xref: /linux/arch/microblaze/include/asm/processor.h (revision 988b0c541ed8b1c633c4d4df7169010635942e18)
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/entry.h>
18 #include <asm/current.h>
19 
20 # ifndef __ASSEMBLY__
21 /* from kernel/cpu/mb.c */
22 extern const struct seq_operations cpuinfo_op;
23 
24 # define cpu_relax()		barrier()
25 
26 #define task_pt_regs(tsk) \
27 		(((struct pt_regs *)(THREAD_SIZE + task_stack_page(tsk))) - 1)
28 
29 /* Do necessary setup to start up a newly executed thread. */
30 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp);
31 
32 extern void ret_from_fork(void);
33 extern void ret_from_kernel_thread(void);
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 # define KSTK_EIP(tsk)	(0)
82 # define KSTK_ESP(tsk)	(0)
83 
84 # else /* CONFIG_MMU */
85 
86 /*
87  * This is used to define STACK_TOP, and with MMU it must be below
88  * kernel base to select the correct PGD when handling MMU exceptions.
89  */
90 # define TASK_SIZE	(CONFIG_KERNEL_START)
91 
92 /*
93  * This decides where the kernel will search for a free chunk of vm
94  * space during mmap's.
95  */
96 # define TASK_UNMAPPED_BASE	(TASK_SIZE / 8 * 3)
97 
98 # define THREAD_KSP	0
99 
100 #  ifndef __ASSEMBLY__
101 
102 /*
103  * Default implementation of macro that returns current
104  * instruction pointer ("program counter").
105  */
106 #  define current_text_addr()	({ __label__ _l; _l: &&_l; })
107 
108 /* If you change this, you must change the associated assembly-languages
109  * constants defined below, THREAD_*.
110  */
111 struct thread_struct {
112 	/* kernel stack pointer (must be first field in structure) */
113 	unsigned long	ksp;
114 	unsigned long	ksp_limit;	/* if ksp <= ksp_limit stack overflow */
115 	void		*pgdir;		/* root of page-table tree */
116 	struct pt_regs	*regs;		/* Pointer to saved register state */
117 };
118 
119 #  define INIT_THREAD { \
120 	.ksp   = sizeof init_stack + (unsigned long)init_stack, \
121 	.pgdir = swapper_pg_dir, \
122 }
123 
124 /* Free all resources held by a thread. */
125 static inline void release_thread(struct task_struct *dead_task)
126 {
127 }
128 
129 /* Free current thread data structures etc.  */
130 static inline void exit_thread(void)
131 {
132 }
133 
134 /* Return saved (kernel) PC of a blocked thread.  */
135 #  define thread_saved_pc(tsk)	\
136 	((tsk)->thread.regs ? (tsk)->thread.regs->r15 : 0)
137 
138 unsigned long get_wchan(struct task_struct *p);
139 
140 /* The size allocated for kernel stacks. This _must_ be a power of two! */
141 # define KERNEL_STACK_SIZE	0x2000
142 
143 /* Return some info about the user process TASK.  */
144 #  define task_tos(task)	((unsigned long)(task) + KERNEL_STACK_SIZE)
145 #  define task_regs(task) ((struct pt_regs *)task_tos(task) - 1)
146 
147 #  define task_pt_regs_plus_args(tsk) \
148 	((void *)task_pt_regs(tsk))
149 
150 #  define task_sp(task)	(task_regs(task)->r1)
151 #  define task_pc(task)	(task_regs(task)->pc)
152 /* Grotty old names for some.  */
153 #  define KSTK_EIP(task)	(task_pc(task))
154 #  define KSTK_ESP(task)	(task_sp(task))
155 
156 /* FIXME */
157 #  define deactivate_mm(tsk, mm)	do { } while (0)
158 
159 #  define STACK_TOP	TASK_SIZE
160 #  define STACK_TOP_MAX	STACK_TOP
161 
162 #ifdef CONFIG_DEBUG_FS
163 extern struct dentry *of_debugfs_root;
164 #endif
165 
166 #  endif /* __ASSEMBLY__ */
167 # endif /* CONFIG_MMU */
168 #endif /* _ASM_MICROBLAZE_PROCESSOR_H */
169