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 <linux/uaccess.h> 12 #include <linux/mm_types.h> 13 #include <asm/tlbflush.h> 14 #include <asm/ctl_reg.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 spin_lock_init(&mm->context.lock); 21 INIT_LIST_HEAD(&mm->context.pgtable_list); 22 INIT_LIST_HEAD(&mm->context.gmap_list); 23 cpumask_clear(&mm->context.cpu_attach_mask); 24 atomic_set(&mm->context.flush_count, 0); 25 mm->context.gmap_asce = 0; 26 mm->context.flush_mm = 0; 27 #ifdef CONFIG_PGSTE 28 mm->context.alloc_pgste = page_table_allocate_pgste || 29 test_thread_flag(TIF_PGSTE) || 30 current->mm->context.alloc_pgste; 31 mm->context.has_pgste = 0; 32 mm->context.use_skey = 0; 33 mm->context.use_cmma = 0; 34 #endif 35 switch (mm->context.asce_limit) { 36 case _REGION2_SIZE: 37 /* 38 * forked 3-level task, fall through to set new asce with new 39 * mm->pgd 40 */ 41 case 0: 42 /* context created by exec, set asce limit to 4TB */ 43 mm->context.asce_limit = STACK_TOP_MAX; 44 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 45 _ASCE_USER_BITS | _ASCE_TYPE_REGION3; 46 break; 47 case -PAGE_SIZE: 48 /* forked 5-level task, set new asce with new_mm->pgd */ 49 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 50 _ASCE_USER_BITS | _ASCE_TYPE_REGION1; 51 break; 52 case _REGION1_SIZE: 53 /* forked 4-level task, set new asce with new mm->pgd */ 54 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 55 _ASCE_USER_BITS | _ASCE_TYPE_REGION2; 56 break; 57 case _REGION3_SIZE: 58 /* forked 2-level compat task, set new asce with new mm->pgd */ 59 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 60 _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT; 61 /* pgd_alloc() did not increase mm->nr_pmds */ 62 mm_inc_nr_pmds(mm); 63 } 64 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); 65 return 0; 66 } 67 68 #define destroy_context(mm) do { } while (0) 69 70 static inline void set_user_asce(struct mm_struct *mm) 71 { 72 S390_lowcore.user_asce = mm->context.asce; 73 if (current->thread.mm_segment.ar4) 74 __ctl_load(S390_lowcore.user_asce, 7, 7); 75 set_cpu_flag(CIF_ASCE_PRIMARY); 76 } 77 78 static inline void clear_user_asce(void) 79 { 80 S390_lowcore.user_asce = S390_lowcore.kernel_asce; 81 82 __ctl_load(S390_lowcore.user_asce, 1, 1); 83 __ctl_load(S390_lowcore.user_asce, 7, 7); 84 } 85 86 static inline void load_kernel_asce(void) 87 { 88 unsigned long asce; 89 90 __ctl_store(asce, 1, 1); 91 if (asce != S390_lowcore.kernel_asce) 92 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 93 set_cpu_flag(CIF_ASCE_PRIMARY); 94 } 95 96 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 97 struct task_struct *tsk) 98 { 99 int cpu = smp_processor_id(); 100 101 S390_lowcore.user_asce = next->context.asce; 102 if (prev == next) 103 return; 104 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask); 105 /* Clear old ASCE by loading the kernel ASCE. */ 106 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 107 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 108 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask); 109 } 110 111 #define finish_arch_post_lock_switch finish_arch_post_lock_switch 112 static inline void finish_arch_post_lock_switch(void) 113 { 114 struct task_struct *tsk = current; 115 struct mm_struct *mm = tsk->mm; 116 117 load_kernel_asce(); 118 if (mm) { 119 preempt_disable(); 120 while (atomic_read(&mm->context.flush_count)) 121 cpu_relax(); 122 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm)); 123 __tlb_flush_mm_lazy(mm); 124 preempt_enable(); 125 } 126 set_fs(current->thread.mm_segment); 127 } 128 129 #define enter_lazy_tlb(mm,tsk) do { } while (0) 130 #define deactivate_mm(tsk,mm) do { } while (0) 131 132 static inline void activate_mm(struct mm_struct *prev, 133 struct mm_struct *next) 134 { 135 switch_mm(prev, next, current); 136 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); 137 set_user_asce(next); 138 } 139 140 #endif /* __S390_MMU_CONTEXT_H */ 141