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Bryan Wu1394f032007-05-06 14:50:22 -07001/*
2 * File: include/asm-blackfin/mmu_context.h
3 * Based on:
4 * Author:
5 *
6 * Created:
7 * Description:
8 *
9 * Modified:
10 * Copyright 2004-2006 Analog Devices Inc.
11 *
12 * Bugs: Enter bugs at http://blackfin.uclinux.org/
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, see the file COPYING, or write
26 * to the Free Software Foundation, Inc.,
27 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
28 */
29
30#ifndef __BLACKFIN_MMU_CONTEXT_H__
31#define __BLACKFIN_MMU_CONTEXT_H__
32
Bernd Schmidtb97b8a92008-01-27 18:39:16 +080033#include <linux/gfp.h>
34#include <linux/sched.h>
Bryan Wu1394f032007-05-06 14:50:22 -070035#include <asm/setup.h>
36#include <asm/page.h>
37#include <asm/pgalloc.h>
Bernd Schmidtb97b8a92008-01-27 18:39:16 +080038#include <asm/cplbinit.h>
Bryan Wu1394f032007-05-06 14:50:22 -070039
40extern void *current_l1_stack_save;
41extern int nr_l1stack_tasks;
42extern void *l1_stack_base;
43extern unsigned long l1_stack_len;
44
45extern int l1sram_free(const void*);
46extern void *l1sram_alloc_max(void*);
47
48static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
49{
50}
51
52/* Called when creating a new context during fork() or execve(). */
53static inline int
54init_new_context(struct task_struct *tsk, struct mm_struct *mm)
55{
Bernd Schmidtb97b8a92008-01-27 18:39:16 +080056#ifdef CONFIG_MPU
57 unsigned long p = __get_free_pages(GFP_KERNEL, page_mask_order);
58 mm->context.page_rwx_mask = (unsigned long *)p;
59 memset(mm->context.page_rwx_mask, 0,
60 page_mask_nelts * 3 * sizeof(long));
61#endif
Bryan Wu1394f032007-05-06 14:50:22 -070062 return 0;
63}
64
65static inline void free_l1stack(void)
66{
67 nr_l1stack_tasks--;
68 if (nr_l1stack_tasks == 0)
69 l1sram_free(l1_stack_base);
70}
71static inline void destroy_context(struct mm_struct *mm)
72{
73 struct sram_list_struct *tmp;
74
75 if (current_l1_stack_save == mm->context.l1_stack_save)
76 current_l1_stack_save = 0;
77 if (mm->context.l1_stack_save)
78 free_l1stack();
79
80 while ((tmp = mm->context.sram_list)) {
81 mm->context.sram_list = tmp->next;
82 sram_free(tmp->addr);
83 kfree(tmp);
84 }
Bernd Schmidtb97b8a92008-01-27 18:39:16 +080085#ifdef CONFIG_MPU
86 if (current_rwx_mask == mm->context.page_rwx_mask)
87 current_rwx_mask = NULL;
88 free_pages((unsigned long)mm->context.page_rwx_mask, page_mask_order);
89#endif
Bryan Wu1394f032007-05-06 14:50:22 -070090}
91
92static inline unsigned long
93alloc_l1stack(unsigned long length, unsigned long *stack_base)
94{
95 if (nr_l1stack_tasks == 0) {
96 l1_stack_base = l1sram_alloc_max(&l1_stack_len);
97 if (!l1_stack_base)
98 return 0;
99 }
100
101 if (l1_stack_len < length) {
102 if (nr_l1stack_tasks == 0)
103 l1sram_free(l1_stack_base);
104 return 0;
105 }
106 *stack_base = (unsigned long)l1_stack_base;
107 nr_l1stack_tasks++;
108 return l1_stack_len;
109}
110
111static inline int
112activate_l1stack(struct mm_struct *mm, unsigned long sp_base)
113{
114 if (current_l1_stack_save)
115 memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
116 mm->context.l1_stack_save = current_l1_stack_save = (void*)sp_base;
117 memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
118 return 1;
119}
120
121#define deactivate_mm(tsk,mm) do { } while (0)
122
Bernd Schmidtb97b8a92008-01-27 18:39:16 +0800123#define activate_mm(prev, next) switch_mm(prev, next, NULL)
124
125static inline void switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm,
126 struct task_struct *tsk)
Bryan Wu1394f032007-05-06 14:50:22 -0700127{
Bernd Schmidtb97b8a92008-01-27 18:39:16 +0800128 if (prev_mm == next_mm)
129 return;
130#ifdef CONFIG_MPU
131 if (prev_mm->context.page_rwx_mask == current_rwx_mask) {
132 flush_switched_cplbs();
133 set_mask_dcplbs(next_mm->context.page_rwx_mask);
134 }
135#endif
136
137 /* L1 stack switching. */
Bryan Wu1394f032007-05-06 14:50:22 -0700138 if (!next_mm->context.l1_stack_save)
139 return;
140 if (next_mm->context.l1_stack_save == current_l1_stack_save)
141 return;
142 if (current_l1_stack_save) {
143 memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
144 }
145 current_l1_stack_save = next_mm->context.l1_stack_save;
146 memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
147}
148
Bernd Schmidtb97b8a92008-01-27 18:39:16 +0800149#ifdef CONFIG_MPU
150static inline void protect_page(struct mm_struct *mm, unsigned long addr,
151 unsigned long flags)
Bryan Wu1394f032007-05-06 14:50:22 -0700152{
Bernd Schmidtb97b8a92008-01-27 18:39:16 +0800153 unsigned long *mask = mm->context.page_rwx_mask;
154 unsigned long page = addr >> 12;
155 unsigned long idx = page >> 5;
156 unsigned long bit = 1 << (page & 31);
157
158 if (flags & VM_MAYREAD)
159 mask[idx] |= bit;
160 else
161 mask[idx] &= ~bit;
162 mask += page_mask_nelts;
163 if (flags & VM_MAYWRITE)
164 mask[idx] |= bit;
165 else
166 mask[idx] &= ~bit;
167 mask += page_mask_nelts;
168 if (flags & VM_MAYEXEC)
169 mask[idx] |= bit;
170 else
171 mask[idx] &= ~bit;
Bryan Wu1394f032007-05-06 14:50:22 -0700172}
173
Bernd Schmidtb97b8a92008-01-27 18:39:16 +0800174static inline void update_protections(struct mm_struct *mm)
175{
176 flush_switched_cplbs();
177 set_mask_dcplbs(mm->context.page_rwx_mask);
178}
179#endif
180
Bryan Wu1394f032007-05-06 14:50:22 -0700181#endif