               _ASCE_TYPE_REGION3;
-                       break;
-               case _REGION_ENTRY_TYPE_R3:
-                       mm->context.asce_limit = 1UL << 31;
-                       mm->context.asce_bits = _ASCE_TABLE_LENGTH |
-                                               _ASCE_USER_BITS |
-                                               _ASCE_TYPE_SEGMENT;
-                       break;
-               default:
-                       BUG();
-               }
-               mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
-               mm->task_size = mm->context.asce_limit;
-               crst_table_free(mm, (unsigned long *) pgd);
-       }
+
+       pgd = mm->pgd;
+       mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN);
+       mm->context.asce_limit = 1UL << 31;
+       mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
+                          _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT;
+       mm->task_size = mm->context.asce_limit;
+       crst_table_free(mm, (unsigned long *) pgd);
+
        if (current->active_mm == mm)
                set_user_asce(mm);
 }
@@ -195,7 +166,7 @@ EXPORT_SYMBOL_GPL(gmap_alloc);
 static void gmap_flush_tlb(struct gmap *gmap)
 {
        if (MACHINE_HAS_IDTE)
-               __tlb_flush_asce(gmap->mm, gmap->asce);
+               __tlb_flush_idte(gmap->asce);
        else
                __tlb_flush_global();
 }
@@ -234,7 +205,7 @@ void gmap_free(struct gmap *gmap)
 
        /* Flush tlb. */
        if (MACHINE_HAS_IDTE)
-               __tlb_flush_asce(gmap->mm, gmap->asce);
+               __tlb_flush_idte(gmap->asce);
        else
                __tlb_flush_global();