Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
mmu_context.h
Go to the documentation of this file.
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