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 cpumask_clear(&mm->context.cpu_attach_mask); 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 mm->context.asce_bits |= _ASCE_TYPE_REGION3; 23 #ifdef CONFIG_PGSTE 24 mm->context.alloc_pgste = page_table_allocate_pgste; 25 mm->context.has_pgste = 0; 26 mm->context.use_skey = 0; 27 #endif 28 mm->context.asce_limit = STACK_TOP_MAX; 29 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); 30 return 0; 31 } 32 33 #define destroy_context(mm) do { } while (0) 34 35 static inline void set_user_asce(struct mm_struct *mm) 36 { 37 S390_lowcore.user_asce = mm->context.asce_bits | __pa(mm->pgd); 38 if (current->thread.mm_segment.ar4) 39 __ctl_load(S390_lowcore.user_asce, 7, 7); 40 set_cpu_flag(CIF_ASCE); 41 } 42 43 static inline void clear_user_asce(void) 44 { 45 S390_lowcore.user_asce = S390_lowcore.kernel_asce; 46 47 __ctl_load(S390_lowcore.user_asce, 1, 1); 48 __ctl_load(S390_lowcore.user_asce, 7, 7); 49 } 50 51 static inline void load_kernel_asce(void) 52 { 53 unsigned long asce; 54 55 __ctl_store(asce, 1, 1); 56 if (asce != S390_lowcore.kernel_asce) 57 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 58 set_cpu_flag(CIF_ASCE); 59 } 60 61 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 62 struct task_struct *tsk) 63 { 64 int cpu = smp_processor_id(); 65 66 S390_lowcore.user_asce = next->context.asce_bits | __pa(next->pgd); 67 if (prev == next) 68 return; 69 if (MACHINE_HAS_TLB_LC) 70 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask); 71 /* Clear old ASCE by loading the kernel ASCE. */ 72 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 73 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 74 atomic_inc(&next->context.attach_count); 75 atomic_dec(&prev->context.attach_count); 76 if (MACHINE_HAS_TLB_LC) 77 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask); 78 } 79 80 #define finish_arch_post_lock_switch finish_arch_post_lock_switch 81 static inline void finish_arch_post_lock_switch(void) 82 { 83 struct task_struct *tsk = current; 84 struct mm_struct *mm = tsk->mm; 85 86 load_kernel_asce(); 87 if (mm) { 88 preempt_disable(); 89 while (atomic_read(&mm->context.attach_count) >> 16) 90 cpu_relax(); 91 92 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm)); 93 if (mm->context.flush_mm) 94 __tlb_flush_mm(mm); 95 preempt_enable(); 96 } 97 set_fs(current->thread.mm_segment); 98 } 99 100 #define enter_lazy_tlb(mm,tsk) do { } while (0) 101 #define deactivate_mm(tsk,mm) do { } while (0) 102 103 static inline void activate_mm(struct mm_struct *prev, 104 struct mm_struct *next) 105 { 106 switch_mm(prev, next, current); 107 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); 108 set_user_asce(next); 109 } 110 111 static inline void arch_dup_mmap(struct mm_struct *oldmm, 112 struct mm_struct *mm) 113 { 114 if (oldmm->context.asce_limit < mm->context.asce_limit) 115 crst_table_downgrade(mm, oldmm->context.asce_limit); 116 } 117 118 static inline void arch_exit_mmap(struct mm_struct *mm) 119 { 120 } 121 122 static inline void arch_unmap(struct mm_struct *mm, 123 struct vm_area_struct *vma, 124 unsigned long start, unsigned long end) 125 { 126 } 127 128 static inline void arch_bprm_mm_init(struct mm_struct *mm, 129 struct vm_area_struct *vma) 130 { 131 } 132 133 #endif /* __S390_MMU_CONTEXT_H */ 134