xref: /openbmc/linux/arch/um/include/asm/mmu_context.h (revision 8365a898)
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 #include <linux/mmap_lock.h>
12 
13 #include <asm/mmu.h>
14 
15 extern void uml_setup_stubs(struct mm_struct *mm);
16 /*
17  * Needed since we do not use the asm-generic/mm_hooks.h:
18  */
19 static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
20 {
21 	uml_setup_stubs(mm);
22 	return 0;
23 }
24 extern void arch_exit_mmap(struct mm_struct *mm);
25 static inline void arch_unmap(struct mm_struct *mm,
26 			unsigned long start, unsigned long end)
27 {
28 }
29 static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
30 		bool write, bool execute, bool foreign)
31 {
32 	/* by default, allow everything */
33 	return true;
34 }
35 
36 /*
37  * end asm-generic/mm_hooks.h functions
38  */
39 
40 #define deactivate_mm(tsk,mm)	do { } while (0)
41 
42 extern void force_flush_all(void);
43 
44 static inline void activate_mm(struct mm_struct *old, struct mm_struct *new)
45 {
46 	/*
47 	 * This is called by fs/exec.c and sys_unshare()
48 	 * when the new ->mm is used for the first time.
49 	 */
50 	__switch_mm(&new->context.id);
51 	mmap_write_lock_nested(new, SINGLE_DEPTH_NESTING);
52 	uml_setup_stubs(new);
53 	mmap_write_unlock(new);
54 }
55 
56 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
57 			     struct task_struct *tsk)
58 {
59 	unsigned cpu = smp_processor_id();
60 
61 	if(prev != next){
62 		cpumask_clear_cpu(cpu, mm_cpumask(prev));
63 		cpumask_set_cpu(cpu, mm_cpumask(next));
64 		if(next != &init_mm)
65 			__switch_mm(&next->context.id);
66 	}
67 }
68 
69 static inline void enter_lazy_tlb(struct mm_struct *mm,
70 				  struct task_struct *tsk)
71 {
72 }
73 
74 extern int init_new_context(struct task_struct *task, struct mm_struct *mm);
75 
76 extern void destroy_context(struct mm_struct *mm);
77 
78 #endif
79