LXR linux/arch/unicore32/include/asm/mmu

   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 */
  35static inline void
  36enter_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 */
  46static inline void
  47switch_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) \
  67do { \
  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
  82static inline void arch_dup_mmap(struct mm_struct *oldmm,
  83                                 struct mm_struct *mm)
  84{
  85}
  86
  87#endif
  88