xref: /openbmc/linux/arch/um/include/asm/mmu_context.h (revision dc6a81c3)
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 bool arch_vma_access_permitted(struct vm_area_struct *vma,
29 		bool write, bool execute, bool foreign)
30 {
31 	/* by default, allow everything */
32 	return true;
33 }
34 
35 /*
36  * end asm-generic/mm_hooks.h functions
37  */
38 
39 #define deactivate_mm(tsk,mm)	do { } while (0)
40 
41 extern void force_flush_all(void);
42 
43 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
44 {
45 	/*
46 	 * This is called by fs/exec.c and sys_unshare()
47 	 * when the new ->mm is used for the first time.
48 	 */
49 	__switch_mm(&new->context.id);
50 	down_write_nested(&new->mmap_sem, 1);
51 	uml_setup_stubs(new);
52 	up_write(&new->mmap_sem);
53 }
54 
55 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
56 			     struct task_struct *tsk)
57 {
58 	unsigned cpu = smp_processor_id();
59 
60 	if(prev != next){
61 		cpumask_clear_cpu(cpu, mm_cpumask(prev));
62 		cpumask_set_cpu(cpu, mm_cpumask(next));
63 		if(next != &init_mm)
64 			__switch_mm(&next->context.id);
65 	}
66 }
67 
68 static inline void enter_lazy_tlb(struct mm_struct *mm,
69 				  struct task_struct *tsk)
70 {
71 }
72 
73 extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
74 
75 extern void destroy_context(struct mm_struct *mm);
76 
77 #endif
78