1/*
  2 *  Port on Texas Instruments TMS320C6x architecture
  3 *
  4 *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
  5 *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
  6 *
  7 *  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
  8 *
  9 *  This program is free software; you can redistribute it and/or modify
 10 *  it under the terms of the GNU General Public License version 2 as
 11 *  published by the Free Software Foundation.
 12 */
 13#ifndef _ASM_C6X_PROCESSOR_H
 14#define _ASM_C6X_PROCESSOR_H
 15
 16#include <asm/ptrace.h>
 17#include <asm/page.h>
 18#include <asm/current.h>
 19
 20/*
 21 * Default implementation of macro that returns current
 22 * instruction pointer ("program counter").
 23 */
 24#define current_text_addr()			\
 25({						\
 26	void *__pc;				\
 27	asm("mvc .S2 pce1,%0\n" : "=b"(__pc));	\
 28	__pc;					\
 29})
 30
 31/*
 32 * User space process size. This is mostly meaningless for NOMMU
 33 * but some C6X processors may have RAM addresses up to 0xFFFFFFFF.
 34 * Since calls like mmap() can return an address or an error, we
 35 * have to allow room for error returns when code does something
 36 * like:
 37 *
 38 *       addr = do_mmap(...)
 39 *       if ((unsigned long)addr >= TASK_SIZE)
 40 *            ... its an error code, not an address ...
 41 *
 42 * Here, we allow for 4096 error codes which means we really can't
 43 * use the last 4K page on systems with RAM extending all the way
 44 * to the end of the 32-bit address space.
 45 */
 46#define TASK_SIZE	0xFFFFF000
 47
 48/*
 49 * This decides where the kernel will search for a free chunk of vm
 50 * space during mmap's. We won't be using it
 51 */
 52#define TASK_UNMAPPED_BASE	0
 53
 54struct thread_struct {
 55	unsigned long long b15_14;
 56	unsigned long long a15_14;
 57	unsigned long long b13_12;
 58	unsigned long long a13_12;
 59	unsigned long long b11_10;
 60	unsigned long long a11_10;
 61	unsigned long long ricl_icl;
 62	unsigned long  usp;		/* user stack pointer */
 63	unsigned long  pc;		/* kernel pc */
 64	unsigned long  wchan;
 65};
 66
 67#define INIT_THREAD					\
 68{							\
 69	.usp = 0,					\
 70	.wchan = 0,					\
 71}
 72
 73#define INIT_MMAP { \
 74	&init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, \
 75	NULL, NULL }
 76
 77#define task_pt_regs(task) \
 78	((struct pt_regs *)(THREAD_START_SP + task_stack_page(task)) - 1)
 79
 80#define alloc_kernel_stack()	__get_free_page(GFP_KERNEL)
 81#define free_kernel_stack(page) free_page((page))
 82
 83
 84/* Forward declaration, a strange C thing */
 85struct task_struct;
 86
 87extern void start_thread(struct pt_regs *regs, unsigned int pc,
 88			 unsigned long usp);
 89
 90/* Free all resources held by a thread. */
 91static inline void release_thread(struct task_struct *dead_task)
 92{
 93}
 94
 95extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 96
 97#define copy_segments(tsk, mm)		do { } while (0)
 98#define release_segments(mm)		do { } while (0)
 99
100/*
101 * saved PC of a blocked thread.
102 */
103#define thread_saved_pc(tsk) (task_pt_regs(tsk)->pc)
104
105/*
106 * saved kernel SP and DP of a blocked thread.
107 */
108#ifdef _BIG_ENDIAN
109#define thread_saved_ksp(tsk) \
110	(*(unsigned long *)&(tsk)->thread.b15_14)
111#define thread_saved_dp(tsk) \
112	(*(((unsigned long *)&(tsk)->thread.b15_14) + 1))
113#else
114#define thread_saved_ksp(tsk) \
115	(*(((unsigned long *)&(tsk)->thread.b15_14) + 1))
116#define thread_saved_dp(tsk) \
117	(*(unsigned long *)&(tsk)->thread.b15_14)
118#endif
119
120extern unsigned long get_wchan(struct task_struct *p);
121
122#define KSTK_EIP(task)	(task_pt_regs(task)->pc)
123#define KSTK_ESP(task)	(task_pt_regs(task)->sp)
124
125#define cpu_relax()		do { } while (0)
126
127extern const struct seq_operations cpuinfo_op;
128
129/* Reset the board */
130#define HARD_RESET_NOW()
131
132extern unsigned int c6x_core_freq;
133
134
135extern void (*c6x_restart)(void);
136extern void (*c6x_halt)(void);
137
138#endif /* ASM_C6X_PROCESSOR_H */