1 /*
2  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2008-2009 PetaLogix
4  * Copyright (C) 2006 Atmark Techno, Inc.
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License. See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 
11 #ifndef _ASM_MICROBLAZE_PROCESSOR_H
12 #define _ASM_MICROBLAZE_PROCESSOR_H
13 
14 #include <asm/ptrace.h>
15 #include <asm/setup.h>
16 #include <asm/registers.h>
17 #include <asm/segment.h>
18 #include <asm/entry.h>
19 #include <asm/current.h>
20 
21 # ifndef __ASSEMBLY__
22 /* from kernel/cpu/mb.c */
23 extern const struct seq_operations cpuinfo_op;
24 
25 # define cpu_relax()		barrier()
26 # define cpu_sleep()		do {} while (0)
27 # define prepare_to_copy(tsk)	do {} while (0)
28 
29 #define task_pt_regs(tsk) \
30 		(((struct pt_regs *)(THREAD_SIZE + task_stack_page(tsk))) - 1)
31 
32 /* Do necessary setup to start up a newly executed thread. */
33 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp);
34 
35 # endif /* __ASSEMBLY__ */
36 
37 # ifndef CONFIG_MMU
38 /*
39  * User space process size: memory size
40  *
41  * TASK_SIZE on MMU cpu is usually 1GB. However, on no-MMU arch, both
42  * user processes and the kernel is on the same memory region. They
43  * both share the memory space and that is limited by the amount of
44  * physical memory. thus, we set TASK_SIZE == amount of total memory.
45  */
46 # define TASK_SIZE	(0x81000000 - 0x80000000)
47 
48 /*
49  * Default implementation of macro that returns current
50  * instruction pointer ("program counter").
51  */
52 # define current_text_addr() ({ __label__ _l; _l: &&_l; })
53 
54 /*
55  * This decides where the kernel will search for a free chunk of vm
56  * space during mmap's. We won't be using it
57  */
58 # define TASK_UNMAPPED_BASE	0
59 
60 /* definition in include/linux/sched.h */
61 struct task_struct;
62 
63 /* thread_struct is gone. use thread_info instead. */
64 struct thread_struct { };
65 # define INIT_THREAD	{ }
66 
67 /* Free all resources held by a thread. */
68 static inline void release_thread(struct task_struct *dead_task)
69 {
70 }
71 
72 /* Free all resources held by a thread. */
73 static inline void exit_thread(void)
74 {
75 }
76 
77 extern unsigned long thread_saved_pc(struct task_struct *t);
78 
79 extern unsigned long get_wchan(struct task_struct *p);
80 
81 /*
82  * create a kernel thread without removing it from tasklists
83  */
84 extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
85 
86 # define KSTK_EIP(tsk)	(0)
87 # define KSTK_ESP(tsk)	(0)
88 
89 # else /* CONFIG_MMU */
90 
91 /*
92  * This is used to define STACK_TOP, and with MMU it must be below
93  * kernel base to select the correct PGD when handling MMU exceptions.
94  */
95 # define TASK_SIZE	(CONFIG_KERNEL_START)
96 
97 /*
98  * This decides where the kernel will search for a free chunk of vm
99  * space during mmap's.
100  */
101 # define TASK_UNMAPPED_BASE	(TASK_SIZE / 8 * 3)
102 
103 # define THREAD_KSP	0
104 
105 #  ifndef __ASSEMBLY__
106 
107 /*
108  * Default implementation of macro that returns current
109  * instruction pointer ("program counter").
110  */
111 #  define current_text_addr()	({ __label__ _l; _l: &&_l; })
112 
113 /* If you change this, you must change the associated assembly-languages
114  * constants defined below, THREAD_*.
115  */
116 struct thread_struct {
117 	/* kernel stack pointer (must be first field in structure) */
118 	unsigned long	ksp;
119 	unsigned long	ksp_limit;	/* if ksp <= ksp_limit stack overflow */
120 	void		*pgdir;		/* root of page-table tree */
121 	struct pt_regs	*regs;		/* Pointer to saved register state */
122 };
123 
124 #  define INIT_THREAD { \
125 	.ksp   = sizeof init_stack + (unsigned long)init_stack, \
126 	.pgdir = swapper_pg_dir, \
127 }
128 
129 /* Do necessary setup to start up a newly executed thread.  */
130 void start_thread(struct pt_regs *regs,
131 		unsigned long pc, unsigned long usp);
132 
133 /* Free all resources held by a thread. */
134 extern inline void release_thread(struct task_struct *dead_task)
135 {
136 }
137 
138 extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
139 
140 /* Free current thread data structures etc.  */
141 static inline void exit_thread(void)
142 {
143 }
144 
145 /* Return saved (kernel) PC of a blocked thread.  */
146 #  define thread_saved_pc(tsk)	\
147 	((tsk)->thread.regs ? (tsk)->thread.regs->r15 : 0)
148 
149 unsigned long get_wchan(struct task_struct *p);
150 
151 /* The size allocated for kernel stacks. This _must_ be a power of two! */
152 # define KERNEL_STACK_SIZE	0x2000
153 
154 /* Return some info about the user process TASK.  */
155 #  define task_tos(task)	((unsigned long)(task) + KERNEL_STACK_SIZE)
156 #  define task_regs(task) ((struct pt_regs *)task_tos(task) - 1)
157 
158 #  define task_pt_regs_plus_args(tsk) \
159 	(((void *)task_pt_regs(tsk)) - STATE_SAVE_ARG_SPACE)
160 
161 #  define task_sp(task)	(task_regs(task)->r1)
162 #  define task_pc(task)	(task_regs(task)->pc)
163 /* Grotty old names for some.  */
164 #  define KSTK_EIP(task)	(task_pc(task))
165 #  define KSTK_ESP(task)	(task_sp(task))
166 
167 /* FIXME */
168 #  define deactivate_mm(tsk, mm)	do { } while (0)
169 
170 #  define STACK_TOP	TASK_SIZE
171 #  define STACK_TOP_MAX	STACK_TOP
172 
173 #  endif /* __ASSEMBLY__ */
174 # endif /* CONFIG_MMU */
175 #endif /* _ASM_MICROBLAZE_PROCESSOR_H */
176