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 <asm/setup.h>
25 #include <asm/page.h>
26 #include <asm/pgalloc.h>
27 #include <asm/mem-layout.h>
28 
29 static inline void destroy_context(struct mm_struct *mm)
30 {
31 }
32 
33 /*
34  * VM port hides all TLB management, so "lazy TLB" isn't very
35  * meaningful.  Even for ports to architectures with visble TLBs,
36  * this is almost invariably a null function.
37  */
38 static inline void enter_lazy_tlb(struct mm_struct *mm,
39 	struct task_struct *tsk)
40 {
41 }
42 
43 /*
44  * Architecture-specific actions, if any, for memory map deactivation.
45  */
46 static inline void deactivate_mm(struct task_struct *tsk,
47 	struct mm_struct *mm)
48 {
49 }
50 
51 /**
52  * init_new_context - initialize context related info for new mm_struct instance
53  * @tsk: pointer to a task struct
54  * @mm: pointer to a new mm struct
55  */
56 static inline int init_new_context(struct task_struct *tsk,
57 					struct mm_struct *mm)
58 {
59 	/* mm->context is set up by pgd_alloc */
60 	return 0;
61 }
62 
63 /*
64  *  Switch active mm context
65  */
66 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
67 				struct task_struct *tsk)
68 {
69 	int l1;
70 
71 	/*
72 	 * For virtual machine, we have to update system map if it's been
73 	 * touched.
74 	 */
75 	if (next->context.generation < prev->context.generation) {
76 		for (l1 = MIN_KERNEL_SEG; l1 <= max_kernel_seg; l1++)
77 			next->pgd[l1] = init_mm.pgd[l1];
78 
79 		next->context.generation = prev->context.generation;
80 	}
81 
82 	__vmnewmap((void *)next->context.ptbase);
83 }
84 
85 /*
86  *  Activate new memory map for task
87  */
88 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
89 {
90 	unsigned long flags;
91 
92 	local_irq_save(flags);
93 	switch_mm(prev, next, current_thread_info()->task);
94 	local_irq_restore(flags);
95 }
96 
97 /*  Generic hooks for arch_dup_mmap and arch_exit_mmap  */
98 #include <asm-generic/mm_hooks.h>
99 
100 #endif
101