xref: /openbmc/linux/arch/um/include/asm/mmu_context.h (revision 482c86cc)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4  */
5 
6 #ifndef __UM_MMU_CONTEXT_H
7 #define __UM_MMU_CONTEXT_H
8 
9 #include <linux/sched.h>
10 #include <linux/mm_types.h>
11 
12 #include <asm/mmu.h>
13 
14 extern void uml_setup_stubs(struct mm_struct *mm);
15 /*
16  * Needed since we do not use the asm-generic/mm_hooks.h:
17  */
18 static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
19 {
20 	uml_setup_stubs(mm);
21 	return 0;
22 }
23 extern void arch_exit_mmap(struct mm_struct *mm);
24 static inline void arch_unmap(struct mm_struct *mm,
25 			unsigned long start, unsigned long end)
26 {
27 }
28 static inline void arch_bprm_mm_init(struct mm_struct *mm,
29 				     struct vm_area_struct *vma)
30 {
31 }
32 
33 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
34 		bool write, bool execute, bool foreign)
35 {
36 	/* by default, allow everything */
37 	return true;
38 }
39 
40 /*
41  * end asm-generic/mm_hooks.h functions
42  */
43 
44 #define deactivate_mm(tsk,mm)	do { } while (0)
45 
46 extern void force_flush_all(void);
47 
48 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
49 {
50 	/*
51 	 * This is called by fs/exec.c and sys_unshare()
52 	 * when the new ->mm is used for the first time.
53 	 */
54 	__switch_mm(&new->context.id);
55 	down_write_nested(&new->mmap_sem, 1);
56 	uml_setup_stubs(new);
57 	up_write(&new->mmap_sem);
58 }
59 
60 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
61 			     struct task_struct *tsk)
62 {
63 	unsigned cpu = smp_processor_id();
64 
65 	if(prev != next){
66 		cpumask_clear_cpu(cpu, mm_cpumask(prev));
67 		cpumask_set_cpu(cpu, mm_cpumask(next));
68 		if(next != &init_mm)
69 			__switch_mm(&next->context.id);
70 	}
71 }
72 
73 static inline void enter_lazy_tlb(struct mm_struct *mm,
74 				  struct task_struct *tsk)
75 {
76 }
77 
78 extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
79 
80 extern void destroy_context(struct mm_struct *mm);
81 
82 #endif
83