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 # define cpu_relax_lowlatency()	cpu_relax()
26 
27 #define task_pt_regs(tsk) \
28 		(((struct pt_regs *)(THREAD_SIZE + task_stack_page(tsk))) - 1)
29 
30 /* Do necessary setup to start up a newly executed thread. */
31 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp);
32 
33 extern void ret_from_fork(void);
34 extern void ret_from_kernel_thread(void);
35 
36 # endif /* __ASSEMBLY__ */
37 
38 # ifndef CONFIG_MMU
39 /*
40  * User space process size: memory size
41  *
42  * TASK_SIZE on MMU cpu is usually 1GB. However, on no-MMU arch, both
43  * user processes and the kernel is on the same memory region. They
44  * both share the memory space and that is limited by the amount of
45  * physical memory. thus, we set TASK_SIZE == amount of total memory.
46  */
47 # define TASK_SIZE	(0x81000000 - 0x80000000)
48 
49 /*
50  * Default implementation of macro that returns current
51  * instruction pointer ("program counter").
52  */
53 # define current_text_addr() ({ __label__ _l; _l: &&_l; })
54 
55 /*
56  * This decides where the kernel will search for a free chunk of vm
57  * space during mmap's. We won't be using it
58  */
59 # define TASK_UNMAPPED_BASE	0
60 
61 /* definition in include/linux/sched.h */
62 struct task_struct;
63 
64 /* thread_struct is gone. use thread_info instead. */
65 struct thread_struct { };
66 # define INIT_THREAD	{ }
67 
68 /* Free all resources held by a thread. */
69 static inline void release_thread(struct task_struct *dead_task)
70 {
71 }
72 
73 extern unsigned long thread_saved_pc(struct task_struct *t);
74 
75 extern unsigned long get_wchan(struct task_struct *p);
76 
77 # define KSTK_EIP(tsk)	(0)
78 # define KSTK_ESP(tsk)	(0)
79 
80 # else /* CONFIG_MMU */
81 
82 /*
83  * This is used to define STACK_TOP, and with MMU it must be below
84  * kernel base to select the correct PGD when handling MMU exceptions.
85  */
86 # define TASK_SIZE	(CONFIG_KERNEL_START)
87 
88 /*
89  * This decides where the kernel will search for a free chunk of vm
90  * space during mmap's.
91  */
92 # define TASK_UNMAPPED_BASE	(TASK_SIZE / 8 * 3)
93 
94 # define THREAD_KSP	0
95 
96 #  ifndef __ASSEMBLY__
97 
98 /*
99  * Default implementation of macro that returns current
100  * instruction pointer ("program counter").
101  */
102 #  define current_text_addr()	({ __label__ _l; _l: &&_l; })
103 
104 /* If you change this, you must change the associated assembly-languages
105  * constants defined below, THREAD_*.
106  */
107 struct thread_struct {
108 	/* kernel stack pointer (must be first field in structure) */
109 	unsigned long	ksp;
110 	unsigned long	ksp_limit;	/* if ksp <= ksp_limit stack overflow */
111 	void		*pgdir;		/* root of page-table tree */
112 	struct pt_regs	*regs;		/* Pointer to saved register state */
113 };
114 
115 #  define INIT_THREAD { \
116 	.ksp   = sizeof init_stack + (unsigned long)init_stack, \
117 	.pgdir = swapper_pg_dir, \
118 }
119 
120 /* Free all resources held by a thread. */
121 static inline void release_thread(struct task_struct *dead_task)
122 {
123 }
124 
125 /* Return saved (kernel) PC of a blocked thread.  */
126 #  define thread_saved_pc(tsk)	\
127 	((tsk)->thread.regs ? (tsk)->thread.regs->r15 : 0)
128 
129 unsigned long get_wchan(struct task_struct *p);
130 
131 /* The size allocated for kernel stacks. This _must_ be a power of two! */
132 # define KERNEL_STACK_SIZE	0x2000
133 
134 /* Return some info about the user process TASK.  */
135 #  define task_tos(task)	((unsigned long)(task) + KERNEL_STACK_SIZE)
136 #  define task_regs(task) ((struct pt_regs *)task_tos(task) - 1)
137 
138 #  define task_pt_regs_plus_args(tsk) \
139 	((void *)task_pt_regs(tsk))
140 
141 #  define task_sp(task)	(task_regs(task)->r1)
142 #  define task_pc(task)	(task_regs(task)->pc)
143 /* Grotty old names for some.  */
144 #  define KSTK_EIP(task)	(task_pc(task))
145 #  define KSTK_ESP(task)	(task_sp(task))
146 
147 /* FIXME */
148 #  define deactivate_mm(tsk, mm)	do { } while (0)
149 
150 #  define STACK_TOP	TASK_SIZE
151 #  define STACK_TOP_MAX	STACK_TOP
152 
153 #ifdef CONFIG_DEBUG_FS
154 extern struct dentry *of_debugfs_root;
155 #endif
156 
157 #  endif /* __ASSEMBLY__ */
158 # endif /* CONFIG_MMU */
159 #endif /* _ASM_MICROBLAZE_PROCESSOR_H */
160