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 15 static inline int init_new_context(struct task_struct *tsk, 16 struct mm_struct *mm) 17 { 18 atomic_set(&mm->context.attach_count, 0); 19 mm->context.flush_mm = 0; 20 mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS; 21 #ifdef CONFIG_64BIT 22 mm->context.asce_bits |= _ASCE_TYPE_REGION3; 23 #endif 24 if (current->mm && current->mm->context.alloc_pgste) { 25 /* 26 * alloc_pgste indicates, that any NEW context will be created 27 * with extended page tables. The old context is unchanged. The 28 * page table allocation and the page table operations will 29 * look at has_pgste to distinguish normal and extended page 30 * tables. The only way to create extended page tables is to 31 * set alloc_pgste and then create a new context (e.g. dup_mm). 32 * The page table allocation is called after init_new_context 33 * and if has_pgste is set, it will create extended page 34 * tables. 35 */ 36 mm->context.has_pgste = 1; 37 mm->context.alloc_pgste = 1; 38 } else { 39 mm->context.has_pgste = 0; 40 mm->context.alloc_pgste = 0; 41 } 42 mm->context.asce_limit = STACK_TOP_MAX; 43 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); 44 return 0; 45 } 46 47 #define destroy_context(mm) do { } while (0) 48 49 #ifndef CONFIG_64BIT 50 #define LCTL_OPCODE "lctl" 51 #else 52 #define LCTL_OPCODE "lctlg" 53 #endif 54 55 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk) 56 { 57 pgd_t *pgd = mm->pgd; 58 59 S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd); 60 if (s390_user_mode != HOME_SPACE_MODE) { 61 /* Load primary space page table origin. */ 62 asm volatile(LCTL_OPCODE" 1,1,%0\n" 63 : : "m" (S390_lowcore.user_asce) ); 64 } else 65 /* Load home space page table origin. */ 66 asm volatile(LCTL_OPCODE" 13,13,%0" 67 : : "m" (S390_lowcore.user_asce) ); 68 set_fs(current->thread.mm_segment); 69 } 70 71 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 72 struct task_struct *tsk) 73 { 74 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); 75 update_mm(next, tsk); 76 atomic_dec(&prev->context.attach_count); 77 WARN_ON(atomic_read(&prev->context.attach_count) < 0); 78 atomic_inc(&next->context.attach_count); 79 /* Check for TLBs not flushed yet */ 80 if (next->context.flush_mm) 81 __tlb_flush_mm(next); 82 } 83 84 #define enter_lazy_tlb(mm,tsk) do { } while (0) 85 #define deactivate_mm(tsk,mm) do { } while (0) 86 87 static inline void activate_mm(struct mm_struct *prev, 88 struct mm_struct *next) 89 { 90 switch_mm(prev, next, current); 91 } 92 93 static inline void arch_dup_mmap(struct mm_struct *oldmm, 94 struct mm_struct *mm) 95 { 96 #ifdef CONFIG_64BIT 97 if (oldmm->context.asce_limit < mm->context.asce_limit) 98 crst_table_downgrade(mm, oldmm->context.asce_limit); 99 #endif 100 } 101 102 static inline void arch_exit_mmap(struct mm_struct *mm) 103 { 104 } 105 106 #endif /* __S390_MMU_CONTEXT_H */ 107