LXR linux/arch/s390/include/asm/mmu

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 *  S390 version
   4 *
   5 *  Derived from "include/asm-i386/mmu_context.h"
   6 */
   7
   8#ifndef __S390_MMU_CONTEXT_H
   9#define __S390_MMU_CONTEXT_H
  10
  11#include <asm/pgalloc.h>
  12#include <linux/uaccess.h>
  13#include <linux/mm_types.h>
  14#include <asm/tlbflush.h>
  15#include <asm/ctl_reg.h>
  16#include <asm-generic/mm_hooks.h>
  17
  18#define init_new_context init_new_context
  19static inline int init_new_context(struct task_struct *tsk,
  20                                   struct mm_struct *mm)
  21{
  22        unsigned long asce_type, init_entry;
  23
  24        spin_lock_init(&mm->context.lock);
  25        INIT_LIST_HEAD(&mm->context.pgtable_list);
  26        INIT_LIST_HEAD(&mm->context.gmap_list);
  27        cpumask_clear(&mm->context.cpu_attach_mask);
  28        atomic_set(&mm->context.flush_count, 0);
  29        atomic_set(&mm->context.is_protected, 0);
  30        mm->context.gmap_asce = 0;
  31        mm->context.flush_mm = 0;
  32#ifdef CONFIG_PGSTE
  33        mm->context.alloc_pgste = page_table_allocate_pgste ||
  34                test_thread_flag(TIF_PGSTE) ||
  35                (current->mm && current->mm->context.alloc_pgste);
  36        mm->context.has_pgste = 0;
  37        mm->context.uses_skeys = 0;
  38        mm->context.uses_cmm = 0;
  39        mm->context.allow_gmap_hpage_1m = 0;
  40#endif
  41        switch (mm->context.asce_limit) {
  42        default:
  43                /*
  44                 * context created by exec, the value of asce_limit can
  45                 * only be zero in this case
  46                 */
  47                VM_BUG_ON(mm->context.asce_limit);
  48                /* continue as 3-level task */
  49                mm->context.asce_limit = _REGION2_SIZE;
  50                fallthrough;
  51        case _REGION2_SIZE:
  52                /* forked 3-level task */
  53                init_entry = _REGION3_ENTRY_EMPTY;
  54                asce_type = _ASCE_TYPE_REGION3;
  55                break;
  56        case TASK_SIZE_MAX:
  57                /* forked 5-level task */
  58                init_entry = _REGION1_ENTRY_EMPTY;
  59                asce_type = _ASCE_TYPE_REGION1;
  60                break;
  61        case _REGION1_SIZE:
  62                /* forked 4-level task */
  63                init_entry = _REGION2_ENTRY_EMPTY;
  64                asce_type = _ASCE_TYPE_REGION2;
  65                break;
  66        }
  67        mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
  68                           _ASCE_USER_BITS | asce_type;
  69        crst_table_init((unsigned long *) mm->pgd, init_entry);
  70        return 0;
  71}
  72
  73static inline void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
  74                                      struct task_struct *tsk)
  75{
  76        int cpu = smp_processor_id();
  77
  78        if (next == &init_mm)
  79                S390_lowcore.user_asce = s390_invalid_asce;
  80        else
  81                S390_lowcore.user_asce = next->context.asce;
  82        cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
  83        /* Clear previous user-ASCE from CR7 */
  84        __ctl_load(s390_invalid_asce, 7, 7);
  85        if (prev != next)
  86                cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
  87}
  88#define switch_mm_irqs_off switch_mm_irqs_off
  89
  90static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  91                             struct task_struct *tsk)
  92{
  93        unsigned long flags;
  94
  95        local_irq_save(flags);
  96        switch_mm_irqs_off(prev, next, tsk);
  97        local_irq_restore(flags);
  98}
  99
 100#define finish_arch_post_lock_switch finish_arch_post_lock_switch
 101static inline void finish_arch_post_lock_switch(void)
 102{
 103        struct task_struct *tsk = current;
 104        struct mm_struct *mm = tsk->mm;
 105
 106        if (mm) {
 107                preempt_disable();
 108                while (atomic_read(&mm->context.flush_count))
 109                        cpu_relax();
 110                cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
 111                __tlb_flush_mm_lazy(mm);
 112                preempt_enable();
 113        }
 114        __ctl_load(S390_lowcore.user_asce, 7, 7);
 115}
 116
 117#define activate_mm activate_mm
 118static inline void activate_mm(struct mm_struct *prev,
 119                               struct mm_struct *next)
 120{
 121        switch_mm(prev, next, current);
 122        cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
 123        __ctl_load(S390_lowcore.user_asce, 7, 7);
 124}
 125
 126#include <asm-generic/mmu_context.h>
 127
 128#endif /* __S390_MMU_CONTEXT_H */
 129