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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
33#include <asm/setup.h>
34#include <asm/page.h>
35#include <asm/pgalloc.h>
36
37extern void *current_l1_stack_save;
38extern int nr_l1stack_tasks;
39extern void *l1_stack_base;
40extern unsigned long l1_stack_len;
41
42extern int l1sram_free(const void*);
43extern void *l1sram_alloc_max(void*);
44
45static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
46{
47}
48
49/* Called when creating a new context during fork() or execve(). */
50static inline int
51init_new_context(struct task_struct *tsk, struct mm_struct *mm)
52{
53 return 0;
54}
55
56static inline void free_l1stack(void)
57{
58 nr_l1stack_tasks--;
59 if (nr_l1stack_tasks == 0)
60 l1sram_free(l1_stack_base);
61}
62static inline void destroy_context(struct mm_struct *mm)
63{
64 struct sram_list_struct *tmp;
65
66 if (current_l1_stack_save == mm->context.l1_stack_save)
67 current_l1_stack_save = 0;
68 if (mm->context.l1_stack_save)
69 free_l1stack();
70
71 while ((tmp = mm->context.sram_list)) {
72 mm->context.sram_list = tmp->next;
73 sram_free(tmp->addr);
74 kfree(tmp);
75 }
76}
77
78static inline unsigned long
79alloc_l1stack(unsigned long length, unsigned long *stack_base)
80{
81 if (nr_l1stack_tasks == 0) {
82 l1_stack_base = l1sram_alloc_max(&l1_stack_len);
83 if (!l1_stack_base)
84 return 0;
85 }
86
87 if (l1_stack_len < length) {
88 if (nr_l1stack_tasks == 0)
89 l1sram_free(l1_stack_base);
90 return 0;
91 }
92 *stack_base = (unsigned long)l1_stack_base;
93 nr_l1stack_tasks++;
94 return l1_stack_len;
95}
96
97static inline int
98activate_l1stack(struct mm_struct *mm, unsigned long sp_base)
99{
100 if (current_l1_stack_save)
101 memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
102 mm->context.l1_stack_save = current_l1_stack_save = (void*)sp_base;
103 memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
104 return 1;
105}
106
107#define deactivate_mm(tsk,mm) do { } while (0)
108
109static inline void activate_mm(struct mm_struct *prev_mm,
110 struct mm_struct *next_mm)
111{
112 if (!next_mm->context.l1_stack_save)
113 return;
114 if (next_mm->context.l1_stack_save == current_l1_stack_save)
115 return;
116 if (current_l1_stack_save) {
117 memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
118 }
119 current_l1_stack_save = next_mm->context.l1_stack_save;
120 memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
121}
122
123static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
124 struct task_struct *tsk)
125{
126 activate_mm(prev, next);
127}
128
129#endif