1 /* 2 * include/asm-s390/mmu_context.h 3 * 4 * S390 version 5 * 6 * Derived from "include/asm-i386/mmu_context.h" 7 */ 8 9 #ifndef __S390_MMU_CONTEXT_H 10 #define __S390_MMU_CONTEXT_H 11 12 #include <asm/pgalloc.h> 13 #include <asm/uaccess.h> 14 #include <asm/tlbflush.h> 15 #include <asm-generic/mm_hooks.h> 16 17 static inline int init_new_context(struct task_struct *tsk, 18 struct mm_struct *mm) 19 { 20 atomic_set(&mm->context.attach_count, 0); 21 mm->context.flush_mm = 0; 22 mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS; 23 #ifdef CONFIG_64BIT 24 mm->context.asce_bits |= _ASCE_TYPE_REGION3; 25 #endif 26 if (current->mm && current->mm->context.alloc_pgste) { 27 /* 28 * alloc_pgste indicates, that any NEW context will be created 29 * with extended page tables. The old context is unchanged. The 30 * page table allocation and the page table operations will 31 * look at has_pgste to distinguish normal and extended page 32 * tables. The only way to create extended page tables is to 33 * set alloc_pgste and then create a new context (e.g. dup_mm). 34 * The page table allocation is called after init_new_context 35 * and if has_pgste is set, it will create extended page 36 * tables. 37 */ 38 mm->context.has_pgste = 1; 39 mm->context.alloc_pgste = 1; 40 } else { 41 mm->context.has_pgste = 0; 42 mm->context.alloc_pgste = 0; 43 } 44 mm->context.asce_limit = STACK_TOP_MAX; 45 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); 46 return 0; 47 } 48 49 #define destroy_context(mm) do { } while (0) 50 51 #ifndef __s390x__ 52 #define LCTL_OPCODE "lctl" 53 #else 54 #define LCTL_OPCODE "lctlg" 55 #endif 56 57 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk) 58 { 59 pgd_t *pgd = mm->pgd; 60 61 S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd); 62 if (user_mode != HOME_SPACE_MODE) { 63 /* Load primary space page table origin. */ 64 asm volatile(LCTL_OPCODE" 1,1,%0\n" 65 : : "m" (S390_lowcore.user_asce) ); 66 } else 67 /* Load home space page table origin. */ 68 asm volatile(LCTL_OPCODE" 13,13,%0" 69 : : "m" (S390_lowcore.user_asce) ); 70 set_fs(current->thread.mm_segment); 71 } 72 73 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 74 struct task_struct *tsk) 75 { 76 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); 77 update_mm(next, tsk); 78 atomic_dec(&prev->context.attach_count); 79 WARN_ON(atomic_read(&prev->context.attach_count) < 0); 80 atomic_inc(&next->context.attach_count); 81 /* Check for TLBs not flushed yet */ 82 if (next->context.flush_mm) 83 __tlb_flush_mm(next); 84 } 85 86 #define enter_lazy_tlb(mm,tsk) do { } while (0) 87 #define deactivate_mm(tsk,mm) do { } while (0) 88 89 static inline void activate_mm(struct mm_struct *prev, 90 struct mm_struct *next) 91 { 92 switch_mm(prev, next, current); 93 } 94 95 #endif /* __S390_MMU_CONTEXT_H */ 96