1 /*
2  * MM context support for the Hexagon architecture
3  *
4  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 and
8  * only version 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA.
19  */
20 
21 #ifndef _ASM_MMU_CONTEXT_H
22 #define _ASM_MMU_CONTEXT_H
23 
24 #include <linux/mm_types.h>
25 
26 #include <asm/setup.h>
27 #include <asm/page.h>
28 #include <asm/pgalloc.h>
29 #include <asm/mem-layout.h>
30 
31 static inline void destroy_context(struct mm_struct *mm)
32 {
33 }
34 
35 /*
36  * VM port hides all TLB management, so "lazy TLB" isn't very
37  * meaningful.  Even for ports to architectures with visble TLBs,
38  * this is almost invariably a null function.
39  */
40 static inline void enter_lazy_tlb(struct mm_struct *mm,
41 	struct task_struct *tsk)
42 {
43 }
44 
45 /*
46  * Architecture-specific actions, if any, for memory map deactivation.
47  */
48 static inline void deactivate_mm(struct task_struct *tsk,
49 	struct mm_struct *mm)
50 {
51 }
52 
53 /**
54  * init_new_context - initialize context related info for new mm_struct instance
55  * @tsk: pointer to a task struct
56  * @mm: pointer to a new mm struct
57  */
58 static inline int init_new_context(struct task_struct *tsk,
59 					struct mm_struct *mm)
60 {
61 	/* mm->context is set up by pgd_alloc */
62 	return 0;
63 }
64 
65 /*
66  *  Switch active mm context
67  */
68 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
69 				struct task_struct *tsk)
70 {
71 	int l1;
72 
73 	/*
74 	 * For virtual machine, we have to update system map if it's been
75 	 * touched.
76 	 */
77 	if (next->context.generation < prev->context.generation) {
78 		for (l1 = MIN_KERNEL_SEG; l1 <= max_kernel_seg; l1++)
79 			next->pgd[l1] = init_mm.pgd[l1];
80 
81 		next->context.generation = prev->context.generation;
82 	}
83 
84 	__vmnewmap((void *)next->context.ptbase);
85 }
86 
87 /*
88  *  Activate new memory map for task
89  */
90 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
91 {
92 	unsigned long flags;
93 
94 	local_irq_save(flags);
95 	switch_mm(prev, next, current_thread_info()->task);
96 	local_irq_restore(flags);
97 }
98 
99 /*  Generic hooks for arch_dup_mmap and arch_exit_mmap  */
100 #include <asm-generic/mm_hooks.h>
101 
102 #endif
103