xref: /openbmc/linux/arch/um/include/asm/mmu_context.h (revision bc5aa3a0)
1 /*
2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5 
6 #ifndef __UM_MMU_CONTEXT_H
7 #define __UM_MMU_CONTEXT_H
8 
9 #include <linux/sched.h>
10 #include <asm/mmu.h>
11 
12 extern void uml_setup_stubs(struct mm_struct *mm);
13 /*
14  * Needed since we do not use the asm-generic/mm_hooks.h:
15  */
16 static inline void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
17 {
18 	uml_setup_stubs(mm);
19 }
20 extern void arch_exit_mmap(struct mm_struct *mm);
21 static inline void arch_unmap(struct mm_struct *mm,
22 			struct vm_area_struct *vma,
23 			unsigned long start, unsigned long end)
24 {
25 }
26 static inline void arch_bprm_mm_init(struct mm_struct *mm,
27 				     struct vm_area_struct *vma)
28 {
29 }
30 
31 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
32 		bool write, bool execute, bool foreign)
33 {
34 	/* by default, allow everything */
35 	return true;
36 }
37 
38 static inline bool arch_pte_access_permitted(pte_t pte, bool write)
39 {
40 	/* by default, allow everything */
41 	return true;
42 }
43 
44 /*
45  * end asm-generic/mm_hooks.h functions
46  */
47 
48 #define deactivate_mm(tsk,mm)	do { } while (0)
49 
50 extern void force_flush_all(void);
51 
52 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
53 {
54 	/*
55 	 * This is called by fs/exec.c and sys_unshare()
56 	 * when the new ->mm is used for the first time.
57 	 */
58 	__switch_mm(&new->context.id);
59 	down_write(&new->mmap_sem);
60 	uml_setup_stubs(new);
61 	up_write(&new->mmap_sem);
62 }
63 
64 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
65 			     struct task_struct *tsk)
66 {
67 	unsigned cpu = smp_processor_id();
68 
69 	if(prev != next){
70 		cpumask_clear_cpu(cpu, mm_cpumask(prev));
71 		cpumask_set_cpu(cpu, mm_cpumask(next));
72 		if(next != &init_mm)
73 			__switch_mm(&next->context.id);
74 	}
75 }
76 
77 static inline void enter_lazy_tlb(struct mm_struct *mm,
78 				  struct task_struct *tsk)
79 {
80 }
81 
82 extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
83 
84 extern void destroy_context(struct mm_struct *mm);
85 
86 #endif
87