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
enter_lazy_tlb(struct mm_struct * mm,struct task_struct * tsk)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
switch_mm(struct mm_struct * prev,struct mm_struct * next,struct task_struct * tsk)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
arch_dup_mmap(struct mm_struct * oldmm,struct mm_struct * mm)82 static inline void arch_dup_mmap(struct mm_struct *oldmm,
83 struct mm_struct *mm)
84 {
85 }
86
87 #endif
88