arch/unicore32/include/asm/mmu_context.h

   1 /*
   2  * linux/arch/unicore32/include/asm/mmu_context.h
   3  *
   4  * Code specific to PKUnity SoC and UniCore ISA
   5  *
   6  * Copyright (C) 2001-2010 GUAN Xue-tao
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #ifndef __UNICORE_MMU_CONTEXT_H__
  13 #define __UNICORE_MMU_CONTEXT_H__
  14
  15 #include <linux/compiler.h>
  16 #include <linux/sched.h>
  17 #include <linux/io.h>
  18
  19 #include <asm/cacheflush.h>
  20 #include <asm/cpu-single.h>
  21
  22 #define init_new_context(tsk, mm)       0
  23
  24 #define destroy_context(mm)             do { } while (0)
  25
  26 /*
  27  * This is called when "tsk" is about to enter lazy TLB mode.
  28  *
  29  * mm:  describes the currently active mm context
  30  * tsk: task which is entering lazy tlb
  31  * cpu: cpu number which is entering lazy tlb
  32  *
  33  * tsk->mm will be NULL
  34  */
  35 static inline void
  36 enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
  37 {
  38 }
  39
  40 /*
  41  * This is the actual mm switch as far as the scheduler
  42  * is concerned.  No registers are touched.  We avoid
  43  * calling the CPU specific function when the mm hasn't
  44  * actually changed.
  45  */
  46 static inline void
  47 switch_mm(struct mm_struct *prev, struct mm_struct *next,
  48           struct task_struct *tsk)
  49 {
  50         unsigned int cpu = smp_processor_id();
  51
  52         if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next)
  53                 cpu_switch_mm(next->pgd, next);
  54 }
  55
  56 #define deactivate_mm(tsk, mm)  do { } while (0)
  57 #define activate_mm(prev, next) switch_mm(prev, next, NULL)
  58
  59 /*
  60  * We are inserting a "fake" vma for the user-accessible vector page so
  61  * gdb and friends can get to it through ptrace and /proc/<pid>/mem.
  62  * But we also want to remove it before the generic code gets to see it
  63  * during process exit or the unmapping of it would  cause total havoc.
  64  * (the macro is used as remove_vma() is static to mm/mmap.c)
  65  */
  66 #define arch_exit_mmap(mm) \
  67 do { \
  68         struct vm_area_struct *high_vma = find_vma(mm, 0xffff0000); \
  69         if (high_vma) { \
  70                 BUG_ON(high_vma->vm_next);  /* it should be last */ \
  71                 if (high_vma->vm_prev) \
  72                         high_vma->vm_prev->vm_next = NULL; \
  73                 else \
  74                         mm->mmap = NULL; \
  75                 rb_erase(&high_vma->vm_rb, &mm->mm_rb); \
  76                 mm->mmap_cache = NULL; \
  77                 mm->map_count--; \
  78                 remove_vma(high_vma); \
  79         } \
  80 } while (0)
  81
  82 static inline void arch_dup_mmap(struct mm_struct *oldmm,
  83                                  struct mm_struct *mm)
  84 {
  85 }
  86
  87 #endif