1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
4  * Copyright (C) 2008-2009 PetaLogix
5  * Copyright (C) 2006 Atmark Techno, Inc.
6  */
7 
8 #ifndef _ASM_MICROBLAZE_PROCESSOR_H
9 #define _ASM_MICROBLAZE_PROCESSOR_H
10 
11 #include <asm/ptrace.h>
12 #include <asm/setup.h>
13 #include <asm/registers.h>
14 #include <asm/entry.h>
15 #include <asm/current.h>
16 
17 # ifndef __ASSEMBLY__
18 /* from kernel/cpu/mb.c */
19 extern const struct seq_operations cpuinfo_op;
20 
21 # define cpu_relax()		barrier()
22 
23 #define task_pt_regs(tsk) \
24 		(((struct pt_regs *)(THREAD_SIZE + task_stack_page(tsk))) - 1)
25 
26 /* Do necessary setup to start up a newly executed thread. */
27 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp);
28 
29 extern void ret_from_fork(void);
30 extern void ret_from_kernel_thread(void);
31 
32 # endif /* __ASSEMBLY__ */
33 
34 # ifndef CONFIG_MMU
35 /*
36  * User space process size: memory size
37  *
38  * TASK_SIZE on MMU cpu is usually 1GB. However, on no-MMU arch, both
39  * user processes and the kernel is on the same memory region. They
40  * both share the memory space and that is limited by the amount of
41  * physical memory. thus, we set TASK_SIZE == amount of total memory.
42  */
43 # define TASK_SIZE	(0x81000000 - 0x80000000)
44 
45 /*
46  * This decides where the kernel will search for a free chunk of vm
47  * space during mmap's. We won't be using it
48  */
49 # define TASK_UNMAPPED_BASE	0
50 
51 /* definition in include/linux/sched.h */
52 struct task_struct;
53 
54 /* thread_struct is gone. use thread_info instead. */
55 struct thread_struct { };
56 # define INIT_THREAD	{ }
57 
58 /* Free all resources held by a thread. */
59 static inline void release_thread(struct task_struct *dead_task)
60 {
61 }
62 
63 extern unsigned long get_wchan(struct task_struct *p);
64 
65 # define KSTK_EIP(tsk)	(0)
66 # define KSTK_ESP(tsk)	(0)
67 
68 # else /* CONFIG_MMU */
69 
70 /*
71  * This is used to define STACK_TOP, and with MMU it must be below
72  * kernel base to select the correct PGD when handling MMU exceptions.
73  */
74 # define TASK_SIZE	(CONFIG_KERNEL_START)
75 
76 /*
77  * This decides where the kernel will search for a free chunk of vm
78  * space during mmap's.
79  */
80 # define TASK_UNMAPPED_BASE	(TASK_SIZE / 8 * 3)
81 
82 # define THREAD_KSP	0
83 
84 #  ifndef __ASSEMBLY__
85 
86 /* If you change this, you must change the associated assembly-languages
87  * constants defined below, THREAD_*.
88  */
89 struct thread_struct {
90 	/* kernel stack pointer (must be first field in structure) */
91 	unsigned long	ksp;
92 	unsigned long	ksp_limit;	/* if ksp <= ksp_limit stack overflow */
93 	void		*pgdir;		/* root of page-table tree */
94 	struct pt_regs	*regs;		/* Pointer to saved register state */
95 };
96 
97 #  define INIT_THREAD { \
98 	.ksp   = sizeof init_stack + (unsigned long)init_stack, \
99 	.pgdir = swapper_pg_dir, \
100 }
101 
102 /* Free all resources held by a thread. */
103 static inline void release_thread(struct task_struct *dead_task)
104 {
105 }
106 
107 unsigned long get_wchan(struct task_struct *p);
108 
109 /* The size allocated for kernel stacks. This _must_ be a power of two! */
110 # define KERNEL_STACK_SIZE	0x2000
111 
112 /* Return some info about the user process TASK.  */
113 #  define task_tos(task)	((unsigned long)(task) + KERNEL_STACK_SIZE)
114 #  define task_regs(task) ((struct pt_regs *)task_tos(task) - 1)
115 
116 #  define task_pt_regs_plus_args(tsk) \
117 	((void *)task_pt_regs(tsk))
118 
119 #  define task_sp(task)	(task_regs(task)->r1)
120 #  define task_pc(task)	(task_regs(task)->pc)
121 /* Grotty old names for some.  */
122 #  define KSTK_EIP(task)	(task_pc(task))
123 #  define KSTK_ESP(task)	(task_sp(task))
124 
125 /* FIXME */
126 #  define deactivate_mm(tsk, mm)	do { } while (0)
127 
128 #  define STACK_TOP	TASK_SIZE
129 #  define STACK_TOP_MAX	STACK_TOP
130 
131 #ifdef CONFIG_DEBUG_FS
132 extern struct dentry *of_debugfs_root;
133 #endif
134 
135 #  endif /* __ASSEMBLY__ */
136 # endif /* CONFIG_MMU */
137 #endif /* _ASM_MICROBLAZE_PROCESSOR_H */
138