1/*
2 * OpenRISC Linux
3 *
4 * Linux architectural port borrowing liberally from similar works of
5 * others.  All original copyrights apply as per the original source
6 * declaration.
7 *
8 * OpenRISC implementation:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
11 * et al.
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 */
18
19#ifndef __ASM_OPENRISC_PROCESSOR_H
20#define __ASM_OPENRISC_PROCESSOR_H
21
22#include <asm/spr_defs.h>
23#include <asm/page.h>
24#include <asm/ptrace.h>
25
26#define STACK_TOP       TASK_SIZE
27#define STACK_TOP_MAX	STACK_TOP
28/* Kernel and user SR register setting */
29#define KERNEL_SR (SPR_SR_DME | SPR_SR_IME | SPR_SR_ICE \
30		   | SPR_SR_DCE | SPR_SR_SM)
31#define USER_SR   (SPR_SR_DME | SPR_SR_IME | SPR_SR_ICE \
32		   | SPR_SR_DCE | SPR_SR_IEE | SPR_SR_TEE)
33/*
34 * Default implementation of macro that returns current
35 * instruction pointer ("program counter").
36 */
37#define current_text_addr() ({ __label__ _l; _l: &&_l; })
38
39/*
40 * User space process size. This is hardcoded into a few places,
41 * so don't change it unless you know what you are doing.
42 */
43
44#define TASK_SIZE       (0x80000000UL)
45
46/* This decides where the kernel will search for a free chunk of vm
47 * space during mmap's.
48 */
49#define TASK_UNMAPPED_BASE      (TASK_SIZE / 8 * 3)
50
51#ifndef __ASSEMBLY__
52
53struct task_struct;
54
55struct thread_struct {
56};
57
58/*
59 * At user->kernel entry, the pt_regs struct is stacked on the top of the
60 * kernel-stack.  This macro allows us to find those regs for a task.
61 * Notice that subsequent pt_regs stackings, like recursive interrupts
62 * occurring while we're in the kernel, won't affect this - only the first
63 * user->kernel transition registers are reached by this (i.e. not regs
64 * for running signal handler)
65 */
66#define user_regs(thread_info)  (((struct pt_regs *)((unsigned long)(thread_info) + THREAD_SIZE - STACK_FRAME_OVERHEAD)) - 1)
67
68/*
69 * Dito but for the currently running task
70 */
71
72#define task_pt_regs(task) user_regs(task_thread_info(task))
73
74#define INIT_SP         (sizeof(init_stack) + (unsigned long) &init_stack)
75
76#define INIT_THREAD  { }
77
78
79#define KSTK_EIP(tsk)   (task_pt_regs(tsk)->pc)
80#define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
81
82
83void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp);
84void release_thread(struct task_struct *);
85unsigned long get_wchan(struct task_struct *p);
86
87/*
88 * Free current thread data structures etc..
89 */
90
91extern inline void exit_thread(void)
92{
93	/* Nothing needs to be done.  */
94}
95
96/*
97 * Return saved PC of a blocked thread. For now, this is the "user" PC
98 */
99extern unsigned long thread_saved_pc(struct task_struct *t);
100
101#define init_stack      (init_thread_union.stack)
102
103#define cpu_relax()     barrier()
104#define cpu_relax_lowlatency() cpu_relax()
105
106#endif /* __ASSEMBLY__ */
107#endif /* __ASM_OPENRISC_PROCESSOR_H */
108