1 /* 2 * S390 version 3 * 4 * Derived from "include/asm-i386/mmu_context.h" 5 */ 6 7 #ifndef __S390_MMU_CONTEXT_H 8 #define __S390_MMU_CONTEXT_H 9 10 #include <asm/pgalloc.h> 11 #include <asm/uaccess.h> 12 #include <asm/tlbflush.h> 13 #include <asm/ctl_reg.h> 14 #include <asm-generic/mm_hooks.h> 15 16 static inline int init_new_context(struct task_struct *tsk, 17 struct mm_struct *mm) 18 { 19 atomic_set(&mm->context.attach_count, 0); 20 mm->context.flush_mm = 0; 21 mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS; 22 #ifdef CONFIG_64BIT 23 mm->context.asce_bits |= _ASCE_TYPE_REGION3; 24 #endif 25 if (current->mm && current->mm->context.alloc_pgste) { 26 /* 27 * alloc_pgste indicates, that any NEW context will be created 28 * with extended page tables. The old context is unchanged. The 29 * page table allocation and the page table operations will 30 * look at has_pgste to distinguish normal and extended page 31 * tables. The only way to create extended page tables is to 32 * set alloc_pgste and then create a new context (e.g. dup_mm). 33 * The page table allocation is called after init_new_context 34 * and if has_pgste is set, it will create extended page 35 * tables. 36 */ 37 mm->context.has_pgste = 1; 38 mm->context.alloc_pgste = 1; 39 } else { 40 mm->context.has_pgste = 0; 41 mm->context.alloc_pgste = 0; 42 } 43 mm->context.asce_limit = STACK_TOP_MAX; 44 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); 45 return 0; 46 } 47 48 #define destroy_context(mm) do { } while (0) 49 50 #ifndef CONFIG_64BIT 51 #define LCTL_OPCODE "lctl" 52 #else 53 #define LCTL_OPCODE "lctlg" 54 #endif 55 56 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk) 57 { 58 pgd_t *pgd = mm->pgd; 59 60 S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd); 61 if (user_mode != HOME_SPACE_MODE) { 62 /* Load primary space page table origin. */ 63 asm volatile(LCTL_OPCODE" 1,1,%0\n" 64 : : "m" (S390_lowcore.user_asce) ); 65 } else 66 /* Load home space page table origin. */ 67 asm volatile(LCTL_OPCODE" 13,13,%0" 68 : : "m" (S390_lowcore.user_asce) ); 69 set_fs(current->thread.mm_segment); 70 } 71 72 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 73 struct task_struct *tsk) 74 { 75 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); 76 update_mm(next, tsk); 77 atomic_dec(&prev->context.attach_count); 78 WARN_ON(atomic_read(&prev->context.attach_count) < 0); 79 atomic_inc(&next->context.attach_count); 80 /* Check for TLBs not flushed yet */ 81 if (next->context.flush_mm) 82 __tlb_flush_mm(next); 83 } 84 85 #define enter_lazy_tlb(mm,tsk) do { } while (0) 86 #define deactivate_mm(tsk,mm) do { } while (0) 87 88 static inline void activate_mm(struct mm_struct *prev, 89 struct mm_struct *next) 90 { 91 switch_mm(prev, next, current); 92 } 93 94 #endif /* __S390_MMU_CONTEXT_H */ 95