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.pgtable_lock); 21 INIT_LIST_HEAD(&mm->context.pgtable_list); 22 spin_lock_init(&mm->context.gmap_lock); 23 INIT_LIST_HEAD(&mm->context.gmap_list); 24 cpumask_clear(&mm->context.cpu_attach_mask); 25 atomic_set(&mm->context.flush_count, 0); 26 mm->context.gmap_asce = 0; 27 mm->context.flush_mm = 0; 28 #ifdef CONFIG_PGSTE 29 mm->context.alloc_pgste = page_table_allocate_pgste || 30 test_thread_flag(TIF_PGSTE) || 31 current->mm->context.alloc_pgste; 32 mm->context.has_pgste = 0; 33 mm->context.use_skey = 0; 34 mm->context.use_cmma = 0; 35 #endif 36 switch (mm->context.asce_limit) { 37 case _REGION2_SIZE: 38 /* 39 * forked 3-level task, fall through to set new asce with new 40 * mm->pgd 41 */ 42 case 0: 43 /* context created by exec, set asce limit to 4TB */ 44 mm->context.asce_limit = STACK_TOP_MAX; 45 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 46 _ASCE_USER_BITS | _ASCE_TYPE_REGION3; 47 break; 48 case -PAGE_SIZE: 49 /* forked 5-level task, set new asce with new_mm->pgd */ 50 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 51 _ASCE_USER_BITS | _ASCE_TYPE_REGION1; 52 break; 53 case _REGION1_SIZE: 54 /* forked 4-level task, set new asce with new mm->pgd */ 55 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 56 _ASCE_USER_BITS | _ASCE_TYPE_REGION2; 57 break; 58 case _REGION3_SIZE: 59 /* forked 2-level compat task, set new asce with new mm->pgd */ 60 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | 61 _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT; 62 /* pgd_alloc() did not increase mm->nr_pmds */ 63 mm_inc_nr_pmds(mm); 64 } 65 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm)); 66 return 0; 67 } 68 69 #define destroy_context(mm) do { } while (0) 70 71 static inline void set_user_asce(struct mm_struct *mm) 72 { 73 S390_lowcore.user_asce = mm->context.asce; 74 if (current->thread.mm_segment.ar4) 75 __ctl_load(S390_lowcore.user_asce, 7, 7); 76 set_cpu_flag(CIF_ASCE_PRIMARY); 77 } 78 79 static inline void clear_user_asce(void) 80 { 81 S390_lowcore.user_asce = S390_lowcore.kernel_asce; 82 83 __ctl_load(S390_lowcore.user_asce, 1, 1); 84 __ctl_load(S390_lowcore.user_asce, 7, 7); 85 } 86 87 static inline void load_kernel_asce(void) 88 { 89 unsigned long asce; 90 91 __ctl_store(asce, 1, 1); 92 if (asce != S390_lowcore.kernel_asce) 93 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 94 set_cpu_flag(CIF_ASCE_PRIMARY); 95 } 96 97 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 98 struct task_struct *tsk) 99 { 100 int cpu = smp_processor_id(); 101 102 S390_lowcore.user_asce = next->context.asce; 103 if (prev == next) 104 return; 105 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask); 106 cpumask_set_cpu(cpu, mm_cpumask(next)); 107 /* Clear old ASCE by loading the kernel ASCE. */ 108 __ctl_load(S390_lowcore.kernel_asce, 1, 1); 109 __ctl_load(S390_lowcore.kernel_asce, 7, 7); 110 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask); 111 } 112 113 #define finish_arch_post_lock_switch finish_arch_post_lock_switch 114 static inline void finish_arch_post_lock_switch(void) 115 { 116 struct task_struct *tsk = current; 117 struct mm_struct *mm = tsk->mm; 118 119 load_kernel_asce(); 120 if (mm) { 121 preempt_disable(); 122 while (atomic_read(&mm->context.flush_count)) 123 cpu_relax(); 124 125 if (mm->context.flush_mm) 126 __tlb_flush_mm(mm); 127 preempt_enable(); 128 } 129 set_fs(current->thread.mm_segment); 130 } 131 132 #define enter_lazy_tlb(mm,tsk) do { } while (0) 133 #define deactivate_mm(tsk,mm) do { } while (0) 134 135 static inline void activate_mm(struct mm_struct *prev, 136 struct mm_struct *next) 137 { 138 switch_mm(prev, next, current); 139 set_user_asce(next); 140 } 141 142 #endif /* __S390_MMU_CONTEXT_H */ 143