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 extern unsigned long get_wchan(struct task_struct *p);
73 
74 # define KSTK_EIP(tsk)	(0)
75 # define KSTK_ESP(tsk)	(0)
76 
77 # else /* CONFIG_MMU */
78 
79 /*
80  * This is used to define STACK_TOP, and with MMU it must be below
81  * kernel base to select the correct PGD when handling MMU exceptions.
82  */
83 # define TASK_SIZE	(CONFIG_KERNEL_START)
84 
85 /*
86  * This decides where the kernel will search for a free chunk of vm
87  * space during mmap's.
88  */
89 # define TASK_UNMAPPED_BASE	(TASK_SIZE / 8 * 3)
90 
91 # define THREAD_KSP	0
92 
93 #  ifndef __ASSEMBLY__
94 
95 /*
96  * Default implementation of macro that returns current
97  * instruction pointer ("program counter").
98  */
99 #  define current_text_addr()	({ __label__ _l; _l: &&_l; })
100 
101 /* If you change this, you must change the associated assembly-languages
102  * constants defined below, THREAD_*.
103  */
104 struct thread_struct {
105 	/* kernel stack pointer (must be first field in structure) */
106 	unsigned long	ksp;
107 	unsigned long	ksp_limit;	/* if ksp <= ksp_limit stack overflow */
108 	void		*pgdir;		/* root of page-table tree */
109 	struct pt_regs	*regs;		/* Pointer to saved register state */
110 };
111 
112 #  define INIT_THREAD { \
113 	.ksp   = sizeof init_stack + (unsigned long)init_stack, \
114 	.pgdir = swapper_pg_dir, \
115 }
116 
117 /* Free all resources held by a thread. */
118 static inline void release_thread(struct task_struct *dead_task)
119 {
120 }
121 
122 unsigned long get_wchan(struct task_struct *p);
123 
124 /* The size allocated for kernel stacks. This _must_ be a power of two! */
125 # define KERNEL_STACK_SIZE	0x2000
126 
127 /* Return some info about the user process TASK.  */
128 #  define task_tos(task)	((unsigned long)(task) + KERNEL_STACK_SIZE)
129 #  define task_regs(task) ((struct pt_regs *)task_tos(task) - 1)
130 
131 #  define task_pt_regs_plus_args(tsk) \
132 	((void *)task_pt_regs(tsk))
133 
134 #  define task_sp(task)	(task_regs(task)->r1)
135 #  define task_pc(task)	(task_regs(task)->pc)
136 /* Grotty old names for some.  */
137 #  define KSTK_EIP(task)	(task_pc(task))
138 #  define KSTK_ESP(task)	(task_sp(task))
139 
140 /* FIXME */
141 #  define deactivate_mm(tsk, mm)	do { } while (0)
142 
143 #  define STACK_TOP	TASK_SIZE
144 #  define STACK_TOP_MAX	STACK_TOP
145 
146 #ifdef CONFIG_DEBUG_FS
147 extern struct dentry *of_debugfs_root;
148 #endif
149 
150 #  endif /* __ASSEMBLY__ */
151 # endif /* CONFIG_MMU */
152 #endif /* _ASM_MICROBLAZE_PROCESSOR_H */
153