arch/nds32/include/asm/mmu_context.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2005-2017 Andes Technology Corporation
   3
   4 #ifndef __ASM_NDS32_MMU_CONTEXT_H
   5 #define __ASM_NDS32_MMU_CONTEXT_H
   6
   7 #include <linux/spinlock.h>
   8 #include <asm/tlbflush.h>
   9 #include <asm/proc-fns.h>
  10 #include <asm-generic/mm_hooks.h>
  11
  12 static inline int
  13 init_new_context(struct task_struct *tsk, struct mm_struct *mm)
  14 {
  15         mm->context.id = 0;
  16         return 0;
  17 }
  18
  19 #define destroy_context(mm)     do { } while(0)
  20
  21 #define CID_BITS        9
  22 extern spinlock_t cid_lock;
  23 extern unsigned int cpu_last_cid;
  24
  25 static inline void __new_context(struct mm_struct *mm)
  26 {
  27         unsigned int cid;
  28         unsigned long flags;
  29
  30         spin_lock_irqsave(&cid_lock, flags);
  31         cid = cpu_last_cid;
  32         cpu_last_cid += 1 << TLB_MISC_offCID;
  33         if (cpu_last_cid == 0)
  34                 cpu_last_cid = 1 << TLB_MISC_offCID << CID_BITS;
  35
  36         if ((cid & TLB_MISC_mskCID) == 0)
  37                 flush_tlb_all();
  38         spin_unlock_irqrestore(&cid_lock, flags);
  39
  40         mm->context.id = cid;
  41 }
  42
  43 static inline void check_context(struct mm_struct *mm)
  44 {
  45         if (unlikely
  46             ((mm->context.id ^ cpu_last_cid) >> TLB_MISC_offCID >> CID_BITS))
  47                 __new_context(mm);
  48 }
  49
  50 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
  51 {
  52 }
  53
  54 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  55                              struct task_struct *tsk)
  56 {
  57         unsigned int cpu = smp_processor_id();
  58
  59         if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next) {
  60                 check_context(next);
  61                 cpu_switch_mm(next);
  62         }
  63 }
  64
  65 #define deactivate_mm(tsk,mm)   do { } while (0)
  66 #define activate_mm(prev,next)  switch_mm(prev, next, NULL)
  67
  68 #endif