1/* processor.h: FRV processor definitions
  2 *
  3 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
  4 * Written by David Howells (dhowells@redhat.com)
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License
  8 * as published by the Free Software Foundation; either version
  9 * 2 of the License, or (at your option) any later version.
 10 */
 11
 12#ifndef _ASM_PROCESSOR_H
 13#define _ASM_PROCESSOR_H
 14
 15#include <asm/mem-layout.h>
 16
 17#ifndef __ASSEMBLY__
 18/*
 19 * Default implementation of macro that returns current
 20 * instruction pointer ("program counter").
 21 */
 22#define current_text_addr() ({ __label__ _l; _l: &&_l;})
 23
 24#include <linux/compiler.h>
 25#include <linux/linkage.h>
 26#include <asm/sections.h>
 27#include <asm/segment.h>
 28#include <asm/fpu.h>
 29#include <asm/registers.h>
 30#include <asm/ptrace.h>
 31#include <asm/current.h>
 32#include <asm/cache.h>
 33
 34/* Forward declaration, a strange C thing */
 35struct task_struct;
 36
 37/*
 38 *  CPU type and hardware bug flags. Kept separately for each CPU.
 39 */
 40struct cpuinfo_frv {
 41#ifdef CONFIG_MMU
 42	unsigned long	*pgd_quick;
 43	unsigned long	*pte_quick;
 44	unsigned long	pgtable_cache_sz;
 45#endif
 46} __cacheline_aligned;
 47
 48extern struct cpuinfo_frv __nongprelbss boot_cpu_data;
 49
 50#define cpu_data		(&boot_cpu_data)
 51#define current_cpu_data	boot_cpu_data
 52
 53/*
 54 * Bus types
 55 */
 56#define EISA_bus 0
 57
 58struct thread_struct {
 59	struct pt_regs		*frame;		/* [GR28] exception frame ptr for this thread */
 60	struct task_struct	*curr;		/* [GR29] current pointer for this thread */
 61	unsigned long		sp;		/* [GR1 ] kernel stack pointer */
 62	unsigned long		fp;		/* [GR2 ] kernel frame pointer */
 63	unsigned long		lr;		/* link register */
 64	unsigned long		pc;		/* program counter */
 65	unsigned long		gr[12];		/* [GR16-GR27] */
 66	unsigned long		sched_lr;	/* LR from schedule() */
 67
 68	union {
 69		struct pt_regs		*frame0;	/* top (user) stack frame */
 70		struct user_context	*user;		/* userspace context */
 71	};
 72} __attribute__((aligned(8)));
 73
 74extern struct pt_regs *__kernel_frame0_ptr;
 75extern struct task_struct *__kernel_current_task;
 76
 77#endif
 78
 79#ifndef __ASSEMBLY__
 80#define INIT_THREAD_FRAME0 \
 81	((struct pt_regs *) \
 82	(sizeof(init_stack) + (unsigned long) init_stack - sizeof(struct user_context)))
 83
 84#define INIT_THREAD {				\
 85	NULL,					\
 86	(struct task_struct *) init_stack,	\
 87	0, 0, 0, 0,				\
 88	{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },	\
 89	0,					\
 90	{ INIT_THREAD_FRAME0 },			\
 91}
 92
 93/*
 94 * do necessary setup to start up a newly executed thread.
 95 * - need to discard the frame stacked by init() invoking the execve syscall
 96 */
 97#define start_thread(_regs, _pc, _usp)			\
 98do {							\
 99	__frame = __kernel_frame0_ptr;			\
100	__frame->pc	= (_pc);			\
101	__frame->psr	&= ~PSR_S;			\
102	__frame->sp	= (_usp);			\
103} while(0)
104
105/* Free all resources held by a thread. */
106static inline void release_thread(struct task_struct *dead_task)
107{
108}
109
110extern asmlinkage int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
111extern asmlinkage void save_user_regs(struct user_context *target);
112extern asmlinkage void *restore_user_regs(const struct user_context *target, ...);
113
114#define copy_segments(tsk, mm)		do { } while (0)
115#define release_segments(mm)		do { } while (0)
116#define forget_segments()		do { } while (0)
117
118/*
119 * Free current thread data structures etc..
120 */
121static inline void exit_thread(void)
122{
123}
124
125/*
126 * Return saved PC of a blocked thread.
127 */
128extern unsigned long thread_saved_pc(struct task_struct *tsk);
129
130unsigned long get_wchan(struct task_struct *p);
131
132#define	KSTK_EIP(tsk)	((tsk)->thread.frame0->pc)
133#define	KSTK_ESP(tsk)	((tsk)->thread.frame0->sp)
134
135#define cpu_relax()    barrier()
136
137/* data cache prefetch */
138#define ARCH_HAS_PREFETCH
139static inline void prefetch(const void *x)
140{
141	asm volatile("dcpl %0,gr0,#0" : : "r"(x));
142}
143
144#endif /* __ASSEMBLY__ */
145#endif /* _ASM_PROCESSOR_H */