1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * MM context support for the Hexagon architecture
4  *
5  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
6  */
7 
8 #ifndef _ASM_MMU_CONTEXT_H
9 #define _ASM_MMU_CONTEXT_H
10 
11 #include <linux/mm_types.h>
12 
13 #include <asm/setup.h>
14 #include <asm/page.h>
15 #include <asm/pgalloc.h>
16 #include <asm/mem-layout.h>
17 
18 static inline void destroy_context(struct mm_struct *mm)
19 {
20 }
21 
22 /*
23  * VM port hides all TLB management, so "lazy TLB" isn't very
24  * meaningful.  Even for ports to architectures with visble TLBs,
25  * this is almost invariably a null function.
26  */
27 static inline void enter_lazy_tlb(struct mm_struct *mm,
28 	struct task_struct *tsk)
29 {
30 }
31 
32 /*
33  * Architecture-specific actions, if any, for memory map deactivation.
34  */
35 static inline void deactivate_mm(struct task_struct *tsk,
36 	struct mm_struct *mm)
37 {
38 }
39 
40 /**
41  * init_new_context - initialize context related info for new mm_struct instance
42  * @tsk: pointer to a task struct
43  * @mm: pointer to a new mm struct
44  */
45 static inline int init_new_context(struct task_struct *tsk,
46 					struct mm_struct *mm)
47 {
48 	/* mm->context is set up by pgd_alloc */
49 	return 0;
50 }
51 
52 /*
53  *  Switch active mm context
54  */
55 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
56 				struct task_struct *tsk)
57 {
58 	int l1;
59 
60 	/*
61 	 * For virtual machine, we have to update system map if it's been
62 	 * touched.
63 	 */
64 	if (next->context.generation < prev->context.generation) {
65 		for (l1 = MIN_KERNEL_SEG; l1 <= max_kernel_seg; l1++)
66 			next->pgd[l1] = init_mm.pgd[l1];
67 
68 		next->context.generation = prev->context.generation;
69 	}
70 
71 	__vmnewmap((void *)next->context.ptbase);
72 }
73 
74 /*
75  *  Activate new memory map for task
76  */
77 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
78 {
79 	unsigned long flags;
80 
81 	local_irq_save(flags);
82 	switch_mm(prev, next, current_thread_info()->task);
83 	local_irq_restore(flags);
84 }
85 
86 /*  Generic hooks for arch_dup_mmap and arch_exit_mmap  */
87 #include <asm-generic/mm_hooks.h>
88 
89 #endif
90